Block-Copolymer assisted synthesis of hierarchical carbon monoliths suitable as supercapacitor electrodes

Abstract

Three dimensional (3D) hierarchical porous (micro-, meso- and macro-porous) carbon monoliths (HCMs) have recently been proposed as promising supercapacitor electrodes. In this work, we have further explored the use of block-copolymers as templates for the preparation of HCMs via condensation of resorcinol and formaldehyde (RF) and subsequent carbonization. The resulting HCMs exhibited a textured morphology consisting of a bicontinuous macroporous carbon network built of interconnected microporous carbon colloids, as demonstrated by nitrogen adsorption/desorption isotherms, mercury porosimetry and electron microscopy, in both scanning and transmission mode. Such a texture favored the performance of HCMs as supercapacitor electrodes, reaching remarkable values of capacitance of up to 198 F g⁻¹ (normalized by mass) and 34.5 μF cm⁻² (normalized by BET surface area). The first electrolyte infiltration into the micropore (prior capacitance measurements) was demonstrated to play a crucial role in the achievement of large capacitance values.