Cellulose derived fibrous vanadium-sulfide/carbon composite with enhanced lithium storage properties

Abstract

Vanadium-sulfides are considered as promising anodic materials for lithium-ion batteries (LIBs) due to their unique layered structures and high theoretical capacities. However, the main challenge of vanadium-sulfide as an electrode material is still faced with slow Li-ion diffusion kinetics and inevitable structural damage during charging/discharging processes. Herein, a series of bio-inspired hierarchical fibrous VS4/C composites were designed based on cellulose substance as the scaffold and carbon source via simple hydrothermal method. The resultant fibrous VS4/C composites possessed a three-dimensional porous network structure consisting of carbon fibers coated with VS4 nanosheets. As a consequence, the optimized VS4/C anodic materials exhibit high reversible capacities (953 mAh g−1 at 0.1 A g−1), good rate features (420 mAh g−1 at 2 A g−1), and fast diffusion kinetics. The superior electrochemical properties of the VS4/C composites are mainly attributed to the three-dimensional porous network structures combined with the carbon fibers matrix, which promotes the contact between the electrode and electrolyte, alleviates the structural damage of VS4, as well as facilitates the electron transfer and Li-ion diffusion during the cycling processes.