InOOH as an efficient bidirectional catalyst for accelerated polysulfides conversion to enable high-performance lithium–sulfur batteries

Lithium–sulfur (Li–S) batteries with the prominent advantages are greatly expected to be the attractive alternatives in the next-generation energy-storage systems. However, the practical success of Li–S batteries suffers from the shuttle effect and depressed redox kinetics of polysulfides. Herein, for the first time, InOOH nanoparticles are employed as a potent catalytic additive in sulfur electrode to overcome these issues. As demonstrated by the theoretical and experimental results, the strong interactions between the InOOH nanoparticles and sulfur species enable the effective adsorption of polysulfides. More significantly, InOOH nanoparticles not only effectively expedite the reduction of sulfur during the discharge process, but also dramatically accelerate the oxidation of Li₂S during the charge process, presenting the marvelous bidirectional catalytic effects. Benefited from these distinctive superiorities, the cells with InOOH nanoparticles harvest an excellent capacity retention of 69.5% over 500 cycles at 2C and a commendable discharge capacity of 891 mAh g⁻¹ under a high-sulfur loading of 5.0 mg cm⁻². The detailed investigations in this work provide a novel insight to ameliorate the Li–S electrochemistry by the bidirectional catalyst for high-performance Li–S batteries.