(Link to Science Friday interview added, below.) An MIT group led by Gerbrand Ceder says it knows how to build a battery that be could recharged in seconds instead of hours. Their battery would also be capable of rapid discharge, and act much like a capacitor. Their work is reported in Nature and the MIT website. Ceder and colleagues, reviewing data and calculations related to lithium iron phosphate, believed that lithium ions should moving much faster than was being observed in battery applications. They sought to figure out what was putting on the brakes in the system.
The group realized that it was a matter of where the lithium ion is positioned. If it’s in front of a tunnel entrance, it rapidly enters the tunnel, but if out of position in relation to the tunnel, it cannot move to access that entrance. To solve this problem, Ceder and his group developed a new surface structure that does allow the lithium ions to move quickly around the outside of the material until it reaches a tunnel. Prototypes have been built that charged or discharged in only 5% (or less) of the time it takes for a cell made from the unprocessed material. Ceder says another benefit of his group’s material is that it resists degradation due to charged-recharged cycles, and therefore would require less material for the same performance. This could mean smaller or lighter batteries. The group thinks seconds-long charge-discharge could be a game-changer in applications ranging from cell phones to electric cars. The technology has been licensed by two companies and products could be in the marketplace, according to Ceder, in a few years. [Update] Ceder’s is interviewed Ira Flatow for NPR’s Science Friday is available here.