Discovery Files

Retired electric vehicle batteries could be used to store renewable energy

Engineers research recycling and reusing lithium-ion batteries to optimize design

Researchers at Cornell University, partially funded by the U.S. National Science Foundation, recently published a study that outlines ways to sustainably repurpose used lithium-ion electric vehicle batteries to reduce their carbon footprint. The researchers investigated how battery chemistry, reuse and recycling influence the energy output and environmental impact of lithium-ion EV batteries.

The analysis, published in Science Advances, found that the carbon footprint of a lithium-ion EV battery can be reduced by up to 17% if it is reused before being recycled. Batteries with reduced energy storage capacity can be repurposed to store wind and solar energy. The research is key to manufacturing lithium-ion batteries for electric vehicles that are designed for sustainability instead of performance.

"What to do with all these retired electric vehicle batteries is going to be a huge issue," said Fengqi You, one of the authors of the study. The research team considered environmental and economic tradeoffs in how batteries are built, used and recycled.

"Lithium-ion batteries are designed today for performance and not for recycling or second life," said You. Lithium-ion batteries usually last 12 years or less before losing the capacity to power a vehicle. "There's very little discussion right now about the environmental dimensions of improving battery design for recycling or reuse."

The demand for recycling facilities that can break down lithium-ion EV batteries and extract the raw materials inside currently outpaces supply. Due to the volume of used batteries that will need to be recycled in the coming years, that demand will only grow.