Assemblies for electrochemical devices

摘要

MEA 7-layer assemblies with gasket, comprising:
a film of ionomeric membrane (3), containing functional acid groups —SO3H and/or —COOH, having in at least one direction, called direction x, a size variation lower than 0.08%;two GDL sheets (1) and (2) in porous material having on one surface an electrocatalytic layer, not shown in the Figures, of which:
the first sheet DGL (1) is coextensive with the membrane (3) surface, positioned so as to overlap thereto;the second sheet GDL (2), having a lower width but the same length of the film of membrane (3), measured in the x direction;the two sheets (1) and (2) placed so that the electrocatalytic layer comes into contact, respectively, with each of the two membrane faces;a gasket positioned according to a frame shape along the assembly perimeter.

主权项

1. A 7-layer membrane electrode assembly with gasket, comprising:
a film of ionomeric membrane having in the direction x, a size variation lower than 8%, determined by the following expression:
(A−B)×100/B wherein:
B is the membrane length in the x direction, after drying under vacuum for a time of 1 h at 105° C. and at a residual pressure lower than 30 mBar;A is the membrane length in the x direction after treatment in distilled water at 100° C. for 30 minutes; first and second gas diffusion layers in porous material each having on one surface an electrocatalytic layer, of which:
said first gas diffusion layer is coextensive with the ionomeric membrane surface;said second gas diffusion layer has a gas diffusion layer length equal to that of the film of ionomeric membrane, measured in the x direction, and a shorter width than the film of ionomeric membrane, leaving uncovered two strips of the film of ionomeric membrane parallel to the x direction;said first and second gas diffusion layers are placed so that the electrocatalytic layer contacts, respectively, each of the two membrane surfaces, a gasket placed according to a frame shape along the assembly perimeter, so as to penetrate along the perimeter of said first and second gas diffusion layers for at least 1 mm, and which covers the two uncovered strips of film of ionomeric membrane parallel to the x direction.