Serrated-like NiCoO2 nanoarrays on Ni foam for high-performance supercapacitors

In this work, we have synthesized a nearly two-dimensional serrated structure of NiCoO2 on nickel foam by simple hydrothermal method and heat treatment. In this strategy, the serrated structure of NiCoO2 can be optimized by controlling the time of hydrothermal reaction. Electrochemical results show that its mass specific capacity reaches up to 778.5 C g(-1) (1.68 C cm(-2)) at current density of 0.5 A g(-1). Meanwhile, it is very impressed that the specific capacitance value of 603.5 C g(-1) can be maintained at a high current density of 40 A g(-1), indicating an excellent rate capability of as-prepared NiCoO2 material. Further, the practical application of serrated NiCoO2/NF as positive electrode is also evaluated by using asymmetric supercapacitor device. These excellent electrochemical properties further promote its application as a supercapacitor electrode.