N-Doped Graphene/Melamine Formaldehyde Composite Carbon Foam as a Binder-Free Electrode for Supercapacitors

A N-doped graphene/melamine formaldehyde composite carbon foam (G/C) with a porous structure was prepared by a physical foaming method and high-temperature carbonization. Samples of the G/C with various graphene content (i.e., 0%, 1% and 2%) were synthesized and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and field-emission scanning electron microscopy (FESEM). The XPS and TEM analyses show that the as-prepared G_2%/C foam has the highest nitrogen content of 14.7%, with an apparent porous structure. The electrochemical performances of the G/C samples were investigated by charge-discharge cycles. The G_2%/C exhibits a high capacitance of 619.3 Fg^-1 at a current density of 0.5 Ag^-1. The N-doped graphene/melamine formaldehyde composite carbon foam is a promising electric double-layer capacitor material for binder-free electrodes with excellent properties for supercapacitors.