Thermal validation with dummy battery cell

The increasing demand for electromobility, portable electronic devices and renewable energy solutions is driving the need for high-performance and long-lasting battery systems. In order for batteries to function reliably over their intended service life, they have to be operated within a specific, narrow temperature window: Thermal validation of the interaction of individual battery cells ensures the safe and efficient operation of the entire battery system.

State of the art

In practice, the thermal validation of battery cells is a difficult balancing act between risky and time-consuming physical tests with real battery cells and simulations based on assumptions. Manufacturing companies rely on physical tests based on applicable standards.

Technology

Researchers at the IPEK – Institute for Product Engineering at KIT and the InnovationCampus Future Mobility (ICM) found the solution in innovative mixed physical-virtual battery cell models (BEM): A "dummy cell" imitates the thermal behavior of a real reference cell, but consists exclusively of chemically inert replacement materials without electrical potential. First, the electrical, thermal and geometric data of a real battery cell or the desired properties of a hypothetical cell are gathered. Based on this data, the design is carried out in a simulation, which depicts the ideal thermal behavior of the cell both internally and externally. This is followed by the transfer to a dummy: a dummy cell is constructed from a suitable replacement material. The cell structure is gradually brought closer to the thermal behavior of the real cell or the "desired cell" using further simulations.

Advantages

The dummy cell enables cost-efficient yet precise analysis of the thermal properties of battery systems. Complex test environments with expensive safety technology and health risks are no longer necessary, at least at the beginning of a development process. In addition, the replacement model opens up completely new validation objectives, such as the investigation of localized temperatures and losses caused by thermal energy.

Options for companies

KIT offers contract work for both SMEs and OEMs and is looking for partners for application-specific development projects and joint research work.