Homogeneous bottom-growth of lithium metal anode enabled by double-gradient lithiophilic skeleton

A dual-gradient 3D lithiophilic Si@carbon nanofibers @ZnO skeleton is designed to guide the homogeneous bottom-growth of Li metal for safe Li-metal batteries. • Double-gradient lithiophilic 3D skeleton is designed for lithium metal anode. • The 3D porous current collector can reduce overpotential and avoide top-growth of Li. • The top lithiophilic layer shows self-repair function under high capacity Li deposition. • The designed SCZ-Li||LiFePO 4 full cell delivers good cycling stability at 5C. Lithium (Li) metal is considered as the most promising anode material for the next-generation high performance Li batteries. However, the uncontrollable dendritic growth impedes its commercial application. Herein, we design a 3D Si@carbon nanofibers (CNFs) @ZnO-ZnO-Cu skeleton (SCZ) for guiding the homogeneous bottom-growth of Li metal. The top Li x Si@CNFs and bottom Li y Zn@CNFs layers could form conductivity and overpotential gradient to avoid the “top-growth” of Li metal. Moreover, the top lithiophilic Li x Si@CNFs layer could regulate the nucleation and deposition of Li-ions even if the lithium dendrites grow out of the skeleton under high capacity Li deposition (30 mAh cm −2 ). As a result, the SCZ-Li||LiFePO 4 full cell delivers a high capacity of ~104 mAh g −1 (~94.82% capacity retention) after 2000 cycles at 5C, elucidating the potential application of the 3D double-gradient Li metal composite anode.