锂离子电池寿命衰减机理及改善途径

With the increasing demand for energy storage，higher requirements have been put forward for the cycle life，capacity，working stability，and rate performances in batteries. Lithium-ion batteries（LIBs）are favoured for their excellent electrochemical performance and broad development prospects and have been widely applied in mobile devices，electric vehicles，and other fields. However，the bottleneck factors such as life decay and high cost have hindered the further promotion and application of LIBs. This article reviews the main factors affecting the cycle life decay of LIBs，including damage and gas production of positive electrode materials，as well as the consumption of active lithium caused by the repair of negative electrode solid electrolyte interface（SEI）membrane and the formation of lithium dendrites. Effective ways for scientific researchers to improve the life properties of LIBs in recent years，including the structural design of negative electrode materials and the control of SEI film stability，as well as ion doping and surface coating of positive electrode materials，are also summarized. Finally，the future development trends in this field from three aspects，such as multi-element doping，uniform coating new technology，and stable SEI film control are proposed based on the bottleneck issues in the development of lithium-ion batteries.