Gabriela

Holistic development of thermoplastic recycling routes for resource-efficient and circular lightweight battery housings

In the TTP-LB joint research project GABRIELA, recycling pathways for high-performance plastics in the automotive industry were developed. The focus was on creating an adapted closed-loop recycling strategy for the “Pentatonic” high-voltage battery housing produced by the automotive supplier Kautex Textron. The three-year research project was successfully completed in November 2025. The final report is available under DOI 10.34657/37349.

To comprehensively investigate the recycling potential of structurally relevant lightweight components, two recycling scenarios were analyzed: mechanical recycling and physical recycling. The starting point was the large-scale production of battery housings for electric vehicles made of plastic reinforced with up to 50% glass fibers. The project examined the entire life cycle of a fiber-reinforced plastic battery housing, from material production and initial processing to ageing during use, reprocessing, and reuse in the same component.

The ILK focused on investigating the influence of the use phase and the reprocessing scenarios within the closed-loop system on the material properties of the composite. For this purpose, the use phase was modelled in the project by means of accelerated ageing on a pilot scale. The material properties were determined at all stages of the simulated life cycles using mechanical and physical testing methods. The work shows that solvent-based recycled plastics, when subsequently processed by compression molding with inline fiber feeding, exhibit barely measurable property degradation and can therefore be used safely even at very high recycled-content levels of up to 100%. Mechanically recycled materials processed by injection molding show slight degradation. However, by blending them with virgin material, the material properties can largely be maintained even at recycled-content levels significantly above 50%, thereby ensuring safe application in this case as well.