Binderfree synthesis of high-surface-area carbon electrodes via CO2 activation of resorcinol–formaldehyde carbon xerogel disks: Analysis of activation process

High-surface-area carbon xerogels were prepared in the form of disks via carbonization of precursor resorcinol–formaldehyde (RF) polymer disks and subsequent activation of the resultant RF carbon xerogels by CO2. RF carbon xerogels allow the preparation of a set of pre-activated carbon disks having different mesopore volumes. Analysis of the relationship between the mesopore volume of the samples and their CO2 activation efficiency showed that the presence of mesopores is crucial for obtaining a high-surface-area carbon with minimal burn-off of carbon atoms. Activation of an RF carbon disk with a mesopore volume of 1.0 cm3 g−1 up to a burn-off of 81% yielded an activated carbon disk with a high BET surface area of ∼3000 m2 g−1. Such disks could be readily used as electrode materials for an electric double layer capacitor without filler or binder addition and exhibited competitive EDLC performance against other electrode materials previously reported.