Solid State NMR Studies of Disordered Solids: Ionic Conductors and Battery Materials

无序固体的固态核磁共振研究：离子导体和电池材料

• 批准号: 0506120
• 负责人: Clare Grey
• 金额: --
• 依托单位: SUNY at Stony Brook
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0506120&HistoricalAwards=false
• 关键词: Solid; State; NMR; Studies; Disordered

TECHNICAL EXPLANATION New solid-state electrolytes with higher ionic conductivities are required in order to lower the operating temperatures of a solid oxide fuel cell (SOFC). In this research project, two phenomena that limit ionic conductivity at low temperatures or that may help in the design of materials with very high conductivities at moderate temperatures will be investigated. Specifically, solid-state NMR spectroscopy will be used to (i) investigate structure and ionic mobility at the interfaces between two phases (e.g., heterolayers formed of CaF2 and BaF2) or at the surfaces of nanoparticles, and (ii) identify the cation sites that are nearby the oxygen-ion vacancies in the moderate oxygen-ion conductor, doped lanthanum gallate (La0.9Sr0.1Ga0.9Mg0.1O3), in order to explore effects arising from trapped vacancy-dopant clusters formed due to magnesium (Mg2+) and strontium (Sr2+) doping. Fluorine-19 (19F) and oxygen-17 (17O) NMR will be used to investigate local structure and mobility; the local environments surrounding the cations will be probed by using gallium-71 (71Ga) and magnesium-25 (25Mg) magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy. Finally, MAS NMR methods will be used to study a series of battery electrode materials and related compounds. Many of these materials show metallic behavior and one aim of the work is to develop straightforward approaches for extracting structural/electronic information from the NMR spectra of these compounds. The research program will be incorporated into outreach activities involving both high and middle school students, undergraduates and the community at large. The P.I. runs a high-school program for minority students, which focuses on power sources, where the students synthesize battery electrodes (e.g., lithium manganese) and test their own batteries. NON-TECHNICAL EXPLANATIONImproved batteries and fuel cells with higher power densities are critically needed to help facilitate the move from an oil-based economy, to an economy based on a more diverse range of energy sources. New materials are required which will allow rapid transport of oxygen ions through a solid in order to lower the operating temperatures of a solid oxide fuel cell (SOFC), and reduce the costs of these devices. The aim of the first part of this research program is to identify, via the use of solid-state NMR methods, phenomena that limit conductivity of oxygen ions in membranes and at the interfaces between two different materials. Solid-state NMR methods allow the ions that move in a solid to be observed directly, and their mobility to be measured. The results from this program will help in the design of improved fuel cells and other devices where oxygen conduction is important (e.g., oxygen/nitrogen separations and oxygen sensors). In the second part of the research program, NMR methods will be used to study a series of battery electrode materials and related compounds in order to understand how these materials function. The research program will be incorporated into outreach activities involving both high school and middle school students, undergraduates and the community at large. The P.I. runs a high-school program for minority students, which focuses on power sources, where the students make and test their own batteries.

为了降低固体氧化物燃料电池（SOFC）的工作温度，需要具有较高离子电导率的新型固态电解质。在该研究项目中，将研究两个现象，这些现象将在低温下限制离子电导率，或者可能有助于研究中等温度下电导率很高的材料。 具体而言，固态NMR光谱法将用于（i）在两个相之间的界面（例如，由Caf2和Baf2形成的杂层）或纳米颗粒的表面上研究结构和离子迁移率，以及（II）识别阳离子位点位于中等氧气导体中的氧气空位附近，掺杂型腺体足酸盐（LA0.9SR0.1GA0.9MG0.1O3），以探索由于镁（MG2+）而形成的被困的空位掺杂簇引起的效果（MG2+）和锶（SR2+）掺杂。 Fluorine-19（19F）和Oxygen-17（17O）NMR将用于研究局部结构和迁移率；阳离子周围的局部环境将通过使用镀锌-71（71GA）和镁-25（25mg）魔术角旋转（MAS）核磁共振（NMR）光谱探测。 最后，MAS NMR方法将用于研究一系列电池电极材料和相关化合物。 这些材料中的许多表明金属行为，而工作的目的之一是开发直接的方法来从这些化合物的NMR光谱中提取结构/电子信息。 该研究计划将纳入涉及高中和中学生，本科生和整个社区的外展活动中。 P.I.为少数族裔学生开展了一项高中计划，该计划的重点是电源，在该电源源中，学生合成电池电极（例如锂锰）并测试自己的电池。 非常需要进行非技术解释性改良的电池和具有较高功率的燃料电池，以帮助促进从石油经济体转移到基于多种能源范围的经济体。 需要新材料，这将使氧离子通过固体快速运输，以降低固体氧化物燃料电池（SOFC）的工作温度，并降低这些设备的成本。 该研究计划的第一部分的目的是通过使用固态NMR方法，限制膜中氧离子电导率的现象以及两种不同材料之间的接口。固态NMR方法允许直接观察到固体移动的离子，并可以测量其迁移率。 该程序的结果将有助于设计改进的燃料电池和氧气传导很重要的设备（例如，氧/氮的分离和氧气传感器）。在研究计划的第二部分中，NMR方法将用于研究一系列电池电极材料和相关化合物，以了解这些材料的功能。 该研究计划将纳入涉及高中和中学生，本科生和整个社区的外展活动中。 P.I.为少数族裔学生开展一项高中计划，该计划的重点是学生制作和测试自己的电池的电源。