Electrospun β-Mo₂C/CNFs as an efficient sulfur host for rechargeable lithium sulfur battery

Lithium–sulfur (Li–S) battery with a high energy density is being considered the promising energy storage devices. However, it is a challenge to develop high performance electrodes for commercialization of rechargeable Li–S battery system because of the dissolution of polysulfides during charging and discharging process and the insulating nature of sulfur. In this work, we firstly demonstrate the novel host material of β-molybdenum carbide/carbon nanofibers (β-Mo₂C/CNFs) with good electrical conductivity and porous structure, which is synthesized via the facile one-pot electrospinning method and subsequent thermal treatment to impregnate sulfur in Li–S battery. The as-prepared β-Mo₂C/CNFs act as polysulfide reservoirs to alleviate the shuttle effect by the physical and chemical adsorption. Meanwhile, the mesoporous structure of β-Mo₂C/CNFs can facilitate the electron transport for surface reactions and improve the reaction kinetics. It is demonstrated that β-Mo₂C/CNFs/sulfur composite displays a high lithium-ion diffusion coefficient, a low interfacial resistance and excellent electrochemical performance than that of CNFs/sulfur and pure sulfur.