Mechanical material modelling and characterisation of Li-ion battery

Abstract

The increasing demand for sustainable energy solutions has propelled the development of electric vehicles (EVs) and the need for high-performance, reliable batteries. This study focuses on the material modelling of lithium-ion battery cells to enhance their safety and performance under mechanical loads. Initially, a linear elastic model was employed as a preliminary approach to develop the modelling strategy. Subsequently, hyperelastic modelling was explored but revealed a stiffer response than observed in real-world conditions, making it unreliable for capturing the complex behaviour of the battery’s electrode materials. Consequently, a crushable foam material model was implemented, providing a more accurate representation of the electrodes’ response to mechanical loads. Through a multi-scale homogenization process, this study effectively links the mechanical response at the microstructural level to the overall behaviour of the battery cell, providing insights into stress and strain distributions within individual battery components. This approach paves the way for improved modelling strategies in the future that can predict failure scenarios, such as short circuits, thereby contributing to the design of safer and more reliable EV batteries. Limitations of the study include its focus on quasi-static loading conditions and the exclusion of electrochemical and thermal effects, suggesting areas for future research.