Sealing life prediction of Li-ion pouch cell under uncertainties using a CZM-based degradation model

Sealing problems cause premature retirement of Lithium-ion pouch cells and potential safety accidents in the service stage. This paper mainly investigates the sealing failure behavior of Li-ion pouch cell. A CZM-based peeling model is established to explain the actual sealing failure behavior of the soft package in the cohesive zone. Based on the peeling model, a degradation model is established to describe the decrease of the debonding strength and feature length in the cohesive zone. It can explain the decrease of the maximum peeling force as the sealing performance degradation indication of Li-ion pouch cell. Then, the reliability function using a stress-strength interference model is built for the sealing life prediction. Meanwhile, the gamma process is utilized to describe the variety of the strength and stress. Finally, experiments and discussion are presented to validate our method. The result shows that our method can provide a significant reference for the sealing life prediction of Li-ion pouch cell working under different variable loads.