Researchers from Deakin University’s Institute for Frontier Materials have found a way to extract silicon from discarded solar panels and repurpose it into nano-silicon for batteries, potentially eliminating the biggest barrier to photovoltaic cell recycling.
Material scientists Mokhlesur Rahman and Ying Chen, who lead the investigation, said silicon recovery is to key to repurposing discarded solar cells and will prevent the high-value waste from going to landfill.
“Although silicon semiconductors make up a relatively small part of solar panel cells, the material’s value is extremely high. Scientists have been looking for ways to repurpose the silicon for some time, and we believe this to be the missing piece of the puzzle,” Dr Rahman said.
According to the researchers, the average service life of a solar panel is between 15 to 25 years, with modelling suggesting that without silicon recycling there will be 1.5 million tonnes of solar panel waste in landfill by 2050.
“Silicon cells are the most important component of a solar panel, transferring the sun’s energy into electrons. They’re also a high-value material being a chemical element and far too precious to end up as waste, which is why this finding is significant,” Prof Chen said.
“We can’t claim solar panels to be recyclable, in a circular economy sense, until scientists find a way to harvest and repurpose their most valuable components.”
According to Dr Rahman, repurposed silicon can be used to make high-energy anodes, the transporters that move electrons around inside a battery.
“Surprisingly, the recovered silicon seems to work the same way as commercial silicon does,” Dr Rahman said.
“Our preliminary investigation validates the concept of disassembling silicon-based photovoltaic panels, and repurposing the existing silicon into nano-silicon for the battery industry, creating huge potential as an alternative source for the sector.”