Cathode Cushioning Section for High-Rolling Electrode Integrity

The cathode collector is divided into three distinct sections along the longitudinal direction: a coating section with uniform cathode mixture layer, a non-coating section without cathode mixture layer, and a cushioning section with gradually decreasing cathode mixture layer thickness. This segmentation allows each section to have different mechanical properties, with the cushioning section specifically designed to reduce elongation difference between the coating and non-coating sections during rolling, thereby preventing wrinkles and fractures while maintaining high energy density

The cushioning section is designed with locally varying cathode mixture layer thickness that gradually decreases from the coating section toward the non-coating section. This local quality variation creates a gradient structure that smoothly transitions the mechanical properties between sections, reducing stress concentration and elongation difference at the transition zones during the rolling process

The cathode mixture layer is applied with a pre-designed thickness gradient in the cushioning section before the rolling process begins. This preliminary action creates a built-in compensation mechanism where the varying thickness of the cathode mixture layer pre-adjusts the elongation characteristics of different sections during rolling, eliminating the need for post-application IHA heating and avoiding excessive softening of the collector

The invention replaces the thermal field approach (IHA heating) with a structural field approach (cathode mixture layer thickness gradient). Instead of using heat to modify the mechanical properties of the non-coating section, the cushioning section uses the varying thickness of the cathode mixture layer to mechanically compensate for elongation differences during rolling, achieving the same effect without thermal intervention