▎ 摘　　要

Transition metal hydroxides and graphene composite holds great promise to be the next generation of high performance electrode material for energy storage applications. Here we fabricate the cypress leaf-like Cu(OH)(2) nanostructure/graphene nanosheets composite through one-step in situ synthesis process, employed as a new type of electrode material for high efficiency electrochemical energy storage in supercapacitors. A solution-based two-electrode system is applied to synthesize Cu(OH)(2)/graphene hybrid nanostructure, where anodic graphene nanosheets firmly anchor cathodic Cu(OH)(2) nanostructure due to the electrostatic interaction. The in situ self-assembly of Cu(OH)(2)/graphene ensures good structural robustness and the cypress leaf-like Cu(OH)(2) nanostructure prompt to form the open and porous morphology. The hybrid structure would facilitate charge transport and effectively mitigate the volume changes during long-term charging/discharging cycles. As a consequence, the Cu(OH)(2)/graphene composite exhibits the highest capacitance of 317 mF/cm(2) at the current density of 1mA/cm(2) and superior cyclic stability with no capacitance decay over 20,000cycles and remarkable rate capability at increased current densities.