Rechargeable zinc-air batteries zero in on lithium

Sydney, Australia

Sounds promising, but can these batteries make the leap from hearing aids to machinery in general? Developments – if any – awaited.

Zinc-air batteries are an enticing prospect thanks to their high energy density and the fact they’re made with some of the most common materials on Earth, says New Atlas.

Unfortunately, those advantages are countered by how difficult it is to recharge these cells. Now, a team at the University of Sydney has created new catalysts out of abundant elements that could see rechargeable zinc-air batteries vying with lithium-ion batteries in mobile devices.

The chemical reaction that drives zinc-air batteries to produce electricity comes from the air around the cell. They essentially breathe in oxygen that interacts with a carbon cathode to produce hydroxyl, which in turn interacts with a zinc anode to generate an electric current. Using air as a reactant allows the battery to cram in more zinc, increasing the energy density and making the battery fairly lightweight and safe.

But the problem is that once the zinc anode has been oxidized, it isn’t much use. These batteries can be mechanically “recharged” by replacing the zinc component completely, or by using electrocatalysts made from rare-earth minerals that reduce oxygen while discharging the battery, and generate it while recharging.

“Up until now, rechargeable zinc-air batteries have been made with expensive precious metal catalysts, such as platinum and iridium oxide,” says Yuan Chen, lead author of the study. “In contrast, our method produces a family of new high-performance and low-cost catalysts.”

Continued here.