3D 3C-SiC/Graphene Hybrid Nanolaminate Films for High-Performance Supercapacitors.

Abstract

High-performance supercapacitors feature big and stable capacitances and high power and energy densities. To fabricate high-performance supercapacitors, 3D 3C-SiC/graphene hybrid nanolaminate films are grown via a microwave plasma-assisted chemical vapor deposition technique. Such films consist of 3D alternating structures of vertically aligned 3C-SiC and graphene layers, leading to high surface areas and excellent conductivity. They are further applied as the capacitor electrodes to construct electrical double layer capacitors (EDLCs) and pseudocapacitors (PCs) in both aqueous and organic solutions. The capacitance for an EDLC in aqueous solutions is up to 549.9 µF cm-2 , more than 100 times higher than that of an epitaxial 3C-SiC film. In organic solutions, it is 297.3 µF cm-2 . The pseudocapacitance in redox-active species (0.05 Fe(CN)6 3-/4- ) contained aqueous solutions is as high as 62.2 mF cm-2 . The capacitance remains at 98% of the initial value after 2500 charging/discharging cycles, indicating excellent cyclic stability. In redox-active species (0.01 m ferrocene) contained organic solutions, it is 16.6 mF cm-2 . Energy and power densities of a PC in aqueous solution are 11.6 W h kg-1 and 5.1 kW kg-1 , respectively. These vertically aligned 3C-SiC/graphene hybrid nanolaminate films are thus promising electrode materials for energy storage applications.