Researchers from the University of Maryland’s Center for Materials Innovation have developed a new zinc battery with an electrolyte extracted from a crab shell, according to a press release published by EurekAlert on Thursday.
The electrolyte is made from chitosan, a chemical derivative of Chitin found abundantly in crab shells. Since chitosan is biodegradable, two third of the battery will be degraded naturally without leaving any harmful products.
According to the study, the battery has an energy efficiency of 99.7 percent after 1000 battery cycles, making it a viable option for storing energy generated by wind and solar for transfer to power grids.
In this present study, the scientists relied on crustacean exoskeletons — shells of crabs, lobsters, and shrimps — easily obtained from seafood waste. They found a naturally occurring substance called chitosan — presently used in agriculture as a biopesticide, in winemaking as a fining agent, and in medicine as a component for bandages and as a drug agent — to be useful in the development of alternate materials for batteries. The scientists developed the substance into a gel electrolyte — that circumvented the stability issue with earlier models of zinc-air batteries — and made partly biodegradable batteries whose ends were made of zinc.
On testing these new batteries, scientists found that they demonstrated impressive performance and exceptional cyclical stability, i.e. the cycle life or the number of charge and discharge cycles that a battery can go through without losing its performance power. These batteries are also safer for the environment than lithium-based batteries. The degradable components in the present chitosan-zinc battery can degrade in five to six months, while the zinc itself can be recycled. “…the chitosan-Zn electrolyte is non-flammable and biodegradable, making the proposed Zn-metal battery appealing in terms of safety and sustainability, demonstrating the promise of sustainable biomaterials for green and efficient energy-storage systems,” the researchers write.
The researchers plan to work on making batteries even more environmentally friendly, from the manufacturing process onwards.