Capacitive properties of low potential electro-polymerized polyfluorene and activated carbon composite electrode

Polyfluorene (PF) film has been successfully electropolymerized at lower potential (0.91 V vs. Ag/AgCl) in the mixed electrolyte of boron trifluoride diethyl etherate and trifluoroacetic acid. The PF film is characterized to have about 10 repeat units and no presence of ketonic defect site. UV-vis and photoluminescent spectral studies indicate that the PF film is blue light emitting. From cyclic voltammetry and galvanostatic charge-discharge tests in 1 M lithium perchlorate/acetonitrile electrolyte, the polyfluorene/activated carbon electrode shows a specific capacitance of 227.1 F g −1 (per active layer mass) and reversible redox reaction at the potential of 1.4 V in a three electrode configuration. An asymmetric electrochemical capacitor based on this composite electrode and activated carbon electrode exhibits a specific energy of 14.7 Wh kg −1 (per active layer mass). These results indicate that electrochemically prepared polyfluorene could be used as energy storage component for electrochemical application.