Shape-controlled synthesis of ternary nickel cobaltite and their application in supercapacitors

A facile hydrothermal method and subsequent annealing approach have been successfully developed to synthesize ternary nickel cobaltite hexapods, hexagonal prisms and nanowires. The products were investigated in detail by means of XRD, FESEM, TEM, HRTEM, BET, TGA and XPS. The hexapods have six clusters, and every cluster has many typical nanorods with diameter of about 10 nm and length of 1.2 μm. The nanowires are uniform in size, with diameters of about 10 nm. The hexagonal prisms with average size of about 120 nm have the highest BET specific surface area of 74.66 m2 g−1 and a pore volume of 0.1874 cm3 g−1, which exhibited superior specific capacitance of 663 F g−1 at a current density of 1 A g−1. It has impressive cycling stability with 88.4% initial capacitance retained after 5000 cycles at 4 A g−1, revealing the excellent stability of the electrode.