Binder-Free and Flexible Carbon-Encapsulated Oxygen-Vacancy Cerium Dioxide Electrode for High-Performance Supercapacitor

• Published in: Journal of the Electrochemical Society 2021-01, Vol.168 (1), p.10536
• Main Authors: Kang, Huan, Xu, Liming, Cai, Yue, He, Yao, Xu, Jingkun, Zhou, Weiqiang
• Format: Article
• Language: English
• Subjects: Core-shell CeO; energy density; oxygen-vacancy; supercapacitor; wide potential window
• ISSN: 0013-4651; 1945-7111
• DOI: 10.1149/1945-7111/abdcc5

Binder-free and flexible oxygen-vacancy CeO 2 @C core–shell nanocomposites directly anchored on carbon cloth (CC) are prepared via a simple two-step process, in which CeO 2 nanoparticles are hydrothermally fabricated and mixed with polyvinylpyrrolidone (PVP) composites, subsequently, as-formed CeO 2 @PVP composites coated on CC are calcined at 700 °C. The morphologies, structures and electrochemical properties of as-obtained CeO 2 @C nanocomposites are studied by SEM, HRTEM, XRD, XPS and electrochemical techniques, respectively. The CeO 2 @C nanocomposites are composed of the CeO 2 core with diameter of about 10 nm and the carbon shell with thickness of about 1.5 nm. The electrochemical results reveal that the CeO 2 @C nanocomposites show a wide electrochemical active window of −1.0 ∼ 0.8 V and a specific capacitance of 141.56 F g −1 at 1 A g −1 in 1.0 M Na 2 SO 4 electrolyte. In addition, an asymmetric supercapacitor (ASC) assembled with CeO 2 @C and poly(3,4-ethylene dioxythiophene) (PEDOT) can work in the wide operational voltage region of 2.0 V and deliver the energy density of 11.12 Wh kg −1 at 2000 W kg −1 . The present study indicates that the CeO 2 @C will have a greater advantage in terms of energy density for CeO 2 and its carbon-based composites supercapacitor electrodes.