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

这项由材料研究部固态材料化学项目授予纽约州立大学石溪分校的续展奖项旨在了解电极材料和阴离子导体在操作条件下的功能。在这个项目中，格雷教授将建造、测试和利用一个核磁共振探测器，该探测器旨在获取功能正常和完好无损的锂离子电池的核磁共振谱。采用7Li和29Si磁角旋转核磁共振波谱以及X射线和中子散射的对分布函数分析相结合的方法，对处于亚稳态晶态的锂化硅负极材料进行了研究。第二个应用涉及对层状材料(如LixCoO2)的纳米颗粒的研究，以确定尺寸和形貌对充电时发生的各种相变的影响，以及带电材料在电解液中的稳定性。纳米颗粒正极材料有望在混合动力或电动汽车的高功率电池中得到应用。本研究的第二部分还将研究局部结构对钙钛矿(如LaGaO_3)和褐铁矿(如Ba2In_2O_5)等电极材料以及介于这些端数结构之间的中间体材料的长程阴离子电导的影响。B位的变温核磁共振谱(如71Ga，89Y核磁共振)将被用来确定阳离子的配位环境作为温度的函数，而17O核磁共振谱将被用来确定氧化物离子在电极材料不同局部环境中的迁移率。该计划所研究的材料将对设计用于锂离子电池和燃料电池的下一代材料具有重要的技术意义。使用硅作为锂离子电池的负极材料可能会有很大的商业利益。此外，该项目将为下一代能源、改进型电池和燃料电池材料的设计和开发提供基本的见解。在这个项目中工作的研究生、本科生和高中生，通过他们的研究和课堂经验，将接受复杂技术的培训，并欣赏这些技术用于解决重要的技术问题。

This renewal award to SUNY Stony Brook by the Solid State Materials Chemistry program in the Division of Materials Research is aimed at understanding how electrode materials and anionic conductors function under operating conditions. With this project, Professor Grey will be building, testing and utilizing a NMR probe designed to acquire NMR spectra of functioning and intact lithium-ion batteries. Lithiated silicon anode materials, which are in metastable crystalline phase, will be studied using a combination of in and ex-situ 7Li and 29Si Magic Angle Spinning Nuclear Magnetic Resonance (NMR) spectroscopy and pair distribution function analysis of x-ray and neutron scattering. A second application involves the investigation of nanoparticles of layered materials such as LixCoO2, to determine the effect that size and morphology have on the various phase transitions that occur on charging this material, and the stability of the charged materials in the electrolyte. Nanoparticulate cathode materials are expected to have applications in high power batteries in, for example, hybrid electric or electric vehicles. The role of local structures on long-range anionic conductivity of electrode materials such as perovskite (such as LaGaO3) and browmillerite (such as Ba2In2O5) along with materials that can be viewed as intermediates between these end-number structures will also be studied as the second part of this study. Variable temperature NMR spectroscopy (e.g., 71Ga, 89Y NMR) of the B sites will be used to determine the coordination environments of the cations as a function of temperature, while 17¬O NMR spectroscopy will be used to determine the mobility of the oxide ions in different local environments of the electrode materials.The materials investigated by this program will have significant technological relevance for the design of the next generation of materials for use in Lithium ion batteries and fuel cells. The use of silicon as an anode material for a Lithium ion batteries is likely to be of great commercial interest. In addition, the project will provide fundamental insight in the design and development of the next generation of materials for energy sources, improved batteries and fuel cells. Graduate, undergraduate and high students working in this project through their research and classroom experiences will be trained in sophisticated techniques with an appreciation to their use to solve important technical problems.