Porous hexagonal NiCo2O4 nanoplates as electrode materials for supercapacitors

Porous hexagonal NiCo2O4 nanoplates with an average diameter of about 100 nm and average thickness of about 25 nm have been successfully synthesized through a facile hydrothermal process and subsequent calcination in air. The calcination temperature involved has obvious affection upon the porous structures as well as the resultant capacitive performances. The NiCo2O4 sample obtained at a calcination temperature of 300 °C has a specific surface area of 67.1 m2 g−1, and a specific capacitance of 294 F g−1 at a current density of 1 A g−1. The long-term cycling stability test showed good rate retention of 89.8% of the highest capacitance after 3000 cycles. Therefore, the porous hexagonal NiCo2O4 nanoplates are excellent electrode material for supercapacitors.