Relationship between the Orientation of the (100) Crystal Plane and Elongation in Ultrathin Electrolytic Copper Foils

Electrolytic copper foils (ECFs), owing to their excellent mechanical properties and conductivity, have become an indispensable component as an anodic current collector in lithium-ion batteries. ECFs often show texture properties, but the intrinsic relationship between the texture and mechanical properties is rarely reported. The authors find a conspicuous preference for the (100) crystal plane in 6 and 8 μm ultrathin ECFs with high elongation. And certain ECFs even exhibit a positive correlation trend between elongation and the (100) relative texture coefficient. It can be inferred that enhancing the (100) texture contributes to the improvement of the elongation in ECFs. Moreover, the Schmid factor values for the (111), (100), and (110) planes are calculated. The results revealed that the number of slip systems that can be activated under different tensile directions of the (100) plane is the largest, while the number of (110) plane is the least. It implies that under equivalent conditions, ECFs with (100) plane orientation are more prone to undergo plastic deformation, thereby facilitating high elongation. In contrast, the (110) plane orientation contributes to a high tensile strength.