The growing applications of lithium-ion batteries underscore the need to divert used batteries from landfills by An energy-efficient process regenerates used cathode particles from spent lithium-ion batteries. Source: David Baillot/UC San Diego Jacobs School of Engineeringrecycling their components. An energy-efficient, non-destructive approach to regenerate Li-ion battery cathode materials was developed at the University of California San Diego and the University of California Los Angeles.

The process involves hydrothermal treatment of cycled electrode particles followed by short annealing, and can be applied to batteries with different capacity degradation conditions. The regenerated lithium cobalt oxide particles retain their original morphology and provide high specific capacity and cycling stability.

Lithium is pre-dosed into the Li-deficient cathode particles, which are then pressurized in a hot, alkaline solution containing a Li salt solution that can be recycled and reused to process more batches. A short annealing process is administered in which particles are heated to 800 degrees Celsius and then cooled very slowly.

New cathodes assembled by researchers from regenerated material and tested in batteries demonstrated the same energy storage capacity, charging time and lifetime as the originals.

The recycling process consumes 5.9 megajoules of energy, equivalent to the energy in about three-quarters of a cup of gasoline, to restore one kilogram of cathode material. Other Li-ion battery cathode recycling processes under development require at least twice that energy.

The researchers hope to advance this process so that it can be used to recycle any type of Li-ion battery cathode material, in addition to lithium cobalt oxide and lithium nickel-manganese-cobalt.