Cobalt-doped Hollow Carbon Framework as Sulfur Host for the Cathode of Lithium Sulfur Battery

Abstract

Lithium-sulfur batteries are deemed to be the next generation of cost-effective and high energy density systems for energy storage. However, low conductivity of active materials, shuttle effect and sluggish kinetics of redox reaction lead to serious capacity fading and poor rate performance. Herein, a sodium citrate derived three-dimensional hollow carbon framework embedded with cobalt nanoparticles is designed as the host for sulfur cathode. The introduced cobalt nanoparticles can effectively adsorb the polysulfides, enhance the kinetics of conversion reaction and further improve the cyclic and rate performance. The obtained cathode delivered a high initial discharge capacity of 1280 mAh∙g-1 at 0.5C, excellent high-rate performance up to 10C and stable cyclic capacity of 770 mAh∙g-1 at 1C for 200 cycles with high Columbic efficiency.