Improving the Cycling Stability of Li Anode in All-Solid-State Lithium Batteries with Li–Ga Anodic Interlayer

The commercialization of Li metal anodes in all-solid-state lithium batteries (ASSLBs) is hindered by uncontrollable dendritic growth and nonuniform deposition during cycling. Here, we report a facile metal displacement strategy to construct a Li–Ga alloy anodic interlayer to suppress Li dendrite growth and stabilize the anode–solid-state electrolyte interface. The significantly enhanced performance originates from the dramatically improved Li diffusion kinetics, with the Li–Ga alloy modified Li (Li-Ga@Li) anode exhibiting a Li atomic diffusion coefficient twice as high as that of pristine Li metal. Consequently, the Li-Ga@Li|LPSCl|Li-Ga@Li symmetric cells deliver stable lithium stripping/plating behavior over 800 h with minimal polarization and a significantly increased critical current density. When paired with a high-loading LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode active material, Li-Ga@Li|LPSCl|NCM811 ASSLBs demonstrate enhanced rate capability and prolonged cycling stability. This work provides a practical interfacial engineering strategy through diffusivity improvement toward high-performance ASSLBs.