Safety study of soft pack lithium iron phosphate batteries under different spherical indentation states

In recent years, lithium battery explosion and fire accidents caused by collisions of new energy electric vehicles have occurred frequently, and the safety performance of lithium batteries under mechanical abuse has attracted much attention. To investigate the safety performance of lithium-ion batteries under compression conditions, this study conducted an in-depth investigation of commercial soft pack lithium iron phosphate batteries and discussed the effects of different states of charge, indenter diameter, and compression position on battery safety. Real time monitoring of the temperature evolution of the battery surface during compression using an infrared thermal imager, recording of voltage changes using a blue electric system, and testing of internal resistance changes using a precision internal resistance meter. This study provides practical reference value for understanding the heat generation behavior and safety assessment of thermal runaway in lithium iron phosphate batteries under spherical indentation.