Using Nano-Scale In-situ Electrochemical TEM to Understand Failure Modes in Solid-State Energy Storage Devices
- Abstract number
- 1025
- Event
- European Microscopy Congress 2020
- DOI
- 10.22443/rms.emc2020.1025
- Corresponding Email
- [email protected]
- Session
- PST.6 - In-situ and in-operando microscopy
- Authors
- Dr. Nikhilendra Singh (3), Mr. James Horwath (4), Dr. Timothy Arthur (2), Dr. Daan Hein Alsem (1), Dr. Eric Stach (4)
- Affiliations
-
1. Hummingbird Scientific
2. Toyota Research Institute of North America
3. Toyota Research Institute of North America, Ann Arbor, MI, USA
4. University of Pennsylvania
- Keywords
in-situ TEM
Battery materials
Li-ion batteries
- Abstract text
This work will focus on studying failure modes in solid-state electrolyte energy storage devices using in-situ electrical biasing transmission electron microscopy.
The approach to developing next generation batteries can be split in two directions: engineering optimizations in current lithium-ion battery technology and fundamental studies on new emerging energy storage systems like all-solid state, multivalent or Li-air batteries. Solid state batteries can provide competitive energy densities and may also provide potential safety advantages over traditional Li-ion batteries. Because solid electrolytes have a higher shear modulus, they should suppress Li dendrite growth, which is a common cause of shorting in Li-ion cells. However, in practice, solid electrolytes display decomposition upon contact with Li and the growth of Li dendrites through the solid electrolyte still causing potential shorts. Ideally one would design solid-state batteries with an ideal Solid Electrolyte Interface (SEI) to suppress or eliminate such failure modes.
Previous research has shown that using additives in bulk solid electrolyte (SE) materials like Li3PS4 (LPS) results in a robust SEI at the Li metal/SE interface [1]. In this work we study failure modes in LPS electrolyte materials with and without the addition of a halide. With a site-specific in-situ transmission electron microscope (TEM) biasing sample holder (manufactured by Hummingbird Scientific), it is possible to make very localized electrical contacts to a sample inside the TEM using a movable probe and study the Li-metal and solid-electrolyte surfaces in-situ to gain insight into what causes the failure modes.
Using the in-situ biasing sample holder and Energy Dispersive X-ray Spectroscopy (EDS) in the TEM, we confirmed that simply bringing the surface of the lithium metal in contact with LPS:0.5Lil caused iodine to diffuse through the lithium metal (i.e. through the Li/LPS:0.5Lil interface). Furthermore, we used the n-situ TEM biasing holder to perform in-situ electrochemical cycling. Micron-sized particles were contacted with a mobile probe and cyclic voltammograms were obtained. Currents in the order of picoamps were measured and, simultaneously, electrochemically induced structural changes, within particles and at interfaces, were imaged in the TEM. Comparing LPS and LPS:0.5Lil show significant differences in how Li metal plates and strips from both electrolytes and leads to differences in failure modes.
With the in-situ TEM biasing sample holder tool we were able to directly image the structural changes as they relate to failure in LPS SE Materials during charging and discharging of that solid-state battery material.
- References
[1] Han et.al., Adv. Energy Mater., 8 (18), 1703644 (2018)