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

9972466马丁这个项目将发展在无序电解质中的电荷传输的基本新的理解。 对基于电化学的便携式能源（例如电池和燃料电池）的日益增加的依赖和性能要求将迅速超过由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将不得不将其离子电导率提高几个数量级以上，以跟上这些设备所需的不断增加的消耗速率。几年前，电池和燃料电池中固体电解质的离子电导率的这种增加是可能的，这一点没有受到质疑。 PI的新研究表明，情况可能并非如此。 他对化学优化的快离子传导（FIC）玻璃的研究表明，离子电导率的强非阿克里乌斯温度依赖性将离子电导率限制在低于预期值的100至1000倍。 这种现象将对当今市场上的众多基于电化学能量的设备具有巨大的设计影响，并且其数量正以指数速度增长。 在该项目中，将在更高的温度和更宽的频率范围内测量新银离子导体的电导率，以确定电导率是否达到饱和或最大值。 然后，新的锂离子导体将被测量，看看非阿克里乌斯电导率是否是普遍的。 宽频率范围的核自旋晶格弛豫速率（NSLR）和电导率的测量将结合起来，以确定是否可以使用一个温度无关的活化能分布，以适应温度和频率的NSLR和电导率的依赖性。 这样的拟合将是一个强有力的测试是否简单的激活过程理论描述的离子动力学或是否必须包括额外的动力学效应。 此外，还将建立包括强多体相互作用的电导率与温度和频率的关系的理论模型，将对从强相互作用状态到短时间弱相互作用状态的全时域响应进行非弹性中子散射和高频电导率研究，将建立原子级传导拓扑结构的分子动力学模拟，和弹性中子散射研究将进行探测玻璃结构在中程水平，其中网站连接是重要的。 该项目将涉及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。对用于如此多的消费产品中的基于电化学的便携式能源（例如电池和燃料电池）的日益增加的依赖和性能要求，要求越来越好的能源。该项目将提供电解质的化学性质与其性能之间的关系的理解，从而将使在纳米级的新电解质的离子电导率的数量级增加的设计。 PI已经建立了强大的研究团队，沿着国际合作，有望在这一领域取得进展。

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.***