Recharge batteries in just seconds
Scientists at the Massachusetts Institute of Technology (MIT) have developed a technique that allows lithium batteries to be charged and discharged in a matter of seconds rather than hours.
The discovery is bound to make recharging mobile phones and other devices much more convenient. It can also find its applications in the electric car industry, making vehicles more powerful.
The technique is based on the study of material called lithium iron phosphate (LiFePO4), commonly used to make electrodes in rechargeable batteries. About five years ago Gerbrand Ceder – a Professor of Materials Science and Engineering – and colleagues made computer models that showed that the material would allow for lithium ions to travel through it very fast. Theoretically this would ensure quick charge and discharge rates, but for some reason it didn’t work.
Further study revealed the problem was not with the material itself but with the way lithium ions enter it. Ions travel through crystal via tunnels, but to get on its way an ion must be near an entrance. If there’s none available, the ion creeps around the surface until it finds one. This is what limits ion current in the battery and does not allow it to charge and discharge fast.
Ceder and his co-author Byoungwoo Kang, a graduate student, have found a way to forge the surface so that ions can travel quickly over it, like cars travel on a beltway around a city. The technique also lowers the rate at which electrode material degrades over time.
The researchers have produced a small battery that can be fully charged in 10 to 20 seconds. A normal battery this size and capacity would take six minutes to do so.
“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,” Ceder and Kang said in their paper published Thursday in Nature magazine.
Ceder estimates the technology may hit the market as soon as in two or three years, thanks to the fact that it changes little in the manufacturing process.
