Work

Investigating wetting and formation behavior of consumer format pouch cells utilizing ultrasound

Year: 2025

Type: article

Abstract: Methods to detect electrolyte wetting in lithium-ion batteries (LiBs) are limited, but ultrasound (US) techniques have emerged as a promising solution. In this study, wetting behavior in consumer-format pouch cells (5 × 3 cm) was examined using US transmission, electrochemical impedance spectroscopy (EIS), and dyed electrolyte. The results indicate that wetting is almost immediately completed to a sufficient degree. Residual gas pockets, detectable using ultrasound, seem to take a long time to dissolve in the electrolyte or to migrate out to the sides of the pouch on their own. US measurements imply that these remaining gas pockets are expelled during the formation process due to expansion of the graphite anode during lithiation. The gas pockets initially present are not harmful to cell performance, as shown by aging measurements and the absence of plating after formation. Consequently, the formation process can be initiated almost immediately after filling in this cell format. • Ultrasound reveals near-instant electrolyte wetting in consumer pouch cells. • Sufficient wetting is confirmed by EIS, dyed electrolyte, and performance tests. • Ultrasound offers superior sensitivity to degree of wetting over EIS. • Residual gas pockets dissolve slowly but pose no harm to cell performance. • Gas pockets are expelled during graphite expansion, confirmed by ultrasound.

Source: Journal of Power Sources

DOI: 10.1016/j.jpowsour.2025.236988

Authors: Simon Feiler, Jannis Johann, Lukas Gold, Andreas Gronbach, Guinevere A. Giffin

Institutions: Fraunhofer Institute for Silicate Research, University of Würzburg

Language: English

Topic: Advanced Battery Technologies Research

Subfield: Automotive Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: hybrid

Estimated APC paid: $4,230