Synthesis and characterization of NiCo2O4 nanorods for preparation of supercapacitor electrodes

Here, a solvothermal method for synthesis of porous Ni–Co binary oxide (NiCo2O4) nanorods followed by thermal decomposition is described. The prepared nanorods were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer Emmett Teller (BET) methods. These porous NiCo2O4 nanostructures were promising candidates in the development of high capacity supercapacitors and having excellent cycling performance due to high specific surface area. In addition, the influence of annealing rate on the structure and electrochemical behavior of the synthesized nanorods was investigated. The results showed that the annealing rate had a direct effect on the crystalline properties and porosity of the nanorods and influenced on their electrochemical behaviors. The nanorods prepared by the annealing rate of about 1 °C min−1 indicated a rather high capacitance of 600 F g−1; moreover, a high retention capacitance of 80 % was achieved even after 1,500 cycles at 5 A g−1.