High-Voltage Asymmetric Electrochemical Capacitor Based on Polyfluorene Nanocomposite and Activated Carbon

An asymmetric electrochemical capacitor based on polyfluorene/carbon nanocomposite as positive electrode and activated carbon as negative electrode with nonaqueous electrolyte of tetraethylammonium tetrafluoroborate/propylene carbonate was investigated. From a galvanostatic charge–discharge test, the asymmetric capacitor test cell exhibited cell voltage as high as because of the high redox potential of the positive electrode ( vs ). Specific capacitance obtained for the test cell was (per electrode mass). The maximum energy density of the test cell was (per electrode mass), which was two times higher than that of typical double-layer capacitors based on activated carbon/activated carbon electrodes.