MIT Chips Away at Lithium Ion Barrier

Via CNET -

Engineers at MIT have made a breakthrough that could translate into smaller, lighter, and faster-charging lithium ion batteries, the Massachusetts Institute of Technology announced Wednesday.

Gerbrand Ceder, the Richard P. Simmons Professor of Materials Science and Engineering at MIT; aided by Byoungwoo Kang, a graduate student in materials science and engineering, have made a small battery that can be fully charged or discharged in 10-20 seconds.

A detailed explanation on how they did this has been published in the March 12 issue of Nature, but here is a brief recap of what they essentially accomplished.

While lithium ion batteries have high energy densities, they are also known for their inability to gain and discharge energy quickly. That is why it commonly takes hours to recharge the battery on a plug-in electric vehicle.

Electric vehicle proponents have been struggling with this battery issue, some coming up with clever ways around it. Better Place, for example, came up with the idea of drivers saving time by swapping-out discharged car batteries for fully charged ones at electric vehicle stations.

Ceder and Kang experimented with the way lithium ions move in and around lithium iron phosphate, a material commonly used in lithium ion batteries. They worked with it to develop a new surface structure that gets ions to move more quickly from one place to another. They compare their project to building a beltway that goes around a city to avoid traffic, but has tunnels that let you drop in to exactly where you need to be.

"The ability to charge and discharge batteries in a matter of seconds rather than hours may open up new technological applications and induce lifestyle changes," according to Ceder and Kang's paper in "Nature."

In addition to being significantly faster, batteries made with their material degraded much less than usual lithium ion batteries after repeated discharges and recharges during testing. Because of that, they believe their batteries could be made with less material making them lighter and smaller.

Because their invention is not a completely new material, but a change to the way it's structured, the researchers said in a statement that their material could be implemented into commercial batteries within 2-3 years.