U.S. researchers say they have discovered a way to recharge batteries in a matter of seconds rather than hours, a discovery that could lead to smaller and lighter batteries for cell phones and other electronic devices.
Scientists say lithium batteries can store a lot of energy, but they are slow to charge and discharge.
Researchers had thought that lithium ions and electrons that carry the energy in the batteries were moving sluggishly through the interior of the battery material, which is why they take a long time to recharge.
But about five years ago, researchers at the Massachusetts Institute of Technology calculated the lithium ions should actually move very quickly through a common battery material called lithium iron phosphate.
The problem they say, is that the ions are sometimes blocked on the surface of the material as they try to get into the openings of tiny tunnels they travel through. By creating a new surface structure, the researchers say they have fixed the problem.
The result is a battery that can be fully charged in about 20 to 30 seconds, compaired to traditional lithium batteries, according to co-inventor Gerd Ceder. "And at that point I think it becomes a bit of a lifestyle modifier. If you are talking about, say personal electronic devices, typically we charge these overnight because we do not want to sit around for an hour or two," he said.
Ceder says the trade off is that because the batteries discharge their energy quickly as well, they require more frequent recharging. But he says they do not degrade as much as regular lithium batteries with repeated charging.
MIT researchers are now working on a way to make rapid recharge batteries that hold their energy longer.
Ceder says it is up to battery makers to decide when to start producing them. "If they wanted to they could fairly quickly insert this into existing battery cells. The material has been licensed to a maker of materials, a large supplier to the battery industry. If they scale it up, then battery makers could start testing it in large cells and commercialize it," he said.
Ceder predicts the rapid recharge batteries could be available to consumers in two to three years to power a wide variety of products like cell phones.
At this point, Ceder says the technology could not be used to power hybrid cars because batteries for the vehicles require more charging capability than homeowners have.
A study describing the development of high-speed lithium batteries is published this week in the journal Nature.