Recycling worn cathodes to make new batteries

As lithium-ion batteries proliferate, the question of what to do with them when they wear out is becoming a major environmental concern. Less than five percent of used batteries are recycled today.

Nanoengineers at the University of California San Diego have developed an energy-efficient recycling process that restores used cathodes from spent batteries and makes them work just as good as new.

As the researchers explain in a paper published in Green Chemistry, the new method can be used to recover lithium cobalt oxide, which is widely used in consumer electronics. The method also works on nickel manganese cobalt (NMC), a cathode material which is used in many EVs.

Researchers pressurized recovered cathode particles in a hot alkaline solution containing lithium salt, then put them through an annealing process in which they were heated to 800° C and then cooled very slowly. They made new cathodes from the regenerated particles and found them to have the same energy storage capacity, charging time and lifetime as the originals.

“Think about the millions of tons of lithium-ion battery waste in the future, especially with the rise of electric vehicles, and the depletion of precious resources like lithium and cobalt,” said Professor Zheng Chen. “Mining more of these resources will contaminate our water and soil. If we can sustainably harvest and reuse materials from old batteries, we can potentially prevent such significant environmental damage and waste.”

Recycling cathodes would also save money. “The price of lithium, cobalt and nickel has increased significantly,” said Chen. “Recovering these expensive materials could lower battery costs.”

Chen’s team is refining the process so that it can be used to recycle any type of cathode material, and is also working on a process to recycle used anodes.


Source: UC San Diego via EurekAlert!