Using solar energy may be better than the environment burned through fossil fuels, but the process is not completely perfect. Making silicon-based solar panels is energy-intensive and once the panel is used, we still don’t know what to do with silicon.
There is a way to make solar panels using crystal structures called perovskites, also known as photovoltaics (PVS). However, perovskite crystals contain toxic elements such as lead, which needs to be carefully processed once these solar panels reach the end of their lifespan. So far, researchers have had to use toxic organic solvents, such as dimethylformamide, to recycle such solar panels.
A delicious sandwich
Now, in a Publish a paper exist naturescientists have described another possible greener way of solving problems. They used aqueous recovery solutions to report a method for degrading and recycling used perovskites. They are also able to recover high-quality perovskite crystals that can be used again to make new solar cells.
“It’s a complex chemical reaction [the use of] Organic solvents,” said Xun Xiao, a postdoctoral researcher at the Swedish Linköping University.
Perovskite solar cells are composed of multiple layers. The perovskite layer is sandwiched between the materials that can perform and transport charges, in this case, metal electrodes and glass plates.
“People are [perovskite PVs] For ten years or more, because they are able to achieve very high power conversion efficiency,” explained Rhys Charles, a researcher at the Department of Chemical Engineering at Swansea University in the UK. “So you can offer a very cheap solar technology, but there are some things that already hold the rewards in the wild. ”
Stability is one of them: perovskite solar cells have shorter lifespans.
Improve solar energy
“Early attempts to recycle these devices have focused on capturing lead. Now, people have a more comprehensive view of it overall.” “Recycling is also important from a circular economy perspective, because they want to capture the main impact materials,” Charles continued. [that] They use it again. “
For circular economy, the goal is to keep the product (in this case a component of a perovskite solar cell) as long as possible to minimize waste. In this way, if cells are made again by regenerating components, they will have lower environmental impacts, which means lower emissions and lower costs associated with solar generation.
So far, the only way to recycle these important materials is to use toxic organic solvents.
Acid and salt
Dissolving and recycling of lead-containing perovskite layers in water is the main challenge to overcome. To do this, scientists added three key salts to aid in the recycling process.
The first salt they added was sodium acetate. The acetic acid ions bind to the lead ions in the perovskite, so that the highly soluble acetate dissolves in water.
They then added sodium iodide and subphosphoric acid to help regenerate pure perovskite crystals in aqueous solution. Sodium iodide contains iodine ions, which helps repair and restore degraded perovskites, so when the solution cools, high-quality, pure perovskite crystals in the solution reappear from the solution.
The acid acts as a long-term stabilizer to ensure that the aqueous solution can be reused and that the quality of the recovered crystals remains high.
“Solve the Problem”
“I’m glad to see this focus on recycling, remanufacturing and green chemistry,” said Matthew Davies, professor of chemical engineering at Swansea University. “It laid the foundation for perovskite PVS to deliver on the promise of low-cost, efficient solar technology in a circular economy, thus avoiding the massive waste challenges faced by early PV technologies.”
The scientists also developed solutions made from ethanol and ethyl acetate to dissolve other components of perovskite solar cells, after which they were able to recycle each component along with perovskite crystals for reuse. They then reassembled the solar cells layer by layer and found that even after five recycles, the efficiency was almost the same. Even after multiple rounds of recycling, they were able to reverify about 99% of the different layers.
“These guys seem to have solved the problem; they seem to be able to use this aqueous system to recycle cells and make them again with high efficiency, making them again,” Charles said. “If you can scale it,” [up] And, if its role and what the paper claims is, it may overcome some of the most important obstacles to commercializing perovskites and address some of the critical environmental issues to the technology. ”
Charles also stressed the need to support scientific and industrial advancements, especially in environmental technology, as well as life cycle assessments. He explained that from the beginning to the end of the product, life cycle evaluation is a way to quantify all the impact of technology throughout the life cycle. “But you can go further,” he said. “You can then look at the stages of use and end-of-life of the technology, too.”
“When I see these things based on lifecycle evaluation, I always like it to make sure there are no unexpected consequences and to make sure the research is really targeting the critical environmental issues of the technology,” Charles added. “I also want to see more, like standard practice.”
Rohini Subrahmanyam is a freelance journalist in Bangalore.
publishing – April 21, 2025 05:30 AM IST
