Integrated liquid-cooled battery module with dual functions: Thermal runaway suppression and early warning via flexible pressure sensors

Abstract

The demand for enhanced thermal safety performance in energy storage battery systems is increasingly rigorous. In practical applications, the management system with multi-function integration features, especially the combination of passive thermal management and active early warning, shows great potential. In this study, a novel large-capacity battery module is designed and assembled, integrating flexible pressure sensors for active warning function without compromising system structure. For thermal management, a cold plate/aerogel pad coupled structure is established and tested with a circulation refrigeration system under an overheating thermal runaway (TR) experiment system. First, the performance of cold plates and/or aerogel pads is compared, with cold plate flow rates of 0.3 L/min and 1 L/min, and an aerogel pad thickness of 1.5 mm. The results demonstrate that both cold plates and aerogel pads independently demonstrate the ability to prevent TR propagation. A comparative analysis of heat transfer power from the TR battery to the adjacent battery reveals that the aerogel pad is critical for significantly reducing heat transfer, irrespective of the presence of a cold plate. The aerogel pad reduces the peak heat transfer power by 59 % compared to the blank module. Additionally, the integration of only 0.46 mm-thick thin-film pressure sensors enables pressure distribution detection across the battery surface during TR process. The maximum pressure (P_max), representing the highest pressure point across the entire battery surface, is identified as an excellent early warning signal. In a typical energy storage battery module using cold plate and aerogel pads, the P_max early warning for TR precedes temperature, voltage, and expansion force signals by 1212 s, 1158 s, and 72 s, respectively. The P_max peak reaches 1114 kPa and lasts for 138 s, enhancing the reliability in preventing false alarms.