With a value of 400.3 Mt, the global plastics production increased in 2022 with a plus of 2.5 wt% compared to the previous years. Unfortunately, plastic waste is often disposed of inappropriately, causing environmental problems and an avoidable waste of resources. In 2019, the European Circular Economy Action Plan was issued to encourage plastic recycling. Nevertheless, at the end of 2022, post-consumer mechanically recycled plastics in Europe accounted only for 13.2 wt% of the European plastic production (58.8 Mt). Mechanical recycling fails to recycle mixed, partially degraded, or contaminated plastic waste. Then, there is an acute demand for new, efficient, and cost-effective recycling technologies to fill the gap left by mechanical recycling. Chemical recycling is considered a complementary alternative because it can process waste streams composed of heterogenous and difficult plastics. Currently in Europe, around 58.8 kt (0.1 wt%) of plastic production was obtained by chemically recycled plastics, but the road is marked. The Plastic Europe association announces that its members are going to produce 2.8 Mt of chemically recycled plastics by 2030. Mixed plastic waste is the main target, and pyrolysis and gasification, identified as the suitable technologies for its treatment, represent 80 wt% of the planned capacities.

This study evaluated the feasibility of mechanical recycling of plastic waste recovered from the disassembly of end-of-life lithium iron phosphate battery cases. In particular, the work focused on the case fraction, corresponding to the outer battery envelope, which represents the largest share of the plastic waste by weight. A preliminary characterization was carried out to determine the physico-chemical properties of the material and assess its suitability for mechanical recycling. The polymer matrix was found to consist of polypropylene, with glass fibers and calcium carbonate as inorganic fillers, each present at 18 wt%. X-ray fluorescence and elemental analysis confirmed the absence of elements of concern and subsequently, recycled material processability was investigated, with particular attention to injection molding, the same technology used to manufacture the original battery cases. Rheological analyses confirmed that the material exhibits Newtonian rheological behavior, suitable for injection molding, as also supported by a melt flow index value equal to 7.5 g/10 min (230 °C, 2.16 kg). The material was then reprocessed, and the resulting specimens were subjected to mechanical tests, with impact energy equal to 30.5 kJ/m² and flexural strength amounting to 36.8 MPa. Overall, the recycled material exhibited adequate processability and mechanical performance after one reprocessing step, suggesting its potential for high-value mechanical recycling.