PVD of Metallic Lithium Layers and Lithiated Silicon Layers for High-Performance Anodes in Lithium Ion Batteries

Because state of the art systems have almost reached their limitation for performance gain, replacing conventional electrode materials is one of the most relevant challenge for next-generation lithium ion batteries. For the anode, promising candidates are lithium or silicon. We demonstrate a physical vapor deposition process for the preparation of pure metallic lithium layers on sheets of copper or stainless steel and as well on copper foils in the layer thickness range of 1-20 µm. The lithium layers have been deposited by thermal evaporation at static coating rates up to 120 nm/s and dynamic deposition rates up to 1 µm·m/min, respectively. Furthermore, the deposition of lithiated silicon layers with various compositions has been performed by coevaporation of lithium and silicon, where silicon was evaporated by a deflected electron beam. By upgrading the vacuum tool with a glovebox enclosing the load lock and with a specialized feeding system for the evaporation feedstock, a consequent material handling under inert argon atmosphere could be realized.