Operando 2D Acoustic Characterization of Lithium-Ion Battery Spatial Dynamics

Abstract

Spatially sensitive operando characterization techniques provide fundamental insights into dynamic and complex electrode phase behaviors of electrochemical cells during operation. However, real-time characterization of cell-level phase behavior during fast-charging has primarily been limited to synchrotron tools. We demonstrate a significant advance in the use of acoustic characterization for batteries by enabling spatially resolved operando scanning to detect local variations in phase behavior for the entire cell area during charging at all practical rates. Amplitude attenuation during fast-charge is shown to arise from localized lithium metal plating near the welded tab locations. Differential amplitude analysis takes advantage of the electrochemical-mechanical coupling of graphite staging dynamics to visualize the varying extent of graphite lithiation at different locations on the pouch cell. These time-domain modalities are coupled with frequency-domain images from Fourier transforms. Analyzing anode-free lithium metal pouch cells demonstrates that rapid and spatially heterogeneous attenuation in suboptimal electrolytes is because of electrolyte consumption initiating from electrode edges after deposition of an initial porous layer.

Advances and challenges in multiscale characterizations and analyses for battery materials

“…Reproduced with permission from Ref. [140] Copyright 2021 American Chemical Society. (f ) Operando amplitude scanning.…”

Ultrasonic Tomography Study of Metal Defect Detection in Lithium-Ion Battery

“…In comparison, these disadvantages associated with air coupling are nonexistent when sound waves propagate in liquids. For scanning and imaging of small batteries, the liquid coupling method used by Deng et al ( 2020) is superior to the air coupling method used by Li and Zhou (2019) and Chang and Steingart (2021). Therefore, the non-contact-multiple acoustic channel-battery in situ testing (NCMAC-BIST) methodology proposed in previous work (Yi et al, 2021) was applied in this study.…”

“…Deng et al (2020) analyzed electrolytes in terms of their wetting effects and gas generation based on variations in C-scan images. Chang and Steingart (2021) investigated color-palette variations in the C-scan images of batteries at different numbers of cycles and discovered internal Li-plating areas. Li and Zhou (2019) ultrasonically imaged and simulated pores of different sizes and at different depths in batteries.…”

Evaluating Interfacial Stability in Solid-State Pouch Cells via Ultrasonic Imaging

“…The ultrasonic waves at certain positions cannot represent the internal state across entire LIBs due to the lack of spatial resolution. ,, Recently, we pioneered ultrasonic imaging technology to study the wetting behavior of liquid electrolytes in the pouch cells . Then, ultrasonic imaging was used to visualize the defects and local variations in coin and pouch batteries, such as electrolyte leakage and gas accumulation. − Different from the fixed-point testing, a focused ultrasound beam with a diameter less than 1 mm is scanned with a position control accuracy of 0.2 mm, which leads to submillimeter resolution . The excellent resolution in vivid ultrasonic images shows the feasibility of using this method to investigate the interfacial stability of SSBs, where interfacial degradation and contact loss are critical issues.…”