Full Component Cycling of Spent CIGS Solar Cells by Transient Pressure Differential

Abstract

Spent copper indium gallium selenium (CIGS) thin-film solar cells contain valuable metals and toxic elements, making their recycling crucial for a circular economy. The efficient separation of the layers within solar cells is crucial for successful recycling. However, current methods for interlayer dissociation, which rely on pyrolysis and organic reagent dissolution, are slow, produce toxic byproducts, and hinder complete component recovery. This study introduces an innovative instantaneous pressure-difference strategy for separating photovoltaic modules. During the rapid pressure release process, water vapor generates a significant pressure differential, causing the separation of module interlayers owing to the abrupt expansion of water vapor. The proposed method enables the complete separation of all components in waste CIGS cells within 150 s. The method effectively enriches valuable metals and facilitates their leaching recovery., while the separated ethylene-vinyl acetate and polyethylene terephthalate exhibit properties comparable to those of commercial materials. Life cycle assessment indicates that the proposed recycling strategy has a lower environmental footprint and cost compared with conventional methods. Additionally, this approach can be applied to the delamination and recycling of other retired photovoltaic modules. Overall, the strategy provides a viable solution for managing end-of-life solar panels, contributing to the development of a circular economy.