backtop


Print 31 comment(s) - last by alan328.. on Dec 23 at 9:20 AM


Silicon Nanowires Before and After Absorbing Lithium  (Source: Stanford News Service)
New lithium-ion battery using silicon nanowires will store ten times the energy of current lithium-ion batteries

Many electronic devices -- from notebooks to cell phones -- rely on batteries for operation. Rechargeable batteries account for much of the weight in today’s electronic devices so the size of the battery has to be tempered with battery life to get an ideal product.

Stanford assistant professor of materials science and engineering Yi Cui, graduate student Candace Chan and five other researchers made a breakthrough for lithium-ion batteries. The researchers used silicon nanowires in the battery anodes to design new lithium-ion batteries that can hold ten times the electrical charge of current batteries of the same size.

Cui told the Stanford News Service, “It's not a small improvement. It's a revolutionary development.” Cui and his team were able to get the greatly increased electrical storage capacity by growing silicon nanowires on a stainless steel substrate, which provides excellent electrical conduction.

Researchers say that the amount of energy a currently lithium-ion battery can store is dependent on the amount of lithium it can store in its anode typically made from carbon. Silicon has a higher storage capacity than carbon. The use of silicon in lithium-ion batteries had been attempted before but the growing and shrinking process caused by adding and removing lithium caused the silicon to break down severely degrading the performance of the battery.

Chan says, “The people kind of gave up on it [silicon] because the capacity wasn't high enough and the cycle life wasn't good enough. And it was just because of the shape they were using. It was just too big, and they couldn't undergo the volume changes.”

The silicon nanowires used in the researcher’s batteries are tiny at about one-thousandth of the thickness of a sheet of paper and are able to inflate to four times their normal size as they take in lithium without breaking during the duty cycle of the battery. The researchers say that the infrastructure behind silicon is mature meaning the new technology could be pushed to market quickly.

Cui has filed a patent application and is considering starting a company to product batteries based on the technology or collaborating with an established battery maker. This development could also mean much smaller and lighter batteries than we have today that store as much electricity, which would be a huge boon for mobile electronics.

Cui sees the new and improved lithium-ion batteries as being particularly interesting to electric vehicle makers such as GM with its Chevy Volt due in 2010.



Comments     Threshold


This article is over a month old, voting and posting comments is disabled

RE: Recycycle
By mcnabney on 12/20/2007 11:43:43 AM , Rating: 2
You are right! I never thought of lawn mowers as being a target for this. Those nasty inefficient 2 stroke engines pollute more in one mowing than my two cars do in a week. Except for the commercial ones that are used all the time, most mowers aren't used for more than 2 hours at a time.

And they can't replace the current crop of batteries we use. Li-Ion voltage is too high. 3.6V per cell I believe, which is more than double the 1.5V standard. NiMH run at 1.2 and I have never known why that isn't more of a problem.


RE: Recycycle
By TomZ on 12/20/2007 12:22:13 PM , Rating: 1
Lawn mower engines are 4-stroke, not 2-stroke, at least in the US.


RE: Recycycle
By fic2 on 12/20/2007 1:39:24 PM , Rating: 2
Yes, they are 4-stroke, but they have little, if any pollution controls on them.


RE: Recycycle
By TomZ on 12/20/2007 9:14:28 PM , Rating: 1
Agreed, but they're not burning tons of oil like 2-strokes.


RE: Recycycle
By AlexandertheBlue on 12/20/2007 9:41:43 PM , Rating: 2
Not necessarily. You are assuming that all lawn mowers are new. Many old lawn mowers, especially lawn boys, are 2 stroke.

However that said, I have always preferred gas mowers over electric as they have had more power and are thus able to cut longer grass more easily. With the new battery density hopefully thay are able to remedy this and give decent operating time and recharge time.


"We basically took a look at this situation and said, this is bullshit." -- Newegg Chief Legal Officer Lee Cheng's take on patent troll Soverain

Related Articles
GM Readies Chevrolet Volt for 2010
November 21, 2007, 3:00 PM













botimage
Copyright 2014 DailyTech LLC. - RSS Feed | Advertise | About Us | Ethics | FAQ | Terms, Conditions & Privacy Information | Kristopher Kubicki