Comparison of Different Current Collector Materials for In Situ Lithium Deposition with Slurry-Based Solid Electrolyte Layers

In this paper, we investigate different current collector materials for in situ deposition of lithium using a slurry-based beta-Li3PS4 electrolyte layer with a focus on transferability to industrial production. Therefore, half-cells with different current collector materials (carbon-coated aluminum, stainless steel, aluminum, nickel) are prepared and plating/stripping tests are performed. The results are compared in terms of Coulombic efficiency (CE) and overvoltages. The stainless steel current collector shows the best performance, with a mean efficiency of eta(mean),SST = 98%; the carbon-coated aluminum reaches eta mean,Al+C = 97%. The results for pure aluminum and nickel indicate strong side reactions. In addition, an approach is tested in which a solvate ionic liquid (SIL) is added to the solid electrolyte layer. Compared to the cell setup without SIL, this cannot further increase the CE; however, a significant reduction in overvoltages is achieved.