"Spin Battery" Effect Discovered

An anonymous reader writes "Researchers at the University of Miami and at the Universities of Tokyo and Tohoku, in Japan, have discovered a spin battery effect: the ability to store energy into the magnetic spin of a material and to later extract that energy as electricity, without a chemical reaction. The researchers have built an actual device to demonstrate the effect that has a diameter about that of a human hair. This is a potentially game-changing discovery that could affect battery and other technologies. Quoting: Although the actual device... cannot even light up an LED..., the energy that might be stored in this way could potentially run a car for miles. The possibilities are endless, Barnes said.'"

Can't light an LED

[Taibhsear]

Is this due to the scale of the device/experiment or is it a limitation in the output that they can get it to generate so far?

Re:Can't light an LED

[Anonymous Coward]

Well the device they've built has the diameter of a human hair it doesn't really matter (unless it's also really really long). Ten thousand in a battery the size of a AA would surely give off more energy than existing alkali or NiMH batteries of the same size.

Isn't there already energy in the spin

[Anonymous Coward]

Can't we just extract it without having to put some in first?

Re:Can't light an LED

[BillOfThePecosKind]

I would think it would be a limitation of the test size. If it's like any other electrical device, we should be able to stack a WHOLE bunch of them in series to create larger voltages. I really hope this goes somewhere, a lot of what is holding us back from implementing more renewable energy sources is the fact that we have no efficient (cost efficient mostly) way of storing the energy.

I was hoping it was a spin isomer battery

[rford]

I though someone had got the induced decay of Hf spin isomers to work.

http://en.wikipedia.org/wiki/Induced_gamma_emission [wikipedia.org]

1300 megajoules per gram would be a good battery.

Re:Can't light an LED

[poetmatt]

Well, it's potentially far more efficient than other current methods but how far is to be determined. Magnetic charges do not tend to hold forever, and are limited by certain mechanical aspects that can make it more difficult to harness long term too.

However, both of those are just small engineering issues and should be things that can be resolved through working out the magnetics.

Re:Can't light an LED

[Chyeld]

More importantly, you can stack several chemical batteries together for more power and the only issue you have to worry about is heat.

Stack several magnetic based batteries together, are you going to have to worry about their fields interfering with each other? What if this is only a workable model when the battery IS the width of a human hair.

Re:Achem

[davolfman]

Mu metal?

Static magnetic field?

[Wilson_6500]

Spintronics is a little too far out of my ken (I was always more of a radiation physicist, where everything comes in nice little packages instead of fields), but if I'm reading the paper correctly, they're saying that they can apply a static magnetic field to one of these devices and then can measure a voltage drop across a resistor hooked up to the device. They can get a few millivolts from a 1.2 Tesla field, which persists for at least ten minutes but does decay in that time frame. When they remove the magnetic field, the voltage disappears.

I guess my question is that if the field is static, where is the energy coming from that drives the current giving rise to the voltage? I'm also wondering how one regenerates the voltage after it discharges completely.

EMP

[mrops]

Article describes that nano-magnets apply a large magnetic field to "wound-up" the spin-battery.

Having charged the hypothetical battery the article claims, the one that can run a car for miles. It is possible to discharge this battery near instantaneously, that should theoretically generate an EMP without a nuke. Something the military would be interested in.

Off to patent my idea now.

Re:Can't light an LED

[BillOfThePecosKind]

Hmmm, that is a very good point. Assuming those objects have a hysteresis curve like any non-permanent magnet you would have to be careful about how you put them together. Maybe there is a way they can "wind" the strands around a core to negate any potential field problems, kind of like how interleaving windings on an inductor can help with copper loss. All things considered, sounds like a fun experiment!

Re:Miles? Car Batteries? You might want to check:

[davidsyes]

(search on keyword "battery" if you don't want to read all the way through)

http://www.theatlantic.com/doc/200904/chinese-innovation/3 [theatlantic.com]

Some here may already have read about this, but it appears that China makes some very good batteries, mainly for the electronics industry. Now, it seems they had not long ago seen a company produce (ugly) electric cars, but batteries that rival the USA Big 3 (well, which of them's big anymore?) and even Tesla. Given that Tesla's demo/sports car ran over $100k, and despite their announced sedan:

http://www.autoblog.com/2008/02/17/tesla-whitestar-electric-sedan-to-debut-this-year/ [autoblog.com]

there is going to be some stiff global competition for such batteries, especially if what Chinese companies are working on can take off.

To recap the recent Detroit Show:

http://www.theatlantic.com/doc/200901u/detroit-auto-show [theatlantic.com]

Re:Achem

[Anonymous Coward]

Magnetic spin != magnetic strength. This is like... storing energy in a photon's polarization, instead of as the photon itself.