新能源锂离子电池热失控性能研究OA

Driven by the"dual carbon"goals,lithium batteries are more widely used in energy storage power stations,electric power,new energy vehicles,and other fields.However,their inherent risk of thermal runaway poses a serious threat to equipment and personal safety.Therefore,the research on the safety characteristics of lithium batteries,especially thermal runaway,holds significant theoretical and practical value.This study focuses on ternary cylindrical lithium-ion batteries(cathode material:LiNi6Co2Mn2O2,anode:graphite).Utilizing characterization methods such as charge-discharge equipment,electrochemical impedance spectroscopy,pulse power,and adiabatic runaway,it was conducted research on the basic electrochemical performance and the risk of adiabatic thermal runaway.It was investigated the basic electrochemical performance of lithium batteries at different states of life and clarified the pattern of adiabatic thermal runaway at different states of charge.The results indicate that after charge-discharge cycling,the external manifestation of lithium-ion batteries is a decrease in effective output capacity,while internally,there is an increase in electrode side reactions,gradual polarization,and a gradual decrease in ion conduction efficiency of the lithium-ion battery,leading to an increase in internal resistance and a decrease in self-stability.It reveals that the impedance of lithium-ion batteries increases with the number of charge-discharge cycles,especially the charge transfer impedance,which significantly increases and leads to increased battery polarization,but it tends to level off after increasing to a certain value.It also clarifies that the risk of thermal runaway in lithium-ion batteries increases with the increase in state of charge.Finally,several suggestions are provided for the use and transportation of lithium-ion batteries.