Fast Li Ion Flux LiF-Rich SEI Inducing Spatially-Confined Deposition for Dendrite-Free Li Metal Anode.

Lithium (Li) metal, with its ultra-high theoretical specific capacity and low redox potential, is a promising anode material, yet uncontrollable dendrite growth limits its practical use. Confining Li deposition from one-dimensional dendritic to three-dimensional spherical growth is an effective solution. Herein, we propose a synergistic strategy catalyzed by Li-Au alloy nucleation sites to generate a LiF-rich solid electrolyte interphase layer. This achieves low Li nucleation potential and high interfacial ion transport kinetics, making Li deposition reaction-controlled (leading to spherical Li) instead of diffusion-controlled processes (leading to dendritic Li). Symmetric cells with the modified Li electrode cycle nearly 7500 h (18,000 cycles) at 10 mA cm-2. LiFePO4 (LFP) full cells retains 80.3% of their initial capacity after 1000 cycles at 2C; LiCoO2 full cells demonstrated a capacity of 153 mAh g-1 at an ultra-high 40C (7.3 mA cm-2) rate. Even at a low N:P ratio of 1.4, the LFP full cell can still be stably cycled for over 200 cycles at 1C (1.8 mA cm-2) while delivering a high capacity of 151.5 mAh g-1. This scalable interfacial design strategy provides important insights for the preparation of dendrite-free Li anodes to improve battery safety.