Could recycled solar panels hold the key to next-generation lithium batteries?

Chinese scientists have turned discarded solar cells into high performance lithium battery material that could be used for EVs and grid-scale energy storage

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Researchers have created silicon battery anodes and combined them with a new type of electrolyte to make a lithium battery that can hold more energy than batteries with traditional graphite anodes. Photo: AFP

Victoria Bela

Published: 6:00pm, 27 Jul 2024

Scientists in China have found a way to build a longer lasting lithium battery by using discarded solar panels.

The researchers created silicon battery anodes and then combined them with a new type of electrolyte to make a lithium battery that can hold more energy than batteries that have traditional graphite anodes.

“Lithium-ion batteries based on graphite anodes are rapidly approaching their energy density ceilings [300 watt-hours per kg] but cannot meet the ever-increasing demands of electric vehicles,” the researchers wrote in a paper published in peer-reviewed journal Nature Sustainability on July 16.

The “silicon … anode is widely viewed as a game changer for lithium-ion batteries due to its much higher capacity than the prevalent graphite and availability in sufficient quantity and quality,” the team from the Qingdao Institute of Bioenergy and Bioprocess Technology wrote in the paper.

When fashioned into a pouch battery – a type of lithium-ion battery featuring a flexible, lightweight design that is used to power electric and hybrid vehicles – the anode and electrolyte achieved an energy density of 340 watt-hours per kg for 80 charging and discharging cycles, well beyond the limit of graphite anodes.

The low-cost silicon anodes (the negative electrodes) had an average coulombic efficiency – or charge efficiency – of 99.9 per cent, and were able to retain 83.1 per cent of their capacity after 200 charging cycles.