[Shaun]

Originally Posted by Cobbydaler

The technology has been around for a while:


From a University of Rochester press release in 2005...

ZDnet says this about them.

Lastly, they're not very good batteries. Even the latest devices, which are very clever in the way they saturate a porous structure with the gas and thus usefully capture quite a large number of the energetic electrons, have an energy density of the order of twenty five watts per kilo. Lithium ion batteries, the sort you have in your laptop, manage 1.8 kilowatts per kilo. That's 72 times more bang per gram. Do you fancy carrying a battery 72 times heavier than the one you have at the moment, especially if it's hotter than a sixty watt light bulb?