An integrated study of ion dynamics and population distributions to understand the molecular underpinnings of charge transport through self-assembled solid polymer electrolytes

间歇性可再生能源发电和电动汽车的广泛采用可以通过获得可靠的锂基能源存储来加速。这些技术的突破性进展面临着来自基础知识差距的挑战，这些差距限制了电池的功率密度和耐用性。这两种性能属性都受到将用于这些电池的类固体离子导体内电荷传输性质的影响。更好地了解这些过程将有利于广泛的技术和商业前景领域，而不仅仅是可持续电网负载平衡和运输。具体的附加示例包括可展开传感器，气体分离，致动器，离子交换膜和光电子器件。本研究将侧重于了解离子通过纳米结构聚合物基质扩散的基本方面，并利用这些见解指导高功率密度锂离子电池固体聚合物电解质的设计。作为教育推广活动的一部分，主要研究者将参加学术克拉克卓越计划，ACE。这项工作的重点是准备和指导进入一年级的学生，特别是那些在STEM领域代表性不足的学生，以便他们能够充分利用科学领域的研究机会，并成功地满足当今科学职业或化学研究生学习的要求。pi组织了一系列的活动和实践，旨在指导和指导研究生在求职、知识产权法和科学写作方面的最佳实践。该项目的目标是研究纳米结构聚合物离子导体内锂离子（Li+）的动力学和种群分布，以了解控制电荷通过具有固体状机械性能和液体状离子扩散的基质的机制。该项目的二维核磁共振弛豫相关实验用于研究各种离子导体，以更全面地了解控制离子在聚合物中扩散的动态过程。该研究计划旨在使用锂导电的聚（乙烯-亚胺）基二嵌段共聚物作为模型系统，研究离子通过含有“离子渗透”但机械增强的机械坚固膜的传输。由于通过聚合物基质的大多数离子传导过程的动力学是由相同的基本原理控制的，因此这项工作的结果将影响各种离子传输介质的设计。本研究计划将量化聚合物骨架结构和介电常数对载流子有效浓度及其在纳米聚合物基体中的迁移率的影响。目标共聚物将作为载离子二嵌段共聚物基本相行为的模型化合物。本研究得出的结构-性能关系将有助于指导各种应用的新型离子导电元件的设计，例如锂离子电池、无水聚合物电解质膜燃料电池（PEMFC）、非水氧化还原液流电池、染料敏化太阳能电池等。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The widespread adoption of intermittent renewable-produced electricity and electric vehicles can be accelerated by access to reliable lithium-based energy storage. Disruptive advances in these technologies face challenges stemming from fundamental knowledge gaps that limit power density and durability in the batteries. Both performance attributes are impacted by the nature of charge transport within solid-like ionic conductors that would be used in these batteries. A better understanding of these processes will benefit a wide range of technologically and commercially promising areas beyond sustainable electrical grid load-balancing and transportation. Specific additional examples include deployable sensors, gas separation, actuators, ion exchange membranes, and optoelectronic devices. This study will focus on understanding the fundamental aspects of ion diffusion through nanostructured polymeric matrices, and on using these insights to guide the design of solid polymer electrolytes for high power density lithium-ion batteries. As part of education outreach activities, the Principle Investigators will participate in the Academic Clark Excellence, program, ACE. This effort focuses on preparing and mentoring entering first-year students, especially those underrepresented in STEM, so that they can take full advantage of the research opportunities available in the sciences and can successfully fulfill the requirements of today's science careers or post-graduate studies in chemistry. The PIs have structured a series of activities and practices seeking to guide and mentor graduate students on job-seeking best practices, intellectual property law, and scientific writing.The goal of this project is to examine the lithium-ion (Li+) dynamics and population distribution within nanostructured polymeric ionic conductors to understand the mechanisms controlling charge transport through matrices with solid-like mechanical properties and liquid-like ion diffusion. The two-dimensional nuclear magnetic resonance (NMR) relaxation correlation experiments of the project are used to study a wide variety of ion conductors in an effort to achieve a more complete understanding of the dynamic processes controlling ion diffusion through polymers. This research plan aims to use lithium-conducting, poly(ethylene-imine)-based, diblock copolymers as a model system to study ion transport through mechanically robust membranes containing "ion-permeable", yet mechanically reinforcing, domains. Since the dynamics of most ion conducting processes through polymer matrices are governed by the same fundamental principles, the results of this work will impact the design of a wide variety of ion-transporting media. This research plan will quantify the effect of polymer backbone structure and dielectric constant on the effective concentration of charge carriers and their mobility through a nanostructured polymeric matrix. The target copolymers will serve as model compounds for fundamental phase behavior ion-bearing diblock copolymers. The structure-property relationships derived from this study will help guide the design of new ion conducting components for a variety of applications, such as lithium-ion batteries, water-free polymer electrolyte membrane fuel cells (PEMFC), non-aqueous redox flow batteries, dye sensitized solar cells, as examples.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.