Preparation of an aqueous zinc ion rGH/V2O5 photorechargeable supercapacitor

Abstract

A photorechargeable supercapacitor was constructed using vanadium pentoxide (V₂O₅), reduced graphene oxide hydrogel (rGH), and zinc trifluoromethanesulfonate (Zn(CF₃SO₃)₂) as the photoanode, cathode, and electrolyte, respectively. The phase composition, microstructure, chemical structure, light absorption, and specific surface area of the synthesized products and the electrochemical performance of the rGH/V₂O₅ supercapacitor were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), Raman spectroscopy, UV-Vis spectroscopy, the Brunauer–Emmett–Teller (BET) method, and an electrochemical workstation, respectively. The results show that the device has a specific capacity of 164 F g⁻¹ at 0.5 A g⁻¹ under illumination with 95 mW cm⁻² light intensity, which is 20.5% higher than that under normal electrical charging. The supercapacitor has a 75% capacity retention rate and 100% coulombic efficiency, respectively, after 10 000 testing cycles under photoelectric synergistic charging and discharging. The as-constructed rGH/V₂O₅ photorechargeable supercapacitor exhibits promising application potential in electric vehicles and wearable electronics.