Preparation of Hierarchical Porous Carbon Aerogels by Microwave Assisted Sol-Gel Process for Supercapacitors

Low-cost resorcinol formaldehyde (RF) organic aerogels were prepared by using resorcinol and formaldehyde as precursors, and sodium hydroxide as a catalyst through a single-mode microwave radiation-assisted sol-gel method and ambient temperature drying. Because of the ring focusing and power-max technology, the fabrication procedure of carbon aerogels (CAs) are much easier, faster, and cheaper than traditional methods. The RF aerogels were then pyrolysized at 900 degrees C, and the KOH activation process was used to further dredge micropores in the carbon aerogels. The CAs were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen adsorption/desorption, and a series of electrochemical tests. The KOH activated carbon aerogels with 3D-nano-network structure exhibited a high specific surface area of 2230 m(2) g(-1) with appropriate pore volumes of micro-, meso-, and macropores. The specific capacitance of CAs activated by KOH measured in a two-electrode cell was 170 F g(-1) at 0.5 A g(-1) with excellent rate capability and cycle stability in 6 M KOH electrolyte.