Microwave-assisted synthesis of spherical β-Ni(OH)2 superstructures for electrochemical capacitors with excellent cycling stability

A novel single-step microwave-assisted process has been developed to synthesize spherical β-Ni(OH)2 superstructures without using any templates. Structure characterizations show that the spherical β-Ni(OH)2 composed of twisted nanosheets was obtained. The electrochemical properties of the as-prepared materials were evaluated by cyclic voltammetry and chronopotentiometry technology in 2 M KOH solution. Due to the unique morphology, the prepared β-Ni(OH)2 electrode displays a high specific capacitance of 2147 F g−1 at a discharge current of 1 A g−1 and outstanding cycling stability (99.5% capacitance retained after 2000 cycles), suggesting its potential application as an efficient electrode material for high-performance electrochemical capacitors.