New batteries to revolutionize mobiles?

[Senpuu]

http://news.bbc.co.uk/2/hi/technology/8297934.stm

"Researchers have demonstrated a penny-sized "nuclear battery" that produces energy from the decay of radioisotopes."

"Nuclear batteries are an attractive proposition for many applications because the isotopes that power them can provide a useful amount of current for phenomenally long times - up to hundreds of years or more."

"And although the whole idea hinges on the use of radioactive materials, the devices are safe under normal operating conditions. "

This all sounds too good to be true. There was no mention of application, feasibility of mass production, interested parties, or much of anything that would give a good indicator on just how massive this news could potentially turn out to be. There are plenty of reasons this may never go anywhere, but if this does hit the mobile world in a few years? Imagine never having to recharge your phone or laptop and the implications it would have on mobile design...

 

[bmcassagne]

This sounds to me like something that doesn't put out nearly enough power for a laptop, but still, it would be awesome to have unlimited mobile power. I guess it's just a matter of time though before we have something like this to power everything. I think for laptops we'll see fuel cells way before this. Squirt in a little kerosene and game on for another few hours.

 

[CurseTheSky]

If these go to mass production and aren't horribly cost-prohibitive, it could really revolutionize mobile electronics. I'd imagine they'd be no more dangerous than your average smoke detector, unless someone tried to disassemble one.

On that note, I wonder if they'd let you on a plane with one of these.

 

[alyarb]

Originally posted by: Senpuu

This all sounds too good to be true. There was no mention of application, feasibility of mass production, interested parties, or much of anything that would give a good indicator on just how massive this news could potentially turn out to be. There are plenty of reasons this may never go anywhere, but if this does hit the mobile world in a few years? Imagine never having to recharge your phone or laptop and the implications it would have on mobile design...

it is too good to be true. from slow decays like this, the only energy you get is heat, which is something laptops have very, very tight budgets for. you have to surround your heat source with a geometry ideal for creating a temperature differential across an insulative barrier with conductors going through that barrier to create a potential on the conductor. it works like a peltier, but backwards, and the conversion efficiencies are very low (about half that of solar power). these devices are only used in situations where you need power AND heat at the same time, such as weather stations in the arctic/antarctic, unmanned lighthouses, very far away spacecraft, and things like that. depending on the mass of your fuel and the isotope you're using, you can get a wide range of energies from this technique, but the heat output is comparatively immense to the power conversion. check out this chart to see what i mean. you'll see these devices require several hundred kilograms of fuel and are not going to work mobile devices.

http://en.wikipedia.org/wiki/R...ctric_generator#Models

another way to do it is to emit fast beta particles at a phosphor, which then emit photons, and have a photovoltaic right on top of that phosphor. not sure about the conversion efficiencies at laptop-size level, though. but the device in the bbc article looks like a simple photovoltaic to me.

this article isn't exactly news especially given how vague it is. the technology has been around, just not miniaturized, and we can't really say if the efficiency increases with a decrease in size. i suspect the "nuclear battery" mentioned in the article is some kind of radiogenic thermionic conversion. they mention capturing charged particles directly from the decay though. that's not going to happen because the emission just isn't fast enough. you need several amps at 12 volts to run a laptop, and that would be 6.242E18 electrons per amp per second that you will need from the device. this is the technique the article implies, however. they could be using an isotope that is not suitable for RTGs (which would be silly since the article is too good to be true), because i'm unfamiliar with it.

no matter what it is though, there is no recharging.

 

[LongTimePCUser]

Hmm. Let's think about that.

Take a radioactive battery.
Put it in a notebook computer.
Place computer on lap.
2" from family jewels.
.......
I think we have a marketing problem here.

 

[CurseTheSky]

Originally posted by: LongTimePCUser
Hmm. Let's think about that.

Take a radioactive battery.
Put it in a notebook computer.
Place computer on lap.
2" from family jewels.
.......
I think we have a marketing problem here.

Well, with some of the other ridiculous claims from various products available through several sources, they could turn that marketing the other way as well.

 

[bmcassagne]

it is too good to be true. from slow decays like this, the only energy you get is heat, which is something laptops have very, very tight budgets for. you have to surround your heat source with a geometry ideal for creating a temperature differential across an insulative barrier with conductors going through that barrier to create a potential on the conductor. it works like a peltier, but backwards, and the conversion efficiencies are very low (about half that of solar power). these devices are only used in situations where you need power AND heat at the same time, such as weather stations in the arctic/antarctic, unmanned lighthouses, very far away spacecraft, and things like that. depending on the mass of your fuel and the isotope you're using, you can get a wide range of energies from this technique, but the heat output is comparatively immense to the power conversion. check out this chart to see what i mean. you'll see these devices require several hundred kilograms of fuel and are not going to work mobile devices.

Did you even glance at the article? They are the size of a watch battery, so I seriously doubt they will be several hundred kilograms. Also I believe it said they will use a liquid medium to generate electricity from a chemical reaction, so it is not PRIMARILY a heat generator.

 

[alyarb]

i read it and numerous articles that were released prior to BBC's rehash.

there is no chemical reaction. it is a slow nuclear reaction, by the definition of radiogenic decay. the sample emits beta particles and the novel liquid semiconductor will capture them, and could be useful for MEMS and other sub-milliwatt devices. you will never generate a large enough current for laptops given the geometric limitations that laptops present, even with a large sample (it's tritium gas), the idea that a scaled-up version could be used for laptops is insinuated only in the OP and it's not feasible to actually run the device. you can't rely on just beta emission to get the energies a laptop requires because you need to either accelerate the particles under high pressure or they must be very, very numerous. destruction of the tritium fuel containment vessel could be a veritable dirty bomb and the health/weapon risks are innumerable.

the only thing you can do is have a regular lithium battery that, when disconnected from AC power, uses a betavoltaic battery to recharge it at a very slow rate. if this technique were incorporated with thermocouples on CPU and chipset heatsink surfaces, i can see how battery life could be extended by 30-50% when the device is on. a hypothetical betavoltaic trickle-charger small enough for laptops would take much longer than 24 hours to charge up a 5000 mah lithium battery all by itself, though. the emission is very low and the resulting current is very low, which is why only pacemakers and similar devices are suitable applications at this point in the technology's life.