CAREER: Illuminating structure-property relationships in energy storage materials via quantitative light microscopy

非技术总结。可再生能源产能正在增加，预计将在本世纪满足全球能源需求。因此，现有技术将确保产生清洁的可再生能源。但是，储存和快速运送这些丰富的供应仍然是一个关键的未解决的挑战。对于全球向低碳或零碳能源经济转型而言，开发能够储存大量电荷并按需快速输送的新材料至关重要。该职业奖项目由材料研究部固态和材料化学项目支持，重点研究基础材料化学，以推进安全、快速充电和持久锂离子电池材料的设计原则。研究的重点是将材料的化学和结构特性与其导电锂离子的能力联系起来。快速锂离子传输对于造福社会的高功率应用是必要的，例如电动汽车，电动工具和便携式电子设备。PI Sambur的团队通过开发新的成像工具来揭示锂离子在纳米尺度上的运动，从而对锂离子的传输有了新的认识。这些微观测量使研究人员能够在材料化学和关键储能性能指标之间建立牢固的联系。通过这个项目，PI促进了显微镜教育，并增加了小学、高中、本科和研究生阶段学生使用显微镜工具的机会。成像是所有科学学科的基本技能，但很少有机会让学生接受显微镜教育。一个问题是，大学化学系和K-12学校缺乏显微镜工具来教育大量学生。PI计划开发低成本显微镜，为不同年龄组量身定制体验式学习活动，以满足这一关键需求。这项努力旨在向初中生和高中生推广科学，特别是科罗拉多州STEM教育管道中代表性不足的女性和西班牙裔/拉丁裔学生。技术总结。全球可再生能源经济的主要科学障碍是储能材料不足。对新型电池材料的详尽研究表明，未来的创新将源于基本的材料设计原则，这些原则不受电极制造中固有的艺术元素的影响。单粒子测量可以通过将已知的固态化学原理与决定电荷存储容量和速率的基本离子/电子传输过程联系起来，而不是依赖于混合和测量经验主义，从而建立材料设计原则。然而，这样的单粒子研究往往是缓慢而乏味的。该提案推进了高通量单粒子级光学显微镜和光谱学，结合电子，x射线和原子探针断层扫描技术，在晶体结构修饰，电子结构和电化学性能之间建立了新的联系。这项研究的重点是Wadsley-Roth晶体剪切结构，这种结构在块状（微米）材料中表现出非常快的锂离子扩散系数，表明这些复杂氧化物中的内置结构基元是解开调节离子扩散率的关键设计原则的关键。PI团队的目标是定义锂离子扩散率如何与化学、化学计量学和Wadsley-Roth化合物的块大小相关联。显微镜工具用于揭示表面表面和Wadsley缺陷的类型、浓度和排列如何影响电化学性能。本文创新的方法将普遍适用于广泛的现有材料和尚未发现的材料。本研究揭示的结构/性能关系的预期重大成果将是用于锂离子电池的安全、高倍率阳极材料的设计原则。PI决心通过开发低成本显微镜和旨在教育6 -12年级学生绘制现实世界系统（如太阳能电池）功能特性的活动，确保该研究项目的知识基础对社会产生广泛影响。这些活动引导学生掌握与年级相适应的实用知识，了解业余级太阳能电池的能量转换效率与材料异质性之间的关系。PI与科罗拉多州立大学自然科学教育推广中心的STEM专家密切合作，向科罗拉多州的初中和高中科学实验室分发工具包，补充现有的大学推广计划。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。

NON-TECHNICAL SUMMARY.Renewable energy capacity is increasing and expected to meet global energy demand this century. Existing technology will thus ensure the generation of clean, renewable energy. But the storage and rapid delivery of this abundant supply remains a critical unmet challenge. Development of new materials that store large quantities of charge and rapidly deliver it on demand is vital to any global transition to a low- or zero-carbon energy economy. This CAREER award project, supported by the Solid State and Materials Chemistry program in the Division of Materials Research, focuses on the study of fundamental materials chemistry to advance design principles for safe, fast-charging, and long-lasting Li-ion battery materials. The research focuses on linking chemical and structural properties of materials with their ability to conduct Li-ions. Fast Li-ion transport is necessary for high power applications that benefit society such as electric vehicles, power tools, and portable electronic devices. PI Sambur’s team gains new insight into Li-ion transport by developing new imaging tools that reveal Li-ion motion at the nanoscale. These microscopic measurements enable the researchers to make strong connections between materials chemistry and critical energy storage performance metrics. Through this project, the PI promotes microscopy education and increase accessibility to microscopy tools among elementary, high school, undergraduate, and graduate-level students. Imaging is an essential skill in all scientific disciplines, but there are few opportunities for students to receive an education in microscopy. One issue is that university chemistry departments and K-12 schools lack microscopy tools to educate large numbers of students. The PI plans to develop low-cost microscopes with experiential learning activities tailored to different age groups to address this critical need. This effort aims to promote science to middle and high school students, particularly underrepresented women and Hispanic/Latinx students in the Colorado STEM education pipeline.TECHNICAL SUMMARY.The major scientific roadblock to a global renewable energy economy is inadequate energy storage materials. Exhaustive research into new battery materials has made clear that future innovation will stem from fundamental materials design principles that are free from the element of art inherent in the fabrication of electrodes. Rather than relying on mix and measure empiricism, single particle measurements can establish materials design principles by linking known solid state chemistry principles to fundamental ion/electron transport processes that determine charge storage capacity and rate. However, such single particle studies are often slow and tedious. This proposal advances high-throughput single particle-level light microscopy and spectroscopy, in conjunction with electron, X-ray, and atom probe tomography techniques, to forge new links between crystal structure modifications, electronic structure, and electrochemical properties. The research focuses on Wadsley-Roth crystallographic shear structures that exhibit extraordinarily fast Li-ion diffusion coefficients in bulk-like (micron) material, signaling that the built-in structural motifs in these complex oxides are the key to unlocking critical design principles for tuning ionic diffusivity. The PI’s team aims to define how Li-ion diffusivity scales with the chemistry, stoichiometry, and block size of Wadsley-Roth compounds. The microscopy tools are used to reveal how the type, concentration, and arrangement of surface facets and Wadsley defects influences electrochemical properties. The methodologies innovated herein will be generally applicable to a wide range of existing materials and those that have yet to be discovered. An expected significant outcome from the structure/property relationships uncovered in this research will be design principles for a safe, high-rate anode material for use in Li-ion batteries. The PI is determined to ensure that the intellectual foundation of this research project has a broad impact on society through the development of low-cost microscopes and activities designed to educate 6th-12th grade students in mapping the functional properties of real-world systems such as solar cells. The activities guide students into a grade-appropriate, working knowledge about how the energy conversion efficiency of hobby-grade solar cells correlates with materials heterogeneity. The PI works closely with STEM experts in Colorado State University’s Natural Science Education Outreach Center to disseminate the kits to middle and high school science labs across Colorado, complementing existing University outreach programs.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.