Group margin design method and battery

Abstract

The invention provides a group margin design method and a battery. The group margin design method comprises the following steps: providing a battery monomer, wherein the battery monomer comprises a positive plate and a negative plate; performing cycle test on the battery monomers to obtain a positive electrode rebound rate, a negative electrode rebound rate, a first rebound rate and a second rebound rate; acquiring a gap design value based on the first rebound rate and the second rebound rate; obtaining the internal thickness of the battery based on the positive electrode rebound rate and the negative electrode rebound rate; obtaining the battery inner cavity thickness of the battery monomer; and based on the gap design value, the internal thickness of the battery and the internal thickness of the battery, acquiring a group margin which is equal to (the internal thickness of the battery + the gap design value) / the internal thickness of the battery. According to the group margin design method, different factors of expansion of the battery monomers in different health states are considered at the same time, so that the expansion force of the battery monomers in the charge-discharge cycle process is reduced, and the cycle performance and the safety performance of the battery monomers are improved.

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