Morphology and Mobility in Semi-Crystalline and Nanofilled Solid Polymer Electrolytes

技术概述：该项目涉及固体聚合物电解液[SPE]，这是一类有潜力用于锂离子电池的材料。其具体目标是制备粒子分散可控的纳米复合材料，确定共存晶相的纳米级形貌，并确定聚合物动力学与提高电导率之间的关系。纳米复合材料与固相萃取有关，因为它们已被证明可以将导电性提高到实际范围。然而，纳米颗粒增加SPE电导率的机制还不是很清楚。其中一个问题是颗粒的聚集，这在标准制备方法下是很重要的，并导致无法复制的样品和结果。该项目将应用最近报道的一项技术来控制聚合物混合物中相分离的长度范围。这种技术将聚合物包裹在纳米乳液中，然后蒸发聚合物相溶剂，通过使用表面活性剂将尺寸可控的聚合物纳米球悬浮在非溶剂中。将两种这样的制剂混合以形成混合物。目前的项目将用纳米颗粒取代其中一种聚合物，但其他情况下将遵循相同的程序。具有良好控制间距的纳米复合材料的生产将允许在可重复的条件下研究结晶、聚合物的流动性和导电性，从而提供了增强导电性的机制，以及对受限聚合物/盐络合物行为的基本了解。非技术概述：该项目旨在改善材料的性能，该材料有望用作便携式和其他设备中的柔性和轻质电池。所需的材料是固体塑料，随着纳米颗粒的加入，它在电池中的使用得到了改善。颗粒改善性能的原因尚不清楚，因为颗粒很难在塑料基质中分散。该项目将使用一种新的分散颗粒的方法，生产出特性良好的材料，这些材料可以用来获得所需的理解。这些材料将使用中子散射进行研究，中子散射是一种测量纳米尺度上结构的存在和运动的技术。美国最近在中子散射设施上投入了大量资金：例如，橡树岭国家实验室的散裂中子源。这些扩大的设施需要更多的调查人员来使用这些仪器。因此，针对中子散射未得到充分利用的科学领域的外联活动是该项目的一部分。

TECHNICAL SUMMARY: This project addresses solid polymer electrolytes [SPEs], a class of materials with the potential for use in lithium ion batteries. The specific aims are to produce nanocomposites with controllable particle dispersion, determine the nanoscale morphology of coexisting crystalline phases, and determine the relationship between polymer dynamics and increased conductivity. Nanocomposites are relevant to SPEs because they have been demonstrated to increase conductivity into the practical range. However, the mechanism by which nanoparticles increase conductivity in SPEs is not well understood. One of the problems is aggregation of the particles, which is significant using standard preparation methods and leads to irreproducible samples and results. The project will apply a technique recently reported for controlling the length scale of phase separation in a polymer blend. This technique encapsulates the polymers in a nano-emulsion, followed by evaporation of the polymer phase solvent, leaving a polymer nano-sphere with controllable size suspended in a non-solvent by use of a surfactant. Two such preparations are mixed to form the blend. The current project will replace one of the polymers with a nanoparticle, but otherwise follow the same procedure. Production of nanocomposites with well controlled spacing will allow for study of crystallization, polymer mobility and conductivity under reproducible conditions, thus providing a mechanism for enhanced conductivity, as well as fundamental understanding of the behavior of confined polymer/salt complexes.NON-TECHNICAL SUMMARY: This project seeks to improve the properties of a material with potential use as a flexible and lightweight battery in portable and other devices. The required material is a solid plastic, and its use in batteries improves with the addition of nanometer-sized particles. The reason the particles improve properties is not well understood, because dispersion of the particles in the plastic matrix is difficult. The project will use a new method for dispersion of the particles, producing well characterized materials that can be used to gain the needed understanding. The materials will be studied using neutron scattering, a technique measuring both existence and movement of structures over nanometer length scales. The US has recently invested significantly in neutron scattering facilities: for example the Spallation Neutron Source at Oakridge National Laboratories. These expanded facilities require additional investigators to use the instruments. Thus outreach activities targeted towards scientific areas where neutron scattering is under-utilized is a part of this project.