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!

  • dogphlap dogphlap

    This is a welcome development but the 5% figure for recycled batteries would be unlikely to apply to EV batteries, after all the nearest comparison would be automotive lead acid 12V batteries which are claimed to be the most thoroughly recycled item on the planet, in the high ninety percents (97% in the US). Lithium is not a problem but cobalt and nickel have the potential to be. It’s probably time for some thought to be put into possible future legislation to ensure battery packs do get returned to the manufacturer or an approved recycling facility at the end of their life (including any secondary life e.g. household grid backup/load shifting) but the cost of these elements is high enough that the financial incentive could be enough to ensure very high levels of recycling without any additional encouragement. Before we beat ourselves up over this it turns out EVs are yet to become the problem their detractors would like us to believe, the batteries are not the major users of these elements (Cobalt is used in special alloys e.g. high temperature turbine blades and still used as a pigment while every piece of stainless steel cutlery has 8 to 10% nickel by weight) yet we hear very little vitriol directed to these uses and their recycling percentages.