Ni(OH)2 nanosheets grown on graphene-coated nickel foam for high-performance pseudocapacitors

This paper reports a new two-step approach for growing hybrid Ni(OH)2/graphene structure on nickel foam for the first time. Firstly, graphene was synthesized on nickel foam, which was used both as catalyst and template, by a CVD method. Then the three-dimensional network structured Ni(OH)2 nanosheets were deposited on the graphene-coated nickel foam by a hydrothermal method. Electrochemical tests of this kind of electrode show a high specific capacitance (1440 F/g) and excellent cycling performance of ∼100% capacitance retention over 2000 cycles in a 1 M NaOH electrolyte. The presence of the graphene is critical to the high-performance of the electrode, and the experiment using the Ni(OH)2 on bare nickel foam exhibited a much worse cycling performance.

► Hybrid graphene/Ni(OH)2 structure on nickel foam.
► New two-step method.
► Enhanced cycling performance.