CAREER: Atomic-Scale Origins of Fast Ion Conduction through Complex Solid-State Electrochemical Interfaces

NON-TECHNICAL DESCRIPTION: Ceramic materials are essential for energy technologies. Specifically, the next-generation solid-state batteries using ceramics as a medium to conduct ions between positive and negative electrodes can improve the safety and energy density over today’s conventional liquid-based lithium-ion battery technology. However, the ability of ion transport in ceramics is not high enough to make batteries charge faster for use in electric vehicles and high-power applications. To solve this critical issue, this project aims to study how the material’s structures and interfaces affect the ion conduction under complex electrochemical conditions. Advanced electron microscopy techniques are used to visualize these fundamental processes on the nanometer scale. This is important because the obtained scientific knowledge can be used as design rules to guide the development of viable energy storage technologies, enhancing the energy security and sustainability. This project provides training on microscopy and analytical tools for students at all levels and promotes workforce development. The education and outreach program designed “for understanding nanotechnology and materials experience (FunMe)” offers summer research interns and extracurricular activities for undergraduate and K-12 students by leveraging programs partnered with local and nationwide initiatives. TECHNICAL DETAILS: Solid-state electrolytes with high ionic conductivity and interfacial stability are vital and urgently needed to enable safe and high-performance all-solid-state batteries for the next generation energy storage technology. This CAREER project aims to fundamentally understand the atomic-scale origin of fast lithium-ion conduction through complex electrochemical interfaces of ceramic solid-state electrolytes. Specifically, the effects of grain boundary microstructure, compositional heterogeneity, and space charge induced electrostatic potential on the ionic conductivity as well as the correlated electro-chemo-mechanical interface degradation mechanism will be elucidated using in situ transmission electron microscopy integrated with operando electrochemical impedance spectroscopy under air-free environments. The gained new knowledge will provide design principles for microstructural optimization and interfacial engineering to improve the cell performance and stability. This research will have multifaceted impacts on the advancements of fundamental theories, microscopy methodologies, and technically viable all-solid-state batteries for energy-intensive applications. The integrated education and outreach program offers a unique microscopy-centric STEM pipeline to engage graduate, undergraduate, and K-12 students, and support their career development and work readiness through interrelated teaching, mentoring, training, and outreach activities. 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.