Low material cost and environmental protection, what are the challenges for the commercial use of zinc-ion batteries
Zinc-ion batteries have many advantages. There is a lot of zinc in the crust, cheap and mature recycling technology. At the same time, they can also store a lot of electricity. They don’t need to use highly flammable organic solutions as electrolytes. Water-based electrolytes are sufficient, but this technology needs to be commercialized. There is still a long way to go, and now Swiss scientists may have the opportunity to take the first step.
Zinc batteries have many advantages, but also have many disadvantages. When the zinc battery is charged at high voltage, the water-based electrolyte will generate hydrogen gas at the electrode, consume the electrolyte, and make the battery performance decline. This reaction will cause excessive pressure on the battery, which may lead to danger; Another problem is that sharp zinc deposits can also form during battery charging, which can then also puncture the battery separator, risking a short circuit and the battery not being able to continue to function.
Although scientists have also thought about using salt to reduce the water content of water-based electrolytes, the accompanying electrolyte becomes sticky, slowing down the charge and discharge speed, and many of the salts used contain toxic and environmentally harmful ” fluorine”.
That’s why the Swiss Federal Institute of Technology in Zurich (ETH Zürich) teamed up with several research institutions to find the ideal salt concentration for water-based zinc-ion batteries.
Through computer simulations, the team found that the ideal result is not the high concentration previously thought, but a relatively low salt electrolyte, with a ratio of about 5 to 10 water molecules in the positive ion of the salt, and the researchers also used environmentally friendly acetate (Acetate), Dario Gomez Vazquez, the lead author of the paper, said that with the ideal concentration of acetate, the electrolyte consumption can be greatly reduced and zinc dendrites can be prevented, and the battery can be charged and discharged faster through the new method.
At present, the team has tested the new battery in the laboratory, and the next step is to scale up to see if it can be made into a large battery. Ideally, zinc-ion batteries will have the opportunity to be used in grid-level energy storage systems in the future, and can also be applied to solar energy storage at home. energy system.
