Collaborative Research: Characterization of Transport Properties and Microstructures of Battery Electrolytes via In Situ Spectroscopy

在化学、生物工程、环境和运输系统部电化学系统计划的支持下，研究人员将开发创新的现场技术来表征充电电池的液体电解液。充电电池是电子产品、电动汽车和电网储能最常用的储能设备之一。下一代充电电池要求在快速充电和安全方面具有优异的性能。这项工作将提供通用的方法来表征对电池性能至关重要的电解液的传输特性和微观结构。研究人员将把电池研究纳入本科生和研究生的教学大纲，鼓励STEM中代表性不足的学生参与研究，并通过外展活动扩大研究的影响，例如与当地学校教师举办关于K-12科学教育的研讨会。这项工作的主要目标是开发各种通用的原位技术来表征电池电解液的传输特性和微观结构，包括原位探针束偏转(PBD)、原位小角X射线散射(SAXS)、欧姆显微镜和微电极阵列。具体地说，在浓溶液理论的框架下，将使用原位PBD来测量迁移数和扩散系数。它只需要一次实验就可以确定电解液的迁移数和扩散系数，而传统的方法需要结合三到四个电化学实验。现场PBD还可以监测运行中电池中电解液的离子浓度分布。原位SAXS将用于表征浓缩电解液的微观结构，并监测电场诱导的离子对和/或聚集体的变化。欧姆显微镜将被用来测量电导率和监测强电场引起的电荷分离引起的电解液电导率的变化。微电极阵列将用于同时测量电解液的离子浓度和扩散系数。其他补充技术，包括拉曼光谱和分子动力学模拟，将在分子水平上了解微结构和传输特性之间的相关性。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

With the support from the Electrochemical Systems program in the Division of Chemical, Bioengineering, Environmental, and Transport Systems, the investigators will develop innovative in situ techniques to characterize the liquid electrolyte for rechargeable batteries. Rechargeable batteries are one of the most popular energy storage devices for electronic products, electric vehicles, and grid energy storage. The next generation of rechargeable batteries requires excellent performance in terms of fast charging and safety. This work will provide universal methods to characterize the transport property and microstructure of the electrolyte crucial to battery performance. The investigators will incorporate the battery research into their teaching curricula for undergraduate and graduate students, encourage students from underrepresented groups in STEM to participate in the research, and broaden the impact of the research through outreach activities, e.g., workshops with local school teachers on K-12 science education.The primary objectives of this work are to develop a variety of universal in situ techniques to characterize the transport property and microstructure of battery electrolytes, including in situ probe beam deflection (PBD), in situ small-angle X-ray scattering (SAXS), ohmic microscopy, and microelectrode array. Specifically, in situ PBD will be employed to measure the transference number and diffusivity in the framework of concentrated solution theory. It only requires one experiment to determine the transference number and diffusivity of the electrolyte, while traditional methods will require the combination of three or four electrochemical experiments. In situ PBD can also monitor the ionic concentration profile of the electrolyte in an operating battery. In situ SAXS will be used to characterize the microscopic structure of the concentrated electrolyte and monitor the variation of ion pairs and/or aggregates induced by the electric field. Ohmic Microscopy will be utilized to measure the conductivity and monitor the variation of electrolyte conductivity resulting from the charge separation induced by the strong electric field. A microelectrode array will be used to measure the ionic concentration and diffusivity of the electrolyte simultaneously. The other complementary techniques, including Raman spectroscopy and molecular dynamics simulation, will provide a molecular-level understanding of the correlation between the microstructure and transport property.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.