Preparation of amorphous detrital Ni (OH)2-reduced graphene oxide composite as electrode material for supercapacitor.

Amorphous Ni (OH)₂ nanobox-like materials were synthesized using Cu₂O as template. Ni (OH)₂/reduced graphene oxide (Ni (OH)₂/rGO) composites were prepared by a simple hydrothermal method. The results obtained from field emission scanning electron microscopy and transmission electron microscopy indicated that the Ni (OH)₂ nanobox structure broke into small pieces of 50–100 nm under high temperature and high pressure during the hydrothermal process, and successfully covered the entire graphene surface. Electrochemical studies showed that a specific capacitance of 626.84 F g⁻¹ was obtained at a current density of 1 A g⁻¹. When the current density increased from 1 to 5 A g⁻¹, the capacitance retention rate reached 50%. After 2000 consecutive charge–discharge cycles, the capacitance of Ni (OH)₂/rGO composite decreased 30% of initial capacitance compared to 55% for pure Ni (OH)₂. The rational design, interesting structure, and ideal electrochemical performance of this graphene-based composite indicate its potential application in high-energy storage systems. [ABSTRACT FROM AUTHOR]