Electric-controlled pressure relief valve for enhanced safety in liquid-cooled lithium-ion battery packs

The liquid-cooled battery energy storage system (LCBESS) has gained significant attention due to its superior thermal management capacity. However, liquid-cooled battery pack (LCBP) usually has a high sealing level above IP65, which can trap flammable and explosive gases from battery thermal runaway and cause explosions. This poses serious safety risks and challenges for LCBESS. In this study, we tested overcharged battery inside a commercial LCBP and found that the conventionally mechanical pressure relief valve (PRV) on the LCBP had a delayed response and low-pressure relief efficiency. A realistic 20-foot model of an energy storage cabin was constructed using the Flacs finite element simulation software. Comparative studies were conducted to evaluate the pressure relief efficiency and the influence on neighboring battery packs in case of internal explosions, considering different sizes and installation positions of the PRV. Here, a newly developed electric-controlled PRV integrated with battery fault detection is introduced, capable of starting within 50 ms of the battery safety valve opening. Furthermore, the PRV was integrated with the battery management system and changed the battery charging and discharging strategy after the PRV was opened. Experimental tests confirmed the efficacy of this method in preventing explosions. This paper addresses the safety concerns associated with LCBPs and proposes an effective solution for explosion relief.(c) 2023 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press.