Processing of advanced battery materials—laser cutting of pure lithium metal foils

Abstract

Due to the increasing demand for high-performance cells for mobile applications, the standards of the performance of active materials and the efficiency of cell production strategies are rising. One promising cell technology to fulfill the increasing requirements for actual and future applications are all solid-state batteries with pure lithium metal on the anode side. The outstanding electrochemical material advantages of lithium, with its high theoretical capacity of 3860 mAh/g and low density of 0.534 g/cm3, can only be taken advantage of in all solid-state batteries, since, in conventional liquid electrochemical systems, the lithium dissolves with each discharging cycle. Apart from the current low stability of all solid-state separators, challenges lie in the general processing, as well as the handling and separation, of lithium metal foils. Unfortunately, lithium metal anodes cannot be separated by conventional die cutting processes in large quantities. Due to its adhesive properties and toughness, mechanical cutting tools require intensive cleaning after each cut. The presented experiments show that remote laser cutting, as a contactless and wear-free method, has the potential to separate anodes in large numbers with high-quality cutting edges.