A numerical approach to damage modelling for mechanical assessment of structural batteries

Integrating lithium-ion polymer (LiPo) batteries into composite structures offers the potential to create multifunctional structural batteries that enhance both energy efficiency and structural reinforcement for lightweight design. While current research on structural batteries predominantly relies on experimental methods, there is a need for more systematic numerical studies to assess their structural integrity. This paper presents a holistic finite element (FE) computational model to evaluate the structural batteries’ mechanical performance and damage mechanisms under complex load cases. Various damage criteria and interactive models were employed to examine the behaviour of composite laminates and sandwich composites incorporating LiPo cells. Comparative analysis with experimental data from literature confirmed the FE model's applicability and generality, though it showed slight variations in predictive modulus and post-yielding behaviour under bending. The numerical results indicate that the structural performance depends on specific design configurations and loading types. Sandwich composites exhibited minimal impacts resulting from battery integration, while the composite laminates had a notable decrease in structural strength. In addition, the presence of batteries strongly influenced the loading response and damage modes of the host structures. This numerical work provides valuable insights into the future design and health monitoring of structural energy storage systems.