Cell-Internal Contacting of Prismatic Lithium-Ion Batteries Using Micro-Friction Stir Spot Welding

The reliable production of high-quality lithium-ion battery components still poses a challenge, which must be met to cope with their rising demand. One key step in the production sequence is the process of cell-internal contacting, during which the electrode carrier foils of the anode and the cathode are joined with the arrester. This is usually done with ultrasonic or laser beam welding. Both joining processes, however, show limitations concerning the quality of the weld. This paper presents a new approach for cell-internal contacting by using micro-friction stir spot welding. Welding experiments were conducted in which joints with high mechanical strengths were produced. It was also shown that large stacks with foil numbers of 100 can be joined in only a few tenths of a second. The process is therefore especially of interest for the fast production of large-scale battery cells or other new types of high-energy-dense battery cells.