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

Abstract

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 632mAhg−1 after 60cycles at the current density of 100mAg−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.