Abstract:

With the rapid development of the new-energy industry and the concept of "integration of source network, charge, and storage", lithium-ion batteries have been widely used for energy storage. To control the group cost, the battery modules applied in the field of energy storage are developing towards high voltage and large capacity, which puts forward higher requirements for the grouping technique of lithium-ion batteries, especially for soft-pack batteries. In this paper, based on the theoretical calculation and finite element analysis method, the expansion force analysis of the soft package large module for energy storage is carried out to investigate the structural stability of the module in the whole life cycle. The results show that the selection of foam, the material of the end plates, and the number and strength of the fixing bolts used for the end plates are important factors in the design process of the large soft pack module for energy storage. A supreme design scheme can effectively reduce or even avoid the influence of the battery expansion force on module structures, improve the structural stability of the module, and produce modules with better safety and longer service life.

Key words: energy storage, soft pack battery, battery module, stability, expansibility force