Excellence in Research: Investigation of Interfacial Chemical and Ion Transport in Solid Inorganic-Polymer Electrolytes

对电化学系统中界面处的离子传输的有限理解是开发具有超高能量密度和高功率密度的安全、可靠的先进锂电池的主要障碍。 运输和可再生电力储存的广泛电气化需要这种电池。对复合电解质和电极之间的界面反应的离子传输和控制的基本理解将使包含更安全的固体聚合物基复合电解质的新界面的工程化成为可能。在这个项目中，研究人员将研究电解质/电极边界以及陶瓷/聚合物基质之间的离子传输。该团队将利用几种不同的表征工具来了解材料的特性。参与该研究项目的学生将从事前沿研究，研究对解决全球能源挑战具有重要意义的主题。该项目将通过招募和留住来自代表性不足的少数群体的高素质学生，并让这些学生参与储能技术的尖端研究和开发，来促进STEM（科学、技术、工程和数学）劳动力的多样性。路易斯安那州泽维尔大学（Xavier University of Louisiana）和圣母大学（University of Notre Dame）之间的整体合作，包括本科Xavier研究人员对ND研究小组的夏季访问，将增强学生的研究经验，促进STEM领域代表性不足的少数民族学生的保留，界面研究是设计新的固体电解质系统的关键，既具有高的体离子电导率，又在循环中对Li阳极化学和尺寸稳定。复合聚合物电解质具有承受电极体积随循环而变化所需的柔性，但在本体电解质中的陶瓷和聚合物之间以及复合材料和电极表面之间的离子传输受到限制。界面电阻导致降低的体离子电导率、降低的安全可实现的循环速率和差的Li阳极性能。在这个项目中，由Xepland和ND的研究人员，系统内的界面化学和离子传输，包括复合聚合物电解质和锂阳极，将作为聚合物类型的函数进行研究，以便从根本上理解每种化学和聚合物动力学对界面特性的影响。这些研究将测试以下假设：电解质和阳极之间以及陶瓷和聚合物基质之间的纳米级空隙形成导致用于离子传输的粗糙度和小接触面积，这增加了界面电阻，并且界面处的锂缺乏层导致空间电荷的形成，这也有助于界面电阻。该项目由激励竞争研究的既定计划（EPSCoR）和扩大参与工程计划共同资助。该奖项反映了NSF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。

Limited understanding ion transport at the interfaces in electrochemical systems is a major obstacle in the development of safe, reliable advanced lithium batteries with ultra-high energy density and high power-density. Such batteries are needed for the widespread electrification of transportation and storage of renewably generated electricity. Fundamental understanding of ion transport and control of interfacial reactions between a composite electrolyte and electrodes will enable engineering of new interfaces containing safer, solid polymer-based composite electrolytes. In this project, the researchers will investigate ion transport at the boundaries of the electrolyte/electrodes as well as between the ceramic/polymer matrix. The team will utilize several different characterization tools to understand the properties of the materials. The students involved in this research project will be engaged in cutting-edge research on a topic of importance to addressing the global energy challenge. This project will contribute to improving diversity in the STEM (Science, Technology, Engineering, and Mathematics) workforce by recruiting and retaining highly qualified students from underrepresented minority groups and engaging these students in cutting-edge research and development in energy storage technologies. The overall collaboration between Xavier University of Louisiana (XULA) and the University of Notre Dame (ND) which includes summer visits of undergraduate XULA researchers to the ND research group will enhance the students’ research experiences, promote retention of underrepresented minority students in STEM fields, and enable research not possible by either group individually.Interfacial research is critically needed for designing new solid electrolyte systems with both high bulk ionic conductivity and that is chemically and dimensionally stable against the Li anode with cycling. Composite polymer electrolytes have flexibility necessary to withstand electrode volume changes with cycling, yet ion transport is limited between the ceramic and polymer in the bulk electrolyte and between the composite and the electrode surface. The interfacial resistances lead to reduced bulk ionic conductivities, reduced safely achievable cycling rates, and poor Li anode performance. In this project by researchers at XULA and ND, the interfacial chemistry and ion transport within the system including composite polymer electrolytes and Li anodes will be investigated as a function of polymer type to allow for the fundamental understanding of each chemistry and polymer dynamics on interfacial properties. These studies will test the hypotheses that nanoscale void formation between the electrolyte and anode, as well as between ceramic and polymer matrix, causes roughness and small contact area for ion transport which increases the interfacial resistance, and a lithium deficient layer at the interface leads to the formation of space-charge which also contributes to interfacial resistance. This project is jointly funded by the Established Program to Stimulate Competitive Research (EPSCoR), and the Broadening Participation in Engineering Program.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.