Electro-chemo-mechanical modelling of structural battery composite full cells

Abstract

Structural battery composites are multifunctional materials capable of storing electrochemical energy and carry mechanical load at the same time. In this study, we focus on the laminated structural battery design developed by Asp and co-workers, which utilises multifunctional carbon fibres as both active material and mechanical reinforcement in the negative electrode. The positive electrode consists of active lithium iron phosphate particles adhered to an aluminium foil. Building upon previous research, we develop a fully coupled numerical multiphysics model to simulate the charge–discharge processes of the structural battery full cell. The model includes non-linear reaction kinetics, pertinent to the Butler–Volmer relation. Furthermore, we employ a simplified continuum representation of the porous positive electrode, enabling simulations at the battery cell level. Available experimental data for material parameters is utilised when possible, while the remaining parameters are obtained from calibration against experimental charge–discharge voltage profiles at two different rates. Results show that the presented model captures the general trend of the experimental voltage profiles for a range of charge rates. Through this work, we aim to provide insights for future structural battery design efforts.