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

10366772 kotov寻找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过渡至关重要。锂金属聚合物电池和一些锂离子电池可以潜在地实现所需的电力存储参数，但必须解决所有锂电池技术的核心瓶颈，即与界面质量/电荷传输相关的基本问题，即枝晶的生长。它们是循环后性能迅速下降和严重的消防安全问题的根源。这导致了对离子导电膜（ICMs）防止枝晶生长的新概念的迫切需要。通过对ICM-电极边界输运过程的理论分析，从理论上证明了剪切模量为G′Ý7 GPa的ICM可以完全抑制枝晶的生长。目前，还没有材料可以满足这一要求和其他关键要求，如离子电导率Ý 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。知识优势：该项目将利用(1)层接层组装（LBL）和(2)超强凯夫拉纳米纤维来获得新一代能够完全抑制枝晶生长的icm。LBL是一种非常简单、廉价的技术，可使薄膜具有优异的均匀性和高杨氏模量。他们的机械性能将进一步提高与凯夫拉尔。这种聚合物将以一种非常规的形式用于纳米纤维分散体，其直径为50-70纳米，长度为1-3微米。基于令人鼓舞的初步结果，PIs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达到10-4-10-3 S/m范围内的离子电导率；(2)通过使用固有的强LBL组分并控制它们之间的界面交联，达到Ý 7 GPa。这两个目标本质上都与材料的界面和质量运输过程有关，在这方面，该小组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ICMs的方法，并且在树突形成方面没有成熟的专业研究人员。除了引入LBL技术作为制造ICMs的新方法外，固体材料中离子传输的便利化为电池和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源发电机。凯夫拉尔纳米纤维的使用代表了对这种成熟的柔性装甲材料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额外的智力影响，这在没有纳米级界面控制的icm中是很难实现的。更广泛的影响：拟议的工作朝着缓解二氧化碳中和（能源）经济道路上的技术瓶颈迈出了重要的一步。新型icm的开发可以通过为电动汽车提供具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，从而大大减少二氧化碳排放。中间储电块的安全性是大型电池的另一个基本挑战，这里也要解决这个问题。在开展研究工作的同时，还将积极传播有关新材料对能源研究重要性的信息。该项目的这一部分将在密歇根州安娜堡社区高中的高中生以及密歇根大学电气和计算机工程系的本科生的大力参与下完成，我们从2007年开始与他们建立关系。与他们一起，研究人员将开发一个网站，解释现在和将来发电和消费链的关键组成部分的原理。本科生和高中生的共同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，并将有助于将更多高素质的少数族裔和女性学生带入工程专业。

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.