By : Knowledge Foundation
Date : 2011
Location : United States US / Las Vegas
Focused on the recent innovations within lithium-ion batteries that have propelled the technology into a position in the marketplace far exceeding recent market survey results.
Vehicle to Grid, V2G, CEA-LITEN, Lithium-ion Batteries, Li/air batteries, manganese dioxide electrode, lithium intercalated manganese dioxide, Battery Management System, LIB Performance, Calorimetry Technology
This combined on demand webcast and conference documentation download package will address the widely publicized safety incidents and recalls of lithium-ion batteries have raised legitimate concerns regarding lithium-ion battery safety. In addition, recent significant innovations within lithium-ion batteries have propelled the technology into a position in the marketplace far exceeding recent market survey results. Breakthroughs in new battery chemistries, novel electrode and electrolyte materials, system integration for a vast array of mobile and portable applications, from micro medical devices to high-energy/high-power automotive, have paved the roadmap for an emerging market with unlimited potential.
Battery Safety & Lithium Battery Power address these concerns by exploring the following topics :
• Major battery degradation and reliability factors
• Battery management systems
• Commercial cells evaluation and failure analysis
• Advances in testing techniques and protocols
• High throughput testing, automation and modeling for better safety
• Standardization and regulatory issues
• Meeting the EV challenge: cycle life, power & energy, cost and safety
• New chemistries & materials to increase energy & decrease cost
• Advanced materials for improved electrode & electrolyte performance
• Application driven lithium ion battery developmentAdvanced technology for greater safety, reliability and performance
• From novel materials and components to systems design and integration
• Role of nanotechnology in improving power and energy density
TABLE OF CONTENTS
Rechargeable Batteries for the 300-Mile Electric Vehicles and Beyond
K.M. Abraham, PhD, Chief Technology Officer, E-KEM Sciences
Today’s lithium ion batteries are unable to satisfy the energy density and cost requirements of 300-mile all-electric vehicles. New rechargeable batteries have to be identified and developed in order to meet this challenge. A brief update of lithium ion technology will be provided with its energy density and cost evolution in the foreseeable future. New materials and battery systems for meeting the driving range of extended range all-electric vehicles will be discussed along with updates on the rechargeable Li-air and Li-sulfur batteries.
Recent Advances in Rechargeable Battery Technology: An Overview
Ralph J. Brodd, PhD, Director, Kentucky - Argonne Battery Manufacturing Research and Development Center
Recent work on new electrode materials and structures will be reviewed along with comments and the implication for their ability to meet demands for the high performance, cycle life as well as cost for electric vehicle applications. The increased interest in electric vehicle batteries has stimulated significant new work on cell components, including anodes, electrolytes and separators. A potential issue is available resources relating to the supply critical elements for large scale vehicle cell production. While the availability of lithium resources is assured, other elements such as nickel and cobalt will require consideration and recycling as the market expands. Exciting new systems such as lithium alloy anode materials and lithium - air cells are beginning to challenge Li-ion system for utility in vehicle applications.
Subsonic Ultra Green Aircraft Research (SUGAR) Study Results: Hybrid Electric Propulsion with Advanced Battery Technology
Marty Bradley, PhD, Technical Fellow, Principal Investigator, Subsonic Ultra Green Aircraft Research The Boeing Company*
This presentation summarizes the work accomplished by the Boeing Subsonic Ultra Green Aircraft Research (SUGAR) team in a NASA study looking at future concepts and technologies for commercial aircraft in the 2030-2035 timeframe. The team developed a comprehensive future scenario for world-wide commercial aviation, selected baseline and advanced configurations for detailed study, generated technology suites for each configuration, conducted detailed performance analysis, calculated noise and emissions, assessed technology risks and payoffs, and developed technology roadmaps for key technologies. A wide portfolio of technologies was identified and evaluated to address the NASA goals. The highest payoff technologies were identified as hybrid-electric gas turbine propulsion and advanced modular batteries. Compared to today’s aircraft, fuel burn reductions of up to 90% and energy use reductions of greater than 55% are possible. To achieve this, significant advances in battery technology are needed and aviation specific challenges need to be addressed. The goal of this presentation is to begin a dialog between the aviation industry and battery technology and system experts to eventually enable the benefits identified in this study to come to fruition.
*In collaboration with: D.Coates, Boeing; R.Delrosario, NASA Glenn Research Center; R.Wahls, NASA Langley Research Center
Zero-Volt Technology with High Power Characteristics
Hisashi Tsukamoto, PhD, CEO, CTO and Co-Founder, Quallion LLC
Quallion has developed Zero-Volt™ technology (US Patent 6,596,439) for medical implantable Li-ion battery. This technology allows Li-ion battery deep discharged to “zero volt” and stored prolonged time, and be able to recharge without any damage. Quallion recently advanced this technology for high power Li-ion battery for military applications. We believe this technology can benefit calendar life and safety for various commercial applications including EV.
How Long Will Automotive Li-Ion Last In Real-World Applications?
Kandler Smith, Senior Researcher, National Renewable Energy Laboratory*
Laboratories run around-the-clock aging tests to try to as quickly as possible gain an understanding of how long new Li-ion battery designs will last under certain duty-cycles. Such tests, however, are generally accelerated and do not consider possible dwell time at high temperatures and states-of-charge. Furthermore, automotive duty-cycles are highly variable, making it difficult to span the realm of real-world duty-cycles in the laboratory. To overcome these issues, battery life-predictive models provide guidance as to how long Li-ion batteries may last under real-world electric-drive vehicle applications. Worst-case aging scenarios are extracted from hundreds of real-world duty-cycles developed from vehicle travel surveys.
*In collaboration with: M.Earleywine, S.Santhanagopalan, A.Pesaran
How to Have Your Cake & Eat It Too - An Investigation into Innovation-Driven High Performance, Cost-Effective Battery Systems
Gitanjali DasGupta, Manager, Electric Vehicle Division, Electrovaya, Canada
Large battery systems for automotive and utility applications is a rapidly developing market segment. The most pressing challenges for large-format applications are generally agreed to be lower battery cost and improved performance. In this paper, Electrovaya investigates the three pillars of the cost structure to demonstrate how advanced technology and clean manufacturing processes can drive both reduced cost and exceptional performance.
Translating High Capacity Materials into High Energy Density, High Performance Cells
Brian M. Barnett, PhD, Vice President, TIAX LLC
For several years, TIAX has been developing a stabilized nickelate cathode material that provides a unique combination of both high capacity and high power, and is an excellent option for portable, transportation and specialty applications. This material has now been implemented in cells by multiple manufacturers of lithium-ion cells, a process that necessarily involved development of detailed cell designs as part of the implementation. Most materials developers are not able to make cells, and yet cell-level performance is the ultimate requirement and cell-level performance sets the most pertinent materials targets. We have found that a combination of cell design models and relevant experimental data can help bridge the gap to cell level performance and also set appropriate development targets. This presentation illustrates the challenge of identifying relevant active materials targets to deliver enhanced performance at the cell level. In addition to the impact of TIAX new stabilized nickelate-based cathode material at the cell level, the presentation puts in a cell-level context some of the other recent high capacity materials developments for lithium-ion anodes and cathodes.
An Update on the Materials Development at JPL for Enhancing the Specific Energy and Safety of Li-Ion Cells
Ratnakumar V. Bugga, PhD, Principal Member Technical Staff, Electrochemical Technologies Group, Jet Propulsion Laboratory, California Institute of Technology*
For enhancing the future NASA missions that will involve robotic as well as human exploration, we will need rechargeable batteries with improved specific energy and safety. Under a NASA-sponsored program and in collaboration with other centers and external partners, we have been developing new cathode materials with higher voltage and enhanced specific energy, as well as electrolyte formulations with high voltage compatibility and reduced flammability. In this paper, we will present the performance characteristics as well as basic electrochemical studies of the materials in laboratory cells.
*In collaboration with: W.West, M.C.Smart
NCM Cathode Materials with High Energy Density for the Emerging Automotive Market
Kirill Bramnik, PhD, Global Product Technology Manager, Battery Materials, BASF Corporation
NCM (Nickel-Cobalt-Manganese based oxides) cathode materials for Li-ion batteries employ a unique combination of Lithium and Manganese rich mixed metal oxides and have successfully substituted LCO in many consumer applications. It is also the material of choice for large auto-batteries due to lower costs, intrinsically higher safety and extended cycling stability. Moreover, the enhanced stability of the NCM chemistry enables development of new battery systems, which can be charged to the higher voltages and leads to a substantially higher energy storage capacity than currently available materials. The increased capacity of such materials goes hand in hand with reduced costs and therefore offers a number of advantages for battery makers. Dedicated design of particles together with high purity makes BASF materials well suited for demanding applications such as batteries for automotive drivetrains.
Discovery of 5V Cathode and Electrolyte Materials via High Throughput Methods
Steven Kaye, PhD, Chief Scientific Officer, Wildcat Discovery Technologies
Wildcat Discovery Technologies has developed a high throughput synthesis and screening platform for battery materials. Wildcat’s system produces materials in bulk form, enabling evaluation of its properties in a standard cell configuration. This allows simultaneous optimization of all aspects of the cell, including the active materials, binders, separator, electrolyte and additives. Wildcat is using this high throughput system to develop new electrode and electrolyte materials for a variety of battery types (primary, secondary, aqueous, non-aqueous). In this talk, I will discuss results from our latest discovery programs, including new 5V cathodes and electrolytes with >700 Wh/kg and significantly improved cycle life in full cells.
Transition Metal Oxynitride as Electrode Material for Rechargeable Li-Ion Battery
Xiao-Jun Wang, PhD, and Reinhard Nesper, Prof Dr, Laboratory of Inorganic Chemistry, Swiss Federal Institute of Technology (ETH), Switzerland
Transition metal oxides have been widely studied as promising electrode materials in Li-ion batteries. In principle, transition metal oxynitrides have better electrical conductivity and higher theoretical capacity than oxides. But they are investigated rarely due to their crystal structural instability and restricted chemical synthesis method. In this talk, synthesis and characterizations of nanoparticles of niobium (V) oxynitride, namely NbON, will be presented, and the electrochemical behaviors vs. lithium will be discussed as well. NbON has the baddeleyite (ZrO2) structure with monoclinic symmetry (space group P21/c). Nanoparticles of NbON were synthesized from thermal decomposition of ammolysized NbOCl3. By using elemental analysis and neutron diffraction, this compound was determined to be NbO1.3(1)N0.7(1) instead of NbON. Samples exhibiting the morphologically feature as 3-5 nm nano-sized particles were observed. Our study indicates that NbO1.3(1)N0.7(1) coated with 4.6 weight-% of carbon has much more stable and reversible cycling performance than the pure sample. When the cutoff potential was set at 0.05V and 1V, the measured capacities reached 500 Ah/kg and 100Ah/kg during the first discharge and then stabilized at 250 Ah/kg and 80 Ah/kg in subsequent cycling, respectively.
Hybrid Si/Ge-Carbon Nanotube Anodes for Lithium Ion Batteries
Brian J. Landi, PhD, Assistant Professor, Microsystems Engineering, Rochester Institute of Technology
Free-standing carbon nanotube (CNT) electrodes are shown to effectively support ultra-high capacity materials like Si and Ge for anodes in lithium ion batteries. The research has demonstrated both Si and Ge-CNT anodes with high reversible anode capacity (>1000 mAh/g), and using select metallization show excellent power density and modest cycling performance. The impact of this research is electrode technologies capable of enhancing today’s battery energy density to exceed 300 Wh/kg.
Lithium Intercalation in Nanoscale Electrode Materials: Silicon Nanostructures
Corey T. Love, PhD, Materials Engineer, U.S. Naval Research Laboratory
Many intercalation materials can only achieve high specific capacity at the nanoscale. Using nanostructured silicon as a model anode material, we show the dependence of lithium capacity on morphology and structure. The electrochemical performance of several silicon nanostructures (nanoparticles, nanowires, nanoporous architecture) will be presented. We are working to identify and control the mechanical and electronic stability of nanostructured silicon for improved cycle life performance. The ability of nanostructures to maintain stability compared to bulk materials will also be discussed.
Can Si Nano-Materials Provide High Energy Density in Li-Ion Cells without Cycle Life Compromise?
Yimin Zhu, PhD, Director of Battery and Fuel Cell, Nanosys, Inc.
Many attempts have been made to utilize silicon’s large storage capacity for lithium in practical Li-ion battery applications. Up to now, no efficient, durable and cost effective solution has been presented. Nanosys’ method of architecting novel materials for particular technical applications from the bottom up not only results in the desired specific materials properties but also allows for designing its materials to fit existing processes and manufacturing equipment. This presentation will show how, through the use of architected silicon nano-materials, the cell energy density can be dramatically increased simply by replacing graphite in the anode manufacturing process with our cost-effective Si composite while achieving high cycle efficiency and cycle life.
State of Health Assessment of Lithium Batteries from Thermodynamics Studies
Rachid Yazami, PhD, Professor, Principal Scientist, School of Materials Science and Engineering, Nanyang Technological University, Singapore
We have developed a new technique based on thermodynamics measurements performed on lithium half- and full-cells aimed at assessing the state of health (SOH) of electrode materials and of full batteries. Entropy, enthalpy and free energy state functions are determined by following the temperature dependence of OCV at different states of charge of the cell. Thermodynamics data are correlated with characteristic phase transitions taking place in anode and cathode materials, which are found to be SOH dependant. In the presentation we will show thermodynamics data collected with anode and cathode materials at different SOH. We will discuss on how the SOH assessment can be used to improve the battery safety and may be to proactively prevent battery thermal events.
Lowering Cost with Water: Green Manufacturing for Li-Ion Batteries
Jacob Muthu, PhD, Vice President, Research & Development, International Battery*
The large scale adoption of Li-ion batteries is limited due to cost and safety. Safety issues may be addressed by selecting the right combinations of chemistries. In this paper, we present results for large format Li-ion batteries manufactured using water based processes and how it reduces cost without affecting the cell performance as compared to traditional solvent based Li-ion battery manufacturing. Results focus on safe and environmentally friendly LiFePO4 chemistry.
*In collaboration with: M.Mamari, C.Crane, H.Georges
Developing Advanced Cathode Materials for High Performance Lithium Ion Batteries on the Large Scale via Atomic Coating
Jie Li, PhD, Principal Chemical Engineer, Argonne National Laboratory
Batteries for future electric vehicles will require high working voltage and long enough life time. Li-Mn-O Lithium ion battery is the most promising candidate because of its high output voltage and energy density. However, such a battery is prone to a chemical degradation, which severely prevents its wide applications. Surface modification of cathode materials to protect them from the electrolyte attack yet allow efficient charge transfer is expected to resolve the problem. In this talk, I will present our work on using the atomic layer deposition (ALD) method to address this problem. It is demonstrated that ALD coating on cathode particles can effectively enhance battery’s cycling performance yet with limited growth of cell impedance. Meanwhile, the experimental results also clearly indicate that too thick coating will lead to significant drop of battery capacitance. Moreover, a new coherently-controlled gas-fluidized bed technique has been developed to address a long-standing flow instability problem in a gas-fluidized bed reactor with ultrafine powders (dp<20 microns), which enables us to scale up such ALD-FB coating process cost-effectively. The impact of this new process on powder/battery processing industry will also be briefly discussed.
A Multi-Scale Modeling Framework for Li-Ion Batteries
John A. Turner, PhD, Group Leader, Computational Engineering & Energy Sciences, Oak Ridge National Laboratory
In this work, we present a multi-scale modeling approach for Li-ion batteries (LIB). The modeling framework consists of a volume averaged macroscopic model and a particle-resolved mesoscopic model. The macroscopic model relies on a rigorous volume averaging approach based on a single-domain formulation where complex geometries are incorporated with the numerical algorithms guaranteeing stability and convergence. In contrast to the multi-domain, pseudo-2D formulation with intermediate boundaries (anode/separator/cathode) based on the porous electrode theory, this unified formulation takes into account geometric multi-dimensionality (1D, 2D and 3D), electrode/electrolyte spatial arrangements and spatio-temporal variations in the physico-electrochemical properties. The mesoscopic model is based on fully resolved, statistically rigorous microstructure models of the battery electrodes using finite-volume technique with Cartesian cut-cell approach to account for the interfaces. We specifically study the solid state transport of Li in packed beds representative of typical electrodes and evaluate effective property and surface vs. bulk Li concentration relations. These scaled-up quantities are deployed in the macroscopic model described above. In this presentation, we describe the multi-scale modeling formalism with special emphasis on the influence of particle morphology (shape, size distribution) and particle-particle interactions on the transport (species, charge, and thermal) limitations and resulting performance implications in both the conventional and 3-D electrode architecture scenarios for the Li-ion battery.
*In collaboration with: Partha Mukherjee, Oak Ridge National Laboratory
Materials Design for the Lithium Conductive Material
Taku Onishi, PhD, Dept of Materials Chemistry, and The Center of Ultimate Technology for Nano-Electronics, Mie Univerisity, Japan
The perovskite-type transition metal compounds are well known to have the lithium ion conductivity. Under the operation temperature of lithium battery, the stable crystal structure is required for the high lithium ion conductivity. In this study, we theoretically designed the new lithium ion conductive perovskite with the thermally stable sturucture.
Lithium Batteries as Replacements for Lead Acid Applications
Jim Hodge, PhD, Chief Technical Officer, K2 Energy Solutions, Inc.
The fundamental voltage of the lithium iron phosphate (LFP) chemistry enables the manufacture of batteries with voltages closely matching those of lead-acid batteries. Consequently, LFP batteries can be fabricated that are "drop-in" replacements for lead-acid for a wide variety of applications. These LFP batteries offer significant advantages over lead acid in terms of both cycle life and capacity.
Lithium-Ion Battery Safety: Issues and Solutions
Ralph J. Brodd, PhD, Director, Kentucky-Argonne Battery Manufacturing Research and Development Center
An overview of the safety issues will be presented from the point of view of the chemistry, manufacturing and application in electronic as well as transportation applications. The major cause of safety incidents in batteries for electronic applications has been related to manufacturing defects in the materials and cell assembly. These are of the order of one incident in 5 million cells. New applications for electric and hybrid vehicles require a significant improvement in cell reliability by an order of magnitude over present practice as well as a means to isolate problem cells from the main stream in a battery pack. These and other issues to mediate problem cells will be discussed
Breakthrough in Large-Format Li-ion Battery Safety through Computer Simulation
Chao-Yang Wang, PhD, Distinguished Professor of Mechanical, Chemical, & Materials Science and Engineering, Director, Electrochemical Engine Center (ECEC), Co-Director, Battery & Energy Storage Technology (BEST) Center, The Pennsylvania State University
Currently whether or not a battery is safe is assessed by a set of abuse tests that are not as sensitive and accurate as they should be. We at Penn State ECEC, working with engineers at EC POWER as part of the DOE CAEBAT program, have developed computer models and tools to simulate processes of nail penetration, internal shorting, and thermal runaway in automotive Li-ion batteries with complex geometries. We shall show effects of nail diameter and penetration speed during partial or full penetration, location of shorting, and cell capacity on safety characteristics. We highlight fundamental insight into safety events and propose safety-enhancement strategies. Combined with experimental validation, computer simulation offers a possibility to design inherently safe batteries for automotive applications.
Abuse Tolerant Lithium-Ion Cells for Transportation Applications
Christopher J. Orendorff, PhD, Power Sources Technology Group, Sandia National Laboratories
As the scale of mobile lithium-ion batteries increases from consumer electronics to transportation scale, these higher energy systems will lead to an increased importance of safety and reliability. While engineering controls (cell and battery level) will play a significant role in the total system safety envelope, inherent cell chemistries can be advanced to demonstrate improved abuse tolerance for these technologies. This presentation will cover recent efforts to develop cathode, anode, separator, and electrolyte materials which lead to improving abuse tolerance in lithium-ion cells.
Safe Li-Ion Technologies for Transportation and Energy Storage
Karim Zaghib, PhD, Team Leader - Li-Ion Battery, Energy Storage and Conversion, Hydro-Québec Research Institute (IREQ), Canada
Hydro Quebec has tested several Li-ion battery technologies using the following electrode materials: LiCoO2, LiMn2O4, LiCo0.33Ni0.33Mn0.33O2 and LiFePO4 versus the graphite or Li4Ti5012. We will demonstrate the results of the safety tests (crash, nail penetration, short circuit, etc.) performed on these batteries. The ARC and DCS methods were used to study the safety of charged cathode materials and lithium intercalated anode materials. Among the tested systems, the batteries based on LiFePO4 are found to be the safest systems for the transportation and energy storage.
Safety of Lithium-Ion PHEV Cells: Cylindrical versus Prismatic
Brian M. Barnett, PhD, Vice President, TIAX LLC
The occurrence of safety-related field-failures has prompted large-scale recalls of lithium-ion battery packs in consumer applications. The severity of field-failures is forcing the industry and the research community to adopt new approaches to tackle safety. That is especially the case when even larger lithium-ion cells are being considered for transportation applications. For PHEV scale cells, there has been considerable debate regarding the relative merits of cylindrical versus prismatic (and pouch) cells with regard to safety, as well as performance. We have used simulations, supported by experiments, to help set a quantitative framework for consideration of relative safety of large format cylindrical and prismatic cells, and to help understand the conditions that favor thermal runaway following development of an internal short, the latter being the most frequent cause of safety incidents. Results for the relative safety of cylindrical and prismatic 33 Ah cells are presented and described. We also discuss the implications of these results for materials selection and consideration of various cell designs.
Working Toward a Fail-Safe Design for Large Capacity Lithium-Ion Batteries
Gi-Heon Kim, PhD, Kandler Smith, PhD, and Ahmad Pesaran, PhD, National Renewable Energy Laboratory
Lithium-ion batteries (LIBs) are believed to be a promising candidate for electric energy storage of electric drive vehicles due to their high power and energy density. However, violent incidents reported for this technology and consequent safety concern are the major obstacle for fast market acceptance of LIB powered electric vehicles. High temperature triggers exothermic decompositions of LIB components often resulting in violent failure of the system, known as thermal runaway of LIBs. Mature small capacity LIBs, used in applications such as consumer electronics and power tools, typically incorporate multiple layers of safety incident mitigation methods. LIBs for vehicle applications should be much larger in capacity and physical size than those for consumer electronics. Scaling-up of LIBs dramatically changes the responses of LIB system under safety incidents. Consequently, protection/mitigation technologies for small cell system against safety incidents, such as positive temperature coefficient (PTC), current interrupt device (CID), and shutdown separator, do not work properly with large format LIB cells. This paper will introduce NREL’s recent model/experimental investigation for a safety enhanced large battery design with features enabling early fault detection and electrical isolation of a fault.
Lithium Ion Failure Rates and Fire Protection Considerations
Celina J. Mikolajczak, PE, Senior Managing Engineer, Exponent
Lithium-ion battery technology has become endemic to the consumer electronics industry and is finding new applications in industrial and transportation sectors. As lithium-ion batteries get larger and are used to store greater amounts of energy, there is interest in assessing the risk of failure, developing strategies for failure mitigation. We will discuss failure modes and failure rates associated with un-used lithium-ion batteries (i.e. new batteries in storage, or in transit to end users) compared to failure modes and failure rates of batteries that have been placed into service. Then we will discuss some considerations for fire protection under these varying scenarios.
Challenges for Safety Standards for Lithium-Ion Cells
Laurie B. Florence, Primary Designated Engineer, Predictive Modeling and Risk Analysis Group, Corporate Research, Underwriters Laboratories Inc.
Safety Standards help promote the safe commercialization of products. However, in some cases such as with lithium-ion cells, when the technology is developing so fast and an understanding of potential failure modes is still an active area of research, there is a tremendous challenge to updating the safety standard. Tests that may show promise in a laboratory setting providing battery designers and researchers insights may not translate well as a new test for a safety standard. This presentation will describe the search for a new test method for battery safety standards to help address field failures of lithium-ion cells attributed to thermal runaway due to internal short circuit.
Active Thermal Management of Lithium Ion Batteries Using Flexible Graphite Heat Spreaders
Jonathan A. Taylor, R&D Engineer, Advanced Energy, GrafTech International
Thermal management systems promote excellent performance, durability and safety in large lithium ion batteries, but often add weight, volume, complexity, parasitic power consumption and cost to the system. Flexible graphite has a unique combination of properties that enable compact, lightweight, thermal solutions. In this paper, a flexible graphite-based active thermal management solution for prismatic lithium ion batteries is presented. The inventive design effectively manages cell temperatures despite being more lightweight and compact than conventional liquid-cooled systems.
Implications of Cell to Cell Manufacturing Variations on Potential Risk of Safety of a Lithium ion Battery
Shanthi Korutla, PhD, Director, Battery Cells & Advance Product Development, International Battery, Inc.
Safety concerns of lithium ion batteries are becoming more of a focus of the public’s attention. This has resulted in the ever increasing commercial use of LiFePO4 due to its intrinsic safety and chemical stability as cathode materials. Large format Li ion cells manufactured with aqueous processing of LiFePO4-based electrodes with a combination of water-soluble binders exhibited excellent tolerance under extremely abusive conditions such as induced short circuit, over discharge, over charge, nail penetration crush test, etc. that add to its superior electrochemical performance in normal use. In an increasing number of definitive parameters for cell selection are being used to build more effective Li ion battery pack, traditional parameters such as cell capacity, resistance and self-discharge etc. measurements do not provide enough information for optimum cell selection, particularly for large format cells that must meet high standards of abuse tolerance in addition to superior in electrochemical performance in a normal operation. Electrode and cell manufacturing process parameters plays an important role as well for safety risks. The paper addresses how the impact of cell to cell variation in a battery system affects both electrochemical performance and abuse tolerance behavior.
Failure Investigation of Li-Ion Batteries
Jian Xie, PhD, Professor of Mechanical Engineering, Lugar Center for Renewable Energy, Indiana University - Purdue University Indianapolis (IUPUI); and Yang Ren, PhD, X-Ray Science Division, Argonne National Laboratory
Lithium ion batteries (LIBs) have the highest specific energy and energy density among the different battery technologies. This high specific energy and energy density are desired for many applications, but are the potential causes of safety incidents, which could cause detrimental damage to valuable property and could even cost human lives. Therefore, the safety of LIBs is of a great importance to their application in portable electronics, electric and hybrid electric vehicles, and military devices and systems. To maintain safe operation of a LIB cell, it is necessary to monitor the state of health of that cell. In order to do so, LIB failure needs to be comprehensively investigated including failure modes, failure causes, signs of early failure, detection methods to catch early failure signs, etc. Then, a system should be developed to monitor the LIB state of health. We have formed a team of government, academia, and industry professionals to investigate the failure of LIBs. A comprehensive and systematic approach has been taken to study the failure mechanism. A synchrotron high-energy x-ray coupled with electrochemical testing was used to study the in situ structural changes of the electrode materials during the charge/discharge cycle. The anode MCMB was found to have a new phase of Li and C compounds formed after overcharge as well as a possible Li deposition. The in situ structural changes of the cathode were also studied. When over-discharging, the corrosion of the Cu current collector was found to be the major cause of LIB failure. The failure mechanism of LiFePO4 cell under overcharge and over discharge conditions have been elucidated from our experimental investigation. The signatures of failure have been identified experimentally. The model/algorithm has been developed for early warning detection. A detection system which can detect the early signs of failure has been developed. This work was supported by US Navy Warfare Center.
Thermally Stable Electrolyte for Li-Ion Cells
Ganesan Nagasubramanian, PhD, Sandia National Laboratories
Thermal instability of Li-ion cells is a key concern that delays their adoption for transportation applications. The pervasive thermal instability mainly stems from the organic electrolytes and that needs to be eliminated for wide-spread use. Several different approaches including addition of fire retardants, ionic liquids, fluoro compounds, etc. have been made to mitigate this propensity, however, only with a limited success. In this talk our results on Hydro Fluoro Ethers to eliminating this hazard will be discussed.
Diagnostic Tools Development for Understanding and Monitoring Overcharge
Corey T. Love, PhD, Materials Engineer, U.S. Naval Research Laboratory
Safe operation of lithium-ion batteries is significantly influenced by charge/discharge voltage boundaries and the stability of electrode/electrolyte interfaces. Three tools are being developed to detect and understand the detrimental effects of overcharging at the electrode and cell level. First, an in-situ impedance method shows significant changes in a commercial lithium-ion polymer cell charged above 4.4 V. Second, in-situ X-ray absorption spectroscopy detects structural changes and performance losses within LiFePO4 after repeated cycling. Lastly, we probe the solid electrolyte interface in overcharged electrodes using the surface sensitive "∆" XANES technique. Results will be presented and discussed as part of a broader effort towards the development of diagnostic tools for lithium-ion batteries.
Characterization of Battery Materials: A Battery Safety Perspective
Sanjay Patel, PhD, Director of Analytical Services at Evan Analytical Group (EAG)
A good understanding of the consistency of materials entering the battery manufacturing supply chain is essential, from both a regulatory, scientific and safety perspective. A number of different analytical methods are available, many currently in use, to the battery industry for materials characterization for various purposes. The long-term life cycle and performance of a battery pack can potentially be affected by the presence of unwanted impurities in electrode materials. Variation in electrode composition can result in changes to individual cell performance and affect the stability of the entire battery system. With recent demands from the automobile industry for improvements in battery performance together with stringent safety requirements, adequate understanding and successful monitoring of battery raw materials has become important across the industry. This presentation will review a number of different analytical methods, focusing on those that are well suited to the battery industry for monitoring raw materials for production control. Methods are available that simultaneously allow the measurement of a wide range of impurity levels, thus allowing manufacturers or other end users to determine the consistency of their supply chain and identify changes in raw material quality from their supplier or other changes caused at a particular manufacturing stage.
Judith A. Jeevarajan, PhD, Senior Scientist - Battery Office, NASA Johnson Space Center
NASA has collaborated with UL to define a standard for the simulation of internal short tests. The initial set of tests included testing a set of cells of an 18650 Li-ion cylindrical cell design using a crush test method and analysis of the indentation and cells using CT scan techniques as well as destructive physical analysis. The standard developed will include recommendations on crush rod diameter, rate of displacement of the crush rod, voltage drop limit conditions, state-of-charge of the cells, orientation of the cells, etc.
Abuse Testing of Lithium Ion Cells: Internal Short Circuit, Accelerated Rate Calorimetry and Nail Penetration in Large Cells (1 - 20 Ah)
Ann Edwards, PhD, Senior Scientist, and Kirby W. Beard, Porous Power Technologies; and David Wood,Wei Cai, Jianlin Li, Hsin Wang, Oak Ridge National Laboratory
Oak Ridge National Laboratory (ORNL) and Porous Power Technologies (PPT) are developing and testing large C/LiCoO2 cells with PPT’s advanced separators. Temperature resistant separators with non-woven web reinforcements and high levels of ceramic filler (to 90% wt.) have survived 220 deg. C temperatures and various abuse tests. Internal short circuit testing, using a new ORNL test protocol, has shown survivability under overcharge/compression testing. Additional destructive over-heating (accelerated rate calorimetry) and nail puncture safety tests were also conducted.
Safety Testing and Live Video of Large Li-Ion Batteries
Jasbir Singh, PhD, Managing Director, HEL Ltd, United Kingdom
Reliable safety testing of larger batteries and battery packs requires new devices that can handle the potential energy release but also provide the necessary precision to allow reliable prediction of performance. Also, many current testing protocols call for video evidence to accompany the traditional data as photographic evidence gives much needed extra insight. Traditional "ARC" type adiabatic calorimeters are not able to meet these demanding needs and this presentation will show data and videos from a custom designed Battery Testing Calorimeter to provide much needed expansion of "ARC" type data including the use of integrated “cyclers” to evaluate charging and discharging limits.
The BMS in Focus- Safety, Testing and Operational For Mobile and Fixed Installations
Ken Chisholm, Global Business Director, Vecture, Inc., Canada
The Battery Management System (BMS) is a critical issue in the safe and reliable operation of lithium re-chargeable chemistries. With smaller battery packs the BMS system is a significant cost adder whilst in larger systems such as GRID systems the BMS needs to manage multiple strings and many cells in series, interacting with the main control system, providing data and control signals. Testing the BMS and the battery packs has safety, reliability and cost implications. The test requirements for smaller, and usually much higher volumes, are very different from the test and integration requirements for large format systems. (i) Considering battery management systems (BMS), from small to large format with safety and performance in focus; (ii) Advances in testing techniques: (a) testing the one shot secondary system, (b) large format systems where operator safety and system integration are key requirements; (iii) Contribution of the BMS in data collection for predictive failure analysis and operational profiling; (iv) Mean time to repair (MTTR) in large format modular systems; and (v) High throughput test systems for the BMS and battery pack.
Battery Management Systems for Industrial Applications
Karl Vestin, PhD, Director of R&D, Lithium Balance A/S, Denmark
The adoption of Li ion battery technology to power industrial machines has driven the need for appropriate battery management and suitable Li Ion cells. The term industrial application is this context refers to the following areas: materials handling; cleaning machines; lifts and aerial devices; utility vehicles. These applications characterize themselves by being typically below 120 volts and utilizing relatively large capacity, low cost batteries often operating in harsh environments. Acute price sensitivity is another characteristic of this market. The role of the battery management in this environment is to provide safe battery operation, control of switching circuitry, SoC estimation and charger control. This differs from an automotive application where typically a CAN enabled vehicle control unit would be present to provide the high level system intelligence and logic. The BMS takes on this role providing direct control of the BDU (battery disconnect unit). The safety logic and providing information to the load, such as CAN messages outlining the recommended allowable discharge rate and regeneration rates from and to the battery at any given time may be required in some applications, in others where there is no CAN bus present the system still needs to provide SoC information, signaling and control to external devices such as chargers.
How to Test & Certify Electric Vehicle Supply Equipment (EVESE) for North America
Tom O’Hara, Intertek
You’ve designed your EV Supply Equipment (including charging stations and ancillary components) in-line with the regulatory standards that govern your product. Now you have a responsibility, in some cases mandatory, to have your product tested and certified (“listed”) by an independent body recognized for their competency in electrical or mechanical safety. This allows you to sell your products in North America, and allows installers, retailers and inspectors to feel comfortable about your product’s compliance to industry accepted safety standards. In the case of EV charging systems, Article 625 of the US National Electric Code (NEC) indicates that “all electrical materials, devices, fittings and associated equipment shall be listed or labeled”, specifically Paragraph 625.1 Scope – The provisions of this article cover the electrical conductors and equipment external to an electric vehicle that connect an electric vehicle to a supply of electricity by conductive or inductive means, and the installation of equipment and devices related to electric vehicle charging. Ultimately the local AHJs – “Authority Having Jurisdiction” (often electrical code inspectors) have the final say in the acceptance of equipment and electrical installations. And the NEC tells the AHJ that one way of knowing a piece of equipment is okay, is to look for the “listing mark” of an approved lab.
Extremely Sensitive Metallic Contaminant Detection System for Li-Ion Batteries
Saburo Tanaka, PhD, Professor, National University Corporation, Toyohashi University of Technology, Japan
We have developed the magnetic metallic contaminant detectors using multiple superconducting ultra-sensitive magnetic sensor SQUID for lithium ion batteries. The quality of lithium ion batteries can be deteriorated by the inclusion of tiny metallic contaminants. Outer dimension of metallic particles less than 50 micron in motion cannot be detected by a conventional X-ray imaging. We successfully realized the inspection system for a continuous sheet electrode or separator of a lithium ion battery with width of at least 70 mm. Small iron particles of less than 50 micron were successfully measured.
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