Preparation of novolac-type phenol-based activated carbon with a hierarchical pore structure and its electric double-layer capacitor performance

Preparation of novolac-type phenol-based activated carbon with a hierarchical pore structure and its electric double-layer capacitor performance

A hierarchical pore structured novolac-type phenol based-activated carbon with micropores and mesopores was fabricated. Physical activation using a sacrificial silicon dioxide (SiO2) template and chemical activation using potassium hydroxide (KOH) were employed to prepare these materials. The morphology of the well-developed pore structure was characterized using field-emission scanning electron microscopy. The novolac-type phenol-based activated carbon retained hierarchical pores (micropores and mesopores); it exhibited high Brunauer-Emmett-Teller specific surface areas and hierarchical pore size distributions. The hierarchical pore novolac-type phenol-based activated carbon was used as an electrode in electric double-layer capacitors, and the specific capacitance and the retained capacitance ratio were measured. The specific capacitances and the retained capacitance ratio were enhanced, depending on the SiO2 concentration in the material. This result is attributed to the hierarchical pore structure of the novolac-type phenol-based activated carbon.