Facile synthesis of MOF-derived Co0.85Se in 3D carbon sheets as multifunctional regulators for high-performance lithium-sulfur batteries

Abstract

Lithium-sulfur battery is regarded as a promising candidate for next-generation high-energy storage system, but the lithium polysulfides (LiPSs) shuttling effect and their hysteretic redox kinetics severely impede its commercial viability. To address these puzzles, a well-designed hybrid with 3D carbon sheets grafted with MOFs-derived Co0.85Se nanoparticles is synthesized via a facile strategy and acted as multifunctional regulators for LiPSs. Relying on the coordination of its sulfophilic surface with 3D conductive construction and excellent catalytic property for LiPSs, the redox kinetics of sulfur species can be effectively accelerated. When it is simultaneously used as sulfur host and coating materials of PP separator, the corresponding cells show excellent cycling durability (620.3 mAh g−1 after 550 cycles at 2 C), attractive rates performance (844 mAh g−1 even at 10 C), and a high capacity of 1023 mAh g−1 after 50 cycles at 0.2 C with sulfur loading of 6.24 mg cm−2. This work paves a promising pathway to design advanced multifunctional regulators of LiPSs for exploiting high-performance lithium-sulfur batteries.