Synthesis and characterization of sulfur/carbon/porous nanostructured V₂O₅ composite cathodes for lithium sulfur batteries

Porous nanostructured V₂O₅ (PN-V₂O₅) was prepared by a facile spray pyrolysis and used as additive to synthesize sulfur/carbon/PN-V₂O₅ (S/C/PN-V₂O₅) composite by a combination of wet-ball-milling and heat treatment. The meso- and macropores in PN-V₂O₅ were confirmed by pore size distribution, which provided the favorable space to accommodate sulfur. The X-ray diffraction analysis showed that the crystal structures of S and V₂O₅ could be preserved below the heating temperature of 160 °C and that high heating temperature (200 °C) will result in reaction between S and V₂O₅. The pore size distribution curves of S/C/PN-V₂O₅ composites revealed that the penetrated S in PN-V₂O₅ pores mainly occupied the mesopores and macropores, which was further confirmed by a typical cross-sectional PN-V₂O₅ with Auger analysis. The S/C/PN-V₂O₅ composite cathode exhibited a discharge capacity of 632 mAh g⁻¹ after 60 cycles at the current density of 100 mA g⁻¹ and the capacity retention of S/C/PN-V₂O₅ electrode was 27.3% higher than that of S/C electrode, demonstrating a better cycling performance.