Morphological characterization and impedance spectroscopy study of porous 3D carbons based on graphene foam-PVA/phenol-formaldehyde resin composite as an electrode material for supercapacitors

摘要

The design and fabrication of porous electrode materials is highly desirable for improving the performanceof electrochemical supercapacitors (ECs) and thus, it is important to produce such porous materials in largequantities. In this study, we used a microwave method to produce porous carbonaceous materialsdesignated as graphene foam/polyvinyl alcohol/formaldehyde (GF/PVA/F) and graphene foam-polyvinylalcohol/phenol-formaldehyde (GF/PVA/PF) from graphene foam, phenol formaldehyde and polyvinylalcohol (PVA). Scanning electron microscopy (SEM), Raman spectroscopy and Fourier-Transform InfraredSpectroscopy (FTIR) were used to characterize the surface morphology, structural defects and functionalgroups of the materials respectively. Based on these porous materials, the two symmetrical ECsfabricated exhibited a specific capacitance in the range of 0.62–1.92 F cm 2, phase angles of 81 and 84 and resistor–capacitor (RC) relaxation time constants of 4 and 14 seconds. The physicochemicalproperties of the electrolyte ion (diffusion) and its influence on the capacitive behavior of the porousmaterials were elucidated. These encouraging results demonstrate the versatile potential of these porousmaterials (GF/PVA/F and GF/PVA/PF) in developing high energy storage devices.