Using Cryo-Electron Microscopy to Study Batteries
Interfaces and surfaces play a special role in synthesizing novel materials, enabling chemical reactions, designing electronic devices, and determining the mechanical stability of structural materials. While much progress has been made in the study of free surfaces, less is known about internal interfaces, especially between materials and liquids.
With this CAREER award, Lena F. Kourkoutis, Applied and Engineering Physics, is working to understand processes at interfaces between dissimilar materials—processes that determine how batteries function and how they fail. She and her team are pursuing this goal by developing and applying cryo-electron microscopy techniques that allow not only solid-solid but also liquid-solid and soft-hard interfaces to be studied at the nanometer to atomic scale.
Liquid-solid interfaces have yet to be imaged at high spatial resolution but play a critical role in a range of biological, chemical, and physical processes from catalysis to electrochemical energy storage to the formation of biominerals. Inspired by electron microscopy of biological systems, Kourkoutis is using rapid freezing to stabilize the soft and liquid components of composite systems in a vitreous state, enabling structural and spectroscopic studies by cryo-STEM. She and her team are able to image both thin materials, such as nanostructured electrode materials in liquid electrolytes, and thicker samples including lithium-metal batteries. One main focus is imaging the early stages of dendrite formation at lithium-metal and electrolyte interfaces to gain a fundamental understanding of the mechanisms governing their formation and growth. This information will shed new light on a central challenge in developing high-energy rechargeable metal batteries.