Preparation of sucrose-based microporous carbons and their application as electrode materials for supercapacitors

Microporous carbon materials were prepared by carbonization of sulfuric acid-pretreated sucrose. The pore size and specific surface area of the samples were measured to be in the ranges of 0.7–1.2 nm and 178–603 m2/g, respectively. The pore parameters were found to depend strongly on the carbonization temperature. Raman spectra showed that the intensity of the G band was stronger than that of the D band for the samples obtained with carbonization temperatures above 800 °C. It was also found that the sample carbonized at 800 °C displayed the highest specific surface area with a main pore size of about 0.75 nm. This sample exhibited the highest specific capacitance (232 F/g) at a current density of 0.1 A/g and lowest electrical resistance based on the results of cyclic voltammetry, galvanostatic charge–discharge and electrochemical impedance spectroscopy (EIS). All samples displayed a good cycle performance behavior evaluated using both three-electrode and two-electrode cells. Based on the experimental results, the formation mechanism of the carbon materials as well as the relationship between the pore structure and their electrochemical properties were analyzed and discussed.

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► The microporous carbons have been prepared from sucrose directly by the carbonization method.
► The specific surface area and pore size of microporous carbons can be easily adjusted.
► The carbonization temperature is the only tunable parameter in fabricating the carbon materials.
► The microporous carbon with the highest surface area shows the best electrochemical performance.