Researchers charge towards nanotube batteries

BATTERIES FITTED with nanotube electrodes are set to offer sizeable gains in power and capacity.

A team of researchers from Massachusetts Institute of Technology (MIT) propose replacement of the electrodes in batteries with ones that are made from carbon nanotubes. The aim is to increase the electrode surface area, which in turn improves the energy capacity and power density of the batteries.

While the overall goal might sound simple, the devil is in the details. Making carbon nanotubes requires use of a binding agent, which actually brings down the conductivity of the electrode, countering any gains in performance.

The researchers developed a method of creating ultra-dense electrodes, which demonstrated an ability to hold and release charge, something that the team has now applied to lithium-Ion (Li-Ion) batteries. As the lithium reacts with the electrodes, the carbon nanotubes afford the electrodes a step change in the increase in surface area for the lithium ions to react with.

All that's left is for the MIT researchers to speed up the production of the carbon nanotubes. The team has already reduced manufacturing time from a week to just hours, but the process still needs maturing before it can become commercially viable.

It's not surprising that researchers are trying to find a ways to manufacture carbon nonotubes cheaply. The technology could be used to write batteries directly onto circuit boards, heralding the potential for producing even smaller and more powerful batteries. µ