A gas diffusion layer, a preparation method therefor, a membrane electrode assembly and a fuel cell. The gas diffusion layer comprises gas diffusion layer substrates (41, 42) and a microporous layer slurry coated on the gas diffusion layer substrates (41, 42). An additive that contains catechol or contains a catechol structure compound is specifically added into the microporous layer slurry, and the additive is specifically dopamine hydrochloride.

A fuel cell with high productivity, high power generation performance and high durability is described, along with a gas diffusion electrode base material having a microporous layer on one side of an electrically conductive porous base material, where the electrically conductive porous base material contains carbon fiber and resin carbide and has a density of 0.25 to 0.39 g/cm.sup.3 and a pore mode diameter in a range of 30 to 50 μm. The microporous layer contains a carbonaceous powder and a fluororesin and has a surface roughness of 2.0 to 6.0 μm, a porosity of 50 to 95%, and a pore mode diameter of 0.050 to 0.100 μm.

An electrode material (1) for a fuel cell (50), comprising a planar body (11) made of an electrically conductive foam having an open and continuous porosity for at least one operating medium of the fuel cell (50), wherein the planar body (11) has a top side (12) and a bottom side (13), and wherein the thickness (14) of the material across all points (12a, 12a′) on the surface of the top side (12), measured in each case between a point (12a, 12a′) on the surface of the top side (12) and the point (13a, 13a′) opposite this point (12a, 12a′) on the surface of the bottom side (13), varies by at least 10%. An electrode (2) for a fuel cell (50), comprising a planar body (21) made of an electrically conductive foam having an open and continuous porosity for at least one operating medium of the fuel cell (50), wherein the planar body (21) has a top side (22) and a bottom side (23), and wherein the top side (22), and/or the bottom side (23), has regions (22a, 23a) in which the porosity of the planar body (11) is reduced by at least 10%. A fuel cell (50) comprising the electrode (2). A method for production.

A fuel cell includes a flow field plate having at least one channel and at least one land, where each of the at least one channel is positioned between two adjacent lands. The fuel cell further includes a gas diffusion layer (GDL) positioned between the flow field plate and a catalyst layer, where the catalyst layer has a first region aligned with the at least one channel and a second region aligned with the at least one land. The first region may have a first catalyst material supported by a first catalyst support region, and the second region may have a second catalyst material supported by a second catalyst support region.

A layered cathode structure for a molten carbonate fuel cell is provided, along with methods of forming a layered cathode and operating a fuel cell including a layered cathode. The layered cathode can include at least a first cathode layer and a second cathode layer. The first cathode layer can correspond to a layer that is adjacent to the molten carbonate electrolyte during operation, while the second cathode layer can correspond to a layer that is adjacent to the cathode collector of the fuel cell. The first cathode layer can be formed by sintering a layer that includes a conventional precursor material for forming a cathode, such as nickel particles. The second cathode layer can be formed by sintering a layer that includes a mixture of particles of a conventional precursor material and 1.0 vol % to 30 vol % of particles of a lithium pore-forming compound. The resulting layered cathode structure can have an increased pore size adjacent to the cathode collector to facilitate diffusion of CO.sub.2 into the electrolyte interface, while also having a smaller pore size adjacent to the electrolyte to allow for improved electrical contact and/or reduced polarization at the interface between the electrolyte and the cathode.

A solid oxide electrochemical device comprises a solid electrolyte layer, the first surface and second surface having surface pores formed therein; a first composite electrolyte layer composed of metal and a solid electrolyte and having a first porosity; a second composite electrolyte layer composed of metal and the solid electrolyte and having the first porosity, the solid electrolyte layer sandwiched between the first composite electrolyte layer and the second composite electrolyte layer; a cathode on one of the first composite electrolyte layer and the second composite electrolyte layer; and an anode on another of the first composite electrolyte layer and the second composite electrolyte layer. The anode comprises an anode metal layer comprising pores; anode active material; and reforming catalyst, wherein the anode active material and the reforming catalyst line walls of the pores in the anode metal layer.

A metal air battery apparatus includes: a metal air cell including a cathode layer including pores, an anode layer facing the cathode layer, and a solid electrolyte layer between the cathode layer and the anode layer; and a controller configured to control at least one of a charge rate or a discharge rate of the metal air cell based on a porosity of the cathode layer.

Disclosed are a method of manufacturing a membrane-electrode assembly and a membrane-electrode assembly manufactured using the same. The method includes forming a laminated structure, and treating the laminated structure, for example, by drying and heat treating. The laminated structure includes a release film, an anode layer, a porous support layer, and a cathode layer.

A method for production of a fuel cell includes:

a) Preparing a plurality of catalyst pastes which differ from each other at least in regard to one parameter influencing the catalytic activity,

b) Filling of at least two of the plurality of catalyst pastes into a first application means having a number of chambers corresponding to the number of catalyst pastes being filled, where only one of the catalyst pastes is filled into each of the chambers,

c) Filling of at least two of the plurality of catalyst pastes into a second application means having a number of chambers corresponding to the number of catalyst pastes being filled, where only one of the catalyst pastes is filled into each of the chambers,

d) Coating of a first side of a foil web of an electrolyte membrane which is moved past the first application means and the second application means by means of the first application means,

e) Coating of a second side of the foil web by means of the second application means,

f) Cutting of the resulting coated electrolyte membrane from the foil web and rotating of the electrolyte membrane by 90° with respect to a delivery direction of the foil web,

g) Placing of the electrolyte membrane between two flow field plates with a gradient in regard to the parameter which is oriented perpendicular to the flow field, and

h) Pressing together the flow field plates.

Materials for electrochemical cells are provided. BaZr.sub.0.4Ce.sub.0.4M.sub.0.2O.sub.3 compounds, where M represents one or more rare earth elements, are provided for use as electrolytes. PrBa.sub.0.5Sr.sub.0.5Co.sub.2−xFe.sub.xO.sub.5+δ is provided for use as a cathode. Also provided are electrochemical cells, such as protonic ceramic fuel cells, incorporating the compounds as electrolytes and cathodes.