Aging-induced degradation and contaminant evolution in photovoltaic module laminate components for enhanced mechanical recycling

The projected global increase in photovoltaic (PV) deployment is expected to generate substantial volumes of end-of-life waste by 2050, highlighting the urgent need for advanced circular recycling strategies. High-purity recovery of silicon and glass from decommissioned modules is significantly impeded by the strong interfacial adhesion of cross-linked ethylene-vinyl acetate (EVA) encapsulant. This study systematically correlates aging-induced EVA degradation with the contaminant profiles of individual PV laminate components across sequential stages: lamination, accelerated aging, and thermal delamination. Cleanliness levels of recovered glass, silicon cells, busbars, and backsheets were evaluated using Fourier Transform Infrared Spectroscopy (FTIR), Energy Dispersive X-ray Spectroscopy (EDS), and optical microscopy to determine their suitability for direct mechanical recycling. Analytical results indicate that silicon cells retain the highest levels of persistent organic residues, whereas recovered glass and busbar fractions exhibit only trace contamination under the tested conditions, supporting their readiness for high-quality secondary applications. Accelerated aging was found to promote EVA degradation, thereby reducing organic residues in samples equivalent to 20 years of service. To further enhance clean separation, 20 nm aluminium coatings were deposited by physical vapour deposition (PVD) and magnetron sputtering prior to encapsulation; this method reduced EVA interfacial adhesion and significantly improved delamination efficiency. By directly linking aging-induced degradation to contaminant evolution, these findings provide a scalable and industrially compatible pathway to optimise PV material recovery and support the development of a closed-loop solar economy.