The world could create more sustainable batteries with an unusual source: crustaceans. In a paper published this week in the journal Matter, researchers say they have made a biodegradable battery with a substance found in crab and lobster shells.
A crucial part of the way that batteries work is an electrolyte substance that sits between the two electric terminals at either end, which helps ions move back and forth between the positively and negatively charged terminals to generate electricity. Conventional batteries rely on lead or lithium (e.g., lead-acid batteries and lithium-ion batteries), but these batteries come with a host of issues.
We’re going to need a huge amount of batteries to move off of fossil fuels, but traditional electrolyte substances bring with them a host of new issues: They can be incredibly complex to recycle, the electrolytes are not biodegradable, and they can be dangerous in their own right, sometimes exploding or causing fires. In the case of lithium batteries, there’s also an issue with the destructive mining practices the world may have to engage with in order to obtain enough lithium for our projected energy needs.
Enter crustaceans. Crabs and lobsters have a material in their exoskeletons called chitin, which helps keep their shells tough and strong. Chitin can also be made into a derivative called chitosan, which researchers combined with zinc to create a new electrolyte substance to power a battery that they say remains almost entirely energy efficient after 400 hours of use. What’s more, unlike traditional battery electrolytes, this crab goo will break down in soil in about five months, leaving zinc—that can be recycled—behind.
“In the future, I hope all components in batteries are biodegradable,” lead author Liangbing Hu, director of the University of Maryland’s Center for Materials Innovation, said in a press release. “Not only the material itself but also the fabrication process of biomaterials.”
If any crabs reading this are getting nervous, don’t worry—there’s other sources of chitin in the world. Crustacean shells are particularly chitin-rich, but chitin can also be found in the walls of fungi and parts of squid.
Alas, one laboratory test of a biodegradable lobster energy pack does not mean that all our dirty battery problems are solved. “When you develop new materials for battery technologies there tends to be a significant gap between promising lab results and a demonstrable and scalable technology,” Graham Newton, a professor of materials chemistry at the University of Nottingham who was not involved in the study, told the Guardian.
Still, Newton said that the study was encouraging. “There are still quite a few challenges to be met in the development of zinc ion batteries, but fundamental studies such as this are hugely important,” he said. We can’t be too crabby about that.