Gleb Yushin, Georgia Institute of Technology
Bruce Dunn, University of California, Los Angeles
Arumugam Manthiram, University of Texas at Austin
Linda Nazar, University of Waterloo
SABIC Americas, Inc
Toyota Research Institute of North America
EE5.1: Advanced Intercalation Materials
Tuesday PM, March 29, 2016
PCC North, 100 Level, Room 124 B
2:30 PM - *EE5.1.01
Optimization Strategy of Li-Ion Cells and Beyond
Peter Lamp 1,Odysseas Paschos 1,Filippo Maglia 1
1 BMW AG Munich Germany,Show Abstract
Recent history has shown that electromobility is capable to offer a dynamic driving experience without local emissions, raising the expectations from politics, OEMs, and customers. Today the electrification of the drive train ranging from hybrid vehicles to plug-in hybrids and finally to pure electric vehicle is the commonly accepted next step in this direction. BMW is strongly committed to this path. In particular this is expressed by the launch of its sub-brand BMW i dedicated to electric vehicles.
Nonetheless the challenges for mass market penetration are far from being solved. The share of electric vehicles in the world's automotive market is increasing at a slower rate than expected and cost-to-range ratio can be easily identified as the main factor. An electromobility model based on a daily use in urban environment might not be sufficient to achieve large customer acceptance. Driving ranges of at least 300 miles might then be required to guarantee the success of future electric vehicles.
Although an increase in volumetric and gravimetric energy densities is still possible by improvements of cell, modules, and battery packs design as well as through optimized sub-components, the development of novel anodes, cathodes, and electrolytes seems at this point mandatory. The necessity to develop new materials that allow for the simultaneous achievement of higher energy density, maintaining at the same time similar, or improved, rate capability, lifetime, cost, and safety represents a tremendous challenge. Considerable improvements must be obtained in this respect before a possible industrialization of the new generations of batteries for automotive application can be envisaged.
For this purpose BMW has initiated a research effort dedicated to the fundamental investigation of future lithium technologies, with particular attention dedicated to lifetime and safety. The research activities cover all the different levels, including materials, interfaces, cell, and pack, where battery degradation processes can originate. Additionally, novel cell concepts are investigated and will be discussed.
3:00 PM - *EE5.1.02
Progress in High Capacity Core-Shell and Concentration Gradient Cathode Materials for Lithium-Ion Batteries
Yang-Kook Sun 1
1 Department of Energy Engineering Hanyang University Seoul Korea (the Republic of),Show Abstract
High energy density rechargeable batteries are needed to fulfill various demands such as self-monitoring analysis and reporting technology (SMART) devices, energy storage systems, and (hybrid) electric vehicles. As a result, high-energy electrode materials enabling a long cycle life and reliable safety need to be developed. To ensure these requirements, new material chemistries can be derived from combinations of at least two compounds in a secondary particle with varying chemical composition and primary particle morphologies having a core-shell and concentration gradient structure and spherical cathode active materials, specifically a nanoparticle core and shell, nanoparticle core and nanorod shell, and nanorod core and shell. To this end, several layer core-shell cathode materials were developed to ensure high capacity, reliability, and safety.
3:45 PM - *EE5.1.03
Pushing the Frontiers of Intercalation for Lithium Batteries
M. Stanley Whittingham 1,And Necces 1
1 SUNY-Binghamton Binghamton United States,Show Abstract
Essentially all commercially available Li-Ion batteries today have capacities of under 200 mAh/g theoretical and in single cells do not significantly exceed 200 Wh/kg. It should be possible by “closing the gap” between the theoretical and practical capacities of the layered oxides, LiMO2, to approach 250 mAh/g. An alternative approach, which will be the main topic of this presentation is to achieve a redox approaching 2 electrons per transition metal center using Li as the mobile specie, rather than Mg. Our model compound is VOPO4 which can form Li2VOPO4 in a reversible manner . It is achieving capacities approaching 300 mAh/g. This material is very stable to thermal runaway unlike most other cathode materials and is readily synthesized either by solid state techniques or by solvothermal methods. Our latest results on this compound will be discussed. Using such materials or fully reacting LiMO2 in a carbon-free anode system should allow the attainment of 350 Wh/kg and 1 kWh/liter at the cell level. This work is supported by DOE BES EFRC NECCES under award # DE-SC0012583.
 Chem. Rev. 114, 11414, 2014
4:15 PM - *EE5.1.04
Storage Mechanisms of Li and Na Batteries: Thermodynamic and Kinetic Aspects
Joachim Maier 1
1 Max-Planck-Inst Stuttgart Germany,Show Abstract
The various storage mechanisms for Li and Na batteries are considered and analyzed in terms of charge carrier chemistry.1 The analysis enables one to identify key adjusting screws for optimizing electrochemical performance.
In particular, the contribution addresses the following questions: What is the effect of doping on electrochemical performance? How can size effects be exploited for varying thermodynamic parameters (cell potential), rate performance or even storage mechanisms? How can phase distribution (morphology) be optimized with respect to performance? How to make conversion reactions reversible? How to exploit interfacial storage?
1. J. Maier, Angew. Chem. Int. Ed., 2013, 52(19), 4998.
4:45 PM - EE5.1.05
Overcharging the Layered NMC and NCA Oxides; Impact on Electrochemistry and Crystal Structure
Lamuel David 1,Debasish Mohanty 1,Jianlin Li 1,David Wood 1,Claus Daniel 1
1 Oak Ridge National Lab Oak Ridge United States,Show Abstract
Today’s energy storage devices in electric vehicles require advanced high-power, high-energy-density lithium-ion batteries (LIBs). LIB energy density is directly proportional to specific capacity and average operating voltage. The layered Ni-Mn-Co (NMC) and Ni-Co-Al (NCA) oxides have shown remarkable cycle life and structural stability when cycled at a nominal upper-cutoff voltage (UCV) of 4.2 V. However, they have lower energy density than other layered oxide systems (for example, Li-Mn-rich oxides). The energy density of NMC and NCA cathodes can be dramatically increased by cycling them to high UCV; however, the capacity fade that might occur due to structural rearrangements at high UCV remains a challenging issue. This paper presents our detailed investigation of electrochemistry and crystal structures of baseline NMC and NCA cathodes and of cathodes cycled at high UCV (4.2–4.8 V). The electrochemistry revealed that the optimum UCV for these oxides was 4.55 V; a stable capacity of ~180 mAh/g was observed when they were cycled at a rate of 2C. Capacity retention was greater than 75% and 80% when they were cycled for 70 cycles at 1C and C/3, respectively. Diffraction, microscopy, and magnetization tools were employed to investigate the crystal structures of the cycled cathodes and to obtain insights into the structure-electrochemistry correlation when they were operated at high UCV.
5:00 PM - *EE5.1.06
Olivine with Zero Anti-Site Defect and Three Dimensional Lithium Diffusion Paths
Kisuk Kang 1,Kyu-Young Park 1
1 Seoul National Univ Seoul Korea (the Republic of),Show Abstract
Lithium iron phosphate (LFP) has attracted tremendous attention as a next-generation electrode material in lithium rechargeable batteries for large scale energy storage systems due to the use of low-cost iron and chemical/electrochemical stability. While the lithium diffusion in LFP, the essential property in battery operation, is relatively fast due to the one-dimensional tunnel present in the olivine crystal, the tunnel is inherently susceptible to immobile anti-site defects which, if any, block the lithium diffusion and lead to the inferior performance. Herein, we demonstrate that the kinetic issue arising from the defects in LFP can be completely eliminated in a new olivine LFP, which we successfully synthesized for the first time. The doping in the olivine structure reduces the concentration of defects in the tunnel by 7 orders of magnitude. Moreover, it opens up a new lithium diffusion path along the  direction making the olivine LFP as a three-dimensional lithium diffuser. We also find that the intrinsic energy barrier for phase transition gets notably lower in the lithium excess olivine LFP. The fundamentally different nature of the new olivine than normal LFP additionally induces faster charging capability, lowering thermal solid-solution temperature and less memory effect.
5:30 PM - *EE5.1.07
Tire-Derived Carbon Composite Electrodes for Energy Storage Applications
Mariappan Paranthaman 1,M Boota 2,Yunchao Li 1,Kokouvi Akato 1,Amit Naskar 1,Yury Gogotsi 2
1 Oak Ridge National Lab Oak Ridge United States,2 Drexel University Philadelphia United StatesShow Abstract
The main goal of this research is to develop a method to modify the characteristics of the recovered carbon composites starting from recycled, low-cost, and abundant tires and demonstrate its feasibility as electrodes in batteries and supercapacitor applications. U.S. is generating almost 300 million scrap tires every year. Proper disposal and recycling of worn-out tires prevent the threats large piles of them pose to the environment and to public health and safety. Hence, recycling hazardous tires to produce value-added products is essential for the sustainability of our society. We have developed recently a method to recover carbon composites through sulfonation followed by pyrolysis of tires and demonstrated its use as anodes in both lithium- and sodium-ion batteries. In addition, we have also demonstrated that the recovered carbon composites can be activated and coated with polyaniline to form polymer carbon composite films that are suitable as electrodes for supercapacitor applications. We will report the current status of the tire-derived carbon composite powder scale up efforts and its use in energy storage applications.
EE5.2: Poster Session I: Next-Generation Battery Materials and Devices
Wednesday AM, March 30, 2016
Sheraton, Third Level, Phoenix Ballroom
9:00 PM - EE5.2.01
Printed Air Cathode for Flexible and High Energy Density Zinc-Air Battery
Soorathep Kheawhom 1
1 Chulalongkorn Univ Bangkok Thailand,Show Abstract
Flexible zinc-air batteries were fabricated using an inexpensive screen-printing technique. The anode and cathode current collectors were printed using commercial nanosilver conductive ink on a polyethylene terephthalate (PET) substrate and a polypropylene (PP) membrane, respectively. Air cathodes made of blended carbon black with inexpensive metal oxides including MnO2 and CeO2, were studied. The presence of MnO2 and CeO2 in the printed air cathodes could enhance the oxygen reduction reaction which is the most important cathodic reaction in zinc-air batteries. Consequently, the batteries using air cathodes with blended metal oxides showed a relatively higher energy density in comparison to the battery using air cathode without metal oxides. Finally, the batteries were tested for their flexibility by bending them so that their length decreased from 100% to 50%. The results showed that the bending did not affect characteristics on potential voltage and discharging time of the batteries fabricated.
9:00 PM - EE5.2.02
Printed Flexible Zinc-Air Battery Using an Alkaline Polymer Gel Electrolyte
Soorathep Kheawhom 1
1 Chulalongkorn Univ Bangkok Thailand,Show Abstract
Flexible zinc-air batteries were fabricated using an inexpensive screen-printing technique. The anode and cathode current collectors were printed using commercial nanosilver conductive ink on a polyethylene terephthalate (PET) substrate and a polypropylene (PP) membrane, respectively. An alkaline polymer gel electrolyte (PGE) film prepared by polymerization of acrylate, potassium hydroxide and water was used as a quasi-solid-state electrolyte without a separator. The PGE film has almost the same chemical and electrochemical stability as aqueous alkaline solution. The molar concentration of potassium hydroxide used was optimized in view of the characteristics on potential voltage, energy density, discharging time and flexibility of the batteries fabricated. The batteries fabricated using PGE had good performance characteristics and good flexibility in comparison to the battery using PP membrane separator with alkaline solution electrolyte. Moreover, using PGE film could extend shelf-life of zinc-air batteries.
9:00 PM - EE5.2.03
Lithium Iodide as a Promising Electrolyte Additive for Lithium-Sulfur Batteries: Mechanisms of Performance Enhancement
Feixiang Wu 1,Jung Tae Lee 1,Naoki Nitta 1,Hyea Kim 1,Oleg Borodin 2,Gleb Yushin 1
1 School of Materials Science and Engineering Georgia Institute of Technology Atlanta United States,2 Electrochemistry Branch Army Research Laboratory Adelphi United StatesShow Abstract
Achieving higher energy density, lower-cost, safer and more stable rechargeable batteries have been motivated by the rapidly rising market demand of advanced energy storage systems for use in transportation, electric grid and telecommunication. The use of Li-ion batteries is growing rapidly and playing an important role in our life due to their high specific energy and energy density. However, the current commercial cathode materials for Li ion cells are mainly Co-based and Ni-based intercalation-type cathode materials or lithium iron phosphate, which are relatively expensive and display theoretical capacities of ~300 mAhg-1. The low cost sulfur, working as cathode materials, is promising candidate with stimulant theoretical specific capacities of 1675 mAhg-1, which have been viewed by many authors as the next-generation lithium chemistry that offers improved safety and higher energy density [1-3]. Compared to S, The fully-lithiated Li2S can work with safer Li-free anodes, which makes it a more promising cathode material for rechargeable Li and Li-ion batteries [3-5].
Here, we report on the significant enhancement of electrochemical performance of Li2S/Li cells when lithium iodide (LiI) is used as a novel additive in organic electrolytes . LiI-containing cells show near-theoretical capacity utilization and excellent cycle stability. Our studies reveal that the LiI induces formation of Li ion permeable protective films on both the cathode and anode sides of the cell in-situ, which prevent the dissolution of polysulfides on cathode and reduction of polysulfides on anode, respectively, and keep the battery cost low and insure high coating uniformity. As a result, over 95.0% of the initial capacity is retained after 100 cycles, comparing to less than 77% for the cell without this additive. The addition of LiI into electrolyte also decreases the over-potential of 1st charge and voltage hysteresis. The cell rate performance was significantly enhanced with LiI additions. Since the reduction potential of the utilized electrolyte solvents is significantly smaller than the discharge potential for our cathodes, such finding is rather unexpected. Post-mortem analysis in combination with quantum chemistry studies provided insights on the mechanisms of the observed film formation and the resulting performance enhancements.
 P. G. Bruce, S. A. Freunberger, L. J. Hardwick, J. M. Tarascon, Nature materials 2012, 11, 19.
 X. Ji, K. T. Lee, L. F. Nazar, Nature materials 2009, 8, 500.
 F. Wu, H. Kim, A. Magasinski, J. T. Lee, H. T. Lin, G. Yushin, Advanced Energy Materials 2014, 4, 1400196.
 F. Wu, J. T. Lee, A. Magasinski, H. Kim, G. Yushin, Particle & Particle Systems Characterization 2014, 31, 639.
 F. Wu, A. Magasinski, G. Yushin, Journal of Materials Chemistry A 2014, 2, 6064.
 F. Wu, J. T. Lee, N. Nitta, H. Kim, O. Borodin, G. Yushin, Advanced materials 2015, 27, 101.
9:00 PM - EE5.2.04
Novel Formulations for Stable, High-Performance Li-Based Battery Electrodes Nanoarchitectures Based on Graphene Related Materials
Sanju Gupta 1,Jared Walden 1
1 Western Kentucky University Bowling Green United States,Show Abstract
Electrochemical energy storage and conversion systems represent some of the most efficient and environmentally benign technologies and the need for next generation stable, high-performance electrode materials and architectures is the driving force. The interaction between graphene-based and other nanomaterials allows emergent novel architectures and tunable physical properties such as specific surface area combined with catalytic properties, mechanical strength, and facile electron and ion transport via higher electron mobility and conductivity. This work presents the development and deployment of 1) graphene-encapsulated mesoporous silicon (G-Si) anodes for Li-ion battery (LIB) accommodating large volume changes and 2) carbon-sulfur nanocomposite coated with reduced graphene oxide cathodes to confine polysulfides, a potential successor of LIB, as practically viable high-performance Li-based batteries delivering their energy to load on demand. For former, controlled B-doped mesoporous Si nanospheres are synthesized by facile electroless etching followed by carbon coating for stable solid-electrolyte interphase (SEI) layer and wrapping with reduced graphene oxide (rGO) nanoplatelets. The latter cathodes are deposited following sulfur-coated graphene enhancing charge transfer kinetics and graphene matrix filled with elemental sulfur effectively confining sulfur and polysulfides methods. We have characterized the structure using complementary techniques revealing surface morphology and C-Si and C-S interfaces. We discuss our recent achievements in Li-ion and Li/S cells that have been facilitated by the application of graphene, together with the electrochemical reaction mechanisms and improved performance. The knowledge gained can tap into next-generation scalable high energy density LIB for space applications. We gratefully acknowledge the financial support by WKU Research Foundation.
9:00 PM - EE5.2.05
Nitrogen-Doped Graphene Nanosheets/Sulfur as Cathode Material for Room-Temperature Sodium-Sulfur Battery
Yong Hao 1,Xifei Li 2,Chunlei Wang 1,Richa Agrawal 1
1 Florida International University Miami United States,2 Tianjin Normal University Tianjin ChinaShow Abstract
Sodium, with high abundance, low cost, and suitable redox potential advantages, is a promising alternative as an anode material. Sulfur, as one of the most abundant elements on earth, is becoming one of the most attractive cathode materials for high energy and high power density batteries. In this work, Nitrogen-doped graphene nanosheets (NGNS) interlinked with sulfur has been used as an electrode material for room-temperature (RT) sodium-sulfur batteries. This nanocomposite was synthesized via an environmental-friendly chemical reaction-deposition strategy and followed by low temperature heat treatment. High and low sulfur content levels in the nanocomposites have been developed. Characterizations testing such as SEM, XPS and XRD have been applied on samples and electrochemical testing as cyclic voltammetry (CV), galvanostatic charge-discharge and cycling performance have been carried out. Based on the results, the first cycle discharge/charge capacities of the low loading sulfur-NGNS composite at 0.05C have been reached 212 mA h g-1 and 181 mA h g-1. The low loading sulfur-NGNS composite also presented notable cycling life with 300 cycles at 0.1C and the capacity remained at 55 mA h g-1, indicating good cycling retention. Detailed discussion on the characterization and electrochemical performance of the synthesized NGNS/S nanocomposite will be presented in the meeting.
9:00 PM - EE5.2.07
High Performance Sulfur Cathodes Based on Regenerative Polysulfide-Scavenger Layers
Fang Liu 1,Yunfeng Lu 1
1 Univ of California-Los Angeles Los Angeles United States,Show Abstract
Lithium sulfur batteries, notable for high energy density, environmental benignity and low cost, hold great potentials for next-generation energy storage systems. However, continuous formation and outward diffusion of lithium polysulfides result in low utilization of active materials, serious capacity decay during resting and cycling, and limit their further adaptations. Here, we designed and constructed regenerative polysulfide-scavenger layers (RSL) based on adsorption near the cathode, to address the migration of sulfur species. Li-S batteries, adapted from the proposed strategy achieved a high utilization of active materials, ultra-low self-discharge rate and excellent capacity retention at 1C. The improved performance is strongly associated with the interactions between RSL and lithium polysulfides and the fundamental mechanism behind the excellent performance was discussed. The concept serves as a structural basis to solve polysulfide migration, and a design framework to develop high performance Li-S batteries.
9:00 PM - EE5.2.08
O and N Ion Battery with Transition Metal as Anode
Satyesh Yadav 1,Blas Uberuaga 1
1 Los Alamos National Laboratory Los Alamos United States,Show Abstract
Several transition metals are known to dissolve high percentage of oxygen. We investigate the possibility of using transition metals as anode materials with N, O, or F as conducting ions. Two important factors that are required for metal to act as good candidate for metal-air batteries are: i) ease of N, O, or F intercalation and ii) small volumetric changes as the concentration of dissolved oxygen is varied. In this study using first-principles density functional theory (DFT) and hybrid-DFT, we study thermodynamic stability of N, O, or F interstials and corresponding volumetric change in range of metals.
We study transition metals from period 4, 5, and 6. We compare N, O, or F interstial formation energy with formation energy per N, O, or F of corresponding most stable oxide, nitride, and fluoride. As an outlier to rest of metals considered, we find that it is thermodynamically favorable to form O and N interstial compared to its most stable oxide and nitride in Ti, Zr, Hf, and V, respectively. This provides a thermodynamic driving force for O or N to diffuse into Ti, Zr, Hf, and V metals rather than forming oxide layer. There is a very small volumetric expansion due to O and N interstitial in Ti, Zr and Hf but large for V. These results suggest that Ti, Zr, and Hf can be suitable candidate for O or N ion battery.
9:00 PM - EE5.2.09
Two-Dimensional Gallium Sulfide Nanosheets Produced by Liquid-Phase Exfoliation of Commercial Layered Powders: High Capacity Anode for Advanced Li-Ion Battery
Chuanfang (John) Zhang 1,Sang Hoon Park 1,Oskar Ronan 1,Andrew Harvey 1,Sean O'Brien 1,Jonathan Coleman 1,Valeria Nicolosi 1
1 Trinity College Dublin Dublin Ireland,Show Abstract
The ever-increasing demand of advanced lithium-ion batteries (LiBs) require the electrode materials possessing exceptional electrochemical performances, cost-effective properties and the capability of scaling up.1 Liquid-phase exfoliation of commercial bulk powders which produces two-dimensional (2D) defect-free nanosheets, is not only an economic route but also having the potential of scalable production.2–5 As a family member of III-VI layered semiconductors, gallium sulfide (GaS) has many exciting properties, among which is the potential in LiBs. Here we exfoliated the commercial GaS powders to obtain the 2D GaS nanosheets,6 followed by hybridizing with single-wall carbon nanotubes (SWCNT) to form a free-standing composite paper electrode. As the LiBs anode, the flexible composite paper shows a high gravimetric capacity of 800 mAh g-1 at 100 mA g-1 and still retains 270 mAh g-1 at 1000 mA g-1. These values are much higher than the reported ones.7 The capacity of GaS component in the composite paper is over 1000 mAh g-1 at 100 mA g-1, which greatly exceeds the values of GaS electrode without SWCNT. This result clearly indicates the synergistic effect between the high-capacity GaS nanosheets and the conductive SWCNT. Furthermore, it was found that through using the electrolyte additive, the formation of solid-electrolyte interphase (SEI) could be suppressed, resulted in much improved cycling performance and rate capability in the flexible composite paper. Finally, effect of mass loading on the capacity of composite paper electrode, both gravimetrically and volumetrically, has been studied. These results imply that the great potential of GaS/CNT flexible paper electrode as the anode for advanced LiBs.
1 P. G. Bruce, B. Scrosati and J.-M. Tarascon, Angew. Chem. Int. Ed. Engl., 2008, 47, 2930–46.
2 K. R. Paton, E. Varrla, C. Backes, et al., Nat. Mater., 2014, 13, 624–30.
3 Y. Hernandez, V. Nicolosi, M. Lotya, et al., Nat. Nanotechnol., 2008, 3, 563–8.
4 J. N. Coleman, Acc. Chem. Res., 2013, 46, 14–22.
5 M. Lotya, Y. Hernandez, P. J. King, et al., J. Am. Chem. Soc., 2009, 131, 3611–20.
6 A. Harvey, C. Backes, Z. Gholamvand, et al., Chem. Mater., 2015, 27, 3483-3493.
7 X. Meng, K. He, D. Su, et al., Adv. Funct. Mater., 2014, 24, 5435–5442.
9:00 PM - EE5.2.10
Fabrication of One-Dimension Li7La3Zr2O12 Using Biomass Template
Xiaogang Han 1,Xiaofeng Yang 2
1 University of Maryland, College Park College Park United States,2 Department of Chemistry, School of Science North University of China Taiyuan ChinaShow Abstract
Garnet-type lithium ion conductor Li7La3Zr2O12 (LLZO) has received great attention toward development of all solid-state lithium ion batteries due to its high lithium ion conductivity and relative stability against lithium metal at room temperature. Currently, more efforts focus on studying the effect of crystal structure on lithium ion conductivity. However, the physical morphology of LLZO garnet also has important influence on its total ionic conductivity for practical application. In this paper, one dimensional LLZO was successfully synthesized using naturally bio-mass kapok fiber as template. It showed that the hollow structure of kapok and heating rate both played important roles on the fiber-like structure formation. The total ion-conductivity of the LLZO pellets reached up to 1.30×10-4 S cm-1. In addition, an LLZO ink was also obtained by dispersing the fibers in solvent, and exhibited Newtonian fluid property in a large range, which has potential application for flexible and wearable solid-state batteries.
9:00 PM - EE5.2.11
One-to-One Comparison of Silicon Nanolayer-Embedded Graphite Anodes with Commercial Benchmarking Materials as Feasible Candidates for High Energy Lithium-Ion Battery
Namhyeong Kim 1,Jaephil Cho 1
1 UNIST (Ulsan National Institute of Science and Technology) Ulsan Korea (the Republic of),Show Abstract
To date, in practical lithium ion batteries (LIBs), the commercial application of pure Si as anode material is tough challenge due to its intrinsic drawbacks including tremendous volume variation during the repeated lithium alloying/dealloying reaction. In this respect, the SiOx , whose the reversible capacity is about 1600mAh g-1 with 74% of initial coulombic efficiency, has been extensively researched as strong alternative because it shows the enhanced cycle stability and low volume change during electrochemical reaction compared with pure Si. Recently, to increase capacity of the anode electrode, the graphite composite with SiOx (3wt %) has been used in full cells. However, even though the SiOx can provide a high capacity as high as 1600mAh g-1, due to its low initial efficiency, the increment of the SiOx proportion is a crucial issue for the Li-finite full-cell system. In our previous report, through the industrial-relevant designed CVD which is possible to make a mass production, we successfully synthesized Si nanolayer-embedded graphite/carbon hybrids (SGC) exhibiting a high reversible capacity (523mAh g-1) with excellent coulombic efficiency (92%) at a 1st cycle and remarkable capacity retention (96%) after 100 cycles.
Herein, we have intensively focused on the one-to-one comparison between SGC and state-of-the-art benchmarking samples including the SiOx and Si/graphite composite which have been supplied as commercial anode in major battery companies. For a direct comparison, the specific capacity of all samples were fixed at 420mAh g-1 by graphite blending as the forthcoming LIB anode and all electrochemical tests were conducted at real industrial electrode condition such as high electrode density (> 1.6g cc-1), high areal capacity (> 3.0 mAh cm2) and limited SBR/CMC binder composition (< 4wt %) . The electrochemical evaluations, also, were reported in the full-cell as well as in the half-cell configurations. As a result, the performance of the SGC blending system achieved outstanding cycle retention (< 98%) in the half-cell after 50th cycles and also allowed the highest coulombic efficiency (
9:00 PM - EE5.2.12
Nanostructured Iron and Nickel Electrodes for Rechargeable Alkaline Batteries
Danni Lei 1,Dong-Chan Lee 1,Alexandre Magasinski 1,Enbo Zhao 1,Daniel Steingart 2,Gleb Yushin 1
1 Georgia Institute of Technology Atlanta United States,2 Princeton University Princeton United StatesShow Abstract
Flammability and high cost of lithium ion batteries limit their market adoption rate in price-sensitive applications. Therefore, rechargeable aqueous batteries have attracted renewed attention due to their environmental friendliness, the intrinsic flame resistance of aqueous electrolytes, most importantly, greatly reduced capital and operating cost.1-3 Recently, we successfully utilized a solution-based synthesis of strongly coupled nanoFe/multiwalled carbon nanotube (MWCNT) and nanoNiO/MWCNT nanocomposite materials for use as anodes and cathodes in rechargeable alkaline Ni-Fe batteries. The produced aqueous batteries demonstrate very high discharge capacities, which exceed that of commercial Ni-Fe cells by nearly an order of magnitude at comparable current densities. The use of highly conductive MWCNT network allows for high capacity utilization due to rapid and efficient electron transport to active metal nanoparticles in oxidized (such as Fe(OH)2 or Fe3O4) states. The flexible nature of MWCNTs accommodates significant volume changes taking place during phase transformation accompanying reduction-oxidation reactions in metal electrodes. The electrolyte molarity and composition have a significant impact on the capacity utilization and cycling stability. Based on our post-mortem analyses, we came to the following conclusions: (i) at high alkaline electrolyte concentration and thus high pH values the Fe dissolution and re-precipitation takes place, which reduces the rate performance and capacity utilization of the nanostructured Fe anodes; (ii) at lower pH values Fe dissolution could be mitigated, but hydrogen evolution (HE) takes place, which becomes particularly significant if high surface area nanostructured Fe anodes are used; (iii) the addition of LiOH to KOH electrolyte enhances the Fe dissolution, but reduces the anode polarization and capacity utilization; these findings correlate well with the formation of porous oxidized Fe in LiOH-comprising electrolytes.
 S. Liu, G. L. Pan, N. F. Yan, X. P. Gao, Energy Environ. Sci., 2010, 3, 1732.
 C. Xu, B. Li, H. Du, F. Kang, Angew. Chem. Int. Ed. 2012, 51, 933.
 Z. Liu, S. W. Tay, X. Li, Chem. Commun., 2011, 47, 12473.
This work was partially supported by the Advanced Research Projects Agency- Energy (grant DE-AR0000400).
9:00 PM - EE5.2.13
Rechargeable Ni-Na Aqueous Battery with Hierarchical Nanostructured Ni(OH)2 Electrodes
Seungyoung Park 1,Ziyauddin Khan 1,Youngsik Kim 1,Hyunhyub Ko 1
1 Ulsan National Institute of Science and Technology(UNIST) Ulsan Korea (the Republic of),Show Abstract
The development of rechargeable battery systems have recently accelerated the various energy storage applications from portable electronic devices to hybrid electrical vehicles. Nickel-metal hydride (Ni-MH) battery has a high capacity (2-3 times than that of an equivalent size NiCd battery) at an energy density similar to that of a lithium-ion battery. In addition, its aqueous electrolyte system is safer than the Li-ion battery, where the aprotic electrolyte system causes the flammable problem especially in the hybrid electric vehicles. However, its cell voltage is low (1.32 V) because of the aqueous electrolyte system. It is important to meet both the high cell voltage and high cell capacity in the aqueous electrolyte system for practical applications.
Herein, we propose a rechargeable Ni-Na aqueous battery system with Na electrode and wrinkled Ni-based nanostructures as anode and cathode materials, respectively. Na based rechargeable battery system has recently attracted great attentions as the next-generation battery system because of the similar mechanism with the Li-based rechargeable battery system and their abundant reserves. In addition, as the anode material, 3D-wrinkled Ni-based nanostructures are directly constructed on carbon microfibers offering the binder-free electrodes. The 3D Ni-based wrinkled nanostructure shows an enhanced performance with high surface area and high capacity (280mAh/g at rate of 1mA). Importantly, the Ni-Na battery offers the high average discharge voltage (3.1V) and shows a high capacity resulting in the high energy density (837Wh/kg).
9:00 PM - EE5.2.14
Metal Oxychloride/Metal Electrode Systems for Chloride-Ion Batteries
Xiangyu Zhao 1,Meng Yang 1,Xiaodong Shen 1
1 Nanjing Tech University Nanjing China,Show Abstract
Rechargeable batteries are receiving particular attention in diverse areas of portable electronic devices, electric vehicles (EV) and other energy storage systems. We previously reported the proof-of-principle of a new concept of rechargeable batteries based on chloride shuttle, i.e., chloride ion batteries. The concept has the advantage of a broad variety of potential electrochemical couples with high theoretical energy density up to values of 2500 Wh/L, which is higher than the theoretical energy density of the current lithium ion battery. Moreover, chloride ion batteries can be built from abundant material resources and have environmentally friendly features. These attributes could make the chloride ion battery a potential alternative in the field of rechargeable batteries.
A key challenge is to suppress the dissolution of cathode materials mainly composed of transition metal chlorides, which are Lewis acid and can react with a Lewis base containing chloride ion in the electrolyte, resulting in the formation of soluble complex ions. One approach is to use metal oxychlorides as cathode materials. For the FeOCl cathode (FeOCl/Li), a reversible discharge capacity of 184 mAh g-1 was measured, which is based on the phase transformation between FeOCl and FeO. Two stages of this phase transformation are observed for the FeOCl cathode. These results suggest that metal oxychlorides are promising cathode materials for chloride ion batteries.
An advantage of chloride ion batteries is the use abundant materials such as Mg, La, Ca and Na as anode materials. We found that Mg is promising as anode material based on our new results. For instance, the BiOCl cathode (BiOCl/Mg) showed a discharge capacity of 70 mAh g-1, i.e., 68% of theoretical capacity at the second cycle. The electrochemical performance of metal oxychloride/Mg systems was investigated including single electron or multi-electron cathode. Moreover, a new approach was tested using multi-electron vanadium oxychloride (VOCl) cathode and Mg/MgCl2 composite anode.
9:00 PM - EE5.2.15
A Computational Study of Lithium Interaction with Tetracyanoethylene (TCNE) and Tetracyaniquinodimethane (TCNQ) Molecules for Organic Batteries
Sergei Manzhos 1,Yingqian Chen 1
1 National Univ of Singapore Singapore Singapore,Show Abstract
Organic batteries are an extremely promising electrochemical storage technology as they promise high rate (high power) and sustainable batteries with environment-friendly inputs. Organic batteries are also promising for the development of post-lithoum batteries such as sodium ion batteries. While there is a growing body of experimental works studying various potential organic electrode materials, theoretical/computational studies are rare; they are however essential to guide rational as opposed to ad hoc design of better organic electrode materials.
Here, we present a study of the mechanism of interaction of Li with molecules which are promising for use in organic electrodes: tetracyanoethylene (TCNE) and tetracyaniquinodimethane (TCNQ). TCNE and TCNQ have previosuly been proposed as promising candidate materials for organic battery electrodes, including lithium ion as well as sodium ion batteries. Their high theoretical capacities are in particular due to the possibility to store more than one alkali atom per molecule. We present a density functional theory study of lithium attachment to TCNE and TCNQ. Trends in the Li binding strengths (which determines the electrode voltage) are presented between TCNE and TCNQ and a function of the number of attached Li atoms. We show that multiple Li attachment induces non-trivial changes in the electronic structure which involves electron donation to higher (than LUMO) unoccupied molecular orbitals as well as Li-centered orbitals. Strain effects induced by Li attachment lead to significant changes in the electronic structure including changes in orbital ordering. A new cyclic molecular structure stabilized by Li attachment to TCNE is identified. We conclude that design of organic electrode materials should consider the energies of higher (than LUMO) orbitals as well as effects of structural changes on the electronic structure.
9:00 PM - EE5.2.16
Ab Initio Molecular Dynamics Characterization of La-Based Perovskite-Type Oxides for Metal-Air Cell Cathodes
Aysegul Afal Genis 1,Mehmet Kadri Aydinol 1
1 Department of Metallurgical and Materials Engineering Middle East Technical University Ankara Turkey,Show Abstract
Oxygen reduction reaction (ORR) catalytic activities have been of great scientific importance for extensive studies in energy storage technologies, specifically in metal-air batteries. Metal-air batteries are promising for future applications of especially electrical vehicles due to the utilization of oxygen from the air as one of the battery’s main components. Kinetic performance of the electrochemical reaction taking place in these batteries mainly depends on the reduction of oxygen at the cathode. Different groups of catalysts have been considered in order to facilitate ORR at the air electrodes including precious metal catalysts, metal oxides and carbons. Contrary to the ORR on metals and metal alloys in acidic environments, little is known about the influence of intrinsic properties of complex oxides on their activity toward the ORR in alkaline media. To develop novel and highly active cathode materials, a deeper understanding of the correlation between the cathode material properties and ORR activity is necessary. The crucial role of electronic structure in determining the electrochemical activity has been well recognized in the field of catalysis. First-principles computational studies, in particular density functional theory (DFT) studies, have made important contributions to such efforts, identifying fundamental correlations between catalytic activity and electronic structure for different types of catalyst materials. Therefore, ab initio methods become a useful tool to characterize catalytic properties by examining electronic structures, reaction energetics and activation energies. In this study, the effect of surface crystallography on oxygen molecule dissociation and adsorption properties on different types of transition metal perovskites of the type ABO3 (A=La, B= Mn, Cr, Fe, O=oxygen) are presented. To analyze the oxygen–perovskite interaction, ab initio molecular dynamics method is used to simulate the behavior of O2 at the surface. This method is expected to show whether the transition metal elements displayed an effect of catalyzer in terms of dissociation of the O2 molecule into O atoms at the surface. A systematical study within adsorption characteristics of oxygen on La-based perovskite surfaces was performed. In addition, via ab initio molecular dynamics simulations, what kind of an effect would different planes make on oxygen behavior at the surface was studied. Ab initio molecular dynamics simulations were executed on clean low- index (001) and (111) surfaces of perovskites. Simulations were done by ab initio pseudopotential method within the generalized gradient approximation (GGA) to density functional theory (DFT).
9:00 PM - EE5.2.17
Graphene Oxide Enhanced Polyacrylonitrile Nanofiber Membrane Used as Seprator for Achieveing High-Performance Lithium-Sulfur Batteries
Jiadeng Zhu 1,Xiangwu Zhang 1
1 North Carolina State Univ Raleigh United States,Show Abstract
Sulfur has been considered as a promising cathode candidate for next generation batteries due to its high theoretical capacity and energy density. However, the severe self-discharge behavior strongly limits the practical applications of lithium-sulfur (Li-S) batteries. Here, we report a sustainable and highly porous polyacrylonitrile/graphene oxide (PAN/GO) nanofiber membrane which can be performed as a novel separator for lithium-sulfur batteries to achieve high stable capacity and excellent anti-self-discharge feature. A superior low retention loss of 5% can be obtained even after a resting time of 24 h not only due to the relatively high energy binding between –C≡N and Li2S/Li-S radicals but to the electrostatic interactions between GO and negatively charged species (Sn2-). It is, therefore, demonstrated that this GO incorporated PAN as-spun nanofiber with highly porous structure and excellent electrolyte wettability is a promising separator candidate for high-performance Li-S batteries.
9:00 PM - EE5.2.18
Influence of Fluorine Incorporation of Directly Disulfonated Copolymer Membranes on the Vanadium Redox Flow Battery (VRFB) Performance
Kenan Kara 1,Levent Semiz 1,Tunc Eren Akay 1,Erkan Aydin 1,Nurdan Demirci Sankir 1,Mehmet Sankir 1
1 Materials Science and Nanotechnology Engineering TOBB University of Economics and Technology Ankara Turkey,Show Abstract
Vanadium redox flow batteries (VRFBs) have been demonstrated as energy efficient conversion devices with long service life. Moreover, VRFBs have been assumed as highly cost effective when inexpensive membranes were utilized. The state-of-art membrane Nafion™, perfluorinated copolymer, has been the most commonly used membrane although it suffers from its high cost, lower proton conductivity and higher vanadium permeability. Therefore, much efforts has been focused on replacing Nafion™. Also there is a great interest to compare and contrast VRBF performances of both fluorinated and non-fluorinated based hydrocarbon membranes. This study focuses on the effect of fluorine moeity of directly disulfonated (35 molar %) poly(arylene ether benzonitrile) copolymer (PAEB) membranes on the VRFB performance. The fluorine incorporation from 25 to 100 molar percents has been systematically varied by using hexafluoro-isopropylidene diphenol (6F) monomer during copolymerization. It was demonstrated that efficiencies of VRBF prepared from both fluorinated and nonfluorinated copolymer membranes were better than that of N212. The columbic efficiencies of copolymer membranes not bearing any fluorine content (PAEB35) and Nafion™ were about 98.7 and 87.6 percents at the current density of 20 A cm-2, respectively. Once a 100 molar percent fluorination (6F100PAEB35) was achieved, the columbic efficiency was about 99.5, which was one of the best efficiencies reported in the literature. This trend was also observed at higher current densities. The superiority in the columbic efficiency was due to the lower vanadium permeabilities of the 6F100PAEB35 copolymer membranes (1.0 x 10-13 m2 s-1). Among the series, 6F100PAEB35 had 4-fold lower vanadium permeability than PAEB35. On the other hand the vanadium permeabilities of 6F100PAEB35 were about 8 times lower than that of N212 (1.3 x 10-12 m2 s-1). The proton conductivity of the PAEB 35 is 77 mS cm-1. As the fluorine content increased from 0 to 100 molar percent the ion exchange capacity (IEC) decreased from 1.86 to 1.31 mequiv g-1. Since, the proton conductivity and water uptake values which were function of IEC followed the same trend and decreased from 77 to 56 mS cm-1 and from 39 to 22 wt% with increasing fluorine content, respectively. Therefore voltage efficiencies of fluorine bearing copolymer membranes were slightly lower than their non-fluorinated analogous in the series. For example, the voltage efficiencies of PAEB 35 and 6F100PAEB35 were about 92.8 to 91.8 % at 80 mA cm-2, respectively. Moreover, overall efficiencies of both fluorinated (91.2 %) and nofluorinated copolymer membranes (91.6 %) were far better than N212 (80.5%). The selectivity (e.g., proton conductivity/permeability) of fluorinated series was about 3 and 20 times higher than non-fluorinated copolymer membranes and N212, respectively. These highly selective copolymer membranes have been utilized as promising candidates for VRFBs.
9:00 PM - EE5.2.19
Ternary Metal Fluorides as New High-Energy Cathodes for Rechargeable Lithium Batteries
Feng Wang 1,Sung-Wook Kim 1, Dong-Hwa Seo 2,Kisuk Kang 2,Liping Wang 1,Dong Su 1,John Vajo 3,John Wang 3,Jason Graetz 3
1 Brookhaven National Laboratory Upton United States,2 Seoul National University Seoul Korea (the Republic of)3 HRL Laboratories Malibu United StatesShow Abstract
Transition metal fluorides are promising high-capacity battery cathode for large-scale applications (i.e. electric vehicles), but issues related to low voltage, large hysteresis and limited cycling reversibility remain a major hurdle to their commercial application. Here we report on the synthesis, structural and electrochemical properties of new nanostructured ternary metal fluorides, which may overcome some of these issues. By substituting Cu into the Fe lattice, forming the solid solution CuyFe1-yF2, reversible Cu and Fe redox reactions were achieved with surprisingly small hysteresis (<150 mV). This finding indicates that cation substitution may provide a new pathway for tailoring electrochemical properties of conversion electrodes . The Li storage/release mechanisms and limits to cycling stability of CuyFe1-yF2 were also investigated by combining electrochemical measurement with comprehensive structural and chemical analysis using in-situ X-ray absorption spectroscopy, X-ray diffraction, and transmission electron microscopy-electron energy loss spectroscopy (TEM-EELS). Detailed lithium reaction mechanisms, Cu-loss related issues along with possible remedy solutions in the CuyFe1-yF2 system, will be discussed. The work was supported as part of the NorthEastern Center for Chemical Energy Storage, an EFRC Center funded by the U.S. DOE-BES, under Award Number DESC0001294, and by DOE-EERE under the Advanced Battery Materials Research program, under Contract No. DE-SC0012704.  Wang et al., “Ternary Metal Fluorides as High-Energy Cathodes with Low Cycling Hysteresis”, Nat. Commun. 6:6668 (2015).
9:00 PM - EE5.2.20
Porous 2D Transition Metal Carbides (MXenes) for High-Performance Lithium-Ion Storage
Chang Ren 1,Meng-Qiang Zhao 1,Taron Makaryan 1,Joseph Halim 1,Muhammad Boota 1,Sankalp Kota 1,Babak Anasori 1,Yury Gogotsi 1
1 Drexel Univ Philadelphia United States,Show Abstract
Introduction of well-designed micro-, meso- or macro-porous structures into functional building blocks, generally leads to significantly improved or unexpected physiochemical properties and performance. MXenes are a family of 2D transition metal carbides, which have shown great promise as electrodes in lithium-ion batteries and supercapacitors. However, the accessibility of electrolyte ions into MXenes is limited due to the compact stacking of the 2D flakes, hindering the full utilization of their energy storage performance. Herein, we successfully introduce porous structure into MXene flakes and demonstrate the significant improvement of their Li-ion storage capability.
The porous structure was introduced into MXenes by an easy and controllable chemical etching method. Typically, Ti3C2 colloidal solution was mixed with an aqueous solution of transition metal salts (e.g. CuSO4, CoSO4 or FeSO4) at room temperature while stirring for 30 min. The suspension was washed by 5 wt.% HF aqueous solution and vacuum filtered. This process resulted in a freestanding and flexible p-Ti3C2 film with large quantity of pores on Ti3C2 flakes, which enhanced its specific surface area. The electrochemical performance of p-Ti3C2 was evaluated by using p-Ti3C2/CNT composite film as anode material in Li-ion batteries. At 0.5 C, a capacity of ≈750 mAh g-1 was achieved, much larger compared to that of the non-porous Ti3C2/CNT film (≈220 mAhg-1), along with excellent cycling stability. The p-Ti3C2/CNT electrode also showed impressive rate performance. A high capacity of ≈1250 mAh g-1 was achieved at 0.1 C after a pre-cycling process, and ≈330 mAh g-1 was retained at 10 C. This chemical etching method, which is applicable to other kinds of MXenes (V2C and Nb2C), provides a simple yet effective method to improve the physiochemical properties of MXenes, and possibly other kinds of 2D materials.
Gleb Yushin, Georgia Institute of Technology
Bruce Dunn, University of California, Los Angeles
Arumugam Manthiram, University of Texas at Austin
Linda Nazar, University of Waterloo
SABIC Americas, Inc
Toyota Research Institute of North America
EE5.3/EE6.4: Joint Session: High Capacity Anodes for Rechargeable Li and Li-Ion Batteries
Wednesday AM, March 30, 2016
PCC North, 100 Level, Room 124 B
9:00 AM - *EE5.3.01/EE6.4.01
Electrodeposition of Metals in Nanostructured Electrolytes: Transport Phenomena and Stability
Lynden Archer 1
1 School of Chemical amp; Biomolecular Engineering Cornell University Ithaca United States,Show Abstract
Electrodeposition is used in various manufacturing processes for creating metal, colloid, and polymer coatings on conductive electrode substrates. The process also plays an important role in electrochemical storage technologies based on batteries, where it must be carefully managed to facilitate stable and safe operations at low operating temperatures, high rates and over many cycles of charge and discharge. A successful electrodeposition processes requires fast transport of charged species (e.g. ions, particles, polymers) in an electrolyte and stable redox reactions and transport at the electrolyte/electrode interface at which the deposition occurs. This talk considers the stability of electrodeposition of metals on planar electrodes with an emphasis on its role in enabling next-generation secondary batteries based on lithium and sodium metal anodes. Such batteries promise substantial improvements in electrochemical energy storage over todays’s state-of-the art lithium ion technology and are under active investigation worldwide.
Development of a practical rechargeable lithium metal battery (LMB) remains a challenge due to uneven lithium electrodeposition and formation of ramified denderitic electrodeposits during repeated cycles of charge and discharge. Known consequences of unstable electrodeposition in LMBs include accumulation of electrically disconnected regions of the anode or “dead lithium”, thermal runaway of the cell, and internal short circuits, which limit cell lifetime and may pose serious hazards if a flammable, liquid electrolyte is used in a LMB. Lithium-ion batteries (LIBs) are designed to eliminate the most serious of these problems by hosting the lithium in a graphitic carbon substrate, but this configuration is not entirely immune from uneven lithium plating and dendrite formation. Specifically, the small potential difference separating lithium intercalation into versus lithium plating onto graphite, means that a too quickly charged or overcharged LIB may fail by similar mechanisms as a LMB.
Using a continuum transport analysis for electrodeposition in a structured electrolyte in which a fraction of the anions are fixed in space, the talk will show that electrodeposition at the lithium anode can be stabilized through rational design of the electrolyte and salt. Building upon these ideas, the talk will explore structure and transport in novel nanoporous hybrid electrolyte configurations designed to stabilize metal anodes against dendritic electrodeposition and premature failure. Finally, the talk will explore an application of these electrolyte designs for LMBs to evaluate stability conditions deduced from theory.
9:30 AM - EE5.3.02/EE6.4.02
Practical Investigation of Silicon Oxide Anode Material for Lithium-Ion Batteries
Yeonguk Son 1,Soojin Sim 1,Hyunsoo Ma 1,Yoonkook Son 1,Suhyeon Park 1,Jaephil Cho 1
1 UNIST Ulsan Korea (the Republic of),Show Abstract
Successful strategies of silicon (Si)-based anode materials for lithium ion batteries (LIBs) have numerously reported during past decade, such as nano-designed Si structure, stronger new binder system, Si composite with other materials, and so on. However most of those strategies provided only specific energy or power density with low volumetric energy density or area capacity. The superior stability of specific energy or power density couldn’t represent the higher electrochemical performance in practical application for LIBs. To investigate the practical use of anode materials, initial area capacity of anode should be higher than 3.7 mAh/cm2 which is commercial level of graphite. It appears in high loading level that the more critical problems due to volume expansion which doesn’t appear in low loading level. Moreover, high loading level causes fast degrading of lithium metal in half-cell test. Thus electrochemical test of high loaded electrode should be conducted in a full-cell test. Therefore, here we conducted full-cell electrochemical test of Si oxide-based anode with high loading (also using only 3wt% of CMC/SBR binder) while physical mixing of LiCoO2 and Ni-rich cathode as cathode material, also known as commercialized cathode material for LIBs, and investigated its detailed fading mechanisms out to 1000 cycles.
Our investigation scope of the fading mechanism is from electrode level to atomic level. To verify the effect of electrode volume change, the thickness of electrode and solid-electrolyte-interphase (SEI) layer was measured after cycle test and chemical compositions of SEI layer were analyzed by X-ray photoelectron spectroscopy (XPS). To observe the atomic structure of electrode materials, high resolution-transmission electron microscopy (HR-TEM) were operated after long-term cycling. On the evidence of ex-situ analysis and electrochemical result, we created the algorithm for the possible fading mechanism of Si-based anode. We also separated the reasons of fast and gradual degrading respectively and suggested the behaviors of idealized Si-based anode. We believe that our findings provide a foundation to clearly verify fading mechanism of Si-based anode for LIBs and envision the considerations of future Si-based anode for practical use.
9:45 AM - EE5.3.03/EE6.4.03
Effect of Composition and Structure on Electrochemical Properties of Ternary Type I Silicon Clathrates for Lithium-Ion Battery Anodes
Candace Chan 1,Ran Zhao 1
1 Arizona State Univ Tempe United States,Show Abstract
Silicon clathrates contain cage-like structures that can encapsulate various guest atoms or molecules. Here we present an electrochemical evaluation of type I silicon clathrates based on M8YxSi46-x (M = Ba, Sr; Y = Al, Cu, Ni) as the anode material for lithium-ion batteries. For the Ba-Al-Si system, post-cycling characterization with NMR and XRD show no discernible structural or volume changes even after electrochemical insertion of 44 Li (~1 Li/Si) into the clathrate structure. The observed properties are in stark contrast with lithiation of other silicon anodes, which become amorphous and suffer from large volume changes. The electrochemical reactions are proposed to occur as single phase reactions at approximately 0.2 and 0.4 V vs. Li/Li+ during lithiation and delithiation, respectively, distinct from diamond cubic or amorphous silicon anodes. Reversible capacities as high as 499 mAh g-1 at a 5 mA g-1 rate were observed for silicon clathrate with composition Ba8Al8.54Si37.46, corresponding to ~1.18 Li/Si. These results show that silicon clathrates could be promising durable anodes for lithium-ion batteries. Changing the composition of the clathrate, namely replacing the Ba guest atom and Al framework substitution with other metals, was found to have a strong effect on the number of Li reversibly inserted into the structure and the shape of the voltage profile.
10:00 AM - *EE5.3.04/EE6.4.04
Current Status of Si-Based Anode Materials for High Capacity Li-Ion Batteries
Jaephil Cho 1
1 UNIST Ulsan Korea (the Republic of),Show Abstract
Si has been considered as a promising alternative anode for next-generation Li-ion batteries (LIBs) because of its high theoretical energy density, relatively low working potential, and abundance in nature. However, Si anodes exhibit a rapid capacity decay and increase in the internal resistance, which are caused by the large volume changes upon Li insertion and extraction. This unfortunately obstructs their practical applications. Therefore, managing the total volume change remains a critical challenge for effectively alleviating the mechanical fractures and instability of solid-electrolyte-interphase products. In this regard, in spite of many new ideas being published, all of them are still from practical implantation in the Li-ion batteries. Accordingly, it is inevitable to composite with the graphite to minimize the volume change and to balance with the cathode material. In this talk, I am going to present new advanced results of the Si and graphite composites with reversible capacity of < 600 mAh/g, which can be immediately implanted in the full cell.
10:30 AM - EE5.3.05/EE6.4.05
Limits of Energy Density in Silicon Anode Based Lithium-Ion Batteries
Ranjan Dash 1,Sreekanth Pannala 2
1 SABIC Exton United States,2 SABIC Sugar Land United StatesShow Abstract
Silicon is considered as a potential next-generation anode material for lithium ion battery (LIB). Experimental reports of up to 40% increase in energy density of silicon anode based LIBs have been reported in literature. However, such increase in energy density is achieved when silicon anode based LIB is allowed to swell more than graphite based LIB and beyond permissible limits. For practical applications such as in automotive or mobile devices, one cannot have any volume expansion. We determine the theoretical bounds of silicon composition in a silicon – carbon composite (SCC) based anode to maximize the volumetric energy density of LIB by assuming no increase in the external dimensions of the anode during charging. The porosity of SCC anode is adjusted to accommodate the volume expansion during lithiation. The determined threshold value of silicon was then used to calculate the volumetric energy densities of SCC anode based LIBs and improvement over graphite anode based LIBs for three types of cathodes - lithium cobalt oxide (LCO), lithium manganese cobalt oxide (NMC) and lithium nickel cobalt aluminum oxide (NCA), and at a constant cathode thickness of 70 μm. The maximum improvement in the volumetric capacity of SCC anode based LIB over graphite anode based LIB for LCO, NMC and NCA cathodes was determined to be ~20%, ~22%, and ~24%, respectively. Theoretical maximum in the volumetric capacity and energy density is obtained when it is assumed that there is zero porosity in the lithiated anode and that the displaced electrolyte does not need additional volume. The level of practically achievable improvements in capacity and energy density of silicon anode based LIBs is expected to be between 5-15% for lithiated anode porosities of 10-30% to ensure the battery has similar life and power characteristics of conventional LIB.
10:45 AM - EE5.3/EE6.4
EE5.4/EE6.5: Joint Session: Electrochemical Interfaces in New Battery Chemistry
Wednesday PM, March 30, 2016
PCC North, 100 Level, Room 124 B
11:00 AM - *EE5.4.01/EE6.5.01
Realization of Metal Fluoride Conversion Nanocomposite Electrodes for Batteries
Glenn Amatucci 1,Nathalie Pereira 1,Fadwa Badway 1
1 Rutgers University North Brunswick United States,Show Abstract
Metal fluoride conversion electrodes have been of fundamental interest as high energy density electrodes for lithium batteries for over 40 years, however, the theoretical electrochemical activity of such materials remained elusive as a result of their high bandgap and poor ionic and electronic charge transport characteristics. Well over a decade ago, electronically and mixed conducting matrices to form metal fluoride nanocomposites resulted in the revelation of the theoretical voltages, high energy densities, and minimal reversibility of some of the most promising fluorides and oxyfluorides which operate over 2V. Since this time many in our community have investigated these materials and advanced the state of the science significantly. This paper will discuss a sampling of the scientific, technological, and practical questions that still stand today as supported by examples of research from the community and our laboratories.
11:30 AM - *EE5.4.02/EE6.5.02
Solid State Batteries: Promise and Challenges
Nancy Dudney 1
1 Oak Ridge National Laboratory Oak Ridge United States,Show Abstract
Achieving solid state batteries that operate at room temperature is an elusive, but compelling goal, one that researchers have been working on decades. Solid state batteries hold the promise of much safer and robust energy storage, with potentially higher energy density as well. But the challenges for a thin, stable solid electrolyte with