New Study Explores Reusing Solar Panel Silicon for High-Performance Batteries

Researchers at UVA are finding innovative ways to give solar panels a second life – by turning them into powerful components for batteries.

As the world increasingly turns to electricity-powered devices, the demand for better energy sources is growing. While fossil fuels still dominate power generation, renewable energy, particularly solar power, has gained momentum due to its environmental benefits and cost-effectiveness.

However, like all technologies, solar panels have a limited lifespan. Considering their large volume and valuable materials, there are concerns about what happens to these panels after use. A key component of solar panels is silicon, which presents an exciting opportunity for recycling and reuse in other applications, particularly lithium-ion batteries.

Silicon has long been used in batteries due to its excellent energy storage capacity. In a recently published study, UVA Environmental Institute faculty affiliates Gary Koenig and Mool Gupta, alongside co-authors, explore how silicon from decommissioned solar panels can be repurposed as an electrode material for batteries. This study offers an eco-friendly and sustainable solution for energy storage.

Gary Koenig, associate professor in chemical engineering at the University of Virginia, works with a team to find end-of-life uses for solar panels. (Photo contributed.)

While traditional methods often pulverize silicon into nano-powders to improve battery performance, Koenig and Gupta used entire silicon wafers from solar panels, making the recycling process even more efficient.

The team of researchers took both untreated and laser-treated silicon wafers and tested their ability to function as battery anodes when paired with all-active material (AAM) lithium cobalt oxide (LiCoO2) cathodes. The laser treatment process modified the surface of the silicon wafers, enhancing their mechanical stability and overall performance. Notably, the silicon wafers demonstrated impressive capacity retention and rate capability, especially when subjected to high current densities, making them a strong candidate for use in real-world batteries.

“This research is significant for the future of both solar and battery technologies,” said Gary Koenig, associate professor in chemical engineering at the University of Virginia. “By using silicon wafers from retired solar panels, we can potentially reduce waste and recycle valuable materials, all while improving battery performance.”

The use of silicon wafers in batteries, especially when combined with AAM cathodes, could help lead to higher capacity, longer lasting, and more sustainable batteries. Such a breakthrough in recycling and reuse paves the way for future advancements in energy storage, with positive impacts on both the environment and technology.

“As solar energy continues to grow globally, this research represents an exciting step toward a circular economy where materials are reused and waste is minimized,” added Koenig. “This is going to help create a more sustainable energy future.”