Summer Ferreira, Sandia National Laboratories
Judy Jeevarajan, Underwriters Laboratories Inc.
Hiroyuki Kubo, National Institute of Technology and Evaluation
Brittany Westlake, Electric Power Research Institute
Wednesday PM, November 29, 2017
Hynes, Level 3, Room 309
1:30 PM - *ES05.01.01
Lithium Battery Safety—Problems and Solutions
Rengaswamy (Srini) Srinivasan 1 , Bliss Carkhuff 1 , Plamen Demirev 1 Show Abstract
1 Applied Physics Laboratory, Johns Hopkins University, Laurel, Maryland, United States
During the last decade, the production and use of rechargeable lithium batteries has increased tenfold. This technology, commercially introduced in 1991, has helped revolutionize the cellphone and mobile computing device markets. Nowadays, lithium batteries pack at least twice the energy compared to fifteen years ago. The increased energy density is propelling battery use in electric vehicles and beyond. Recently publicized battery fires and explosions, as in e-cigarettes and the Samsung Galaxy 7, point to the existing technological challenges. Battery safety issues and solutions, developed at the Applied Physics Laboratory (APL), will be discussed in this talk.
Multi-cell batteries face a unique problem that single-cell Li-ion batteries do not: mismatching of one or more cells is detrimental to the safety and efficiency of the entire battery. Thus, cell matching is an important first step required for safe operation of multi-cell Li-ion batteries. Cell mismatch can occur due to battery over-discharge, over-charge, internal and external shorts, etc., or even when leaving a battery unused for an extended period (calendar ageing). Predicting a mismatch is essential for a battery’s thermal safety and electrical efficiency.
Starting in 2009, APL has been designing and testing Battery Internal Temperature-based Battery Management Systems (BITS-BMS) centered on monitoring individual cell’s internal temperature. The current device is a small low-power, multi-frequency (1Hz – 1000 Hz) impedance-based BMS for multi-cell batteries of varying capacities. Compared to conventional BMS, the APL BITS-BMS ensures battery safety and efficiency by tracking and acting on emerging mismatches and other electrical and thermal abnormalities in each individual cell without adding cost, volume, weight and power.
Conventional BMS typically monitor cell voltages and surface temperature. However, these measurements and related protocols have not succeeded in ensuring battery safety or improving efficiency. Data for batteries with intentionally calendar-aged and over-discharged cells convincingly demonstrate that such BMS cannot identify cell mismatches and emerging failures. In contrast, the APL-developed impedance-based BMS tracks, identifies and acts on changes in the internal state of each cell continuously in real time, including battery charging, discharging and at rest.
2:00 PM - *ES05.01.02
Energy Storage Material Choices to Avoid Thermal Runaway in Lithium-Ion Batteries
John Hewson 1 Show Abstract
1 , Sandia National Laboratories, Albuquerque, New Mexico, United States
The increase in electrochemical energy density associated with modern energy storage is driven by inherently more reactive material systems. With this reactivity, the activation barrier that must be overcome before inadvertently releasing energy can be lower than practitioners are accustomed to dealing with, and this presents safety challenges. Such inadvertent energy release is referred to as thermal runaway when it exhibits dangerous acceleration as the system is heated.
This presentation will review the critical conditions that lead to thermal runaway for a given chemical system. The discussion will then focus on the thermodynamic, kinetic and transport processes that limit thermal runaway for typical systems. Interestingly, traditional lithium-ion designs exhibit all of these processes to some degree.
For situations where localized thermal runaway cannot be prevented, it is important to understand the processes related to the propagation of failure beyond the initial site. This involves different chemical processes that will be discussed, though the available understanding of the material-specific details is more limited.
While most descriptions of thermal runaway have been limited in describing specific material processes, identifying these processes can aid in the design of materials that have improved safety characteristics. We suggest that determining the relevant safety-related material characteristics during the development process is possible with basic material science understanding, bringing a tighter link between material science and battery safety.
3:30 PM - ES05.01.03
In Situ Measurement of Mechanical Property and Stress Evolution in a Composite Silicon Electrode
Dawei Li 1 2 , Yang-Tse Cheng 1 , Junqian Zhang 3 Show Abstract
1 , University of Kentucky, Lexington, Kentucky, United States, 2 Shanghai Institute of Applied Mathematics and Mechanics, Shanghai University, Shanghai China, 3 Department of Mechanics, Shanghai University, Shanghai China
Mechanical properties and lithiation-induced stress are crucial to the performance and durability of lithium-ion batteries. Here, we report the evolution of elastic modulus and stress in a silicon/polyvinylidene fluoride (PVDF) composite electrode deposited on a copper foil, along with a mechanics model for analyzing the large change in the radius of curvature of the composite electrode. The curvature change of the electrode is captured using a video camera during lithiation/delithiation. The elastic modulus decreases from ca.0.63 GPa to ca. 0.1 GPa in lithiation and is much smaller during delithiation process, which is caused by the fracture of the electrode. The magnitude of the compressive stress increases lineally during lithiation and decreases suddenly to reach a steady state value during delithiation.
3:45 PM - ES05.01.04
Advanced Thermal Management for Hybrid Energy Storage Modules (HESM)
Frank Puglia 1 , Marco Amrhein 3 , John Chang 4 , Keith Cleek 2 Show Abstract
1 , EaglePicher, East Greenwich, Rhode Island, United States, 3 , PCKA, West Lafayette, Indiana, United States, 4 , LLNL, Livermore, California, United States, 2 , Northrup Grumman, Redondo Beach, California, United States
The increase in both specific energy and specific power of Lithium-ion batteries has resulted in a need for improved thermal management. This thermal control is needed not only for maximized life during normal operation but for improved safety during failure modes. Improved safety can be defined two ways. The first is reducing the risk of, or magnitude of, an initial failure. The second, and more important, is mitigating the risk of cell to cell fratricide (propagation). This paper reviews the thermal related results of the two Hybrid Energy Storage Module (HESM) programs that the Yardney Division of EaglePicher Technologies, LLC (EPY) was awarded. In HESM Area #3, the team of Lawrence Livermore National Laboratory, The University of Rhode Island, and EaglePicher developed a redundant, highly efficient thermal control system for lithium ion batteries. The main advantage of this technology over other approaches is the highly volumetrically efficient cooling plates. In modeled, simulated, and induced thermal events on real cells, the thermal energy that reached the cells nearest to the failing cell was insignificant. In HESM Area #1, the team of Lawrence Livermore National Laboratory, P.C. Krause and Associates (PCKA), Northrop Grumman, and EaglePicher developed a hybrid, full scale, aircraft load leveling system. This system is capable of handling 100+kW continuous loads and bidirectional, 240kW pulse loads while still maintaining compliance with MIL-STD-704. A key feature of this system is that the combination of the battery, capacitor and ultrahigh efficient dc-dc converters are far more thermally efficient than a typical generator attempting to meet the dynamic loads on its own. Thus, the design offers an opportunity to reduce the total thermal load on the platform while also improving electrical power quality in the dc distribution system. This combination allows for additional electrical power capability to be utilized on future More Electric Aircraft (MEA). The combination of the advancements from these two programs increases both the efficiency and operational performance of the energy storage system while also improving the overall application safety for a wide range of both high power and high energy applications.
4:00 PM - ES05.01.05
Li-Mg Hybrid Battery with Vanadium Oxychloride as Electrode Material
Christian Bonatto Minella 2 1 , Ping Gao 2 , Zhirong Zhao-Karger 2 1 , Thomas Diemant 3 , Rolf Behm 2 3 , Maximilian Fichtner 2 1 Show Abstract
2 , Helmholtz Institute Ulm (HIU), Ulm Germany, 1 , Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen Germany, 3 Institute of Surface Chemistry and Catalysis, Ulm University, Ulm Germany
Lithium-ion batteries (LIBs) could theoretically offer 2061 mA h cm-3 when metallic lithium (Li) is used as anode. However, because of the formation of dendrite structures over cycling, in practice, graphite has to be employed instead of Li (837 mA h cm-3 for graphite). The dendrite structures could generate short-circuits and overheats and therefore represent a crucial safety issue. On the contrary, metallic magnesium (Mg) as alternative negative electrode offers several other advantages such as higher theoretical volumetric capacity (3833 mA h cm-3), stability in air and abundance in the earth crust compared to lithium metal.. Nevertheless, the double charge that it carries, reflects in a sluggish diffusion kinetics upon discharge/charges.[3,4]
An hybrid electrochemical device that contains a metallic Mg anode, a Li intercalation cathode and a Li/Mg-electrolyte is regarded as a solution to circumvent the intrinsic drawbacks linked to both Li- and Mg-electrochemistry.
In this study, the properties of a cell composed of metallic magnesium anode, a vanadium oxychloride (VOCl) intercalation cathode and a Li-Mg hybrid electrolyte were investigated. The chosen electrolyte is 1.5 M (HMDS)2Mg–2AlCl3 (HMDS=hexamethyldisilazide) in tetrahydrofuran (THF) and tetraglyme (G4) (1:1 in vol.) solvent mixtures. Lithium was added to the electrolyte in form of LiCl with a concentration of 0.5 M.
The galvanostatic charge/discharge tests revealed a specific capacity of 195 mA h g-1 at 100 mA g-1. This value dropped to 130 mA h g-1 after 100 cycles with a coulombic efficiency of 97.5 %. At 200 mA g-1, after first discharge, the cell provided 150 mA h g-1. After 100 cycles, 120 mA h g-1 was still measured. At 500 mA g-1 the cell produced 150 and 105 mA h g-1 after 1st and 100th cycle respectively. After 800 cycles, ca. 75 mA h g-1 were still measured. Both batteries, tested at 200 and 500 mA g-1, cycled with a coulombic efficiency of 99.5 and 99.8 % respectively. These values are remarkable considering that 200 and 500 mA g-1 correspond to 1.3 and 3.3C.
X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) revealed that is lithium rather than magnesium that reacted with VOCl following an initial intercalation process which led to the expansion of its interlayer structure and a final conversion reaction to LiCl and VO. The co-deposition of lithium at the anode, the formation of Li-Mg alloys or contribution of any side reactions could be ruled out.
R. Mohtadi, F. Mizuno, Beilstein J. Nanotechnol. 2014, 5, 1291–1311.
J.-M. Tarascon, M. Armand, Nature 2001, 414, 359-367.
D. Aurbach, I. Weissman, Y. Gofer, E. Levi, Chem. Rec. 2003, 3, 61.
E. Levi, Y. Gofer, D. Aurbach, Chem. Mater. 2010, 22, 860.
Z. Zhao-Karger, X. Lin, C. Bonatto Minella, D. Wang, T. Diemant, R. J.Behm, M. Fichtner, J. Power Sources 2016, 323, 213–219.
4:15 PM - ES05.01.06
Microstructure and Phase Change on Iron Anodes for Nickel-Iron Batteries
Dong-Chan Lee 1 , Gleb Yushin 1 Show Abstract
1 , Georgia Institute of Technology, Atlanta, Georgia, United States
A demand for large-scale energy storage systems has continuously arisen to store the excess energy during the electricity producing periods and release it during the electricity demanding periods. Although lithium-ion batteries are widely used due to their high energy density and efficiency, the simultaneous demand on cost, safety and durability for the gird-scale applications presents a tremendous challenge to the deployment of such commercially available systems. A renewed interest on Ni-Fe aqueous battery systems awakes due to their environmental friendliness, low cost, long life and robustness against harsh conditions as well as the compatibility with intermittent power sources such as wind power and photovoltaics. The challenge for improved Ni-Fe batteries, however, remains limiting their utilization for large-scale electricity grid: electrolyte decomposition, high self-discharge and poor cell efficiency. Such drawbacks can be overcome by sound understanding on the cell reactions happening at the electrodes.
By the cyclic voltammetry with micro-sized iron particles in three-electrode cells, we observed their characteristic behaviors which can be categorized into three stages with different tendencies on capacity and efficiency: increasing (Stage I: Development), maintaining (Stage II: Retention) and decreasing: (Stage III: Failure). Post-mortem analysis using SEM enabled us to visualize the microstructure change on iron particles during the development stage. When the particle pulverization subsided at the end of Stage I, the evolution of new iron oxide phase was detected by XRD. Through the retention stage as an intermediate, iron anodes exhibited the accumulation of electrochemically less reactive oxide species which is considered as the origin of capacity fading during the failure stage. Along with XRD, we used Raman spectroscopy to obtain the detailed information on the oxidation state of accumulated oxide and successfully combined it with the CV results from multiple class of iron oxides. Overall, we confirmed that the microstructure change takes over during early charge-discharge cycles of iron anodes while their phase change is dominant at later stage which is the key for the rationale explaining the failure mechanism of iron anodes in Ni-Fe batteries.
ES05.02: Novel Materials Beyond Lithium-Ion I
Wednesday PM, November 29, 2017
Hynes, Level 3, Room 309
4:30 PM - ES05.02.01
A Materials Chemistry Approach to Safe, Effective Sodium Batteries
Erik Spoerke 1 , Leo Small 1 , Sai Bhavaraju 2 , Alexis Eccleston 2 , Eric Allcorn 1 , Joshua Lamb 1 , Paul Clem 1 Show Abstract
1 , Sandia National Laboratories, Albuquerque, New Mexico, United States, 2 , Ceramatec, Inc., Salt Lake City, Utah, United States
Developing safe, low-cost, effective solutions to evolving grid-scale electrical energy storage challenges remains a national priority, essential for revitalization of a complex and demanding national grid infrastructure. Sodium-based batteries show promise for grid-scale storage, offering high performance with long cycle life and inherent, engineered improvements in battery safety. Here, we describe molten salt-based batteries that integrate molten sodium anodes, NaSICON solid state electrolytes, and AlCl3-based molten salt catholytes to create high performance battery constructs that operate below 200oC. The inherent nature of the material chemistries in these all-inorganic systems eliminates common hazards associated with runaway exothermic reactions, polymer separators, and organic electrolytes that plague other battery systems. Here, we specifically highlight recent advances in materials chemistry of Na-NiCl2 and developing Na-I2 batteries. By refining the composition and chemistry of the molten salt catholyte, we influence catholyte performance and tune chemical and ionic interactions at both the separator and current collector interfaces. Not only do these changes stand to improve battery performance, but the nature of the chemistries in these systems makes them fundamentally safer as well. Accelerated rate calorimetry reveals neither runaway exothermic reactions, nor hazardous pressurized gas generation that make other battery systems inherently more hazardous in nature. Continued improvement in battery performance through refinement of the materials chemistry in these molten-salt sodium batteries promises new opportunities to impact a growing national need for safe, robust grid-scale storage.
Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.
ES05.03: Poster Session
Wednesday PM, November 29, 2017
Hynes, Level 1, Hall B
8:00 PM - ES05.03.01
A Hybrid Physics-Based and Data-Driven Approach for Online Identification of Degradation Mechanisms of Lithium-Ion Battery
Yu Hui Lui 1 , Shan Hu 1 , Chao Hu 2 Show Abstract
1 Department of Mechanical Engineering, Iowa State University, Ames, Iowa, United States, 2 Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa, United States
Among various electrochemical energy storage systems, lithium-ion rechargeable batteries (LIBs) stand out for their high specific energy (Wh/kg) and energy density (Wh/L), compared to other battery chemistries. With the emerging applications such as electric vehicles (EVs), hybrid electric vehicles (HEVs), and grid-scale energy storage, strategies to accurately assess the current and future degradation of LIBs are crucial for safe and reliable operation of these batteries throughout their lifetime.1,2 Existing battery management systems (BMSs) mainly estimate the state of charge (SOC) and state of health (SOH) of a battery, and simply extrapolate a capacity fade model to estimate the battery remaining useful life without understanding the underlying degradation mechanisms of the battery. In this work, a new battery prognosis framework is established by coupling high-fidelity physics-based models of individual or interacting degradation mechanisms with differential voltage (dVdQ) analysis and extreme learning machine. This new framework could pinpoint the degradation mechanism(s) underlying the observed capacity fade and provide valuable information for battery health management.
Pseudo-two-dimensional (P2D) electrochemical model developed by Newman’s group3,4, produces high accuracy simulation, but the real-time implementation of such model is computationally demanding. Besides, dVdQ analysis has been used extensively by Dahn’s group to analyze battery charge and discharge curves for diagnosing three major degradation mechanisms: loss of lithium inventory (LLI), and losses of active mass (LAMs) of both electrodes. The diagnosis quantifies the degrees of degradation from these mechanisms through fitting the full-cell voltage versus capacity curve measured from a real battery to a half-cell model.5,6 However, multiple degradation mechanisms may happen simultaneously in a real LIB, and it could be challenging to decouple their effects with dVdQ analysis.
In here, we present the possibility of extracting characteristic features (locations and heights of peaks) from dVdQ of the synthetic charge/discharge data generated from P2D model using COMSOL Multiphysics, for three different degradation parameters, namely LLI due to SEI growth and LAMs of both electrodes. The relationship between the characteristic features and the degradation parameters under various degradation scenarios is exploited for degradation analysis through the use of a machine learning algorithm (i.e. extreme learning machine). The algorithm, after being trained, can quantify specific degradation mechanisms based on the features extracted from a newly generated dVdQ curve with unknown degradation mechanisms. Incorporation of such algorithm into existing BMSs would enable battery maintenance personnel and control electronics to perform predictive maintenance and control that would help build resilience into the operation of LIBs.
8:00 PM - ES05.03.02
N, F Co-Doped Activated Carbon for Supercapacitors
Juyeon Kim 1 , Kwang Chul Roh 1 Show Abstract
1 , Korea Institute of Ceramic Engineering and Technology, Jinju-si Korea (the Republic of)
Activated carbon has low electrical conductivity and reliability than other carbonaceous materials because the activation process makes oxygen functional groups. To overcome these problems, activated carbon was reduced the oxygen functional groups by heteroatom co-doping. In the present work, N, F co-doped activated carbon (AC-NF) was successfully prepared by the microwave-assisted hydrothermal method, utilizing commercial activated carbon (AC-R) as a precursor and ammonium tetrafluoroborate as a one-pot N, F co-doping source. AC-NF exhibited excellent electrical conductivity (3.8 S cm–1) and showed N and F contents of 0.6 and 0.1 at%, respectively. The introduction of N and F improves the performance of supercapacitors: a high capacitance of 14.6 F cm-3 at 0.5 mA cm-2 are reported. Notably, N, F co-doped activated carbon exhibits excellent rate capability (74%), which is high compared to those of the raw activated carbon (53%) because co-doping with N and F can increase electrical conductivity between doping elements and activated carbon. The developed N,F co-doping method from a single source is cost effective and yields AC-NF with excellent electrochemical properties, making it a promising method for the commercialization of energy storage devices.
8:00 PM - ES05.03.03
The Capacitive Effect of Activated Carbon Decorated with Graphene Quantum Dots
Su-jin Jang 1 , Kwang Chul Roh 1 Show Abstract
1 , Korea Institute of Ceramic Engineering & Technology, Jinju-si Korea (the Republic of)
The activated carbon (AC) decorated with graphene quantum dots (GQDs) is synthesized by alkali activation from carbonaceous precursor with turbostratic structure. As comparison of GQDs and alkali activation mechanism, metallic K expand the graphene layer stacks and then decompose epoxy group and other functional group into quantum size. From the high-resolution transmission electron microscopy (HR-TEM), GQDs in 5 - 10 nm range size are dispersed on disordered micropores carbon. The obtained ACs in low KOH reagent content has tendency plenty more GQDs. HR-TEM images elucidates the 0.268nm interlayer spacing of GQD similar to interlayer distance in XRD. The excellent crystalline structure of GQDs is favourable to increase the electrical conductivity and capacitive effect. The electrochemical performance of the obtained ACs has been studied with cyclic voltammetry, galvanostatic charge/discharge and ac impedance spectroscopy. Cyclic voltammetry shows redox reaction of GQDs, and increased capacitance up to 114.8 F/cc.
8:00 PM - ES05.03.04
High Energy Density Nano-Enhanced Lithium-Ion Batteries for Space Applications
Martin Dann 1 , Stephen Polly 1 , Matthew Ganter 1 , Chris Schauerman 1 , Brian Landi 1 , Ryne Raffaelle 1 Show Abstract
1 , Rochester Institute of Technology, Rochester, New York, United States
Nanomaterials have demonstrated the ability to push the limits of existing technologies in the aerospace industry and abroad. Successful integration of nanomaterials, such as carbon nanotubes (CNTs), into devices and components has been shown to drastically improve their performance metrics by reducing mass and improving mechanical and electrical properties. Ideally, these nano-enhanced components will act as drop-in replacements for current form-factors used by the aerospace industry. Further demonstration of the use of these nano-enhanced components in a small satellite can help the aerospace industry expand the use of this technology.
Specifically, the use of CNTs in wire harnesses, and lithium ion batteries can increase the device performance without significantly altering the device dimensions or the device’s operating range. In many cases, the use of CNTs widens the viable range of operating conditions, such as increased depth of discharge of lithium ion batteries, and increased flexure tolerance of wire harnesses.
Lithium ion batteries are the current leader in the energy storage field due to the increased energy density and performance over other rechargeable chemistries. CNTs are an excellent material for use in lithium ion batteries because of their electrochemical and mechanical properties. The use of CNTs as a conductive additive has been shown to be more effective in establishing an electrical percolation network than traditional carbon black or graphite. The integration of CNTs into lithium-ion batteries can also be used to increase the areal capacity of the electrodes, thus increasing the specific energy density of the entire cell. In order to reach high energy densities, it becomes necessary to reduce the weight of components that do not contribute to the capacity of the cell. CNTs in lithium-ion batteries can yield a specific energy density > 300 Wh/kg, in comparison to typical commercial cells which have a specific energy density of 100 – 200 Wh/kg.
Commercial lithium ion batteries used for space applications were acquired and tested via a rate test under various charge (C)-rates, as well as under low earth orbit (LEO) cycle conditions. Lithium ion batteries with an energy density of 260 Wh/kg have been created without the use of CNT additives by optimizing the ratio of capacity-active to capacity-inactive components in the cell. Comparatively, lithium ion batteries with an energy density of 280 Wh/kg have been created with the use of CNT additives. The performance of these cells has been tested via rate test at various C-rates, and under LEO cycle conditions. Raman spectroscopy, thermogravimetric analysis, and scanning electron microscope were also used to characterize the CNTs used in this study. The overall performance of the commercial cells, and the high energy density cells (with and without CNT additives) were compared based on several testing procedures listed under NASA testing guidelines.
8:00 PM - ES05.03.05
High-Performance Supercapacitor Applications of Metal Oxide-Nanoparticle-Decorated Millimeter-Long Vertically Aligned Carbon Nanotube Arrays via an Effective Supercritical CO2-Assisted Method
Junye Cheng 1 , Bin Zhao 2 , Wenkang Zhang 2 , Junhe Yang 2 , Wenjun Zhang 1 , Chun-Sing Lee 1 Show Abstract
1 Applied Physics Materials, City University of Hong Kong, Hong Kong Hong Kong, 2 School of Materials Science and Engineering, University of Shanghai for Science and Technology, Shanghai China
Abstract: Construction of high-energy density asymmetric supercapacitors is often hindered by unsatisfactory matching between the anode and cathode. Thus, it is crucial to develop composite anodes with high specific capacitance to match that of cathodes. In this work, NiO nanoparticles were distributed uniformly in the vertically aligned carbon nanotube arrays (VACNTs) with millimeter thickness by an effective supercritical carbon dioxide assisted method. The as-prepared VACNTs/NiO hybrid structures were used as electrodes without binders and conducting additives for supercapacitor applications. Due to the synergetic effects of NiO and VACNTs with nano-porous structures and parallel one-dimensional conductive paths for electrons, the supercapacitors exhibited a high capacitance of 1088.44 F g−1. Furthermore, an asymmetric supercapacitor was assembled using the as-synthesized VACNTs/NiO hybrids as the positive electrode and the VACNTs as the negative electrode. Remarkably, the energy density of the asymmetric supercapacitor was as high as 90.9 Wh kg−1 at 3.2 kW kg−1 and the maximum power density reached 25.6 kW kg−1 at 24.9 Wh kg−1, which were superior to those of the NiO or VACNTs based asymmetric supercapacitors. More importantly, the asymmetric supercapacitors exhibited capacitance retention of 87.1% after 2000 cycles at 5 A g−1. The work provides a novel approach in decorating highly dense and long VACNTs with active materials, which are promising electrodes for supercapacitors with ultra-high power density and energy density.
8:00 PM - ES05.03.06
Quantification of Rotational and Magnetic Disorder in Aprotic Sodium-Oxygen Batteries
Oleg Sapunkov 1 , Venkatasubramanian Viswanathan 1 Show Abstract
1 , Carnegie Mellon University, Pittsburgh, Pennsylvania, United States
In recent years, considerable research has been conducted on the metal-air battery group, due to its high theoretical energy density, both gravimetric and volumetric. At present, the Li-O2 battery is regarded to be the most promising member of the class, exhibiting the highest energy density of any known battery chemistry. Unfortunately, it suffers from electrolyte and electrode instability, as well as limited rechargeability and discharge capacity. Hartmann et al. have demonstrated a rechargeable Na-O2 battery, with the primary observed discharge product reported to be sodium superoxide (NaO2). Their battery shows superior cycle life and Coulombic efficiency to the best performing Li-O2batteries. Rigorous understanding of the Na-O2 battery reaction mechanism requires insight into the electronic structure throughout the phase space of sodium oxides. Nucleation, nanoscale stabilization, and surface energetics of various sodium-oxygen compounds have been examined through both ab initio Density Functional Theory calculations and experimental measurements. As a group, alkali superoxides are known to be highly disordered, both in internal geometry and magnetic ordering. It is crucial to map out disorder in room-temperature NaO2, considering its importance in determining electronic structure, surface energetics, and growth properties relevant to Na-O2 battery cycling. In this research, we aim to improve understanding of the electronic structure of bulk NaO2. We perform a series of DFT calculations to describe geometric and magnetic disorder in bulk NaO2. DFT-calculated energies are used to derive an Ising Model of interactions between oxygen dimer units within the bulk material. We find that both 2-body and 3-body nearest-neighbor interactions, which account for both the geometric and magnetic disorder of the structure, are critical to accurately describe bulk NaO2. Further, we extend the study to examine the role of next-nearest-neighbor interactions within the bulk; although these interactions are lower in energy, they influence long-range ordering within the bulk material. The constructed Ising Model is used within the framework of a Metropolis Monte Carlo simulation to calculate bulk properties for supercells of increased size; these simulations demonstrate phase transitions within the bulk material, which are most clearly seen within the largest simulated supercells. Further, we observe that the calculated bandgap of bulk NaO2 is strongly affected by the degree of internal disorder of the material.
8:00 PM - ES05.03.07
RGO/Si Nanosheet Composites Synthesized from Aromatic Amine Grafted Silicon as an Efficient Anode Material for Li-Ion Batteries
M. Jeevan Kumar Reddy 1 , Jae Ik Kim 1 , Pil Sung Choi 1 , Hyung Jin Moon 1 , A.M. Shanmugharaj 1 , Sung Hun Ryu 1 Show Abstract
1 , Kyung Hee University, Seoul Korea (the Republic of)
The main drawbacks of Lithium ion batteries start with higher capacity fade during long cycling, large volume expansion of electrode materials and etc. For overcoming these issues Si receives much attention as a replacement of graphite (372 mAh/g) due to its high theoretical specific capacity of about 4200 mAh/g. However, Si has a very huge volume expansion (about 300-400%) and lead to the cracking and pulverization of Si anode. This results on decay of capacity, cycle life and finally leading to cell failure. To overcome this kind of issues lot of solutions are tried such as modification in size, shape, structure, modification in synthesis procedure, alloying with other metals and etc., All efforts were made to buffer the volume change by introducing plenty of free spaces or enhancing the linkage of Si with other composites like carbon based materials. There has been several reports on zero dimensional (0D), two dimensional (2D), and three dimensional materials (3D). But the reports on 2D materials are very rare. The two dimensional (2D) structure combinations with Si are well ahead of particles to rectify the above discussed problems. 2D materials are very good in frame work for accommodating Li+ ion on their structure. 2D materials are made in several methods to get different shapes like nano ribbons, nanotubes, nanosheets etc. In this study we followed a unique method of preparation for overcoming the issues with Si anode and it turned to be a good anode material for Lithium ion battery with good cyclability and enhanced capacity than pristine CaSi2.
RGO-Si nanosheet composite materials were successfully synthesized from pristine CaSi2. Pristine was modified to Si nanosheets, which are grafted with amine. Respective amounts of RGO was added to the composite materials followed by pyrolysis at 500 oC. Successful formation of RGO-Si nanosheet composites where confirmed from FE-TEM analysis. This was further supported by XPS, XRD, HR-Raman and FT-IR analysis. BET Nitrogen adsorption studies showed significant increase of surface area for RGOSi nanosheet composite with respect to the percentage of RGO present in it. Electrochemical measurements demonstrated that RGO-Si based anode materials perform better in the cycling with 96% of columbic efficiency with excellent reversible capacity (RGO-Si-1(374 mAhg−1) , RGO-Si-2 (482 mAhg−1) and RGO-Si-3 (293 mAhg−1) respectively) than that of pristine CaSi2 (96 mAhg-1) at 0.1C rate. The draw backs of pristine material was rectified with the combination of RGO. Which include excellent electric conductivity due to the RGO (Si is semiconducting material by nature), efficient lithium-ion transport and controlled volume expansion due to Si nanosheets structures are sandwiched between RGO surface.
8:00 PM - ES05.03.08
Enhanced Sodium Storage through Carbon Quantum Dot MoS2 Nanosheets Grown on 3D Graphene
Glenn Sim 1 Show Abstract
1 , Singapore University of Technology and Design, Singapore Singapore
Owing to depletion of traditional nonrenewable fossil fuels and the environmental concerns that it brings, there has been a spike in the demand of renewable, sustainable and clean energy. The abundance of sodium in its natural state has drawn many to exploit its low cost for large scale energy storage production, posing as a competitor for Lithium Ion Batteries (LIB). Sodium Ion Batteries (SIB) have proven to be a suitable alternative to LIB as it would potentially cost less when scaled up. However, the major challenge in SIBs would be to find a suitable anode material that would possess a high specific capacity and a low redox potential.
As shown by Chen et al, 3DG boasts of an excellent architectural network structure with a high surface area, which serves as sites for material growth.  Two-dimensional (2D) molybdenum disulfide (MoS2) has been the center of attraction for a variety of applications, such as catalyst, energy storage devices, and wearable electronics, due to its high specific capacity abundance and low cost. However, many are still trying to overcome the challenges of low rate capability and poor cycling stability. 
In this work, we present 3D Graphene (3DG) that is obtained by chemical vapor deposition (CVD) method as shown in Figure 1, and growth of Molybdenum disulfide (MoS2) using a facile hydrothermal method, with 3DG as the substrate, exploiting the high surface area for growth that the 3DG provides. After the successful growth of MoS2 on 3DG as seen through the SEM and TEM images shown in Figure 2, the MoS2 nanosheets are further decorated with nitrogen doped graphene quantum dots (QD) through a one-step electrodeposition method . Leveraging on this binder free growth method, we used it as anode materials and found that it enhances sodium storage, improves capacity and paves the way for high energy density sodium anodes. Initial electrochemical tests which we have conducted and shown in Figure 3, shows that QD/MoS2/3DG SIB is able to deliver a reversible capacity of 550mAhg-1.
Keywords: 3D Graphene, Molybdenum Disulfide, Graphene Quantum Dots, Sodium ion batteries
Reference to a journal publication:
 Z. Chen, W. Ren, L. Gao, B. Liu, S. Pei and Hui-Ming Cheng*, Nature Materials, 10, 2011, 424-428
 J. Wang, C.Luo , T. Gao , A. Langrock , A. C. Mignerey, and C. Wang, Small, 11, 2015, 473-481
 Y. Yan, Q. Liu, H. Mao, K. Wang*, Journal of Electoanalytical Chemistry, 775, 2016, 1-7
8:00 PM - ES05.03.09
Giant Dielectric Constant in Al2O3 / TiO2 Nanolaminates Synthesized by Atomic Layer Deposition
Takuji Tsujita 1 2 , Yukihiro Morita 1 2 , Mikihiko Nishitani 2 Show Abstract
1 , Panasonic Corporation, Kadoma Japan, 2 , Osaka University, Suita Japan
High-permittivity materials have become the subject of vigorous development in recent years with the promise of applications in memory devices and capacitors, and research on multilayer films as high-permittivity materials has become a focus of strong interest. Wei Li et al. reported a high-permittivity material composed of Al2O3 and TiO2, which exhibited a giant dielectric constant (~1,000) due to Maxwell-Wagner relaxation(1). Using the same material, Geunhee Lee et al. reported a device structure that exhibits both giant dielectric constant and low dielectric loss (2).
Focusing on materials with this multilayer structure, we have assessed the viability of device fabrication using ALD (Atomic Layer Deposition) to investigate the correlation between giant permittivity and low dielectric loss in multilayer materials and the film formation process.The results show that the dielectric constant and the leakage current are strongly affected by the oxidizer type and the flow rate during Al2O3 formation. We found that the leakage current was larger when a weak oxidizer was used, so that a strong oxidizer is required, but excessive oxidizing strength results in a low dielectric constant. For TiO2 films, we used EELS (Electron Energy Loss Spectroscopy) to investigate films fabricated using different oxidizers, and by analysis of the oxygen peaks found that there may be differences in the degree of oxygen loss. We are now performing a detailed analysis of both Al2O3 and TiO2 layers formed using different oxidizers.
(1) Wei Lee et al. Appl. Phys. Lett. 96, 162907 (2010)
(2) Geunhee Lee et al. J. Appl. Phys. 114, 027001 (2013)
8:00 PM - ES05.03.10
SnO2 Nanorods Covered by Reduced-Graphene-Oxide Protective Layer for Improved Lithium Storage Capabilities
Christian Carvajal 1 , Sangeeta Rout 1 , Sangram Pradhan 1 , Taliya Gunawansa 1 , Wagneci Hawley 1 , Messaoud Bahoura 1 Show Abstract
1 , Norfolk State University, Portsmouth, Virginia, United States
Lithium-Ion batteries have been impacting energy storage due to their enhanced energy density and cycling life. Combining the emergent field of nanotechnology, lithium-ion batteries can be further improved with semiconductor nanomaterials to increase storage stability. Graphene is a single-layer of carbon atoms arranged in a honeycomb lattice and its variations such as reduced graphene oxide is deemed a soft carbon material capable of Li-ion storage. This study investigates the potential of depositing reduced graphene-oxide (rGO) to cover tin oxide (SnO2) nanorods grown on stainless steel spacer disc substrates by the vapor-liquid-solid technique. Field emission scanning electron microscopy (FESEM) confirmed SnO2 nanorods with a very fine reduced graphene oxide layer on the surface. The assembled coin half-cell battery used rGO/SnO2 nanorods as anode electrode and lithium foil as counter electrode and tested for lithium storage during 70 cycles of charge/discharge in a range of 0.09V to 2.5V. FESEM was used to compare the anode before and after 70 cycle charge-discharge, SnO2 nanorods generated a stable composite of pulverized SnO2 attached to the reduced graphene oxide sheets. The absolute capacity comparison revealed the rGO/SnO2 nanorods battery had a capacity of 800 mAh/g, whereas the previously studied SnO2 nanorods batteries had a capacity of 640 mAh/g. Using a reduced-graphene-oxide protective layer in the Li-ion battery increased the absolute capacity of the SnO2 nanorods and enhanced the performance for Li-ion storage and the results are described in detail.
This work is supported by the NSF-CREST Grant number HRD 1547771.
8:00 PM - ES05.03.11
Effect of Annealing Temperature of Carbon Coated V2O5 Nano-Belts for Energy Applications—Supercapacitors and Electrochromics
Remya Narayanan 1 , Anweshi Dewan 1 Show Abstract
1 , IISER Pune, Pune India
Carbon decorated vanadium pentoxide (C@V2O5) hybrid nanobelts were grown by a single step hydrothermal route with improved electronic conductivity compared to pristine oxide. The hybrid exhibits characteristics suits for supercapacitor and electrochromic window applications. The optimization depending on the annealing temperature of the hybrid material. The C@V2O5 which annealed at 350 oC appears to favor electrochromic applications. The nanobelts at 350 oC exhibits a maximum dynamic transmission modulation as it switched from a yellow to dark green, fast switching response time and highest optical density. The C@V2O5@350 exhibits a transmission modulation of 25 % and 30 % at 620 and 815 nm, which is superior to pristine V2O5, and C@ C@V2O5 at different annealing temperatures based devices. Whereas C@V2O5 @250 oC nanobelt hybrid constitute as an excellent candidate for supercapacitor application. The cumulative effect of conductive carbon and V2O5 with large surface area, delivers a high specific capacitance of 250 F g-1 at 5 Ag-1 which is ~ 78% higher than the pristine V2O5 and ~ 40 % higher than the C@V2O5 unannealed. The C@V2O5 hybrid @ 250 oC showed long term cycle life with capacity retention of ~ 94 % even after 5000 cycles. The obtained results clearly indicates that optimizing the annealing temperature enables the hybrid with application centered characteristics.
8:00 PM - ES05.03.13
Metals Functionalised Carbon Nanotube Composites for Cathode Battery Materials
Poonam Sharma 1 Show Abstract
1 , IIT Jodhpur, Jodhpur India
With advancement in technology and continual change in human life style, the energy consumption rate has accelerated around the world wide. The energy consumption is one of the key factors which indicate the human development. Thus, it’s challenging task to develop sustainable energy source. Although Lithium batteries have been proved best energy source still there are some critical challenges. Out of many challenges, high charge overpotential is one of the obstacles. It affects the rate of charge transfer and slows down battery life. Charge transfer closely depends on cathode morphology means how discharge product distributes on the cathode surface. Here, a series of transition metals (Pt, Pd, Ni, Co & Cu) functionalised carbon nanotubes have been synthesized by wet chemical method followed by annealing. TEM, SEM, TGA, FTIR, and XRD characterizations are favoured metal functionalization on CNT. These materials have been tested as a cathode in Lithium battery and found surprisingly results in overpotential. These cathodes composites also show good stability during discharge–charge cycling.
8:00 PM - ES05.03.15
Thermal Stability of Commercial Lithium-Ion Batteries as a Function of Cathode Chemistry and State of Charge
Heather Barkholtz 1 , Sergei Ivanov 2 , Jill Langendorf 1 , Joshua Lamb 1 , Babu Chalamala 1 , Summer Ferreira 1 Show Abstract
1 , Sandia National Laboratories, Albuquerque, New Mexico, United States, 2 , Los Alamos National Laboratory, Los Alamos, New Mexico, United States
Recently, lithium-ion batteries have developed into a popular technology for transportation and stationary energy storage applications. Extensive lithium-ion battery deployment has dramatically increased awareness of potential safety issues. While thermal runaway behavior of a single lithium-ion battery cell is well studied; how individual cell component materials and their state of charge contribute to thermal runaway is less well known. The work presented here examines material thermal stability as it contributes to whole cell thermal runaway. Material thermal stability was probed using TGA/DSC to decouple anode/cathode contributions to whole cell thermal runaway. Temperature-resolved XRD then defined decomposition pathways corresponding to TGA/DSC data. Finally, we measured the thermal runaway characteristics of several commercial lithium-ion batteries in accelerating rate calorimeter experiments at various states of charge. The cell materials and state of charge were found to have a great influence on thermal runaway onset temperature and maximum cell heating rate. Ultimately, defining these complex thermal decomposition and component interaction reaction mechanisms will increase the predictability of high temperature behavior and with it lithium-ion battery safety.
Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia LLC, a wholly owned subsidiary of Honeywell International Inc. for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525. Sand No.: SAND2017-6316 A.
8:00 PM - ES05.03.16
Modeling the Effect of Aging on the Variation of Thermal Behaviors of a Lithium-Ion Battery During Charge-Discharge Cycling
Boram Koo 1 , Myoungkyou Lee 1 , Jaeshin Yi 1 , Chee-Burm Shin 1 Show Abstract
1 Department of Energy Systems Research, Ajou University, Suwon Korea (the Republic of)
The lithium-ion battery (LIB) is the primary choice for hybrid electric vehicle (HEV) and battery electric vehicle (BEV) applications due to its high energy density, high voltage and low self-discharge rate. The service life of LIB for HEV and BEV applications is generally limited by aging. The aging of LIB depends strongly on the thermal history during usage. In order to secure the resilience of LIB for the HEV and BEV applications, it is essential to develop a modelling tool that has a capability to account for the relationship between the aging and thermal history of LIB to design an optimal battery management system.
In this work, a modeling is performed to predict the effect of aging on the variation of thermal behaviours of an LIB during cycling for a long time. The validation of the modeling approach is provided through the comparison of the modeling results for a 14.6Ah LIB cell from LG Chem. with the experimental measurement data obtained from the cycling tests. The cycling tests were performed under the protocol of the constant-current charge and the constant-current discharge. Model predictions reasonably reproduce the experimental data.
8:00 PM - ES05.03.17
Modeling the Effect of Fast Charge Protocol on the Thermal Behavior of a Lithium-Ion Battery
Myoungkyou Lee 1 , Boram Koo 1 , Jaeshin Yi 1 , Chee-Burm Shin 1 Show Abstract
1 Department of Energy Systems Research, Ajou University, Suwon Korea (the Republic of)
The battery is the primary reason that hampers a mass adoption of electric-drive vehicles (EDVs). Although lithium ion battery (LIB) is a preferred power source for EDV, there is still a plenty of room to be improved for the cost, life and safety of the LIB in EDV applications. Another important issue to be overcome for the EDV battery is searching for an appropriate fast charge protocol to alleviate “range anxiety” for the driver of passenger EDV and thus to enable a rapid growth of EDV market. A short charge time is, however, reported to be achieved always at the expense of cycle life regardless of the charge techniques. It is, therefore, essential to find an optimized fast charge protocol that can balance fast charge and healthy cycling for the LIBs.
In this work, the thermal behaviors of LIB cell under various fast charge protocols are analyzed based on the two-dimensional modeling of the nonuniform temperature distribution in LIB cell during fast charge. The thermal modeling during fast charge is validated by the comparison of the modelling results with the experimental measurements using IR thermal images and thermocouples. The fast charge protocols are evaluated based on the peak temperature of LIB cell and the thermal imbalance within LIB cell during fast charge.
8:00 PM - ES05.03.18
Tuning of Thermal Stability in Layered Li(NixMnyCoz)O2
Tongchao Liu 1 , Jiaxin Zheng 1 , Zongxiang Hu 1 , Feng Pan 1 Show Abstract
1 , Peking University, Shenzhen China
Understanding and further designing new layered Li(NixMnyCoz)O2 (NMC) (x + y + z = 1) materials with optimized thermal stability is important to rechargeable Li batteries (LIBs) for electrical vehicles (EV). Using ab initio calculations combined with experiments, we clarified how the thermal stability of NMC materials can be tuned by the most unstable oxygen, which is determined by the local coordination structure unit (LCSU) of oxygen (TM(Ni, Mn, Co)3-O-Li3−x′): each O atom bonds with three transition metals (TM) from the TM-layer and three to zero Li from fully discharged to charged states from the Li-layer. Under this model, how the lithium content, valence states of Ni, contents of Ni, Mn, and Co, and Ni/Li disorder to tune the thermal stability of NMC materials by affecting the sites, content, and the release temperature of the most unstable oxygen is proposed. The synergistic affect between Li vacancies and raised valence state of Ni during delithiation process can aggravate instability of oxygen, and oxygen coordinated with more nickel (especially with high valence state) in LSCU becomes more unstable at a fixed delithiation state. The Ni/Li mixing would decrease the thermal stability of the “Ni=Mn” group NMC materials but benefit the thermal stability of “Ni-rich” group, because the Ni in the Li layer would form 180° Ni−O−Ni super exchange chains in “Ni-rich” NMC materials. Mn and Co doping can tune the initial valence state of Ni, local coordination environment of oxygen, and the Ni/Li disorder, thus to tune the thermal stability directly.
8:00 PM - ES05.03.19
Aluminum-Air Batteries with High Output Voltages
Sangjin Choi 1 , Daehee Lee 1 , Gwangmook Kim 1 , Yoon Yun Lee 1 , Bokyung Kim 1 , Jooho Moon 1 , Wooyoung Shim 1 Show Abstract
1 , Yonsei University, Seoul Korea (the Republic of)
The battery shape is critical limiting factor affecting foreseeable energy storage applications. In particular, deformable metal-air battery systems could offer a low cost, low flammability, and high capacity, but the fabrication of such metal–air batteries remains challenging. Here, we show that a shape-reconfigurable materials approach, in which the deformable components composed of micro- and nanoscale composites are assembled, is suitable for constructing polymorphic metal-air batteries. We adopt an aluminum-air battery cell as an ideal platform, which involves three-electron transfer during charging reactions; as a result, it provides a specific capacity that rivals that of a single-electron lithium-ion battery. This cell is a great platform to test a shape-reconfigurable design because of easier handling, greater safety, and lower reactivity. This architecture is simple and scalable and also addresses the fundamental limitations of aluminum-air batteries by allowing the use of deformable packing designs to increase the performance output. Further, this approach is technologically unique in that it a method that enables the realization of a 3D shape change, which has never been observed for aluminum–air batteries. This significant deformability results in a specific capacity of 128 mAh/g per cell; calculated from the total mass of anode (496 mAh/g per cell; based on the mass of consumed aluminum), and a high output voltage (10.3 V) with 16 unit battery cells connected in series. The resulting battery can endure significant geometrical distortion such as three-dimensional stretching and twisting while the electrochemical performance is preserved. This work represents an advancement in deformable aluminum–air batteries using the shape-reconfigurable materials concept, thus establishing a paradigm for shape-reconfigurable batteries with exceptional mechanical functionalities.
8:00 PM - ES05.03.20
Delineating the Role of PbO2 Nanoparticle Size in Aging for Lead Acid Battery
Sooun Lee 1 , Dana Jin 1 , Wooyoung Shim 1 Show Abstract
1 , Yonsei University, Seoul Korea (the Republic of)
Among the various types of energy storage devices, the lead-acid battery is the one of the oldest rechargeable batteries, but it is still widely used because it is cheaper than newer technologies and has high power-to-weight ratio. This feature makes lead-acid batteries attractive for use in advanced automobile systems, such as heating, cooling, navigation, and other electrical components that increase electrical energy consumption. However, its low charge efficiency of ~50% limits the cycle life of the battery. This has led to extensive studies into the aging mechanism with a view to enhancing the charge efficiency. Sulfation is a major cause of aging in the lead-acid battery, which is partially reconverted back to an electrochemically active form resulting in a corresponding loss of capacity.
We herein report a nanoparticle strategy at tens of nanometers length scale that can enhance the reversible phase transformation from PbSO4 to PbO2 upon charging, thus potentially extending the lifetime of these batteries. Our combined theoretical and experimental studies suggest that control over the size of PbO2 nanoparticles is critical to the aging mechanism. PbO2 nanoparticles of ~ 100 nm in diameter suppressing sulfation, which leads to a reversible phase transformation from PbSO4 to PbO2. In addition, PbO2 nanoparticles (100 nm in diameter) can provide a greater robustness in the context of shedding of the active materials from the positive grid. These results suggest that lead-acid batteries can be operated with an extended lifetime partly by addressing the intrinsic aging issues associated with irreversible sulfation. This approach addresses one of the significant challenges for realizing a high cycle life, while improving the mechanical stability and shedding, which are also correlated to battery life.
8:00 PM - ES05.03.21
Biomimetic Supraparticles for Battery
Luiz Gorup 2 1 , Emerson Camargo 1 , Siu On Tung 2 , Gleiciani de Queiros Silveira 2 , Naomi Ramesar 2 , Nicholas Kotov 2 Show Abstract
2 Chemical Engineering, University of Michigan–Ann Arbor, Ann Arbor, Michigan, United States, 1 , Federal University of Sao Carlos , Sao Carlos Brazil
Biomimetic systems can be used as a template that enables innovative alternatives to overcome the limitations of conventional synthesis methods.
In this work, we use biotechnology with materials chemistry to fabricate self-organized systems of erdite nanoparticles to form pollen-shaped supraparticles (SPs).
The use of erdite NaFeS2-2H2O supraparticles as the cathode in a rechargeable sodium battery system is very intriguing due to the following reasons: First, it is inexpensive since iron is an abundant metal element in earth’s crust.
A second important property of supraparticles is its ability to self-assemble nanometric particles into organized micrometric structure. Leading to enhanced cathode performance due to profoundly sensitive deviations from the crystalline perfection. Among them are grain boundaries that play an important role on battery performance by changing the ions distribution inside particles and corresponding stress level change.
Another reason is that metal sulfide instead of transition metal oxide as cathode material for sodium battery is due to the strong coulombic effect and the energy barrier of iron ions transportation in the crystal structure is very high. Sulfide has a much lower electronegativity than oxide, which makes transition metal sulfide a very promising cathode candidate for rechargeable sodium battery.
Hu et. al. 2015 showed than after conversion of FeS2 microparticles in layer-structured NaxFeS2 was formed during cycling it was possible to obtain high-rate capability and unprecedented long-term cyclability
In this work we demonstrate that erdite supraparticles can be applied in room-temperature rechargeable sodium batteries with only the intercalation reaction by simultaneously selecting a compatible NaSO3CF3/diglyme electrolyte and tuning the cut-off voltage to 0.8 V. A high-rate capability (120 mAh/g at 54 mA/g) and long-term cyclability (95% capacity retention for 100 cycles) has been obtained. This shows that the production of rechargeable sodium batteries with NaFeS2-2H2O supraparticles is viable for commercial utilization
8:00 PM - ES05.03.22
A Novel, Highly Efficient Electrode Material for Supercapacitors and Lithium-Ion Batteries from Biomass
Anjon Mondal 1 , Katja Kretschmer 2 , Hao Liu 2 , Guoxiu Wang 2 , Francesca Iacopi 1 Show Abstract
1 Integrated Nano Systems Laboratory, Faculty of Engineering and Information Technology, University of Technology, Sydney, New South Wales, Australia, 2 Centre for Clean Energy Technology, Faculty of Science, University of Technology, Sydney, New South Wales, Australia
A simple, cost-effective and one-step activation method was employed to synthesize nitrogen-containing porous carbon using banana peel waste as the biomass precursor and common food additive KHCO3 as an activating agent. Structural characterization shows that the as-obtained carbon comprised of abundant interconnected pores has a high specific surface area of 2166 m2 g-1. When applied as electrode material for supercapacitors, the porous carbon shows a high specific capacitance of 366 F g-1 and 110 F g-1 at the current density of 0.5 A g-1 in aqueous (1 M H2SO4) and organic electrolytes (1 M LiClO4), respectively. This carbon also displayed excellent capacitance retention of 92 % over 10, 000 cycles in aqueous electrolyte and 93 % after 5,000 cycles in organic electrolyte, which outperforms most previously reported carbon materials. Serving as anode material for lithium ion batteries, such porous carbon delivered a specific capacity of 748 mA h g-1 at the current density of 100 mA g-1. The superior electrochemical performances of this carbon electrode for both supercapacitors and lithium ion batteries are due to its high specific surface area, unique porous structure, and the naturally occurring nitrogen doping effect. The one-step synthesis technique we developed here also signifies an attractive methodology for large-scale production of porous carbon from different biomass sources for not only the energy storage field but also other diverse applications.
8:00 PM - ES05.03.23
Extensively Interconnected Silicon-Carbon Nanocomposite Derived from Ultrathin Cellulose Nanofibers for High-Performance Lithium-Ion Battery Anode
Jong Min Kim 1 , Yuanzhe Piao 1 Show Abstract
1 Graduate School of Convergence Science and Technology, Seoul National University, Suwon Korea (the Republic of)
Silicon is one of the most anticipated alternatives for the conventional graphite anode due to its high specific capacity (3579 mAh g-1) and natural abundance. However, it suffers from the severe volume change during charge/discharge, which results in the poor cycling performance. Thus, we prepare extensively interconnected silicon-carbon nanocomposite derived from ultrathin cellulose nanofibers. Carbon network from ultrathin cellulose nanofibers holds silicon nanoparticles tightly and interconnects them so that silicon nanoparticles can endure the volume change and have the efficient electron path to give good cycle stability and good rate performance. As a result, it exhibits a reversible capacity of 808 mAh g-1 which is a capacity retention of 72.2 % after 500 cycles. Additionally, it shows a reversible capacity of 464 mAh g-1 at a high current density of 8 A g-1. By simple mixing of silicon nanoparticles and ultrathin cellulose nanofibers in aqueous solution, silicon-ultrathin cellulose nanofibers composite can be formed due to hydrogen bonding between the carboxylic group of cellulose nanofiber and a native oxide layer of silicon nanoparticle. After pyrolysis, cellulose nanofibers convert into carbon. Interestingly, this structure prevents the brittle electrode formation with a water-based binder during slurry drying. Therefore, this material has a potential to be utilized in practical use.
8:00 PM - ES05.03.24
A Highly Soluble, Two-Electron Donor for Non-Aqueous Redox Flow Batteries
Nuwan Harsha Attanayake 2 , Jeffrey Kowalski 1 , Jarrod Milshtein 1 , Aman Preet Kaur 2 , Matthew Casselman 2 , Sean Parkin 2 , Chad Risko 2 , Fikile Brushett 1 , Susan Odom 2 Show Abstract
2 , University of Kentucky, Lexington, Kentucky, United States, 1 , Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
Redox flow batteries (RFBs) are a promising candidate for stationary energy storage applications due to their decoupled energy and power, long service life, and simple manufacturing 1-2. Despite advances in RFBs with aqueous electrolytes, widespread adoption is limited. In addition to safety concerns of highly acidic and/or corrosive electrolytes, the cell voltages of aqueous-based RFBs are limited due to the electrochemical window of water (1.5 V). Transitioning from aqueous to non-aqueous electrolytes offers a wider and stable electrochemical window (>4 V), a greater selection of redox materials, a wider range of working temperatures, higher cell voltage, and – possibly – higher energy density. To date, a limited number of organic compounds have been evaluated as active materials for non-aqueous RFB applications 3-4. Among them, most of the molecules are only stable at their neutral and single oxidized (radical cation) state. Engineering stable, highly soluble two electron-donating active materials would lead to higher capacity catholytes for non aqueous RFBs. From our previous work, we found that phenothiazine can be functionalized to produce a more stable dication by introducing methoxy groups at 3,7 positions of N-ethylphenothiazine (EPT). However, the limited solubility of N-ethyl-3,7-dimethoxyphenothiazine (DMeOEPT, 0.06 M in Acetonitrile) limits the practical applications of this donor. To raise active materials’ concentration and thus solution capacity, we designed new two-electron donors based on phenothiazines containing oligoglycol chains. This presentation will report the preparation and characterization of new two-electron donors, with solubilities as high as 0.5 M in all relevant oxidation states (neutral, radical cation, dication), which we achieved by introducing oligoglycol chains at 3 and 7 positions of parent compound N-ethylphenothiazine.
1. Alotto, Piergiorgio, Massimo Guarnieri, and Federico Moro. "Redox Flow Batteries for the Storage of Renewable Energy: A Review." Renewable and Sustainable Energy Revi., 29 (2014): 325-35.
2 .Kaur, Aman Preet, et al. "A Highly Soluble Organic Catholyte for Non Aqueous Redox Flow Batteries." Energy Technology 3.5 (2015): 476-80.
3. Milshtein, Jarrod D, et al. "4-Acetamido-2, 2, 6, 6-Tetramethylpiperidine-1-Oxyl as a Model Organic Redox Active Compound for Nonaqueous Flow Batteries." J. Power Sources 327 (2016): 151-59.
4. Milshtein, Jarrod D, et al. "High Current Density, Long Duration Cycling of Soluble Organic Active Species for Non-Aqueous Redox Flow Batteries." Energy & Envirol Sci., 9.11 (2016): 3531-43.
8:00 PM - ES05.03.25
Transformation of Bulk Alloys to Oxide Nanowires and Their Use in a Li-Ion Battery Separator
Oleksandr Magazynskyy 1 , Danni Lei 1 , Jim Benson 1 , Gene Berdichevsky 2 , Benjamin Zusmann 1 , Kostiantyn Turcheniuk 1 , Gleb Yushin 1 Show Abstract
1 MSE, Georgia Institute of Technology, Atlanta, Georgia, United States, 2 , Sila Nanotechnologies Inc, Alamed, California, United States
One dimensional (1D) nanostructures offer prospects for enhancing electrical, thermal and mechanical properties of a broad range of functional materials and composites, but their synthesis methods, such as catalyst-assisted vapor deposition, physical vapor deposition, hydrothermal synthesis, the use of sacrificial templates and others, are relatively expensive and difficult to scale. Here we demonstrate direct transformation of bulk materials into nanowires at room temperature and ambient pressure without use of catalysts, corrosive or toxic chemicals, or any external stimuli . The nanowire formation proceeds via a minimization of the strain energy at the boundary of chemical transformation reaction front. We show transformation of multi-micron particles of Al alloy and Mg alloy into alkoxide nanowires of tunable dimensions, which are converted into oxide nanowires upon simple heating in air. The reported approach provides opportunities for ultra-low cost large-scale synthesis of 1D materials and membranes. Conventional polymer separators for Li-ion batteries (LIBs) suffer from limited mechanical strength and low thermal stability, which may lead to thermal runaway and cell explosion. We produced flexible, binder-free, nonwoven fabric composed of gamma-Al2O3 nanowires, using a simple tape casting technique followed by a heat treatment in air. The overall morphology of the produced fabric is somewhat similar to that of a paper, where the cellulose fibers are replaced with stronger and stiffer Al2O3 nanowires. Owing to the fibrous nature of thus-produced free-standing films and the small diameter of the Al2O3 nanowires, they exhibit good flexibility. This is in contrast to anodized Al2O3 membranes of comparable thickness that are known to be extremely brittle and difficult to handle. Results of electrolyte wetting tests revealed significantly superior performance of Al2O3 paper compared to commonly used commercial olefin (polypropylene) separator or a cellulose fiber separator. The wetting rate of the Al2O3 separator is significantly higher owing to its polar nature, as determined by both the final wetting area and the speed of wetting. Thermal stability tests demonstrate the advantage of having a flexible porous ceramic separator with operating temperatures above 800°C, which is important because of rapid heating to high temperatures that may occur in failing LIBs. In contrast, the most commonly used olefin separators typically start melting at around 120°C and oxidize at around 300°C. Finally, the strength of ceramic fibers is known to exceed that of the olefins, which should allow formation of thinner separators in automotive LIBs without sacrifice of their mechanical properties.
. D Lei, J Benson, A Magasinski, G Berdichevsky, G Yushin, Transformation of bulk alloys to oxide nanowires, Science 2017, 355 (6322), 267-271.
8:00 PM - ES05.03.26
Improved Cathode/Electrolyte Interfaces in All-Solid-State Batteries
Fudong Han 1 , Jie Yue 1 , Chunsheng Wang 1 Show Abstract
1 , University of Maryland, College Park, Maryland, United States
The exact sources of the high interfacial resistance between solid electrolyte and cathode have not been fully understood. Here we show the electrochemical decomposition of solid electrolyte itself, and/or the electrochemical reaction between solid electrolyte and electrode may lead to large interfacial resistances which have been ignored based on the “overestimated” electrochemical stability of solid electrolytes. A superior cathode/electrolyte interface could only be achieved if one could improve the electrochemical stability as well as the interfacial contact, chemical stability, mechanical stability, and space-charge-layer suppression capability simultaneously, although the exact contribution of each source is highly system-dependent. We then will present one example of lowering the interfacial resistance between Li7La3Zr2O12 solid electrolyte and LiCoO2 cathode by engineering the interphase. The interphase engineering approach enabled an all-ceramic Li/Li7La3Zr2O12/LiCoO2 cell to deliver a significantly-improved cycling and rate performance at both room and elevated temperatures.
Summer Ferreira, Sandia National Laboratories
Judy Jeevarajan, Underwriters Laboratories Inc.
Hiroyuki Kubo, National Institute of Technology and Evaluation
Brittany Westlake, Electric Power Research Institute
ES05.04: Novel Materials Beyond Lithium-Ion II
Thursday AM, November 30, 2017
Hynes, Level 3, Room 309
8:00 AM - ES05.04.01
Assemble of Energy Storage Device Based on the Nano-Structured Materials and the Electrochemical Performance
Yan Wang 1 , Zexiang Chen 1 , Xinyu Yan 1 , Hai Li 1 , Jijun Zhang 1 Show Abstract
1 School of Optoelectronic Information, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
Transition metal compound is favorable for reversible faradaic reactions enabling high electrochemical performance due to the unique nano-structure desigin and construction. However, the rather low conductivity, easily agglomeration and large shrinkage of the nano-structure limited the actual electrochemical performance greatly. To overcome this drawback and improve the electrochemical performance of materials, a composite material which incorporates Fe2O3 on the graphene conductive support has been proposed as the anode material, and hollow NiCo2S4 has been considered as cathode material. Especially, the hierarchical structureed hollow NiCo2S4 was compose of nanosheets which enables the close contact between the material and electrolyte, as a result, offering higher electrochemical activity. The new findings of our work: 1) Firstly proposed a scalable fabrication of a hollow NiCo2S4 spheres in which a hierarchical NiCo2S4 nano-flakes grown on SiO2 hard template by a hydrothermal method to form a core-shell 3D nano-structure. 2) For the anode material, graphene provides a backbone and serves as a high surface area to support for a uniform growth of uniform Fe2O3 particles. 3) The assembled energy storage device consisting of hollow NiCo2S4 microspheres as positive electrode, rGO/Fe2O3 composite as negative electrode reaches high power density of 22 kW/kg and long cycle life of 90% retention after 1000 cycles at the current density of 1 A/g. 4) The environmentally friendly hydrothermal method is suitable for industrial production. Moreover, the rational design provides a blueprint for a cheap synthesis of a three-dimensional nano-structure.
8:15 AM - ES05.04.02
Designing Stable, Soluble Organic Electro-Active Materials for Non-Aqueous Flow Batteries
Susan Odom 1 , Aman Preet Kaur 1 , Matthew Casselman 1 , Nuwan Harsha Attanayake 1 , Corrine Elliott 1 , Jarrod Milshtein 2 , Jeffrey Kowalski 2 , Sean Parkin 1 , John Anthony 1 , Chad Risko 1 , Fikile Brushett 2 Show Abstract
1 , University of Kentucky , Lexington, Kentucky, United States, 2 , Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
Redox flow batteries (RFBs) are promising candidates for grid storage, with a few large-scale systems currently in operation. However, current systems have not met the stringent cost and/or safety requirements needed for widespread implementation. Replacing vanadium with organic compounds may lower materials costs, and utilizing non-aqueous (aprotic) electrolyte solvents, in place of water, could enable a 2- to 3-fold increase in operating voltage. Both features make non-aqueous RFBs candidates for large-scale stationary storage. A limited number of organic compounds have been reported as stable electron donors and acceptors, with even fewer materials being studied as small-molecule two-electron donors and/or two-electron acceptors. Our recent efforts have focused on the development of highly soluble electron donors and acceptors with stable oxidized and reduced states. This presentation will focus on design strategies utilized to increase solubility as well as molecular stability in all relevant states of charge. In particular, we highlight the design, synthesis, and electrochemical analysis of phenothiazine and naphthoquinone derivatives. We show that tactical placement of substituents leads to improved stability of doubly oxidized and doubly reduced species, whilst retaining atom economy and high solubility.
8:30 AM - ES05.04.03
Flexible/Shape-Conformable, Bipolar All-Solid-State Lithium-Ion Batteries Prepared by Multistage Printing
Se-Hee Kim 1 , Sang-Young Lee 1 Show Abstract
1 , UNIST, Ulsan Korea (the Republic of)
Bipolar all-solid-state lithium-ion batteries (LIBs) have attracted considerable attention as a promising approach to address the ever-increasing demand for high energy and safety. However, the use of (sulfide- or oxide-based) inorganic solid electrolytes, which have been the most extensively investigated electrolytes in LIBs, causes problems with respect to mechanical flexibility and form factors in addition to their longstanding issues such as chemical/electrochemical instability, interfacial contact resistance and manufacturing processability. Here, we develop a new class of flexible/shape-versatile bipolar all-solid-state LIBs via ultraviolet (UV) curing-assisted multistage printing, which does not require the high-pressure/high-temperature sintering processes adopted for typical inorganic electrolyte-based all-solid-state LIBs. Instead of inorganic electrolytes, a flexible/nonflammable gel electrolyte consisting of a sebaconitrile-based electrolyte and a semi-interpenetrating polymer network skeleton is used as a core element in the printed electrodes and gel composite electrolytes (GCEs, acting as an ion-conducting separator membrane). Rheology tuning (toward thixotropic fluid behavior) of the electrode and GCE pastes, in conjunction with solvent-drying-free multistage printing, enables the monolithic integration of in-series/in-plane bipolar-stacked cells onto complex-shaped objects. Because of the aforementioned material and process novelties, the printed bipolar LIBs show exceptional flexibility, form factors, charge/discharge behavior and abuse tolerance (nonflammability) that far exceed those achievable with inorganic-electrolyte-based conventional bipolar cell technologies.
8:45 AM - ES05.04.04
Ambient Temperature Aqueous Sulfur Batteries for Ultralow Cost Grid Storage
Liang Su 1 , Zheng Li 2 1 , Menghsuan Pan 1 , Ping-Chun Tsai 1 , Joseph Valle 1 , Andres Badel 1 , Stephanie Eiler 1 , Kai Xiang 1 , Fikile Brushett 1 , Yet-Ming Chiang 1 Show Abstract
1 , Massachusetts Institute of Technology, Cambridge, Massachusetts, United States, 2 , Virginia Tech, Blacksburg, Virginia, United States
Sulfur is an attractive reactant for such concepts due to its exceptionally low cost, high natural abundance, and high specific and volumetric capacity owing to its two-electron reaction. Taking the cost-per-capacity (e.g., in US$/Ah) as a metric, sulfur has the lowest cost of any known electrode-active compound with the exception of water and air. However, in order to take advantage of sulfur’s low-cost potential, all other components must also have low cost.
Towards enabling ultralow cost grid storage, we demonstrate an ambient-temperature aqueous rechargeable flow battery that uses low-cost polysulfide chemistry in conjunction with lithium or sodium as the working ion, and an air-breathing cathode. Four different laboratory cell constructions are used to test the half-cell and full-cell reactions, including a pumped air-breathing cell that exhibits stable room-temperature cycling over 960h with a lithium polysulfide anolyte and dissolved lithium sulfate catholyte. In this approach the solution energy density is 30-150 Wh/L, which exceeds current solution-based flow batteries, and the chemical cost of stored energy is exceptionally low, especially when using sodium polysulfide (~1 US$/kWh). Results of techno-economic modeling are also presented, which show that when projected to full system-level, this new approach has energy and power costs that are comparable to those of pumped hydroelectric storage (PHS) and underground compressed air energy storage (CAES), but without their geographical and environmental constraints.
This work was supported as part of the Joint Center for Energy Storage Research, an Energy Innovation Hub funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences.
9:00 AM - ES05.04.05
Electrochemical Cycling Behavior of Aqueous Polysulfide within and beyond the Solubility Limit
Menghsuan Pan 1 , Liang Su 1 , Linda Jing 1 , Stephanie Eiler 1 , Yet-Ming Chiang 1 Show Abstract
1 , Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
The low cost, high solubility, and high specific capacity of aqueous polysulfide electrodes are attractive for several potential battery applications. These include a redox flow battery recently developed in our group that pairs an air (oxygen) cathode with an aqueous polysulfide anode, and which may be especially attractive for low-cost large scale grid storage. However, the speciation and stability of polysulfides in alkaline aqueous solution are complex due to the large number of species involved in the chemical equilibria. Here, we investigate the electrochemical stability of aqueous polysulfide solutions as a function of speciation range for two different working ions – lithium or sodium. Stability over 1000 hours of cycling with negligible capacity fade is demonstrated under optimized conditions. For nickel electrodes, the overpotential is found to be as low as 50 mV. These findings pave the way for use of aqueous polysulfides in large scale energy storage applications.
A strategy to further decreasing cost is to increase the capacity of the redox active solution. The solubility of aqueous polysulfides in their reduced form at room temperature is ~5 M sulfur, equivalent to 67 Ah/L. One way to overcome this limitation is to reduce the alkali polysulfides to the solid state, and to re-dissolve the precipitate during oxidation. We show ~60% increase in reversible capacity over the solution alone, using this approach. Long-term galvanostatic cycling is further used to characterize stability over wide speciation ranges.
This work was supported as part of the Joint Center for Energy Storage Research, an Energy Innovation Hub funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences.
9:15 AM - ES05.04.06
Harnessing Strain to Raise Oxidation Potentials in Organic Electroactive Materials
Nuwan Harsha Attanayake 1 , Corrine Elliott 1 , Matthew Casselman 1 , Sean Parkin 1 , Chad Risko 1 , Susan Odom 1 Show Abstract
1 , University of Kentucky, Lexington, Kentucky, United States
Designing robust, high voltage electroactive organic materials is important for redox shuttles utilized in overcharge protection in lithium-ion batteries and as active materials in non-aqueous redox flow batteries. The conventional routine to controlling redox potentials is to incorporate electron-donating and/or electron-withdrawing groups onto p conjugated organic molecules, making use of the well-known Hammett constants as predictors of the extent of the change of redox potentials 1. Recently, we found that the substitution of sterically bulk groups at strategic positions of the phenothiazine derivatives raises oxidation potentials by preventing relaxation events in the radical cation form, which is unique from incorporating substituents in π-conjugated networks are strained in both the ground (neutral) and ionized (oxidized or reduced) electronic states 2. Here we sought to design higher oxidation potential phenothiazine derivatives by combining steric effects and utilizing electron withdrawing groups at precise locations along the phenothiazine ring system. This presentation focuses on this new approach to raise the oxidation potential in phenothiazine derivatives, including molecular designing strategies, synthetic routes, density functional calculations, electrochemical analysis, and stability studies.
1. Hammett, Louis P. "The Effect of Structure Upon the Reactions of Organic Compounds. Benzene Derivatives." J. Am. Chem. Soc. 59.1 (1937): 96-103.
2. Casselman, Matthew D, et al. "Beyond the Hammett Effect: Using Strain to Alter the Landscape of Electrochemical Potentials." ChemPhysChem (2017).
ES05.05: Separators and Electrolytes
Thursday AM, November 30, 2017
Hynes, Level 3, Room 309
10:00 AM - *ES05.05.01
Towards Safer Batteries and Capacitors by a Multifunctional Materials Approach
Jodie Lutkenhaus 1 , Dimitris Lagoudas 1 , James Boyd 1 , Micah Green 1 , Haleh Ardebili 2 , Rafael Verduzco 3 Show Abstract
1 , Texas A&M University, College Station, Texas, United States, 2 , University of Houston, Houston, Texas, United States, 3 , Rice University, Houston, Texas, United States
Materials for batteries and capacitors are primarily selected for their ability to store electrochemical energy. Yet as energy storage is pressed toward higher voltages and energies, or as electrochemical cells are packed into smaller and denser packages, the boundary between safe and unsafe is approached. Several high-profile battery failures highlight this issue. We propose that one way to enhance safety is through improved mechanical properties at the materials level by a multifunctional approach. Currently, the external packaging of a cell provides mechanical integrity and protection, such that the mechanical properties of the electrode and electrolyte are often overlooked. If the electrode and electrolyte materials could be imparted with exceptional mechanical properties (such as strength and toughness), then safety may be enhanced. In a hypothetical sense, one might envision a structural battery or capacitor that can bear extreme mechanical loads – or even bulletproof batteries that absorb mechanical energy from impact. Towards, this we present on Kevlar-enhanced capacitors and super-tough battery electrodes. The unifying theme is that the properties of an active electrode material may be augmented through the addition of a polymer that enhances the electrode’s mechanical properties. In the first case, Kevlar is known for its high modulus and toughness; from Kevlar, we synthesize aramid nanofibers for incorporation into graphene-based supercapacitor electrodes. This results in an enhancement in electrode modulus and strength. In the second case, V2O5 is a high capacity cathode material that can undergo volume expansion and pulverization; we use an electron- and ion-conducting polymer binder to stop pulverization and simultaneously enhance the toughness. The biggest challenge in this general approach is balancing the mechanical properties with the ability to store energy, while maintaining long term stability.
10:30 AM - ES05.05.02
Surface-Tethered Polymer Brushes for Safe Lithium Battery Electrolytes
Brian Shen 1 , Wyatt Tenhaeff 1 Show Abstract
1 , University of Rochester, Rochester, New York, United States
As the energy density of lithium ion batteries increases so do consumer safety concerns, especially over flammability of lithium ion batteries in electric vehicles. We seek to enable impact-safe electrolytes by exploiting surface-initiated atom transfer radical polymerization (SI-ATRP) to graft polymer brushes to the surface of ceramic and glass particles.
One approach is the development of non-Newtonian, shear-thickening electrolytes (STE), which are fluids, the viscosity of which increases with external shear. In this work, we prepare STEs composed of silica nanoparticles (SiO2-NP) in standard lithium ion battery electrolytes (e.g. 1.2M LiPF6 in EC/DMC). Under low shear conditions, these electrolytes flow and can be introduced into conventional lithium ion cells. With the correct SiO2-NP diameters and weight loading, STEs undergo a rapid, reversible transition to solid-like viscosities upon application of external shear, improving safety during a collision. However, untreated SiO2-NP in suspension can agglomerate and settle out of the solution. Thus, over long calendar times, the electrolyte could fail to exhibit dilatant behavior in the event of a collision. In this work, we address sedimentation by covalently grafting poly(methyl methacrylate) (PMMA) brushes to the SiO2-NP using SI-ATRP to sterically stabilize the particles. SiO2-NP (250 nm diameter) were functionalized with PMMA brushes grown to 40 nm, confirmed by Fourier transform infrared and X-ray photoelectron spectroscopy. STEs were composed of SiO2-NP in propylene carbonate (PC). Non-Newtonian behavior was observed at >15 wt% SiO2-NP (treated or untreated) in PC. Neutron scattering revealed the average radius of untreated SiO2-NP aggregates in PC at rest was 5060 ±70 Å, and 4034 ± 125 Å for treated SiO2-NP aggregates. For STEs consisting of 35 wt% SiO2-NP in 1.0M LiPF6 in PC, it was observed that the conductivity decreased from 2.2 mS/cm to 0.4 mS/cm upon shearing.
10:45 AM - ES05.05.03
Abuse Tolerant Ionic Liquid Electrolytes
Gabriel Torres 1 , Aditya Raghunathan 1 , Surya Moganty 1 Show Abstract
1 , NOHMs Technologies, Rochester, New York, United States
NOHMs Technologies is developing functional ionic liquid based hybrid electrolytes for high energy density, high voltage, and high power batteries for mobility and consumer applications. It is well established that the composition of electrolytes greatly affects cell performance from rate capability, lithium cycling efficiency, and capacity retention at various temperatures to tolerance against electrical, mechanical, and thermal abuses. Ionic liquids offer a host of attractive properties for electrolytes, including ultralow vapor pressure, high thermal stability, high ionic conductivity, and wide electrochemical stability. However, there are some physical property limitations that to-date has made them unattractive for lithium battery applications. High viscosity and the fraction of the ionic conductivity of the electrolyte arising from mobile lithium ions (i.e. the so-called lithium transference numbers) are typically low for these materials, which make cells assembled using ionic liquid electrolytes prone to large polarization during operation of the cell.
These limitations can be easily overcome by blending functional ionic liquids with appropriate co-solvents. These hybrid electrolytes simultaneously overcome the poor thermal & electrochemical stability and safety problems that have plagued lithium battery electrolytes for years while still maintaining high conductivity. They provide a platform for engineering electrolytes with both chemical and interfacial tunability that beyond improving safety, expand the range of available battery form factors.
We will discuss the following: 1) how functional ionic liquid and co-solvent formulations impact SEI formation and voltage stability, 2) the relationship of capacity fade and operating temperature; and 3) how electrolyte formulations improve the abuse tolerance of pouch cells.
11:00 AM - ES05.05.04
Raising the Oxidation Potentials of Phenothiazines to Advance Redox Shuttle Performance
Chad Risko 1 Show Abstract
1 , University of Kentucky, Lexington, Kentucky, United States
As additives in electrolyte formulations, molecular redox shuttles offer opportunities to increase lifetimes and mitigate safety concerns of lithium-ion batteries by preventing overcharge. Redox shuttles act to alleviate overcharge by (i) undergoing oxidation at the cathode when the cell potential reaches the molecular oxidation potential, (ii) diffusing through the electrolyte in the oxidized state, (iii) reducing back to the neutral form through reduction at the anode, and (iv) diffusing through the electrolyte back to the cathode in the neutral state, where the molecule can then repeat the sequence. For new generations of high-potential cathodes, it is critical that redox shuttles are able to be oxidized at ever higher potentials while maintaining their favorable reduction potentials. From the standpoint of redox-shuttle design, however, this is a difficult standard as donor or acceptor substituents typically added to redox-shuttle frameworks tend to simultaneously alter both the oxidation and reduction potentials. Here we present a theoretical investigation, supported by synthesis and experiment, that demonstrates how steric strain can be used as a principle to overcome substituent electronic considerations cast in terms of Hammett constants. Focusing on phenothiazines, which show great promise as redox shuttles in lithium-ion battery applications, we are able to separate substituent electronic and steric effects, and offer new strategies to design novel redox shuttles.
11:15 AM - ES05.05.05
Application of Smart Membrane Separators in Li-Ion Batteries for Controllable Ion Transport
Travis Hery 1 , Vishnu Sundaresan 1 Show Abstract
1 Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, Ohio, United States
We have created a smart membrane separator with a tunable through-membrane ionic conductivity. This membrane, when used in a battery, is able to turn on and off the flow of ions between the battery electrodes. Having an internal ion flow controller within a battery is critical to preventing thermal runaway events, minimizing self-discharge, and optimizing ion transport for various operating conditions. The smart membrane separator could lead to novel electrochemical architectures. It can also be directly incorporated into existing technologies, such as a lithium ion battery.
Lithium ion batteries currently provide the highest energy density among commercially available technologies. They also have a high coulombic efficiency, are able to maintain an energy level with little self-discharge, and retain most of their capacity even after thousands of cycles. However, lithium ion batteries are a safety hazard at elevated temperatures, experiencing thermal runaway events resulting in fires or explosions. A thermal runaway event cannot be stopped with electronic controls once it has begun. In order to prevent a thermal runaway event from proceeding, it is required to have an internal control mechanism for ion transport. There are passive ways to control ion flow, such as a shutdown separator which has an internal layer that soften at elevated temperatures, closing the pores and prevent ion transport. It is also possible to mitigate the consequences of thermal runaway via a flame suppressant added to the electrolyte. Both these methods do increase the safety of lithium ion batteries, but are terminal to battery operation upon the onset of thermal runaway and the battery must be replaced.
Here we propose the use of a membrane with tunable ionic conductivity to be used as the separator in a lithium ion battery that has real time control of ion transport. With this technology, ion flow can be minimized by decreasing conductivity in order to prevent a thermal runaway event. Once battery temperatures return to a safe level, conductivity can be increased and battery operation can continue. The smart membrane separator is comprised of the redox active conducting polymer dodecylbenzenesulfonate-doped polypyrrole (PPy(DBS)) electropolymerized onto a porous substrate. The polymer, when in an oxidized state, is tightly compacted and does not allow ions to flow through, resulting in a low conductivity. Upon reduction, ions flood the backbone of the polymer to achieve electroneutrality and subsequently provide hopping sites for ion travel, resulting in high conductivity. The area-specific conductance of the membrane for the polymer reduced and oxidized states are 462 µS/cm2 and 78 µS/cm2, respectively, giving an amplification factor of 5.897. The smart membrane separator ionic conductivity can therefore be tuned as a function of the polymer redox state and used for controlled ion transport within a lithium ion battery.
ES05.06: Anode and Cathode Materials
Thursday PM, November 30, 2017
Hynes, Level 3, Room 309
1:30 PM - *ES05.06.01
Next Generation Flexible and Stretchable Batteries Based on Solid Polymer Electrolytes
Haleh Ardebili 1 Show Abstract
1 Department of Mechanical Engineering, University of Houston, Houston, Texas, United States
The safety of flexible and stretchable batteries is a critical objective due to the intimate interaction of such devices with human organs such as batteries that are integrated with touch-screens or embedded in clothing. To enhance safety in batteries, we can replace the flammable liquid organic electrolyte with a more thermally and chemically stable solid electrolyte. Here, we present the fabrication and testing of a high performance thin-film Li-ion battery (LIB) that is both flexible and relatively safer compared to the conventional liquid electrolyte based batteries. The concept is facilitated by the use of solid polymer nanocomposite electrolyte, specifically, composed of polyethylene oxide (PEO) matrix and 1 wt% graphene oxide (GO) nanosheets. The flexible LIB exhibits an upper voltage of 4.9 V, capacity of 0.13 mAh cm-2 and an energy density of 4.8 mWh cm-3. The battery is encapsulated using a simple lamination method that is economical and scalable. The laminated battery shows robust mechanical flexibility over 6000 bending cycles and excellent electrochemical performance in both flat and bent configurations. We will also present the fabrication and testing of a spiral stretchable Li-ion battery based on polymer nanocomposite electrolyte. Finite element analysis of both flexible and stretchable LIBs provides critical insights into the evolution of mechanical stresses during lamination, bending, and stretching.
2:00 PM - *ES05.06.02
Thermal Behaviour Investigations of Li(NiMnCo)O2 Cathode Materials
Petronela Gotcu-Freis 1 Show Abstract
1 , Karlsruhe Institute of Technology, Karlsruhe Germany
The susceptibility of lithium-ion batteries (LIB) containing lithium cobalt oxide (LiCoO2, or LCO) cathodes to thermal runaway was previously reported in the framework of safety studies for energy storage systems . The partial substitution of Co by other transition metals was much exploited. One of the main benefits of cells containing electrodes with new chemistries, such as lithium nickel manganese cobalt oxide (Li(NiMnCo)O2, or NMC, isostructural with the layered LCO), is the enhanced thermal stability in the fully charged state. To improve battery safety, thermal management systems (TMS) were introduced to control the operation of high energy and high power batteries. Therefore, knowledge of bulk electrode thermal properties such as thermal conductivity, thermal diffusivity and specific heat capacity are required to optimize TMS design models and for increasing the predictability of multiscale simulations .
The thermodynamic properties of NMC materials for LIB with layered structure were measured by calorimetry up to 973 K. Heat increment and specific heat capacity of samples with Ni:Mn:Co ratio of 1:1:1 and 4:4:2 were determined by transposed drop calorimetry and differential scanning calorimetry. Additionally, drop solution calorimetric measurements were performed on NMC samples with different Co, Ni and Mn contents. These studies on active materials were extended to cathode level for samples with controlled variable Ni content. The cathodes under investigation were tape-casted composite thick films, containing NMC active material mixed with additives (binder and carbon black), deposited on aluminium current collector foils. Galvanostatic cycling, cyclic voltammetry and entropymetry techniques were applied on half cells containing NMC materials. Comparative studies were carried out on samples containing the traditional LCO, prepared using the same methods as described previously .
It has been shown a correlation between thermophysical data, thermal properties and stoichiometry of the active materials. This study explains at cell component level the thermal runaway behavior of LIB. Our temperature dependent data are critical for significantly improving simulation studies of the thermal behaviour of LIB, including thermal runaway, since current approaches assume bulk properties to be independent of temperature due to lack of measured data.
 A. Manthiram, T. Muraliganth, in: C. Daniel, J. O. Besenhard (Eds.), Handbook of Battery Materials, Wiley-VCH Verlag GmbH & Co, Weinheim, Germany, 2011, pp. 343–375.
 D. Miranda, C. M. Costa, S. Lanceros-Mendez, J. Electroanal. Chem. 739 (2015) 97–110.
 P. Gotcu, W. Pfleging, P. Smyrek, H. J. Seifert, Phys. Chem. Chem. Phys. 19 (2017) 11920–11930.
2:30 PM - ES05.06.03
Degradation Analysis of Hybrid Silicon-Tin Anode for Lithium-Ion Batteries
Romeo Malik 1 , Melanie Loveridge 1 , Qianye Huang 1 , Krishna Manjunatha 2 , Shashi Paul 2 , Paul Shearing 3 , Rohit Bhagat 1 Show Abstract
1 Warwick Manufacturing Group, University of Warwick, Coventry, West Midlands, United Kingdom, 2 Emerging Technologies Research Centre, De Montfort University, Leicester, East Midlands, United Kingdom, 3 Department of Chemical Engineering, University College London, London, London, United Kingdom
This study investigates modes of degradation in hybrid silicon-tin anodes for Li-ion batteries, with emphasis on the electrode architecture. In recent years, considerable studies have shown that crystalline Si is a promising negative electrode candidate, with a specific capacity of 3579 mAh/g which is ca. 10 times the specific capacity of graphite. However, Si still has major performance issues associated with it, predominantly the volume expansion (up to 280%) which can result in cracking and pulverisation of active particles. Addition of tin to the silicon-based anode enhances performance by way of the decreased resistance from metallic tin improving cycling stability and charge capacity. The electrode macro and micro-cracking in the silicon based electrodes results in disintegration of the electrode architecture and leads to formation of “dead spots” (or loss of active materials). Incorporation of tin into the system is thought to help in reducing these electrically separated dead spots due to its conductive properties. The performance synergy between silicon and tin outperforms the individual contribution of each material alone.
It is imperative to comprehensively understand the fundamental degradation mechanisms inside anode microstructures and at their interfaces. X-ray computed tomography (CT), FIB-SEM tomography in conjunction with impedance spectroscopy and associated physical characterization, will be employed to capture and quantify key aspects of the evolution of internal morphology and resistance build up. This includes characterisation of SEI growth, porosity changes and conductive network breakdown during charge-discharge operation. The study will also include in-situ and operando tomography and diffraction experiments for clearer insights into key degradation processes, such as delamination, initiation and propagation of particle cracking as well as time-resolved identification of phase transformations. Tomography has been proven to be an effective tool to explore the hierarchical structure of battery electrodes and for diagnosing battery failure mechanisms at multiple- length scales. This approach will enable us to observe and quantify failures in Li-ion batteries at the electrode level, and thus facilitate construction of better electrode architectures.
This study aims to characterise electrode structures to be able to develop and correlate microstructural architecture with performance. It is anticipated that this study will influence major improvements in the design of Li-ion battery materials and their processing which in turn positively impact cell performance.
3:15 PM - *ES05.06.04
Structural Changes for Li3MF6 (M = V, Cr - Fe) Materials and Their Electrochemical Properties in Lithium-Ion Batteries
Michael Plews 1 , Martin Sarmiento 1 , Jenine Krakra 1 , Wanderlino Neto 1 , Yusuf Aslam 1 , Maseera Samreen 1 , Tanghong Yi 1 , Jordi Cabana 1 Show Abstract
1 , University of Illinois at Chicago, Chicago, Illinois, United States
Lithium Ion (Li-ion) batteries are often viewed as the missing link between producing and using low-carbon emission energy. In order to advance this technology, novel materials must be identified, synthesized and evaluated to challenge the current limits set by commercially produced cathode materials such as LiCoO2 and LiMn2O4. The quest for new materials has led to the exploration of unusual chemical spaces, such as ternary fluorides. By introducing highy ionic transition metal-fluorine bonds in the structure, the operating potential vs Li/Li+ can be raised, increasing energy density.
This work presents investigation into electrochemical properties of Li3MF6 (M = V, Fe). Previously, these materials have been seen to undergo intercalation at low potentials when ballmilled with carbon to enhance electronic conduction and reduced diffusion lengths through nanoparticle formation. Through x-ray diffraction and absorption spectroscopy, we reveal that these materials actually undergo a structural change during the milling process, meaning that the observed electrochemical activity has not been attributed to the correct crystal-chemical features. Therefore, we revisit this system by accurately defining the energetics of different polymorphs and their respective ability to undergo intercalation reactions relevant to battery electrodes. We extended the study to other transition metals, such as Cr and Mn, to assess whether the structural richness observed can be applied to other materials with interesting electrochemical properties.
3:45 PM - ES05.06.05
Effects of Binder-Silicon Interaction on Dispersion, Adhesion and Electrochemical Performance and Durability of Silicon Composite Electrodes for the Next Generation Lithium-Ion Batteries
Jiazhi Hu 1 , Yang-Tse Cheng 1 Show Abstract
1 Chemical and Materials Engineering, University of Kentucky, Lexington, Kentucky, United States
Silicon has been intensively studied as one of the most promising negative electrode materials for the next generation lithium ion batteries (LIBs). Although the choice of binder is crucial in determining the electrochemical performance and durability of silicon-based electrodes, the underlying mechanisms (e.g., mechanical vs. chemical) are unclear. In the present work, the influence of binder-silicon interaction on dispersion properties, adhesion strength, and the electrochemical performance and durability of silicon nanoparticle/carbon black/polymer binder electrodes have been investigated using a range of characterization methods, such as rheometer, optical microscope, scanning electron microscopy, Fourier transform infrared spectroscopy, and x-ray photoelectron spectroscopy, as well as measurement techniques such as peel adhesion test, nanoindentation, and electrochemical test. Two types of polymeric binders, polyvinylidene fluoride (PVDF) and sodium alginate, were chosen for this study. The results show that both PVDF and sodium alginate can absorb onto silicon nano-particles, forming a three-dimensional, gel-like structure. Because of a large number of carboxyl groups and hydrogen bonding, the slurry containing sodium alginate produces a much stiffer gel structure with higher elastic modulus and more uniform particle distribution than the slurries containing PVDF. Adhesion measurements demonstrated that the interfacial strength between sodium alginate and silicon is significantly higher than that between PVDF and silicon which results in both stronger cohesion within electrode and adhesion between electrode and current collector. With homogeneous particle distribution, better cohesion, and stronger adhesion, superior cell performance was ensured for silicon nanoparticle/carbon black/sodium alginate electrodes. With a deeper insight into the interaction between polymeric binder and silicon nanoparticles, this works provides a helpful guide to the design and optimization of LIB electrodes.
4:00 PM - ES05.06.06
Reducing the Fading Rate of Silicon Based Anodes for Li-Ion Batteries with Graphene and Ultra-Small Silicon Nanoparticles
Eugenio Grecoit 1 , Giorgio Nava 1 , Reza Fathi 1 , Francesco Fumagalli 1 , Eugenio Del Rio 1 , Simone Monaco 1 , Francesco Bonaccorso 1 , Vittorio Pellegrini 1 , Fabio Di Fonzo 1 Show Abstract
1 , IIT, Milano Italy
The combination of silicon nanostructures and carbon coatings, given the superior charge storage capacity (above 3000 mAh/g), represents one of the most attractive alternatives to the state of the art graphite (365 mAh/g) for next generation lithium ion batteries anodes. Silicon volume swelling upon lithiation (up to 300%) is efficiently tackled by the introduction of an optimized system of voids, whereas the carbonaceous covering ensures a stable solid electrolyte interface (SEI), thus increasing the cycling life of the anode material. The described architectures usually suffer however from low yield (45 mg/h) synthesis routes, not compatible with industrial requirements .
We propose Li-ion battery anodes composed by few-layer graphene (FLG) flakes and ultra-small (below 10 nm) silicon nanoparticles (SiNPs). The FLG flakes are produced by liquid phase exfoliation of pristine graphite while the SiNPs are synthesized by means of a plasma-assisted aerosol synthesis technique. The hybrid electrodes are realized by drop casting on a copper current collector a slurry paste 1:1:1 in mass ratio of FLG, SiNPs and a poly acrylic acid (PAA) binder followed by annealing in Ar/H2 atmosphere. The as-produced anode displays a specific capacity of 1520 mA h gsi-1, stable over 300 cycles with a Coulombic efficiency exceeding 99% at the 20th cycle in half-cell configuration. Comparison with amorphous carbon and graphene oxide conductive additives highlights the optimal synergy between the FLG flakes and ultra-small SiNPs, allowing reaching the best capacity retention upon cycling with an order of magnitude lower fading rate, as low as 0.04%. The obtained results coupled with the scalability of the FLG and SiNPs production methods offer a viable approach for the development of next generation Li-ion anodes based on nanomaterials arranged in hybrid configuration.
 C. K. Chan et al., ACS Nano 4, 1443-50 (2010)
Thursday PM, November 30, 2017
Hynes, Level 3, Room 309
4:15 PM - ES05.07.02
Conducting Polymer Coated Microfiber Electrode for High Energy Density Flexible Supercapacitor Application
Sangram Pradhan 1 , Bo Xiao 1 , Aswini Pradhan 1 , Messaoud Bahoura 1 Show Abstract
1 , Norfolk State University, Norfolk, Virginia, United States
Polypyrrole coated microfiber electrode with composite electrolyte based asymmetric all-solid-state supercapacitors having outstanding properties such as being flexible, ultrathin, and lightweight. This supercapacitor operates at higher voltage without any electrical breakdown. The fabricated supercapacitor based on microfiber electrode and composite electrolyte gave a very good specific supercapacitance as well as energy density. This device exhibits a high areal Csp of 5 F/g and superior cycling stability. The novel asymmetric APSCs also exhibit high energy density of 0.48 mW h/g, high power density of 35.2 mW/g, and superior cycling performance (<5% capacitance loss after 5 000 cycles at a high scan rate of 50 mV/s). This supercapacitor holds great potential for future flexible electronic devices.
4:30 PM - ES05.07.03
High Energy Density, All Screen-Printable Solid-State Microsupercapacitors Integrated by Graphene/CNTs Electrodes
Jui Kung Chih 1 , Ching Yuan Su 1 Show Abstract
1 , National Central University, Taoyuan Taiwan
Micro supercapacitors(MSCs) is an emerging energy storage devices, where the extremely high charge/discharge rate and high energy and power density, as well as high flexibility, make it a promising candidate toward wearable and on-chip electronics. However, most of the reported works integrate MSCs by micro-fabricating technology, which involves complicated and vacuum process, various chemical west, and high cost, hindering it for cost-effective and scalable production. Here we present an all-screen-printable method for fabricating all-solid(PVA: H3PO4) and flexible MSCs by rational designed composite electrodes of electrochemical exfoliated (EC-)graphene and long single-walled carbon nanotubes(CNTs). The systematic investigations are carried out on various electrode patterns, thickness, and the ratio of graphene/CNTs. A specific areal capacitance of 11.8 mF/cm2 and specific stack capacitance of 118 F/cm3 (at 5 mV/s)was achieved, which was superior to most of reported MSCs. Moreover, it exhibits a high cycling stability of 98% retention after 1000 cycles. It shows 90.2% capacitance sustention when the bending angle up to 180o, indicating excellent mechanical flexibility and operation stability. The extracted energy and power density of 16.4 mWh/cm3 and 294.8 W/cm3, which was, to our best knowledge, the highest performance for ultra-thin(<5 um) MSCs. This work provides a scalable and cost-effective method to produce solid-state MSCs with high energy density.
Summer Ferreira, Sandia National Laboratories
Judy Jeevarajan, Underwriters Laboratories Inc.
Hiroyuki Kubo, National Institute of Technology and Evaluation
Brittany Westlake, Electric Power Research Institute
ES05.08: Commercial Battery Risk Mitigation
Friday AM, December 01, 2017
Hynes, Level 3, Room 309
8:00 AM - *ES05.08.01
Propagation Behavior on Large-Scale Battery Energy Storage System (BESS)—Studies at Indoor Evaluating Facilities Characterized by the Thermal and Wind Velocity Control
Hideki Satake 1 , Satomi Naoi 1 , Ayami Takebe 1 , Hiroyuki Kubo 1 , Koichi Yamamoto 1 , Hiroki Ishigaki 1 Show Abstract
1 Global Center for Evaluation Technology (GCET), National Institute of Technology and Evaluation, Osaka Japan
In order to accelerate the acquisition of safety-related information on the large-scale BESS, NITE has launched the world’s first indoor-type evaluating facilities enabling us to evaluate the safety of the large-scale BESS with the temperature and wind velocity controlled. This paper will present the results of propagation test on the large-scale BESS executed under the indoor test environments that the temperature and wind velocity are securely controlled.
This experiment was executed at NLAB Large Chamber 1) (LC) of NITE, Osaka, Japan. As a test sample, it was decided to take the Lithium-ion battery module composed of 12 laminate-type cells there. The indoor temperature at the chamber was controlled to be 25±5°C while the wind velocity of inlets therein to be 1.5m/s. For the propagation, the test was conducted by burning the fuel oil to confirm the influence how incurred black smoke may affect the visibility.
3. Results and Discussion
Based on the experimental result of indoor temperature’s time change observed at LC, it was found that the temperature successfully reached to be within the ranges of 25±5°C throughout 24 hours. As checking the controllability of wind velocity inside LC, the velocity also reached to be about 1.5m/s above wind inlets while reaching around 0.1m/s at the center area of the chamber whose brick floor has no inlets. It was understood that the simultaneous and high-speed operation both of air-intake and air-exhaust set right above the inlets could successfully make great effects enabling us to acquire the detailed propagation behavior for long duration. It was also found that the changing conditions of tested samples were visually observed throughout all the durations when the propagation continued without black smokes’ interference. Furthermore, based on our understanding of acquired results from several tests completed therein, the temperature change measured in burning modules was observed to indicate the excellent reproducibility. This, in fact, reflects one of NLAB’s significant advantages that enable us to execute tests, regardless of outside temperature and climate. It is then fair to say that advantage of this NLAB may eventually boost the reliability of test results and can play the very critical role in providing more effective feedback of these data to the R&D researchers.
We have presented here that NLAB can bring us great advantages for evaluating the safety requirements of the large-scale BESS, based on the results obtained from the propagation test conducted at the world’s first indoor test facilities under thermal- and wind velocity-control. This novel test facility is expected to contribute not only for assuring the safety of BESS utilizers, also for effectively promoting the large-scale BESS at the world-wide scale, growing the battery-related markets and revitalizing the whole industry.
8:30 AM - ES05.08.02
Online Estimation of Lithium-Ion Battery Capacity Using Deep Convolutional Neural Networks
Sheng Shen 1 , Xiangyi Chen 2 , Chao Hu 1 2 , Mingyi Hong 3 Show Abstract
1 Department of Mechanical Engineering, Iowa State University, Ames, Iowa, United States, 2 Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa, United States, 3 Department of Industrial and Manufacturing Systems Engineering, Iowa State University, Ames, Iowa, United States
Over the past two decades, safety and reliability of lithium-ion (Li-ion) rechargeable batteries have been receiving a considerable amount of attention from both industry and academia. To guarantee safe and reliable operation of a Li-ion battery pack and build failure resilience in the pack, battery management systems (BMSs) should possess the capability to monitor, in real time, the state of health (SOH) of the individual cells in the pack. This paper presents a deep learning method, named deep convolutional neural networks, for cell-level SOH assessment based on the capacity, voltage and current measurements during charge. The unique features of deep convolutional neural networks include the local connectivity and shared weights, which enable the model to estimate battery capacity effectively using the measurements during charge. To our knowledge, this is the first attempt to apply deep learning to online SOH assessment of Li-ion battery. 10-year daily and weekly cycling data from implantable Li-ion battery cells are used to verify the performance of the proposed method. Compared with traditional machine learning methods such as relevance vector machine, the proposed method is demonstrated to produce higher accuracy and robustness in capacity estimation.
8:45 AM - ES05.08.03
Investigation of the Origin of Heat Generation in Commercial Lithium-Ion 18650-Cells
Kenza Maher 1 , MD Ruhul Amin 1 , Ilias Belharouak 1 Show Abstract
1 , Qatar Environment and Energy Research Institute (QEERI) at Hamad Bin Khalifa University (HBKU), Doha Qatar
Safety of battery modules and packs is extremely important whether they are used in consumer electronics, electric vehicles, or grid applications. There is a need for a fundamental understanding of the governing principles of battery thermodynamics in order to enhance the thermal behavior of battery devices. Batteries heat up during charge and discharge processes. Although, the origins of heat generation in batteries are not clearly understood, it is well known that they are dependent on several factors including temperature, state of charge and charge rate. In this work, we studied the heat released from three types of commercial lithium ion cells in charging and discharging modes under C/20, C/10, C/5, C/2 rates at the temperatures of 20, 30 and 40°C. It was found that the heat flow response depend of the cell chemistry. It was also found that several heat flow exotherms and endotherms occurred depending upon the state of charges, and that the heat flow features have opposite signs between charge and discharge, and that there is a significant increase of heat at increasing C-rates during charge and discharge.
Impedance spectra of same cells were measured at different charge-discharge states at the temperatures of 20, 30 and 40°C. Resistance trends, extracted from the equivalent circuits that simulate the EIS plots and represent the evolution of the electrochemical processes that take place in the cell, show that heat in a commercial lithium ion cells during charge and discharge is mainly due to resistive processes rather than to parasitic reactions when the cells are not subjected to extensive aging. A correlation between heat generation and structural transformations occurring during charge and discharge will be established in the light of the obtained thermodynamic results.
9:00 AM - *ES05.08.04
Experimental Approach to Multi-Cell Battery Resiliency across Multiple Lives
Lucia Gauchia 1 2 Show Abstract
1 Electrical and Computer Engineering Department, Michigan Tech University, Houghton, Ohio, United States, 2 Mechanical Engineering, Engineering Mechanics Department, Michigan Tech University, Houghton, Michigan, United States
Battery technologies find a wide variety of applications, from portable to transportation and grid services. In these applications, especially those that present a varying and complex context to battery operation, it is increasingly pressing to improve the understanding of failure and aging conditions, and to incorporate it to the energy management system. This is particularly necessary when considering battery re-purposing in second life. We will discuss experimental approaches for multi-cell and multi-life batteries, to provide empirical models and asses cell-to-system resiliency.
ES05.09: Commercial Cells Analysis
Friday AM, December 01, 2017
Hynes, Level 3, Room 309
10:00 AM - *ES05.09.01
Addressing Battery Safety Information Gaps Identified by the Fire Department of New York (FDNY) and the New York City Department of Buildings (DOB)
Britt Reichborn-Kjennerud 1 Show Abstract
1 Project Specialist, Con Edison, New York, New York, United States
Con Edison and NYSERDA undertook a battery safety lab testing and computer modeling program with the goal of addressing battery safety information gaps identified by the Fire Department of New York (FDNY) and the New York City Department of Buildings (DOB). Eight chemistries were tested including six lithium ion variants, a lead acid battery, and vanadium redox electrolyte. The scope of work, completed by DNV – GL in 2016, included small scale ignitions to measure gases, solids and liquids emitted during battery burns, heat release rates, and suppression agent testing. The small scale test results were extrapolated to the system scale using computer modeling. Medium scale behavior as well as the computer model fidelity were investigated through module burns and suppression tests. The testing results and findings, as well as notable first responder recommendations will be discussed.
10:30 AM - ES05.09.02
Materials Behavior at the Onset of Thermal Runaway Induced by Mechanical Abuses
Gabriel Veith 1 , Hsin Wang 1 , John Turner 1 Show Abstract
1 , Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States
Thermal runaway induced by mechanical abuse has become an important topic following the introduction of electric vehicles. Even with special vehicle designs and use of armor-like enclosures to protect the hundreds of batteries on board, the potential for mechanical damages to batteries during an accident still exist. We report our systematic studies on mechanical damages to Li-ion cells using experimental and computer simulation tools. Single cells and cell stacks were deformed by indentation or pinch. The depths of indentation were controlled with progressive steps. The deformation of the cell components were studied by x-ray computed tomography (XCT) non-destructively. The cells were also sectioned for optical scanning electron microscopy and opened up for post-mortem examination. Materials mechanical responses to deformation were found different in full-sized battery filled with electrolyte compared with single components or dry multiple-layer stacks. The on-set of internal short-circuit was captured and analyzed. The experimental results were used in computer simulations to validate the electrochemical and layer-resolved mechanical models.
10:45 AM - ES05.09.03
Higher Energy, Resilient LiCoPO4 Based Li-Ion Batteries
Jan Allen 1 , Samuel Delp 1 , Jeff Wolfenstine 1 , T. Jow 1 Show Abstract
1 , U.S. Army Research Laboratory, Adelphi, Maryland, United States
There is an ever-growing need for higher energy, resilient Li-ion batteries. LiCoPO4 is a promising cathode material to help fulfill this need owing to its relatively high discharge capacity of up to 167 mAh g-1 at a discharge potential of ~4.8V and the inherent abuse tolerance of phosphate based cathodes. However, LiCoPO4 based Li-ion cells show a severe loss of discharge capacity upon multiple charge – discharge cycles owing to structure deterioration and electrolyte decomposition. Partial substitution of Co by Fe significantly improves the cycle life and increases Li+ ion and electrical transport. Subsequent Cr and Si substitution for Co in LiCo1-xFexPO4 and electrolyte optimization further reduces capacity fade, substantially improves discharge capacity and reduces reactivity of the high voltage cathode with the electrolyte. Currently, we have achieved an energy storage capacity of > 700 Wh kg-1 of cathode material (87% of LiCoPO4 theoretical) which can be compared to a maximum theoretical 576 Wh kg-1 for commercialized LiFePO4. The capacity fade of Li / LiCo1-xMxPO4 half cells over 500 cycles is less than 6%. This paper will discuss modification of the cathode, the electrolyte – cathode interface and the electrolyte. The potential use of solid state and / or non-flammable liquid electrolytes to enhance performance and safety will be discussed.
11:00 AM - ES05.09.04
Propagating Thermal Runaway Failure in Lithium-Ion Batteries
Joshua Lamb 1 , Leigh Anna Steele 1 , Loraine Torres-Castro 1 , June Stanley 1 Show Abstract
1 , Sandia National Laboratories, Albuquerque, New Mexico, United States
Abusive battery testing has most typically dealt with the behavior of single cell failure. However, large and complex battery systems require the consideration of how a single cell failure may lead to a more serious failure that consumes a large portion of a pack or module. Initial failure that leads to the thermal runaway of other cells within the system creates a much more serious condition than the failure of a single cell. This work examines the behavior of small modules of cylindrical and stacked pouch cells after thermal runaway is induced in a single cell. The limits of cell-to-cell failure propagation are explored by initiating failure on cells with reduced states of charge, packs with air gaps between cells, and packs with physical separation between cells. This data shows both how thermal failure propagation may be mitigated as well as demonstrating the behavior of a propagating cell failure under these conditions. Some data shows how a propagating failure of even a small pack may stretch over several minutes as the latent heat available causes the cells impacted to slowly reach critical points where thermal runaway occurs. Work also shows how electrical connections may impact the failure. Measurements of unintended current flow in parallel configurations are made during the failure of a cell. This demonstrates another mechanism for a propagating thermal runaway.
Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia LLC, a wholly owned subsidiary of Honeywell International Inc. for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.
11:15 AM - ES05.09.05
Thermal Cross-Talk in Lithium-Ion Battery Safety
Aashutosh Mistry 1 , Partha Mukherjee 1 Show Abstract
1 Mechanical Engineering, Purdue University, West Lafayette, Indiana, United States
With Lithium-ion batteries being actively pursued for electric vehicle applications, their thermal safety becomes an important consideration along with their weight and size. These cells generate heat while in operation, given the electrochemical resistance of cell components. This heat generation scales positively with operating current. Even in the absence of external thermal abuse, this self-generated heat can increase the cell temperature beyond acceptable temperature limits, and can eventually lead to thermal runaway scenario.
Given the choice of electrode and electrolyte materials, heat generation rates are a strong function of electrode microstructure, and thus can be tuned by appropriate microstructure selection. The present talk investigates the effect of anode and cathode microstructure specifications on cell performance and thermal response. Individual contributions from each electrodes are quantified and microstructure based strategies to tune heat generation are suggested. A window of anode-to-cathode loading is identified that ensures stable cell operation and does not lead to either plating or thermal runaway.