Researchers have developed a zinc-air battery that may eventually replace costly lithium-ion batteries.

Stanford scientists created the battery which is less costly, more energy-dense and safer than the traditional lithium-ion kind.

"There have been increasing demands for high-performance, inexpensive and safe batteries for portable electronics, electric vehicles and other energy storage applications," said study author Hongjie Dai, a professor chemistry at Stanford.

"Metal-air batteries offer a possible low-cost solution."

The zinc-air batteries blend atmospheric oxygen with zinc in a liquid alkaline electrolyte, while generating electricity.

The byproduct is zinc oxide. Oxygen and zinc are replenished during recharging.

The batteries are lower in cost as they use zinc instead of expensive platinum.

They are also safer because of the non-flammable electrolytes.

Lithium-ion has a nasty habit of catching fire - just ask the makers of the Boeing 787 jet.

There are still challenges explains the study author.

"It remains a grand challenge to develop electrically rechargeable batteries, with the stumbling blocks being the lack of efficient and robust air catalysts, as well as the limited cycle life of the zinc electrodes," said Dai.

The findings were published in the journal Nature Communications.