Cornell Researchers Develop Sustainable Solar Cell Recycling Process

In a significant advancement for sustainable solar energy, researchers from Cornell University and Linkoping University in Sweden have unveiled a novel, aqueous-based method for recycling perovskite solar cells.

This breakthrough addresses critical sustainability concerns surrounding the next-generation photovoltaic technology and paves the way for wider adoption. Perovskite solar cells have shown immense promise due to their high efficiency and low-cost manufacturing compared to traditional silicon-based cells. However, challenges related to toxicity, limited recycling options, and resource depletion have hindered their widespread use.This new recycling process directly addresses these challenges.

Published in the journal Nature, the study details a scalable and environmentally friendly approach that utilises a green solvent to selectively dissolve degraded perovskites. This process allows for the recovery of key materials, including high-quality perovskite crystals, which can then be directly reintegrated into the production of new solar cells without significant performance loss.

"This study provides a sustainable path forward for perovskite photovoltaics," said Fengqi You, the Roxanne E. and Michael J. Zak Professor in Energy Systems Engineering at Cornell University and senior author of the study. "By using an aqueous-based process, we can effectively recover key materials, minimise hazardous waste, and promote circularity in the solar industry."

The research team conducted a comprehensive sustainability analysis, demonstrating the remarkable impact of their new method. Compared to simply landfilling spent solar cells, the aqueous recycling process reduces resource depletion by an impressive 96.6% and decreases the human toxicity impact by 68.8 percent. Furthermore, the economic benefits are substantial. The levelized cost of electricity, a crucial metric for economic viability, is reduced by 18.8 percent for utility-scale systems and 20.9 percent for residential systems.

Key contributions to the research came from graduate students Xueyu Tian and Bingzheng Wang from Professor You’s research group, who spearheaded the life cycle assessment and techno-economic analysis.

This breakthrough comes as part of broader efforts to establish sustainable practices within the perovskite solar industry. Professor You, also the director of the Cornell AI for Sustainability Initiative (CAISI), emphasises the importance of integrating sustainability frameworks into the perovskite solar sector. He believes that combining technological innovation with comprehensive sustainability analytics is crucial for bridging the gap between scientific discovery and real-world applications.

The research was supported by the National Science Foundation and Schmidt Sciences, LLC, through Cornell University’s Schmidt AI in Science Postdoctoral Program, which Professor You co-leads. The Zak Family Seed Fund in Energy Systems Engineering, established by Michael Zak '75, also provided indirect support for the project.