Quantitative characterisation of the layered structure within lithium-ion batteries using ultrasonic resonance

TL;DR

This paper introduces a non-destructive ultrasonic resonance technique to quantitatively analyze the layered internal structure of lithium-ion batteries, providing critical insights into their internal states for improved quality control and health monitoring.

Contribution

A novel physical model and ultrasonic method for detailed, non-destructive internal characterization of LIBs, including layer count, thickness, and charge distribution.

Findings

Successfully identified internal layer structures and thicknesses.

Enabled real-time monitoring of charge states across layers.

Demonstrated potential for quality control and safety assessment.

Abstract

Lithium-ion batteries (LIBs) are becoming an important energy storage solution to achieve carbon neutrality, but it remains challenging to characterise their internal states for the assurance of performance, durability and safety. This work reports a simple but powerful non-destructive characterisation technique, based on the formation of ultrasonic resonance from the repetitive layers within LIBs. A physical model is developed from the ground up, to interpret the results from standard experimental ultrasonic measurement setups. As output, the method delivers a range of critical pieces of information about the inner structure of LIBs, such as the number of layers, the average thicknesses of electrodes, the image of internal layers, and the states of charge variations across individual layers. This enables the quantitative tracking of internal cell properties, potentially providing new means of quality control during production processes, and tracking the states of health and charge during operation.