Experiment study of pseudo-passive heat removal system for power battery thermal runaway propagation inhibition

Abstract

Approximately 41% of power battery thermal runaway propagation accidents happen at rest conditions; hence, developing passive technologies to stop such accidents is highly necessary. Existing passive power battery thermal runaway propagation inhibition approaches involve thermal insulation. However, the relatively large thermal resistance is incompatible with thermal management, which is a bottleneck that needs to be addressed properly. In this paper, a pseudo-passive heat removal system is proposed, to be combined with less thermal resistance to cut off thermal runaway propagation. The pseudo-passive heat removal system is based on a pump-driven cooling and thermoelectric conversion process, that is, the latter converts battery heat generation into electric energy to power the former. A prototype was developed, and its operational characteristics were studied. First, steady performance of pump-driven cooling processes with large temperature differences were analyzed. Second, the transient processes of the prototype for different internal electric-energy allocations were compared. It was found that the system heat removal rate in the working mode in which more energy was assigned to the pump-driven cooling process was 35% better than the rate when more energy was assigned to the thermoelectric conversion process. The novelty of this study lies in proposing a pseudo-passive power battery heat removal system and highlighting the effects of key parameters. This study provides new insights into heat removal from power batteries and will be helpful in enhancing electric vehicle safety.