Synthesis and characterization of sulfur-carbon-vanadium pentoxide composites for improved electrochemical properties of lithium-sulfur batteries

Sulfur (S)-carbon (C)-vanadium pentoxide (V2O5) composites were prepared by wet ball milling, and their physical and electrochemical properties were evaluated. Firstly, the effect of the carbon content of S-C composite electrodes on their physical and electrochemical properties was investigated. The S-C composite electrode with 60 wt.% S delivers a first discharge capacity of 1077 mAh g(-1). However, its capacity markedly decreases to 606 mAh g(-1) after 10 cycles, which corresponds to a capacity fading rate of 47 mAh g(-1), per cycle. To improve the electrochemical performance of the S-C composite electrode, carbon was partially replaced by V2O5. The S-C-V2O5 composite electrode with a composition of 60 wt.%-S, 30 wt.%-V2O5 and 10 wt.%-C exhibits a lower capacity fading rate of 23 mAh g(-1) per cycle in the first 10 cycles and better capacity retention than the S-C composite electrode over 50 cycles. (C) 2015 Elsevier Ltd. All rights reserved.