New Swedish study finds more efficient way to recycle EV batteries

Researchers at Sweden’s Chalmers University of Technology have developed a new and efficient way to recycle metals from spent electric vehicle batteries using oxalic acid, a naturally occurring organic acid found in plants such as rhubarb and spinach.

The new method allows for the recovery of 100 percent of the aluminium and 98 percent of the lithium in spent EV batteries while minimising the loss of other valuable raw materials such as nickel, cobalt, and manganese. Using oxalic acid to dissolve the metals is a much safer and more sustainable alternative to the harsh chemicals typically used in battery recycling.

“So far, no one has managed to find exactly the right conditions for separating this much lithium using oxalic acid, whilst also removing all the aluminium. Since all batteries contain aluminium, we need to be able to remove it without losing the other metals,” said Léa Rouquette, a Ph.D. student at the Department of Chemistry and Chemical Engineering at Chalmers.

In existing hydrometallurgy processes, the metals in an EV battery cell are dissolved in an inorganic acid, followed by removing impurities and recovering the metals in powder form. However, this process can lead to the loss of lithium.

The new method reverses the order of this process, recovering the lithium and aluminium first. It reduces the waste of valuable metals and makes it easier to separate them. To achieve these results, the researchers have fine-tuned the oxalic acid separation process’ temperature, concentration and time.

Supporting clean energy transition in Europe

Achieving climate goals requires accelerating the deployment of clean energy technologies, such as wind power and solar panels. EVs are vital to this transition, but they rely on lithium-ion batteries.

The European Union has approved Fit for 55, a new legislation that requires all new passenger cars and light commercial vehicles to have zero carbon dioxide emissions by 2035. The legislation will drive up demand for lithium-ion batteries for EV production.

However, the EU relies heavily on lithium imports, and the recycling rate for lithium-ion batteries is currently lower than one percent, as the Global Electric Vehicle Outlook 2022 reports.

The study by Rouquette, Martina Petranikova, and Nathália Vieceli has been at the forefront of lithium-ion battery recycling for many years. The group has partnered with companies like Volvo Cars, Stena Recycling, the Swedish Energy Agency, Batteries Sweden (BASE), Vinnova, Finnish battery recycler Akkuser Oy, and battery producer Northvolt.

“As the method can be scaled up, we hope it can be used in industry in future years,” research leader Petranikova says. The group has published its findings in the journal Separation and Purification Technology.