Recycling of Li-Ion Batteries (LIBs) is still a topic of scientific interest. Commonly, spent LIBs are pretreated by mechanical and/or thermal processing. Valuable elements are then recycled via pyrometallurgy and/or hydrometallurgy. Among the thermal treatments, pyrolysis is the most commonly used pre-treatment process. This work compares the treatment of typical cathode nickel-cobalt-aluminum (NCA) material by conventional pyrolysis, and by a microwave assisted pyrolysis. In the conventional route, the heating is provided indirectly, while via microwave the heating is absorbed by the microwaves, according to the materials properties. The comparison is done with help of a detailed characterization of solid as well as the gaseous products during and after the thermal treatment. The results indicated at least three common stages in the degradation: Dehydration and evaporation of electrolyte solvents (EC) and two degradation periods of EC driven by combustion and reforming reactions. In addition, microwave assisted pyrolysis promotes catalytic steam and dry reforming reactions, leading to the strong formation of H₂ and CO.

The surge in Waste Electrical and Electronic Equipment (WEEE) generation, reaching 53.6 million metric tons (Mt) in 2019, demands efficient recycling solutions. This study focuses on the Shredder Light Fraction (SLF), a material stream derived from the mechanical pre-processing of WEEE, which is considered "municipal waste". SLF constitutes 4.2% of the output material and is rich in metals like copper, tin, lead, zinc, silver, and gold. Pyrolysis treatment was applied to SLF, enabling recyclability. Both batch and continuous setups were employed for materials flow analysis and technical evaluation of the resource potential. The research evaluates the impact of pyrolysis technology on solid fraction metal content and pyrolysis gas/oil energy potential. Scaling up the process addressed material heterogeneity and increased the reliability of the obtained results. An innovative pyrometallurgical extraction approach was suggested, to recover valuable metals in SLF which otherwise could be lost via energy recovery methods. The resulting solid product after pyrolysis showed enriched concentrations of copper, zinc, lead, and precious metals with concentrations acceptable for industrial use. Additionally, it displayed reduced mass and diminished hazardous constituents. The non-condensable gas, rich in hydrogen, carbon monoxide, and methane, exhibited potential as an alternative energy source or reducing agent in the metallurgical sector. This research advances metal recycling from SLF, offering valuable insights for environmental impact mitigation as waste was transformed into a valuable by-product for potential use in the copper industry.