Facile synthesis of carbon sphere@Ni(OH)2 and derivatives for high-performance supercapacitors

Herein, Ni(OH)(2) on carbon sphere nanostructure together with its derivatives, including NiO on carbon sphere, yolk-shell structure of NiO on carbon sphere and hollow NiO, were prepared with precise control and then applied as supercapacitors. Among them, NiO on carbon sphere exhibits a high specific capacitance (270.4 F g(-1) at 0.5A g (-1)), excellent rate performance (77.6% retention with 20-time current density increase) and good cycling stability (75.9% retention after 2000 cycles). The results indicate that carbon sphere plays a significant role in enhancing the electrical conductivity and electronic transportation process, ensuring the synergistic effects between carbon sphere and NiO shell.