The University of Sydney has published a three-stage method to make zinc-air batteries more viable for widespread use. The method is published in "Advanced Materials", a paper by chemical engineering researchers at the University, and proposes a high-performance, low-cost solution to the difficult-to-charge batteries.

Zinc-air batteries, which are powered by zinc metal and oxygen, are difficult to recharge because they lack electrocatalysts, which are required to catalyze the reduction and production of oxygen while the battery is discharging and charging. The new method creates bifunctional oxygen electrocatalysts, which are used to build rechargeable zinc-air batteries, that are produced by simultaneously controlling the composition, size, and crystallinity of metal oxides in inexpensive elements (like iron, cobalt, and nickel) that are then applied to build the batteries.

“Up until now, rechargeable zinc-air batteries have been made with expensive precious metal catalysts, such as platinum and iridium oxide," said Yuan Chen, a professor at the University and lead author of the published method in a news release. "In contrast, our method produces a family of new high-performance and low-cost catalysts.” Tests of this new method proved successful, with fewer than 10 percent of battery efficacy drop over the course of 60 discharging/charging cycles that totaled 120 hours.

Widespread use of zinc-air batteries is a sustainable solution as they are safer, more environmentally friendly, and cheaper alternatives to lithium-ion batteries, and can store up to five times more energy.

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