Now, high-efficiency zinc-air batteries that are cheaper to make

Washington, May 30 (ANI): Scientists have created an advanced zinc-air battery, which has higher catalytic activity and durability than the ones that are constructed of costly platinum and iridium catalysts.

The results could lead to the development of a low-cost alternative to conventional lithium-ion batteries widely used today.

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

He said that metal-air batteries offer a possible low-cost solution.

According to Dai, most attention has focused on lithium-ion batteries, despite their limited energy density (energy stored per unit volume), high cost and safety problems.

"With ample supply of oxygen from the atmosphere, metal-air batteries have drastically higher theoretical energy density than either traditional aqueous batteries or lithium-ion batteries," he said.

"Among them, zinc-air is technically and economically the most viable option."

"Zinc-air batteries are attractive because of the abundance and low cost of zinc metal, as well as the non-flammable nature of aqueous electrolytes, which make the batteries inherently safe to operate," Dai said.

He asserted that primary (non-rechargeable) zinc-air batteries have been commercialized for medical and telecommunication applications with limited power density.

"However, 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," he said.

Recently, his group has developed a number of high-performance electrocatalysts made with non-precious metal oxide or nanocrystals hybridized with carbon nanotubes.

These catalysts produced higher catalytic activity and durability in alkaline electrolytes than catalysts made with platinum and other precious metals.

"We found that similar catalysts greatly boosted the performance of zinc-air batteries," Dai said.

"A combination of a cobalt-oxide hybrid air catalyst for oxygen reduction and a nickel-iron hydroxide hybrid air catalyst for oxygen evolution resulted in a record high-energy efficiency for a zinc-air battery, with a high specific energy density more than twice that of lithium-ion technology," he added.

The results have been published in the online edition of the journal Nature Communications. (ANI)