Oxygen-vacancy VO ultrathin nanosheets adorned with PEDOT films as anodes for high-energy-density asymmetric supercapacitors

• Published in: New journal of chemistry 2023-10, Vol.47 (4), p.1883-1881
• Main Authors: Liang, Yanmei, Li, Danqin, He, Yao, Chao, Shixing, Zhang, Mingming, Zhao, Xueqian, Zhou, Weiqiang, Xu, Jingkun, Lu, Baoyang
• Format: Article
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/d3nj03429a

The development of asymmetric supercapacitors (ASCs) with high power and energy density is greatly restricted by the low capacitance of the anode materials. V 2 O 5 is a promising anode material with high theoretical capacity, but its low conductivity and high dissolution are not conducive to applications in energy storage. Herein, oxygen-vacancy PEDOT/V 2 O 5 ultrathin nanosheets with a thickness of about 4.4 nm are fabricated by the oxidative polymerization of EDOT monomers on V 2 O 5 nanosheets in the absence of other oxidants. The results of XPS and EPR confirm that the polymerization of PEDOT increases the oxygen vacancy concentration of V 2 O 5 . The PEDOT/V 2 O 5 nanosheets exhibit a specific capacitance of 406 F g −1 at 2 mV s −1 and excellent cyclic stability in the mixed organic electrolyte of dimethyl carbonate and ethylene carbonate. The energy density of ASCs composed of PEDOT/V 2 O 5 as the anode and activated carbon as the cathode reaches 65 W h kg −1 at a power density of 1490 W kg −1 . This means that PEDOT/V 2 O 5 has enormous potential in high-energy storage. Oxygen-vacancy PEDOT/V 2 O 5 nanosheets are obtained by the oxidative polymerization of EDOT on V 2 O 5 without other oxidants. The energy density of supercapacitors composed of PEDOT/V 2 O 5 and activated carbon reaches 65 W h kg −1 .