Friday, October 2, 2009

A nuke-powered cellphone or laptop?

One thing is a given: that all our modern electronic devices require electrical energy to function.

While many of our computers and other hi-tech appliances are happy to hook up to the mains, almost everything (even that desktop PC) we use these days has a battery of some kind in it.

Way back in the dim dark days of electronics, portable devices were powered by stacks of small zinc-carbon cells. Even before the arrival of the transistor, portable electronic equipment would run (albeit not for long) on these simple batteries.

With the arrival of solid-state technology, the battery requirements of portable devices was significantly reduced. No longer was it necessary to have two batteries (one for the filaments and another for the hi-tension supply). A single 9V battery or assortment of AA, C or D-sized cells would suffice.

However, the chemistry inside these batteries was still predominantly zinc/carbon and they were primary cells (not rechargeable). The single largest cost of ownership with these old devices was the price of regular battery replacement.

Tired of the endless expense of primary cells, new forms of secondary (rechargeable) cells began to appear, the main one using a nickel-cadmium chemistry. Although cadmium is a toxic and environmentally harmful material, this was in an era long before such things were an issue so NiCads (as they became known) proliferated and took portable devices to a new level of convenience and cost-effectiveness.

Since then we've seen numerous advances in electronics and battery technologies until now we have very low-drain, large-scale, low-voltage, low-power CMOS integrated circuitry that consumes comparatively miniscule amounts of electricity compared to earlier gear.

The state of the art in battery technology is now based on lithium chemistry. Lithium-Ion, Lithium-polymer and Lithium-iron-phosphate cells are not only far less environmentally unfriendly but also offer much higher energy densities.

But where to from here?

While there has been much research in the area of supercapacitors which use nano-technology to store electrical energy as a surplus and deficit of electrons rather than through a chemical reaction, researchers confirm that this is still technology in its infancy.

Fuel cells have been promised for decades but, despite regular announcements, even from companies as highly respected as Toshiba, we still don't have those promised Vodka-powered laptops yet. Despite working well in the lab, there are clearly a raft of issues associated with large-scale manufacture of such fuel cells so don't hold your breath.

One idea that has been mooted in some circles recently is the nuclear battery.

Yes, that's right -- a small capsule of radioactive material that can generate electricity with no moving parts.

While this might sound like a giant step backwards and a potential source of hideous environmental danger, that might not be the case.

Thanks to the much lower power demands of many modern portable electronic devices, the amount of radioactive material required may be quite small-- little more than was once used regularly to create the luminous dials on clocks and wrist-watches back in the 1950s.

It's also worth nothing that more than a few of the unmanned spacecraft we've sent on missions far from earth have had nuclear batteries onboard. They're not a new concept but one that may see a revival if research is able to significantly reduce the amount of nuclear material required.

Or perhaps the nuclear battery will be a solution looking for a problem.

What manufacturer would want to try and sell a battery that lasts for decades rather than weeks? Unless you charge a fortune you'd soon saturate the market and sales would dry up.

And then there's the issue of fashion and the relentless advance of electronics technology.

Take the humble cellphone to see what I mean...

These days, people decommission or throw away perfectly good, fully functional mobile phones at regular intervals -- simply because a better, smaller, more powerful replacement comes on the market. What is the point in supplying a battery that lasts 10 years without a recharge when the item it is designed to power might have an effective life of just a year or so?

Nuclear batteries will re-appear but it's unlikely we'll see them in consumer electronics -- they just don't make commercial sense.

Likewise, you won't see cars powered by nuclear batteries -- that really would require too much radioactive material and definitely would pose an environmental/safety problem.

However, I would not dismiss the chance that nuke-powered watches and clocks may appear in the not too distant future -- no backlight required :-)

And let's be honest, wouldn't it be marvelous if you never had to worry about your cellphone or laptop battery going flat again?

1 comment:

  1. Remember, you read about it right here on Entropy first -- but now other sites are picking up on the news:

    PopSci story