Fabrication of binder-free electrode using reinforced resorcinol formaldehyde-based carbon aerogels

In this study, the electrochemical performance of the binder-free electrode based on the reinforced resorcinol formaldehyde (RF) carbon aerogels (CAs) was investigated for electric double layer capacitor (EDLC) application. Resorcinol formaldehyde aerogel (RF) was crosslinked using methylene diphenyl diisocyanate (MDI) and then pyrolyzed to produce carbon aerogel (CA). CA was subsequently activated using CO2 gas. The morphological changes due to the reinforcing and activation process were explored by SEM. The BET and BJH results showed an improvement in specific surface area and microporous volume. The CO2-activated CAs displayed up to twice more specific surface areas compared with the unactivated CAs. The compressive test verified an improvement of up to 5 times in the mechanical strength. In order to investigate the electrochemical performance, cyclic voltammetry (CV), charge/discharge (CD), and electrochemical impedance microscopy (EIS) were carried out. In an identical electrode weight, the specific capacity of binder-free electrodes increased about twice, in comparison with the common electrodes due to the removal of the binder and the collector. The highest specific capacitance among the fabricated samples was obtained for the reinforced and activated sample with resorcinol/catalyst (R/C) ratio of 700, which was equal to 55.5 F/g.