Abstract
An important source of renewable energy is solar energy, and the estimated future growth in this sector will require large amounts of materials and effective recycling processes of the photovoltaic (PV) panels. Given optimized pre-processing, electrowinning can be used to recover metallic Ag from end-of-life c-Si PVs. In this work, the deep eutectic solvent (DES) ethaline was used as electrolyte to effectively produce metallic Ag from a solution prepared by leaching of Ag crystals using FeCl3 · 6H2O as oxidant. The 10 L electrowinning cell was successfully operated at 50 °C for up to 46 h, varying electrolyte flows, current densities, cathode geometry, and diaphragm material to effectively separate the anode reaction. High quality metallic Ag was successfully produced at the cathode from an electrolyte containing 0.1 M Ag ions at a cathodic current density of 7 A/m2. Simultaneously Fe(III) was recovered at the anode to be reused in further leaching steps.