Patent ID: 6902849

Claim:
An electrochemical cell which comprises a first plate, a second plate placed at a distance from the first plate, and at least one membrane-electrode assembly fitted between the first and the second plates, the assembly comprising a first porous electrode, a second porous electrode placed at a distance from the first electrode, a membrane fitted between the first and the second electrode, first feeding units for feeding fuel to the first electrode, second feeding units for feeding an oxidant to the second electrode, and electric switching elements which enable electric switching between the first and the second electrode, characterized in that the membrane material of the membrane is a non-aromatic polymer film which comprises sulfonic acid groups linked directly to the linear carbon backbone of the polymer chain of the polymer in such a manner that the total concentration of sulfonic acid groups in the membrane is 0.4-3 meq/g and they are homogeneously distributed in the membrane material so that their concentration in the middle of the membrane is at minimum 0.2 meq/g.