Current collector bonded to a solid polymer membrane

Claim 1

A method of forming an assembly of an ion permeable menmbrane, electrode, and current collectors, comprising the steps of: (a) forming a foundation layer of a porous, electrically conductive material; (b) at least partially coating a fluoro­polymer binder on at least one surface of the foundation layer; (c) applying a particulate catalyst material over the fluoropolymer binder on the foundation layer; (d) dispersing a polymeric material as a solution or dispersion over the catalyst material in a manner to obtain penetration of the polymeric material into the porous foundation layer to form a substantially continuous coating on the catalyst material and the at least partially coated foundation layer; and (e) applying heat and/or pressure to the assembly to enhance the flow of the polymeric material into the foundation layer and around the catalyst material to obtain adherence of the catalyst material to the foundation layer and to sinter the polymeric material into a substantially non-porous layer around the catalyst material.

Claim 2

A method of forming an assembly of an ion permeable menmbrane, electrode, and current collectors, comprising the steps of: (a) forming a foundation layer of a porous, electrically conductive material; (b) at least partially coating a fluoro­polymer binder on at least one surface of the foundation layer; (c) applying a particulate catalyst material over the fluoropolymer binder on the foundation layer; (d) dispersing a polymeric material as a solution or dispersion over the catalyst material in a manner to obtain penetration of the polymeric material into the porous foundation layer to form a substantially continuous coating on the catalyst material and the at least partially coated foundation layer; and (e) applying heat and/or pressure to the assembly to enhance the flow of the polymeric material into the foundation layer and around the catalyst material to obtain adherence of the catalyst material to the foundation layer and to sinter the polymeric material into a substantially non-porous layer around the catalyst material.

Claim 6

The method of any one of the preceding claims including the step of making two similar sized assemblies, placing the two assemblies together such that the non-porous polymeric surfaces are in intimate contact with each other, and applying heat and/or pressure to form a single planar assembly containing two current collectors and having a non-porous, ionically conductive polymer layer therebetween.

Claim 7

The method of any one of the preceding claims, wherein said fluoropolymer binder for the foundation layer is a thermoplastic, non-ionic precursor of a solfonic acid copolymer having an equivalent weight range of from 500 to 2000.

Claim 8

The method of any one Claims 1 to 5, wherein said fluoropolymer binder for the foundation layer is a thermoplastic, non-ionic precursor of a carboxylic acid copolymer.

Claim 11

The method of any one of the preceding claims, wherein the binder is a copolymer formed from the polymerization of one or more monomers selected from the group of monomers represented by the general formula: CF₂=CZZ′      (I) where: Z and Z′ are independently selected from -H, -Cl, -F, or -CF₃. with one or more monomers selected from a second group of monomers represented by the general formula: Y-(CF₂) a -(CFR f ) b -(CFR f′ ) c -O-[CF(CF₂X)-CF₂-O] n -CF=CF₂      (II) where: Y is selected from -SO₂Z, -CN, -COZ, and -C(R³f)(R⁴f)OH; Z is selected from -I, -Br, -Cl, -F, -OR and -NR₁R₂; R is selected from a branched or linear alkyl radical having from 1 to 10 carbon atoms or an aryl radical; R³f and R⁴f are independently selected from perfluoroalkyl radicals having from 1 to 10 carbon atoms; R₁ and R₂ are independently selected from -H, a branched or linear alkyl radical having from 1 to 10 carbon atoms, and an aryl radical; a is 0-6; b is 0-6; c is 0 or 1; provided a+b+c is not equal to 0; X is selected from -Cl, -Br, -F, and mixtures thereof when n>1; n is 0 to 6; and R f and R f′ are independently selected from -F, -Cl, perfluoroalkyl radicals having from 1 to 10 carbon atoms, and fluorochloroalkyl radicals having from 1 to 10 carbon atoms, and optionally, one or more momomers selected from a third monomer represented by the general formula: Y′-(CF₂) a′ -(CFR f ) b′ -(CFR′ f ) c -O-[CF(CF₂X′)-CF₂-O] n′ -CF=CF₂      (III) where: Y′ is selected from -F, -Cl, or -Br; a′ and b′ are independently 0-3; c′ is 0 or 1; provided a′+b′+c′ is not equal to 0; n′ is 0-6; R f and R′ f are independently selected from -Br, -Cl, -F, perfluoroalkyl radicals having from 1 to 10 carbon atoms, and chloroperfluoroalkyl radicals having from 1 to 10 carbon atoms; and X′ is selected from -F, -Cl, -Br, and mixtures thereof when n′>1.