Lithium-ion storage capacitors achieved by CVD graphene/TaC/Ta-wires and carbon hollow spheres. (15th January 2016)

• Record Type: Journal Article
• Authors: Zhao, Liwei; Li, Hongji; Li, Mingji; Xu, Sheng; Li, Cuiping; Qu, Changqing; Zhang, Lijun; Yang, Baohe
• Is Part Of: Applied energy. Volume 162(2016)
• Page Start: 197
• Page End: 206
• Publication Date: 2016-01-15
• Subjects: Hybrid capacitors -- Chemical vapor deposition -- Graphene -- Carbon hollow spheres -- Lithium-ion storage; Power (Mechanics) -- Periodicals; Energy conservation -- Periodicals; Energy conversion -- Periodicals; 621.042
• DOI: 10.1016/j.apenergy.2015.10.093
• Languages: English
• ISSNs: 0306-2619

Abstract

Graphical abstract: Highlights: Graphene/TaC/Ta wire electrode was prepared by CVD. Carbon hollow spheres as a solid electrolyte were prepared by hydrothermal. Specific capacitance of assembled capacitor reached 593 F g −1 at 10 A g −1 . The capacitor provided high energy and power densities (132 W h kg −1 /3.17 kW kg −1 ). The hybrid capacitor also exhibited a high stability during long endurance tests. Abstract: Lithium-ion storage capacitors were assembled using graphene/tantalum carbide/tantalum wire electrodes and carbon hollow spheres as electrolyte. The graphene/tantalum carbide layers were prepared by electron-assisted hot filament chemical vapor deposition; the carbon hollow spheres were synthesized by hydrothermal reaction and pyrolysis treatment. The specific capacitance of the capacitor was 593 F g −1 at a current density of 10 A g −1 . The capacitor showed excellent cycling stability, retaining 91.2% of its initial capacitance after 8000 cycles. Moreover, the capacitor provided a high specific energy density of 132 W h kg −1 at a high power density of 3.17 kW kg −1 . The high energy density is attributed to the widened operation window ranging from 0 to 3.0 V. The graphene layer of the electrode and carbon hollow spheres in electrolyte synergistic affect influence on the electrochemical performance of the capacitor are discussed. In addition, the use of a low-cost lithium salt, lithium chloride, is also featured in this paper.