CAREER: In Situ Observation of Coupled Transport and Degradation in Battery Electrodes

PI姓名：纳尔逊提案ID：1454437交通运输占美国能源消耗的25%至30%。 电动汽车是减少运输化石燃料消耗的一种替代方案。 电动汽车需要平衡电能存储和电力输送需求的可充电电池，并且这些电池必须具有支持可负担的拥有成本的寿命。锂离子电池是目前电动汽车应用的领先技术。 锂离子电池功率和能量存储容量可以通过利用利用纳米技术原理在纳米级结构化的电池电极材料来增强。 然而，使用纳米结构电极可能会加速电极退化，从而缩短电池寿命。该研究奖旨在了解在现实条件下充电和放电过程中纳米结构锂离子电池电极的降解。 这将通过使用先进的X射线成像技术来实现，以可视化电池电极在操作过程中发生的情况，这是以前从未做过的。 从拟议的研究中获得的见解将导致电池材料结构，提高电池性能和可靠性。这些改进反过来又有可能延长混合动力和电动汽车的续航里程和寿命。 与该奖项相关的教育和推广计划将为机械工程本科生提供储能过程的实践经验。 该CAREER奖项的技术目标是通过电池充电和放电过程中的原位三维（3-D）X射线成像技术，对导致锂离子电池纳米结构尖晶石阴极降解的过程进行基本了解。 拟议的研究将测试以下假设：高功率锂离子电池的纳米结构阴极在高温下由于阴极活性材料的金属溶解增强而表现出加速降解。这一假设将通过制造具有有序和不规则微观结构的电极，表征在一定温度范围内的电极性能，以及使用X射线纳米断层扫描直接观察3-D微观结构来进行测试。 在这项研究计划的过程中，新的贡献，电化学能量转换和存储领域的预期。 这些贡献包括使用3-D X射线材料断层成像来帮助阐明电极微结构和降解机制之间的相互作用，揭示纳米结构电池架构的优点和挑战，以及生成一组记录的锂离子电池材料的3-D微结构数据，这些数据与电池性能和通过电化学测试降解有关。与此职业奖相关的教育和推广计划将为机械工程本科生提供储能过程的实践经验。 为本科生实验室开发的储能实验将进行调整，为服务于STEM领域代表性不足的群体的学校的K-12教师培训计划提供模块，并将支持在亚拉巴马亨茨维尔的美国空间和火箭中心开发展览，吸引不同的观众参与储能主题和概念。

PI Name: Nelson Proposal ID: 1454437 Transportation accounts for 25% to 30% of U.S. energy consumption. Electric vehicles are one alternative to reducing fossil fuel consumption for transportation. Electric vehicles require rechargeable batteries that balance the electrical energy storage and power delivery needs, and these batteries must have lifetimes that support affordable cost of ownership. The lithium-ion battery is currently the leading technology for electric vehicle applications. Lithium-ion battery power and energy storage capacity can be enhanced by utilizing battery electrode materials that are structured at the nanoscale using principles of nanotechnology. However, the use of nanostructured electrodes may accelerate electrode degradation that reduces battery life. This research award seeks to understand degradation in nanostructured lithium-ion battery electrodes during charging and discharging under realistic conditions. This will be accomplished by using advanced x-ray imaging techniques to visualize what happens to the battery electrode during operation, which has never been done before. Insights from the proposed research will lead to battery material structures that improve battery performance and reliability. These improvements in turn have potential to extend the range and lifetime of hybrid and electric vehicles. The education and outreach programs associated with this award will provide mechanical engineering undergraduate students with hands-on experiences in energy storage processes. The technical goal of this CAREER award is develop a fundamental understanding of the processes leading to degradation of nanostructured spinel cathodes for Li-ion batteries through in situ three-dimensional (3-D) X-ray imaging techniques during battery charge and discharge. The proposed research will test the hypothesis that nanostructured cathodes for high power lithium-ion batteries exhibit accelerated degradation at elevated temperature due to enhanced metal dissolution from the cathode active material. This hypothesis will be tested by fabricating electrodes with ordered and irregular microstructure, characterizing electrode performance over a range of temperatures, and directly observing 3-D microstructure using X-ray nanotomography. During the course of this research program, new contributions to the fields of electrochemical energy conversion and storage are expected. These contributions include the use of 3-D X-ray material tomatographic imaging to help elucidate the interactions between electrode microstructure and degradation mechanisms, revealing the merits and challenges of nanostructured battery architectures, and generation of a documented set of 3-D microstructural data for lithium-ion battery materials that is correlated to battery performance and degradation through electrochemical testing. The education and outreach programs associated with this CAREER award will provide mechanical engineering undergraduate students with hands-on experiences in energy storage processes. Energy storage experiments developed for undergraduate laboratories will be adapted to provide modules for K-12 teacher training programs in schools that serve under-represented groups in STEM fields, and will also support development of exhibits at the U.S. Space and Rocket Center in Huntsville, Alabama that engage diverse audiences with energy storage topics and concepts.