CAREER: Probing and Exploiting Short-range Order in Crystalline Materials for Fast Ion Transport

该奖项全部或部分由《2021年美国救援计划法案》（公法117-2）资助。非技术总结：快离子导体是能源存储的主要参与者，是汽车电气化的关键战略领域，也是许多可再生能源（如太阳能和风能）间歇性和随机性的最佳解决方案。过去的研究主要集中在具有完美原型结构的离子导体上。因此，进一步的材料发现仅限于渐进式的改进和狭窄的化学范围。在该项目中，在材料研究部固态和材料化学项目的支持下，首席研究员研究了具有组成灵活性的结构无序离子导体，这可能会减轻该行业对任何单一关键金属来源的依赖，这些金属来源具有广泛的社会影响。该项目还整合了教育和研究，以增加STEM学生的入学率、多样性和保留率，创造美国未来的STEM劳动力。为了实现这些目标，PI为大学教学和K-12推广创建了示范工具包，一个带有实践研究活动的晶体生长课程，以及一个用于交互式晶体学教学的新型增强现实体验。PI与犹他州STEM行动中心合作，接触来自STEM中代表性不足的背景和历史上STEM表现不佳的学区的学生，并向他们提供工具包和演示。技术概述：晶体材料中离子的快速传输使各种设备（如电池、膜和燃料电池）具有关键功能。然而，这些材料的结构特性提出了一个突出的挑战。它们的晶体结构通常表现为短程有序，而传统的基于衍射的技术只对长周期特征敏感。因此，过去的研究要么因为缺乏仪器灵敏度而不得不忽略它，要么因为担心复杂性和不可预测性而完全避免它。这个CAREER项目由材料研究部固态和材料化学项目支持，通过在明智选择的离子导体上执行最先进的同步加速器和中子散射来克服这些困难，以精确地表征移动离子和框架子晶格中的这些细微结构。该项目还系统地修改了化学和合成变量，并将这些参数与结构观察和性能测量相关联，以揭示以前被忽视的结构-性能关系。这些见解使设计具有快速离子传输和卓越经济可持续性的破坏性新材料成为可能。PI还通过采取以研究为基础的实践活动为中心的方法，开展一系列教育和推广活动，以加强认知知识和保留，并激发学生对高等STEM教育和职业的兴趣。具体工作包括：(1)向初中和高中推广STEM活动工具包；(2)在晶体生长课程中拓展动手实验环节；(3)为交互式晶体学教学创建增强现实应用程序。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).Non-Technical Summary: Fast ion conductors are major players in energy storage, a strategically critical area for the holy grail of vehicle electrification and the best solution to the intermittent and random nature of many renewable energy sources, such as solar and wind. Past research has heavily focused on ion conductors with perfect prototype structures. As a result, further materials discovery was limited to incremental improvement and a narrow range of chemistry. In this project, with support from the Solid State and Materials Chemistry program in the Division of Materials Research, the principle investigator investigates structurally-disordered ion conductors with compositional flexibility that can potentially alleviate the industry’s reliance on any single critical metal source which has broad societal impact. The project also integrates education and research to increase enrollment, diversity, and retention of STEM students, creating America’s future STEM workforce. In pursuit of these goals, the PI creates demonstration kits for college teaching and K-12 outreach, a crystal growth course with hands-on research-based activities, and a novel augmented reality experience for interactive crystallography pedagogy. The PI collaborates with the Utah STEM Action Center to reach students from backgrounds underrepresented in STEM and school districts historically underperforming in STEM and deliver them the kits and demonstrations. Technical Summary: The facile transport of ions in crystalline materials enables key functionality in various devices, such as batteries, membranes, and fuel cells. The structural characterization of these materials, however, presents an outstanding challenge. Their crystal structures often exhibit short-range order, whereas traditional diffraction-based techniques are only sensitive to long-range periodic features. As a result, past research either had to ignore it for lack of instrument sensitivity or avoided it completely for fear of complexity and unpredictability. This CAREER project, supported by the Solid State and Materials Chemistry program in the Division of Materials Research, overcomes these difficulties by performing state-of-the-art synchrotron and neutron scattering on judiciously selected ion conductors, to precisely characterize these structural subtleties in both the mobile ion and the framework sublattices. The project also systematically modifies the chemistry and synthesis variables and correlate these parameters with structural observations and property measurements to reveal previously overlooked structure-property relationships. These insights enable the design of disruptively new materials with fast ion transport and excellent economic sustainability. The PI also engages in a series of education and outreach activities by taking an approach centering on research-based, hands-on activities, to reinforce cognitive knowledge and retention and stimulate students’ interest in higher STEM education and careers. Specific efforts include: (1) outreach to middle and high schools with STEM activity kits; (2) expansion of the hands-on lab sessions in a crystal growth course; and (3) creation of an augmented reality app for interactive crystallography pedagogy.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.