University of Birmingham (UOB) researchers have announced a new approach for recycling the battery cathode in end-of-life electric car batteries, which the university describes as the battery’s highest-value component.
The UOB says the method is less energy-intensive and uses less hazardous chemicals than current recycling methods. The novel method uses organic acid, such as ascorbic acid (Vitamin C), as a leaching agent and has been tested on cathode material from a first-generation Nissan Leaf battery cell that had powered 40,000 miles of driving.
The research team chose a battery from a Nissan Leaf as this car was the first mass-market electric vehicle, so both the cars and batteries will be among the first to enter recycling chains.
“Our method will reduce the cost and number of steps to recover cathode materials, so they can be remanufactured and put back into new batteries, with minimal environmental footprint,” Professor Peter Slater said.
The results of this testing, published in ChemRxiV, demonstrated that ascorbic acid selectively leaches low-value electrode material (lithium manganese oxide) and leaves the higher-value nickel and cobalt-based material in a solid state, from which it can be directly recycled.
Our method removes the low-value material, while leaving the high-value material in a solid state, so it can be directly recycled.
The new leaching method was invented by Professor Peter Slater, Professor Paul Anderson, and Dr Laura Driscoll from Birmingham’s School of Chemistry and has been patented by the University of Birmingham Enterprise.
Their research is part of the ReLiB (Recycling and Reuse of EV Lithium-ion Batteries) project, a multi-institution consortium of researchers funded by the Faraday Institution and led by the UOB, which aims to improve the “speed, economics and the environmental footprint” of recycling processes.
Professor Slater commented: “Battery chemistry, and cathode chemistry in particular, is constantly evolving to meet the demand for greater energy density.
“However, battery recycling has remained relatively static and has focused on breaking down the cathodes into their individual element components particularly when recycling mixed chemistries, which loses a lot on the internal value of the cathode material.
“Our method removes the low-value material, while leaving the high-value material in a solid state, so it can be directly recycled, maintaining its high value.”
The UOB says the research team is now working on scaling up the new approach and is looking for long-term partners for pilot studies.
