Designer Chemistry of Ionic Liquids and ion Gels

离子导电材料是电化学能量存储和能量转换装置必不可少的材料，如电池、电容器、燃料电池和太阳能电池。近年来，离子导电材料也被应用于软执行器中，可以应用于医疗、微机械和纳米技术。传统上，离子导电材料主要采用电解质溶液。例如，用于铅酸汽车电池的硫酸，用于手机和笔记本电脑主要电源的锂离子电池的易燃有机电解质溶液。因此，大多数电化学装置不是固体装置，而是包括挥发性液体的液体装置。因此，如何使离子导电材料不挥发、不易燃、固体化一直是许多研究者研究的课题。离子液体是一种室温熔盐，由于其独特的性能，如不挥发性、不可燃性、热稳定性和化学稳定性、高离子电导率和宽电位窗等，成为人们关注的新型电解质材料。我们将注意力集中在离子液体和聚合物作为新型聚合物电解质的组合上，并提出在这些离子液体中对普通乙烯基单体进行原位自由基聚合，可以使离子液体和所得到的网状聚合物形成相容的组合。完全相容的组合是一种新型聚合物电解质，被称为“离子凝胶”，它是一种具有离子液体特性的固体电解质。如果离子液体具有面向任务的分子特性，离子液体和离子凝胶的应用范围将大大扩大。在这个项目中，我们的目标是探索以下基本和面向任务的属性。1)离子液体和离子凝胶中的离子动力学2)无水质子导电离子液体及其在100℃以上稳定的离子凝胶的设计3)兼具离子和电子导电的混合导电离子液体及其离子凝胶的设计主要利用PGSE-NMR技术结合电化学阻抗技术对离子动力学进行了探索。由组成离子液体的阳离子和阴离子的扩散系数，由核磁共振可由能斯特-爱因斯坦方程（λ_<NMR>）计算出离子电导率，而通过阻抗测量可得到实验电导率（λ_<imp>）。我们最近提出λ <NMR>/λ <imp>比值可以作为离子液体中离子状态的度量。在无水质子导电离子液体的设计方面，我们首次发现了新型的Bronsted酸碱离子液体是无水质子导体，它是由多种有机胺与双（三氟甲烷磺酰）亚胺的简单组合而成的，遵循了载体和Grotthuss机制的结合。当氧化还原偶对在离子液体中以高浓度溶解时，电子也在离子液体中移动。利用微电极技术揭示了离子液体中I^-/I_3^-氧化还原偶对的电荷输运随浓度的增加呈非线性增加。高浓度[I^-]和[I_3^-]氧化还原偶对的电荷输运异常可归因于I^-+I_3^-→I_3^-+I^-的交换反应。少

Ion-conducting materials are essential for electrochemical energy-storage and energy-conversion devices, such as batteries, capacitors, fuel cells, and solar cells. Recently, the ion-conducting materials are also utilized in soft actuators that can be applicable to medical use, micro-machine, and nano-technology, Conventionally, electrolyte solutions have been used as the ion-conducting materials. For instance, Sulfuric acid is used for lead-acid car batteries, flammable organic electrolyte solutions are used for lithium-ion batteries that are main power source of cellar phones and lap-top computers. As a result, the most of the electrochemical devices are not solid devises but liquid devices that include volatile liquids. Thus, it has been a subject of many researchers to make the ion-conducting materials non-volatile, non-flammable, and solid.Ionic liquids are room temperature molten salts and of great interest as new electrolyte materials, because of their unique properties such as … More non-volatility, non-flammability, thermal and chemical stability, high ionic conductivity, and wide potential window. We have directed out attention to the combination of the ionic liquids and polymers as new polymer electrolytes and proposed that in situ radical polymerization of common vinyl monomers in these ionic liquids affords compatible combinations of the ionic liquids and the resulting network polymers. Completely compatible combinations are new polymer electrolytes and named "ion gels" that are solid electrolytes with the characteristic properties of the ionic liquids. If task-oriented properties are molecularly designed in the ionic liquids, he scope of the utility of ionic liquids and ion gels may greatly expand. In this project we have aimed at exploring the following fundamental and task-oriented properties.1)Ion dynamics in ionic liquids and ion gels2)Design of anhydrous proton-conducting ionic liquids and their ion gels that are stable at the temperatures higher than 100℃3)Design of mixed-conducting ionic liquids and their ion gels that can conduct both ions and electronsThe ion dynamics has been mainly explored by using PGSE-NMR technique combined with electrochemical impedance technique. From the diffusivity for both of the cations and anion, consisting the ionic liquids, from he NMR, the ionic conductivity can be calculated from Nernst-Einstein equation (λ_<NMR>), while he experimental conductivity (λ_<imp>) can be obtained by the impedance measurements. We newly proposed that the ratio, λ_<NMR>/λ_<imp>, could be a measure of he state-of ions in the ionic liquids. As for the design of he anhydrous proton conducting ionic liquids, we have found for he first time that novel Bronsted acid-base ionic liquids, derived from a simple combination of a wide variety of organic amines with bis(trifluoromethane sulfonyl)imide, are anhydrous proton conductors, following the combination of the vehicle and Grotthuss mechanisms. Electrons are also mobile in the ionic liquids when a redox couple is dissolved in them at a high concentration. We have revealed that charge transport of an I^-/I_3^-redox couple in an ionic liquid nonlinearly increases with increasing the concentration by using microelectrode technique. This anomaly of the charge transport at high concentrations of the redox couple with comparable [I^-] and [I_3^-] can be attributed to the exchange reaction of I^-+I_3^-→I_3^-+I^-. Less