Simple synthesis of core-shell structure of Co–Co3O4 @ carbon-nanotube-incorporated nitrogen-doped carbon for high-performance supercapacitor. (20th January 2018)

• Record Type: Journal Article
• Authors: Zou, Yongjin; Cai, Chenglong; Xiang, Cuili; Huang, Pengru; Chu, Hailiang; She, Zhe; Xu, Fen; Sun, Lixian; Kraatz, Heinz-Bernhard
• Is Part Of: Electrochimica acta. Volume 261(2018)
• Page Start: 537
• Page End: 547
• Publication Date: 2018-01-20
• Subjects: Supercapacitors -- Co–Co3O4 -- Core-shell -- Graphitic -- Synergistic effect; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2017.12.184
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: Encapsulating transition metals or oxides in N -doped carbonaceous materials is a desirable strategy in the design of advanced energy materials in confined spaces. In this study, a core@shell structure of Co–Co3 O4 core particles enclosed in a shell of carbon-nanotube (CNT)-incorporated nitrogen-doped carbon (hereafter abbreviated as Co–Co3 O4 @CNT–NC) was synthesized via simple pyrolysis of a melamine–formaldehyde (MF) resin and cobalt acetate composite in a N2 atmosphere, followed by oxidation with H2 O2 . Because of the intimate contact between the Co–Co3 O4 core particles and the graphitic shells, the obtained samples showed excellent performance. The as-prepared Co–Co3 O4 @CNT–NC structure exhibited improved electrical conductivity, which is suitable for an electrode material in electrochemical capacitors. It can deliver a high specific capacitance of 823.4 F g −1 at a current density of 1 A g −1, as well as a capacitance retention of 93.6% after 10000 cycles. Moreover, an asymmetric two-cell supercapacitor composed of a Co–Co3 O4 @CNT–NC positive electrode and a reduced-graphene-oxide negative electrode exhibited a high energy density of 46.7 Wh kg −1 at 1601.1 W kg −1 . The easy preparation and high performance of the Co–Co3 O4 @CNT–NC composite make it an excellent material for supercapacitors application. Graphical abstract: Image 1