Electrospun nickel copper oxide/carbon fiber nanocomposites as supercapacitor electrode material with superior electrochemical performance

The porous fiber structure is advantageous for supercapacitor electrode material owning to flexibility, tunable porosity and large specific surface area. Nickel oxide (NiO) is a promising supercapacitor electrode material because of its low cost, friendly environment as well as high specific capacitance, but its poor electronic conductivity limits its application in practice. Doping appropriate transition metal ions is an excellent means of adjusting the structure of the electrons and improving conductivity, also is an effective way to improve the capacity. In this work, the nickel copper oxide/carbon (NCO/C) fiber nanocomposites were prepared via electrospinning and calcination treatment. NCO nanoparticles are decorated on the carbon nanofiber skeleton, which not only guides the growth of NCO nanoparticles and prevents agglomeration, but also acts as a conductive network to facilitate electron transfer. The electrochemical properties of NCO/C fiber nanocomposites affected by the copper dosage in the precursor solution and the calcination temperature were investigated. The optimized NCO/C fiber nanocomposites electrode achieves excellent electrochemical properties (277 C g–1 at 0.5 A g–1) because of generous specific surface area and excellent electrical conductivity. The asymmetric supercapacitor (ASC) device exhibits an energy density of 48.1 Wh kg–1 at 560.6 W kg–1. Excellent cycling performance with 95% capacitance retention was achieved after 5000 cycling tests at 1 A g–1. The results show that copper introduction is an effective way and that the porous NCO/C fiber nanocomposites are promising electrode materials for supercapacitors.