Estimation of temperature distribution of LiFePO4 lithium ion battery during charge-discharge process

摘要

Thermal issues of lithium ion batteries are key factors affecting the safety, operational performance, life, and cost of the battery. An electrochemical-thermal coupling model based on thermoelectrochemical basic data was established to investigate the thermal behavior of LiFePO4 lithium ion battery. In this paper, the finite element method was used for simulation of temperature field distribution inside battery during charge-discharge process, and the influence of the charge-discharge rate and ambient temperature on the distribution of temperature field was summarized. The results showed that the highest temperature of battery was recorded at the junction of negative and separator during charge-discharge process. At a low discharge current, the modeling results agreed well with the experimental data. When the ambient temperature was 303.15 K, the maximum temperatures inside the battery were 304.60, 304.83, 306.55, and 309.96 K for 0.1, 0.2, 0.5, and 1.0 C charge-discharge rates, respectively. If the ambient temperature increased to 323.15 K, the maximum temperatures were increased by 24.96, 27.91, 33.18, and 32.59 K for 0.1, 0.2, 0.5, and 1.0 C charge-discharge rates, respectively, and the homogenous temperature field distribution inside the battery was worse.