An Artificial Protective Coating toward Dendrite‐Free Lithium‐Metal Anodes for Lithium–Sulfur Batteries

Abstract

Metallic lithium (Li) has attracted considerable interest as a high‐capacity anode material for the next‐generation Li‐metal batteries, yet its commercial availability is still challenged by its strong reactivity with electrolyte and uncontrollable growth of Li dendrites. Herein, a tuned Li anode is fabricated through a facile surface modification strategy. The LiF‐dominant artificial coating layer, due to its low surface‐diffusion energy barrier and excellent chemical stability against Li and electrolyte, is efficient in stabilizing the solid‐electrolyte interphase (SEI) and directing homogeneous Li stripping/plating upon repeated cycling. Therefore, it significantly mitigates the corrosion reaction on the anode side and restrains the Li dendrite growth, contributing to suppressed anode degradation. As a result, the tuned Li metal achieves high symmetric cell performance, delivering a substantially decreased voltage overpotential of 37 mV over 3000 h of cycling (>4 months) at high current density (up to 8 mA cm −2 ). Moreover, the assembled high‐loading Li–S pouch cells (200 mg of sulfur) using the tuned Li anode approach a high capacity (up to 189 mA h) together with good electrochemical cyclability. This work presents a viable route to regulate the Li surface chemistry and interface property for dendrite‐free Li‐metal anodes.