Researchers at MIT have bridged the characteristics of standard power cells and capacitors with specially prepared carbon nanotubes that for the first time can now serve as a positive electrode.
The work was published this week in the journal Nature Nanotechnology and boasts an increase of up to 10 times more power than conventional lithium-ion batteries, according to at least one account of the research.
The prototype batteries possess the positive characteristics of both capacitors in their ability to deliver very short high bursts of energy and still have the energy content of state-of-the-art lithium-ion batteries, around 200 Watt hours per kilogram. This combination makes them attractive for Electric Vehicles (EV) technology that requires quick bursts of power for acceleration.The researchers, led by Yang Shao-Horn and Paula Hammond, were able to get the carbon nanotubes to work as the positive electrode by coating them with an oxygen containing chemical. They then dipped the base material into the solution containing the carbon nanotubes and then duplicated this repeatedly building up layers of the carbon nanotubes by alternately charging them with positive and negative organic compounds.
While it would seem that this would be something to pursue for commercial applications, it’s not clear whether the researchers are even entertaining the idea. One reason for the diffidence may be that Shao-Horn already has another project for building larger electrodes to be used in EV applications.
This research is not even the first time that MIT researchers have offered a tweak to lithium-ion batteries that allows them to perform like an ultracapacitor that allows them to discarge and fully charge in seconds instead of minutes.