Batteries that recharge in seconds

Researchers at MIT have discovered a way to tweak batteries that allows them to recharge in seconds rather than hours.

This breakthrough in lithium-ion batteries, which are popular in cellphones and laptops, could radically change the way people interact with devices – possibly fulfilling both a gadget-lover's dream and an environmentalist's nightmare.

The problem with current lithium-ion technology is that the energy flows into and out of batteries rather slowly. To figure out why, professor Gerbrand Ceder developed computer models of how the ions and electronics cruise through the battery. His team found that the ions actually zip at incredible speeds, but they take really slow routes.

"Lithium ions can indeed move very quickly into [lithium iron phosphate, one of the main battery materials] but only through tunnels accessed from the surface," says the MIT announcement. "If a lithium ion at the surface is directly in front of a tunnel entrance, there's no problem: it proceeds efficiently into the tunnel." But if it's not line up perfectly, the ions need to navigate through a labyrinth of nanoscale twisty streets, looking for the nearest tunnel.

Ceder and Byoungwoo Kang, a graduate student in materials science and engineering, devised a way around the problem by creating a new surface structure that does allow the lithium ions to move quickly around the outside of the material, much like a beltway around a city. When an ion traveling along this beltway reaches a tunnel, it is instantly diverted into it.

To test out their new traffic flow, the two designed a small battery that would normally take six minutes to charge. The prototype fully charged and discharged in 10 to 20 seconds.

This significant reduction "may open up new technological applications and induce lifestyle changes," Ceder and Kang write in their upcoming article in the journal Nature.

Many people wouldn't think twice about recharging their cellphone midday. More devices could offer power-hungry features, such as video, because regaining the lost energy would no longer be a chore. Also, gadgets could potentially pack in new features that weren't practical before because they couldn't suck out energy fast enough.

Then again, this discovery also raises troubling questions about energy use in general. Users may no longer mind recharging a gizmo three times throughout the day, but they are also using three times more energy than before.

Update: Commenters have made a good point that this original article was thinking too small. Rapid-release energy for devices could be fun, but fast-charging lithium-ion batteries for cars could revolutionize electric vehicles. While current electric cars need to be plugged in overnight, these new MIT batteries could make filling up as easy as stopping for gas.

As Daron writes: "36 times faster to recharge than a standard lithium battery. For the Tesla roadster this means it could take 6 minutes instead of 3.5 hours to recharge a battery that lasts 220 miles."

Read through his and the other comments for more interesting ideas. Thanks, readers.