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.