Soon, batteries that 'breathe'

Researchers have made new progress in developing a "breathing" battery that has the potential to replace the lithium-ion technology of today's electric vehicles (EVs).

They presented their work at the 247th National Meeting and Exposition of the American Chemical Society (ACS), the world's largest scientific society, taking place at the Dallas Convention Center and area hotels.

"Lithium-air batteries are lightweight and deliver a large amount of electric energy," Nobuyuki Imanishi, Ph.D said.

"Many people expect them to one day be used in electric vehicles," Imanishi said.

The main difference between lithium-ion and lithium-air batteries is that the latter replaces the traditional cathode - a key battery component involved in the flow of electric current - with air. That makes the rechargeable metal-air battery lighter with the potential to pack in more energy than its commercial counterpart.

While lithium-air batteries have been touted as an exciting technology to watch, they still have some kinks that need to be worked out. Researchers are forging ahead on multiple fronts to get the batteries in top form before they debut under the hood.

One of the main components researchers are working on is the batteries' electrolytes, materials that conduct electricity between the electrodes. There are currently four electrolyte designs, one of which involves water. The advantage of this "aqueous" design over the others is that it protects the lithium from interacting with gases in the atmosphere and enables fast reactions at the air electrode. The downside is that water in direct contact with lithium can damage it.

The battery showed a lot of promise, with high conductivity of lithium ions, and the ability to discharge and recharge 100 times. In addition to powering EVs, lithium-air batteries could one day have applications in the home, thanks to their low cost.

Power output remains a big hurdle, but Imanishi said his group is committed to honing this approach, as well as exploring other options, until lithium-air becomes a commercial reality.