Dynamics and Structure in Complex Disordered FIC Electolytes: Is There a Maximum Ionic Conductivity in the Solid State?

复杂无序 FIC 电解质的动力学和结构：固态中是否存在最大离子电导率？

• 批准号: 9972466
• 负责人: Steve Martin
• 金额: $ 49.44万
• 依托单位: Iowa State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-07-15 至 2004-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9972466&HistoricalAwards=false
• 关键词: Dynamics; Structure; Complex; Disordered; FIC

9972466MartinThis project will develop fundamental new understandings of charge transport in disordered electrolytes. The ever increasing dependence upon and the performance requirements of electrochemically-based portable energy sources, such as batteries and fuel cells, will rapidly outpace the current technological benchmarks being set by the core technologies of these devices. Battery and fuel cell electrolytes, for example, will have to increase their ionic conductivity by more than a couple of orders of magnitude to keep pace with the ever increasing drain rates required of these devices. That such increases in the ionic conductivities of the solid electrolytes in batteries and fuel cells are possible was not questioned a few years ago. New research by the PI has shown that such may not the be the case. His work on chemically optimized fast ion conducting (FIC) glasses has shown that a strong non-Arrhenius temperature dependence of the ionic conductivity limits the ionic conductivity to values 100 to 1000 times below that expected. This phenomenon will have tremendous design implications for the multitude of electrochemical-energy based devices that are on the marketplace today and whose numbers are growing at an exponential rate. In this project, the conductivity of new silver-ion conductors will be measured to higher temperatures and wider frequency ranges to determine if the conductivity reaches a saturating or maximum value. Then, new lithium-ion conductors will be measured to see if the non-Arrhenius conductivity is universal. Wide frequency range nuclear spin lattice relaxation rate (NSLR) and conductivity measurements will be combined to determine if a temperature independent distribution of activation energies can be used to fit the temperature and frequency dependence of both the NSLR and the conductivity. Such fitting will be a powerful test of whether simple activated process theory describes the ion dynamics or whether additional dynamical effects must be included. In addition, theoretical models of the temperature and frequency dependence of the conductivity that include strong many-body interactions will be developed, inelastic neutron scattering and high frequency conductivity studies of the full time-domain response from the strongly interacting regime into the short time weakly interacting regime will be performed, molecular dynamics simulations of the atomic-level conduction topologies will be developed, and elastic neutron scattering studies will be performed to probe glass structure at the intermediate range level where site connectivity is important. The project will involve graduate student research teams working with undergraduate and high school students in a strong collaboration with both US and international researchers as well as a domestic battery manufacturer. %%%The ever increasing dependence upon and the performance requirements of electrochemically-based portable energy sources, such as batteries and fuel cells, used in so many consumer products, demand better and better energy sources. This project will provide understanding of the relationships between the chemistry of the electrolyte and its performance and thus will enable design at the nano-scale of new electrolytes with order of magnitude increases in ionic conductivities. The strong research team the PI has built, along with the international collaborations, promise advances in this area.***

9972466Martin 该项目将对无序电解质中的电荷传输产生根本性的新理解。 对基于电化学的便携式能源（例如电池和燃料电池）的日益增长的依赖和性能要求将迅速超过这些设备的核心技术设定的当前技术基准。 例如，电池和燃料电池电解质必须将其离子电导率提高几个数量级以上，才能跟上这些设备所需不断增加的消耗率。几年前，人们并没有质疑电池和燃料电池中固体电解质离子电导率的这种增加是可能的。 PI 的新研究表明，情况可能并非如此。 他在化学优化的快离子传导 (FIC) 玻璃方面的工作表明，离子电导率的强烈非阿累尼乌斯温度依赖性将离子电导率限制为低于预期值 100 至 1000 倍。 这种现象将对当今市场上众多基于电化学能源的设备产生巨大的设计影响，这些设备的数量正在以指数速度增长。 在这个项目中，新型银离子导体的电导率将在更高的温度和更宽的频率范围内进行测量，以确定电导率是否达到饱和或最大值。 然后，将测量新的锂离子导体，看看非阿累尼乌斯电导率是否具有普遍性。 将宽频率范围核自旋晶格弛豫率 (NSLR) 和电导率测量相结合，以确定是否可以使用与温度无关的活化能分布来拟合 NSLR 和电导率的温度和频率依赖性。 这种拟合将有力地检验简单的活化过程理论是否描述了离子动力学，或者是否必须包括额外的动力学效应。 此外，将开发包括强多体相互作用的电导率的温度和频率依赖性的理论模型，将进行从强相互作用状态到短时弱相互作用状态的全时域响应的非弹性中子散射和高频电导率研究，将开发原子级传导拓扑的分子动力学模拟，并将进行弹性中子散射研究以探测玻璃结构 站点连接性很重要的中间范围级别。 该项目将由研究生研究团队与本科生和高中生合作，与美国和国际研究人员以及国内电池制造商密切合作。 %%%许多消费产品中使用的基于电化学的便携式能源（例如电池和燃料电池）对电池和燃料电池的依赖性和性能要求不断增加，因此需要越来越好的能源。该项目将让人们了解电解质的化学性质与其性能之间的关系，从而能够在纳米级设计新型电解质，离子电导率会增加一个数量级。 PI 建立的强大研究团队以及国际合作有望在这一领域取得进展。***