A redox flow battery may include: a membrane interposed between a first electrode positioned at a first side of the membrane and a second electrode positioned at a second side of the membrane opposite to the first side; a first flow field plate comprising a plurality of positive flow field ribs, each of the plurality of positive flow field ribs contacting the first electrode at first supporting regions on the first side; and the second electrode, including an electrode spacer positioned between the membrane and a second flow field plate, the electrode spacer comprising a plurality of main ribs, each of the plurality of main ribs contacting the second flow field plate at second supporting regions on the second side, each of the second supporting regions aligned opposite to one of the plurality of first supporting regions. As such, a current density distribution at a plating surface may be reduced.

A process for manufacturing a gas diffusion device includes providing a superposition of a composite layer and of an electrically conductive element, the composite layer including electrically conductive fibers and a polymerizable resin impregnating the conductive fibers, and the electrically conductive element having an open porosity between a first face and a second face. The process also includes compressing the superposition of the composite layer and of the conductive element so as to bring said conductive fibers into contact with the first face of the element, so as to make said resin flow into said element without the resin impregnating all the volume of said conductive element; and polymerizing the resin.

A process for manufacturing a gas diffusion device includes providing a superposition of a composite layer and of an electrically conductive element, the composite layer including electrically conductive fibers and a polymerizable resin impregnating the conductive fibers, and the electrically conductive element having an open porosity between a first face and a second face. The process also includes compressing the superposition of the composite layer and of the conductive element so as to bring said conductive fibers into contact with the first face of the element, so as to make said resin flow into said element without the resin impregnating all the volume of said conductive element; and polymerizing the resin.

An electrochemical device comprises a first type of membrane disposed between first and second reservoirs containing an input solution, and a second type of membrane, different from the first type, is disposed between a first redox-active electrolyte chamber and the first reservoir and disposed between a second redox-active electrolyte chamber and the second reservoir. The first type of membrane and one of the second type of membranes form a membrane pair and the pair has an area specific resistance below y=5065.3x.sup.3−1331.1x.sup.2+90.035x+39 Ohm cm.sup.2 when the pair is equilibrated in an electrolyte and for at least part of a range where 0<x<0.4 and x is the mass fraction of salt in the electrolyte.

The invention provides a gas diffusion layer for a fuel cell on which a microporous layer is disposed, which can have lower contact resistance with electrode catalyst layers and improved gas diffusion performance. The gas diffusion layer for a fuel cell of the disclosure has a conductive porous substrate layer and a microporous layer laminated in that order, wherein the microporous layer comprises carbon particles and a water-repellent resin, and has an impregnating portion that impregnates the conductive porous substrate layer and a non-impregnating portion that does not impregnate the conductive porous substrate layer, the thickness of the non-impregnating portion is greater than 0.0 μm and 20.0 μm or smaller, and the thickness of the impregnating portion is 29% or lower with respect to the total thickness of the microporous layer.

A gas diffusion electrode for a fuel cell which comprises a gas-permeable substrate that has functional groups is provided, said groups being capable of complexing cations, and catalytically active noble metal particles and/or atoms, said particles and/or atoms being bonded by the functional groups to a surface of a first flat side of the substrate and/or in a surface-proximal region of a first flat side of the substrate. The gas diffusion electrode according to the invention combines the functions of a gas diffusion layer and a catalytic layer in an integral component and is distinguished by a high long-term stability with respect to degradation phenomena of the catalyst.

A method for the preparation of a gas diffusion layer, containing the steps of: a) preparing a carrier-binder paste comprising a solvent, a fluorinated binder and conductive carrier articles; b) preparing an adhesive composition comprising a solvent, a fluorinated binder and essentially no or equal to or less than 15 wt. % of conductive carrier particles, based on the total weight of fluorinated binder and any conductive carrier particles; and c) combining a layer of supporting material, a layer of the adhesive composition and a layer of the carrier-binder paste, wherein the layer of the adhesive composition is applied between the layer of supporting material and the layer of the carrier-binder paste, and pressing the combination of supporting material, adhesive composition and carrier-binder paste at a pressure of at least 15 kilopascal and/or heating the combination of supporting material, adhesive composition and carrier-binder paste at a temperature of at least 300° C., and a gas diffusion layer so prepared.

A resin composition for a redox flow battery separator, and a method for producing a redox flow battery separator using same are provided. The resin composition includes: a polyolefin-based resin; a fumed silica; a compatibilizing agent including at least one selected from the group consisting of a maleic anhydride graft-polyethylene, a maleic acid graft-polyethylene, an alkyl maleate graft-polyethylene, a maleamic acid graft-polyethylene, and polyethylene oxide; and a pore former.

A separator for a redox flow battery and a manufacturing method are provided. The separator includes: a porous substrate; and an ionomer coating layer provided on at least one surface of the porous substrate, wherein the ionomer coating layer includes an ion conductive resin containing ion clusters having a diameter in the range of 3 nm<d.sub.c<6 nm, as measured by small-angle X-ray scattering (SAXS) in water at 25° C.

A separator for a redox flow battery and a manufacturing method are provided. The separator includes: a porous substrate; and an ionomer coating layer provided on at least one surface of the porous substrate, wherein the ionomer coating layer includes an ion conductive resin containing ion clusters having a diameter in the range of 3 nm<d.sub.c<6 nm, as measured by small-angle X-ray scattering (SAXS) in water at 25° C.