An experimental and numerical examination on the thermal inertia of a cylindrical lithium-ion power battery

Abstract

Thermal issues are increasingly critical for the scaling-up and integrated deployment of lithium-ion batteries (LIBs). To make battery temperature control more accurate, a concept of thermal inertia was proposed to cylindrical power batteries in the current study. Experimental results showed that the thermal inertia of the battery can greatly affect the thermal behavior during battery discharging process, based on which a battery thermal model was created by COMSOL Multiphysics with infrared imaging technology adopted to experimentally investigate the thermal inertia for a LiFePO4 (LFP) battery. It is evidenced that the model and the corresponding simulation can provide helpful guidance for the thermal behavior control and improve thermal performance. Furthermore, the temperature distribution and variation of the slack period (after discharge) were studied, including internal temperature, surface temperature and temperature difference. Results showed that the battery radius (R) and discharge rate (C) were the major factors that influenced the thermal inertia. In addition, a thermal inertial calculation model was proposed for predicting battery thermal inertia under different operating conditions.