Exceptional adsorption and catalysis effects of hollow polyhedra/carbon nanotube confined CoP nanoparticles superstructures for enhanced lithium-sulfur batteries

Lithium-sulfur (Li-S) batteries with high theoretical energy density are promising next-generation green energy storage devices. However, the severe shuffling and depressed conversion of lithium polysulfides in sulfur cathode are two pivotal factors that limit the practical application of Li-S batteries. To solve these issues, rationally designed hollow polyhedra/carbon nanotube confined CoP nanoparticles superstructures (CoP@HPCN) for enhanced Li-S batteries are proposed here. With the high porosity and cavity, and multidirectional channels, hollow polyhedra/carbon nanotube architecture can effectively accommodate volume expansion and entrap sulfur species. More importantly, the experimental and theoretical results indicate that the uniformly inserted polar CoP nanoparticles as electrocatalyst not only significantly anchor polysulfides, but also catalyze the transformation of lithium polysulfides. Benefiting from these advantages, the CoP@HPCN based sulfur cathode can achieve good rate performance, impressive cycling stability, and ultralow self-discharge constant of 0.03% per day after resting for 60 days even at high sulfur loading of 3.7 mg cm(-2). This work synergistically combines desired design and electrocatalysis in sulfur electrode and sheds some light on the construction of advanced Li-S batteries.