Antimony‐Doped Lithium Phosphate Artificial Solid Electrolyte Interphase for Dendrite‐Free Lithium‐Metal Batteries

Abstract Metallic lithium (Li) is a promising anode for Li‐based batteries, owing to its high theoretical capacity and the low potential. However, the dendrites and high chemical activity of metallic Li limits its practical applications. To overcome these challenges, a fast‐ionic conductor, antimony‐doped lithium phosphate (Sb‐doped Li 3 PO 4 ) artificial solid electrolyte interphase (SEI) layer, is directly coated on bare copper (Cu) foil by radio frequency (RF) magnetron sputtering, which can facilitate the uniform distribution of lithium ions, reduce the side reaction, and even inhibit the dendrite growth. As a result, the artificial Sb‐doped Li 3 PO 4 SEI‐modified Cu electrode renders a good coulombic efficiency of 97 % for approximately 285 cycles at current density of 1 mA/cm 2 and over 700 h of stable cycles in a symmetric cell. The fabricated artificial SEI layers make the deposition of lithium occur more densely and the electrochemical impedance is smaller compared to the bare Cu electrode. This study will impact the general approach to realize and achieve next‐generation high‐energy‐density lithium‐metal batteries.