Monash Uni on the brink of zinc-air battery technology breakthrough

Engineers from Monash University have made a breakthrough that could enable zinc-air battery technology to move beyond small devices and into large-scale, high-power applications such as electric vehicles and grid storage.

The new catalyst design promises increased power, longer battery life and lower costs, using materials that are abundant and safe.

Zinc-air batteries work by oxidising zinc with oxygen from the air, making them attractive for their high theoretical energy density, safety, and the fact that zinc is less expensive than lithium or sodium.

Currently, zinc-air batteries are mainly used in small devices such as hearing aids due to challenges in scaling up. The main obstacle has been the slow and inefficient oxygen reactions inside the battery, which limit performance and reduce battery lifespan.

Monash researchers overcame this by using a heat treatment to convert a three-dimensional carbon material into ultra-thin sheets. They then added individual cobalt and iron atoms onto the carbon framework, creating a unique catalyst that accelerates oxygen reactions in the battery, boosting efficiency and output.

PhD student Saeed Askari, co-lead author of the study published in Chemical Engineering Journal, explained: “By engineering cobalt and iron as individual atoms on a carbon framework, we achieved record-breaking performance in zinc-air batteries, showing what is possible when catalysts are designed with atomic precision.”

Computer simulations revealed that the cobalt-iron atom pairs, together with nitrogen atoms doped into the carbon sheets, enhance charge transfer and optimise reaction kinetics – effectively solving one of the biggest bottlenecks in rechargeable zinc-air batteries.

The technology outperformed commercial catalysts made from costly metals such as platinum and ruthenium, achieving power density of 229.6 milliwatts per cm² and energy density of 997Wh per kilogram, maintaining stable performance for 74 days and more than 3500 charging cycles.

Senior lecturer and co-lead researcher Dr Parama Banerjee said: “Running a rechargeable zinc-air battery continuously for more than two months is a milestone for the field. It demonstrates that this technology is ready to move beyond the laboratory and into practical applications.”