Speakers
Invited Speaker
An interfacial understanding is necessary for developing strategies to commercialize high-energy density rechargeable lithium metal anode batteries, as currently, the lithium anode/electrolyte interface is unstable with prolonged cycling. We have used several strategies to improve the cycling performance of lithium metal anodes, including reducing the parasitic reactions between lithium metal and the electrolyte, and improving the electrodeposited lithium metal morphology. These strategies have generated unconclusive electrochemical data, that has required the need for nanoscale interfacial characterization of these solid-liquid interfaces. Our team has used the cryogenic transfer workflow developed by Leica in collaboration with cryo-SEM/FIB tools by Thermo Fisher Scientific to cross-section lithium metal anodes and intact coin cell batteries to observe the interfacial structures, lithium morphology, and failure mechanisms relative to changes in electrode contract pressure and electrolyte chemistry. Cross-sectional SEM images and EDS maps of the lithium metal anodes have provided a better understanding of the electrodeposited lithium morphology, quantity of ‘dead’ lithium metal, and quantity of solid electrolyte interphase material that has formed alongside the lithium metal. In understanding lithium metal battery failure at the system level, we used a cryogenic stage in a laser plasma FIB to cross-section through the coin cell’s cap for imaging/mapping the entire battery stack under cryogenic conditions. The tools, methods, and results of these studies will be detailed in this presentation.
Talk Title: Nanoscale Electrode Interfaces Revealed with Cryo-Electron Microscopy
National Renewable Energy Laboratory
Bio: Dr. Jungjohann joined NREL in 2021, after starting her career within DOE’s Nanoscale Science Research Centers, including the Center for Integrated Nanotechnologies and the Center for Functional Nanomaterials. Her research began with liquid-cell scanning / transmission electron microscopy (S/TEM) of nanoparticle synthesis and catalytic nanoparticles. During her tenure at Sandia National Laboratories, she worked heavily on Li-metal anode characterization using in-situ electrochemical S/TEM and cryogenic electron microscopy methods. In addition, she led two development projects to advance in-situ S/TEM capabilities. Dr. Jungjohann supported research on an array of user projects that required in-situ S/TEM (electrical biasing, electrochemistry, heating, heating in liquids, cryogenic, straining, and environmental TEM). She now supports her group’s role in providing advanced analytical microscopy and imaging characterization to NREL and NREL’s collaborators.