In-situ characterization approach for heat-generating performances of a pouch lithium-ion battery

Abstract

The heat generated of the lithium-ion battery raises its own temperature, and accurately demonstrating the battery’s heat-generation is of significance for the battery pack’s thermal safety management. This work presents a novel thermal compensation method that accounts for heat loss, significantly enhancing the accuracy of heat generation assessments in large-format pouch batteries under both high and low temperature-rise conditions. The results show that the battery’s heat generation exhibits a U-shaped pattern under high temperature-rise conditions, while displaying an increasing tendency of “fast-slow-fast” under low temperature-rise condition. By considering heat loss, the current method achieves a 93.5% accuracy rate compared to measurements that omit this factor. Specifically, under low temperature-rise conditions, the heat generations at discharge rates of 0.7C, 1.0C, and 1.2C are 4.74%, 11.56%, and 16.25% higher than those under high temperature-rise conditions, respectively. Accurately and cost-effectively, present method to measure battery heat-generation without resorting to costly equipment. The results would be valuable for one to characterize battery’s heat-generating performance under the conditions of high and low temperature-rises.