Enhancing laser-based contacting of aluminum current collector foils for the production of lithium-ion batteries using a nanosecond pulsed fiber laser

Abstract

Cost reduction is a major aim for innovations in lithium-ion battery production. A promising approach to meet the high economic requirements is using high-speed manufacturing technologies like laser beam welding. This process can be applied to electrically connect the pre-stacked electrode sheets at the uncoated part of the current collectors. However, laser beam welding of the aluminum current collector foils is particularly challenging due to emerging seam defects such as cracks. In order to eliminate cracks occurring between the seam and the base material, this paper presents investigations on joining aluminum foil stacks using a nanosecond pulsed laser. Forty aluminum foils were welded with an arrester tab in a lap joint. This work examined the influence of several process parameters on the seam characteristics. A detachment of the seam from the foils was prevented, and promising results regarding the mechanical and electrical seam properties were achieved.