IBM has demonstrated a battery that breathes.

Under the aegis of its Battery 500 project – an effort to build a battery capable of powering a car for 500 miles – Big Blue has designed a battery that produces power by taking in oxygen and then recharges by expelling oxygen. Because its driven by the outside air, such a battery can be significantly smaller and lighter than traditional lithium ion batteries, providing a much longer life per square inch.

Researchers have long explored this sort of "lithium-air" battery, but IBM's demonstration shows it can actually be built. "The fundamental operation of the battery is no longer in question at all," says Winfried Wilcke, the senior manager of IBM's project. The company believes that with this technology, it can indeed produce a car battery that can take you 500 miles.

Wilcke adds, however, that the technology is still a long way from showing up in the marketplace. "A lot of other things have to be done before we can put this in a car," he says. But he believes this will happen some time after 2020.

As it stands, battery-powered cars are far from ubiquitous because current battery technology is too heavy. The ratio of weight to the amount of power provided means that you can't have battery that duplicates what you get from a tank of gas. Improvement to battery technology may give you move power, but this is often offset by added weight.

What Wilcke and his team have done is remove the oxygen from their batteries, relying instead on the oxygen in the surrounding air. Oxygen flows into the battery's "open system" cell, much as it moves into a combustion engine. Inside this cell, it slips into tiny spaces that measure about an angstrom (0.00000000001 meters), and it then reacts with lithium ions on the battery's cathode. That reaction turns the lithium ions to lithium peroxide, releasing electrons and generating electricity for the engine.

"You don't need to squeeze your reaction product into material," Wilcke says. The battery can produce up to 10,000 milliamp hours per gram of cathode material used.

Wilcke is quick to point out that this big increase won't translate to the same power increase once the technology reaches the market. There are still added materials to facilitate the reaction that offset parts of the power gains. But it does show how much more energy can be stored.

Once the battery is saturated with oxygen, it reaches the end of its charge, and it must be connected to a power source to recharge. When recharging, it releases oxygen back into the air, returning the lithium back to its ion state.

Wilcke's team, along with teams based in Zurich, Switzerland, built the battery with the help of IBM's Blue Gene supercomputer using "atomistic modeling" to determine how ions and molecules of the proposed battery would interact.

Wilcke's group will soon publish a paper on the technology, but until then, the company is giving few details about its design. But Wilcke did say that his group does not believe that graphene and carbon are good materials for lithium-air batteries. Carbon had been used because it's a cheap way to create surfaces, but, he says, it's not stable enough for long-term use.