Nickel metal–organic framework (Ni-MOF) derived NiO/C@CNF composite for the application of high performance self-standing supercapacitor electrode

Compared to conventional electrode, a self-standing structure electrode is an effective way to achieve high performance of supercapacitor by maximizing the use of active material. We present a new combination of nickel oxide–carbon composites fabricated by directly carbonizing a nickel metal–organic framework (Ni-MOF)@carbon nanofiber (CNF) for a self-standing electrode of the supercapacitor application. The new scheme utilizes the CNF film as a substrate with high electron transferring capability and as a backbone of a self-standing electrode as well. It is observed that the MOF-derived NiOs with a diameter of ~ 8 nm are uniformly distributed in the carbon matrix and result in the improvement of the electrical conductivity. The self-standing electrode, NiO/C@CNF composite, provides a high rate capability with high specific capacitances of 742.2 and 671.1F g⁻¹ (at 1 and 10 A g⁻¹), respectively. An asymmetric supercapacitor (ASC) constructed from the NiO/C@CNF and the activated carbon exhibits an excellent specific energy density of 58.43 Wh kg⁻¹ at a power density of 1,947 W kg⁻¹. It is also confirmed that the ASC shows a good cycle stability from the long-term cycling test. It is demonstrated that the proposed nickel oxide–carbon composite has a potential as promising self-standing electrode materials for supercapacitors.