Fuel Cell secrets

Dear budding ecologists !

This article will give you the key to understand how works the super cell of tomorrow.

Be attentive to the following picture, and everything will become clear :

principe fonctionnement pac

Lets start the explanation of the phenomena with the hydrogen. When hydrogen arrives at the anode (green part), it looses 2 electrons and get into proton H+ :

“H2 => 2H+ + 2 e-“.

The 2 electrons run throw an electric circuit, and supply then the machines we use.

At the end of the electric circuit, electrons come back to the cell on the cathode (red part), and react with the oxygen to produce O2- :

1/2O2 + 2- => O2-.

The ions of O2- go throw the electrolyte and react with the proton H+ previously formed at the anode. This reaction produces water :

“O2- + 2H+ => H2O”.

In reality, all of those reactions happen in the same time, leaded by the difference of chemical potential between hydrogen and oxygen. The global reaction is :

H2 + 1/2 O2 => H2O

In SOFC (Solid Oxide Fuel Cell), cells are made with ceramics materials, the conduction of ions O2- is possible only at high temperature 600-700°C. It’s why to produce electricity, you need to heat the cell at this temperature, but once the reaction is engaged, as the water formation is exothermic (produces heat), it’s no need to feed the cell any-more. As long as the cell is feed with hydrogen and oxygen, it will produce a continuous among of electricity.

Isn’t clever ?

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