Watch on-demand: Visualizing Li-Metal Anode Battery Degradation
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 inconclusive electrochemical data, which has required the need for nanoscale interfacial characterization of the solid-liquid electrode interfaces.
Our team has used the cryogenic transfer workflow developed by Leica in collaboration with Thermo Scientific cryo-SEM/FIB tools 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. We found that Li-metal plating within the Celgard 2325 and Celgard 2400 separators was common across electrolyte chemistries at high rates >1.5 mA/cm2 after 100 Li plating and stripping cycles for Li-metal half cells.
Watch this webinar to learn more about:
- Advantages of cryo-EM for imaging solid-liquid interfaces
- Advantage of imaging battery electrodes with a cryo stage on a laser plasma focused ion beam
- Opportunities for nano-to-millimeter scale characterization of energy materials and systems
Dr. Katherine Jungjohann, NREL
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.
Brandon Van Leer
Brandon Van Leer joined Thermo Fisher Scientific in 2004 and has held various positions, including Senior Applications Engineer, Applications Manager, and Product Marketing Manager. Currently, he is a Senior Applications & Business Development Manager for DualBeam and SEM instrumentation. Brandon’s professional background has focused largely on materials characterization and development of electronic materials and polymers. He has over 25 years of experience in various analytical techniques and over 19 years exploring SEM and FIB. Brandon’s current research interests are applications development for plasma FIB and multi-ion source plasma FIB. Brandon received his BS in Physics (1998) and his MS in Electrical Engineering (2002) from Oregon State University. He is a member of MSA, MRS, and IEEE.