Developing a digital twin to inform safer design

Battery abuse testing is costly and time consuming and experiments can be difficult to carry out in laboratory settings. In such studies, cells are deliberately driven into thermal runaway (where cell temperature spirals upwards and eventually results in a fire) so that thermal runaway propagation through a group of cells can be studied to inform the development of mitigation strategies. Simulating different scenarios of thermal runaway propagation using a digital twin can significantly accelerate research efforts. Combining and validating the model with experimental data provides a powerful tool to inform module and pack design.

Researchers at the University of Oxford and WMG, University of Warwick have developed a digital twin representation of a cell cluster to investigate the complex multiphysics processes involved in thermal runaway. This approach offers a rapid, cost-effective and safe platform for battery failure testing.

In this research, thermal runaway evolution was simulated by integrating electrochemical and decomposition reaction kinetic sub-models. Propagation of thermal runaway in a seven-cell cluster – induced by axial nail penetration and accompanied by high temperature gas emission from sidewall rupture – was simulated using a computational fluid dynamics turbulent flow sub-model and validated experimentally.

The model was then used to analyse the properties of thermal barrier materials used in battery design and their effectiveness in preventing thermal runaway propagation. The modelling complements experimental work at WMG. The simulation indicated that materials with thermal diffusivities lower than 0.3 mm/s can prevent thermal runaway propagation in a non-enclosed cell cluster. Such use of digital twins is an invaluable tool for designing battery thermal management systems and will enhance safety.

Image: An image of a digital twin representation (left) of the seven-cell experimental cluster (right). The photo shows the cells after thermal runaway, propagating throughout the cluster from an induced side-wall rupture in one cell. The digital twin accurately predicted thermal propagation to adjacent cells caused by the release of hot gases/flames from the side wall rupture in the initiating cell.

Case study published December 2025.