Deposition of three-dimensional graphene aerogel on nickel foam as a binder-free supercapacitor electrode.

Abstract

We reported a new type of graphene aerogel-nickel foam (GA@NF) hybrid material prepared through a facile two-step approach and explored its energy storage application as a binder-free supercapacitor electrode. By simple freeze-drying and the subsequent thermal annealing of graphene oxide hydrogel-NF hybrid precursor, three-dimensional graphene aerogels with high mass, hierarchical porosity, and high conductivity were deposited on a NF framework. The resulting binder-free GA@NF electrode exhibited satisfactory double-layer capacitive behavior with high rate capability, good electrochemical cyclic stability, and a high specific capacitance of 366 F g(-1) at a current density of 2 A g(-1). The versatility of this approach was further verified by the successful preparation of 3D graphene/carbon nanotube hybrid aerogel-NF as a supercapacitor electrode, also with improved electrochemical performance. With advantageous features, such a facile and versatile fabrication technique shows great promise in the preparation of various types of carbon-metal hybrid electrodes.