40-hour laptop batteries on the way

Nanotechnology promises 10-fold increase in charge capacity

In just a few years we're likely to see notebook computer batteries that last more than three working days on a single charge. That'll be good news for successors to the MacBook Air - Apple's new machine has an iPod-esque non-removable battery.

Researchers at Stanford University have developed a way of using silicon nanowires to boost battery life in Lithium-Ion batteries up to 40 hours, rather than the current three or four.

"It's not a small improvement," assistant professor Yi Cui at Stanford University's Materials Science and Engineering Department, who made the discovery, told ZDnet Australia. "It's a revolutionary development."

The new Lithium-Ion batteries use a larger amount of lithium - which holds the charge - thanks to a new type of anode utilising silicon nanowires instead of the standard graphite.

Highest charge capacity

Such wires have "the highest theoretical charge capacity," according to Ciu's paper, published in Nature Nanotechnology. As they soak up the lithium, the nanowires inflate to four times their normal size and are thus capable of sucking up more power per charge than before.

"We are working on scaling up, and evaluating the cost of our technology," Cui told ZDnet, adding that he expected the battery to be commercially available within "several years".

Rechargeable Lithium-Ion batteries are used in most portable electronic devices such as notebook computers, digital media players, digital cameras, camcorders and mobile phones.