Unique 3D bilayer nanostructure basic cobalt carbonate@NiCo–layered double hydroxide nanosheets on carbon cloth for supercapacitor electrode material

A unique 3D bilayer nanostructure constructed with NiCo-layered double hydroxide nanosheets (NiCo LDH) has been constructed as an excellent electrode material. Herein, carbon cloth@basic cobalt carbonate nanosheet (CC@CCH NS) precursor is synthesized by simple hydrothermal method, and CC@CCH NS@NiCo LDH (CC@CCH@NC-DH) is synthesized via direct electrodeposition. The CC@CCH@NC-DH electrodes have been assessed and optimized by adjusting the feed ratio of Ni/Co in hydrothermal reaction. The SEM images show that the bilayer nanostructure of the CC@CCH@NC-DH electrode is the most obvious when the feed ratio of Ni/Co is 2:4. Electrochemical measurements confirm that the as-prepared CC@CCH@N2C4-DH electrode has high area-specific capacitance of 7.71 F cm−2 at 10 mA cm−2 and outstanding cycling stability at 35 mA cm−2. Superior rate performance of 72% is maintained even at high current density of 50 mA cm−2, indicating that the CC@CCH@N2C4-DH electrode is a very prospective electrode material.