Al3+ driven-hydrolysis of amide group presented in the interface between EVA and glass for the decapsulation of waste photovoltaic laminates

Abstract

With the development of the new energy industry, a large number of photovoltaic modules are produced, used, promoted, and will reach the end of their life cycle shortly. The recycling of photovoltaic modules is an important work in the closed-loop development of the new energy industry, and the first step of recycling is decapsulation. Hydrometallurgical decapsulation has been considered an important recovery method due to energy saving and the ability to recover all components of photovoltaic laminates. However, the problems of low decapsulation efficiency and pollutant discharge need to be solved. This article reports a new green linalool solvent employed for decapsulation. The experimental results show that the delamination rate of the glass of the laminates with particle sizes of 0.5, 1, 2, and 3 cm can all reach 100% in 4 hours. Furthermore, we propose a strategy to improve the efficiency of decapsulation by enhancing the bond-breaking tendency of the crosslinking bridge formed by the coupling agent in the EVA-glass interface. It indicates that the Lewis acid properties of Al³⁺ and its coordination effect with nitrogen atoms promote the hydrolysis of CN bonds in the amid group. The increase of decapsulation efficiency by adding Al³⁺ increases with the decrease of laminate particle size. When the particle size is 0.5 cm and 1 cm, the efficiency is increased nearly two times. This study provides a new idea for improving the green attributes and efficiency of hydrometallurgical decapsulation of photovoltaic laminates.