Electrochemical capacitors (ultracapacitors) are one approach to meeting the high power requirements for the energy storage system in an electric vehicle. Energy is stored in an electrochemical capacitor by charge separation in the double layer formed in the micropores of a very high surface area electrode material, which does not undergo chemical change as in a battery. Consequently, the material requirements for capacitors are very different from those of batteries. In the last several years, a number of promising material technologies have been identified for use in electrochemical capacitors. These include activated carbon fibers, foams, and composites, doped conducting polymers, and mixed metal oxides. The most important material property is its specific capacitance (F/gm or F/cm(exp3)). Carbon materials with specific capacitances of 100 to 300 F/gm have been developed. Doped polymer materials having specific capacitances of 300 to 400 F/gm are also being studied. In addition to high specific capacitance, the electrode material must also have a low electronic resistivity (less than 0.1 ohms cm) in order that charge can be distributed with minimum voltage drop in the electrode. Electrochemical capacitor cells have been fabricated using the various material technologies with both aqueous and organic electrolytes. Tests of the cells have shown near ideal charge/discharge characteristics - that is, the voltage versus time curves are nearly linear for constant current tests. Most of the cells have high power densities of 1 to 3 kW/kg. Numerous new materials for electrochemical capacitors have been identified, processed, and tested in electrodes and cells in recent years and progress is rapid in this relatively new field of research.


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    Titel :

    Material characteristics and the performance of electrochemical capacitors for electric/hybrid vehicle applications


    Weitere Titelangaben:

    Werkstoffkennwerte und Betriebsverhalten von elektrochemischen Energiespeichern für den Einsatz im Elektro-/Hybridantrieb


    Beteiligte:
    Burke, A.F. (Autor:in) / Murphy, T.C. (Autor:in)


    Erscheinungsdatum :

    1995


    Format / Umfang :

    21 Seiten, 8 Bilder, 5 Tabellen, 29 Quellen




    Medientyp :

    Aufsatz (Konferenz)


    Format :

    Print


    Sprache :

    Englisch





    Characterization of Electrochemical Capacitors for Electric/Hybrid Vehicle Application

    Burke, A. / American Institute of Aeronautics and Astronautics | British Library Conference Proceedings | 1994



    Thin-film high voltage capacitors for hybrid electric vehicle inverter applications

    Fairchold, M.Ray / Berlin, Carl W. / Sarma, D.H.R. et al. | Tema Archiv | 2012


    New Developments in Electrochemical Capacitors for Vehicle Applications

    Burke, A. | British Library Conference Proceedings | 2003