Scientists hope to use chemicals found in crab and lobster shells to make batteries more sustainable, according to research.
“We believe that both the biodegradability, or environmental impact, and battery performance of a material are important to any product that may be commercialized,” said director of the Center for Materials Innovation at the University of Maryland. said leader Liangbing Hu. Author of papers published in Matter.
As the world moves towards adopting green energy solutions and electric vehicles, the batteries used in such technologies must also be environmentally friendly.
However, the chemicals used in conventional batteries, such as lithium-ion, can take hundreds or thousands of years to decompose. These chemicals are often corrosive and also flammable. In some cases, batteries in consumer gadgets have caught fire on airplanes and have caused fires at waste and recycling sites.
Researchers in Maryland have developed a battery that stores energy using products derived from crustacean shells.
Crustaceans, such as crabs, shrimp and lobsters, have an exoskeleton made up of cells containing chitin, a type of polysaccharide that makes their shells hard and tough. This valuable substance is abundant in nature, even found in fungi and insects, but is usually discarded as food waste from restaurants and by-products of the food industry. I have been researching its uses. For example, biomedical engineering such as wound dressings and anti-inflammatory treatments, and now electrical engineering.
Through chemical treatment and the addition of aqueous acetic acid, chitin is finally synthesized into a strong gel film and used as an electrolyte in batteries. The electrolyte is the liquid, paste, or gel in the battery that helps ions (charged molecules) move between one end of the battery and the other, thus storing energy.
By combining this chitosan electrolyte with zinc, a natural metal that is increasingly used to make cheap and safe batteries, Hu’s team was able to create a renewable battery.
The battery maintains 99.7% energy efficiency even after 1,000 battery cycles, equivalent to approximately 400 hours. This means it can be charged and discharged quickly without significantly impacting performance. “It is not trivial for batteries to operate at high current densities. The displayed performance suggests the merits of chitosan-based materials in this work.”
The batteries are not combustible and two-thirds of the chitosan-made batteries decompose in the soil in just five months thanks to microbial decomposition, leaving recyclable zinc. Antonio J. Fernandez Romero, professor of materials science for energy production at the University of Cartagena in Spain, who was not involved in the study, said these were “outstanding properties.”
“Designing new batteries that are environmentally friendly, inexpensive and produce high discharge capacity is one of the key areas that must be developed in the next few years.” The system appeared to work quite well, but added that it needs to be tested at a larger scale and under commercial use conditions.
According to Hu and the study authors, this design could pave the way for the development of high-performance, sustainable batteries for green energy storage.
Graham Newton, professor of materials chemistry at the University of Nottingham, said: He is an expert on sustainable batteries and researches how to improve them.
So far, according to Newton, the chitosan-zinc battery results are promising. “Several examples of such batteries have been commercialized and tested as stationary energy storage systems,” Newton said. “There are still many challenges in developing zinc-ion batteries, but basic research like this is very important.”