Graphene incorporated, N doped activated carbon as catalytic electrode in redox active electrolyte mediated supercapacitor

• Published in: Journal of power sources Vol. 337; pp. 25 - 35
• Main Authors: Gao, Zhiyong, Liu, Xiao, Chang, Jiuli, Wu, Dapeng, Xu, Fang, Zhang, Lingcui, Du, Weimin, Jiang, Kai
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.2017
• Subjects: Catalytic electrode; Graphene incorporation; N doped activated carbon; Pyrocatechol; Redox mediator; Graphene incorporation; N doped activated carbon; Pyrocatechol; Catalytic electrode; Redox mediator
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2016.10.114

Graphene incorporated, N doped activated carbons (GNACs) are synthesized by alkali activation of graphene-polypyrrole composite (G-PPy) at different temperatures for application as electrode materials of supercapacitors. Under optimal activation temperature of 700 °C, the resultant samples, labeled as GNAC700, owns hierarchically porous texture with high specific surface area and efficient ions diffusion channels, N, O functionalized surface with apparent pseudocapacitance contribution and high wettability, thus can deliver a moderate capacitance, a high rate capability and a good cycleability when used as supercapacitor electrode. Additionally, the GNAC700 electrode demonstrates high catalytic activity for the redox reaction of pyrocatechol/o-quinone pair in H2SO4 electrolyte, thus enables a high pseudocapacitance from electrolyte. Under optimal pyrocatechol concentration in H2SO4 electrolyte, the electrode capacitance of GNAC700 increases by over 4 folds to 512 F g−1 at 1 A g−1, an excellent cycleability is also achieved simultaneously. Pyridinic- N is deemed to be responsible for the high catalytic activity. This work provides a promising strategy to ameliorate the capacitive performances of supercapacitors via the synergistic interaction between redox-active electrolyte and catalytic electrodes. [Display omitted] •Graphene incorporated, N doped activated carbon was prepared by activation of G-PPy.•Wettable surface area, efficient electrons and ions mobility are ensured in GNAC.•Substantial pseudocapacitance from pyrocatechol containing electrolyte are offered.•Pyridinic N is responsible for the catalytic redox reaction of pyrocatechol mediator.