Low-pressure cycling of lithium metal anodes with argyrodite solid-state electrolytes enabled by an Sb-based interfacial layer

This study presents a facile and scalable methodology to achieve stable cycling of lithium metal anodes in argyrodite-type Li₆PS₅Cl (LPSCl)-based solid-state batteries using a thermally evaporated antimony (Sb) interlayer. Interfacial analysis of the Sb-coated LPSCl|Li interface revealed its layered structure, featuring a Li₃Sb alloy layer adjacent to the lithium metal, which suppresses void formation and defocuses interfacial current density during Li stripping, thereby enabling dendrite-free cycling under low stack pressures (< 2 MPa). Symmetric Li|Sb-coated LPSCl|Li cells exhibited a critical current density of 2.75 mA cm^-2 and stable operation for over 700 h at 0.75 mA cm^-2. In full cells employing LiNi_0.8Mn_0.1Co_0.1O₂ cathodes, Sb-coated LPSCl afforded stable cycling with an areal capacity of ∼1.25 mAh cm^-2 for 450 cycles without void formation.