A new ultrabattery?

TallDave · Post by **TallDave** » Thu Oct 15, 2009 8:01 pm

http://www.jpost.com/servlet/Satellite? ... 5547719698

A new kind of portable electrochemical battery that can produce thousands of hours of power - and soon replace the expensive regular or rechargeable batteries in hearing aids and sensors and eventually in cellphones, laptop computers and even electric cars - has been developed at Haifa's Technion-Israel Institute of Technology.

Prof. Yair Ein-Eli in his Technion lab, where he invented a battery that is potentially as eco-friendly as sand.
Photo: Technion
The unique battery is based on silicon as a fuel that reverts to its original sand. The battery can also be left on the shelf for years and inserted into a device to provide immediate power.

I'm mildly skeptical...

Diogenes · Post by **Diogenes** » Thu Oct 15, 2009 9:24 pm

Heh. The site is overloaded.

hanelyp · Post by **hanelyp** » Fri Oct 16, 2009 4:29 am

A silicon-air fuel cell certainly has energy potential to be plausible.

Art Carlson · Post by **Art Carlson** » Fri Oct 16, 2009 7:50 am

An amazing report. The only technical spec they give is "thousands of hours".

chrismb · Post by **chrismb** » Fri Oct 16, 2009 8:44 am

... and that it is a silicon-silicon oxide process. The electro-chemists amongst us should be able to do a quick calc to see what the max power density is for such a battery, and derive a current for the "1000's hrs of power". Answers would be acceptable in units of pA, please!.....

Betruger · Post by **Betruger** » Fri Oct 16, 2009 8:55 am

Do you guys not have access to the paper, or does that not detail what you're looking for either?

Skipjack · Post by **Skipjack** » Fri Oct 16, 2009 9:32 am

Yep, some more details would be really great. I would like to see KW/h per kilogram and KW per hour maximum output. To me that is what makes the most sense. Also how expensive will it be per KW/h.

Art Carlson · Post by **Art Carlson** » Fri Oct 16, 2009 9:49 am

Betruger wrote:Do you guys not have access to the paper, or does that not detail what you're looking for either?

The abstract is here as 20. Silicon–air batteries:

A new “metal”–air battery based on silicon–oxygen couple is described. Silicon–air battery employing EMI·2.3HF·F room temperature ionic liquid (RTIL) as an electrolyte and highly-doped silicon wafers as anodes (fuels) has an undetectable self-discharge rate and high tolerance to the environment (extreme moisture/dry conditions). Such a battery yields an effectively infinite shelf life with an average working voltage of 1–1.2 V. Silicon–air battery can support relatively high current densities (up to 0.3 mA/cm2) drawn from flat polished silicon wafers anodes. Such batteries may find immediate applications, as they can provide an internal, built-in autonomous and self sustained energy source.

I couldn't find the full text online.

Betruger · Post by **Betruger** » Fri Oct 16, 2009 12:41 pm

I'll send you a copy at the same address as last time.

krenshala · Post by **krenshala** » Sat Oct 17, 2009 1:35 am

The Article wrote:Ordinary portable batteries are composed of a positive electrode called a cathode and a negative one called an anode.

Um, isn't the cathode the negative terminal? Or should I ignore this because its too technical for mainstream media to get correct?

vankirkc · Post by **vankirkc** » Sat Oct 17, 2009 6:45 am

Art Carlson wrote:
Betruger wrote:Do you guys not have access to the paper, or does that not detail what you're looking for either?
The abstract is here as 20. Silicon–air batteries:
A new “metal”–air battery based on silicon–oxygen couple is described. Silicon–air battery employing EMI·2.3HF·F room temperature ionic liquid (RTIL) as an electrolyte and highly-doped silicon wafers as anodes (fuels) has an undetectable self-discharge rate and high tolerance to the environment (extreme moisture/dry conditions). Such a battery yields an effectively infinite shelf life with an average working voltage of 1–1.2 V. Silicon–air battery can support relatively high current densities (up to 0.3 mA/cm2) drawn from flat polished silicon wafers anodes. Such batteries may find immediate applications, as they can provide an internal, built-in autonomous and self sustained energy source.
I couldn't find the full text online.

Isn't 0.3 mA/cm2 rather wimpy? I quick google of Lithium Ion density suggests they average 10 mA/cm2.

Art Carlson · Post by **Art Carlson** » Sat Oct 17, 2009 9:16 am

krenshala wrote:
The Article wrote:Ordinary portable batteries are composed of a positive electrode called a cathode and a negative one called an anode.
Um, isn't the cathode the negative terminal? Or should I ignore this because its too technical for mainstream media to get correct?

http://en.wikipedia.org/wiki/Cathode[quote]A widespread misconception is that cathode polarity is always negative. ... Consequently, as can be seen from the following examples, in a device which consumes power the cathode is negative, and in a device which provides power the cathode is positive[/quote]I always have trouble with this too.

chrismb · Post by **chrismb** » Sat Oct 17, 2009 9:27 am

It stumped me when I first came across looking at some faulty batteries. The guys sent a diagram and I thought "eh!?!", but it made sense after thinking about it - the cathode is where the electrons come from....the andoe is what attracts the electrons.

krenshala · Post by **krenshala** » Sun Oct 18, 2009 12:35 am

Ah, that makes sense. I hadn't thought of it this way before.