Amorphous High‐Entropy Alloy Interphase for Stable Lithium Metal Batteries

The unstable anode/electrolyte interphase induces severe lithium dendrite growth hindering the practical application of lithium metal batteries. The lithium alloy interphase presents a promising strategy for regulating Li+ plating/stripping behavior. However, binary or ternary alloys are insufficient to address various challenges in lithium metal batteries and the high temperature required for alloy preparation hampers their direct applications on lithium metal surfaces. In this study, a high‐entropy alloy (HEA) interphase is developed on lithium metal surfaces via room‐temperature magnetron sputtering, showcasing multifunctional advantages in regulating Li+ plating/stripping behavior. The cocktail effect of the (HEA) facilitated the formation of a homogeneous amorphous interphase with abundant lithiophilic sites and magnetic properties, promoting uniform Li+ nucleation and deposition. Furthermore, the high mechanical strength and corrosion resistance of HEA provided physicochemical stability for the lithium anode interphase, consistently suppressing dendrite growth. Consequently, lithium metal anodes with HEA interphases exhibited robust cycling performance lasting over 4000 h at 2 mA cm−2. The LFP full battery demonstrated high‐capacity retention of 90% with an average Coulombic efficiency of 99.7%. Thus, the HEA interphases on lithium metal surfaces offer controllable regulation of Li+ deposition behavior through high‐entropy manipulation, opening novel strategies for stable lithium metal batteries. Lithium dendrites hinder the practical use of lithium metal batteries. Traditional alloy interphases are inadequate and require high temperatures. This study introduces a high‐entropy alloy interphase via room‐temperature magnetron sputtering, promoting uniform Li+ nucleation and deposition. The high‐entropy interphase with abundant lithiophilic sites and magnetic properties offers high mechanical strength and corrosion resistance, ensuring robust cycling performance for 4000 h.