Design of thermal management system for lithium battery at low temperature

The battery capacity of lithium battery will decay at low temperature, and the battery performance will seriously decline at extremely low temperature, and the electrolyte will also freeze. Therefore, lithium batteries need to be preheated at low temperature. This paper selects 22 Ah lithium iron phosphate battery as the research object. The preheating scheme of PTC aluminum plate heating plate for lithium battery was designed by thermal parameter calculation and simulation method. The preheating scheme was optimized by changing the number (2, 3 and 4 pieces) and size (120%, 80% and 60% lithium battery size) of PTC heating plate. The results show that when heating 6 pieces of 22 Ah lithium iron phosphate battery, the preheating effect of 3 pieces of PTC heating plate close to the size of lithium battery is the best.