Type III electrochemical capactios based on poly(3-phenylthiophene) derivatives

摘要

The monomers 3-(4-cyanophenyl) thiophene, 3-(3, 4- difluorophenyl)thiophene and 3-(3, 4, 5- trifluorophenyl)thiophene were electrochemically deposited onto carbon paper electrodes. After polymerization the supported polymer electrodes were assembled into either a standard three electrode cell for multicycle testing or cut into shape and placed in a Tee-Cell in the Type III electrochemical capacitor configuration. Both symmetric, (comprised of identical supported polmer for the positive and negative electrodes) and asymmetric (comprised of supported electrodes utilizing different polymers) devices were tested. The devices were charged at constant current to high voltage (2.8 V) and discharged either via the application nof a constantcurrent (10-50 mA cm~(-2)) or by repeated short current pulses of 40 mA, 5 ms duration. Energy and power densities of up to 28 Wh kg~(-1) and 6.5 kW kg~(-1) were recorded for the constant current discharges while the pulse method yielded over 10~6 pulses. For the multicycle tests up to 99