Mesoporous hexagonal nanorods of NiCo₂O₄ nanoparticles via hydrothermal route for supercapacitor application

Binary metal oxide with a mesoporous microstructure has been considered a potential candidate electrode material for supercapacitor. The mesoporous microstructure of binary metal oxide improves electric conductivity. A mesoporous hexagonal microstructure of NiCo₂O₄ nanorods has been fabricated by a chemical hydrothermal method. Mesoporous hexagonal nanorods composed of small nanoparticles with an average thickness of 412 nm are prepared with a 14-hour hydrothermal reaction time. As synthesized, mesoporous hexagonal nanorods of NiCo₂O₄ as an electrode material show the highest specific capacitance of 1061 F/g and 184 mF/cm² areal capacitance. The specific energy and specific power density of the NiCo₂O₄ electrode are 39 WhKg⁻¹ and 683 Wkg⁻¹. The equivalent charge resistance (R_s) and charge transfer resistance (R_ct) of the NiCo₂O₄ electrode are 0.70 Ω and 43 Ω respectively. The NiCo₂O₄ electrode had an initial capacitance retention value of 81% after 3000 cycles.