Carbon-nanotube@graphene core–shell nanostructures as active material in flexible symmetrical supercapacitors. (3rd May 2019)

• Record Type: Journal Article
• Authors: Li, Kai; Li, Hongji; Li, Mingji; Li, Cuiping; Su, Lin; Qian, Lirong; Yang, Baohe
• Is Part Of: Composites science and technology. Volume 175(2019)
• Page Start: 92
• Page End: 99
• Publication Date: 2019-05-03
• Subjects: Carbon nanotubes -- Graphene -- Nano composites -- Supercapacitors -- Chemical vapor deposition (CVD); Composite materials -- Periodicals; Composite materials; Fibrous composites; Periodicals; 620.118
• DOI: 10.1016/j.compscitech.2019.03.013
• Languages: English
• ISSNs: 0266-3538

Abstract

Abstract: A carbon nanomaterial with core–shell structure was constructed from a composite of graphene and carbon nanotubes (CNT@G). A unique technology called polymer-assisted metal-catalyzed chemical vapor deposition (CVD) was used to first disperse a gold catalyst precursor, via the assistance of polyvinyl alcohol, on the CNT surface and then facilitate graphene growth by reducing the gold nanoparticles during CVD. A CNT@G/Ni electrode was then prepared from the CNT@G core–shell nanocomposite without using polymer bonding or annealing. The as-fabricated CNT@G/Ni electrode with mass loading of 3 mg cm −2 exhibited a high specific capacitance of 620.3 F g −1 at a scanning rate of 1 mV s −1 in the three-electrode configuration. When the mass loading of the electrode reached 5 mg cm −2, the areal capacitance was 781.2 mF cm −2 at a scanning rate of 1 mV s −1 . Symmetric supercapacitors were constructed using these CNT@G/Ni electrodes and a gel electrolyte consisting of carboxymethyl cellulose and potassium hydroxide. The devices offered advantages of flexibility, high operating voltage (1.8 V), high specific capacitance (268.7 mF cm −2 ), and high cycling performance (120.4% capacity retention after 10000 cycles).