Abstract: A fuel cell and a method for regenerating this fuel cell, including a supply of the fuel cell by the main supply conduit by a fluid having a nominal flow rate and a nominal molar fraction of combustion agent, during a regeneration phase of a given group, a switching of the inlet, outlet and recirculation switches of the fluid circuit so as to supply the given group from the recirculation line of the given group and from a fluid discharge line of at least one other group, an application of a regeneration voltage Ve to the cells of the given group, Ve being less than or equal to 0.3V.

Abstract: A fuel cell and a method for regenerating this fuel cell, including a supply of the fuel cell by the main supply conduit by a fluid having a nominal flow rate and a nominal molar fraction of combustion agent, during a regeneration phase of a given group, a switching of the inlet, outlet and recirculation switches of the fluid circuit so as to supply the given group from the recirculation line of the given group and from a fluid discharge line of at least one other group, an application of a regeneration voltage Ve to the cells of the given group, Ve being less than or equal to 0.3V.

Abstract: A multilayer structure, of use as composite diffusion layer in a proton-exchange membrane fuel cell, including at least one mat of carbon nanotubes having a unit diameter of less than or equal to 20 nm, defining at least one face of the structure, the mat of carbon nanotubes being superposed on a support based on carbon fibres. It also relates to a process for preparing such a multilayer structure and to the use thereof for an electrode of a PEMFC.

Abstract: The present invention relates to a gas diffusion layer for a fuel cell, made of a carbon substrate grafted with at least one aromatic group having formula (II): wherein: the asterisk * designates a carbon atom with no hydrogen and no Ri group, with i=1 to 5, and covalently bonded to the carbon substrate; at least two of the R1, R2, R3, R4, and R5 groups are different from a hydrogen atom; at least two of the R1, R2, R3, R4, and R5 groups are hydrophobic groups or hydrophilic groups or a hydrophobic group and a hydrophilic group.

Abstract: A multilayer structure, of use as composite diffusion layer in a proton-exchange membrane fuel cell, including at least one mat of carbon nanotubes having a unit diameter of less than or equal to 20 nm, defining at least one face of the structure, the mat of carbon nanotubes being superposed on a support based on carbon fibres. It also relates to a process for preparing such a multilayer structure and to the use thereof for an electrode of a PEMFC.

Abstract: A membrane for a proton exchange membrane fuel cell including, by weight with respect to the total weight of the membrane: from 50 to 95% of polymer A; and from 5 to 50% by weight of polymer B; A being a cation exchange fluorinated polymer; and B being a hydrocarbon aromatic polymer different from polymer A, and comprising at least one aromatic ring on its polymer chain.

Abstract: A method for producing an array or bed of metallic nanotubes includes formation of nanowires made from sacrificial material on a growth support, deposition of a metal layer on the nanowires so as to form metallic nanotubes concentric with the nanowires, deposition of a polymer binding layer between the nanowires, elimination of the support, the binding layer supporting the metallic nanotubes, and etching of the sacrificial material.

Abstract: A membrane for a proton exchange membrane fuel cell including, by weight with respect to the total weight of the membrane: from 50 to 95% of polymer A; and from 5 to 50% by weight of polymer B; A being a cation exchange fluorinated polymer; and B being a hydrocarbon aromatic polymer different from polymer A, and comprising at least one aromatic ring on its polymer chain.

Abstract: A method of determining the electroosmotic transport coefficient of a proton exchange membrane, the method including creating a stream of hydrated hydrogen on either side of the membrane which is permanently controlled so that the relative humidity is almost identical on each side of the membrane at any point, thereby making it possible to minimize any back diffusion into the membrane. Furthermore, the method includes estimating the back diffusion flux into the membrane from the rate of return to equilibrium of the relative humidity starting from the moment when the current is cut off.

Abstract: A method for producing a diffusion layer of an electrochemical device, including: superimposition of multiple unidirectional webs of carbon filaments, filaments of each web positioned parallel with, and next to, one another; needle punching of the webs, breaking a proportion of the filaments such that broken portions of the filaments are tangled with other filaments of the webs; and cutting a proportion of the multiple unidirectional webs, the carbon filaments forming one electrically conducting outer surface of the diffusion layer. The needle punching is accomplished all the way through the multiple unidirectional webs, and/or through two principal opposite faces of the multiple unidirectional webs, and/or with an impact density against the multiple unidirectional webs of between approximately 100 and 300 impacts/cm2.

Abstract: Method of preparing a proton-exchange membrane for a fuel cell including placing in solution in a solvent a polymer selected from the group consisting of polymers having at least one monomer exhibiting a fluorinated group; adding at least one superacid to the polymer solution; mixing the solution; casting the solution containing the polymer and the superacid on a substrate; evaporating the solvent; and recovering the membrane. The used solvent is chemically stable in the presence of the superacid.

Abstract: Interpenetrating polymer networks comprising a first network of polymer A formed from monomers, at least one of which contains an aromatic group functionalized with a cation-exchange group, and a second network of polymer B formed from monomers, at least one of which contains a fluorinated group (RF). Use of these interpenetrating polymer networks for manufacturing fuel cell membranes.

Abstract: A method for producing an array or bed of metallic nanotubes includes formation of nanowires made from sacrificial material on a growth support, deposition of a metal layer on the nanowires so as to form metallic nanotubes concentric with the nanowires, deposition of a polymer binding layer between the nanowires, elimination of the support, the binding layer supporting the metallic nanotubes, and etching of the sacrificial material.

Abstract: A method of determining the electroosmotic transport coefficient of a proton exchange membrane, the method including creating a stream of hydrated hydrogen on either side of the membrane which is permanently controlled so that the relative humidity is almost identical on each side of the membrane at any point, thereby making it possible to minimize any back diffusion into the membrane. Furthermore, the method includes estimating the back diffusion flux into the membrane from the rate of return to equilibrium of the relative humidity starting from the moment when the current is cut off.

Abstract: A method for producing a diffusion layer of an electrochemical device, including: superimposition of multiple unidirectional webs of carbon filaments, filaments of each web positioned parallel with, and next to, one another; needle punching of the webs, breaking a proportion of the filaments such that broken portions of the filaments are tangled with other filaments of the webs; and cutting a proportion of the multiple unidirectional webs, the carbon filaments forming one electrically conducting outer surface of the diffusion layer. The needle punching is accomplished all the way through the multiple unidirectional webs, and/or through two principal opposite faces of the multiple unidirectional webs, and/or with an impact density against the multiple unidirectional webs of between approximately 100 and 300 impacts/cm2.

Abstract: The invention relates to a process for the formation of pores of controlled shape, dimensions and distribution in a polymer matrix comprising a step of embedding silicon nanowires and/or nanotrees in a nonpolymerized polymer matrix or a nonpolymerized polymer matrix in suspension or in solution in at least one solvent, a step of curing the polymer matrix, and a step of removing the silicon nanowires and/or nanotrees by chemical treatment. The process of the invention can be used for the manufacture of a proton exchange membrane fuel cell active layer. The invention has applications in the field of manufacture of proton exchange membrane fuel cells, in particular.

Abstract: Interpenetrating polymer networks comprising a first network of polymer A formed from monomers, at least one of which contains an aromatic group functionalized with a cation-exchange group, and a second network of polymer B formed from monomers, at least one of which contains a fluorinated group (RF). Use of these interpenetrating polymer networks for manufacturing fuel cell membranes.

Abstract: The invention relates to a process for the formation of pores of controlled shape, dimensions and distribution in a polymer matrix comprising a step of embedding silicon nanowires and/or nanotrees in a nonpolymerized polymer matrix or a nonpolymerized polymer matrix in suspension or in solution in at least one solvent, a step of curing the polymer matrix, and a step of removing the silicon nanowires and/or nanotrees by chemical treatment. The process of the invention can be used for the manufacture of a proton exchange membrane fuel cell active layer. The invention has applications in the field of manufacture of proton exchange membrane fuel cells, in particular.