Electric Double-Layer Capacitance of Inverse Opal Carbon Prepared Through Carbonization of Poly(Furfuryl Alcohol) in Contact With Polymer Gel Electrolyte Containing Ionic Liquid

Three-dimensionally periodic porous carbon membranes are prepared through the carbonization of poly(furfuryl alcohol) in the void spaces of opal materials consisting of monodispersed silica particles. Inverse opal carbon (IOC) membranes are obtained by the removal of silica templates. The obtained IOCs have three-dimensionally ordered macroporous structures and large specific surface areas due to the mesopores that are formed during the carbonization of the polymer precursor. IOC with three-dimensionally ordered 50-nm pores exhibits a large gravimetric capacitance of 120 F g(-1), as determined by using an ionic liquid electrolyte, 1-ethyl-3-methylimidazolium bis(trifluoromethane sulfonyl)amide ([C(2)mim][NTf2]); this capacitance is higher than that of conventional activated carbon. Furthermore, the combination of IOC and an ion gel electrolyte, consisting of network poly(methyl methacrylate) and [C(2)mim][NTf2], is demonstrated to be effective for achieving a solid-state, nonvolatile, and high-capacity electric double-layer capacitor. Moreover, because of the high ionic conductivity of the ion gel and the continuous ion-conduction path through the IOC membrane, the IOCs exhibit a large specific capacitance of 100 F g(-1) and a good rate capability, even at room temperature. Copyright (C) 2011 John Wiley & Sons, Ltd.