Decelerating and Accelerating Sulfur Reduction Reaction via P‐OV‐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 (S 8 ) to liquid (soluble Li 2 S n (4≤n≤8)) is relatively easy due to the low activation energy, whereas the subsequent conversion of liquid (soluble Li 2 S n ) to solid (insoluble Li 2 S 2 /Li 2 S) has much higher activation energy, which leads to the accumulation of Li 2 S n and exacerbates the shuttle effect of Li 2 S n . 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, In 2 O 3 nanospheres containing phosphorus doping and oxygen vacancies (P‐O V ‐In 2 O 3 NSs) are designed and synthesized as a selective catalyst for Li‐S batteries. Contributed by the unique selective catalytic capability, the batteries using P‐O V ‐In 2 O 3 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.