Research in lithium-ion batteries has opened up a plethora of possibilities in the development of next-generation batteries. In particular, the metal-air batteries with significantly greater energy density close to that of gasoline per kilogram, has recently been acknowledged and invested by world's leading companies, like IBM.

A recent study ("A Highly Efficient and Robust Cation Ordered Perovskite Oxide as a Bifunctional Catalyst for Rechargeable Zinc-Air Batteries") has presented novel catalyst to accelerate the commercialization of metal-air batteries.

This breakthrough has been jointly led by Professor Guntae Kim and Professor Jaephil Cho in the School of Energy and Chemical Engineering at UNIST in collaboration with Professor Yunfei Bu from Nanjing University of Science and Technology, Nanjing, China. Their new catalyst possesses the structure of nanofiber-based perovskite materials and exhibits excellent electrochemical performance, close that of today's precious metal catalysts, yet still inexpensive. A metal-air battery is a type of fuel cell or battery that uses the oxidation of a metal with oxygen from atmospheric air to produce electricity. It is equipped with an anode made up of pure metals – like lithium or zinc – and an air cathode that is connected to an inexhaustible source of air. The catalysts in the air cathode aids the electrochemical reaction of the cell with oxygen gas. Metal-air batteries have attracted significant research attention as the new generation of high-performance batteries as they the advantages of (1) simple structure, (2) extremely high energy density, and (3) a relatively inexpensive production.

The currently existing metal-air batteries use rare and expensive metal catalysts for their air electrodes, such as platinum (Pt) and iridium oxide (IrO2). This has hindered its further commercialization into the marketplace.

In the study, Professor Kim and his research team have developed a new catalyst, using the cation ordered double perovskite with high electrical conductivity and catalyic performance. They prepared a series of PrBa0.5Sr0.5Co2-xFexO5+δ (x = 0, 0.5, 1, 1.5, and 2, PBSCF) and determined the optimum cobalt (Co) and iron (Fe) contents through electrochemical evaluation.