Construction of LiCl/LiF/LiZn hybrid SEI interface achieving high-performance sulfide-based all-solid-state lithium metal batteries

Sulfide-based all-solid-state lithium metal batteries (ASSLMBs) have received extensive attention due to their high energy density and high safety, while the poor interface stability between sulfide electrolyte and lithium metal anode limits their development. Hence, a hybrid SEI (LICl/LiF/LiZn) was constructed at the interface between Li_5.5PS_4.5Cl_1.5 sulfide electrolyte and lithium metal. The LiCl and LiF interface phases with high interface energy effectively induce the uniform deposition of Li⁺ and reduce the overpotential of Li⁺ deposition, while the LiZn alloy interface phase accelerates the diffusion of lithium ions. The synergistic effect of the above functional interface phases inhibits the growth of lithium dendrites and stabilizes the interface between the sulfide electrolyte and lithium metal. The hybrid SEI strategy exhibits excellent electrochemical performance on symmetric batteries and all-solid-state batteries. The symmetrical cell exhibits stable cycling performance over long duration over 500 h at 1.0 mA cm⁻². Moreover, the LiNbO₃@NCM712/Li_5.5PS_4.5Cl_1.5/Li-10%ZnF₂ battery exhibits excellent cycle stability at a high rate of 0.5 C, with a capacity retention rate of 76.4% after 350 cycles.