Decelerating and Accelerating Sulfur Reduction Reaction via P‐O_V‐In₂O₃ Enables High‐Performance Li‐S Batteries

Abstract

The sluggish sulfur reduction reaction (SRR) kinetics of lithium‐sulfur (Li‐S) batteries seriously limits the development of Li‐S batteries. The initial reduction of solid (S8) to liquid (soluble Li2Sn (4≤n≤8)) is relatively easy due to the low activation energy, whereas the subsequent conversion of liquid (soluble Li2Sn) to solid (insoluble Li2S2/Li2S) has much higher activation energy, which leads to the accumulation of Li2Sn and exacerbates the shuttle effect of Li2Sn. Therefore, establishing one selective catalyst that decelerates the previous solid‐liquid reaction and accelerates the subsequent liquid‐solid reaction is essential for rational tailoring of the SRR for improved performance of Li‐S batteries, but it represents a daunting challenge. Here, considering that the indium oxide catalyst possesses selective catalytic properties and drawing inspiration from the theoretical calculations, In2O3 nanospheres containing phosphorus doping and oxygen vacancies (P‐OV‐In2O3 NSs) are designed and synthesized as a selective catalyst for Li‐S batteries. Contributed by the unique selective catalytic capability, the batteries using P‐OV‐In2O3 NSs modified separators exhibit excellent sulfur utilization, superb rate performance (656 mAh g−1 at 5.0 C), and low‐capacity decay rate of about 0.069% per cycle over 500 cycles at 1.0 C.