Coupling A Three-Dimensional Nanopillar And Robust Film To Guide Li-Ion Flux For Dendrite-Free Lithium Metal Anodes

Lithium metal batteries with high theoretical capacity critically suffer from low cycling stability and safety issues mostly due to lithium dendrites. Regulating the Li-ion conduction and Li deposition is essential to achieve dendritic-free Li metal anodes. Herein, a synergistic strategy that combines a 3D nanocopper layer and a robust polymer protective layer is proposed. The 3D nanocopper layer in situ formed on the Li surface could achieve a uniform electric field distribution and contribute to reducing the nucleation barrier for Li deposition and refining the grain size of Li crystallites. Meanwhile, the Li- Nafion film with high Li- ion conductivity and good flexibility was used as a protective layer to provide homogeneous ion distribution and adapt to the volume change during the Li deposition. Consequently, the NCuLi parallel to LiCoO2 full cells exhibited outstanding cycling stability (a capacity retention of 90% over 500 cycles). Our results indicate that the synergistic control of Li-ion conduction and Li deposition is a promising method to achieve dendritic-free Li metal anodes.