In situ fluoro-oxygen codoped graphene layer for high-performance lithium metal anode.

Abstract

Because traditional lithium-ion batteries have been unable to meet the energy density requirements of various emerging fields, lithium-metal batteries (LMBs), known for their high energy density, are considered promising next-generation energy storage batteries. However, a series of problems, including low coulombic efficiency and low safety caused by dendrites, limit the application of lithium metal batteries. Herein, fluoro-oxygen codoped graphene (FGO) was used to modify the copper current collector (FGO@Cu). FGO-coated current collector provides more even nucleation sites to reduce the local effective current density. FGO is partly reduced during cycling and helps form stable LiF-rich SEI. Moreover, graphene's oxygen and fluorine functional groups reconstruct the current density distribution, promoting uniform lithium plating. The FGO@Cu current collector demonstrates superior properties than commercial Cu foil. The FGO@Cu delivers a 97% high CE for over 250 cycles at 1 mA cm-2. The FGO@Cu symmetrical battery cycled at 1 mA cm-2 for over 650 h. LiFePO4 fuel cell with a lithium-plated FGO@Cu collector as an anode exhibits superior cycling stability.