Abstract: Monolayer ion-exchange membrane structured in the thickness comprising ion-exchange sites covalently bonded to a support polymer, the membrane comprising two surface zones located on either side of a mid-zone, each surface zone having a thickness of not more than 15% of the total thickness of the membrane, in which the surface zones have a mean ion-exchange site density Dsurface calculated on the thickness of the surface zones of at least Dtotal.

Abstract: Monolayer ion-exchange membrane structured in the thickness comprising ion-exchange sites covalently bonded to a support polymer, the membrane comprising two surface zones located on either side of a mid-zone, each surface zone having a thickness of not more than 15% of the total thickness of the membrane, in which the surface zones have a mean ion-exchange site density Dsurface calculated on the thickness of the surface zones of at least Dtotal.

Abstract: An alkali fuel cell comprises a solid stack consisting of a first electrode, a solid membrane conducting hydroxide ions and a second electrode, each electrode comprising an active layer that is in contact with the solid membrane. The material forming the active layer of each electrode comprises at least a catalytic element, an electronic conductive element and an element conducting hydroxide ions. The element conducting hydroxide ions is a polymer having vinylaromatic units comprising a quaternary ammonium function and a hydroxide ion OH? is associated with each quaternary ammonium function. One such alkali fuel cell is unaffected by carbonation and maintains good electrochemical performances.

Abstract: Monolayer ion-exchange membrane structured in the thickness comprising ion-exchange sites covalently bonded to a support polymer, the membrane comprising two surface zones located on either side of a mid-zone, each surface zone having a thickness of not more than 15% of the total thickness of the membrane, in which the surface zones have a mean ion-exchange site density Dsurface calculated on the thickness of the surface zones of at least Dtotal.

Abstract: An alkali fuel cell comprises a solid stack consisting of a first electrode, a solid membrane conducting hydroxide ions and a second electrode, each electrode comprising an active layer that is in contact with the solid membrane. The material forming the active layer of each electrode comprises at least a catalytic element, an electronic conductive element and an element conducting hydroxide ions. The element conducting hydroxide ions is a polymer having vinylaromatic units comprising a quaternary ammonium function and a hydroxide ion OH? is associated with each quaternary ammonium function. One such alkali fuel cell is unaffected by carbonation and maintains good electrochemical performances.

Abstract: A separator for an electrochemical generator is constituted by a microporous polyolefin film grafted with at least one monomer selected from diethyleneglycol dimethacrylate, furfuryl acrylate and a diethyleneglycol dimethacrylate/acrylic acid mixture. In a process for the production of a separator of this kind grafting of the monomer is carried out in three stages:irradiation of the film,if required, storage of the irradiated film,immersion of the irradiated film in the grafting solution comprising the monomer, a solvent, and at least one additive. The separator may be used in an electrochemical generator with either an aqueous or nonaqueous electrolyte where the salt concentration is between 1M and 2M.