Lithium-ion batteries are currently performing the best, but they have many limitations and pose environmental concerns. However, crab shells are postulated as a solution to some of them.
We always say it: the electric car has become the champion of climate change and one of the main pillars on which decarbonisation is based. But, as we also remind from time to time, the plan to base all of this on the lithium ion batteries current poses other problems that cannot be ignored.
Current batteries use expensive, limited, toxic and flammable components. This makes producing a current lithium-ion battery expensive and also questionable from a sustainability standpoint.
Zinc chitosan battery maintains 99.7% energy efficiency after 1,000 charge cycles
To manufacture a battery of this type, among other things, an anode, a cathode and an electrolyte that allows the transfer of electrons between the first two are needed. The electrolyte is toxic and flammable, so science works to find much safer and more sustainable alternatives.
crab shells
Well, scientists University of Maryland have created a zinc battery with a biodegradable electrolyte from an unexpected source: crab shells.
The discovery has been featured in an article in Matter magazineand describes how to create a gel electrolyte made from a biological material with many natural sources called chitosan.
“Large quantities of batteries are being produced and consumed, which increases the possibility of environmental problems”recalled lead author and professor of materials science and engineering Liangbing Hu, director of the Center for Materials Innovation at the University of Maryland.
For example, polypropylene and polycarbonate separators, which are widely used in lithium-ion batteries, will take hundreds or thousands of years to degrade”insists Liangbing Hu, who works with the other study authors affiliated with the University of Houston and UMD’s Department of Materials Science and Engineering.
Advantages of chitosan electrolyte
Being biodegradable, this chitosan-based electrolyte makes it possible for microbes to break down up to two thirds of the total battery and in only 5 months.
In addition, the study has revealed that the battery of zinc and chitosan maintains a 99.7% energy efficiency after 1,000 charge cycles“so it becomes a viable option for renewable energy storage,” says Hu.
«The most abundant source of chitosan is the exoskeletons of crustaceansincluding crabs, shrimps and lobsters, which can be easily obtained from shellfish waste,” Hu adds.
Chitosan, combined with zinc, also allows a cheaper and safer battery. “Zinc is more abundant in the earth’s crust than lithium”Hu says. “Generally speaking, well-developed zinc batteries are cheaper and safer.”
Hu reports that his team will continue to work on making batteries that are even more environmentally friendly, including throughout the manufacturing process.
“In the future, I hope that all battery components will be biodegradable”Hu says. “Not only the material itself, but also the biomaterial manufacturing process.”
Font: University of Maryland
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Photos: Freepik