Uniformizing the lithium deposition by gradient lithiophilicity and conductivity for stable lithium-metal batteries

The practical application of lithium metal batteries is hindered by the poor reversibility and large volume change caused by the uncontrollable dendritic growth and the highly reactive surface. In this work, favorable Li deposition is achieved by generating gradient lithiophilicity and conductivity in an Ag-decorated graphene/holey graphene film (G-HGA). Dendrite-free Li metal is deposited on the G-HGA matrix, which greatly reduces the surface area and suppresses the side reaction between the electrolyte and the dendritic Li. The average Li-metal plating-stripping coulombic efficiency (CE) on the G-HGA matrix maintains similar to 98.7% over 350 cycles, compared to a worse average CE (similar to 97.3%) with the bare Cu matrix, only for less than 100 cycles. A full cell constructed by using LiFePO4 and prelithiated G-HGA exhibits excellent rate capability and a high capacity retention of 99.6% for 175 cycles at a low negative to positive capacity ratio of 1.13. This advanced design can inspire further development of high-energy and long-lived Li-metal batteries.

Automated summary

In this work, favorable Li deposition is achieved by generating gradient lithiophilicity and conductivity in an Ag-decorated graphene/holey graphene film (G-HGA). The dendrite-free Li metal is deposited on the G-HGA matrix, greatly reducing the surface area and suppressing the side reaction between the electrolyte and dendritic Li. The advanced design, using prelithiated G-HGA and LiFePO4, exhibits excellent rate capability and high capacity retention, showing potential for further development of high-energy and long-lived Li-metal batteries.