Vanadium carbide nanoparticles incorporation in carbon nanofibers for room-temperature sodium sulfur batteries: Confining, trapping, and catalyzing

Abstract

Room-temperature sodium-sulfur (RT Na-S) batteries have aroused extensive interest from researchers owing to the high theoretical volumetric energy density, nontoxicity and low-cost. However, poor conductivity of sulfur and high solubility of polysulfides in electrolyte are two major challenges for the practical application of the RT Na-S batteries. Herein, we report a three dimensional self-supported structure with Vanadium carbide (VC) nanoparticles embeddedin carbon nanofibers for RT Na-S batteries. Finally, the VC-CNFs@S electrode displays a reversible capacity of 379 mAh g−1 after 2000 cycles at 0.5C with a high capacity retention of 96.2%. Such outstanding electrochemical property is ascribed to the “confining – trapping – catalyzing” effect of VC-CNFs structure.