“I don’t think it is feasible to put a fuel cell into a phone,” chief technology officer Michael Priestnall told Electronics Weekly. “Today, lithium [battery] technology will give adequate run time.”

Priestnall estimates the power threshold above which fuel cells will be applicable is around 5W. “We are aiming for 10W at the bottom end,” he said.
 
CMR, a spin-out from the Generics Group, has developed porous materials that allow fuel and air to flow all the way through a stack of fuel cell elements rather than requiring bulky manifolds between elements to get fuel in and waste out.

“We believe with optimisation we will have getting on for 1kW/l power density and in the long term 10kW/l, that is 50W from 3cm³,” said Priestnall.

These figures are just for the stack, which converts methanol and air into electrons and water.

Each fuel cell also needs air and fuel pumps, and a fuel/waste tank.

In system terms, Priestnall estimates pumps stack and tank together will hit 800Wh/l by the end of 2007, which equates to 1kWh/kg. “In the long term we are talking of integrated systems with up to 2,000Wh/kg.”

CMR is aiming its technology at laptops, portable power generators and vehicles.