Influence of Poly(Vinylpyrrolidone) on the Synthesis of LiV₃O₈/LiV₂O₅ by Rheological Phase Reaction Method for Supercapacitor Application

A facile rheological phase reaction (RPR) approach has been used to synthesize the LiV₃O₈/LiV₂O₅ (LVO) mixed phase metal oxide for aqueous supercapacitor application. The influence of poly(vinylpyrrolidone) (PVP) on the synthesized LiV₃O₈/LiV₂O₅ mixed phase metal oxide was studied. PVP added LiV₃O₈/LiV₂O₅ (PLVO) was found to have dense nanowires as observed from field-emission scanning electron microscopy (FESEM) analysis, which was by the influence of PVP in synthesis process. Energy dispersive x-ray (EDAX) analysis shows the formation of more oxygen vacancies and carbon sites in the PLVO. For a current density of 1A/g, the above material exhibited a high initial specific capacitance of 194 F/g in a three-electrode cell with 1 M LiNO₃ aqueous electrolyte. The material exhibited an excellent cyclic stability of 72.53%, even after 5000 cycles at a current density of 5 A/g. The morphology of the material was found to play a prominent role in the high capacitance and cyclic ability. Symmetric supercapacitor constructed using PLVO showed a highest specific capacitance of 120 F/g at 0.25 A/g, with 72.87% capacitance retention at 1 A/g after 150 cycles.