England (Commonwealth Union) _ Scientists are looking into a variety of different chemistries for large-scale batteries that could be used for grid storage in the quest to be able to store renewable solar and wind energy on the electric grid to be used at times when the sun isn’t shining and the wind isn’t blowing.
The aqueous zinc ion battery (AZIB), a candidate for this type of battery chemistry, has been identified as a promising grid storage technology that can aid in maximizing the benefits of renewable energy sources. Zinc, a vital sustainable metal, is used as the anode material in the cell, which is the cornerstone of the affordability and safety of AZIBs.
Zinc is far more naturally plentiful and highly compatible with water than lithium, which makes it possible to employ cost-efficient, nonflammable, aqueous-based electrolytes directly. However, in a recent study, scientists from the University of Waterloo who are a part of the Joint Center for Energy Storage Research based at the Argonne National Laboratory of the U.S. Department of Energy (DOE) have suggested that many claims in the open literature have been inadvertently overestimated and that zinc-ion batteries still face many difficulties.
The cathode side continues to provide difficulties. University of Waterloo Professor Linda Nazar asserts that the aqueous-based electrolyte’s water molecules have the ability to spontaneously split into hydroxide ions and protons. The leftover hydroxide ions have the opportunity to join with zinc while the protons compete with the zinc ions as they shuttle back and forth into the cathode materials of the battery (a process known as intercalation). Layered zinc double hydroxides are the products of that reaction, according to Professor Nazar, which precipitate on the cathode surface and “take zinc out of the equation, insulating the surface in an extremely detrimental side reaction”.
