Electrochemical “bath” could bring spent lithium-ion batteries back to life, cut cost of recycling in half

Researchers from Cornell University in New York believe they have found a way to recover almost the full life of lithium-ion batteries by using an electrochemical solution to regenerate a battery’s electrodes.

The potentially game-chaging process could theoretically cut the cost of battery stewardship by 56 per cent compared to current recycling methods and would also be more environmentally friendly, reducing harmful air pollutants and water use.

As batteries rapidly become an integral part of society, whether in mobile phones or electric vehicles or home and utility-scale energy storage, the race for materials to meet demand has caused prices to skyrocket as supply diminishes.

Various battery recycling methods have been proposed and demonstrated – and are even beginning to be scaled up to full commercialisation – but the battery industry predominantly relies on what Cornell researchers describe as a linear “take-make-dispose approach” that invariably sees batteries end up in landfills.

Battery recycling methods are evolving to deconstruct spent batteries and reuse their base materials, but this requires significant investment in the infrastructure and processes needed to shred batteries down and separate the resulting “black mass” to their base components, before refabrication.

Cornell researchers, however, have developed what they believe is a more efficient and cost-effective way to recover almost the full life of lithium-ion batteries after they are spent.

In findings published in the journal Energy and Environmental Science last month, the researchers introduced a new method that uses an electrochemical solution to regenerate their electrodes.

The so-called direct electrode-to-electrode regeneration (DEER) allows these batteries to regain up to 95 per cent of their original power and last longer when reused.

Specifically, DEER involves removing a spent battery’s individual electrodes and attaching them to the current collector before placing them in a separate cell that contains an electrochemical solution: 1,3-dimethyl-2-imidazolidinone.

This solution dissolves the thick insulating layer, known as the solid electrolyte interphase, that builds up gradually between the cathode and anode during the battery’s charge and discharge cycle, gradually diminishing its capacity over time.

The Cornell researchers are currently using the new process on electric vehicle batteries which have a state of health between 70 to 80 per cent. The next step is to demonstrate DEER on industrial batteries as well as target other forms of battery degradation, such as lithium loss.

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