Reusing Silicon From Waste Modules For Batteries

• A research work of the Deakin University claims to have discovered a way to extract silicon from discarded solar cells at the end of their working life
• This silicon can then be repurposed to be used a nano-silicon to make batteries that could be used to make high-energy anodes and transporters
• It claims this battery grade nano-silicon can store up to 10 times more energy in the same space

Researchers at Australia's Deakin University claim to have discovered a way to extract silicon from discarded solar panels which then could be used as nano-silicon for batteries. The team at the Deakin Institute for Frontier Materials argue that this is the 'key' to repurposing discarded solar cells that will prevent high-value waste from going to landfill.

Researchers Dr Md Mokhlesur Rahman and Prof Ying (Ian) Chen at the Deakin Institute for Frontier Materials explain that post the average service life of a solar panel of between 15 years and 25 years, if not recycled they could add up to 1.5 million tons of solar panel waste in landfills by 2050 – that's the equivalent of about 100,000 small cars. If silicon is extracted and recycled from these discarded panels, it could be used to make high-energy anodes that automotive companies and battery manufacturers stockpile as the material for future use with the lithium-ion batteries market quickly growing.

According to the researchers, battery grade nano-silicon is highly expensive and retails for more than $44,000 per kg. So, any such material that can be repurposed should be a money saver option.

"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," said Chen. "It's the holy-grail of repurposing – to take a product that would otherwise be waste, recycle it, and in the process make it even more valuable at the other end."

With the current spurt in solar panel installations across the globe, the industry and markets have been thinking of ways to manage this fleet at the end of its working life. Indian market intelligence firm Bridge to India suggested India to have a policy framework to deal with massive volumes of solar PV waste that it estimated to grow up to 1.8 million tons by 2050 (see 1.8mn Tons Solar Module Waste In India By 2050).