Membrane-electrode structure for electrochemical cells

A membrane-electrode structure for use in an electrochemical cell which comprises an ion exchange membrane with a cathode layer, and a retardation layer between said membrane and said cathode layer, said retardation layer comprising a blend of about 5 to 80% by weight of inorganic solid particles with about 20 to 95% by weight of a thermoplastic ionic conductive polymer binder having a melting point of about 230.degree. F. to 540.degree. F., said inorganic solid particles comprising at least one of the borides, carbides, and nitrides of metals of Groups IIIB, IVA, IVB, VB, and VIB of the Periodic Table, said binder consisting of a copolymer of a monomer of the general formula:

• CF.sub.2 .dbd.CZZ' (I)
• wherein Z and Z' are independently selected from the group consisting of --H, --Cl, --F, or --CF.sub.3, and
• at least one monomer selected from compounds represented by the general formula:
• Y--(CF.sub.2).sub.a --(CFR.sub.f).sub.b --(CFR.sub.f).sub.c --O--[CF(CF.sub.2 X)--CF.sub.2 --O].sub.n --CF.dbd.CF.sub.2(II)
• wherein Y is --SO.sub.2 Z
• Z is --I, --Br, --Cl, --F, --OR or --NR.sub.1 R.sub.2 ;
• wherein R is a branched or linear alkyl radical having from 1 to about 10 carbon atoms or an aryl radical;
• R.sub.1 and R.sub.2 are independently selected from the group consisting of --H, a branched or linear alkyl radical having from 1 to about 10 carbon atoms or an aryl radical;
• wherein:
• a is 0-6;
• b is 0-7;
• c is 0 or 1;
• provided a+b+c is not equal to 0;
• X is --Cl, --Br, --F, or mixtures thereof when n>1;
• n is 0 to 6;
• and R.sub.f and R.sub.f are independently selected from the group consisting of --F, --Cl, perfluoroalkyl radicals having from 1 to about 10 carbon atoms and fluorochloroalkyl radicals having from 1 to about 10 carbon atoms.