EAGER: Ion Transport Properties and Engineering of Interfaces of Layered Kevlar Assemblies for High Performance Lithium Battery Membranes

1036672 Kotov找到一种具有高容量和快速放电率的安全储能技术解决方案对于美国向碳中和经济和石油独立的过渡至关重要。对于Li金属聚合物电池和一些Li+离子电池，可以潜在地实现用于电存储的所需参数，但是必须解决与界面质量/电荷传输的基本问题相关的所有锂电池技术的中心瓶颈，即枝晶的生长。它们是快速降低循环性能和严重消防安全问题的根源。这导致人们迫切需要防止枝晶生长的离子传导膜（ICM）的新概念。通过对离子束-电极界面输运过程的理论分析，从理论上证明了剪切模量为G ≤ 7 GPa的离子束可以完全抑制枝晶生长。目前，还没有满足这一要求和其他关键要求的材料，如离子电导率≤ 10- 4 S/m。为了解决这一瓶颈，并赋予看似矛盾的材料特性，需要新的制造方法来设计界面工艺/性能，并实现电池材料的技术目标。智力优势：本项目将利用（1）逐层组装（LBL）和（2）超强Kevlar纳米纤维，获得新一代可完全抑制枝晶生长的ICM。LBL是一种非常简单、廉价的技术，可生产出具有优异均匀性和高杨氏模量的薄膜。其机械性能将进一步增强与凯夫拉。这种聚合物将以非常规形式作为纳米纤维分散体使用，直径为50-70 nm，长度为1-3微米。基于令人鼓舞的初步结果，PI计划实现概念验证。 目标是：（1）利用离子导电聚合物的离子模板，使其离子电导率达到10-4 ~ 10- 3S/m;（2）利用固有的强LBL组分和控制它们之间的界面交联，使其达到~ 7 GPa。这两个目标本质上都与材料的界面和质量传输过程有关，而该集团在这方面拥有广泛的专业知识和技术能力。这是一种从根本上创新的制造离子传导材料的方法，并且没有建立具有枝晶形成专业知识的研究人员库。除了引入LBL技术作为制造ICM的新方法之外，促进固体材料中的离子传输为电池以及其他能量转换技术的发展提供了独特的机会。这些技术还包括燃料电池和渗透能发电机。凯夫拉纳米纤维的利用代表了这种成熟的柔性装甲材料的潜在用途的传统观点的巨大变化。锂离子模板工艺的发展也有望带来更多的知识影响，而在没有纳米尺度控制ICMs中的界面之前，这将很难实现。更广泛的影响：拟议的工作朝着缓解CO2中性（能源）经济道路上的技术瓶颈迈出了重要一步。新型ICM的开发可以通过为电动汽车提供有竞争力的全电动选择以及为太阳能和风力发电场提供高容量电力存储系统来大大减少二氧化碳排放。中间电存储块的安全性是大规模电池的另一个基本挑战，这里也要解决。研究工作将伴随着积极传播有关新材料对能源研究重要性的信息。项目的这一部分将由来自密歇根州安阿伯社区高中的高中生和密歇根大学电气与计算机工程系的本科生积极参与。调查人员将与他们一起开发一个网站，解释现在和未来发电和消费链关键组成部分的原理。本科生和高中生的联合工作预计将对高年级学生的载体选择产生强烈的积极影响，并将有助于使更多的高素质的代表性不足的少数民族和女生工程。

1036672KotovFinding a technological solution for safe energy storage with high capacity and fast discharge rates is vital for the transition to the carbon neutral economy and oil independence in the USA. The required parameters for electricity storage can potentially be achieved for Li metal polymer batteries and some Li+ ion batteries, but one must resolve the central bottleneck of all lithium battery technologies related to the fundamental problems of interfacial mass/charge transport, i.e. the growth of dendrites. They are the source of rapid decrease the performance upon cycling and serious fire safety concerns. This leads to the acute need of new concepts in ion-conducting membranes (ICMs) preventing dendrite growth. Based on theoretical analysis of transport processes at the ICM-electrode boundary, it was theoretically established that dendrite growth can be inhibited entirely by an ICM with a shear modulus of G ¡Ý7 GPa. Presently, there are no materials available satisfying this and other key requirements, such as ionic conductivity ¡Ý 10- 4 S/m. To resolve this bottleneck and to impart seemingly contradictive material characteristics, new manufacturing methods are needed to engineer interfacial processes/properties and achieve the technological targets for battery materials.Intellectual Merit: This project will utilize (1) layer-by-layer assembly (LBL) and (2) ultrastrong Kevlar nanofibers to obtain a new generation of ICMs that can completely suppress dendrite growth. LBL is very simple inexpensive technique leading to films with exceptional uniformity and high Young¡¯s modulus. Their mechanical properties will be further enhanced with Kevlar. This polymer will be used in an unconventional form as nanofibers dispersion with a diameter of 50-70 nm and a length of 1-3 microns.Based on encouraging preliminary results, the PIs plan to achieve proof-of-concept. The Objectives are: (1) to reach ion-conductivity in 10-4-10-3 S/m range using ion templating of ion-conducting polymers; and (2) to attainG¡Ý 7 GPa by using inherently strong LBL components and controlled interfacial cross-linking between them. Both of these objectives are intrinsically related to the interfacial and mass transport processes of the materials, where the group has extensive expertise and technical capabilities. This is a fundamentally innovative method for manufacturing of ICMs and does not have an established pool of researchers with expertise in dendrite formation. Besides the introduction of LBL technique as a novel method for manufacturing the ICMs, facilitation of ion transport in solid materials provides unique opportunities for the development of batteries as well as other energy conversion technologies. Such technologies also include fuel cells and osmotic energy generators. The utilization of nanoscale fibers of Kevlar represents a great change from the traditional view of potential uses of this well-established flexible armor material. Additional intellectual impact is also expected from the development of lithium ion-templating process which would be difficult to realize before without nanoscale control of interfaces in ICMs.Broader Impact: The proposed work makes a significant step toward alleviating the technological bottlenecks on the way to CO2¨Cneutral (energy) economy. The development of new ICMs can greatly reduce CO2 emissions by making possible competitive full electric options for electrical vehicles and high capacity electrical storage systems for solar energy and wind farms. Safety of intermediate electrical storage blocks is another fundamental challenges for large scale batteries which is being addressed here as well. The research work will be accompanied by aggressive dissemination of information about importance of new materials for energy research. This part of the project will be done with strong involvement of the high school students from Community High School in Ann Arbor, MI with whom we have established relationships from 2007, and undergraduates from the UM Department of Electrical and Computer Engineering. Together with them, the investigators will develop a web-site explaining the principles of key components of the chain of electricity generation and consumption now and in the future. The joint work of undergraduates and high school students is expected to have a strong positive impact on the carrier choices of upper classmen and will help bringing greater number of highly qualified underrepresented minority and female students to engineering.