Novel test methods for battery safety
In this project, a number of novel measurement methods are being investigated independently and then combined to increase battery safety as a whole. Both basic experiments for a deeper understanding and practically applicable solutions are being developed to detect an impending thermal runaway (TR) at an early stage. Temporal information about temperature and gas formation is essential.
With the help of fibre optic sensors, area-wide measurements of cell temperatures at module and pack level can be realised. Due to the advantage of a local resolution along the fibre, the mass of temperature sensors and cabling used in industry can be replaced and leads to significant minimisation integration effort. At the cell level, the ultra-thin glass fibres are placed inside the cell to investigate the extent to which the internal cell temperature can be determined at different points in the cell. Thus, inner hotspots caused by local short circuits allow detection at an early stage with good lateral resolution.
Another project content is the development of new monitoring methods using ultrasound sensors external to the cell. These allow preventive TR detection through the initial gas formation. Besides, highly precise measurements of slightly changed material parameters indicate early battery ageing. In this way, a safety-critical condition can be bypassed and this accelerated ageing can be prevented. This method is being investigated and further developed in NUBase on both, cylindrical as well as pouch cells.
01st November 2020 – 31st Oktober 2023