Enhancing the polysulfide redox conversion by a heterogeneous CoP-Co3S4 electrocatalyst for Li-S batteries

The development of lithium-sulfur (Li-S) batteries necessitates the creation of efficient cathode materials. By simultaneous phosphating and sulfurating, a spindle-shaped CoP-Co3S4 heterostructure sulfur cathode substrate made up of numerous tiny needle-like structures is created. The benefits of CoP with outstanding conductivity and Co3S4 with great adsorption capacity are combined in the as-prepared CoP-Co3S4 heterostructures, which achieve efficient capture-diffusion-transformation of polysulfides at the interface. The CoP accelerates the redox kinetics toward polysulfide conversion, and the Co3S4 has a considerable adsorption power toward polysulfides. The quick nucleation of polysulfide and increased capture effectiveness are aided by the quick transfer of polysulfide from the Co3S4 surface to the CoP surface. As a result, the CoP-Co3S4 @S cathode battery with a 1.1 mg cm−2 sulfur load achieves a high initial capacity of 1516.9 mAh g−1 at 0.2 C and maintains that capacity after 100 cycles at 750.1 mAh g−1. After 300 cycles, even the 565.1 mAh g−1 specific capacity can be attained at 1 C.