Electrode Performance of S-doped Vanadium Pentoxide as Cathode Active Material for Rechargeable Magnesium Battery

Sulfur-added vanadium pentoxide (S-V2O5) powder prepared using our method was applied to the cathode active material used in magnesium rechargeable batteries. The preparation of S-V2O5 from a sulfur and vanadium pentoxide mixture was done with low-temperature plasma generated using carbon felt and 2.45-GHz microwave (CF-MWP). The S-V2O5 structure was investigated using XRD, XPS, Raman spectroscopy, and DRS-FTIR. Results revealed that the S-V2O5 particle surface contains sulfur atoms and that its structure is amorphous, like xerogel, although the bulk preserved the same structure as that of V2O5 crystal. Charge-discharge tests for S-V2O5 showed exceedingly high specific capacity of 300 mAhg−1, which far surpasses that of V2O5 (160 mAhg−1). The cycle performance of S-V2O5 (300 mAhg−1 after 20 cycles) was also more stable than that of V2O5 (70 mAhg−1 after first cycle). Moreover, the discharge voltage and the specific capacity did not degrade under any discharge rate condition from C/2 to C/10.