The preparation of poly(3-methylthiophene)/Pt electrode and charge/discharge Characteristic for electrochemical capacitor

• Main Authors: Shu-Min Tseng, 曾淑敏
• Other Authors: Jing-Shan Do
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/59829741965201926344

碩士 === 東海大學 === 化學工程學系 === 91 === The effect of preparing temperature, scanning number and the contain of water in the organic solvent on the properties of poly-3-methylthiophene (p(3-MeT)) were investigated in this thesis. The mechanism and the charge/discharge properties of p(3-MeT)/organic electrolyte/ p(3-MeT) electrochemical capacitor were proposed and discussed. The functional groups, the average conjugated chain length and UV-vis and the cyclic voltammetry (CV), respectively. The wave length of the adsorption peak in the UV-vis spectra of p(3-MeT) increased from 488 to 499 nm for decreasing the preparing temperature from 5 to —15oC. Furthermore, increasing the sweeping number for preparing p(3-MeT) from 3 to 5 the wave length of the adsorption peak of the UV-vis spectrogram of p(3-MeT) decrease from 503 to 488 nm. The experimental results indicated that the conjugated chain length of p(3-MeT) increased with the decrease of the temperature and the sweeping number for preparing p(3-MeT). The discharge capacities of the electrochemical capacitors were significantly affected by the potentials in the charge/discharge process. The maximum discharge capacities of the electrochemical capacitors were experimentally obtained to be 0.44, 10.06 and 8.31 mAh g-1, respectively, for the charge/discharge voltages of 0 ~ 3.0, 0 ~ 3.1 and 0 ~ 3.2 V based on p(3-MeT) prepared at —10oC with the sweeping number of 3. The discharge capacity increased with the charge/discharge voltage due to the activation of p(3-MeT) when the charge/discharge was located in the ranges of 0 ~ 3.0 and 0 ~ 3.1 V. The decrease of the discharge capacity of electrochemical capacitor was found due to the degradation of p(3-MeT) for the charge/discharge voltage of 0 ~ 3.2 V. The maximum discharge capacity increased from 6.9 to 10.63 mAh g-1 with the increase of the sweeping number for preparing p(3-MeT) at 5oC from 1 to 5. The maximum discharge capacity of the electrochemical capacitor were found to be 7.67 and 10.63 mAh g-1, respectively, based on p(3-MeT) prepared at the sweeping number of 5 when the temperature for preparing p(3-MeT) was 0 and 5 oC. The discharge capacity of electrochemical capacitor based on p(3-MeT) decreased with the temperature for preparing p(3-MeT). The experimental results were due that the dense structure of p(3-MeT) prepared at the lower temperatures resulted in the difficulty of the doping and undoping processes.