​Battery-related accidents are reported in the news on a regular basis. However, they could soon become less frequent! Analyzing the propagation of thermal runaway in lithium-ion batteries is vital to the widespread adoption of these batteries in both stationary applications and transportation.

Liten, a CEA Tech institute, had previously come up with a multi-physics model for runaway in cylindrical battery cells. The institute has now developed the first-ever module-level model for the propagation of thermal runaway from one cell to another.

While extremely accurate, 3D models require substantial computing resources and cannot generate results quickly enough to meet the needs of battery-pack design processes. The impact of thermal runaway propagation diminishes the further away you get from the origin of the thermal defect—a fact that the researchers used to their advantage. They opted to improve the numerical resolution of the problem by combining several models that describe the phenomena with varying levels of detail depending on where they are positioned in the battery pack.

The tool, which leverages several models at different scales, will be expanded to factor in other physical phenomena (such as the combustion or ejection of material) and to offer more predictive capabilities. With a co-developed simplified interface, the tool is intuitive enough to be used by people with no knowledge of numerical methods. Ultimately, the tool will reduce the number of experiments required to design and validate new battery pack architectures. An initial version is now available for testing by design engineers.