Highly\nEffective Polyacrylonitrile-Rich Artificial\nSolid-Electrolyte-Interphase for Dendrite-Free Li-Metal/Solid-State\nBattery

Lithium\nmetal anode batteries have attracted significant attention\nas a promising energy storage technology, offering a high theoretical\nspecific capacity and a low electrochemical potential. Utilizing lithium\nmetal as the anode material can substantially increase energy density\ncompared with conventional lithium-ion batteries. However, the practical\napplication of lithium metal anodes has encountered notable challenges,\nprimarily due to the formation of dendritic structures during cycling.\nThese dendrites pose safety risks and degrade battery performance.\nAddressing these challenges necessitates the development of a reliable\nand effective protection layer for lithium metal. This study presents\na cost-effective and convenient method to spontaneously produce lithium\nmetal protective layers by creating polymeric layers by using acrylonitrile\n(AN). This method remarkably extends 6× of the lifetime of lithium\nmetal anodes under high current density (1 mA/cm<sup>2</sup>) cycling\nconditions. While the cycle life of bare lithium metal is approximately\n150 h under high current cycling conditions, AN-treated lithium metal\nanodes exhibit an impressive longevity of over 900 h. The AN-treated\nlithium metal anodes are further integrated and tested with sulfide-based\nLi<sub>10</sub>GeP<sub>2</sub>S<sub>12</sub> (LGPS) solid-state electrolytes\nto evaluate its interfacial stability at a solid–solid interface.\nThe formation of the polyacrylonitrile (PAN)-rich ASEI, due to AN-treatment,\neffectively reduces and stabilizes the cell overpotential to only\none-tenth of that with the interface without treatment. This strategy\npaves a route to enable a highly efficient and highly stable Li/LGPS\nsolid-state battery interface.