In situ preparation of NiO nanoflakes on Ni foams for high performance supercapacitors

In this paper, a low-cost and pollution-free in situ synthesis of NiO nanoflakes on the Ni foams (NFs) with superior supercapacitance was proposed by employing a one-step thermal oxidation method. The optimal composite has porous coatings that are consist of a great deal of NiO nanoflakes. The unique porous structure in the composite provides efficient pathways for electrolyte ions to diffuse into the interior surfaces of the electrode materials. The composite exhibits a high specific capacitance (SC) of 1784.2 F/g at 5 mV/s, which is near the theoretical SC value of NiO. The composite also shows a good cyclic stability of 75.8% capacitance retention over 20000 charge/discharge cycles at 5 A/g. The excellent performance achieved with this thermal oxidation method makes the NiO/NFs composite potentially promising for supercapacitors applications. (C) 2015 Elsevier B.V. All rights reserved.