KF HEader Logovvrqwrwtxxycaavfzvvysszfzwcrrs

Battery Safety

Battery Safety 2016
Integrating Lithium Battery Safety Designs for Increasing Energy Demands
November 3-4, 2016 | Hyatt Regency Bethesda | Bethesda, MD

Final Agenda

Innovations continue to boost the energy storage capability of lithium-ion batteries (LIBs). These innovations are also expanding applications, consumer use, transport and regulations. Higher energy and higher use lead to higher risk. Thus, the task of implementing effective safety strategies falls on regulatory authorities, cell manufacturers, R&D engineers and forensic scientists. Accurate tests and models are critical for predicting and controlling the complex electrochemical, thermal and mechanical behavior of lithium-ion batteries while regulations are required for safe transport. The Battery Safety 2016 conference continues this vital dialogue.

Wednesday, November 2

5:00 pm Conference Registration

5:30-6:30 Welcome Reception in the Exhibit Hall with Poster Viewing

Thursday, November 3

8:00 am Morning Coffee

8:30 Organizer’s Welcome

Mary Ann Brown, Executive Director, Conferences, Knowledge Foundation, a Division of Cambridge EnerTech

8:35 Chairperson’s Opening Remarks

Brian Barnett, Ph.D., Vice President, CAMX Power

8:45 KEYNOTE PRESENTATION: Solid-State Batteries, the Ultimate Solution to Battery Safety

Eric_WachsmanEric D. Wachsman, Ph.D., Professor & Director, University of Maryland Energy Research Center; William L. Crentz Centennial Chair, Energy Research, University of Maryland

We have developed intrinsically safe, all-solid-state Li-ion batteries (SSLiBs) by incorporating high-conductivity garnet-type solid Li-ion electrolytes into tailored tri-layer microstructures, by low-cost fabrication techniques, to form electrode-supported dense thin-film (~10μm) solid-state electrolytes. The microstructurally tailored porous garnet scaffold support increases interfacial area, overcoming the high impedance typical of planar geometry SSLiBs resulting in an area-specific resistance of only ~2 Ωcm-2. The unique structure further allows for Li-metal high depth of discharge ability without cycling fatigue. Results for Li-metal anode/garnet-electrolyte-based batteries with a number of different cathode chemistries will be presented.

Engineering Safety for Diverse Applications

9:30 Examining Chronic vs. Acute Safety Concerns for Wearable Batteries

Daniel Steingart, Ph.D., Assistant Professor, Mechanical and Aerospace Engineering, Andlinger Center for Energy and the Environment, Princeton University

10:00 New Understanding of Energy Distributions Exhibited during Thermal Runaway of Commercial Lithium-Ion Batteries Used for Human Spaceflight Applications

William_WalkerWilliam Walker, Heat Transfer Analyst, Thermal Design Branch, NASA Johnson Space Center

Lithium-ion batteries provide low mass and energy-dense solutions necessary for space exploration, but thermal-related safety concerns impede the utilization of Li-ion technology for human applications. Experimental characterization of thermal runaway energy release with accelerated rate calorimetry (ARC) supports safer thermal management systems. “Standard” ARC setup provides means to measure the addition of energy exhibited through the body of a Li-ion cell. This study considers the total energy generated during thermal runaway as distributions between cell body and hot gases via inclusion of a unique secondary enclosure inside the ARC apparatus. This closed system not only contains the cell body and gaseous species, but also captures energy release associated with rapid heat transfer to the system unobserved by measurements taken on the cell body. Experiments include Boston Power Swing 5300, Samsung 18650-26F and MoliCel 18650-J Li-ion cells at varied states-of-charge. An inverse relationship between state-of-charge and onset temperature is observed. Energy contained in the cell body and gaseous species are successfully characterized; gaseous energy is minimal. Significant additional energy is measured with the heating of the secondary enclosure. Improved ARC apparatus including a secondary enclosure provides essential capability to measuring total energy release distributions during thermal runaway.

10:30 Coffee Break in the Exhibit Hall with Poster Viewing

11:00 Battery Safety and Mobile Power Grid

Khosrow_NematollahiKhosrow (Nema) Nematollahi, Ph.D., Chairman and CTO, Renewable Energy, Advanced Renewable Power LLC

We present advanced electrochemical, electrothermal, thermal-fluid, ballistic impact, shock, vibration, and drop test modeling and simulation for cells, modules, packs, and mobile power grids related to transit buses. We also discuss an advanced thermal management system to control thermal runaway and extend the safety and life of batteries, as well as an advanced armor composite to protect against bullet, blast, and rod penetration.

11:30 Effect of Impact and Mechanical Deformation on Lithium Battery Technology

Nasrin_Shahed_KhahNasrin Shahed Khah, Research Scientist, Electrochemical Engineering Group, Warwick Manufacturing Group, University of Warwick

The automotive industry is increasingly moving towards further electrification involving integration of lithium batteries. Vehicles regularly experience acceleration and deceleration during impact, resulting in small mechanical deformation of the lithium batteries. These impacts may not have an immediate effect, but actually cause accelerated ageing. During this work, commercial-grade lithium batteries were studied after experiencing acceleration and deceleration during impact within a drop tower. The internal resistance and capacity of these cells were then monitored for a period after impact.

12:00 pm Sponsored Presentation (Opportunity Available)

12:30 Session Break

12:45 Luncheon Presentation (Sponsorship Opportunity Available) or Enjoy Lunch on Your Own

1:15 Session Break

Failure Analysis

2:00 Chairperson’s Remarks

John A. Turner, Ph.D., Group Leader, Computational Engineering and Energy Sciences, UT-Battelle / Oak Ridge National Laboratory (ORNL)

2:05 FEATURED PRESENTATION: Examples of Implementation of Short Detection for Battery Safety

Brian_BarnettBrian Barnett, Ph.D., Vice President, CAMX Power

We have developed multiple, distinct, noninvasive and chemistry-agnostic technologies for sensitive early detection of internal shorts in Li-ion batteries before the shorts pose a thermal runaway threat. Applications of these technologies, which are ready for implementation in battery systems, include in-pack monitoring for safety and reliability, QC in cell manufacturing processes and cell screening prior to pack assembly. This talk illustrates examples of implementation of short detection technologies.

2:35 Three Electrode-Based Battery Failure Analysis

Yinjiao_XingYinjiao (Laura) Xing, Ph.D., Research Associate, CALCE, University of Maryland

To relate the attributes of each electrode to the performance of a full lithium-ion cell, the data interpretation for each electrode is required. A three-electrode cell system provides a solution to collect the data of each electrode by adding a reference electrode. Failure analysis can also be conducted after disassembly of the three-electrode cell. This study presents a methodology for commercial cell failure analysis by using a three-electrode cell setup.

3:05 Selected Oral Poster Presentation: Thermal Runaway Cell-to-Cell Propagation in Lithium-Ion Batteries

Bengt-Erik Mellander, Ph.D., Professor, Department of Physics, Chalmers University of Technology, Gothenburg, Sweden

Lithium-ion batteries have many advantages such as a high energy and power density, which make them the premium choice as a power source for many applications. There are, however, some concerns regarding the safety aspects of these batteries, as thermal runaway can have severe consequences, especially if the event will propagate cell to cell. In order to investigate these questions, abuse tests have been performed using an external heat source in the form of a propane burner to experimentally study cell-to-cell propagation of a thermal event and a model has been developed to simulate the temperature development in the neighborhood of a cell that undergoes a thermal runaway. The risks for a spreading thermal event in a battery pack as well as means to mitigate these are discussed.

3:20 Selected Oral Poster Presentation: Mechanism of the Entire Overdischarge Process and Overdischarge-Induced Internal Short Circuit in Lithium-Ion Batteries

Rui Guo, Research Scientist, Powertrain Control Group, Department of Automotive Engineering, Tsinghua University

Lithium-ion batteries connected in series are prone to be overdischarged. Overdischarge results in various side effects, such as capacity degradation and internal short circuit (ISCr). However, most previous research on the overdischarge of a cell was terminated when the cell voltage dropped to 0 V, leaving the further impacts of overdischarge unclear. We investigate the entire overdischarge process of large-format lithium-ion batteries by discharging the cell to 100% state of charge (SOC). A significant voltage platform is observed at approximately 12% SOC, and ISCr is detected after the cell is overdischarged when passing the platform. The scanning electron microscopy (SEM) and X-ray diffraction (XRD) results indicate that the overdischarge-induced ISCr is caused by Cu deposition on electrodes, suggesting possible Cu collector dissolution at the voltage platform near 12% SOC. A prognostic/mechanistic model considering ISCr is used to evaluate the resistance of ISCr, the value of which decreases sharply at the beginning of ISCr formation. Inducing the ISCr by overdischarge is effective and well controlled without any mechanical deformation or the use of a foreign substance.

3:35 Refreshment Break in the Exhibit Hall with Poster Viewing

Models, Sensors & Safety

4:15 FEATURED PRESENTATION: Balancing Accuracy and Computational Cost in Battery Simulation

John_TurnerJohn A. Turner, Ph.D., Group Leader, Computational Engineering and Energy Sciences, UT-Battelle / Oak Ridge National Laboratory (ORNL)

As we increasingly explore complex 3D battery architectures, simplified models are becoming inadequate. Fortunately, computational resources continue to expand, enabling more accurate models to be used to explore and optimize designs. We discuss the computational cost and benefits of removing simplifying assumptions in models, with examples demonstrating when simplified models are inadequate and coupled, fully 3D models become necessary.

4:45 FEATURED PRESENTATION: Polymer Foil-Embedded Photonic Sensor for Battery Safety

Wolfgang_SchadeWolfgang Schade, Ph.D., Professor & Department Head, Fiber Optical Sensor Systems, Fraunhofer Heinrich Hertz Institute; Department Head, Applied Photonics, IEPT, Clausthal University of Technology

Strain measurements on housing materials of prismatic lithium-ion battery cells performed by optical fibers enable interesting possibilities for in situ monitoring the state of charge as well as aging effects and therefore offer high potential for enhanced battery safety. New optical printing and processing techniques in polymer films allow integration of such sensor devices directly into the polymer housing material of the battery. First results will be shown and discussed.

5:15 FEATURED PRESENTATION: Operando Diagnostics of Li-Ion Batteries

Michael_ToneyMichael F. Toney, Ph.D., Synchrotron Materials Sciences Division Head & Professor, Photon Sciences, Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Center, Stanford University

To improve the safety in batteries, it is important to follow the process that initiates and leads to battery failures which can result in unsafe conditions. I explain how X-ray-based diagnostics (spectro-microscopy and diffraction) can be used to follow, in realistic battery environments and in real time, charge and discharge processes and the resulting changes in electrode structure and morphology.

5:45 Close of Day and Dinner Workshop Registration

6:00-9:00 Dinner Workshop*

W3: Lithium Battery Transportation Regulations – Eliminating the Complexity and Improving Safety Based on Sound Science - View Details

Panel of Facilitators: Daphne A. Fuentevilla, Ph.D., Engineer, Advanced Power and Energy Group, NSWC Carderock, U.S. Navy

Steve Hwang, Ph.D., Chemist, U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration (U.S. DOT – PHMSA)

George A. Kerchner, Executive Director, PRBA – The Rechargeable Battery Association

Kevin Leary, Transportation Regulations Specialist, U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration (U.S. DOT – PHMSA)

* Separate registration required.

Friday, November 4

8:00 am Battery Breakfast Breakout Discussion Groups

Grab coffee and breakfast and join a discussion group. These are moderated discussions with brainstorming and interactive problem solving, allowing conference participants from diverse backgrounds to exchange ideas and experiences and develop future collaborations around a focused topic.

View Breakout Discussion Details

Designing Safety with Battery Management Systems

9:15 Chairperson’s Remarks

Rengaswamy (Srini) Srinivasan, Ph.D., Principal Professional Staff Scientist, Research and Exploratory Development, Applied Physics Laboratory, Johns Hopkins University

9:20 Ensuring Thermal Safety with an Internal Temperature-Enabled Battery Management System

Rengaswamy_SrinivasanRengaswamy (Srini) Srinivasan, Ph.D., Principal Professional Staff Scientist, Research and Exploratory Development, Applied Physics Laboratory, Johns Hopkins University

Thermal safety is the topmost obstacle for any lithium-ion (Li-ion) Battery Management System (BMS). Surface-mounted external-surface sensors obfuscate the safety issues. Temperature sensors such as fiber Bragg grating (FBG) are invasive and degrade. Noninvasive Battery Internal Temperature Sensors (NIBITS) have the best chance yet to enable a BMS to safeguard Li-ion batteries. We present a NIBITS-enabled BMS that is agnostic to battery chemistry and Ah-capacity, for multi-cell Li-ion batteries.

9:50 Selected Oral Poster Presentation: Evaluation of External Short Circuit Performance of NCA and NCM Li-Ion Batteries for the Design of a Safer Protection Mechanism

Akos Kriston, Ph.D., Research Fellow, European Commission, Joint Research Centre, Directorate for Energy Transport and Climate

The aims of this study are to analyze the short circuit performance and to identify the governing phenomena. New insights are provided on the short circuit behavior of Li-ion batteries and to designing safer protection devices. The results of series of short circuit tests on 3-electrode coin size cells with 5 mAh capacity and on 10 Ah pouch cells comprising graphite-NCA and NCM active materials are presented. The short circuit tests were monitored by high-speed data acquisition of current, temperature and potential on all cells. Furthermore, synchronized audio, IR and visual video were recorded during the pouch cell tests. Subsequently the anode, cathode and separator of the abused pouch cells were characterized by Scanning Electron Microscopy (SEM), micro X-ray Computed Tomography and 3D profilometry. The analysis of the variation of current, potential and temperature indicates that the complex short circuit behaviour can be described by 3 regions. In the first region, the cell's double layer capacitance is dominant; therefore, the initial current (with a maximum C-rate of 200-300 at the lowest external resistance) depends mainly on the external short resistance. The extremely high current of the first region can destroy the cell's tabs and interconnections or can create local hot sports leading to internal short circuit. In the second region, the current drops significantly and mass transport becomes limits the current. The maximum temperature is reached in the mass transport limited region resulting in rupture, venting and electrolyte leakage only 200-300 s after the short was initiated. In the final, third region, the depletion of the active material continues and both, current and potential, drop to zero while temperature starts to decline due to heat dissipation to the environment. A simple method, which is able to match the tripping characteristics of the cell's passive and active protections with its external short circuit behaviour, is suggested.

10:05 Online Diagnosis of Lithium-Ion Batteries According to Surface Temperature Variation

Asmae_El_MejdoubiAsmae El Mejdoubi, Ph.D., Research Fellow, LUSAC Laboratory, Université de Caen Normandie and ENSAM, Université Moulay Ismail

I present a hybrid state-of-charge (SOC) and state-of-health (SOH) estimation technique for lithium-ion batteries according to surface temperature variation. The hybrid approach uses an adaptive observer to estimate the SOH while an extended Kalman filter is used to predict the SOC. In order to validate the proposed method, experiments have been carried out under different operating temperature conditions and various discharge currents.

10:35 Coffee Break

Thermal Considerations – Monitoring Gas Emissions

11:00 Fire Characteristics and Toxic Gas Emissions of Li-Ion Batteries

Fredrik_LarssonFredrik Larsson, MSc, Researcher, Electronics, SP Technical Research Institute of Sweden; Department of Physics, Chalmers University of Technology

The release of flammable and toxic gases is an important aspect of Li-ion safety. Results from fire abuse tests on commercial automotive Li-ion cells and on different electrolyte mixtures will be presented for different SOC and cell types. Results from some water mist firefighting will also be reported. Heat release rate and total heat release were measured as well as HF and POF3 emissions.

11:30 Gas Analysis in Lithium-Ion Cell Tested by Very High Temperature

Jian Dong, Ph.D., Senior Cell Development Engineer, SAFT SDD, SAFT America, Inc.

The high temperature chemistry cells developed in Saft will be tested from 60˚C to 125˚C. The gas will be harvested from the tested cells and analyzed by GC-MS to understand the aging mechanism.

12:00 pm Session Break

12:15 Luncheon Presentation (Sponsorship Opportunity Available) or Enjoy Lunch on Your Own

12:45 Session Break

Thermal Considerations – Modeling &
Managing Runaway

1:30 Chairperson’s Remarks

Judith Jeevarajan, Ph.D., Research Director, Electrochemical Safety, Underwriters Laboratories, Inc.

1:35 Multiphysics and Multiscale Characterization and Modeling of Thermal Runaway Events Pertaining to Fresh and Aged Li-Ion Batteries

Martin Petit, Ph.D., Electrochemical Engineer, Electrochemistry and Materials Department, IFP Energies Nouvelles, IFPEN

Among electrochemical storage systems, Li-ion batteries were found to be promising candidates for both electromobility and stationary applications. Nevertheless, Li-ion battery safety is still considered a critical issue due to thermal runaway potential hazard on the full value chain. Through an extensive experimental work and a physical modeling approach, the effect of aging on safety is investigated, for further practical applications to safety management.

2:05 Predicting Thermal Runaway from Self-Discharge Data

John_McHardyJohn McHardy, Ph.D., President, J McHardy LLC

Thermal runaway is a major factor in lithium-ion battery accidents but is difficult to characterize without knowing the kinetic parameters of underlying exothermic reactions. Laboratory measurement of reaction kinetics during thermal runaway can be hazardous, and the results may not apply to real world situations. Instead, we discuss the possibility of predicting the course of thermal runaway from kinetic parameters derived from battery self-discharge data at lower temperatures.

2:35 Safety Aspects of New and Aged 18650 Lithium-Ion Cells

Torleif_LianTorleif Lian, Chief Engineer, Maritime Department, Norwegian Defense Research Establishment (FFI)

The thermal responses of new and aged commercial lithium-ion 18650 cells have been studied during controlled heating (calorimetric techniques). The size, geometry and cell environment have been kept constant, while battery chemistries were varied. The results show that the highest heat rate does not necessarily correspond to the most severe physical result. Safety consideration based only on heat rates from different cathode chemistry will give a false basis for safety in the final application.

3:05 Thermal Stability of Lithium-Ion Battery Materials: A Kinetic Consideration

Stephan_HildebrandStephan Hildebrand, MSc, Research Associate, MEET Battery Research Center, University of Münster

To investigate the thermal stability of a material, adiabatic calorimetry in an accelerating rate calorimeter is applied. For the thermal decomposition of a material, kinetic rules are valid to describe and predict the self-heating rate curves. New cathode materials were synthesized and tested regarding its safety behavior. The kinetics during decomposition were determined to predict the safety behavior in a whole cell system.

3:30 Overview of ARL’s Optical-Based Diagnostic Techniques for Measurement of the Thermal, Pressure, and Chemical Evolution from Energetic Events Including an Overview of ARL Li-Ion Battery Vulnerability Efforts

Barrie_HomanBarrie E. Homan, Ph.D., Research Physicist, Explosive Effect Branch, U.S. Army Research Laboratory

The characterization of the pressure, temperature, and chemistry resulting from an energetic event leads to a more fundamental understanding of the underlying mechanisms controlling the behavior of energetic materials. Optical techniques have been developed to measure the evolution of these parameters resulting from the reaction of energetic materials producing temporally resolved, 2-dimensional maps without disturbing the flow. Lithium-ion batteries are becoming more prevalent in military systems due to their high-energy density. An overview of ARL's efforts in studying the flammability of these batteries will be presented.

4:00 Fire Suppressants for Lithium-Ion Battery Fires

Judith_JeevarajanJudith Jeevarajan, Ph.D., Research Director, Electrochemical Safety, Underwriters Laboratories, Inc.

Lithium-ion batteries are used increasingly in larger sizes (high voltage and high capacity) from automotive, aviation, underwater and stationary energy storage applications. The need to control and suppress battery fires created due to unexpected events is significant in the current environment. A study is being conducted on a few different fire suppressants to see their effectiveness in suppressing a lithium-ion battery fire. We present results of the study.

4:30 Close of Battery Safety Conference