Surface Engineered Li Metal Anode for All‐Solid‐State Lithium Metal Batteries with High Capacity

Abstract Lithium metal is being hailed as the holy grail of next‐generation high‐energy‐density all‐solid‐state batteries. However, the poor interfacial compatibility between Li and solid electrolyte and formation of lithium dendrite strongly impedes its practical application. Herein, a facile surface modification strategy is proposed to reconstruct the Li/Li 10 GeP 2 S 12 interface in order to address these problems. Beneficial from amorphous Li 3 PO 4 by radio frequency magnetron sputtering on Li, parasitic side reactions between Li and Li 10 GeP 2 S 12 is strongly suppressed, resulting in a stable cycling performance in symmetric Li/Li cell with a low polarization voltage (about ±180 mV) up to 1000 hours. Moreover, the Li/Li 10 GeP 2 S 12 /LiCoO 2 cell displays a reversible discharge capacity of 104.5 mA h/g at 0.1 C after 50 cycles. It indicates that Li 3 PO 4 layer is not only favorable to improve interfacial stability between Li/Li 10 GeP 2 S 12 but also advantageous to homogenize Li deposition.