Cobalt-nickel composite films synthesized by chemical bath deposition method as an electrode material for supercapacitors

Cobalt-nickel (Co-Ni) composite thin films were fabricated on copper substrates using a simple chemical bath deposition route in an ammonia-complexed solution containing cobalt chloride and nickel chloride. The structural and morphological properties of the film confirmed that the chemically deposited Co-Ni composites formed in the hydroxide phase and were well covered with irregular shaped nano-platelets. The chemically deposited Co-Ni composite electrode exhibited a maximum specific capacitance of 324 F/g, which was much larger than that of the pristine components. The cyclic voltammetry and charge-discharge test showed that the capacitance of the chemically deposited Co-Ni composite electrode mainly consisted of a pseudocapacitance.