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Updated: Jan 26, 2026

Tuning Oxide Properties by Oxygen Vacancy Control During Growth and Annealing
Published on: June 9, 2023
Tailoring Energy and Power Density through Controlling the Concentration of Oxygen Vacancies in V2O5/PEDOT
Wenchao Bi1,2, Evan Jahrman3, Gerald Seidler3
1Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, School of Physics Science and Engineering , Tongji University , Shanghai 200092 , China.
Abstract:
Oxygen vacancies (Vö) play a crucial role in energy storage materials. Oxygen-vacancy-enriched vanadium pentoxide/poly(3,4-ethylenedioxythiophene) (Vö-V2O5/PEDOT) nanocables were prepared through the one-pot oxidative polymerization of PEDOT. PEDOT is used to create tunable concentrations of Vö in the surface layer of V2O5, which has been confirmed by X-ray absorption near edge structure (XANES) analysis and X-ray photoelectron spectroscopy (XPS) measurements. Applied as electrode materials for supercapacitors, the electrochemical performance of Vö-V2O5/PEDOT is improved by the synergistic effects of Vö in V2O5 cores and PEDOT shells with rapid charge transfer and fast Na+ ion diffusion; however, it is compromised subsequently by excessive Vö in consuming more V5+ cations for Faradic reactions. Consequently, the specific capacitance and the energy density of Vö-V2O5/PEDOT nanocables are significantly enhanced when the overall concentration of Vö is 1.3%. The migration of Vö renders an increased capacitance (105% retention) after 10 000 cycles, which is verified and corroborated with density functional theory simulations and XANES analysis. This work provides an illumination for the fabrication of high-performance electrode materials in the energy storage field through Vö.
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