Nickel and cobalt oxide composite as a possible electrode material for electrochemical supercapacitors

In this paper, a composite material, Ni0.37Co0.63(OH)2, is synthesized using the chemical precipitation method with the purpose to develop electrode materials for supercapacitors. Physical characterization using XRD, EDX, and SEM show that Ni0.37Co0.63(OH)2 possesses an amorphous structure, which leads to high specific capacitance of 1840 F g−1 in the potential window of 0–1.5 V. Cyclic voltammetry methods are employed to characterize the electrochemical properties of this electrode material in a N2-saturated alkaline solution. The results demonstrate that this material could give a two-electron redox process accompanied by two OH− ions. Cyclic voltammogram curves recorded for this Ni0.37Co0.63(OH)2 material are used to measure the specific capacitances at different potential scan rates. To validate this material for supercapacitor applications, charging/discharging tests are also conducted.

► Ni0.37Co0.63(OH)2 was synthesized as a possible electrode material for supercapacitors.
► A high specific capacitance of 1840 F g−1 was achieved in alkaline solution.
► The redox mechanism of two-electron accompanied by two OH− ion was proposed for Ni0.37Co0.63(OH)2.