Lithium-ion batteries power phones, cars, and renewable energy storage. As more people use them, old batteries pile up. Recycling them helps the environment. It also recovers metals like lithium, cobalt, nickel, and manganese for new batteries.
Chinese researchers found a new way to do this. They use a hydrometallurgical process, which means breaking down materials in liquid. Unlike older methods with acids or ammonia, this one uses a neutral solution. Neutral means not too acidic or basic, making it safer and greener.
This work is published in Angewandte Chemie. The researchers mixed spent battery parts with iron salt, sodium oxalate, and glycine, an amino acid. This creates tiny “micro batteries” inside the solution. These micro batteries help pull apart the battery’s cathode, a part called NCM made of lithium, nickel, cobalt, and manganese. The iron salt forms a coating on NCM particles. This coating acts like an anode, while NCM acts as a cathode. An anode and cathode are parts of a battery that move electrons. This setup, called the battery effect, speeds up the process.
How the process works
The reaction turns iron(II) ions into iron(III) ions and breaks NCM into pieces. Lithium, nickel, cobalt, and manganese ions then float into the solution. Glycine grabs these ions, forming complexes, which are like chemical cages. Glycine also keeps the solution neutral by balancing its pH, a measure of acidity. In just 15 minutes, the method pulls out almost all the lithium and most of the other metals. It gets 99.99% of lithium, 96.8% of nickel, 92.35% of cobalt, and 90.59% of manganese.
This method beats older ones. It uses less energy and costs less. It makes almost no harmful gases. The leftover glycine can even become fertilizer. The researchers say this could lead to big recycling projects. Their trick with micro batteries and glycine makes recycling safer and more efficient.
The Independent covers this research in an article titled "Battery breakthrough as 99.99% of lithium extracted from old cells."