Construction and electrochemical performances of the three-dimensional nano NiCo2O4

Bilayer NiCo2O4/NiCo2O4 nanosheet arrays on nickel foam (NF) are fabricated by a two-step solution-based method, which involves in hydrothermal process and chemical bath deposition. Compared with the monolayer NiCo2O4/NF electrode, the NiCo2O4/NiCo2O4/NF displays the unique micro-nanometer hierarchical and porours structure and has excellent pseudocapacitive behaviors in 6M KOH, which exhibits high specific capacitances of 2363.64 F g(-1) at a constant current density of 0.5 Ag-1, and 1454.55 F g(-1) at the higher current density of 8 Ag-1, and shows a favourable cycling stability of 77.5% retention after 1000 cycles.