It seems like an unlikely process — transforming a pile of shells from a gusto-driven, finger-licking crab feast into a sustainable battery to power future electric vehicles. But it may be possible.
In a paper published in the journal Matter, University of Maryland researchers say they’ve made a biodegradable battery with a substance found in crab shells.
Demand for renewable energy and electric vehicles is high, but the batteries to power the EVs aren’t always sustainable themselves.
“Vast quantities of batteries are being produced and consumed,” says lead author Liangbing Hu, director of the University of Maryland’s Center for Materials Innovation. Some of the materials used in lithium batteries “take hundreds of thousands of years to degrade and add to environmental burden.”
According to Science Daily, “Batteries use an electrolyte to shuttle ions back and forth between positively and negatively charged terminals. An electrolyte can be a liquid, paste or gel, and many batteries use flammable or corrosive chemicals for this function.”
The new battery uses a gel electrolyte made from a biological material called chitosan.
“The most abundant source of chitosan is the exoskeletons of crustaceans, including crabs, shrimps and lobsters, which can be easily obtained from seafood waste,” Hu says. “You can find it on your table.”
Hu estimates the biodegradable electrolyte could be broken down by microbes within five months. In addition, the batteries would use zinc, which is far more biodegradable than than lead or lithium.
“Zinc is more abundant in earth’s crust than lithium,” Hu says. “Generally speaking, well-developed zinc batteries are cheaper and safer.”
Hu and his team plan to continue work to minimize the burden on the environment.
“In the future, I hope all components in batteries are biodegradable,” he says. “Not only the material itself, but also the fabrication process of biomaterials.”