Abstract Carbon aerogels (CAs) were prepared via a sol–gel process by polymerization of phloroglucinol, resorcinol and formaldehyde using 2,4-dihydroxybenzoic acid as catalyst with freeze-drying. The electrochemical properties were characterized using cyclic voltammetry, galvanostatic charge–discharge measurements and electrochemical impedance spectroscopy (EIS). The specific capacitance of corresponding CAs was up to 131 F g?1 and 105 F g?1 at the density of 0.5 A g?1 and 1.0 A g?1, respectively.