Review of ultrasonic methods for monitoring, damage detection, and processing of lithium-ion batteries throughout their life-cycle

TL;DR

This review addresses the challenge of monitoring lithium-ion batteries across their life-cycle by focusing on ultrasonic testing (UT) as a non-invasive probe of mechanical and poroelastic changes linked to electrochemical state. It surveys bulk- and guided-wave UT techniques, Biot poroelastic modeling, and data-driven methods for SOC/SOH estimation, damage detection, and lifecycle inspection. Key contributions include a structured capability gap analysis, a synthesis of UT applications across manufacturing, operation, second-life screening, and recycling, and a roadmap for integrating UT with multi-physics battery models. The work highlights fundamental challenges in linking ultrasonic signals to specific electrochemical processes and translating UT methods to field-deployable solutions, while identifying opportunities in next-generation chemistries and standardized material-property data resources.

Abstract

Lithium-ion batteries (LIBs) are the leading technology used in consumer electronics, electric vehicles, and grid-level electrochemical energy storage applications. The ever-increasing use of LIBs has highlighted a gap in understanding of their behavior throughout their life-cycle. Current monitoring systems rely on electrical and sometimes temperature measurements to assess the internal state which limits information about complex electrochemical processes. In response, ultrasonic testing (UT) has shown promise for non-invasive assessment due to its ease of use and sensitivity to mechanical changes which are correlated with electrochemical changes within the battery. We summarize the research in UT methods applied to LIBs throughout their life-cycle and the relevant techniques at each stage. We also discuss physics-based and data-driven modeling approaches used to interpret ultrasonic signals in the context of LIBs, with an emphasis on the existing challenge of establishing rigorous links between electrochemical behavior and elastic and poroelastic wave physics to gain insight regarding physical changes in the LIB that can be directly measured using UT. Finally, we discuss the challenges of implementing UT across the LIB life-cycle and identify opportunities for further research. This review aims to provide helpful guidance to researchers and practitioners of UT in the growing field of UT for electrochemical battery systems.

Figures (13)

• Figure 1: Some of the main drivers for the increased adoption of LIBs in EV applications: A) forecasted global EV stock (BEV: Battery electric vehicle and PHEV: Plug-in hybrid electric vehicle), B) energy density of LIB packs in EVs, and C) price reduction of LIBs at pack and cell level. Data used to generate figures sourced from Refs. globalEV2025bnefLithiumIonBatteryenergyFOTW1234
• Figure 2: (A) Schematic of ultrasonic wave propagation through a LIB pouch cell, highlighting the layered structure composed of repeating unit cells, which include current collectors (Cu and Al), anode, separator, and cathode. For the porous materials, each layer consists of a solid skeleton and fluid-filled pores (electrolyte). Longitudinal (L) and shear (S) waves propagate through the solids, while only longitudinal waves propagate through the fluid phase. Scale bars are not exact. They are provided as a generic reference scale for microscale (0.5--100 $\mu$m) and macroscale ($>0.1$ mm) features. (B) Scheme of guided wave generation and detection using ultrasonic probes: (B-1) Experimental setup showing guided wave propagation along the z-direction. (B-2) Illustration of symmetric (S) and antisymmetric (A) Lamb wave modes in the LIB pouch. (B-3) Various modes of Lamb waves ($S_{0}$, $S_{1}$, $A_{0}$, $A_{1}$) and their relative particle displacement profiles across the thickness of the pouch.
• Figure 3: Changes in volume and Young's modulus of common commercial LIB cathode and anode materials. During discharge, cathode materials generally exhibit an increase in volume and Young’s modulus, while the graphite anode typically shows a decrease in volume and modulus. Some exceptions to this behavior are observed for LCO and LMO. This figure is based on raw data for the graphite anode Schweidler2018VolumeChangesqi2010threefold Li$_x$C$_6$, and various cathodes koerver2018chemoStallard2022MechanicalCathode: Li$_x$CoO$_2$ (LCO), Li$_x$Ni$\mathrm{_y}$Mn$\mathrm{_z}$Co$\mathrm{_{(1-y-z)}}$O$_2$ (NMC), Li$_x$Ni$\mathrm{_y}$Co$\mathrm{_z}$Al$\mathrm{_{(1-y-z)}}$O$_2$ (NCA), Li$_x$Mn$_2$O$_4$ (LMO). The decrease in volume of cathode materials is generally much smaller than the volume increase of graphite under normal operating conditions.
• Figure 4: Principle fabrication steps in the creation of LIB and comparison of LIB form factors, including cylindrical, prismatic, and pouch cells. A) Assembly process from electrode rolls through various packaging configurations. B) Winding for cylindrical cells, and stacking or Z-folding for prismatic and pouch cells. C) Differences in internal structure and mechanical response under operational pressure are highlighted. These structural differences influence swelling behavior and ultrasonic signal propagation within the cells.
• Figure 5: Number of publications by year on the subject of UT of batteries since 2013, using the relevant papers from the following search criteria in Scopus: TITLE-ABS-KEY (("Li-ion*" OR "Lithium-ion*") AND (ultraso* OR acoustic*) AND (diagnos* OR estimation OR "state of health" OR "state of charge" OR health OR characterization OR monitoring) AND NOT (welding) AND NOT ("acoustic emission")).