Research on Redox Properties of Novel Electronically Conducting Materials and Their Application

本研究计画之主题为将有机硫化合物与导电高分子偶联，以开发具有新颖或改良功能之电活性材料。这些复合材料的应用前景进行了检查，在高能量密度的锂二次电池的阴极材料。1.合成和电聚合的有机硫功能化吡咯单体的有机硫官能团，如硫醇和二硫化物共价引入到吡咯单体，试图提高导电聚合物对有机硫氧化还原反应的电催化活性。成功地合成了吡咯单体，并在其上连接了二硫键，进一步在电极表面电聚合。由此获得的聚吡咯衍生物与在相同条件下制备的未改性的原始聚吡咯相比显示出更高的电活性，这表明二硫基的氧化还原反应 ...更多信息 由于聚吡咯链的电催化作用而被活化。然而，二硫化物和硫醇之间的氧化还原转化的拉曼光谱和电化学石英晶体微天平迄今没有得到明确的证据。2.有机硫化合物在聚（3，4-乙撑二氧噻吩）（PEDOT）上的电催化氧化还原反应本研究首次证实了聚（3，4-乙撑二氧噻吩）（PEDOT）对有机硫氧化还原反应的高电催化活性。观察到有机硫化合物如2，5-二巯基-1，3，4-噻二唑（DMcT）的氧化还原反应在PEDOT修饰的碳电极上被有效地活化。PEDOT还电催化DMcT二聚体和低聚体的氧化还原反应。DMcT氧化还原反应的这种加速，这是必不可少的有机硫化合物的电池的实际应用，归因于PEDOT矩阵，其中DMcT被纳入电子性能。计时电位结果表明，DMcT在PEDOT修饰电极上的氧化还原反应足够快，即使在1.0 mA/cm^2的电解电流下，DMcT的库仑效率几乎为100%。少

The subject of this research project is to develop electroactive materials with novel or improved functionality by molecularly coupling organosulfur compounds and conducting polymers. The promise of these composite materials was examined in the application to a cathode material for lithium secondary batteries with high energy density.1.Synthesis and Electropolymerization of Organosulfur-Functionalized Pyrrole MonomersOrganosulfur functional groups such as thiols and disulfides were covalently introduced to a pyrrole monomer in an attempt to enhance electrocatalytic activity of conducting polymers toward organosulfur redox reactions. Pyrrole monomer, to which disulfide group was attached, was successfully synthesized and further electropolymerized at electrode surfaces. A polypyrrole derivative thus obtained showed higher electroactivity compared to that of unmodified, pristine polypyrrole prepared under the same condition, which suggested that the redox reaction of the disulfide group … More was activated due to electrocatalysis of polypyrrole chain. However, clear evidences for the redox transformation between disulfide and thiol have not so far obtained from Raman spectroscopy and electrochemical quartz crystal microbalance. Further characterization of the polymer is currently under way.2.Electrocatalytic Redox Reactions of Organosulfur Compounds on Poly(3,4-ethylenedioxythiophene) (PEDOT)In this study, high electrocatalytic activity of poly(3,4-ethylenedioxythiophene) (PEDOT) toward organosulfur redox reactions was confirmed for the first time. It was observed that redox reactions of an organosulfur compound such as 2,5-dimercapto-1,3,4-thiadiazole (DMcT) was efficiently activated at a PEDOT-modified carbon electrodes. PEDOT also electrocatalyzed the redox reactions of DMcT dimer and oligomers. Such acceleration of the DMcT redox reactions, which is essential to practical application of organosulfur compounds to batteries, was ascribed to electronic properties of PEDOT matrix, into which DMcT was incorporated. Chronopotentiometric results indicated that the redox reactions of DMcT were enough fast at PEDOT modified electrodes to sustain an electrolysis current even at 1.0 mA/cm^2 and coulombic efficiency for DMcT was virtually 100%. Less