Synthesis of Co–Ni Oxides @ CNTs Nanoflowers and Their Electrochemical Performance in Supercapacitors

The development of novel electrode materials with high energy density and long cycling life represents a new and promising direction in supercapacitors. The cobalt-nickel oxides @ CNTs nanoflowers with different ratios of cobalt and nickel as active materials were obtained by hydrothermal synthesis and thermal annealing. Electrochemical property measurements indicated that the specific capacitance can be up to 936.7 F/g when the ratio of the cobalt and nickel was about 1: 1.5, and the materials maintained 83.7% capacitance retention after 3500 continuous charge-discharge cycles at the density of 5 A/g. As a result, the cobalt-nickel oxides @ CNTs nanoflowers is a prospective candidate of electrode material for the micro-energy storage devices.