CoS2/carbon hollow sphere was used as a matrix of the sulfur cathode for lithium-sulfur batteries with enhanced rate and cycling performance

CoS2 nanoparticles embedded in carbon hollow spheres (CoS2/C-HS) were prepared by a facile in situ sulfidation and carbonization. When used as the sulfur matrix in the cathode, the CoS2/C-HS can provide a large internal cavity to contain sulfur and accommodate the volume expansion of sulfur, improve the electrical conductivity of the sulfur cathode, as well as limit the dissolution of polysulfide into the electrolyte. The CoS2 nanoparticles can expedite the conversion of polysulfides, capture polysulfides and reduce the loss of active materials through chemical adsorption. The prepared CoS2/C-HS@S cathode materials show an initial discharge capacity of 1115.4 mAh g(-1) and maintained 476.1 mAh g(-1) after 500 cycles at 0.2 C. The high stability is mainly attributed to the synergistic effect of carbon hollow spheres and CoS2 nanoparticles.