Stabilizing the interface of PEO solid electrolyte to lithium metal anode via a g-C 3 N 4 mediator.

g-C 3 N 4 is introduced to the PEO electrolyte as a mediator to stabilize the interface to lithium metal anode. As a result, the interface resistance is stabilized after cycling and the symmetric cell exhibits a cycle life over 900 h, indicating that the interface stability is evidently promoted.