High-Efficiency Silver Recovery from End-of-Life Photovoltaic Modules via Hydrodynamically Optimized Electrowinning

The proliferation of photovoltaic (PV) installations necessitates sustainable methods for managing end-of-life modules. This study addresses the environmental drawbacks of traditional hydrometallurgical recycling, such as the use of hazardous chemicals and high CO₂ emissions, by developing a novel electrowinning process for silver (Ag) recovery. We introduce an optimized system that synergistically combines a hemispherical stainless-steel cathode, which also serves as the reaction vessel, with magnetically induced forced convection to overcome mass transport limitations. This streamlined technique directly extracts Ag from a nitric acid-based leachate, achieving recovery rates exceeding 99% and a purity of approximately 99.4%. Computational fluid dynamics (CFD) simulations were employed to validate the mechanism, demonstrating that magnetic stirring enhances ion flux to the cathode surface, thereby increasing deposition efficiency. A systematic investigation of process parameters revealed that cathode geometry and stirring speed are critical factors influencing the recovery rate. Compared to conventional chemical deposition methods, the developed process reduces CO₂ emissions by approximately 15%, cuts operational costs by over 65%, and reduces the total processing time by nearly 60%. These findings present a practical, efficient, and more environmentally benign pathway for high-purity metal recovery, contributing significantly to the circular economy for PV materials.