Abstract:
A wet chemical recycling approach was adopted, utilizing a potassium hydroxide (KOH) solution to leach the aluminum back-surface from solar cells. The influence of three key experimental parameters, the mass percentage of KOH solution, molar ratio of KOH to the aluminum back-surface in the cells, and reaction conditions on the leaching rate of the aluminum back-surface were investigated. A series of single-factor gradient experiments and cross-variable experiments were designed, covering KOH solution with a mass percentage ranging from 20% to 70% and solid-to-liquid ratios from 1∶10 to 1∶60, while controlling reaction conditions to determine the optimal parameters for aluminum back-surface leaching. The morphological changes and elemental composition variations of the aluminum back-surface before and after the leaching reaction were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results demonstrated that the optimal leaching effect was achieved under the following conditions: KOH solution with a mass percentage of 20%, solid-to-liquid ratio of 1∶20, and reaction temperature of 70 ℃.