Development of high performance EDLC based on carbon aerogel

Electric double-layer capacitors (EDLCs), which can store much more energy than conventional capacitors and offer much higher power density than batteries, have many potential applications such as back-up power sources, load-leveling, traction applications and electricity storage generated from solar or wind energy. Carbon aerogels are promising and innovative materials for EDLCs application because of their attractive properties such as a high electrical conductivity, controllable pore structure and highly useable surface area. However, the conventional method for carbon aerogel synthesis involves a supercritical drying step[1], which is very time-consuming and costly. In addition, carbon aerogels conventionally prepared provide predominantly mesopores and some mesopores are unnecessarily large. We will follow a modified synthesis method[2] with which aerogels can be made with slightly larger pores that may be dried under ambient conditions. To activate carbon aerogel and introduce a bimodal pore structure, we will follow the method described by Y. Hanzawa[3]. We will modify the activated carbon aerogels with a surfactant[4] to improve the wettability of the electrolyte to electrode, reducing the internal resistance and making the capacitance stay high at high frequency, and make carbon aerogels more suitable for EDLC applications. In this study, carbon aerogels will be characterized by BET measurement. EDLCs will be characterized by electrochemical impedance spectroscopy, voltammetry and charge-discharge techniques. [1] R.W. Pekala, Journal of Materials Science, 24(1989)3221 [2] R. Saliger et al, Journal of Non-Crystalline Solids, 221(1997)144. [3] Y. Hanzawa et al, Langmuir, 12(1996)6167 [4] B. Fang et al, "Surface modification of carbonaceous materials for EDLC applications ", (Submitted to Electrochimia Acta)