An asymmetric polymer capacitor was prepared from pyrene (PY), aniline (ANI), and commercially available activated carbon (AC) through a solvent-free preparation. PY and ANI were adsorbed into the AC host material in the gas phase and electrochemically polymerized exclusively inside the AC pores in an aqueous H2SO4 electrolyte (1 M). No volumetric expansion of the AC particles occurred upon the adsorption of monomers and their subsequent polymerizations; thus, the volumetric capacitance was enhanced by the inclusion of pseudocapacitive polypyrene (PPY) and polyaniline (PANI). The PPY and PANI structures formed inside the AC pores are very thin and have a large contact area with the conductive carbon surfaces. Therefore, the charge transfer distance between the polymers and the carbon surfaces was drastically shortened, significantly reducing the charge transfer resistance; i.e., high power density. The maximum volumetric capacitances for the PPY- and PANI-hybridized AC reached 314 and 299 F cm-3, respectively. Moreover, the strong adhesion derived from their large contact areas and adsorption capability of AC endow these materials with long cycle lifetimes. The PPY- and PANI-hybridized AC have different redox potentials and can be assembled into an asymmetric capacitor. The volumetric capacitance obtained for the asymmetric capacitor further surpassed that of the symmetric capacitor consisting of pristine AC, with high power density and long cycle lifetimes.

We demonstrate reversible charge/discharge in ruthenocene, RuCp 2 (Cp = η 5 -C 5 H 5 ), using activated carbon (AC) as a support. RuCp 2 is supported in the micropores of AC as clusters consisting of multiple RuCp 2 molecules via gas-phase adsorption. Upon subsequent electrochemical oxidation using an aqueous H 2 SO 4 electrolyte, the clusters are disassembled and the RuCp 2 molecules are finely dispersed in the micropores. The resulting RuCp 2 has a large contact area with conductive carbon surfaces, thereby realizing rapid charge transfer at the contact interface. Consequently, rapid charge storage occurs via the reversible redox reaction of the supported RuCp 2 in aqueous H 2 SO 4 without dimerization or disproportionation reactions, which is confirmed by Xray absorption spectroscopy. Since hybridization can produce different properties of the host and guest materials, their infinite combinations would have the possibility to yield properties far surpassing those of existing materials.