Analysis of wrinkles and corrugations in the electrode calendering process

Abstract

Calendering is a crucial process in manufacturing of lithium-ion batteries electrodes. Wrinkles and corrugations are the main manufacturing defects in the calendering process. This study aims at studying the formation mechanism of wrinkles and corrugations. Corrugations and wrinkles of the electrodes were revealed to be more dependent on the difference between the front and back tensions. The tortuosity of corrugations was reduced by 34.2% when the tension difference decreased from 20 to 5 N. The increase in the tension difference led to a linear increase of the shear displacement δ, causing severe wrinkles in the uncoated area of the electrodes. The analytical prediction model for wrinkles during calendering was established based on the shearing of a rectangular membrane. The optimal web tension conditions, at a tension difference of 17 N, was achieved to obtain the optimal calendered electrodes.