Membrane electrode assembly for PEM fuel cells, including a proton exchange membrane, two catalyst layers (anode and cathode catalyst layer), and two gas diffusion layers, the anodic one of which is based on a carbon fiber paper and is provided with a microporous layer including graphite, carbon nanotubes or carbon nanofibers, and PTFE, whereas the cathodic gas diffusion layer is based on a carbon fiber structure and is provided with a microporous layer based on carbon black, carbon nanotubes and/or carbon nanofibers, and PTFE.

A membrane electrode assembly including: an anode electrode; a cathode electrode; and a polymer electrolyte membrane; wherein the cathode includes a first cathode catalyst sublayer including a first precious metal catalyst composition and a first ionomer composition including a first ionomer and a second ionomer; and a second cathode catalyst sublayer including a second precious metal catalyst composition and a second ionomer composition including a third ionomer; wherein the first ionomer is different from the second ionomer in at least one of chemical structure and equivalent weight.

A membrane electrode assembly includes a membrane, an anode catalyst layer and a cathode catalyst layer. The anode catalyst layer is on a first side of the membrane and the cathode catalyst layer is on a second side of the membrane, wherein the second side of the membrane is opposite the first side of the membrane along a first axis. The cathode catalyst layer includes agglomerates formed of a catalyst support supporting catalyst particles, an agglomerate ionomer and an inter-agglomerate ionomer. The agglomerate ionomer surrounds the agglomerates and the inter-agglomerate ionomer is in regions between the agglomerates surrounded by the agglomerate ionomer. The agglomerate ionomer is different than the inter-agglomerate. Methods to produce the catalyst layer are also provided.

An electrode, in particular a gas diffusion electrode, for a metal-oxygen battery. To achieve an improved performance output, e.g., an improved energy density or an improved capacity, the electrode includes a porous carrier substrate on which a porous active material is situated, the electrode having a gradient of medium pore sizes between the carrier substrate and the active material. Also described is an energy store including the electrode as described.

It becomes easy to regulate the storage modulus of the ionomer solution to be not lower than 150 Pa. The production method of catalyst ink for fuel cell includes steps of: (i) preparing a catalyst dispersion by mixing an electrode catalyst, water and an alcohol; (ii) preparing a gelated ionomer solution by mixing an ionomer and a solvent; and (iii) producing catalyst ink by mixing the catalyst dispersion and the gelated ionomer solution, wherein the step (ii) comprises concentration a step of concentrating the gelated ionomer solution.

Methods and compositions for making fuel cell components are described. In one embodiment, the method comprises providing a substrate, and forming or adhering an electrode on the substrate, wherein the forming includes depositing an aqueous mixture comprising water, a water-insoluble component, a catalyst, and an ionomer. The water-insoluble component comprises a water-insoluble alcohol, a water-insoluble carboxylic acid, or a combination thereof. The use of such water-insoluble components results in a stable liquid medium with reduced reticulation upon drying, reduced dissolution of the substrate, and reduced penetration of the pores of the substrate.

A fuel cell includes: a membrane electrode gas diffusion layer assembly in which a membrane electrode assembly is sandwiched by a pair of gas diffusion layers; an insulating member formed into a frame shape, and being in contact with an outer peripheral portion of the membrane electrode gas diffusion layer assembly; and first and second separators sandwiching the membrane electrode gas diffusion layer assembly and the insulating member.

An example of a stable electrode structure is to use a gradient electrode that employs large platinum particle catalyst in the close proximity to the membrane supported on conventional carbon and small platinum particles in the section of the electrode closer to a GDL supported on a stabilized carbon. Some electrode parameters that contribute to electrode performance stability and reduced change in ECA are platinum-to-carbon ratio, size of platinum particles in various parts of the electrode, use of other stable catalysts instead of large particle size platinum (alloy, etc), depth of each gradient sublayer. Another example of a stable electrode structure is to use a mixture of platinum particle sizes on a carbon support, such as using platinum particles that may be 6 nanometers and 3 nanometers. A conductive support is typically one or more of the carbon blacks.

The present invention provides a system for the manufacture of membrane electrode assemblies, comprising: a first carriage traversable along a first track, the first carriage having a support platform; a second carriage traversable along a second track, the second carriage having a support platform; sheet supplying means for supplying sheets comprising a gas diffusion layer onto the support platforms of the carriages; and supply means for supplying a continuous web comprising an ion-conducting membrane between at least a portion of the first and second tracks, wherein the system is arranged to align the first and second carriages either side of the continuous web with the support platforms of the first and second carriages facing the continuous web, whereby the system is suitable for adhering sheets carried thereby to opposite sides of the continuous web in an aligned configuration.

Provided a gas diffusion layer for fuel cells, the gas diffusion layer including: a carbon substrate; and a microporous layer formed on the carbon substrate, wherein the microporous layer comprises first carbon particles having a partially graphitized structure and a water-repellent binder resin binding the first carbon particles, and the microporous layer further comprises a cerium compound, a nitrogen-doped cerium compound, nitrogen-doped second carbon particles having a partially graphitized or non-graphitized structure, or a mixture of two or more, as a radical scavenger capable of removing hydrogen peroxide generated at a fuel cell open circuit potential or a higher potential. In the membrane electrode assembly and the fuel cell each employing the gas diffusion layer having excellent durability according to one or more embodiments, chemical or electrochemical degradation may be effectively prevented over a long period of time, and thus excellent electrochemical performance may be obtained over a long period of time. This leads to an extended lifetime of the fuel cell.