マグネシウム二次電池正極材料としての硫黄を添加した五酸化バナジウムの電極特性

抄録

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.