Earth could have more sustainable batteries with the help of an unusual resource: Crustaceans.
In an article published last week in the journal Matter, researchers say they’ve made a biodegradable battery using a substance found in crab and lobster shells.
An important part of the way batteries work is the electrolyte substance, which sits between the two electrical terminals at each end and helps ions move back and forth between the positively and negatively charged terminals to generate electricity. Conventional batteries use lead or lithium for this purpose.
We’ll need huge amounts of batteries to get rid of fossil fuels, but traditional electrolytes bring with them a host of new problems: They’re incredibly complex to recycle, electrolytes aren’t biodegradable, and they’re dangerous in their own right. Sometimes they can explode or cause a fire. In the case of lithium batteries, massive mining applications are required to get enough lithium for our projected energy needs, which is damaging to the environment.
Crabs and lobsters have a substance called chitin in their exoskeletons that helps keep their shells firm and strong. Chitin can also be made into a derivative called chitosan, which the researchers combine with zinc to create a new electrolyte to power the battery. They are said to continue to work efficiently even after 400 hours of use. What’s more, unlike conventional battery electrolytes, this substance breaks down in the soil and leaves behind zinc, which can be recycled in about five months.
“In the future, I hope all components in batteries will be biodegradable,” said Liangbing Hu, director of the Center for Materials Innovation at the University of Maryland, adding: “Not only the material itself, but also the manufacturing process of biomaterials will be environmentally responsible.”
Unfortunately, even if this production was accomplished in the lab, it doesn’t mean all our dirty battery problems are solved. “When you develop new materials for battery technologies, there is a significant gap between promising lab results and a demonstrable and scalable product,” says Graham Newton, professor of materials chemistry at the University of Nottingham, who was not involved in the study.
Still, Newton said the work was encouraging: “There are still a few challenges to be faced in the development of zinc-ion batteries, but fundamental work like this is extremely important.”