A mechanistic modeling method for limited overcharge abuse of lithium-ion batteries

Exploring the electrochemical-thermal coupling failure mechanism during limited overcharge abuse is essential to improving the safety performance of lithium-ion batteries (LIBs). However, existing overcharging studies mainly focus on thermal runaway (TR), not revealing electrochemical reactions or thermal effects in the limited overcharge stage before TR and their resulting failure mechanisms. Therefore, a mechanistic modeling method for limited overcharge abuse of LIBs is proposed. Specifically, in the limited overcharge stage, the model considers transition metal ion dissolution and electrolyte oxidation effects on battery conductivity, along with lithium deposition's impact on film resistance and heat generation. In the post-overcharge damage stage, it accounts for lithium dissolution's influence on film resistance. This enables the model to accurately simulate voltage and temperature responses under limited overcharge abuse. Compared with the traditional electrochemical-thermal coupling model, the mean square error (MSE) of voltage in the limited overcharge stage and the post-overcharge damage stage are reduced by 79.31 % and 91.40 %, respectively. This paper provides a new theoretical framework for the mechanistic analysis of the limited overcharge abuse behavior of LIBs. The proposed model can assess the degree of battery damage and provide critical data support to optimize the battery management systems (BMS) warning strategy.