Safety warning of lithium-ion battery energy storage station via venting acoustic signal detection for grid application

Lithium-ion battery technology has been widely used in grid energy storage for supporting renewable energy consumption and smart grids. Safety accidents related to fires and explosions caused by LIB thermal runaway frequently occur, seriously threatening human safety and hindering further applications. Here we propose a safety warning method for MW-level LIB stations through venting acoustic signal, with the advantages of fast implementation, high sensitivity and low cost. To verify the effectiveness of the above method, an overcharge-induced thermal runaway experiment is conducted using commercial battery cells and modules in a real energy storage cabin. The results show that thermal runaway could be accurately and quickly detected through the venting acoustic signal, and timely actions can effectively suppress the development of thermal accumulation. Considering that many kinds of interference noise exist, a denoising method based on spectral subtraction is constructed after analysing the noise. To eliminate similar interference signals after denoising, an acoustic signal recognition classifier is built using the XGBoost model. The recognition accuracy can reach 92.31%. The above safety venting method based on venting acoustics provides a new approach to improve the safety level of grid energy storage.