A single-material battery is prepared using Li10GeP2S12 as the electrolyte, anode, and cathode, based on the Li-S and Ge-S components in Li10GeP2S12 acting as the active centers for its cathode and anode performance, respectively. The single-Li10GeP2S12 battery exhibits a remarkably low interfacial resistance due to the improvement of interfacial contact and interactions, and the suppression of interfacial strain/stress.