Temperate fuel batteries for the car

2001/04/19 Galarraga Aiestaran, Ana - Elhuyar Zientzia

• Ingurumena
• Energia berriztagarriak

Although more and more models of electric cars are being invented (for example, see "Necar 5, a car with fuel cell" 11/01/2001), it is taking longer than expected to be seen on the street. Now, Nature magazine has announced that a new fuel cell allows these cars to be cheap, reliable and relatively fast.

The fuel cell manufactured at the California Institute of Technology, in addition to being more efficient in obtaining electricity from hydrogen, carries out this process at an adequate temperature. In fact, the existing fuel cells work above or below the 600 °C. For the manufacture of the new battery several components of both types have been unified, obtaining a fuel cell that works at intermediate temperature.

The molten carbonate batteries work at an approximate temperature of 650ºC and those of solid oxide at 700-1000 °C. The latter are already used in small-scale energy installations and trucks, but both types are unstable at high temperatures.

The fuel cells of electrolytic polymer membrane, which can be humid, work at temperatures below 100ºC. Although they are used in some buses in Canada, they are inefficient.

To be economically useful, fuel cells must be cheap, efficient, light and long-lasting. However, those of polymeric electrolytic membrane, besides being ineffective, are not economical, since the electrodes must be platinum. In addition, some fuels can flow through the membrane, causing a short circuit and cutting the energy current.

On the other hand, in the fuel cells of solid oxides operating at high temperature, although the electrolyte is solid, when heated can be crossed by the oxide ions with negative electric charge.

The new fuel cell combines the idea of solid electrolyte with the conduction of hydrogen ion of the fuel cells of electrolytic polymer membrane. At temperatures of around 160 °C, this mechanism achieves greater efficiency than the previous one.

However, there is still much to do to be able to market it and, according to the article, if you want hydrogen to be used as fuel and be cheap, you will have to wait until 2010.