University of Birmingham researchers say they have developed a method to upcycle end-of-life batteries into materials that can be used for “next generation” electric vehicle battery cathodes.
The team at the University of Birmingham used the recovered material from end-of-life electric vehicle (EV) batteries to synthesize compounds with a disordered rock salt (DRX) structure. DRX materials can increase the capacity of the cathode, which allows the development of higher energy density rechargeable Lithium-ion batteries, the University says.
The cathode is the part of batteries that supply electrical current. The University says the cathode is the primary limitation for achieving the high-energy, low-cost lithium-ion (LI) batteries needed for the transition to zero emissions at the tailpipe.
The research team led by Professor Peter Slater believe this is the first time such materials have been made from recycled EV battery feedstock. The University says the results of electrochemical testing showed comparable performance to materials prepared from conventional high-purity reagents.
Researchers at the University of Birmingham are aiming to upcycle recovered battery materials, so the waste streams from current EV batteries can be used to manufacture new high-performance batteries.
The research team is working on a number of methods for recycling and upcycling battery cathode materials.
The research, which is published in ChemRxiV, is a development of previous work that demonstrates ascorbic acid (Vitamin C) can be used as a leaching agent to replace the need for hazardous chemicals in cathode recycling, the University says.
The University says researchers used citric acid (a natural component of citrus fruits) as a leaching agent, which they applied to cathodes from an end-of-life Gen 1 Nissan Leaf (2011 model, 40,000 miles), and used the recovered lithium manganese oxide as a starting point for synthesis. They then used the recovered material to synthesize compounds with a DRX structure.
Professor Slater commented: “The challenge is no longer about recycling. Battery chemistry has moved on considerably in the last decade, and, as first-generation EV batteries reach the end of their lives, their components need to be upcycled to deliver chemistries that can be reused in the newer batteries.
“The research team is working on a number of methods for recycling and upcycling battery cathode materials, and is looking for long-term partners for pilot studies, deliver technologies to existing infrastructure, or collaborate on further research to develop novel approaches.”