Potentials of Magnetron Sputtering for Battery Applications—A Case Study for Thin Lithium Metal Anodes

Due to its very high theoretical specific capacity, lithium is still considered a promising anode material for innovative next-generation battery cells. The aim is to produce thin lithium metal anodes (LMAs) that are sufficient for the battery cell due to the lithium already present in the cathode and thus additionally increase the energy density of the cell. The production of thin lithium layers (<10 µm) is challenging with most processes, and very costly with decreasing thickness. In this study, the use of magnetron sputtering to deposit thin layers of lithium for the production of LMAs is tested. An innovative process—the deposition of lithium from a liquid phase via Hot Target Sputtering—will be presented that has the potential to overcome the previous limitations in the deposition rate, and enables the potential for industrial application. The process was successfully tested in terms of general process control, stability and reproducibility and used to produce lithium metal anodes. These were then successfully integrated in All-Solid-State-Battery (ASSB) cells and compared with a lithium reference foil in a C-rate test with regard to their electrochemical performance reaching ≈ 110 mAh g−1 at a 1C discharge rate.