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

通过光聚合形成的自立式柔性锂离子聚合物电解质膜

• 批准号: 1161070
• 负责人: Thein Kyu
• 金额: $ 41万
• 依托单位: University of Akron
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2016-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1161070&HistoricalAwards=false
• 关键词: Free; Standing; Flexible; Lithium; Ion

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.

技术摘要：本项目的主要目标是(1)展示对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)阐明通过光刻产生周期性排列的离子通道阵列的指导原则，这些离子通道通过光刻排列并具有明确的区域大小和周期。这些由光聚合诱导相分离产生的定向通道不仅可以作为离子导线(或微通道)，还可以在不牺牲自支撑电池膜机械强度和完整性的情况下增加离子浓度。这种具有垂直取向的周期性通道阵列在太阳能电池应用的有机材料的开发中被高度寻求以增强电子/激子传输，以及在可充电聚合物电池中高效地传输Li+离子。本项目的重点是测定共晶相图，以此来抑制和/或消除聚乙二醇二丙烯酸酯(PEGDA)/丁二腈(SCN)/双(三氟甲基磺酰)亚胺锂(LiTFSI)的二元和三元混合物中不需要的成分晶体。该体系的独特之处在于，PEGDA的光刻交联不仅提高了网络的机械强度和完整性，而且增加了离子在不受干扰的通道中的传输。此外，定向排列的通道结构还会增加SCN的界面面积和与氰基的络合作用，从而增加离子存储容量。另一个优点是，SCN可以有效地电离离子盐，并完全消除不需要的LiTFSI晶体。更重要的是，所制备的聚合物电解质膜是一种不需要有机溶剂的独立薄膜，在常温下具有很高的电导率(7.1×10-3 S/厘米)。制造的聚合物电解质膜可以在40-80℃的宽温度范围内运行-技术概述：该项目的目标是研究和开发用于“绿色”电动汽车的轻质和可充电的独立式聚合物锂离子电池。与传统的电解液电池不同，目前的聚合物电解质膜不含有毒或易燃的有机溶剂，因此可以避免溶剂泄漏或电池燃烧等安全问题。目前的聚合物电解质可以以任何形状或形式模塑，因此它应该会有更广泛的用途。沿薄膜厚度方向垂直排列柱状形貌的策略将进一步改善离子在通道中的传输，并由于表面/界面面积的增加而增强离子存储能力。这样获得的知识可以转移到当前项目范围之外，特别是用于开发太阳能电池的有机材料和信息技术中的光-光开关。这个项目将培养研究生和本科生，他们将接触到聚合物材料科学、工程数学和电化学方面的多学科研究。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项目向公众传播，阿克伦全球聚合物学院为高中科学教师及其学生举办研讨会。