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：该项目的主要目标是（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便制造提供指导，以及（2）阐明创建周期性阵列的控制原理离子通道通过光刻垂直排列，并具有明确的域尺寸和周期性。这些由光聚合引起的相分离产生的排列通道不仅可以用作离子导线（或微通道），而且可以在不牺牲独立式电池膜的机械强度和完整性的情况下增加离子浓度。这种具有垂直方向的周期性通道阵列在太阳能电池应用有机材料的开发中增强电子/激子传输以及在可充电聚合物电池中高效Li+离子传输方面受到高度重视。该项目的重点是测定共晶相图，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）亚胺锂（LiTFSI）二元和三元混合物中不良成分晶体的手段）。 本系统的独特性在于，PEGDA 的光刻交联不仅提高了网络的机械强度和完整性，而且还增加了通过未受干扰通道的离子传输。此外，由于界面面积的增加以及与SCN的腈基团的络合，定向通道结构还将增加离子存储容量。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独立的薄膜，不需要有机溶剂，并且在环境温度下具有高电导率（7.1x10-3 S/cm）。所制造的聚合物电解质膜可以在 40-80 摄氏度的宽温度范围内运行。 非技术摘要：该项目的目标是研究和开发用于“绿色”的轻质可充电独立式聚合物锂离子电池电动汽车。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等安全问题。 本发明的聚合物电解质可模制成任何形状或形式，因此其应具有更广泛的用途。 圆柱状形态沿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转移到当前项目的范围之外，特别是用于太阳能电池有机材料的开发和信息技术中的光光转换。该项目将培养研究生和本科生，让他们接触高分子材料科学、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项目向公众传播，该学院为高中科学教师及其学生举办研讨会。