Experimental Analysis on the Thermal Characteristics of the Lithium-ion Battery During the Aging Cycles

This paper investigates the thermal characteristic and heat generation mechanism of the lithium-ion battery during the aging cycles. The surface temperature distribution and the thermal characteristic of the battery were analyzed based on the infrared images. Results indicated that the surface temperature distribution of the battery is greatly dependent on the state of charge (SOC). The endothermic peak caused by the entropy heat coefficient of the reversible reaction heat gradually disappears as the increase of the discharge rate. The negative electrode has the highest temperature during the discharge process. The temperature rise of the battery gets higher as the battery ages, that is, the total heat output of the battery increases. However, the reversible reaction heat of the battery has little change with the increase of the aging cycles. The results of thermal behaviors analysis are conducive to understand the safety management and build a reliable thermal model for high energy density lithium-ion battery.