Enhancing utilization of lithium metal electrodes in all-solid-state batteries by interface modification with gold thin films

To evaluate ideal interfaces between Li metal and Li2S-P2S5 solid electrolytes, bulk-type cells were fabricated using thin Li metal films prepared by vacuum-evaporation. The symmetric cell of Li/75Li2S·25P2S5/Li showed a high utilization of Li metal (about 40%), though abrupt decrease of the utilization was observed after 5 cycles. A high utilization of Li metal (about 25%) was retained for 5 cycles by inserting Au thin films at the interface between Li metal and Li2S-P2S5 solid electrolytes. Morphology of Li metal after dissolution/deposition cycles for the cell with Au thin films became more uniform compared to the cell without Au thin films.