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

• A wet ball milling was conducted to synthesis S–C–V2O5 composite electrode.
• V2O5 additive led to further improve electrochemical performance of S-cathode.
• S–C–V2O5 composite electrode exhibited a first discharge capacity of 951 mAh g−1.
• The electrode (60 wt.%—S, 30 wt.%—V2O5, 10 wt.%—C) showed best battery performance.

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.

Figure optionsDownload as PowerPoint slide