聚噻吩(PT)、聚-3-甲基-噻吩(PMT)和聚-3,4-亚乙二氧基-噻吩(PEDT)作为超电容器电极材料的研究

Study of polythiophene,poly-3-methyl-thiophene and poly(3,4-ethylendioxythiophene) as supercapacitor electrode materials

通过线性扫描伏安法分别测试了电解质0.2M E t4NBF4的碳酸丙稀酯溶液在铂电极和玻璃碳电极上的电化学稳定窗口,结果表明,该电解质在玻璃碳电极上更稳定。通过电化学聚合在玻璃碳电极上分别合成了聚噻吩、聚-3-甲基-噻吩和聚-3,4-亚乙二氧基-噻吩,并通过循环伏安对三种导电高分子的掺杂特性进行了表征,分析比较三种导电高分子在电化学掺杂/去掺杂过程中的掺杂电位、可传递电荷、掺杂度和电荷捕获度可知,对于其掺杂电位,PT>PMT>PEDT;而对于去掺杂电荷和掺杂度,PEDT>PMT>PT,这表明PEDT是更有应用前景的超电容器电极材料。

The electrochemical stability window of the electrolyte, 0. 2M Et4NBF4 in propylene carbonate （PC）, is examined on platinum and glassy carbon, respectively, by linear scanning voltammetry （LSV）. The result indicates that the electrolyte is more stable on glassy carbon than on platinum upon electrochemical redox reactions. Three conducting polymers, polythiophene （PT）, poly-3-methyl-thiophene （PMT） and poly（3,4-ethylenedioxythiophene） （PEDT） are synthesized by electro-polymerization of the corresponding monomers on glassy carbon electrodes. The p-doping/dedoping processes of PT, PMT and PEDT are characterized in PC containing 0.2M Et4NBF4 by cyclic voltammetry （CV）. The deliverable charge, doping level and charge-trapping degree of PT, PMT and PEDT obtained from CVs were compared to one another. The results demonstrate that p-doping of the three polymers are at potential values on the order of PT〉PMT〉PEDT, but the de-doping charge and the doping level of them are on the order of PEDT〉PMT〉PT. It suggests that PEDT is a potential electrode＇ material for supercapacitor application.