Analysis of the Thermal Conditions in a Lithium-Ion Battery Pack at Reduced Heat Exchange Rate with the Environment

The use of chemical current sources (CCS) in large stationary electrical energy storage systems (EES) is impossible without solving the problem of their thermal runaway. The runaway may be due to exponential temperature rise in major operating components of the battery. One of the factors that increase electrode and electrolyte temperature in a battery is its lower heat exchange with the environment. This study performs a numerical analysis of the thermal conditions in a Li-ion battery pack at moderate values of external factors affecting the thermal runaway and typical discharge rates for this type of CCS. Thermal resistance between Li-ion battery and the battery pack case was found to greatly reduce heat exchange with the environment. The temperature difference across the battery pack in a practically significant range of variables was from 2 to 16 degrees C. At the same time, the characteristic temperature exceeded in a number of cases its regulated limit value, which created the risk of the battery's thermal runaway.