Lithium-ion battery fires: 7 solutions for improved safety
5. Added protection: strengthening the mechanical battery enclosure
I really do not want to say much in this area because having a strong battery enclosure or surrounding case might be the last thing we really need for battery safety. I will only comment on the fact that some sort of mechanical enclosure needs to be used to possibly house the battery and any fire retardant material along with a connection to a possible cooling system. These are all mentioned in this article, so the actual case is secondary to all of the other suggestions mentioned, but nonetheless needed.
Pressure buildup/cell venting is deemed the most common response that is seen in Lithium-ion batteries that are subjected to abuse or poor design (Figure 3).
Figure 3 Mechanical damage due to a crush of short circuit is one of the many areas that can be simulated in the design and manufacturing phase with any changes tested before customers get the battery. (Image courtesy of Reference 6)
A good example of better modeling that may have helped the Samsung case (and I am a “Monday morning quarterback” here) would be better modeling in the area of venting of pouch cells, as can be seen in the National Renewable Energy Laboratory slideshow in 2013 (Reference 6). This tutorial integrated mathematical models for individual factors that could contribute to the swelling of Lithium-ion cells and related the pressures within those cells to the mechanical strength of the case. This modeling would lead to the identification of problems in the cell manufacturing process and proper sealing of the battery case.
The goal here was to create a single simulation tool, for battery designers and manufacturers that employ batteries in their products, that would help identify any material limitations as well as assess any design modifications in battery/cell fabrication.
I wanted to mention this as a possibility for more research in the future. Present research studies have shown that the use of ionic fluids, gel polymer electrolytes, or solid-state electrolytes instead of volatile carbonates or additives can lower the flammability of the battery electrolyte. The drawback preventing their use is lower conductivity which leads to poorer battery performance in a time when the need for more efficient batteries is a must, as I mentioned at the beginning of this article. Consumers need better functionality in their smartphone, especially as we approach 5G. More research can be done in this area to improve upon the battery efficiency with better and less flammable electrolytes or additives which can significantly improve safety.
In closing, I have hopefully provided some solid tech ideas that will be insightful to engineers and product designers in the prevention of future fires and explosions in Lithium-ion battery operated products. Until then, I feel very strongly that the FAA needs to provide more than a ‘strong warning’ to passengers with devices that contain these batteries and freight companies that ship anything with a Lithium-ion battery to ensure the safety of air travel. The FAA or other government organizations (Canada has some really good guidelines) need to trace Lithium cells and batteries to their source and allow only trusted and reputable manufacturers’ batteries to be allowed on an aircraft. Authorities must demand that Lithium-ion cells and batteries be tested and certified by a reputable and recognized organization (The United Nations has some good suggestions).
EDN readers are a group of highly talented engineers and designers and can make a difference. Let me know what you think by sharing your comments below with our esteemed audience members so we can start a positive discussion that will lead to future improved safety results in Lithium-ion battery usage.
- Using liquid coolant
- Fire-retardant thermal insulation
- Improved cathode materials
- Smart multi-functional fluids
- Strengthening the mechanical battery enclosure
- Better modeling
- Lower electrolyte flammability
- Application of Fluid Protection for Increased Safety and Efficiency of Lithium-Ion Battery and Electronic Devices, Nicholas Johnson, William Meyring PE, Paul Rivers PE, on the National Fire Protection Association (NFPA) site, 2016
- Smart multifunctional fluids for Lithium Ion batteries: Enhanced rate performance and intrinsic mechanical protection, J.Ding, T. Tian, Q. Meng, Z. Guo, W. Li, P. Zhang, F.T. Ciacchi, J. Huang, W. Yang, Scientific Reports 3, Article number: 2485, 2013
- Thermal safety of lithium-ion batteries with various cathode materials: A numerical study, Peng Peng, Fangming Jiang, Laboratory of Advanced Energy Systems, Guangdong Key Laboratory of New and Renewable Energy Research and Development, CAS Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences (CAS), Guangzhou 510640, China, Elsevier 2016 (May need payment or membership on ResearchGate)
- Quantification of Lithium-ion Cell Thermal Runaway Energetics, Christopher J. Orendorff, Joshua Lamb, Leigh Anna M. Steele, Scott W. Spangler, and Jill Langendorf Power Source Technology Group Sandia National Laboratories P.O. Box 5800 Albuquerque, New Mexico 87185-MS0613, January 2016.
- Thermal Runaway and Safety of Large Lithium-Ion Battery Systems, Nicolas Ponchaut, Ph.D., P.E. Kevin Marr, Ph.D., P.E. Managing Engineer Sr. Engineer Francesco Colella, Ph.D. Vijay Somandepalli, Ph.D., P.E. Sr. Associate Managing Engineer Quinn Horn, Ph.D., P.E. Principal Engineer, Exponent Inc. Natick, MA 01760
- Modeling Lithium Ion Battery Safety: Venting of Pouch Cells, S. Santhanagopalan, C. Yang, A Pesaran, National Renewable Energy Laboratory, July 2013
- How Electrolytes Influence Battery Safety, E.P. Roth, C.J. Orendorff, The Electrochemical Society Interface, 2012
- Special report: Beyond the exploding battery
- Samsung recall: Tech solutions to enhance lithium-ion battery safety
- Thermal design: Get the heat out of the electronics
- Boeing 787 and Lithium Ion battery failure
- Teardown: High-voltage Li-ion battery stack management - the drive for safe power
- Runaway Lithium-Ion batteries