基于新型电化学方法探索电极固/液界面双电层形成机制

This proposal aims at figuring out formation of electric double layers by taking advantage of several novel techniques. Then we shall model the structure of electric double layers and offer some proposals to research on super capacitors. First, the ac-impedance data will be obtained at parallel symmetrical electrodes, by which permeation of solvent molecules into the gap between electrode and shielding material can be avoided; Second, supporting electrolyte being of suspension of polystyrene-sulfonic(or polyallylamine, polyaniline.etc.) group covered polystyrene latex particle instead of salts will be used. The conductive mechanism of latex polyelectrolyte shows partial supports by the thermodynamic theory that conductivity is supposed to be proportional to squares of the charge number. Third, by varying the distance between two electrodes, those distance related components detected from impedance measurement can be separated from capacitance part. Fourth, instead of fitting the results with equivalent circuits, we shall calculate the accurate capacitance value and inner layer resistance value by using the equivalent circuit which is composed of frequency-dependent double layer impedance in series with solution resistance. Based on these novel techniques, we expect a universally applicable model of EDLs demonstrating the formation of electric double layers with frequency dispersion. Then by adjusting those parameters such as size of solvent molecule, concentration of supporting salts, surface structure of modified electrode, we shall apply this model to other electrode and electrolyte. Finally, we shall examine the generalizability of the model, then, enrich the surface electrochemical theory, meanwhile, provide theoretical direction to researches into increasing the capacitance of super capacitor.

基于对称平行电极精确变距控制的电化学测试系统，采用具有不同粒度和不同功能壳层包裹量的聚离子壳核结构复合导电胶体颗粒（聚苯乙烯磺酸PSS、聚丙烯胺PAA、聚苯胺等）悬浮液作为支持电解质，进行低表观离子浓度下电极电解液界面双电层结构的研究。以不同粒度不同磺酸（丙烯胺）负载量的PSS（PAA）/PS作为支持电解质进行电化学测试，阐明其在低离子浓度下克服欧姆降的机理；平行电极通过变距控制获得不同距离下的阻抗数据，进而获得完全避免溶液电阻干扰的双电层阻抗数据；解释双电层电容频率弥散行为，对电极界面双电层形成机制分析建模，并将该电化学方法应用到其他电极材料和电解液中，通过改变溶剂分子尺寸，壳核结构胶体电解质浓度，电极材料表面结构，检验模型普遍适用性，扩充界面电化学理论，为超级电容研究提供理论指导。

双电层电容，因其储能快速高效低损耗，且充放电过程为纯物理过程，正成为人类应对能源危机解决方案中重要的一环-绿色高效储能技术。目前关于双电层电容的研究集中在电极电解液材料;鲜有研究关注双电层形成机理的基础研究。在绿色能源研究的另一战场， 1893年Wfllian Grove展示出的第一台燃料电池问世到电极过程动力学理论完善之间的半个多世纪，燃料电池的发展一直处于停滞状态，直至电极过程动力学理论的完善，燃料电池才有了长足的发展，目前的超级电容研究面临着与20世纪50年代前燃料电池研究同样的问题，所以，双电层结构的理论解析及其新型研究体系的开发迫在眉睫。.本项目基于对称平行电极精确变距控制的电化学测试系统，合成不同种类不同表面形貌(Pt线，多晶型MnO2,负载型TiO2纳米管阵列，聚苯胺石墨烯复合材料)的多种电极材料,合成不同粒度和不同功能壳层包裹量的聚离子壳核结构复合导电胶体颗粒（聚苯乙烯磺酸PSS、聚丙烯酸PSA）悬浮液作为支持电解质，进行低表观离子浓度下进行电化学测试，平行电极通过变距控制获得完全避免溶液电阻干扰的双电层阻抗数据，摈弃等效电路数学拟合的处理方法，开创一种对阻抗数据进行数学分离的方法获取纯粹的双电层电容值；解释双电层电容频率弥散行为，对电极界面双电层形成机制分析建模，数学描述了极性溶剂分子偶极子在固液界面上双电层形成中的贡献机制。