Dilute NiO/carbon nanofiber composites derived from metal organic framework fibers as electrode materials for supercapacitors

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2017-01, Vol.307, p.583-592
• Main Authors: Yang, Ying, Yang, Feng, Hu, Hongru, Lee, Sungsik, Wang, Yue, Zhao, Hairui, Zeng, Dehong, Zhou, Biao, Hao, Shijie
• Format: Article
• Language: English
• Subjects: Capacitance; Carbon nanofiber; In situ synthesis; Metal organic framework; Nickel oxide
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2016.08.132

Facile construction and evolution of Ni, Zn-containing metal organic framework fibers has been designed to in situ fabricate dilute NiO/carbon nanofiber composites as high-performance electrode materials. [Display omitted] •Dilute NiO/CNF composites fabricated by construction and evolution of Ni-ZnBTC fibers.•Combined advantages of porous carbon nanofibers and dispersed NiO particles.•Remarkable capacitance of 14,926Fg−1 per active mass of NiO.•Good rate capability and outstanding cycling stability up to 5000times. A new type of carbon nanofiber (CNF) dominated electrode materials decorated with dilute NiO particles (NiO/CNF) has been in situ fabricated by direct pyrolysis of Ni, Zn-containing metal organic framework fibers, which are skillfully constructed by assembling different proportional NiCl2·6H2O and Zn(Ac)2·2H2O with trimesic acid in the presence of N,N-dimethylformamide. With elegant combination of advantages of CNF and evenly dispersed NiO particles, as well as successful modulation of conductivity and porosity of final composites, our NiO/CNF composites display well-defined capacitive features. A high capacitance of 14,926Fg−1 was obtained in 6M KOH electrolyte when the contribution from 0.43wt% NiO was considered alone, contributing to over 35% of the total capacitance (234Fg−1). This significantly exceeds its theoretical specific capacitance of 2584Fg−1. It has been established from the Ragone plot that a largest energy density of 33.4Whkg−1 was obtained at the current density of 0.25Ag−1. Furthermore, such composite electrode materials show good rate capability and outstanding cycling stability up to 5000times (only 10% loss). The present study provides a brand-new approach to design a high capacitance and stable supercapacitor electrode and the concept is extendable to other composite materials.