Lithium-ion batteries are fast becoming the battery of choice for plug-in hybrid and electric vehicles. But they're far from perfect: they don't keep a charge for long (the Nissan Leaf's battery will require a recharge every 100 miles), and they degrade over time.
Enter Contour Energy Systems, a self-described portable power company that this week acquired carbon nanotube li-ion battery technology from MIT. According to Contour, the technology allows li-ion batteries to produce up to a tenfold increase in power--effectively eliminating all concerns about range anxiety.
Contour explains the technology:
Carbon nanotubes--sheets of pure carbon atoms rolled up into tiny tubes--"self assemble" into a tightly bound structure that is porous at the nanometer scale (billionths of a meter). "These carbon nanotubes contain numerous functional groups on their surfaces that can store a large number of lithium ions per unit mass,” says Professor Shao-Horn of Mechanical Engineering and Materials Science and Engineering at MIT.
As a result, Contour's batteries can produce high power outputs in short bursts as well as low power outputs over longer periods of time. The batteries can deliver 10 times more energy than traditional li-ion batteries, and they don't degrade over time--after 1,000 charge cycles, Contour found no discernible change in performance.
The battery technology won't be found in the upcoming generation of EV's, however. Carbon nanotubes aren't yet produced in large enough quantities for mass production of nanotube-containing li-ion batteries. But that may change once Contour is ready to commercialize its battery -- and once enough of us start needing a charge every 100 miles.