Catalytic Interfaces-Enriched Hybrid Hollow Spheres Sulfur Host for Advanced Li-S Batteries

Lithium-sulfur (Li-S) batteries are considered as a promising next-generation energy storage technology due to its high energy density over 2500 Wh kg(-1) and low cost. Its development and application require to overcome several obstacles including the large volume change, the low electrical conductivity of S/Li2S, and the shuttle effect of lithium polysulfides (LIPSs). In this work, the hollow N-doped carbon spheres (NHCS) decorated with nanosized SnS2 (NHCS-SnS2) are synthesized and investigated to host sulfur used as the cathode for Li-S batteries. Highly conductive NHCS offer a large specific surface area and robust confinement for active material S, while SnS2 nanoparticles provide efficient chemisorption of LIPSs and promote the deposition of solid Li2S. The NHCS-SnS2/S cathode materials deliver a high discharge capacity 1344 mAh g(-1) at 0.2 C and a low capacity decay over 200 cycles at 0.5 C. The outstanding cycling stability at 0.2 C with high sulfur loading of 3.0-3.1 mg cm(-2) can also be readily attained. The excellent electrochemical performance is attributed to possible triple phase catalytic effect of NHCS-SnS2 and electrolyte, and such structure permits the full utilization of active materials from S-8 to Li2S.