If you considered fuel-cell batteries to be state-of-the-art, then perhaps a new breed of battery built by a live virus will make you think again.

MIT researchers led by Angela Belcher have adjusted two genes in a bacteriophage virus known as M13 to prompt it to build an iron phosphate shell that it then attaches to a carbon nanotube.

Three times the power

While it might not sound much like a triple-A, the result is actually a powerful electrode that releases its electrons faster than conventional lithium cells and can, therefore, be an even more-powerful battery.

Belcher explained: "We could run an iPod on it for about three times as long as current iPod batteries. If we really scale it, it [could] be used in a car."

The virus effectively builds the iron phosphate shell in the same way a shellfish creates the layers of its own casing. All M13 needs is a solution of water and the right ions.

Commercial plans

So far, the work is still on the nanoscale, so there's a lot to be done before anything like the car batteries Belcher talks of is possible, however the team is already at work on the next step.

Commercial production of a virus-built battery based on manganese and nickel is a definite possibility, we're told.