Thanks to this action, even small fuel cells can provide more than 4,000 hours of service life, opening the door to their practical application as small, portable power sources.

Using the new cathode material, Hitachi Maxell plans to develop a portable power source that can be used in outdoor settings and in emergencies.
 
It hopes to have ready by 2010 commercial versions that use hydrogen derived from aluminum and water as the fuel and can provide 10-100 watts of power.

In a solid-polymer fuel cell, hydrogen ions generated at the cathode migrate through the electrolyte to the anode, where they react with oxygen ions to form water. Platinum is attached to the carbon electrode to catalyze the generation of oxygen ions. Because the fuel cell is constantly being started and stopped, the bonds between the carbon and platinum break over time and the platinum becomes free to dissolve and move into the electrolyte, where it accumulates as an impurity, hampering hydrogen ion migration and reducing the power output.

For the large fuel cells designed for cars and homes, a special device can be attached to the fuel cell to separate and remove the dissolved platinum. But this is not an option for small, portable fuel cells.

Hitachi Maxell solved the problem by developing a cathode material that uses an organic compound as an additive. The oxygen from this organic compound interacts with the dissolved platinum and keeps it inside the electrode, preventing the migration to the electrolyte that degrades fuel cell performance.

In tests, fuel cells with the new cathode retained 90 per cent of their original power output after 5,000 on-off cycles, whereas the performance of conventional fuel cells fell more than 50 per cent.