Se-Hee Lee University of Colorado-Boulder
Akitoshi Hayashi Osaka Prefecture University
Nancy Dudney Oak Ridge National Laboratory
Kazunori Takada National Institute for Materials Science
CC1: Solid-State Batteries
Tuesday PM, April 06, 2010
Room 3011 (Moscone West)
9:30 AM - **CC1.1
Lithium Solid Electrolyte, Thio-LISICON - Structure, Ionic Conductivity and all Solid-state Batteries.
Ryoji Kanno 1 , Miki Nagao 1 , Masaaki Hirayama 1 Show Abstract
1 Department of Electronic Chemistry, Tokyo Institute of Technology, Yokohama Japan
Thio-LISICON is one of the most attractive lithium solid electrolytes for application to all solid-state batteries, because of an advantage of thermal stability over liquid electrolytes, which prevents safety hazard problem of high energy-density battery systems. From the materials viewpoint, the thio-LISICON provides a good example to study the relationship between the crystal structure and high lithium ionic conduction, and this may create new concept of material design of high ionic conducting solids based on crystal chemistry. From the viewpoint of application, the thio-LISICON is suitable for solid electrolyte of all solid-state batteries. To take advantages of “all-solid” form of the battery, we develop the batteries using sulfur as electrode material with a new electrode structure. Two or three dimensional electrode structure is a new approach for all solid-state cells to reduce interfacial resistance and to improve the utilization of active materials. These new electrodes are applied to the all solid-state battery and the reaction mechanism is studied based on the electrode structure analysis using small and wide angle diffraction measurements. New directions of all solid-state batteries will be discussed.
10:00 AM - **CC1.2
High-rate Capability of All-solid-state Batteries Using Phosphorous Sulfide Solid Electrolyte.
Yoshikatsu Seino 1 Show Abstract
1 , Idemitsu Kosan Co.,Ltd, Sodegaura Japan
We investigated high rate performance of all solid state lithium secondary batteries using LiCoO2 and LiNi0.8Co0.15Al0.05O2 coated with Li4Ti5O12 as active materials and the Li2S-P2S5 glass ceramic as a solid electrolyte. Sulfide based solid electrolyte (Li2S-P2S5 glass ceramic) were prepared by mechanical milling technique. The Li2S-P2S5 glass ceramic showed ionic conductivity as high as 4.0×10-3 S cm-1 at room temperature. The glass ceramics were highly stable against electrochemical window of 10V. Coated LiCoO2 and LiNi0.8Co0.15Al0.05O2 materials reduced an interfacial resistance between an electrode and a solid electrolyte. The high rate capability of the batteries using coated LiCoO2 and LiNi0.8Co0.15Al0.05O2 and the Li2S-P2S5 glass ceramic enhanced because of the decrease of the interfacial resistance of the batteries. The batteries using coated LiCoO2 and LiNi0.8Co0.15Al0.05O2 as an electrode and the glass ceramic as electrolyte showed a large discharge capacity of 110mAh g-1 at current density of 10mA cm-2 at room temperature. The batteries worked at high current density of 40mA cm-2 at a high temperature of 100°C. The cycle performance of the batteries using coated an electrode at high temperature of 100°C were highly stable without resistance increase after 15 cycles at the current density of 0.5mA cm-2. These results indicated providing good prospects for practical application of lithium secondary batteries free from safety issues.
10:30 AM - CC1.3
TEM Observation for Electrode/Electrolyte Interface in All-solid-state Lithium Batteries With Li2S-P2S5 Solid Electrolytes.
Akitoshi Hayashi 1 , Atsushi Sakuda 1 , Hirokazu Kitaura 1 , Motohiro Nagao 1 , Masahiro Tatsumisago 1 Show Abstract
1 Department of Applied Chemistry, Osaka Prefecture University, Sakai, Osaka Japan
All-solid-state lithium rechargeable batteries using inorganic solid electrolytes are recognized as an ultimate battery with high safety and reliability. We have developed sulfide glass-based electrolytes and found that the Li2S-P2S5 glass-ceramics exhibited high conductivity of over 10-3 S cm-1 at room temperature and wide electrochemical window. All-solid-state batteries Li-In/LiCoO2 using the Li2S-P2S5 glass-ceramic electrolytes showed excellent cyclability for 700 cycles at a limited current density. Surface coating LiCoO2 with an oxide buffer layer such as LiNbO3 and Li2SiO3 was reported to improve rate performance of all-solid-state batteries. The structure and morphology of the electrode/electrolyte interface affects the electrochemical performance of all-solid-state batteries. In this study, the solid-solid interface between LiCoO2 electrode and Li2S-P2S5 electrolyte was analyzed by TEM observation. An interfacial layer was detected by TEM at the LiCoO2/Li2S-P2S5 interface after the initial charge process. Furthermore, mutual diffusions of Co, P, and S at the interface between LiCoO2 and Li2S-P2S5 were observed. The mutual diffusion and the formation of the interfacial layer were suppressed using LiCoO2 particles coated with Li2SiO3 thin film. Interfacial structure and battery performance for several active materials including LiCoO2 will be discussed.
10:45 AM - CC1.4
A New Approach to Develop Bulk-type All Solid State Batteries.
Gaelle Delaizir 1 , Abdelmaula Aboulaich 2 , Vincent Seznec 3 , Laurence Tortet 2 , Patrick Rozier 1 , Mathieu Morcrette 3 , Virginie Viallet 3 , Renaud Bouchet 2 , Mickael Dolle 1 Show Abstract
1 , Centre d'Elaboration de Matériaux et d'Etudes Structurales, Toulouse Cedex 4 France, 2 , Laboratoire Chimie Provence, Marseille France, 3 , Laboratoire de Réactivité et Chimie des Solides, Amiens France
All solid state batteries have always been considered with a peculiar interest due to the advantages they offer, especially when safety and reliability issues are concerned. Since 1982 and the works of Hitachi Co, Ltd. Japan, thin film micro-batteries have been widely studied. However, their use remains limited to micro-electronic applications. In order to answer today’s energy needs, bulk-type all solid batteries offer higher energy densities than thin films. However, their development is limited by the difficulty to assemble laminated ceramics together as it is often very complicated to sinter sufficiently such compacts when compositions of each layer generally require different optimal sintering temperatures. The works of Hayashi et al. (Osaka Prefecture University) on bulk-type batteries based on glass-ceramic sulfide electrolyte are always under significant progress. However, the main drawback of their process remains the assembly realized by cold pressing, which brings in some limitations like the use of thin electrodes (few mg of active materials) and electrolyte.Our approach was then to develop bulk-type all solid state batteries by means of an emerging powder consolidation process: the Spark Plasma Sintering (SPS) technique. In this process, also known as Field Assisted Sintering Technique (FAST), pulsed DC current directly passes through the conducting die. Therefore, the heat is generated internally, in contrast to the conventional hot pressing, where the heat is provided by external heating elements. Such low cost process will ensure high quality contacts between materials in very short times. In this presentation, we will consider the choice of materials to develop such technology. This includes, of course, chemical and electrochemical compatibilities between electrodes and electrolyte to avoid any reaction upon the sintering process, which would affect the nature of the electrode/electrolyte interfaces and the electrochemical kinetic of the systems. The different steps to reach our goal will be detailed starting with the development of composite ceramic electrodes. Finally the electrochemical performances of half cells and full cells will be presented.
11:00 AM - CC1: SSB
11:30 AM - **CC1.5
Solid State Lithium Batteries.
Jiguang Zhang 1 , Deyu Wang 1 , Daiwon Choi 1 , Jie Xiao 1 , Wu Xu 1 Show Abstract
1 Energy & Environment Directorate, Pacific Northwest National Laboratory, Richland, Washington, United States
During the last decade, the solid state electrolyte such as Lipon (which has an ionic conductivity of 2x10-6 S/cm) developed by Bates et al 1 at Oak Ridge National Laboratory (ORNL) has been successfully used in solid state thin film batteries. The technology is ideally suited for a variety of applications where a low capacity, compact, and safe energy source is required. However, the practical application of the thin film batteries is limited by the low capacity and low energy densities of the complete thin film batteries (including substrate and package). To increase the capacity of the solid state batteries, solid state electrolyte with a conductivity of >10-3 S cm-1 has to be added to the electrode to facilitate lithium ion transfers. In most cases, electronic additive, such as carbon black, also needs to be added to the electrode to improve their electronic conductivity. Significant progresses have been made during the last two decades on the development of solid state electrolytes. For example, Bohnke et al. reported that La0.56Li0.33TiO3, which has a perovskite structure (ABO3), has a conductivity of 1x10-3 S cm-1. Thokchom et al reported a superionic glass-ceramic material (Li1+xAlxGe2−x(PO4)3, x = 0.5) with an ionic conductivity as high as 10-2 S cm-1 at room temperature. Tatsumisagoa et al 7 reported that sulfide based electrolyte exhibits an ionic conductivity of 3.9×10−3 S/cm at room temperature. Some of these solid state electrolytes have been used to prepare solid state batteries successfully 8. However, the amount of electrolyte used in these batteries still needs to be reduced to increase the practical energy density of these batteries. In this work, thick film solid state batteries using sulfide based electrolyte are further investigated. Several approaches are used to improve the practical energy density of solid state batteries. Lithium intercalation compounds which are stable with sulfide based electrolyte are used as anode. The interface resistance between solid state electrolyte and electrode is reduced by using appropriate interface layers. These high capacity solid state batteries are intrinsically safe and can be used for highly demanding energy storage applications.1.J. B. Bates, N. J. Dudney, B. J. Neudecker, F. X. Hart, H. P. Jun, and S. A. Hackney, Journal of The Electrochemical Society, 147 (1) 59-70 (2000) 59.2.Yusuke Nishio, Hirokazu Kitaura, Akitoshi Hayashi, Masahiro Tatsumisago, Journal of Power Sources 189 (2009) 629–632.
12:00 PM - **CC1.6
Fabrication of Electrode With 3 Dimensionally Ordered Structure for All-solid-state Battery.
Kiyoshi Kanamura 1 Show Abstract
1 , tokyo metropolitan university, Hachioji, Tokyo, Japan
Lithium-ion battery system is one of the most attractive energy sources for mobile devices. However, safety problem is one of the remaining issues for commercial lithium-ion batteries , because of usage of electrolytes including flammable organic solvents for lithium ion batteries. The all solid-state rechargeable lithium battery with a solid electrolyte has been recognized as one of alternative technologies. Particularly, ceramic electrolytes have been paid much attention because of their high durability against high temperature operation.However, one of the problems for all solid-state lithium-ion battery using the ceramic electrolyte is high internal resistance because of a poor contact between solid electrolyte and active material . We have proposed a novel electrode system using ceramic electrolyte with three-dimensionally ordered macroporous (3DOM) structure having a large surface area  and prepared the 3DOM electrode using Li0.35La0.55TiO3 (LLT). This electrolyte is one of high Li+ ion conductive ceramics (10-3 S cm-1 at room temperature).The 3DOM LLT electrode could be prepared by using colloidal crystal templating method. In this method, the PS beads (3 μm) suspended in water were filtered to obtain a template membrane with a opal structure, which had ideally 26% free space in volume between beads. Then, precursor sol of the solid electrolyte was injected into the free space. Finally, PS and precursor sol composite was annealed to remove the PS template and to convert the precursor sol into the solid electrolyte. Then, the macropore of the 3 DOM LLT was filled by LiMn2O4. We applied “solvent-substitution mehod” for this process. At first, the pore of 3DOM-LLT was mostly filled with sodium dodecyl sulfate (SDS) solution. The 3DOM-LLT filled with the SDS solution was immersed in the precursor sol of the active materials to inject the sol into the pore of 3DOM-LLT. The SDS solution in the macropores was replaced with Li–Mn–O sol during the immersion. After the immersion, the 3DOM LLT was annealed. The 3 DOM LLT was filled enough by the LiMn2O4 and the electrode exhibited 83 mA h g-1 of discharge capacity, 56 % of theoretical capacity (148 mA h g-1) .A suspension filtration method is another method to fabricate the 3 DOM structure. By using this method, all solid-state lithium ion batteries were fabricated. The electrochemical performance of this battery will be also presented.References J.M. Tarascon, M. Armand, Nature 414 (2001) 359. K. Hoshina, K. Dokko, K. Kanamura, J. Electrochem. Soc. 152 (2005) A2138 K. Dokko, N. Akutagawa, Y. Isshiki, K. Hoshina, K. Kanamura, Solid State Ionics176 (2005) 2345. M. Hara, H. Nakanoa, K. Dokko, S. Okuda, A. Kaeriyamaa, K. Kanamura, J Power Sources, 189 (2009) 485
12:30 PM - CC1.7
New High-conducting NASICON-like Phases on the Base of Modified Indium Phosphate.
Anna Potapova 1 , Andrey Novoselov 1 , Alexander Mosunov 2 , Galina Zimina 1 Show Abstract
1 Department of Chemistry and Chemical Engineering for Rare and Dispersed Elements, Lomonosov Moscow State Academy of Fine Chemical Technology, Moscow Russian Federation, 2 Department of Chemistry, Lomonosov Moscow State University, Moscow Russian Federation
Lithium-ion batteries are widespread practically in all fields nowadays, beginning from home appliances and finishing space equipment, thus continuously requiring researches on improvement of general efficiency, durability and reliability of materials for electrodes and electrolytes. NASICON-like complex phosphates Li3M2III(PO4)3, where MIII=In3+, Sc3+ and Fe3+, such as well-known having 3D-channel frame structure Li3In2(PO4)3, are of practical interest as high-conducting solid-state electrolytes.Looking for a new conducting material, we studied cross-section Li3In2(PO4)3-Na3In2(PO4)3 of the ternary system Li3PO4-Na3PO4-InPO4 at 950°C. The following NASICON-like solid-solutions were found: α-Li3-xNaxIn2(PO4)3 (0≤x≤0.01) on the base of high-temperature β-modification of Li3In2(PO4)3, β-Li3-xNaxIn2(PO4)3 (0.05≤x≤0.1) and LixNa3-xIn2(PO4)3 (0.9≤x≤1.0) on the base of NASICON-like Na3In2(PO4)3. Stabilizing of low-temperature Li3In2(PO4)3 β-phase with Na-ions was established. To enhance ionic conductivity, heterovalent substitution of Li and Na by Ti and Zr was performed. It allows increasing mobility of the conducting ion (Li+) and monitor structure evolution. Ionic conductivity of the obtained phases was studied with impedance spectroscopy and activation energies were calculated. Ionic conductivity of α-Li3In2(PO4)3 and β-Li3In2(PO4)3 was measured to be around 10-3 S/cm, while that of heterovalent-substituted samples was increased up to 10-1 S/cm making them promising solid-state electrolytes.
12:45 PM - CC1.8
Advances in All-solid-state Rechargeable Lithium-ion Battery Research.
James Trevey 1 , Se-Hee Lee 1 Show Abstract
1 Mechanical Engineering, University of Colorado, Boulder, Colorado, United States
Rechargeable lithium-ion batteries prevail as the world’s most preferred energy storage device due to extremely high theoretical energy densities. Advances in research and technology have lead to high performance lithium-ion batteries capable of long cycle life and high capacity. Their high potential even makes them the most prospective battery for use in hybrid and plug-in hybrid electric vehicles. Lithium-ion batteries however, contain a liquid electrolyte that is hazardous and flammable. One solution to this hazard is to move to an all-solid-state construction of lithium-ion batteries that guarantees higher levels of safety. In the past, solid state electrolytes were known for electrochemical instability with the active materials, responsible for fast capacity fading and diminishing ionic conductivity. Today, research is finding all-solid-state rechargeable lithium ion batteries that can achieve superior performance capabilities without excessive safety issues. Relatively high conductivities, improved interfacial stability, and use of a large variety of solid electrolyte materials are just a few attributes of all-solid-state batteries that make them favorable for future design.This research presents advances involving nano-silicon as and anode material and Li(Ni1CoAl)1/3O2 (L333) as a cathode material in all solid state batteries with a Li2S-P2S5 based solid electrolyte. The optimization of nano-silicon electrodes as part of an all-solid-state cell has revealed numerous complications beyond that of liquid electrolyte based cells with the same material. While the use of nano-silicon reduces the effects of volume expansion stress imposed by lithiation, it also creates a higher surface area of particle that induces reactions that are non-conducive to lithium-ion transport. Precise control of material ratios of solid electrolyte, active material, and conductive additives as well as employment of good dispersion throughout the composite electrode has shown to have positive effects on the performance of anodes. Interfacial reactions between solid-electrolyte materials and lithium metal responsible for a high degree of inconsistency within all-solid-state rechargeable lithium-ion batteries have also been minimized by advances in solid electrolyte materials selection and synthesis. And while LiCoO2 has always proven reliable, L333 is emerging as a more interesting cathode material due to its exceptionally high theoretical capacity, excellent cycle life, and stability at high voltages. Current research provides only limited data with respect to L333 involvement in all-solid-state cells because of a substantial side reaction with current solid electrolyte materials. Successful construction of solid-electrolyte materials for use with L333 relies on a double layer electrolyte layer, and further research on solid electrolytes will yield a material that will be stable to both cathode and anode materials.
CC2: 3-D Batteries
Tuesday PM, April 06, 2010
Room 3011 (Moscone West)
2:30 PM - **CC2.1
Small Footprint Microbatteries Based on Three-dimensional Architectures.
Bruce Dunn 1 , Jane Chang 2 , C. Kim 3 , Sarah Tolbert 4 Show Abstract
1 Materials Science and Engineering, University of California at Los Angeles, Los Angeles, California, United States, 2 Chemical and Biomolecular Engineering, University of California at Los Angeles, Los Angeles, California, United States, 3 Mechanical and Aerospace Engineering, University of California at Los Angeles, Los Angeles, California, United States, 4 Chemistry and Biochemistry, University of California at Los Angeles, Los Angeles, California, United States
Three-dimensional battery architectures offer a new approach for miniaturized power sources. The defining characteristic of 3-D battery designs is that transport between electrodes remains one-dimensional (or nearly so) at the microscopic level, while the electrodes are configured in non-planar geometries. Such configurations offer certain advantages, with one of the most attractive being the prospect of achieving high energy and power density within a small footprint area. These features are particularly important for integrated microsystems where the available area for the power source is limited to millimeter dimensions.The present paper reviews recent advances in the development of 3-D microbatteries which incorporate periodic electrode arrays. The design rules for such 3-D battery architectures have been established and methods for fabricating electrode arrays have been developed for a variety of materials. Our electrode array fabrication method for 3-D lithium-ion systems involves the combination of silicon micromachining with colloidal processing of electrode powders. Another key element in our 3-D battery designs is the use of a conformal electrolyte coating. Our progress in these areas will be reviewed along with a discussion of both the advantages offered by 3-D architectures and the challenges facing this technology.
3:00 PM - CC2.2
A New Nanostructured Li2S/Silicon Rechargeable Battery With High Specific Energy.
Matthew McDowell 1 , Yuan Yang 1 , Ariel Jackson 1 , Yi Cui 1 Show Abstract
1 Materials Science and Engineering, Stanford University, Stanford, California, United States
Silicon and sulfur have among the highest theoretical specific capacities as anode and cathode materials, respectively, in Li-ion batteries. However, the use of these materials has been prevented in commercial Li-ion batteries due to a variety of problems, including structural changes and volume expansion during reaction. In addition, most studies on sulfur-based lithium batteries utilize metallic lithium as the anode, which is not practical due to safety issues relating to dendrite formation at the lithium surface. We report a novel lithium-ion battery consisting of a Li2S/mesoporous carbon composite cathode and a silicon nanowire anode that overcomes many of these issues. This new battery yields an ultrahigh theoretical specific energy of 1550 Wh kg-1, which is four times that of the theoretical specific energy of existing lithium-ion batteries based on LiCoO2 cathodes and graphite anodes. The nanostructured design of the Li2S/mesoporous carbon composite cathode serves to improve electronic conductivity and to limit lithium polysulfide dissolution into the electrolyte, which results in good performance compared to previous research on Li2S electrodes. On the anode side, the silicon nanowire architecture allows for the requisite volume expansion during alloy formation without pulverization; silicon nanowires have been shown to significantly improve capacity retention with cycling. By combining these electrodes in full battery cells, we have experimentally realized a high initial specific energy of 630 Wh kg-1 based on the mass of the active electrode materials. Our Li2S/Si battery concept, which does not incorporate unsafe lithium metal, offers significant safety advantages over the Li/S battery and could have a large impact on applications such as vehicle electrification and portable electronics.
3:15 PM - CC2.3
Effect of Ionically Conductive Coatings on Electrochemical Behavior of Li+ Insertion Materials.
Chunmei Ban 1 , Dane Gillaspie 1 , Zhuangchun Wu 1 , YoonSeok Jung 1 , Anne Dillon 1 Show Abstract
1 Chemical and Materials Science Center, National Renewable Energy Laboratory, Golden, Colorado, United States
Due to increasing demand for the development of rechargeable Li-ion batteries for the transportation sector, safety and thermal stability of electrode materials currently constitute a significant research effort. Inferior electrochemical performance and unstable side reactions of electrode materials often result from surface reactions including: electrolyte decomposition, the formation of a solid-state interface, and cation-dissolution from electrode materials. Side reactions on nanoscale materials are, of course, more severe because of increased surface area. Therefore, chemical modification of electrode surfaces is currently being extensively studied. Furthermore, sustainable and safe cycling has been demonstrated by depositing thin surface coatings of inert materials such as Al2O3 or ZrO2 as well as conductive materials including carbon. However, there has been limited research on surface treatments of ionic conducting materials such as LiAlF4, beta-alumina etc. The goal of this work is to understand how an ionic conducting coating may protect electrode materials in order to improve Li-ion battery performance. Thermal evaporation, pulsed laser deposition as well as atomic layer deposition may be employed to coat various Li-ion battery electrodes. The effect of ionic-conductive coatings to improve electrochemical performance will be discussed in detail here.
3:30 PM - CC2.4
LiCoO2 Vapor Synthesis by RF-magnetron Sputtering Approach Towards Rechargeable 3-D Thin-film Lithium Battery.
Yoongu Kim 1 , Nancy Dudney 1 Show Abstract
1 , Oak Ridge National Lab, Oak Ridge, Tennessee, United States
Three dimensional (3-D) thin-film battery structures are very attractive because they have higher energy storage per footprint area than current 2-D thin-film battery structures . Trench structures on a silicon wafer are one candidate of 3-D structures that can be simply fabricated by a microelectronics process . Bates et al. indicated that LiCoO2 films synthesized on a planar substrate facing the source are grown to preferential (101) and (104) crystal orientations . The film texture and microstructure enables rechargeable thin-film lithium batteries to provide a high-rate cycling behavior. LiCoO2 vapor synthesis on a trench structure, however, may provide quite different film properties that impact the battery performance. This research reports LiCoO2 film depositional properties on a trench structure by a RF-magnetron sputtering approach. Using a Direct Simulation Monte Carlo (DSMC) simulation, we will explore sputtering natures of LiCoO2 film properties on a trench structure.References Jeffrey W. Long, Bruce Dunn, Debra R. Rolison and Henry S. White, Chem. Rev. 104 (2004) 4463-4492. Loic Baggetto, Rogier A. H. Niessen, Fred Roozeboom and Peter H. L. Notten, Adv. Funct. Mater. 18 (2008)1057-1066. J. B. Bates, N. J. Dudneys, B. J. Neudecker, F. X. Hart, H. P. Jun and S. A. Hackney, J. Electrochem. Soc. 147 (2000) 59-70.Acknowledgement: Research sponsored by the Division of Materials Sciences and Engineering, U.S. Department of Energy
3:45 PM - CC2.5
Solid State 3D Li-ion Battery Based on Cu2Sb Nanowire Arrays.
James Mosby 1 , Derek Johnson 1 , Timothy Arthur 1 , Jacob Kershman 1 , Daniel Bates 1 , Amy Prieto 1 Show Abstract
1 Chemistry, Colorado State University, Fort Collins, Colorado, United States
Lithium-ion batteries have become the primary energy choice for low power applications, and are now being sought after for high power applications in hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV), and electric vehicles (EV). To be successful in the high-power market, the short comings that have confined the use of conventional Li-ion batteries to low-power applications need to be addressed. We are in the process of fabricating an all solid-state Li-ion battery that mitigates the safety issues inherent in conventional Li-ion batteries. This is accomplished by using a non-carbon based anode material, Cu2Sb, that lithiates sufficiently above the potential for metallic lithium dendrite growth; thereby mitigating the potential for fire. We have successfully fabricated thin film half and full cells using electrodeposited Cu2Sb as the anode material, an electrochemically grown electrolyte, and various cathode materials. Preliminary cycling performance of these solid-state thin film batteries will be presented to demonstrate the usefulness of the fabrication process. Unfortunately, solid-state diffusion limits the deliverable power of a solid-state battery and is thus the most important performance characteristic that must be overcome in order for solid-state Li-ion batteries to be used in electric powered vehicles. We are designing a high surface area, three dimensional (3D) solid-state battery based on an array of Cu2Sb nanowires with average diameters of 40 nm. The nanowires are coated with a solid electrolyte, and the void space between the wires is filled with nanoparticles of cathode material. A battery based on this 3D nanoscale morphology will benefit from a shorter diffusion distance for the lithium ions and a three orders of magnitude increase in the active materials specific surface area. These two properties are predicted to provide higher power output then conventional non-solid state Li-ion batteries. The third short coming of traditional Li-ion batteries for use in electric powered vehicles is cost. For this reason, the fabrication process of the 3D nanowire battery is based on (1) electrodeposition of the Cu2Sb from aqueous solution, (2) electrochemical formation of the electrolyte onto these wires, and (3) dip casting the cathode nanoparticles between the Cu2Sb nanowires. None of these processes require high vacuum, high temperature processes or expensive equipment, thereby reducing the overall cost of the battery fabrication in comparison to traditional manufacturing costs. The issues that are currently being addressed in the fabrication process of an all solid-state 3D battery based on nanowires arrays of Cu2Sb will be discussed, along with some preliminary results of the first generation prototype.
4:30 PM - **CC2.6
Thin Film Solid-state Batteries for Micro-energy Sources Fabricated by PLD.
Naoaki Kuwata 1 Show Abstract
1 IMRAM, Tohoku University, Sendai, Miyagi, Japan
Thin film batteries (TFB) have extensive potential uses as energy sources for micro-devices. Thin film solid-state battery consists of three thin film layers; both positive and negative electrodes and a solid electrolyte. Key material for the TFB is the solid electrolytes, which should have a high Li+ ion conductivity, electrochemical stability and a good contact with electrode interfaces. We have been challenged to fabricate TFB components, especially solid electrolytes, by pulsed laser deposition (PLD). PLD technique provides several advantages; (i) conserving the stoichiometry, (ii) small contamination, (iii) high deposition rate, etc. An ArF excimer laser operating at 193 nm, a forth harmonic of Nd:YAG laser operating at 266 nm and a XeCl excimer laser operating at 308 nm were used for ablation. For the target materials, several lithium oxides, such as lithium phosphate, Li-V-Si-O, lithium silicate, lithium sulfate, lithium borate, Ohara glass ceramics etc. were used. The morphology, roughness and crytallinity of the thin film depend strongly on the laser wavelength. We found that the photon energy is the most significant parameter on the film quality, because the band gap absorption is the most important interaction between laser and target materials. All-solid-state thin-film batteries consisting of the LVSO solid electrolyte, crystalline lithium cobalt oxide cathode and amorphous tin oxide anode were fabricated by using only PLD technique. The TFB can operate at potential between 0 to 3.5 V and shows a good reversibility on cycling over 100 cycles. However, the LVSO film cannot use a Li metal anode due to the reduction of vanadium. On the other hand, the lithium phosphate film is stable with contact to the lithium metal. All-solid-state thin film battery, Li/Li3PO4/LiCoO2, shows excellent electrochemical property in the potential range from 3.0 to 4.4 V. The thin film battery also shows extremely long cycle life and the charge-discharge curve is almost identical to the initial one after 1000 cycles. It is shown that PLD is a useful technique for preparation of the solid electrolyte thin film lithium ion conductors which can be used as a solid electrolyte in rechargeable thin film lithium batteries.
5:00 PM - CC2.7
Electromechanical Probing of Li-Activity on the Nanometer Scale in Cathode Materials.
Nina Balke 1 , Stephen Jesse 1 , Anna Morozovska 2 , Eugene Eliseev 2 , Ding-Wen Chung 3 , Edwin Garcia 3 , Yoongu Kim 1 , Leslie Adamczyk 1 , Nancy Dudney 1 , Sergei Kalinin 1 Show Abstract
1 , Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States, 2 , National Academy of Science of Ukraine, Kiev Ukraine, 3 , Purdue University, West Lafayette, Indiana, United States
The electrochemical energy storage systems based on Li-based insertion and reconstitution chemistries are a vital aspect of energy technologies. A distinctive feature of these systems is a significant change of molar volume, which can be as large as tens of percent, during electrochemical processes. This expansion is highly anisotropic; e. g., in LiCoO2 it is the most pronounced in the c-axis direction and smallest in the direction of the CoO2 layers. Here, the strong strain-bias coupling in electrochemical materials is used to develop the capability for mapping electrochemical reactions on the nanometer scale, and hence get insight into the mesoscale mechanisms of battery operation. The Scanning Probe Microscopy tip concentrates a periodic electric field in a nanoscale volume of material, resulting in Li-ion redistribution. The associated changes in molar volume result in local surface expansion and contraction that is transferred to the Scanning Probe Microscopy probe and detected by microscope electronics. The simple estimates suggest that the extremely high (~3-10 pm) sensitivity of dynamic Atomic Force Microscopy potentially allows detecting Li concentration change of 10% in ~300 nm3 volumes, exceeding the state of the art by 6-9 orders of magnitude. Finally, with dc fields applied to the Scanning Prope Microscopy tip, the Li concentration underneath the tip can be changed and hysteretic strain loops related to electrochemical charge-discharge processes can be measured. Theoretical calculations are shown to support the experimental data and to give insight into the signal generating mechanism. This material is based upon work supported as part of the Fluid Interface Reactions, Structures and Transport (FIRST) Center, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number ERKCC61 (Y.K., S.J., L.A., N.D., S.V.K.). N.B. acknowledges the Alexander von Humboldt foundation for financial support. R.E.G. and D.W.C. thank the support provided by NSF grant CMMI 0856491.
5:30 PM - CC2.9
Printable Ag2O Cathodes for Silver-Zinc Batteries.
Kyle Braam 1 , Steven Volkman 1 , Vivek Subramanian 1 Show Abstract
1 Electrical Engineering, University of California, Berkeley, Berkeley, California, United States
Printed batteries are attractive due to their low potential cost of fabrication. In particular, printed batteries are being pursued for a range of low-cost electronics applications due to the ease of integration that printing provides. The silver-zinc battery system is attractive for printing because of the high energy density and air stability that this system offers, allowing for ease of processing. While this system is often considered too expensive for bulk battery applications, the low-material consumption for typical printed electronic cells makes the processing cost the dominant cost; as a result, printed silver-zinc batteries appear to be good candidates for these applications. For printed battery applications, the availability of high-quality printed electrodes offering good discharge capacity is critical to realizing high energy-density cells. We present an investigation of a printed Ag20 cathode consisting of Ag20 particles with polyvinyl alcohol (PVA) as a binding material. This mixture is easily formulated into an ink or slurry suitable for printing using a wide range of printing techniques. Here, we print cathodes using extrusion printing. The printed Ag20 cathodes are characterized with X-ray diffraction, charge-discharge measurements, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) to determine the impact of cathode microstructure and chemical composition on electrical performance. In pure Ag2O/PVA cathodes, SEM and XPS results indicate a porous connected network of Ag2O is formed with a thin PVA coating. We note a drastic decrease in discharge efficiency, particularly as we increased the discharge rate, due to nonuniform conductivity in the film, leading to Ag20 domains in the film. To achieve dramatically improved utilization, we formulate cathode inks consisting of Ag2O, PVA, and acetylene black. The acetylene black mitigates the effect of the PVA binder and improves discharge efficiency, achieving a 97% discharge capacity at a C1 rate. Thus, this optimized cathode structure represents an excellent cathode for printed silver-zinc battery applications.
5:45 PM - CC2.10
Li-ion Diffusion Coefficients and Kinetic Behavior in Li4Ti5O12 Thin Film Electrode.
Jianqiu Deng 1 , Zhouguang Lu 1 , Chiyuen Chung 1 Show Abstract
1 Department of Physics & Matetrials Science, City University of Hong Kong, Kowloon, Hong Kong, China
Anode Li4Ti5O12 thin films were deposited on Pt/Ti/SiO2/Si substrates by pulsed laser deposition (PLD). The microstructure and morphology of the films were characterized by XRD and SEM. The lithium-ion chemical diffusion coefficients DLi were determined by cyclic voltammetry (CV), galvanostatic intermittent titration technique (GITT), potentiostatic intermittent titration technique (PITT), and electrochemical impedance spectroscopy (EIS). The DLi values depended on the content of Li in Li4/3+xTi5/3O4. The DLi values derived by different methods were in the range of 10−9–10−13 cm2 s−1. The kinetic parameters obtained from impedance plots and the variations of DLi values as a function of cell voltage were correlated with the electrochemical performance in thin film electrodes with different thicknesses. The decreases of the DLi value and charge-transfer resistance (Rct) during discharge process explained the particle of Li4Ti5O12 is a core-shell structure in the system of coexistence of two phases, i.e. Li7Ti5O12 (shell)/Li4Ti5O12 (core) during the lithiation process and Li4Ti5O12 (shell)/Li7Ti5O12 (core) during the delithiation process.
Se-Hee Lee University of Colorado-Boulder
Akitoshi Hayashi Osaka Prefecture University
Nancy Dudney Oak Ridge National Laboratory
Kazunori Takada National Institute for Materials Science
CC3: Nanostructured Materials
Wednesday AM, April 07, 2010
Room 3011 (Moscone West)
9:30 AM - **CC3.1
Electrode Architectures for Enhancing Energy Density in Rechargeable Lithium Batteries.
Yet-Ming Chiang 1 , Can Erdonmez 1 , Wei Lai 2 , Chang-Jun Bae 1 Show Abstract
1 Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States, 2 Chemical Engineering and Materials Science, Michigan State University, East Lansing, Michigan, United States
It is well-known that the comparatively poor volumetric and gravimetric utilization of active materials in current lithium ion batteries originates from the need for thin laminate electrodes to provide adequate kinetics, the use of additives that contribute no charge storage such as conductive carbon and polymer binders, and the contributions from current collectors, separators, tabs, electrolyte, and external packaging. Attempts to increase electrode thickness and density in conventional designs have met diminishing returns due to electronic, ionic, or interfacial charge transport limitations that decrease the rate at which the active material can be utilized.Here we demonstrate an alternative electrode architecture consisting of thick, sintered, three-dimensionally porous, high-density oxide cathodes. These electrodes have ample electronic conductivity in the complete absence of conductive additives, adequate electrolyte-phase conductivity due to the low tortuosity of the available porosity compared to conventional calendared electrodes, and are surprisingly tolerant of the substantial cyclic volume changes and Vegard stresses associated with electrochemical cycling of intercalation compounds. Typical cathodes based on LiCoO2 are 0.26mm to 0.80mm thick, have 74% to 87% sintered density, and provide nearly 10 times the capacity per unit area of conventional lithium ion electrodes. We demonstrate the use of these electrodes in high energy density rechargeable batteries of various size scales and form factors.
10:00 AM - CC3.2
MWCNTs-supported LiFePO4 Synthesized by an in-situ Hydrothermal Route With High-rate Performance.
Hongming Yu 1 , Jian Xie 1 , Gaoshao Cao 1 , Yuanli Ding 1 , Xinbing Zhao 1 Show Abstract
1 Materials Science and Engineering, Zhejiang University, HangZhou, Zhejiang, China
Olivine-type lithium iron phosphate is of increasing interest as a promising cathode material for large size lithium-ion batteries that will be used in electric vehicles and standby power sources from both economic and safety points of view. The main drawback for this material is its low electronic conductivity and low Li-ion diffusion rate, which result in poor rate capability and low lithium utilization in its host structure. Reducing materials dimensions and coating carbon have been considered to be effective to solve these problems. Here we develop a strategy of synthesizing MWCNTs(multi-wall carbon nanotubes)-supported LiFePO4 composites by in-situ hydrothermal route with activiated CNTs. We find that nano-sized LiFePO4 particles grow surrounding CNTs with a narrow size distribution. The CNTs dispersed uniformly enbeded in the aggregates and built up a net work which inhibit the crystal growth in the following annealing. Galvanostatic charge-discharge test was performed. The composites exhibited a high specific capacity of 160 mAh g-1 at 0.1C rate and 140mAh g-1 at 10C rate. The cycling performance at 10C rate showed a retention rate of 90% after 200 cycles. The good electrochemical performance can be attributed to the intimate contact between MWCNT and LiFePO4 particles, which significantly enhances the electrical conductivity of the material. The addition of MWCNT can also reduce the size of LiFePO4 particles even after thermal treatment, which can increase the Li-ion diffusion rate as proved by the EIS results. This method provides an effective way to obtain high rate performance of cathode material LiFePO4.
10:15 AM - CC3.3
Improvement of the Electrical Conductivity of LiFePO4 Without Carbon Conductors.
Sungbin Park 1 , Ho-Chul Shin 2 , Chang-Kyu Park 1 , Wan-Gyu Lee 1 , Won-Il Cho 2 , Ho Jang 1 Show Abstract
1 Materials Science & Engineering, Korea University, Seoul Korea (the Republic of), 2 Battery Center, Korea Institute of Science and Technology, Seoul Korea (the Republic of)
The LiCoO2 cathode has been widely used in commercial portable power sources because of easy fabrication, good electrochemical performance with reasonable capacity. However, HEV application of the LiCoO2 has been limitted due to its high cost and safety related issues inducing researchers to find alternatives. During the last decade, much efforts have been made to replace the LiCoO2 with new materials such as LiMn2O4, LiNiO2, LiFePO4, and their derivatives. Among them LiFePO4 has attracted great attention as a fascinating candidate because of low cost, high capacity, and excellent structural and thermal stability compared to LiCoO2. However, the full scale commercilization of LiFePO4 has been very limmited since it is a polaronic insulator. To overcome low electrical conductivity, transition metal substitution and carbon coating techniques are currently used. Conventional carbon coating methods need addtional carbon sources such as carbon black, graphite to coat the surface of LiFePO4 particles. In this study, without employing additional carbon sources, carbon coated LiFePO4 was obtained using acetone during mechanochemical reaction. The improvment of electrochemical performance was also achieved as an alternative method to produce carbon on the LiFePO4 particle surface. Results show that the capacity retention of the wet-milled LiFePO4 was higher than that of dry-milled LiFePO4 with similar initial capacity and high rate performance was also improved. The UV spectroscopy showed an evidence of dissolving the FeC2O4_2H2O by acetone. The EGA results indicated that the generation of CO gas from wet milled LiFePO4 was higher than that of the dry milled LiFePO4. The CO gas was generated by oxygen deficiency during the synthesis and resulted in residual carbon generation.
10:30 AM - CC3.4
Engineering LiAlSiO4 via Atomic Layer Deposition for the Electrolyte Material in Lithium Micro-batteries.
Ya-Chuan Perng 1 , Carissa Eisler 1 , Nick Cirigliano 2 , Daniel Membreno 2 , Jane Chang 1 , Bruce Dunn 2 Show Abstract
1 Chemical Engineering, UCLA, Los Angeles, California, United States, 2 Materials Science and Engineering, UCLA, Los Angeles, California, United States
As electronic devices continue to shrink in size, the demand for power sources and batteries with higher power densities and smaller footprint has increased dramatically. Lithium-ion batteries are of great interest at the micrometer-scale because of their higher energy density and reliability compared to other micro-batteries. Lithium aluminasilicate (LiAlSiO4) is an attractive electrolyte material for these batteries because of its high ionic conductivities at elevated temperatures, attributed to their unique crystalline structure. The aluminum (Al)- and silicon (Si)- oxygen (O) tetrahedrals form channels along the c-axis of the crystal where the lithium ions reside, and these channels allow for one-dimensional and efficient diffusion of lithium ions. Since the ionic conductivity typically increases as a result of decreasing the film thickness, this makes the ultra-thin electrolyte layers ideal for micro-batteries. Atomic layer deposition (ALD) was employed in this work to deposit the lithium aluminasilicate electrolyte, which has been employed to deposit solid oxide electrolytes onto fuel cells. In addition, the self-limiting characteristics of ALD offers thickness and composition controls for complex oxide growth with limited pinholes and a highly conformal coating over high aspect-ratio features. The metal precursors used in this work are tetraethyl orthosilicate (TEOS), trimethylaluminum (TMA), lithium t-butoxide (LTB) and tri-t-butoxy-hydroaluminate (LTBA), along with the water vapor as the oxidant, to deposit SiO2, Al2O3, Li2O and LiAlO2 deposition, respectively. By varying the number of ALD cycles for each oxide, the ratio of the three metal elements, Li, Si and Al, in the lithium aluminasilicate film was controlled to create the optimal composition for the maximum Li-ion conductivity. A variety of analysis techniques was used to verify the deposition of lithium alumina silicate by ALD, including x-ray photoelectron spectroscopy (XPS), ultraviolent photoelectron spectroscopy (UPS), NMR , ICP-MS and X-ray diffraction (XRD) . The growth rate of pure SiO2, Al2O3 and Li2O was measured by the Woolam M-88 spectroscopic ellipsometer to be 2Å/cycle, 1.1Å/cycle and 0.8Å/cycle, respectively. The incubation time of growing one oxide material on the other depends on the starting surface and has to be accounted for in controlling the thin film stoichiometry. The concentration of each metal element in a given thin film is found to correlate closely to ALD cycles and the incubation times, as confirmed by XPS and synchrotron UPS. The Li-ion conductivity of all ALD synthesized LiAlSiOx was determined by impedance measurements with Hg and graph foil as the electrodes, and it was found that the ion conductivity is dictated by not only the Li content but also the ALD deposition sequence, which defines the location and local environment of the Li-conducting channels.
10:45 AM - CC3.5
WITHDRAWN 4/1/10 Nanoporous Hollow Spheres of Metal Oxides for Li-ion Rechargeable Batteries.
Ming Au 1 , Thad Adams 1 Show Abstract
1 , Savannah River National Laboratory, Aiken, South Carolina, United States
Currently, carbon base anodes are being used for Li-ion rechargeable batteries through Li ion intercalation process. The theoretic capacity is limited at 372 mAh/g. The volume expansion and breakdown of solid electrochemical interface (SEI) of carbon anodes during overcharging is one of the reasons of thermal runaway and fire ignition. Searching for new anode materials that possess high energy density, high power density, low cost and inherent fire safety is not only scientist’s passion, but also the mandate of industries and consumers, particularly for plug-in hybrid vehicles and portable power sources.It is known that metal oxides can host Li ions through a conversion process that changes the lattice structure of metal oxides. The theoretic capacity of metal oxides is in the range of 500 ~ 1000 mAh/g. The metal oxides do not react with polymer electrolyte resulting in excessive heat. Rather than metal anodes that generate 200-300% volume expansion during conversion, the volume of the most of metal oxides will shrunk when they are reduced by lithium ions in conversion process. This feature will bring less strain to materials and prevent them from pulverization. However, the metal oxides generally have poor electronic conductivity. The conductive additives have to be used. The porous metal oxides with stable structural integrity will over come these obstacles by providing more access sites for Li ions shuttling and maintaining reliable electric contact with additives. In this paper, we will discuss our effort and the results in developing of porous and stable metal oxide anode materials for high capacity lithium-ion rechargeable batteries with an excellent cyclability.
11:15 AM - **CC3.6
Improving the Performance of Li Ion Batteries Using Atomic Layer Deposition.
A. Cavanaugh 1 , Y. Jung 2 , A. Dillon 4 , M. Groner 5 , Steven George 3 Show Abstract
1 Chemistry and Chemical Engineering, University of Colorado, Boulder , Colorado, United States, 2 Physics, University of Colorado, Boulder, Colorado, United States, 4 , National Renewable Energy Laboratory, Golden, Colorado, United States, 5 , ALD NanoSolutions, Inc., Broomfield, Colorado, United States, 3 Mechanical Engineering, University of Colorado, Boulder , Colorado, United States
Atomic layer deposition (ALD) coatings have been found to enhance the performance of Li ion batteries. Cathodes prepared using LiCoO2 powders coated with Al2O3 ALD films exhibited higher stability. The capacity retention was 89% after 120 charge-discharge cycles in the 3.3-4.5 V (vs. Li/Li+) range compared with bare LiCoO2 powders that displayed only a 45% capacity retention. Al2O3 ALD films coated directly graphite electrodes also displayed dramatically improved performance and 98% capacity retention was observed after 200 charge-discharge cycles. Other Li-containing ALD films may also provide performance improvement. The ALD of an artificial solid electrolyte interphase (SEI) layer may limit lithium loss and also improve the capacity stability during charge-discharge cycles. LiOH and Li2CO3 ALD films have been grown using lithium tert-butoxide, H2O and CO2. ALD film growth was monitored with a quartz crystal microbalance and the film identities were confirmed using Fourier transform infrared and x-ray photoelectron spectroscopies.
11:45 AM - CC3.7
Molecular Layer Deposition Fabricated Thin Film Electrolyte Materials for Li-ion Batteries.
Arrelaine Dameron 1 , Robert Tenent 1 , Younghee Lee 2 , Andrew Cavanagh 3 , Byunghoon Yoon 2 , Chunmei Ban 1 , Steven George 2 4 , Anne Dillon 1 Show Abstract
1 , National Renewable Energy Laboratory, Golden, Colorado, United States, 2 Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado, United States, 3 Department of Physics, University of Colorado, Boulder, Colorado, United States, 4 department of Chemical and Biological Engineering, University of Colorado, Boulder, Colorado, United States
Thin-film polymeric electrolyte scaffold materials were fabricated by molecular layer deposition (MLD) techniques and doped with Li ions by in-situ MLD and ex-situ solution techniques. MLD, similar to atomic layer deposition (ALD), is a technique to deposit surface-conformal thin-films via sequential, self-limiting vapor-solid phase reactions. This technique leads to exceptional control over the thickness and chemical composition of the polymeric electrolyte scaffold. Li ions were integrated into the scaffold by periodic doping using a t-butyl lithium precursor during scaffold growth, as well as by solution intercalation after scaffold fabrication. Thin-film growth and the degree of Li doping were monitored by x-ray reflectivity, x-ray photoelectron spectroscopy, and Fourier transform spectroscopy and cyclic voltammetry. Li ion conduction was measured by impedance spectroscopy.
12:00 PM - CC3.8
Atomic Layer Deposition For Highly Durable Li-ion Battery.
Yoon Seok Jung 1 , Andrew Cavanagh 2 , Anne Dillon 1 , Markus Groner 3 , Steven George 4 , Se-Hee Lee 5 Show Abstract
1 , National Renewable Energy Laboratory, Golden, Colorado, United States, 2 Department of Physics, University of Colorado at Boulder, Boulder, Colorado, United States, 3 , ALD Nanosolutions Inc., Broomfileld, Colorado, United States, 4 Department of Chemistry and Biochemistry and Department of Chemical and Biological Engineering, University of Colorado at Boulder, Boulder, Colorado, United States, 5 Department of Mechanical Engineering, University of Colorado at Boulder, Boulder, Colorado, United States
Lithium ion batteries (LIBs) are now considered the main energy storage device for next-generation hybrid electric vehicles and/or plug-in hybrid electric vehicles. Among many requirements for those applications, long-term durability while operating at realistic temperatures (5000 charge-depleting cycles, 15 year calendar life, -46oC - +66oC) without any catastrophic failure remain as significant challenges. The cycle life and safety issues have been largely satisfied for LixMO2 (M = Co, Ni, Mn, etc.) cathodes by coating the active materials. In these cases the coating was applied with ‘sol-gel’ wet-chemical methods.
Atomic layer deposition (ALD) is a well established method to deposit conformal thin films using sequential, self-limiting surface reactions. In spite of its many advantages over ‘sol-gel’ (conformal coating, atomic-level thickness control, no solvent, etc), the use of ALD films for LIB electrodes has not been pursued extensively.
Conformal Al2O3 thin films were deposited on LiCoO2 and natural graphite (NG) serving as commercialized cathode and anode, respectively. The Al2O3 ALD-coated LiCoO2 powders coated with 2 ALD cycles (~3-4 Å thick) exhibited a capacity retention of 89% after 120 charge-discharge cycles between 3.3-4.5 V (V vs. Li/Li+). In contrast, the bare LiCoO2 powders displayed only a 45% capacity retention. Because ALD employs gas-phase precursors and does not require any solvent, ALD can be also applied directly on a composite electrode, instead of on active material powders. Al2O3-coated NG electrodes by direct ALD on the composite electrode exhibit remarkable durable cycling capability (98% capacity retention after 200 charge-discharge cycles) even at 50oC. In sharp contrast ALD performed on NG powders prior to electrode fabrication yield inferior performance to that of bare NG. The degradation in performance is attributed to the insulating property of the Al2O3 film which inhibits electron conduction paths between NG particles and the current collector. When compared to a bare NG electrode, the fully lithiated, ALD coated NG electrode also exhibits significantly lower heat generation between 100-150oC, that may significantly improve LIB safety concerns. Prospects of ALD for application for other advanced electrode materials will be also discussed.
 Battery test manual for plug-in hybrid electric vehicle, http://www.inl.gov.
 C. Li, H. P. Zhang, L. J. Fu, H. Liu, Y. P. Wu, E. Rahm, R. Holze, H. Q. Wu, Electrochim. Acta 51, 3872 (2006).
 A. C. Dillon, A. W. Ott, J. D. Way, S. M. George, Surf. Sci. 322, 230 (2006).
 Y. S. Jung, A. S. Cavanagh, A. C. Dillon, M. D. Groner, S. M. George, S. Lee, J. Electrochem. Soc. in press.
12:15 PM - CC3.9
ALD and MLD Surface Coatings for Performance and Safety Enhancement.
Leah Riley 1 2 , A. Cavanagh 2 , S. George 2 , S. Lee 2 , A. Dillon 1 Show Abstract
1 , National Renewable Energy Laboratory, Golden, Colorado, United States, 2 , University of Colorado at Boulder, Boulder, Colorado, United States
Interfacial surfaces have commercial plagued battery development causing both reduced lifetime and safety concerns. Despite continuous improvements in capacity and stability for electrodes in both liquid and solid-state lithium batteries, ionic conductivity, dissolution, decomposition, and solid electrolyte interphase (SEI) formation often limit the ability for new materials to be commercially implemented. One commonly implemented method is to apply a thin surface coating.
Our studies focus on utilizing Atomic Layer Deposition (ALD) and Molecular Layer Deposition (MLD) to minimize harmful electrode/electrolyte interfacial effects. Unlike widely used wet-chemical techniques such as sol-gel, ALD and MLD are “dry” and self-limiting deposition processes. The precursors have been shown to traverse through porous material, providing a uniform and complete coating around particles and within electrodes. 
By coating our material, we plan to:
1)increase first cycle Coulombic efficiency
2) lengthen the cycle life of electrodes
3) help prevent harmful dendrite growth
4) safely increase maximum cell operating temperature
5)provide extra “cushion” around high capacity metals and metal oxides
6)widen possible voltage windows while maintaining performance
Previous studies showed the beneficial effects of ALD coatings on commercial graphite and LiCoO2 electrodes. For this study, we will report on improvements to high volume expansion nanomaterial anodes such as previously optimized MoO3  and Si, and select cathodic materials, such as Li(Co1/3Ni1/3Mn1/3)O2 and LiFePO4. Some examples of applied coatings include Al2O3, ZrO2, TiO2, Alucone, Lithium Carbonate, and phosphates.
 Y. S. Jung, A. S. Cavanagh, A. C. Dillon, M. D. Groner, S. M. George, S. Lee, J. Electrochem. Soc. in press.
 L. Riley, S.-H. Lee, L. Gedvilias, A. Dillon, Journal of Power Sources 2010, 195.
CC4: Cathode and Anode Materials
Wednesday PM, April 07, 2010
Room 3011 (Moscone West)
2:30 PM - **CC4.1
High Energy Density Metal Oxide Anodes for Solid-state Li-ion Batteries.
Anne Dillon 1 , Chunmei Ban 1 , Leah Riley 1 2 , Zhuangchun Wu 1 , Dane Gillaspie 1 , Le Chen 1 , Yanfa Yan 1 , Se-Hee Lee 2 Show Abstract
1 , National Renewable Energy Lab, Golden , Colorado, United States, 2 , University of Colorado at Boulder, Boulder, Colorado, United States
Significant advances in both energy density and rate capability for Li-ion electrode materials will be necessary for implementation of next generation solid-state batteries for various applications ranging from portable electronics to electric vehicles. By employing metal oxide nanostructures, it is possible to achieve Li-ion anodes that have significantly higher energy density than the state-of-the-art graphite technology. For example we have demonstrated that thin film MoO3 nanoparticle electrodes (~2 µm thick) have a stable reversible capacity of ~630 mAh/g when tested at C/2. By fabricating more conventional electrodes (~35 µm) with a conductive additive and binder, an improved reversible capacity of ~1000 mAh/g is achieved. The increased capacity for the MoO3 coin cell electrode compared to the thin film electrode may be attributed to improved electronic/ionic mobility with the conductive additive and more complete access to the nanostructures. More recently we have focused our work on iron oxide nanostructures, as iron is an inexpensive, abundant and a non-toxic material. Furthermore we have synthesized binder-free, high-rate capability thin electrodes (~3µm). The electrodes contain Fe3O4 nanorods as the active lithium storage material and carbon single-wall nanotubes (SWNTs) as the conductive additive. The highest reversible capacity is obtained using 5 wt.% SWNTs, reaching 1000 mAh/g (~2000 mAh/cm3) at C rate when coupled with a lithium metal electrode, and this high capacity is sustained over 100 cycles. Furthermore, the electrodes exhibit high-rate capability and stable capacities of 800 mAh/g at 5C and ~600 mAh/g at 10C. Scanning electron microscopy (SEM) indicates that this high-rate capability is achieved because Fe3O4 nanorods are uniformly suspended in a conductive matrix of SWNTs. Raman spectroscopy is employed to understand how the SWNTs function as a highly flexible conductive additive. We expect that our method can be used to achieve other binder-free anodes as well as cathodes with similar high-rate capability. S.-H. Lee et al., Adv. Mat. 20, 3627 (2008). L. A. Riley et al., J. Power Sources available on line (2009). N. A. Chernova et al., J. Mater. Chem. 19, 2526 (2009).
3:00 PM - CC4.2
Electrospun Silicon Nanowires as Lithium Anodes.
Douglas Schulz 1 , Justin Hoey 1 , Jeremiah Smith 1 , Xiangfa Wu 1 , Iskander Akhatov 1 , Larry Pederson 1 , Samy Elangovan 1 , Philip Boudjouk 1 , Jason Zhang 2 Show Abstract
1 Center for Nanoscale Science and Engineering, North Dakota State University, Fargo, North Dakota, United States, 2 , Pacific Northwest National Lab, Richland, Washington, United States
Silicon is an attractive anode material because of its exceptionally high theoretical capacity (4,200 mAh/g) and an electrochemical potential within a few hundred millivolts of metallic lithium. However, the high electrochemical capacity of Si is associated with very large (>300 %) lattice volume changes upon lithium ion intercalation, which can result in severe cracking/pulverization of the anode and therefore substantial capacity fade. Nanostructured Si in the form of thin films, nanoparticulates and especially nanowires hold promise for overcoming lattice expansion issues. However, such Si nanowires have not been available in quantities sufficient for practical performance evaluation. NDSU has developed unique synthetic routes to a novel liquid silicon precursor, cyclohexasilane (Si6H12). Readily purified by distillation, the liquid nature of Si6H12 allows the development of a high-volume electrospinning route for Si nanowire production. Because the spun wires convert to amorphous silicon at relatively low temperature, formation of excessive surface oxide and carbide phases can be avoided, which otherwise negatively affect capacity and rate capabilities. Electrochemical properties of the nanowires including capacity, fade, and rate capabilities were evaluated at PNNL.
3:15 PM - CC4.3
Hierarchically Structured Carbonaceous Foams Generation and Their Use as Electrochemical Capacitors and Negative Electrodes for Lithium-ion Batteries Devices.
Nicolas Brun 1 2 , Savari R.S. Prabaharan 3 4 , Mathieu Morcrette 3 , Raphael Janot 3 , Gilles Pecastaings 5 , Marc Birot 2 , Renal Backov 1 Show Abstract
1 , Centre de Recherche Paul Pascal - CNRS, Université de Bordeaux, Pessac France, 2 , Institut des Sciences Moléculaires - CNRS, Université de Bordeaux, Talence France, 3 , Laboratoire de Réactivité et Chimie des Solides - CNRS, Université de Picardie, Amiens France, 4 , Faculty of Engineering and Computer Science - The University of Nottingham, Semenyih Malaysia, 5 , Laboratoire de Chimie des Polymères Organiques - CNRS, Université de Bordeaux, ENSCPB, Pessac France
Mainly induced by the wide scope of applications expected, designing hierarchically organised matter appears today as a strong and competitive field of research. In this context, has emerged the concept of “integrative chemistry” , combining general chemistry with complex fluids, with a view to obtain engineered hierarchical structures. With this aim, our research group has recently developed a new process to obtain macrocellular silica monoliths, labelled “Si-HIPE”, with a high control on the final macroscopic cells, by using concentrated direct emulsion and lyotropic mesophase . Particularly, porous carbon materials are widely used in various areas as adsorbents for gas separation or wastewaters purification, electrodes for batteries or fuel cells, host sites for hydrogen storage and catalyst supports, mainly due to high surface area, chemical inertness and thermal stability. Over the last ten years, porous carbons with various pore sizes and pore structures have been synthesized using several different synthetic methods and templates , leading for instance to ordered mesoporous carbons [3b] or hierarchical interconnected carbon monoliths [3c]. In this direction, we designed hierarchically structured carbonaceous foams with a high control over macro-meso-microporous structures, using Si-HIPE as inorganic exotemplate and phenolic resin as carbon precursor . The potential applications of this new series of macrocellular carbonaceous monoliths as negative electrodes for Lithium-ion batteries devices, electrochemical capacitors  and host sites for hydrogen scavenging have been checked . The carbon precursor/inorganic template composites and the resulting carbon materials have been thoroughly characterized via a large set of techniques such as SEM, TEM, SAXS, XRD, Raman spectroscopy, mercury intrusion porosimetry, nitrogen adsorption, FTIR. Mechanical behavior in compression, electrochemical properties and control over hydrogen release will be discussed.References a) R. Backov Soft Matter, 2006, 2, 452; b) E. Prouzet, S Ravaine, C. Sanchez, R. Backov New J. Chem., 2008, 32, 1284. F. Carn, A. Colin, M.-F. Achard, H. Deleuze, M. Birot, R. Backov J.Mater.Chem., 2004, 14, 1370. a) J. Lee, J. Kim, T. Hyeon Adv.Mater., 2006, 18, 2073; b) R. Ryoo, S.H. Joo, M. Kruk, M. Jaroniec Adv.Mater., 2001, 13, 677; c) A. Taguchi, J.-H. Smätt, M. Linden Adv. Mater., 2003, 15, 1209; d) Z. Wang, A. Stein Chem. Mater., 2008, 20, 1029. N. Brun, C. Sanchez et R. Backov. International Patent, 2009, PCT/FR09/052085. N. Brun, S. R. S. Prabaharan, M. Morcrette, C. Sanchez, G. Pécastaings, A. Derré, A. Soum, H. Deleuze, M. Birot, R. Backov Adv. Funct. Mater., 2009, 19, 3136. N. Brun, R. Janot, C. Sanchez, R. Backov International Patent, 2009, PCT/FR09/052084.
3:30 PM - CC4.4
Application of 1D Magneli Phases TinO2n-1 as the Anode Material for Li-ion Batteries.
Weiqiang Han 1 , Xiaoliang Wang 1 , Yan Zhang 2 Show Abstract
1 Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York, United States, 2 Department of Physics and Astronomy, State University of New York, Stony Brook, New York, United States
Stoichiometric titanium dioxide (TiO2) is one of the most widely studied transition-metal oxides because of its many potential applications in photovoltaic solar cells, water-splitting catalysts for hydrogen generation. Titanium oxide has also been found to be a good candidate as a lithium ion host, since it has a high capacity material with low cost and no toxicity. There are three forms of stoichiometric TiO2 crystals: orthorhombic brookite, tetragonal anatase, and rutile. Electronically, these three TiO2 phases are wide-band-gap non-conducting materials, which limit the efficiency of solar conversion and energy storage. Magnéli phases TinO2n-1 are insoluble in acid, electrochemically stable, and have high electronic conductivity; accordingly, they are used in gas sensors, photoelectrolysis, and battery electrodes. Here, we describe a simple route to synthesize Magnéli phases TinO2n-1 nanowires. Subsequently, we evaluate their electric transport and optical properties. The electrical conductivity of the Ti8O15 and Ti4O7 samples at room temperature are 0.236 S/cm and 10.36 S/cm, respectively. Their absorption bands cover the full visible-light region and extend into the near IR region. We study their application as the anode material for Li-ion batteries. Detailed electrochemical and micro-structural results will be shown.
3:45 PM - CC4.5
Hydrothermal Carbon Nanocomposite Materials for Li ion Battery Anodes.
Magdalena Titirici 1 , Rezan Demir-Cakan 1 , Niki Baccile 1 , Robin White 1 , Jelena Popovic 1 , Yong Sheng Hu 1 , Markus Antonietti 1 Show Abstract
1 Colloids, Max-Planck Institute for Colloids and Interfaces, Potsdam Germany
The production of functional nanostructured materials starting from, cheap natural precursors using environmentally friendly proceses is one of the most attractive subjects in material science today. One route towards such materials is provided by a technique called hydrothermal carbonization1. The practical approach is very simple and consists in placing a biomass or biomass derivative inside an autoclave, in water, followed by hydrothermal treatment overnight at 160-200°C. Since the production of carbon materials in general implies harsher and multi-step methodologies, this process has clear advantages, being totally green, economical, mild and fast. Here, we wish to present our latest results on the production and characterization of nanostructured tin and silicon based carbon hybrids together with their performance when applied as negative electrodes in Li ion batteries. Both hybrids were prepared using hydrothermal carbonization of nitrogen containing carbohydrates (e.g. glucoseamine) in the presence of pre-formed Si or Sn nanoparticles. This leads to core/shell nanocomposites with a thin (1-3 nm) nitrogen doped carbon layer coated around the nanoparticles. Due to the presence of nitrogen within the carbon shell, the composites have a significant increased conductivity, showing high capacities up to ~ 1100 mAhg-1 for the Si/C system and ~ 960 mA h g-1 for the Sn/C respectively. Furthermore, the carbon layer formed around the nanoparticles buffers well against the volume change usually occurring in such nanoparticles upon Li insertion/desertion exhibiting excellent cycling performance and high rate capability, rendering them as promising candidates as an anode materials in lithium-ion batteries. 1 M.M. Titirici, M. Antonietti Chem. Soc. Rev., 2010, DOI: 10.1039/b819318p
4:00 PM - CC4: CAAM
4:30 PM - **CC4.6
Nanomaterials for Electrodes in Rechargeable Battery and Fuel Cell.
Byungwoo Park 1 , Yejun Park 1 , Yuhong Oh 1 , Jongmin Kim 1 , Changwoo Nahm 1 , Seunghoon Nam 1 Show Abstract
1 Department of Materials Science and Engineering, Seoul National University, Seoul Korea (the Republic of)
To overcome the limits of widely-utilized electrode materials in Li-ion batteries and fuel cells, various nanostructural attempts have been examined. The possibilities of producing more-efficient Li-ion-battery electrodes are offered by nanoscale/nanoparticle coating on the cathode or anode materials. Nanoscale control, such as nanomaterials, mesopores, thin films, and nanoscale coating, is applied to various materials for the enhanced stabilities.Despite significant progresses in proton-exchange-membrane fuel cells (PEMFCs) and direct-methanol fuel cells (DMFCs), prohibitive issues remain, such as the inefficient utilization of metal catalysts, the dissolution of catalysts, the low oxygen-reduction reaction (ORR), etc. The long-term stability and efficiency of catalytic nanoparticles may get enhanced by metal/phosphate nanocomposites, by a modification of electronic structure through the metal/phosphate interface. The involved mechanisms for the enhanced stability and efficiency will be discussed in this talk. Y. Park, B. Lee, C. Kim, Y. Oh, S. Nam, and B. Park, J. Mater. Res. (2009). C. Kim, B. Lee, Y. Park, B. Park, J. Lee, and H. Kim, Appl. Phys. Lett. 91, 113101 (2007). C. Kim, M. Noh, M. Choi, J. Cho, and B. Park, Chem. Mater. 17, 3297 (2005). J. Cho, Y.-W. Kim, B. Kim, J.-G. Lee, and B. Park, Angew. Chem. Int. Ed. 42, 1618 (2003).
5:00 PM - CC4.7
Unusual Kinetics and Nanosize Effects on the First Order Phase Transformation in LiFePO4.
Gerbrand Ceder 1 , Rahul Malik 1 Show Abstract
1 , MIT, Cambridge, Massachusetts, United States
LiFePO4 stores Li through a first order phase transformation between FePO4 and LiFePO4. Despite this two-phase reaction, which requires nucleation of the second phase and motion of a phase boundary through the material, this compound is probably the fastest intercalation compound known . We have used first principles computations to clarify the kinetic reaction mechanism of this material and now have developed an understanding and model for its high phase transformation kinetics. We believe that the theory we propose will have significant implications for finding other high rate materials that require a two-phase reaction for Li storage.We also find strong nanoeffects on the Li absorption kinetics. While normal diffusion control would lead to a square root dependence of diffusion time with particle size, the effects of particle size on lithiation/delithiation time in LiFePO4 are unlikely to follow this diffusion behavior and exhibit true nanoscale effects B. Kang, G. Ceder. Nature 458 (7235). pp. 190 - 193 (2009).
5:15 PM - CC4.8
ALD Surface Coatings for High Rate Performance of Nanoparticle LiCoO2.
Isaac Scott 1 , Andrew Cavanagh 2 , Steven George 3 4 , Se-Hee Lee 1 Show Abstract
1 Mechanical Engineering, University of Colorado, Boulder, Colorado, United States, 2 Physics, University of Colorado, Boulder, Colorado, United States, 3 Chemistry and Biochemistry, University of Colorado, Boulder, Colorado, United States, 4 Chemical and Biological Engineering, University of Colorado, Boulder, Colorado, United States
Efficient and durable electrical energy storage with high rate performance is one of the major limiting factors for Li-ion batteries. Performance at high charge and discharge rates is critically dependent on the size and morphology of the particles used to prepare the electrodes whereas capacity fade can be contributed to electrolyte decomposition, active material dissolution, phase transition inside the insertion electrode materials, and solid electrolyte interphase (SEI) formation. In addition, using nano over micron-sized particles dramatically decreases the length the Li+ must diffuse in the solid state and increases the high rate performance. Nanoparticle lithium cobalt oxide (LiCoO2) is synthesized using KNO3 as the high-temperature reaction media. This molten salt synthesis method has been reported to be one of the simplest means in preparing homogeneous LiCoO2 powder . The particle size is controlled by varying the flux (molar ratio of CoO:KNO3), the final heating temperature, and reaction dwell time. The synthesized nanoparticles act as the active material for “thick” composite cathodes, which are then coated with aluminum oxide (Al2O3) by atomic layer deposition. Charge-discharge experiments carried out at various c-rates along with electrochemical impedance spectroscopy (EIS) is used to evaluate the performance of the electrodes prepared using bare nanoparticle LiCoO2 and bulk LiCoO2 to that of Al2O3 ALD-coated nanoparticle LiCoO2 electrodes. These experiments show enhanced high-rate electrochemical properties in the Al2O3-coated LiCoO2 cathodes compared to both the uncoated and bulk. The improved rate behavior for the coated electrodes is caused by the suppression of cobalt dissolution from the LiCoO2 with the formation of an aluminum-oxide barrier residing between the LiCoO2 cathode and the liquid electrolyte and by decreasing the particles size from bulk material.1. H. Liang, X. Qiu, H. Chen, Z. He, W. Zhu, L. Chen, Electrochem. Commmun. 6 (2004) 789.2. Y. J. Kim, H. Kim, B. Kim, D. Ahn, J. –G. Lee, T. –J. Kim, D. Son, J. Cho, Y. –W. Kim, B. Park, Chem. Mater. 15 (2003), 15 (7) 1505.
5:30 PM - CC4.9
Single Crystalline Spinel LiMn2O4 Nanotubes as Cathode Materials for Li-ion Battery.
Yuanli Ding 1 , Jian Xie 2 , Gaoshao Cao 3 , Hongming Yu 4 , Xinbing Zhao 5 Show Abstract
1 Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, China, 2 Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, China, 3 Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, China, 4 Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, China, 5 Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, China
Spinel LiMn2O4 has been considered as one of the most promising candidates as cathode materials for Li-ion battery because of its low cost, nontoxicity and the high abundance of Mn resource. Compared with polycrystalline cathode materials, one-dimensional single crystalline nanomaterials are very attractive because of fast physical transport for Li Ions and electrochemical reactions with electrolyte. In the present work, we attempted to synthesize single crystalline LiMn2O4 nanotube in order to improve its electrochemical performance. It was found that single crystalline LiMn2O4 nanotubes could be easily synthesized by a simple soft chemical method. The as-prepared LiMn2O4 nanotubes showed a dimension of 400~500 nm in diameter, about 100 nm in tube thickness and 1~3 μm in length. Galvanostatic cycling test indicated that the LiMn2O4 nanotubes showed good rate capability and excellent cycling stability. A capacity retention rate of 80% was achieved for over 100 cycles at 1 C, and a discharge capacity of 80 mAh/g was still maintained after 200 cycles at the same rate. It was also interesting to note that, when the material was cycled at 2 C, over 90% of the initial discharge capacity can be retained after 100 cycles. The excellent electrochemical performance of the nanotubes can be attributed to the decreased Li-ion diffusion path, the increased effective surface contact with the electrolyte, and the enhanced ability to relax the strain caused by prolonged cycling. The excellent electrochemical performance of LiMn2O4 nanotubes makes it as promising cathode materials for high-rate lithium ion batteries.
CC5: Poster Session
Thursday AM, April 08, 2010
Salon Level (Marriott)
9:00 PM - CC5.1
Porous Silicon Anode for Rechargeable Lithium Batteries.
SriLakshmi Katar 1 , Azlin Biaggi Labiosa 2 , Venkata Puli 3 , Luis Fonseca 3 , Brad Weiner 1 , Gerardo Morell 3 Show Abstract
1 Chemistry, University of Puerto rico, SanJuan, Puerto Rico, United States, 2 Sensors and Electronics Branch, National Aeronatuics and Space Administration Glenn Research Center, Cleveland, Puerto Rico, United States, 3 Physics, Univ ersity of Puerto Rico, SanJuan, Puerto Rico, United States
Porous silicon (PS) negative electrodes with one-dimensional (1-D) channels have been successfully fabricated using an electrochemical etching process. The PS is characterized before and after the electrochemical lithium intercalation by Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X ray diffraction (XRD), Raman Spectroscopy. The electrochemical characterization was done by charge discharge studies and cyclic voltammetry. One-dimensional porous silicon appears to be a promising negative electrode for rechargeable micro-batteries.
9:00 PM - CC5.10
All-solid-state Thin Film Batteries With Sn-substituted LiMn2O4 Thin Film Cathodes.
Dong Wook Shin 1 2 , Ji-Won Choi 1 , Yong Soo Cho 2 , Seok-Jin Yoon 1 Show Abstract
1 , Korea Institute of Science and Technology, Seoul Korea (the Republic of), 2 , Yonsei University, Seoul Korea (the Republic of)
The development of thin film batteries, which provides high rechargeability, is important to meet the demands for small or integrated portable devices like active RF-ID (radio-frequency identification) tags, MAV (micro air vehicles), hybrid insect MEMS (microelectromechanical systems), etc. The cathodes of commercialized thin film batteries have been mostly LiCoO2 thin films. Whereas LiMn2O4 thin film cathodes have not been used for the application to thin film batteries although the LiMn2O4 has been one of the most viable materials alternative to the LiCoO2 due to its high operating voltage, low materials cost, and environmental benignity. In this study, the RF sputtered LiMn2O4 thin films, which exhibited higher rechargeability due to the prevention of oxygen deficiency and phase transition by Sn substitution [1,2], were applied to all-solid-state thin film batteries. The optimization of all-solid-state thin film battery, consisted of the cathode of Sn-substituted LiMn2O4 thin film, the solid electrolyte of Lipon (lithium phosphorous oxynitride) thin film, and the anode of lithium thin film, was performed in aspect of the interfacial reaction between the LiMn2O4 cathode and the Lipon electrolyte in order to improve the electrochemical performance such as capacity and capacity retention during a long-term cycle test.  D.W. Shin, J.-W. Choi, W.-K. Choi, Y.S. Cho and S.-J. Yoon, Appl. Phys. Lett., 93, 064101 (2008).  D.W. Shin, J.-W. Choi, W.-K. Choi, Y.S. Cho and S.-J. Yoon, Electrochem. Commun. 11, 695 (2009).
9:00 PM - CC5.11
Particle Size and Crystal Orientation Effects on the Electrochemical Behavior of Carbon-coated LiFePO4.
Eliana Quartarone 1 , Rodrigo Lassarote Lavall 1 , Stefania Ferrari 1 , Doretta Capsoni 1 , Piercarlo Mustarelli 1 , Aldo Magistris 1 , Patrizia Canton 2 Show Abstract
1 Dept of Physical Chemistry, University of Pavia, Pavia Italy, 2 Dept of Physical Chemistry, University of Venezia, Pavia Italy
In this work we investigate the influence of particle size and crystal orientation on the electrochemical behavior of carbon coated LiFePO4 as cathode for lithium batteries. The olivine was prepared by a hydrothermal synthesis in the presence of a polymeric surfactant and a source of carbon. We evaluate the charge/discharge profiles of two samples with different microstructures, one having a plate-like shape with large ac facet and (020) crystal orientation, and another one having a sub micron particles size with a random crystal orientation and more rounded particles. We show that at lower C rates the crystal orientation plays the main role in the electrochemical behavior of the cells, whereas at higher current rates smaller particles can allow a shorter electronic conduction path, which is important in reducing both the charge transfer resistance within the particles and the mass transfer resistance of Li ions.
9:00 PM - CC5.12
Preparation and Characterization of V2O5/LIPON/Li4Ti5O12 Thin Film Rechargeable Lithium Battery.
Eliana Quartarone 1 , Irene Quinzeni 1 , Stefania Ferrari 1 , Piercarlo Mustarelli 1 Show Abstract
1 Dept of Physical Chemistry, University of Pavia, Pavia Italy
The miniaturization of the electronic devices in terms of size and power requirements leaded up to the development of solid state thin-film batteries, based on lithium ion. Due to several advantages like the flexibility, safety, lightweight, high capacity and voltages, these systems find potential application as microsensors and actuators, medical devices or power sources in integrated measuring microsystem.Here we report on a the design and fabrication of a solid state lithium-ion microbattery, able to power sensors for the food traceability. Cells with the configuration V2O5/LIPON/Li4Ti5O12 were prepared by using sequential RF Magnetron sputtering technique. In order to optimize the battery assembly, the role of the deposition parameters in the films quality was addressed. Both electrolyte and electrodes layers were carefully investigated in terms of microstructure and electrochemical properties by means of AFM, XRD, MicroRAMAN, impedance spectroscopy, cyclic voltammetry and cycling tests.Particular attention was devoted to the preparation of Li4Ti5O12 film. Remarkable dependence of the film stoichiometry and phase purity was in fact observed as a function of sputtering parameters like substrate, oxygen pressure, temperature, target stoichiometry and annealing steps.
9:00 PM - CC5.14
Electrochemically Activated C-MEMS Structures as Microelectrodes for On-Chip Supercapacitors.
Majid Beidaghi 1 , Wei Chen 1 , Chunlei Wang 1 Show Abstract
1 Mechanical and Materials Engineering, Florida International University, Miami, Florida, United States
Supercapacitors as high power density devices can complement or even replace batteries in energy storage applications. Electrochemical double layer capacitors (EDLC’s) store charge through charge separation and ion adsorption on electrode materials. Application of porous carbon materials is one way to increase the effective surface area per volume of supercapacitor electrodes. However, effective surface area can also be increased by modifying the geometrical structure of the supercapacitor design. In this study, the Carbon-Microelectromechanical system (C-MEMS) technique is used to fabricate supercapacitors with high aspect ratio three dimensional (3D) carbon microelectrodes. The C-MEMS technique is a simple process for fabricating carbon electrodes, in which patterned photoresist is pyrolyzed and converted to carbon under high temperatures in an inert atmosphere. As-pyrolyzed carbon has crystalline structure comparable to commercial glassy carbon with inaccessible pores at subsurface. Although the capacitance of a 3D structure is higher than that of a planar structure at the same footprint, it is not comparable to capacitance of activated carbon electrodes. To activate C-MEMS electrode, anodic oxidation followed by a reduction step has been used. This method can open up the closed pores embedded in the carbon structure. Electrochemically activated C-MEMS samples have significantly higher specific capacitance compared to that of as-pyrolyzed samples. Using cyclic voltammetry (CV) and galvanostatic charge/discharge methods in an aqueous electrolyte, the effect of activation parameters and structural design on the performance of fabricated supercapacitors were investigated and will be reported at the conference.
9:00 PM - CC5.2
Composite Olivine Nanofibrous Cathodes for Lithium Ion Batteries.
Madhavi Srinivasan 1 , Yan Ling Cheah 1 , Subodh Mhaisalkar 1 Show Abstract
1 School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore, Singapore
Concurrent with progress in rechargeable lithium batteries (secondary lithium batteries), several lithium-conducting compounds have been intensively studied. Among them Lithium transition metal phosphates (olivines) have attracted immense interest as storage cathodes for rechargeable lithium batteries because of their high energy density (150-170mAhg-1), low raw materials cost, environmental friendliness and safety. During charge/discharge LiFePO4 electrodes are composed of LiFePO4 and FePO4, both poor electronic conductors. This extremely low electronic conductivity (10-9-10-10Scm-1) has been the key limitation of olivine phases. Attempts to enhance its electronic conductivity include carbon coatings (usually by means of pyrolysis of co-synthesized organic compounds), metal ion-doping and also particle size-reduction to the nanometer range. Among various nanostructured architectures, the nanofibre morphology has been previously mentioned to be more electrochemically strain-resistant as compared to nanospheres, nanopowders and thin films.In this study, we have adopted hydrothermal and electrospinning techniques for fabricating inorganic composite nanofibers of olivines. Electrospinning makes use of a high accelerating voltage to generate an electric field, which overcomes the surface tension of a polymeric solution and ejects a continuous jet, leading to the production of nanofibres on the collector surface upon evaporation of the solvent. The advantages of this process is the resulting nanofibre mats with large surface area and small pore sizes, which would facilitate lithium-ion transport by providing small electronic resistance and short diffusion pathway, and hence can deliver higher rate lithium-ion storage capability, faster charge-discharge kinetics, and better cyclic stability. As this technique also gives the possibility of co-spinning different materials simultaneously, LiFePO4-carbon composite nanowires can be obtained and the effects on the electrochemical and intercalation properties are studied. Preliminary testing has shown LiFePO4-carbon composite fibres to have a higher specific capacity (200-210 mAhg-1). Nanocomposites of olivines with carbon-based materials (carbon fibres / nanotubes) that possess large surface area [~1000-1600m2/g], excellent electrical conductivity [~103-104S/cm]) will be studied in an effort to further improve the electronic conductivity and prolong cycle life. Detailed fabrication procedures, characterization and electrochemical test results will be presented and discussed.
9:00 PM - CC5.3
Electrochemical Properties of TiO2 Nanotube/Graphite Composite Anode for Fast Charge/Discharge Characteristics of Lithium-ion Batteries.
Young-Gi Lee 1 , Min Gyu Choi 1 2 , Kwang Man Kim 1 Show Abstract
1 , Electronics and Telecommunications Research Institute(ETRI), Daejeon Korea (the Republic of), 2 , Graduate School of Chungnam National University, Daejeon Korea (the Republic of)
This study is focused on the nanostructured TiO2 anode active material, in particular, on the hydrothermal synthesis of TiO2 nanotubes and their composites with graphite in order to enhance the cycle performance and high-rate characteristics of lithium rechargeable battery. TiO2 powders (anatase, rutile, and their mixtures) as starting materials are hydrothermally reacted with 10 M NaOH aqueous solution in an autoclave at 150oC for 48 h. The product is then washed with 0.1 M HCl aqueous solution to obtain the layered hydrogen titanate. TiO2 nanotubes are finally produced by annealing the titanates at 300oC. TiO2 nanotube-graphite composite powders are also prepared by adding the graphites before and after the hydrothermal synthesis. Anode electrode is prepared by coating the slurry consisted with the sample powder, conductive agent, binder, and solvents. Lithium half-cells are fabricated by using the anode in a dry room (dew point<-40oC) to examine the charge/discharge characteristics. As emphasizable results, the composite anode prepared by adding the natural graphite before the hydrothermal synthesis shows the discharge capacity higher than 250 mAh/g when cycled 100 times at 0.2 C-rate. This sample also exhibits a superior high-rate capability that achieves ca. 70 mAh/g when cycled 100 times at 50 C-rate.
9:00 PM - CC5.4
High Performance Self-supported SnO2 Nanowires for Lithium Ion Battery Electrode.
Jin-Gu Kang 1 , Young-Dae Ko 1 , Dong-Wan Kim 2 , Young-Jin Choi 1 , Jae-Gwan Park 1 Show Abstract
1 Nano-materials Research Center, Korea Institute of Science and Techology, Seoul Korea (the Republic of), 2 Department of Materials Science and Engineering, Ajou University, Suwon Korea (the Republic of)
In the recent decade, rechargeable lithium ion battery (LIB) has been highlighted as the post-generation energy alternative in the diverse industrial fields including mobile electronic devices, electric automotive design, and ubiquitous networks. To suffice up-to-date technological trends such as light weight and compact design, LIB must demonstrate high energy density, high power density and long-term stability. Accordingly, the development of nanostructured electrode materials is of great significance due to their advantageous aspects such as larger electrode/electrolyte area, shorter electronic/ionic transport length, and better accommodation of the mechanical strain than their corresponding bulk state. Of various nanostructures, direct growth of low-dimensional nanomaterials on the current collector, called self-supported strategy, is highly preferred. This strategy provides efficient electronic pathway due to one-by-one contact of active material to current collector without any conductive additive, thereby minimizing contact resistance and electrical isolation phenomena. Herein, we report on the realization of self-supported SnO2 nanowires electrode with high theoretical capacity (~780 mAh/g) induced by alloying/dealloying lithium storage mechanism which differs from classical insertion/deinsertion reaction. The SnO2 nanowires were directly grown on the current collector (stainless steel substrate) without buffer layers by tip-led vapor-liquid-solid growth mechanism via thermal evaporation method. It was revealed that the diameter of nanowires ranged from 40 to 50 nm, and nanowires evolved along  preferential direction. Galvanostatic electrochemical measurements were performed to characterize the lithium storage properties of self-supported SnO2 nanowires electrode. It demonstrated stable cycling manner and high specific capacity of 510 mAh/g even at 50th cycle at a rate of 1C, which surpassed that of SnO2 nanopowder and Sn nanopowder electrodes. Furthermore, SnO2 nanowire electrode exhibited excellent rate capabilities, with rechargeable storage capacities of 600 mAh/g at 3C, 530 mAh/g at 5C, and 440 mAh/g at 10C. Our results hold a promise of fabricating novel nanostructured electrodes for high power lithium ion battery.
9:00 PM - CC5.5
One Step Sintering of Rechargeable Silver Solid State Batteries.
Gaelle Delaizir 1 , Negar Manafi 1 , Patrick Rozier 1 , Mickael Dolle 1 Show Abstract
1 , Centre d'Elaboration de Matériaux et d'Etudes Structurales, Toulouse Cedex 4 France
Solid state batteries are of great interest mostly because of safety (no leakage), miniaturization concerns and their resistance to a high increase of temperature without any damages. Limits of the solid state technology reside in the interface between the electrode and electrolyte where all the electrochemical reactions take place and also in the good choices of the different components of the system that have to be chemically and electrochemically compatible. In the solid state technology, the cycling (charge-discharge) of the battery implies some volume changes inside the electrode (insertion-extraction of ionic species), therefore the interfaces are the critical part of the solid state system since they are the place of mechanical strength. The system of electrodes and electrolyte Ag0.7V2O5//Ag6I4WO4//Ag0.7V2O5 is already known and had been previously assembled by cold pressing. In this study, the same system is assembled by Spark Plasma Sintering (SPS). The symmetric system of electrodes is preferred for SPS technique since the current pulses that cross the stacking imply the system to be in the discharged state after sintering. AgxV2O5 exhibits a δ phase for 0.66
9:00 PM - CC5.6
Solid-state Batteries That Should Work, But Don’t.
Nancy Dudney 1 , Yoon Kim 1 , Can Erdonmez 2 , Chang-Jun Bae 2 , Yan Wang 2 , Yet-Ming Chiang 2 Show Abstract
1 Material Science and Technlogy Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States, 2 Department of Material Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
Several attempts to make self-supporting solid-state lithium batteries with the thin film Lipon electrolyte have failed. These attempts have utilized dense LiCoO2 and LiMn2O4 cathodes formed by sintering of either tape cast or cold pressed pieces. From transport results of thin film cathodes, cathode thicknesses of 30-100µm should be accessible for charging and discharging at moderate rates, yet solid-state batteries with sintered cathodes cycle poorly. For our studies the solid electrolyte is a sputtered-deposited film of glassy lithium phosphorous oxynitride (Lipon) with a thickness sufficient to cover the irregularities of the sintered surface. The anode is evaporated or electrodeposited lithium. Experiments and simulations will be discussed that seek to reveal why all-solid-state batteries fabricated with dense sintered cathodes cycle poorly, compared to the thin film batteries with vapor deposited cathodes.Acknowledgements: This work was supported by DARPA Defense Sciences Office and also by the U.S. Department of Energy, Assistant Secretary for Energy Efficiency and Renewable Energy, Office of FreedomCAR and Vehicle Technologies.
9:00 PM - CC5.7
LaF3-BaF2-KF Derived Electrolyte in Solid State Fluoride-ion Battery.
D. Wang 1 , M. Anji Reddy 1 , H. Hahn 1 , M. Fichtner 1 Show Abstract
1 , Karlsruhe Institute of Nanotechnology, Eggenstein-Leopoldshafen Germany
Solid-state fluoride-based battery technology offers the largest temperature range (from room temperature to 500 ºC) of any battery technology. The chemical reaction used to create electrical energy occurs as a solid-state reaction .Among the many types of solid preparation techniques, the nonconventional mechanochemical synthesis has been recognized as a powerful route to novel, highperformance, and low-cost materials . Formation of a mixed and highly disordered fluoride phase with retained cubic symmetry might be responsible for the unexpected high F¯ diffusivity .LiF is a poor electronic and ionic conductor at room temperature. It is important to find out whether the very stable LiF can be reversibly decomposed by other metal fluorides due to different electrochemical potentials .In our group, we developed a series of new electrolytes, namely the LaF3-BaF2-KF solid solutions, using mechanosynthesis method. The cubic structure of the product was confirmed by XRD. The nanoscale nature and morphology of the samples were characterized by SEM and TEM. 19F NMR spectroscopy was used to characterize the mobility of F¯ ions.Solid-state electrochemical cells were constructed with LiF based composite cathode, LaF3-BaF2-KF derived electrolyte and Fe based composite anode. 57Fe Mössbauer spectroscopy measurements revealed the material transformation at the anode side.1. Sandia National Laboratories, Solid-state battery, R&D 100 (2006)2. V. Sepelak, Chem. Mater. 18, 3057-3067 (2006)3. B. Ruprecht and P. Heitjans, J. Mater. Chem., 18, 5412-5416 (2008)4. H. Li and J. Maier, Adv. Mater., 15, 736-739 (2003)
9:00 PM - CC5.8
Effect of Nanotube Geometry on Li Storage Kinetics in Oriented TiO2 Nanotube Arrays.
Jae-Hun Kim 1 , Kai Zhu 1 , Arthur Frank 1 Show Abstract
1 Chemical and Materials Science Center, National Renewable Energy Laboratory, Golden, Colorado, United States
Rechargeable lithium-ion batteries have become one of the most popular portable energy sources for consumer electronics because of their high energy density and lack of memory effect along a decline in price. Among various electrode materials for Li batteries, TiO2 has attracted [1-3] attention because of its high rate capability and enhanced safety, which are essential properties of rechargeable Li-ion batteries for hybrid electric vehicle applications. The architecture of most TiO2 electrodes consists of disordered particle or nanowire films. In this presentation, we report the syntheses and electrochemical properties of vertically alingned TiO2 nanotube (NT) arrays as electrodes for Li-ion batteries. The linear arrangement of pores are expected to facilitate fast electronic/ionic conduction and to accommodate large volume changes of the electrode materials during charge/discharge cycling.[4,5] The NT arrays were fabricated by electrochemical anodization of Ti foil. X-ray diffraction analysis indicates that annealing the as-grown films at a temperature of 400 oC transforms them from an amorphous phase to anatase TiO2. The NT film morphology (e.g., pore diameter and wall thickness) and pore alignment are found to affect significantly the Li insertion-extraction kinetics (e.g., electrons/ions conduction and interfacial charge transfer) and the performance of the electrodes in rechargeable Li batteries. These results and others are discussed.  L. Kavan et al., J. Phys. Chem. B 104, 2897 (2000).  Y. S. Hu et al., Adv. Mater. 18, 1421 (2006).  A. R. Armstrong et al., Adv. Mater. 17, 862 (2005).  Z. Kai et al., Nano Lett. 7, 69 (2007).  Z. Kai et al., Nano Lett. 7, 3739 (2007).
Se-Hee Lee University of Colorado-Boulder
Akitoshi Hayashi Osaka Prefecture University
Nancy Dudney Oak Ridge National Laboratory
Kazunori Takada National Institute for Materials Science
CC6: Li-ion Battery Materials
Yoon Seok Jung
Thursday AM, April 08, 2010
Room 3011 (Moscone West)
9:30 AM - **CC6.1
Detecting Li-Ion Currents on the Nanoscale.
Nina Balke 1 , Stephen Jesse 1 , Yoongu Kim 1 , Leslie Adamczyk 1 , Nancy Dudney 1 , Sergei Kalinin 1 Show Abstract
1 CNMS, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States
The development of the capability for probing ion transport on the nanometer scale is a key challenge for development of energy storage and generation systems including Li-ion batteries, and can potentially unravel complex interplay between structure, functionality, and performance in these systems. However, the existing electrochemical methods invariably utilize slow and large scale ion electrodes, limiting these studies to ~10 micron scale, well above the characteristic size of grains and sub-granular defects. Consequently, the nanoscale mechanisms underpinning Li-ion battery functionality remain unexplored, precluding developing strategies for improvement of energy and power densities and life times of these devices. Here we demonstrate the Scanning Probe Microscopy approach for mapping ionic current in Li-ion batteries. The high frequency periodic bias is applied between the cathode and anode of Li-ion battery, and the Scanning Probe Microscopy tip acts as a probe of local periodic strains generated due to Li-ion redistribution and associated changes in molar volume of material. A slower voltage sweep is used to induce Li ion redistribution on the length scale of the probe, providing optimal conditions for high-resolution imaging. Using the band excitation method, the quantitative cross-talk free imaging is demonstrated. The lithium diffusivity is mapped on a level of a single grain-boundary like defect in Si-anode material. The evolution of Li activity during fade-out process is observed and correlated with macroscopic measurements. Finally, the bias-dependence of response is used to explore the critical bias required for the onset of electrochemical transformation, potentially allowing to deconvolute reaction and diffusion processes. This material is based upon work supported as part of the Fluid Interface Reactions, Structures and Transport (FIRST) Center, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number ERKCC61 (Y.K., S.J., L.A., N.D., S.V.K.). N.B. acknowledges the Alexander von Humboldt foundation for financial support.
10:00 AM - CC6.2
Structure - Property Relationship in Electrode Materials for Li-ion Battery Applications.
Nader Marandian Hagh 1 , MuMu Moorthi 1 , Ganesh Skandan 1 , William West 2 , Ratnakumar Bugga 2 , Shirley Meng 3 Show Abstract
1 , NEI Corporation, Somerset, New Jersey, United States, 2 , Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, United States, 3 , University of California at San Diego, San Diego, California, United States
The layered structure material with nominal composition of Li1+xMO2 (M: Ni, Co, Mn) has been studied due to the exceptionally high discharge capacity (≥270 mAh/g) and high energy density. Despite these attractive features the stability and consistent long term cycle life of the material has been remained a challenge toward the material’s commercialization. Due to the fact that materials at nanoscale represent the improved performance with respect to power density but not necessarily to cycling stability, the combined effects of microstructural characteristics (primary particle size, morphology), surface chemistry, compositional homogeneity, and metal-ion order/disorder with respect to electrochemical performance of the material will be discussed.The results will also be compared with different electrode chemistries such as lithium titanate spinel (Li4Ti5O12) anode, nickel cobalt aluminum layered oxide (LiNi1-x-yCoxAlyO2) and doped spinel (LiMn1.5-xNi0.5MxO4; M: transition metal) cathodes to explore the broader spectrum of property-processing relationship among the different electrode materials.
10:15 AM - CC6.3
Structure and Ion Transport Pathways in 0.45Li2O-(0.55-x)P2O5-xB2O3 Glasses.
Thieu Tho 1 , Rayavarapu Prasada Rao 1 , Stefan Adams 1 Show Abstract
1 Materials Science and Engineering, National University of Singapore, Singapore, Singapore, Singapore
Alkali borophosphate glasses are of technical interest as fast ion conductors with high chemical durability but also of theoretical interest as model substances for studies of the mixed glass former effect. Here, lithium borophosphate glasses, 0.45Li2O-(0.55-x)P2O5-xB2O3 (0≤x≤0.4) were prepared using melt quenching method. XRD confirms the glass forming region within a range of 0≤x≤0.4. In our studies, the molar ratio of Li2O/(P2O5+B2O3) was kept constant to focus on the influence of cation mobility changes due to the mixed glass former effect. As the B2O3 content increases, the glass transition temperature (Tg) increases, while the glass density passes through a maximum at x=0.2. To understand the correlation between structure and property, samples are characterized by Raman and XPS spectroscopy. Raman spectra reveal that the glass matrix undergoes structural modification for x≥0.15 leading to the formation of BPO4, (P2O7)4- and (B-O-P)- units. XPS studies showed that, when the B2O3 content is increased to x≥0.15, besides P-O-P and P-O- bonds, a third intermediate O1s peak emerges that can be assigned to P-O-B bonds. This peak rises in intensity with increasing B2O3 content when compared to P-O-P and P-O- bonds.The electrical conductivity of this glassy system has been determined over the temperature range 360K to 479K and the frequency range (f) from 1Hz to 15MHz by means of impedance spectroscopy. The highest ionic conductivity of 3x10-6 S.cm-1 (at T=360K) with a low activation energy of 0.632eV was observed for x=0.3. Analysis of the frequency dependence of ionic conductivity at various temperatures of the electrolytes helps to reveal insight into the hopping frequency of ions, their temperature dependence, and extrapolated dc conductivity. Three distinct regions in the conductivity spectra are observed for 0.45Li2O-(0.55-x)P2O5-xB2O3 glasses above room temperatures: (i) the high frequency dispersive region (f >104 Hz), (ii) the central plateau region or dc regime and (iii) the low frequency dispersive region. A single master curve for ac conductivity scaling is obtained at all temperatures, indicating that the relaxation mechanism is temperature independent.To complement the experimental studies, atomistic Molecular Dynamics (MD) simulations are used to explore the intermediate range ordering of the network formers, P2O5 and B2O3, and their influence on the glass structure. The resulting structure models are consistent with the spectroscopic results. Based on such realistic models of the local borophosphate glass structures for a range of B2O3 / P2O5 ratios, structural effects on ion transport as the origin of the mixed glass former effect can be quantified by applying the bond valence analysis approach to equilibrated MD trajectories.
10:30 AM - CC6.4
Vitreous Materials as Electrodes for Lithium Batteries.
Gaelle Delaizir 1 , Vincent Seznec 2 , Patrick Rozier 1 , Christine Surcin 2 , Philippe Salles 1 , Mickael Dolle 1 Show Abstract
1 , Centre d'Elaboration de Matériaux et d'Etudes Structurales, Toulouse Cedex 4 France, 2 , Laboratoire de Réactivité et Chimie des Solides, Amiens France
Until now, the materials investigated to find new suitable intercalation host structures for applications in Li or Li-ion batteries have been essentially crystalline materials. While glasses as potential electrode material or solid electrolyte for all solid state batteries have been studied in the 80’s, the research on such compounds for electrochemical applications has since been slowing down even though they are promising materials. We believe that this is due to the difficulty to characterize amorphous system at that time. Now, different techniques such as WAXS (Wide Angle X-Ray Scattering) and Raman allow us to have a better understanding of their structure. Electronic and ionic conductivity is studied in many ternary glasses such as Li2O-B2O3-V2O5. The potentiality of glasses as cathode materials has already been studied in the V2O5-P2O5 system which exhibit high capacity and a good reversibility or in the TeO2-V2O5 system.In our study, glasses in the Li2O-P2O5-V2O5 ternary system have been investigated as potential positive electrode materials for rechargeable lithium batteries. This ternary system exhibits a large vitreous domain leading to a wide choice of glassy compositions. In contrary to crystalline materials, the composition of vitreous materials, obtained by the conventional quenching method, can be easily modified. A good understanding of the relationship structure-properties for the glasses should then enable to adjust their composition to optimize the desired properties. A special composition 25Li2O-50V2O5-25P2O5 that exhibits a mixed ionic/electronic conductivity has been isolated and then characterized in terms of electrochemical properties. Ionic conduction in these glasses occurs via transport of Li+ ions while electronic transport consists in the electron hopping between V4+ and V5+ centers. It is assumed that lithium vanadate-phosphate glasses with high vanadium content exhibit predominantly electronic conduction while those having low vanadium content are predominantly ionic conductor. In glasses of intermediate composition, we observe mixed electronic-ionic conductivity. The special composition 25Li2O-50V2O5-25P2O5 has been characterized by WAXS, Raman, DSC and electrochemical behavior has been studied.
10:45 AM - CC6.5
Amorphous and Anatase TiO2 Nanotube Arrays for Enhanced Li-ion Intercalation Properties.
Ying Wang 1 , Dongsheng Guan 1 , Chuan Cai 1 Show Abstract
1 Mechanical Engineering, Louisiana State University, Baton Rouge, Louisiana, United States
We have employed a simple and novel process of anodizing titanium foils to prepare self-organized amorphous TiO2 nanotube arrays which demonstrate enhanced electrochemical properties for applications as lithium-ion battery electrode materials. The lengths, outer and inner diameters of nanotubes can be finely tuned by varying voltage, anodization time or electrolyte compositions; for example, the nanotube lengths can be controlled from a few microns to tens of microns long. The as-prepared nanotubes are very well-aligned and directly perpendicular to the titanium substrate. Heat treatment at 480oC converts amorphous TiO2 nanotubes into anatase nanotubes with identical morphological features. The discharge/charge properties and cycling performance have been investigated for amorphous and anatase TiO2 nanotube arrays, respectively. The capacity of amorphous nanotubes is larger than that of anatase nanotubes. For nanotubes with a length of 3 μm, an outer diameter of 150 nm and an inner diameter of 85 nm, the amorphous nanotube array delivers a capacity of 89.5 μA h cm-2 at a current density of 457 μA cm-2. For nanotubes 10 µm long, the amorphous nanotube array delivers a capacity of 896.6 μA h cm-2 at a current density of 560 μA cm-2. Both demonstrate much better Li-ion intercalation properties particularly at high discharge rates than the TiO2 nanotube arrays reported in literature most recently. Both amorphous and anatase nanotube arrays show a good capacity retention of 90% over 50 cycles. SEM images of cycled nanotubes show little change in morphology compared to nanotubes before cycling, indicating the excellent structural stability of these TiO2 nanotube arrays during cycling, which suggests that these TiO2 nanotube arrays are promising electrode materials for lithium-ion rechargeable batteries.
11:00 AM - CC6: LIBM
11:30 AM - **CC6.6
Real Time in situ Spectro-Electrochemistry of a Full Li-ion Cell in an Edge Configuration.
Jagjit Nanda 1 , Jeffrey Remillard 2 , Rajeswari Chandrasekaran 3 , Ted Miller 2 , Dawn Bernardi 2 Show Abstract
1 Materials Science and Technology, Oak Ridge National Lab, Oak Ridge, Tennessee, United States, 2 Research and Advanced Eng., Ford Motor Co., Dearborn, Michigan, United States, 3 Chemical and Bio-Molecular Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States
Understanding the solid and liquid phase lithium transport in a working Li-ion cell is critical to harness their full capacity utilization. Using a specially designed Micro-Raman Li-ion cell we have monitored the state of charge (SOC) variation across the spatial thickness of the electrodes. The full Li-ion cells consisted of LiNi0.8Co0.15Al0.05O2 (NCA) as the positive electrode and graphitic carbon as the negative electrode.1 Spatially resolved (~1μm) Raman spectra were obtained for the cell under both galvanostatic and potentiostatic conditions. Using a SOC parameter of individual active particles from Raman spectrum as reported by Kostecki et al.2-3 we monitored Li-transport and their associated inhomogenity across the full width of the electrode. Concomitant measurements were also performed at the graphite counter electrode to study the degree of lithium intercalation as obtained from their Raman signature. Comparisons were made between particles spatially located at the current collectors versus those near the separators. Our results will provide experimental validation to Li-ion electrode transport modeling and highlight the importance of addressing the issue of transport across the solid-liquid interfaces. 1. In-situ Spectro-electrochemistry on Individual Electrode Particles in a Lithium-ion Full Cell in Edge Configuration, Jagjit Nanda et al. (Manuscript in preparation)2. R. Kostecki and F. McLaren, Electrochem. and Solid-State Lett. 7, pgs. A380-A383 (2004).3. R. Kostecki, J. Lei, F. McLarnon, J. Shim, and K. Striebel, J. Electrochem. Soc. 153, pgs. A669-A672 (2006).
12:00 PM - CC6.7
Using the Direct Electrodeposition of Cu2Sb Coupled With Transmission Electron Microscopy to Probe the Mechanism of Lithiation of this Anode Material.
James Mosby 1 , Derek Johnson 1 , Amy Prieto 1 Show Abstract
1 Chemistry, Colorado State University, Fort Collins, Colorado, United States
We have developed the direct electrodeposition of Cu2Sb, an interesting anode material for Li-ion rechargeable batteries, from water at room temperature. Cu2Sb was electrodeposited as nanowires (via deposition into porous alumina templates) and onto transmission electron microscopy grids, in order to investigate changes in morphology, composition, and crystal structure during the early stages of nucleation and growth and after lithiation. Multiple transitions were observed within the first second of the deposition leading to the formation of the crystalline compound. Upon lithiation, clear evidence for the extrusion of Cu and the formation of Li2CuSb and Li3Sb were observed. These transitions were analyzed using transmission and scanning electron microscopies (TEM and SEM), selected area electron diffraction (SAED), and energy dispersive spectroscopy (EDS). This investigation is unique because TEM grids allow the interface between the deposited material and the substrate to be investigated, and allows for excellent contact so the same sample can be analyzed after lithiation. This approach can be extended to other systems, allowing the development of a comprehensive understanding of the electrodeposition of other intermetallic compounds and of the mechanism of lithiation for Cu2Sb.
12:15 PM - CC6.8
Synthesis and Crystal Structure of Langbeinite Hydrates: LiM2(PO4)3.2H2O (M = Zr, Hf).
Shuang Chen 1 2 , Stefan Hoffmann 1 , Yurii Prots 1 , Jing-Tai Zhao 2 , Ruediger Kniep 1 Show Abstract
1 , Max Planck Institute for Chemical Physics of Solids, Dresden Germany, 2 , Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai China
Lithium MIV phosphate dihydrates LiM2(PO4)3.2H2O (M = Zr, Hf) were synthesized under mild hydrothermal condition. The crystal structure of LiZr2(PO4)3.2H2O was determined from single-crystal X-ray diffraction data: cubic, space group P213 (No.198), a = 10.2417(1) Å, V = 1074.28(2) Å3, Z = 4. LiZr2(PO4)3.2H2O owns the framework of langbeinite, which consists of corner sharing [ZrO6] octahedra and [PO4] tetrahedra with Li ions and crystal water occupying the large cages along the 4 three-fold axes. The homologous compound LiHf2(PO4)3.2H2O was obtained as powder. Using the above-described crystal structure model of LiZr2(PO4)3.2H2O as a starting point and replacing Zr by Hf, the pattern was succefully fitted. The lattice parameter was found to be a = 10.1934 Å, which is slightly smaller than the one for LiZr2(PO4)3.2H2O, this is because in an octahedral environment the ionic radius of Hf4+ (r = 0.71 Å) is smaller than the ionic radius of Zr4+ (r = 0.72 Å). Thermochemical properties of LiZr2(PO4)3.2H2O were studied through TG-DTA followed by isothermal annealing experiments.