Oxygen‐Vacancy‐Rich Interlayers Trigger Lithium Metal Anodes With Extended Cycling Life

ABSTRACT

Lithium metal anodes hold great promise for next‐generation high‐energy‐density batteries owing to their ultrahigh capacity and low electrochemical potential, yet their deployment is plagued by dendritic growth and unstable SEI. Herein, we construct an oxygen‐vacancy‐rich interlayer, consisting of antimony tin oxide (ATO) at the top surface and Li─Sn/Li─Sb/Li ₂ O phases at the bottom surface, on the lithium anode by coating plasma treated ATO. With unreacted ATO providing rich oxygen vacancies at the top surface, the interlayers can facilitate lithium‐salt dissociation and accelerate anion decomposition at the initial cycle, yielding robust LiF‐rich SEI layers. Subsequently, the progressive lithiation of the remaining ATO results in the formation of Li ₂₂ Sn ₅ , Li ₃ Sb, and Li ₂ O phases. These phases act as a lithophilic interlayer, which homogenizes lithium nucleation and reduces nucleation overpotential during cycling. Benefiting from the hybrid interface design, Li@ATO symmetric cells stably operate for over 3000 h at 3 mA cm ⁻² and 3 mAh cm ⁻² , and a 400 Wh/kg Li@ATO‖NCM811 pouch cell cycles more than 130 cycles. This work highlights oxygen‐vacancy engineering as a key strategy to simultaneously regulate the SEI components, providing a new pathway toward practical high‐energy‐density lithium metal batteries.