In order to meet the high energy and long lifespan requirements of electric ve-hicles,designing a safe,reliable,and durable battery system is a necessary condition for ensuring the healthy development of the new energy electric vehicle industry.The expansion force caused by the charging and discharging of lithium-ion batteries not only damages the safety of the battery sys-tem,but also reduces the battery life.In addition,the expansion force will increase with the number of charging and discharging cycles.The changes in cell morphology during charging and discharging processes are studied,as well as the effects of external forces on cell thickness and internal stress throughout the battery package.The experimental results indicate that the dimension and morphology of the battery cell undergo irreversible changes during the charging and discharging process,and the degree of expansion exhibits nonlinear changes with the increase of charging and discharging cycles.In addition,the external force on the cell will also affect its thickness and size,thus further affecting the compression ratio of the aerogel between the cells and the internal stress of the whole package.These research results provide important references for optimizing battery design and improving bat-tery performance.
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维普
