Cracking predictions of lithium-ion battery electrodes by X-ray computed tomography and modelling

TL;DR

This paper combines advanced imaging, electro-chemo-mechanical modeling, and fracture analysis to predict electrode fracture in lithium-ion batteries, considering realistic microstructures and various operational conditions.

Contribution

It introduces a comprehensive framework integrating X-ray CT imaging and phase field fracture modeling for realistic electrode microstructure analysis.

Findings

Heterogeneous fracture response depends on particle size and position.

Cracking increases with larger voltage windows and electrode thickness.

Damage sensitivity varies with discharge rate.

Abstract

Fracture of lithium-ion battery electrodes is found to contribute to capacity fade and reduce the lifespan of a battery. Traditional fracture models for batteries are restricted to consideration of a single, idealised particle; here, advanced X-ray computed tomography (CT) imaging, an electro-chemo-mechanical model and a phase field fracture framework are combined to predict the void-driven fracture in the electrode particles of a realistic battery electrode microstructure. The electrode is shown to exhibit a highly heterogeneous electrochemical and fracture response that depends on the particle size and distance from the separator/current collector. The model enables prediction of increased cracking due to enlarged cycling voltage windows, cracking susceptibility as a function of electrode thickness, and damage sensitivity to discharge rate. This framework provides a platform that facilitates a deeper understanding of electrode fracture and enables the design of next-generation electrodes with higher capacities and improved degradation characteristics.