Although the electric car has been identified as the most effective solution to the problem of pollution associated with transport, its detractors have a huge target in the recycling of batteries.
And it is that the recycling of these components mainly constituted by expensive and / or polluting elements such as lithium and its different variants resulting from the combination of aluminum, cobalt, nickel or magnesium, among others, remains a pending issue for several reasons.
The first is that it is still a very expensive process and the second is that it is not effective enough to guarantee correct use of raw material once the battery has reached the end of its useful life. Something that, in the case of electric vehicles, arrives between eight and 12 years after the car was released.
Avalanche of batteries in 10 years
The lithium ion batteries They are currently a basic element of society, since they are not only present in electric vehicles, but in all electronic devices that we use every day, including mobile phones. It is not difficult to imagine, therefore, that in 10 years the need to meet the demand for recycling will be a priority issue.
It is also obvious that, with current recycling processes, the world is not prepared to manage the two million tons of electric vehicle batteries which is calculated to occur annually at that time. And we are only talking about the waste generated by electric mobility, a sector that is booming but which is still far from beginning its true consolidation in the world market.
Foam floatation
The scientific panorama is fully aware that the technology associated with electric mobility has a lot of potential and a long way to go, which is why many institutions and companies have opted to focus their efforts on research related to it.
This is the case of scientists from ReCell Center, America’s first advanced battery recycling research and development center based at the Department of Energy (DOE) Argonne National Laboratory who, in collaboration with Michigan Technological University (MTU), have made a fundamental discovery that removes one of the biggest obstacles to making the large-scale lithium-ion battery recycling is economically viable.
The foam flotation technique solves the main problem of every recycler, separate the materials that make up the cathode, that is, the positively charged electrode. This is tricky because the cathodic materials in EV batteries vary by car manufacturer and year of production, so a recycler starts working with a mixture of lithium metal oxides (lithium cobalt oxide, lithium oxide of lithium nickel manganese cobalt, lithium nickel aluminum oxide, lithium iron phosphate, etc.) and try to separate each of them so that those materials are reused. That once impossible task suddenly seems doable.
Used for many years by the mining industry to separate and purify minerals, foam flotation separates materials into a flotation tank depending on whether they repel water and float, or absorb water and sink. Cathode materials generally sink, which makes them difficult to separate from each other.
“That’s true for Lithium Nickel Manganese Cobalt Oxide (NMC111) and Lithium Manganese Oxide (LMO), two common EV battery cathode materials that the ReCell team used in their experiments,” notes the information provided. by Argonne National Laboratory. ‘What the researchers found was that separation can be achieved by making one of the cathode materials, NMC111, float through the introduction of a chemical that makes the target material repel water ».
Once the materials were separated from the cathode, the researchers determined through testing that the process had a negligible impact on the materials’ electrochemical performance. They both also had high purity levels of at least 95%, which in practice allows them to be reused for new car batteries thanks to their high purity.
There is still way to go
The ReCell discovery promises to have far-reaching implications:
- Reduce the cost of recycling lithium-ion batteries
- Stimulate the growth of a profitable recycling market for lithium-ion batteries at the end of their useful life
- Reduce the cost of electric vehicles for both producers and consumers
However, there is still some way to go before turning this technique into a viable large-scale solution, as ReCell itself admits. “For now, the ReCell Center team is focused on creating, step by step, a complete lithium-ion battery recycling process that is economically viable. Only then will it be widely adopted ».
‘Whatever method is used to do this recycling, the recycler has to be able to benefit from it »says Jessica Durham, Argonne materials scientist and study co-author. “We are joining the steps knowing that, in the end, the total process will have to be profitable.”