Free-standing graphene/bismuth vanadate monolith composite as a binder-free electrode for symmetrical supercapacitors |
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| Authors: | Lingjuan Deng Jiahuan Liu Zhanying Ma Guang Fan Zong-huai Liu |
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| Affiliation: | College of Chemistry and Chemical Engineering, Xianyang Normal University, Xianyang Shaanxi 712000 P. R. China, +86-29-33720704 ; Key Laboratory of Applied Surface and Colloid Chemistry, Shaanxi Normal University, Ministry of Education, Xi’an 710062 P. R. China ; School of Materials Science and Engineering, Shaanxi Normal University, Xi’an 710062 P. R. China |
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| Abstract: | Preparation of new types of electrode material is of great importance to supercapacitors. Herein, a graphene/bismuth vanadate (GR/BiVO4) free-standing monolith composite has been prepared via a hydrothermal process. Flexible GR sheets act as a skeleton in the GR/BiVO4 monolith composites. When used as a binder-free electrode in a three-electrode system, the GR/BiVO4 composite electrode can provide an impressive specific capacitance of 479 F g−1 in a potential window of −1.1 to 0.7 V vs. SCE at a current density of 5 A g−1. A symmetrical supercapacitor cell which can be reversibly charged–discharged at a cell voltage of 1.6 V has been assembled based on this GR/BiVO4 monolith composite. The symmetrical capacitor can deliver an energy density of 45.69 W h kg−1 at a power density of 800 W kg−1. Moreover, it ensures rapid energy delivery of 10.75 W h kg−1 with a power density of 40 kW kg−1.A symmetrical supercapacitor with a high energy density has been assembled based on a free-standing GR/BiVO4 monolith composite. |
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