Electrochemistry of poly(1,5-diaminoanthraquinone) and its application in electrochemical capacitor materials

A poly(1,5-diaminoanthraquinone) [poly(DAAQ)], which is a conducting polyme r condensed with 1,4-benzoquinone, was studied electrochemically and was pr oposed as a new category of electrochemical capacitor material. In common n onaqueous media, the poly(DAAQ) showed two sets of reproducible redox coupl es for repeated cycles. The potential window of the material was in the ran ge from cn. -1.5 to +1.0 V (vs. Ag/AgCl). hz situ UV-visible spectroscopy s uggested that the redox couple observed around -1.5 V is responsible for th e quinone group and that around +1.0 V is due to the pi-conjugated system. The poly(DAAQ) showed high conductivity (0.3-2.0 Ohm(-1) cm(-1)) over a wid e range of potential (-2.0 to 0.8 V), which suggests extension of the pi-co njugated system. It is proposed here that one can construct an electrochemi cal capacitor device by utilizing poly(DAAQ) as both positive and negative electrodes. We constructed the poly(DAAQ)/poly(DAAQ) electrochemical capaci tor for test purposes. The poly(DAAQ)/poly(DAAQ) electrochemical capacitor exhibited high specific energy (25-46 Wh kg(-1)) and high specific power (1 0,200-30,500 W kg(-1)) at discharge rates from 30 to 90 C. (C) 2000 The Ele ctrochemical Society. S0013-4651(99)03-018-9. All rights reserved.