New ultrasound method will contribute to more battery reuse

Batteries have a central role in the green transition and the electrification of society, both in Norway and globally. In the transport sector, both on land and at sea, large quantities of lithium batteries will be replaced in the years to come.

- Reuse and recycling of such batteries are therefore essential to make production more sustainable and reduce the emissions of CO₂ associated with production. Lithium is also a scarce resource that is both very expensive and resource-intensive to extract, says Geir Nævdal, researcher at NORCE and project manager for this new battery project.

The project is a collaboration between researchers in NORCE and the Institute for Energy Technology (IFE) and the companies AS Batteriretur, Corvus Energy AS, Hydro Energy AS, and Repack AS. The project is funded by the Regional Research Fund Vestland.

Complex to recycle

The lithium batteries used in electric cars and in a maritime context are completely different from traditional starter batteries. These are large high-energy propulsion batteries that have many more cells, completely different chemistry, and much more energy packed into them, they can weigh up to several hundred kilos and are complex to recycle. Electric car batteries are considered ready for replacement at 80% of original capacity, but usable battery cells and modules may still have a potential for further use in new applications.

- A challenge when reusing batteries is that there is a lack of good and accurate methods for determining the health status of the batteries, says Nævdal.

Small and thin battery cells have previously been examined with ultrasound, while ultrasound examinations of cells and modules for high-energy propulsion batteries are something new and original.

The transition from hydrocarbon-based to electric-based energy is an important part of the green transition, and batteries play a key role in this shift. Monitoring systems that ensure efficient and targeted use of these will therefore be an important part of the shift. It should also be a goal to have the most sustainable battery management possible, i.e. that the imprints during production and recycling should be as small as possible, and that the life of the battery cells is extended through reuse. To optimize this, robust and effective methods are needed to detect the health status of the batteries.

If this leads to increased reuse of used batteries, it will make battery production more sustainable and reduce the climate footprint. If the measured state of health reveals potential risks with the use of the battery, it will also reduce the risk of unforeseen events such as fire.

Expertise from oil and gas

The researchers have previously used ultrasound in the oil industry and within medical technology. The project group has transferable expertise from reservoir characterization, as well as measurements and simulations related to oil and gas flow.

Knowledge and methodology from the project can also be used in areas other than battery technology, areas that are central to the green transition, for example in the development of fuel cells.