Activated carbon aerogel containing graphene as electrode material for supercapacitor

Resorcinol–formaldehyde aerogel containing graphene oxide (RFGO) was prepared by a sol–gel polymerization of resorcinol with formaldehyde using polyethyleneimine (PEI)-modified graphene oxide, and activated carbon aerogel containing graphene (ACAG) was then prepared by a chemical activation with K2CO3. For comparison, graphene-free activated carbon aerogel (ACA) was prepared by the same method using graphene oxide-free resorcinol–formaldehyde aerogel. Non-activated carbon aerogel (CA) was also prepared. BET surface area and pore volume of ACA and ACAG were remarkably enhanced with well-developed porous structure compared to those of CA. Electrochemical performance of CA, ACA, and ACAG electrodes were measured by cyclic voltammetry and galvanostatic charge/discharge methods. ACAG showed higher specific capacitance than ACA with excellent supercapacitive behavior (300 F/g vs. 271 F/g). Equivalent series resistance (ESR) of ACAG (0.40 Ω) was smaller than that of ACA (0.57 Ω). The enhanced electrochemical performance of ACAG electrode was due to graphene layer of ACAG.