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

Abstract

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[Formula: see text]F g[Formula: see text] at 0.5[Formula: see text]A g[Formula: see text]), 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.