Recharge A Battery in Seconds
Could it be possible to recharge batteries in seconds rather than hours? That's a definite "yes" according to MIT engineers after creating an electrical beltway.
Although hooking up a power adapter to a cell phone or iPod -and waiting for what seems like forever for the devices to recharge- is a part of everyday living, wouldn't it be just grand if those devices could recharge on the fly? Instead of thirty minutes or an hour, they'd power up in ten or fifteen seconds? Cutting down battery recharge time -while saving valuable consumer time- would change the lifestyle of every individual on the face of the planet, whether they're juicing up Sony's PlayStation Portable or keeping YouTube on the laptop from blacking out.
For a group of MIT engineers, that's exactly what they set out to do: re-engineer the surface of lithium iron phosphate to ultimately create an efficient, electrical beltway for lithium ions to use. Because state-of-the art rechargeable batteries have relatively low power rates despite their high energy densities, researchers once thought that lithium ions (and electrons) moved too slowly through the battery material. However, Gerbrand Ceder, the Richard P. Simmons Professor of Materials Science and Engineering, also head of the current project, said that the ions themselves should actually be moving very quickly according to computer calculations. Thus, he concluded that something else was causing the slowdown.
Further study showed that the lithium ions indeed moved extremely fast into the battery material, but only by way of surface tunnels if set directly in the path of the lithium ions; those that did not enter surface tunnels did not pass into the material. The new surface created by Ceder and Byoungwoo Kang, a graduate student, allows the lithium ions to move across the material as if on the beltway of a major city, getting off at the next exit -a surface tunnel- rather than halting altogether.
By utilizing this newly re-engineered material, Ceder and Kang created a small battery that could be fully recharged or discharged in 10 to 20 seconds- a fraction of the time it takes to recharge a battery cell made from the original, unprocessed material. As an additional benefit, the new material degrades far less than current rechargeable batteries when repeatedly charged and recharged. And because less material is needed for the same end result, consumers would benefit from a lighter, smaller battery.
"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 conclude. Apparently, the re-engineered material can also be applied to electric car batteries although they would be limited to the amount of power available on the consumer's electric grid.
Still, faster recharge times would make the world a better place. Unfortunately, the re-engineered rechargeable batteries won't see the light of day -or at least the hands of consumers- for another two or three years.