Using transient grating spectroscopy to better understand lithium electrodeposition
Using transient grating spectroscopy to better understand lithium electrodeposition lead image
Lithium batteries are utilized in applications ranging from smartphones to solar energy storage. Nonetheless, safety concerns abound because batteries short-circuit due to the internal deposition of lithium metal. The reactivity of lithium metal consequently necessitates developing in situ and operando techniques to better understand lithium metal within a battery. Unfortunately, characterizing the initial stages of lithium metal deposition is challenging as the lithium metal is buried beneath other battery components.
Yang et al. use transient grating spectroscopy (TGS) probe lithium electrodeposition at the current collector-electrolyte interface of a lithium-ion battery in situ and with a high spatial. This method employs multiple lasers to generate an acoustic wave in the current collector that encodes information about the mechanical properties of the substrate underneath. The probing depth is further tunable by changing the laser incidence angle.
“We believe TGS can potentially provide valuable in situ/operando insights into the factors that impact lithium deposition,” said co-author Bolin Liao. “Such results would aid in developing next-generation, high-energy-density batteries, including lithium-metal and lithium-sulfur batteries.”
By employing TGS to probe a cell, the researchers significantly increased the spatial resolution of their measurements down tens of micrometers compared to previous works utilizing acoustic methods, which have made bulk measurements of full cell volumes. The increase in spatial resolution enabled them to probe lithium nucleation and growth.
“We found that changes in the acoustic wave taken at different points during the lithium electrodeposition process strongly correlated with the stages of lithium growth,” said co-author Szeto.
Going forward, the researchers plan to apply TGS to study microstructural changes in other electrode materials and commercial lithium-ion batteries in response to dynamic thermal environments.
Source: “In situ monitoring of lithium electrodeposition using transient grating spectroscopy,” by Runqing Yang, Harrison Szeto, Brandon Zou, Emily Spitaleri, Bolin Liao, and Yangying Zhu, Applied Physics Letters (2023). The article can be accessed at https://doi.org/10.1063/5.0166360 .
