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

在化学、生物工程、环境和运输系统部门的电化学系统项目的支持下，研究人员将开发创新的原位技术来表征可充电电池的液体电解质。可充电电池是电子产品、电动汽车和电网储能中最流行的储能设备之一。下一代可充电电池要求在快速充电和安全性方面表现优异。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质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课程，鼓励来自STEM中代表性不足群体的学生参与研究，并通过外展活动扩大研究的影响，例如与当地学校教师就K-12科学教育举行讲习班。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质的传输特性和微观结构，包括原位探针束偏转（PBD）、原位小角度x射线散射（SAXS）、欧姆显微镜和微电极阵列。具体来说，在浓溶液理论的框架下，原位PBD将用于测量转移数和扩散率。它只需要一个实验就可以确定电解质的转移数和扩散率，而传统的方法则需要三到四个电化学实验的结合。原位PBD还可以监测工作电池中电解质的离子浓度分布。原位SAXS将用于表征浓缩电解质的微观结构，并监测电场诱导的离子对和/或聚集体的变化。欧姆显微镜将用于测量电导率，并监测由强电场引起的电荷分离引起的电解质电导率的变化。微电极阵列将用于同时测量电解质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，将提供分子水平上的微观结构和输运性质之间关系的理解。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。

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.