WO2 nanoparticle anchored hollow carbon spheres enhanced performance of lithium-sulfur battery

Abstract

Lithium–sulfur battery has drawn considerable attention because of its high theoretical capacity and density, but poor electrical conductivity, volume expansion, and slow redox reactions in lithium–sulfur batteries limit their commercial applications. Hollow carbon nanospheres (HCN) loaded with tungsten dioxide (WO2) nanoparticles were prepared using polystyrene spheres as templates via in situ polymerization, heat treatment, soaking, and high-temperature decomposition reduction. The composites possessed a hollow spherical structure, which can alleviate the volume change of sulfur and anchored the polysulfides. The anchored WO2 nanoparticles with abundant oxygen vacancies can generate many active sites and accelerate the electrochemical reaction kinetics. Therefore, the WO2/HCN/S cathode exhibited 593.5 mAh g−1 over 300 cycles at 1.0 A g−1 with a capacity decay rate of 0.15 % per cycle. This study provides a feasible solution for fabricating high performance cathode for lithium-sulfur battery.