The surge in demand for renewables and electric vehicles has triggered a high demand for energy storage batteries, but the batteries themselves are not always sustainable.
Now, scientists have used an unexpected source, crab shells, to create a zinc battery with a biodegradable electrolyte. The study was published September 1 in the journal Matter.
“A large number of batteries are being produced and consumed, which can cause a series of environmental problems. For example, polypropylene and polycarbonate separators, which are widely used in lithium-ion batteries, take hundreds or thousands of years to degrade, increasing the environmental burden. Hu Liangbing, corresponding author of the paper and director of the Center for Materials Innovation at the University of Maryland, said.
Batteries use electrolytes to move ions back and forth between the positive and negative electrodes. Electrolytes can be liquids, pastes, or gels, and many batteries use flammable or corrosive chemicals to achieve this. The new battery can store electricity generated by large-scale wind and solar energy and use a gel electrolyte made from a biomaterial called chitosan.
“Chitosan is a derivative of chitin. Chitin comes from many sources, including the cell walls of fungi, the exoskeletons of crustaceans, and the shell of squid. “The richest source of chitosan is the exoskeleton of crustaceans, including crabs, shrimp and lobsters, which can be easily obtained from seafood waste, even on your table.” ”
The biodegradable electrolyte means that about 2/3 of the battery can be broken down by microorganisms – this chitosan electrolyte can completely decompose within 5 months. This leaves behind a metallic composition, usually recyclable zinc.
“Zinc is more abundant in the earth’s crust than lithium.” Hu Liangbing said, “In general, mature zinc batteries are cheaper and safer. “This zinc-chitosan battery has an energy efficiency of 99.7 percent after 1,000 discharge cycles, making it a viable option for storing and transferring the energy generated by wind and solar energy to the grid.”
Image from the author
The researchers hope to continue working on making more environmentally friendly batteries, including studying more environmentally friendly manufacturing processes. “In the future, I want all the components in the battery to be biodegradable.” Hu Liangbing said, “Not only the material itself, but also the manufacturing process of biological materials. (Source: China Science Daily Feng Weiwei)
Related paper information:https://doi.org/10.1016/j.matt.2022.07.015