Hierarchically porous nickel hydroxide/mesoporous carbon composite materials for electrochemical capacitors

Hierarchically porous composite materials consisting of nanoflake-like nickel hydroxide and mesoporous carbon are synthesized by a facile chemical precipitation method. The effects of microstructure and morphology of the carbon support on the electrochemical properties of the composite are also investigated. Structural characterizations have revealed that nanometer-sized nickel hydroxide nanoflakes can grow on the surface of mesoporous carbon supports. The mesoporous carbon-based composites shows better structure with interlaced nanoflakes and higher specific capacitance than activated carbon-based composite. The composite material with mesoporous carbon morphology of large particle size and long channel lengths possesses the highest specific capacitance of 2570 F/g, suggesting its potential applications as the electrode materials for electrochemical capacitors. The overall improved electrochemical behavior can be attributed to the unique structure design in nickel hydroxide/mesoporous carbon composite in terms of its nanostructure, large specific surface area and good electrical conductance.