Fabrication and electrochemical performances of hierarchical porous Ni(OH)2 nanoflakes anchored on graphene sheets

Hierarchical porous Ni(OH)2 nanoflakes anchored on graphene sheets has been fabricated by a facile chemical precipitation approach. The as-prepared Ni(OH)2/graphene composite as a electrode material for supercapacitors displays ultrahigh specific capacitance, superior cycling performance, and excellent rate capability. A maximum specific capacitance of 2194 F g−1 could be obtained at 2 mV s−1 in 6 M KOH aqueous solution. Meanwhile, the electrode exhibits excellent long cycle life along with 95.7% specific capacitance retained after 2000 cycle tests. Such composite is a highly promising candidate as electrode material for broad applications in energy conversion/storage systems.