Scientists from several academic institutions in China, have succeeded in leaching 99% of lithium from used batteries. The method they used is if anything more remarkable, especially the ‘micro batteries’ they deployed. We summarize the basic principles here, but append two links if you would like to explore this topic further.
Leaching 99% of Lithium at Neutral pH Level
Lithium-ion batteries contain scarce materials, such as lithium, cobalt, nickel, and manganese. Recycling factories need to recover these metals, for production of fresh batteries. Current hydrometallurgical methods depend on acid or ammonia leaching processes.
However, we should not continue endlessly following these methods, on account of their environmental and safety impacts. We are under the impression that a pH neutral process would be a distinct improvement.
The new process for leaching 99% of lithium from used batteries, is the brainchild of Chinese scientists at Central South University, Guizhou Normal University, and National Engineering Research Central of Advanced Energy Storage.
Their revised procedure followed hydrometallurgical principles, in that it used a neutral solution to retrieve lithium metal from scrap batteries. Although the researchers added a solid-to-solid reduction ‘battery effect’, plus added amino acid glycine.
‘Micro Batteries’ Break Up Cathode Material in Situ
The researchers combined lithium-coated nickel cobalt manganese oxide particles (NCM), with salt, sodium oxalate, and amino acid glycine in a neutral liquid. This generated a thin layer of iron oxalate on the particles.
The ‘shell’ that resulted performed the role of an anode, while the NCM core acted as cathode, allowing easy electron transfer thanks to direct contact. The resulting ‘battery effect’ drove an electrochemical reaction that decomposed the NCM layers.
The lithium, nickel, cobalt, and manganese ions released into the solution, where they were clustered in complexes in the glycine. The researchers succeeded in leaching 99% of lithium from used batteries after 15 minutes, plus more than 90% of the nickel, cobalt and manganese.
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Preview Image: Method For Recycling L-Ion Batteries
