Electrode structure, rechargeable battery and method for joining battery tab stack to electrode lead for the same
An electrode structure of rechargeable battery includes a battery tab stack, an electrode lead, a welding protective layer and a welding seam. The battery tab stack is formed by extension of a plurality of electrode sheets. The electrode lead is joined to one side of the battery tab stack. The welding protective layer is joined to another side of the battery tab stack opposite to the electrode lead. The welding seam extends from the welding protective layer to the electrode lead through the battery tab stack.
1 . A method for joining battery tab stack to electrode lead for rechargeable battery, comprising:
providing a multilayer structure comprising a battery tab stack, a welding protective layer and an electrode lead, wherein the welding protective layer and the electrode lead are located at opposite sides of the battery tab stack, respectively;
performing a lamination process, wherein the battery tab stack, the welding protective layer and the electrode lead are laminated; and
performing a laser welding process, wherein a laser is delivered along a direction from the welding protective layer toward the electrode lead to join the battery tab stack to the welding protective layer and the electrode lead;
wherein in the lamination process, a pushing force is exerted onto a first portion of the multilayer structure in a pressing direction, such that the first portion is concave with respect to a second portion of the multilayer structure where the pushing force is not exerted.
2 . The method for joining battery tab stack to electrode lead for rechargeable battery according to claim 1 , wherein the battery tab stack comprises a plurality of tabs, the first portion of the multilayer structure is concave with respect to the second portion by a depth, and the depth is twice a thickness of any one of the plurality of tabs or less.