Mechanical Analysis and Strength Checking of Current Collector Failure in the Winding Process of Lithium-Ion Batteries

The current collector fracture failure of lithium-ion batteries (LIBs) occurs during its winding production process frequently, and the consequent damages are usually large, but little research has been conducted on this phenomenon. This work stems from the difficulty and obstacles in the winding process of actual production of LIBs. The fracture failure of the current collectors is easily caused by the evolution and mutation of the mechanical behavior during the winding process, resulting in safety hazards and poor efficiency. The purpose of this work is to reveal the evolution and distribution mechanism of circumferential strain of the current collectors on the fracture failure under the constraint of winding process. Experimental tests, finite element calculations and theoretical model are used to study the evolution and distribution of circumferential strain. The dynamic evolution process of circumferential strain is tested accurately, and the mechanism of fracture failure of current collectors is revealed. The criterion for current collector strength is proposed based on the results of strain analysis and SEM observation.