Engineering Oxygen Vacancies in In₂O₃ with Enhanced Polysulfides Immobilization and Selective Catalytic Capability

Lithium-sulfur (Li-S) battery is identified as an ideal candidate for next-generation energy storage systems in consideration of its high theoretical energy density and abundant sulfur resources. However, the shuttling behavior of soluble polysulfides (LiPSs) and their sluggish reaction kinetics severely limit the practical application of the current Li-S battery. In this work, a series of In₂O₃ nanocubes with different oxygen vacancy concentrations are designed and prepared via a facile self-template method. The introduced oxygen vacancy on In₂O₃ can effectively rearrange the charge distribution and enhance sulfiphilic property. Moreover, the In₂O₃ with high oxygen vacancy concentration (H-In₂O₃) can slightly slow down the solid-liquid conversion process and significantly accelerate the liquid-solid conversion process, thus reducing the accumulation of LiPSs in electrolyte and inhibiting the shuttle effect. Contributed by the unique selective catalytic capability, the prepared H-In₂O₃ exhibits excellent electrochemical performance when used as sulfur host. For instance, a high reversible capacity of 609 mAh g^-1 is obtained with only 0.044% capacity decay per cycle over 1000 cycles at 1.0 C. This work presents a typical example for designing advanced sulfur hosts, which is crucial for the commercialization of Li-S battery.