Abstract: With the rise of the new energy industry, module design with high specific energy, low cost, and high assembly efficiency has become the mainstream trend. However, lithium-ion batteries may experience bulging during the charging and discharging process, which can lead to a decrease in the cycling life of the cells. Moreover, the expansion force from the cell to the module level is increasing, and excessive expansion force can cause damage to the module end and side plates. This article is based on the study of the superposition relationship of the expansion force of the cells, tested single cell, 2P1S, 1P2S, 3P1S, 1P3S, 4P1S, 1P4S, and 3P4S modules, the influence of the series and parallel connection of cells on the expansion force of the module can be ignored. And the expansion force of the module is a logarithmic function of the number of cells. Provide guidance for the design of safety modules by predicting the expansion force of modules in different grouping methods.

Key words: New energy; Module; Expansion force; Superposition relationship

摘要： 随着新能源行业的兴起，高比能、低成本、高成组效率的模组设计已成为主流趋势。 然而锂离子电池在充放电过程中会发生鼓胀，导致电芯循环寿命降低。且电芯到模组级别膨 胀力呈增大趋势，过大的膨胀力会使模组端侧板发生破坏。文章基于电芯膨胀力叠加关系的 研究，分别对单体电芯、2P1S、1P2S、3P1S、1P3S、4P1S、1P4S 以及 3P4S 模组进行了测试， 得出电芯串并联方式对模组膨胀力大小的影响可以忽略不计，且模组膨胀力的大小与电芯的 个数呈对数函数的关系。通过预测不同成组方式模组膨胀力的大小，为安全模组设计提供指 导意义。

关键词: 新能源；模组；膨胀力；叠加关系