Fujitsu today announced its co-development with NTT DoCoMo of a prototype high-capacity micro fuel cell and the prototype development of an external recharger for FOMA handsets.

For the prototype micro fuel cell device, the concentration of the methanol fuel used was raised from 30%, the concentration used for the companies' previous fuel cells, to a remarkably higher concentration of over 99%. This enables the prototype device to charge up to three FOMA handset batteries with just 18 cc of methanol.

In comparison with conventional lithium ion batteries, micro fuel cells offer theoretical performance that is ten-fold, and are capable of high-density storage of energy at practical performance levels three times greater.

In addition, since micro fuel cells can use methanol derived from biomass resources, there is anticipation that they will help reduce burden on the environment.

Since micro fuel cells that employ methanol produce energy through the reaction between methanol and oxygen present in the air, power capacity can be increased by raising the concentration of the methanol solution.

However, for passive type fuel cells (a fuel cell in which no mechanical-operation parts such as pumps or fans are employed) that are suited for miniaturization and lighter weight, a phenomenon known as "methanol crossover" occurred, which is a fuel permeation that occurs between battery electrodes when high-concentration fuel is used directly with passive fuel cells, thereby resulting in lower generation efficiency.

Fujitsu developed new technology that makes it possible to use high-concentration methanol with concentration of over 99% for a passive micro fuel cell. By developing and employing a new material that reduces the methanol crossover effect by half compared to Fujitsu previous materials and to one-twentieth that of other commercially available materials, and by using the water by-product which appears during power generation to dilute the fuel, Fujitsu succeeded in effectively limiting the decline of power generation efficiency when using high-concentration fuel.

Fujitsu and DoCoMo employed the new technology to co-develop an operable FOMA handset charger prototype.

Using the newly developed technology, the cradle-type passive micro fuel cell achieved a world record high-power output average of approximately 1 watt with methanol fuel of over 99% concentration.