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-Co 3 S 4 heterostructure sulfur cathode substrate made up of numerous tiny needle-like structures is created. The benefits of CoP with outstanding conductivity and Co 3 S 4 with great adsorption capacity are combined in the as-prepared CoP-Co 3 S 4 heterostructures, which achieve efficient capture-diffusion-transformation of polysulfides at the interface. The CoP accelerates the redox kinetics toward polysulfide conversion, and the Co 3 S 4 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 Co 3 S 4 surface to the CoP surface. As a result, the CoP-Co 3 S 4 @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.