Underwriters Laboratories collaborated with the Centre for Automotive Research & Tribology (CART) in IIT-Delhi along with IEEE Computational Intelligence Society Delhi Chapter and IEEE PELS-IES Delhi Chapter, to host a virtual lecture on 22 Sept, 2020. This 60-minute lecture was presented by Dr. Judy Jeevarajan, Research Director of Electrochemical Safety for Underwriters Laboratories and the topic was ‘Lithium-ion Batteries – Basics of Chemistry and Safety’.
Lithium-ion (Li-ion) batteries, first commercialized in the early 1990s, provide power in a myriad of ways in our lives. They are ubiquitous: medical devices, cellphones, computers, power tools, drones, electric vehicles, airplanes, space applications and grid energy storage. More than a billion rechargeable Li-ion battery cells are produced each year for the consumer electronics market alone. This dependence will only increase as new technologies require lightweight, powerful energy supplies. But while these batteries provide a lot of benefits, they also come with safety challenges.
Li-ion cells have the highest energy density of the commercially available rechargeable cell chemistries and associated with this high energy density is also a very high propensity for these batteries to go into thermal runaway under off-nominal and abusive conditions. Additionally, as the energy and power density of Li-ion batteries steadily increase in response to market demands, safety continues to remain a critical challenge. Therefore, cells and batteries need to be designed for performance and safety. Equally important are the safety tests and standards for various end-use cases and environmental conditions.
In this session, Dr. Jeevarajan provided a basic understanding of the Li-ion battery chemistry as well as the causes of hazards and the challenges that come with the growing size of the batteries of this chemistry.