Ultrasonic damage detection in lithium-ion cells with localized thermal abuse histories

Abstract

Electric vehicles require nearly 1000 individual lithium-ion batteries to provide appropriate power and capacity. It has recently been shown that ultrasonic inspection can detect localized heating in a LIB cell with a combination of input frequencies and propagation paths [J. Acoust. Soc. Am. 152, A283 (2022)]. However, monitoring the thermal conditions of every cell in a battery pack is highly challenging to implement. This work explores the use of ultrasonic inspection to diagnose LIB cells with damage histories due to local, thermal abuse. LIBs were interrogated with ultrasonic waves while subjected to electrical and thermal loading, specifically, standard charge-dischargecycling followed by moderate localized thermal abuse and another phase of charge-discharge cycling. Ultrasonic signals from each portion of the test and data for the cycling before and after heating are directly compared for indicators of past abuse. Experimental data are compared to a transfer-matrix model to simulate the time-of-flight (TOF) through an individual cell using temperature-specific material properties for individual components to simulate the effect of heat on TOF. Experimental results indicate that deviations in time-domain features of the received signals can be used to detect previous thermal abuse via ultrasonic testing during charge-discharge cycling after thermal abuse.