EAPSI: Investigating the Fundamental Relationship Between Conductivity and Molecular Motion of Polymerized Ionic Liquids

当今的能源需求导致对锂离子电池和染料敏化太阳能电池等应用中改进的电解材料的需求增加。传统上，液体电解质由于其高离子电导率而被用于这些应用，但由于它们容易易燃性和泄漏，因此找到更安全的替代品至关重要。本研究将探讨聚合物离子液体（PILs）作为液体电解质的机械坚固替代品的结构和导电性能。这项研究将在日本大阪大学与世界领先的聚合物动力学专家井上忠志博士一起进行。聚合离子液体（PILs）被定义为单离子导电离子单体，其中一种离子结合在聚合物链中，而另一种离子名义上可以自由传输。虽然它们是传统液体电解质的一种更安全、机械稳定的替代品，但仍然存在的挑战是提高聚合物材料固有的低离子传输速率。利用更小的离子载流子可以增加材料的导电性，通过改变载流子的大小，可以更深入地了解导电性和结构之间的关系。因为改变材料结构会改变聚合物链的节段运动，井上正士博士在聚合物动力学方面的专业知识将极大地帮助理解结构、流动性和聚合物链弛豫之间的基本关系。本研究的结果将对目前对聚合物电导率的理解做出积极的贡献，为设计更安全、更高效的电解材料。该奖项属于东亚和太平洋暑期研究所项目，由美国国家科学基金会和日本科学促进会共同资助，支持一名美国研究生进行暑期研究。

Today's energy demands have led to an increased need for improved electrolytic materials in applications such as lithium ion batteries and dye-sensitized solar cells. Traditionally, liquid electrolytes have been used in these applications due to their high ionic conductivity, but because they are prone to flammability and leakage, it is crucial to find a safer alternative. This study will investigate the structure and conductive properties of polymeric ionic liquids (PILs) as mechanically robust alternatives to liquid electrolytes. This research will be conducted at Osaka University in Japan with Dr. Tadashi Inoue, a world-leading expert in polymer dynamics. Polymerized ionic liquids (PILs) are defined as single ion conducting ionomers, in which one of the ionic species is incorporated in the polymer chain while the other is nominally free to transport. Although they are a safer, mechanically stable alternative to traditional liquid electrolytes, the challenge that remains is increasing the low ion transport rates inherent to polymeric materials. Utilizing smaller ionic charge carriers should increase the conductivity of the material and by varying the size of the charge carrier, greater insight on the relationship between conductivity and structure can be obtained. Because changing the material architecture will change the segmental motion of the polymer chain, Dr. Tadashi Inoue's expertise in polymer dynamics will greatly aid in understanding the fundamental relationship between structure, mobility, and polymer chain relaxation. The results of this study will make a positive contribution to the current understanding of polymer conductivity for the design of safer and more efficient electrolytic materials. This award, under the East Asia and Pacific Summer Institutes program, supports summer research by a U.S. graduate student and is jointly funded by NSF and Japan Society for the Promotion of Science.