Sustainable and long-lasting batteries are the great challenge of the industry. And it has a new ally: crabs

We are increasingly using electric vehicles and renewable energies. And that’s great from an environmental point of view. After all, these are more sustainable and environmentally friendly options than, for example, combustion cars. The problem is that this rising demand translates into a greater volume of batteries, which is no longer such good news in environmental terms. The typical “undress a saint to dress another”, as the proverb would say.

A group of researchers from University of Maryland Materials Innovation Center He has just discovered that this dilemma could be solved thanks to some common and unexpected allies: crabs and lobsters. Yes, the same ones you eat at seafood restaurants.

The key is in their shells, exoskeletons rich in chitin, a polysaccharide that we can also find in fungi and certain insects. Through it, scientists can in turn derive chitosan, a valuable material —as scientists have just verified— for batteries.

The other advantage of seafood

The normal thing when we eat some crabs or some good crabs is that we end up throwing their shells in the garbage and, with them, an important source of chitin. In Maryland they have opted for put it to a different use: Instead of discarding it, scientists have worked with it, adding an aqueous solution of acetic acid to synthesize it into a gel membrane that can be used as an electrolyte. Later they combined it with zinc to make batteries.

And not just any kind of batteries.

Its prototypes have shown to have a more than remarkable consistency, with an energy efficiency that remained at 99.7% past even a thousand cycles. The most important thing, however, is what happens when we want to get rid of them. The researchers estimate that two-thirds of their batteries they are biodegradable and in fact they have verified how, once discarded, they spent five months in contact with the ground for the electrolyte to decompose. All thanks to microbial degradation. The only thing left were scraps of recyclable zinc.

This peculiarity supposes a crucial difference with respect to conventional models, such as lithium-ion ones, in which chemicals are used that can take centuries to decompose.

“Polypropylene and polycarbonate separators, which are widely used in lithium-ion batteries, take hundreds or thousands of years to degrade and increase the environmental burden,” scientists explain. Researchers are already working to make 100% of their batteries biodegradable and even, beyond the materials, the battery itself. fabrication process be more ecological.

Thanks to its characteristics, the new electrolyte could give a boost to zinc ion batteriesan alternative to lithium-ion that now faces a serious problem: the effect of corrosion. In addition to alleviating this handicap, chitosan offers some extra important advantages, such as the fact that it is an economical, safe material that is easy to access.

Cover Image | Jim Strasma (Unsplash)