Free Standing Flexible Lithium-Ion Polymer Electrolyte Membranes formed by Photopolymerization

技术概要：该项目的主要目标是（1）展示三元相图的基本理解如何为独立式柔性聚合物电池的简易制造提供指导，以及（2）阐明通过光刻法创建垂直排列的离子通道周期阵列的管理原则，并具有明确的域尺寸和周期性。通过光聚合诱导的相分离产生的这些对齐的通道将不仅用作离子导线（或微通道），而且还增加离子浓度而不牺牲独立式电池膜的机械强度和完整性。在开发用于太阳能电池应用的有机材料以及在可再充电聚合物电池中有效的Li+离子传输中，高度寻求具有垂直取向的通道的这种周期性阵列以增强电子/激子传输。该项目的重点是确定低共熔相图作为抑制和/或消除聚乙二醇二丙烯酸酯（PEGDA）/丁二腈（SCN）/双（三氟甲基磺酰基）酰亚胺锂（LiTFSI）的二元和三元混合物中不需要的成分晶体的一种手段。 本系统的独特之处在于PEGDA的双交联不仅提供了改进的机械强度和网络的完整性，而且还增加了通过未扰动通道的离子传输。此外，由于界面面积的增加和与SCN的腈基的络合，对齐的定向通道结构也将增加离子存储容量。另一个优点是SCN可以有效地溶解离子盐，并且还可以完全消除不期望的LiTFSI晶体。更重要的是，所制造的聚合物电解质膜是不需要有机溶剂的自支撑膜，并且在环境温度下具有高电导率（7.1 × 10 -3 S/cm）。所制造的聚合物电解质膜可以在40-80 ℃的宽温度范围内操作。非技术概述：本项目的目标是研究和开发用于“绿色”电动车辆的轻质和可充电的独立式聚合物锂离子电池。与传统的电解质电池不同，本发明的聚合物电解质膜不含有毒或易燃的有机溶剂，因此可以避免诸如溶剂泄漏或电池燃烧的安全问题。 本发明的聚合物电解质可模塑成任何形状或形式，因此它应该具有更广泛的用途。 圆柱形态沿着膜厚度方向垂直排列的策略将进一步改善通过通道的离子传输，并由于表面/界面面积的增加而增强离子存储容量。由此获得的知识可以在本项目范围之外进行转让，特别是用于开发太阳能电池和信息技术中的光电转换的有机材料。这个项目将教育研究生和本科生，他们将接触到聚合物材料科学，工程数学和电化学的多学科研究。研究成果将通过PI的网站或阿克伦全球聚合物学院的远程学习计划向公众传播，该学院为高中科学教师及其学生举办研讨会。

TECHNICAL SUMMARY: The principal objectives of this project are (1) to demonstrate how the fundamental understanding of ternary phase diagrams may provide guidance to facile fabrication of free-standing flexible polymer batteries and (2) to elucidate governing principles for creation of periodic arrays of ionic channels aligned homeotropically via photolithography and having well defined domain size and periodicity. These aligned channels produced by photopolymerization-induced phase separation will not only serve as ion conducting wires (or micro-channels), but also increase the ion concentration without sacrificing the mechanical strength and integrity of the free-standing battery membranes. Such periodic arrays of channels with perpendicular orientation have been highly sought for enhanced electron/exciton transport in the development of organic materials for solar cell applications as well as for efficient Li+ ion transport in rechargeable polymer batteries. This project focuses on determination of the eutectic phase diagram as a means of suppressing and/or eliminating undesirable constituent crystals in the binary and ternary mixture of polyethylene glycol diacrylate (PEGDA)/succinonitrile (SCN)/lithium bis-(trifluoromethylsufonyl)imide (LiTFSI). The uniqueness of the present system is that photolithographic crosslinking of PEGDA not only affords improved mechanical strength and integrity of the networks, but also increases the ion transport through the unperturbed channels. Moreover, the aligned oriented channel structure will also increase the ion storage capacity due to increase in interface areas and complexation with nitrile groups of SCN. Another advantage is that SCN can effectively ionize the ionic salts and also completely eliminate the undesirable LiTFSI crystals. More importantly, the fabricated polymer electrolyte membrane is a free-standing film that requires no organic solvent and has a high conductivity (7.1x10-3 S/cm) at ambient temperature. The fabricated polymer electrolyte membrane may be operated over a wide temperature range, from 40-80 deg C.NON-TECHNICAL SUMMARY: The goal of this project is to study and develop lightweight and rechargeable free-standing polymer lithium ion batteries for "green" electric vehicles. Unlike conventional electrolyte batteries, the present polymer electrolyte membrane contains no toxic or flammable organic solvent and thus the safety issue such as solvent leakage or battery combustion may be avoided. The present polymer electrolyte is moldable in any shape or form, and thus it should find broader utility. The strategy of the perpendicular alignment of cylindrical columnar morphology along the film thickness direction will further improve ion transport through the channels and enhance ion storage capacity due to increase in surface/interface areas. The knowledge thus acquired can be transferred beyond the scope of the current project, specifically to development of organic materials for solar cells and photo-optical switching in information technology. This project will educate graduate and undergraduate students who will be exposed to multi-disciplinary research in polymer materials science, engineering mathematics, and electrochemistry. The research outcomes will be disseminated to the public through the PI's website or distance-learning programs of the Akron Global Polymer Academy, which conducts workshops for high-school science teachers and their students.