New catalyst to revolutionise battery technology

Researchers in Australia have discovered a method that enables them to overcome a major drawback of zinc-air batteries, raising hopes for their widespread inclusion in everyday electronics.

Zinc-air batteries are used in hearing aids, railway signal devices and some film cameras. Capable of storing up to five times as much energy as lithium-ion batteries, they are also cheaper to produce due to zinc’s abundance in the Earth’s crust. They are also more environmentally friendly.

A turning point for zinc-air batteries

However, these batteries are very difficult to recharge, due to a lack of electrocatalysts that both reduce and generate oxygen during a charge cycle. Professor Yuan Chen and his research team, from the University of Sydney, have created a three-stage synthesis method to overcome this problem.

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

These catalysts are produced through simultaneously controlling the composition, size and crystallinity of earth-abundant elements’ metal oxides such as iron, nickel and cobalt. Trials of zinc-air batteries with these newly developed catalysts displayed excellent rechargeability. Researchers observed less than a 10% battery efficacy drop over 60 charge and discharge cycles of 120 hours.

Professor Chen said: “We are solving fundamental technological challenges to realise more sustainable metal-air batteries for our society.”

The paper was published in Advanced Materials.