Synthesis of Cobaltous Nickel Oxide Core/Shell Nanowires for Supercapacitors

CoO/NiO core/shell nanowires (NWs) were synthesized using an efficient two-step approach. The detailed structural analysis through the transmission electron microscopy indicate that the CoO NW core is well enclosed by the NiO nanoflake shell with an unique nanoporous structure. Due to these structural advantages, when the obtained CoO/NiO core/shell NW material is used as a supercapacitor electrode, it presents a much enhanced capacitance (708 F.g(-1) at 1 A.g(-1)), better rate capability and excellent cycling performance (>80 % capacitance retention for 1000 cycles) compared with the single component samples. Besides, the synergetic interaction between the CoO NWs and NiO nanoflakes can produce more active sites for redox progresses than single material during the electrochemical reaction, which can provide synergistic effect to the capacitance and electrochemical stability.