
Thermal Wrinkling: A Hidden Challenge in EV Battery Anode Production and Its Solutions
Thermal Wrinkling: A Hidden Challenge in EV Battery Anode Production and Its Solutions Battery anodes for electric vehicles (EVs) are typically mass-produced using the Roll-to-Roll (R2R) process. However, an unexpected and significant hurdle in this continuous manufacturing method is “thermal wrinkling.” Thermal wrinkling refers to the permanent folds that occur in electrode sheets due to thermal-induced deformation, which does not revert upon cooling. Recent research has highlighted this issue, analyzing its root causes and proposing effective mitigation strategies. When Does Thermal Wrinkling Occur? Thermal wrinkling primarily occurs in drying ovens when electrode sheets experience rapid or uneven heating. Differential thermal expansion between the copper current collector foil and the coating layer destabilizes web tension, causing irreversible wrinkling and plastic deformation. Specifically, during the drying stage of the R2R process, high and inconsistent oven temperatures cause uneven thermal expansion rates between layers. This differential expansion generates uneven mechanical stresses across the