Amorphous Ni(OH)(2) @ three-dimensional Ni core-shell nanostructures for high capacitance pseudocapacitors and asymmetric supercapacitors

A complex hydroxide/metal Ni(OH)(2)@Ni core-shell electrode was developed for a high-performance and flexible pseudocapacitor. Compared to the conventional Ni(OH)(2) electrode, the as-prepared amorphous Ni(OH)(2)@ three-dimensional (3D) Ni core-shell electrode shows a large specific capacitance of 2868 F g(-1) at a scan rate of 1 mV s(-1) and a good cycling stability (3% degradation after 1000 cycles) at a scan rate of 100 mV s(-1). Furthermore, the high rate capability with a specific capacitance of 2454 F g(-1) can be achieved at a charge-discharge current density of 5 A g(-1). An amorphous Ni(OH)(2)@ 3D Ni-AC based asymmetric supercapacitor could be cycled reversibly in the high-voltage region of 0-1.3 V, and the specific capacitance of 92.8 F g(-1) at 1 A g(-1). This research demonstrates that introduction of a metal core to conventional hydroxide supercapacitor electrodes could open up new opportunities for designing and developing high-performance supercapacitors.