Prototype Fuel Cell Debuts

CHIBA, JAPAN -- NTT DoCoMo is showing at this week's Ceatec show here a prototype fuel cell that it's developing with a Japanese start-up for use as a cell-phone recharger.

The polymer electrolyte fuel cell (PEFC) uses hydrogen gas as a fuel to produce electricity and is a compact 1 inch square and 2.8 inches long, and weighs 1.5 ounces.

The fuel cell is under development by Aquafairy, a startup spun out of Japanese firm Nitto Denko to work on the technology. NTT DoCoMo recently acquired a 36.5 percent stake in the company for an undisclosed sum.

The fuel cell can deliver enough power to recharge a cell phone three times before requiring a hydrogen refill. It is among a growing field of alternative battery sources being developed, in search of longer battery life.

Different Approach

While it's still some way from being a commercial product, the fuel cell is completely different to what NTT DoCoMo showed at Ceatec 2005. A year ago the company was displaying a direct methanol fuel cell (DMFC) that was developed by Fujitsu Laboratories and built into a cradle, into which a cell phone could be placed for recharging.

DMFCs are based on a different chemistry from the PEFC on show this year. They typically work by mixing methanol with air and water to produce electrical power.

For companies like NTT DoCoMo a future goal remains a fuel cell small enough and safe enough to be built directly into a cell phone. But the technology isn't at that stage yet so the first commercial fuel cell devices will likely be recharges that replenish the Lithium Ion battery inside of the phone but offer the advantage of being able to do so anywhere--not just within a couple of yards of a wall socket.