In Situ Diagnosis and Control of Li-Ion Batteries for Enhanced Safety

Abstract

Safety of Li-ion batteries remains a critical challenge due to their high energy density and use of flammable electrolyte. The challenge is further propelled by their ever-increasing and demanding applications in electric vehicles (EVs). Recent high-profile events involving electric cars and airplanes that employ Li-ion batteries as main or auxiliary power sources lend further urgency to enhanced Li-ion battery safety. We obtained insights of nonuniform temperature distributions in Li-ion battery cells through in situ diagnosis1. Inspired by those insights, we developed a reaction temperature sensing (RTS)-based control technique to enhance Li-ion battery safety. The RTS-based control is demonstrated to shut down an external short circuit event 3 times earlier than conventional surface temperature- based control and effectively prevent cell damage2. We will apply the RTS-based control and in situ diagnosis of temperature distributions to other challenging safety scenarios including internal short circuit. The progress will be presented. Reference 1. G. Zhang, L. Cao, S. Ge, C.Y. Wang, C. E. Shaffer, C. D. Rahn, In situ measurement of radial temperature distributions in cylindrical Li-ion cells, Journal of The Electrochemical Society,2014, 161 (10): A1499-A1507 2. G. Zhang, L. Cao, S. Ge, C. Y. Wang, C. E. Shaffer, C. D. Rahn, Reaction temperature sensing (RTS)-based control for Li-ion battery safety, Scientific Reports, under review