New life for solar silicon
Battery breakthrough creates value from waste
GEELONG material scientists have found a way to recover silicon from waste solar panels and convert to a highly expensive battery grade nano-silicon with potential to be used in electric car batteries.
The breakthrough by Deakin University’s Institute for Frontier Materials researchers Dr Md Mokhlesur Rahman and Professor Ying Chen solves the biggest problem preventing discarded solar panels being recycled.
Proof of the concept is being hailed as the Holy Grail of repurposing, taking a product that would otherwise be waste, recycling it, and in the process making it even more valuable as battery grade nano-silicon, which retails for more than $44,000 a kilogram.
Deakin University and the State Government have contributed $300,000 to the project, which now requires major industry backing to move to largescale production.
According to the researchers, the average service life of a solar panel is between 15 to 25 years with modelling showing that, without a silicon recycling process, by 2050 there will be about 1.5 million tonnes of solar panel waste in landfill.
The bulk of a solar panel is glass, metal and plastic materials with only a small part made from silicon.
Dr Rahman said that lithium-ion batteries with high energy and power density, potentially for use in electric vehicles, can be developed from recovered nano-silicon.
“Our discovery addresses several significant challenges currently facing industries dependent on batteries and energy storage heading into the future,” Dr Rahman said.
“First, being such an exceptionally high-value commodity with widespread applications we do not want any of this precious product wasted.
“Second, with the automotive industry set to be battery driven in the future, the push to find ways to increase battery capacity is growing.
“Part of the silicon repurposing process is to nano-size the battery grade silicon, leaving a nano-silicon which can store about 10 times more energy in the same space.”
Dr Rahman said it was anticipated that valuable IP would be developed as a result of the breakthrough and Deakin would work with industry to find the optimum commercialisation path.
There has been support by Institute for Frontier Material’s Circular Economy strategy lead Catherine McMahon in collaboration with Deakin Research Innovations’ senior commercial manager, Andrew Rau, and industry partner Delaminating Resources Melbourne.