Investigations of gas for Ni-rich/Si-C lithium ion batteries under high temperature condition

HU Xiaoyan

doi:10.19996/j.cnki.ChinBatlnd.2024.05.002

Abstract：The investigations have been mainly focused on the cycling capacity of Ni-rich LiNi0.8Co0.1Mn0.1O2(NCM811)cathode and silicon carbon(Si-C)anode batteries,and there are few studies on the gas generation affecting the reliability of batteries,especially the overall researches on the gas generation and mechanism during different SOCs storage and cycle processes.In this work,the drainage method has been employed to measure gas volume,gas chromatography-mass spectrometry(GC-MS)technology to analyze gas component,and single electrode plate storage method to evaluate the gas source,which systematically investigates the high-temperature storage gas under different SOCs condition,especially 100％SOC and 0％SOC,and the cycle gas of commercial soft park lithium ion batteries.The results show that the gas volume curve is the shape of the bath in the range of 0～100％SOC.Gas volume is obvious at 100％SOC,continuously increasing with time,and the major reaction productions are CO2 and CO.FEC content and injection coefficient have a significant effect on gas generation.The gas productions are mainly caused by reactions of EC and NCM811,secondarily by FEC and NCM811,Si-C.Gas generation is gentle at 0％SOC,and no change with time after stabilization,mainly CO2,CO,and H2.The gas productions mainly come from the electrolyte and Si-C reaction.The major gas components are CO2,CO,and H2 during high temperature cycle.In addition,the gas generation of battery followed cycle is worsened at high temperature storage;the gas produced at high temperature storage is partly absorbed during the cyclic process.