High-density oxygen-doped nano-TaN enables robust polysulfide interconversion in Li−S batteries

To tackle undesirable shuttle reaction and sluggish reaction kinetics in lithium–sulfur (Li–S) batteries, we develop a porous and high-density oxygen-doped tantalum nitride nanostructure (nano-TaNO) as an efficient catalyst through delicate tailoring. Benefiting from well-defined interior and surface nanopore channels, the nano-TaNO favors abundant sulfur storage, easy electrolyte infiltration and good electrons/Li+ transport. More importantly, high-density O dopant in nano-TaNO not only provides high conductivity, but also promotes polysulfide adsorption/conversion via Li–O chemical interactions and the generation of S3*− radicals to activate additional evolution path from S8 to Li2S. Consequently, the nano-TaNO-based cathode exhibits excellent specific capacity and cyclability even under high sulfur loading condition. These interesting findings suggest the great potential of tantalum nitride and a high amount of anion doping engineering in manipulating intermediates and building high-performance Li−S rechargeable batteries.