A cathode configured to use oxygen as a cathode active material includes: a porous film including a metal oxide, where a porosity of the porous film is about 50 volume percent to about 95 volume percent, based on a total volume of the porous film, and an amount of an organic component in the porous film is 0 to about 2 weight percent, based on a total weight of the porous film.

In some implementations, a metal air battery includes a body defined by a metal anode and a cathode, a first separator layer disposed on the metal anode, a second separator layer disposed on the cathode, and a plurality of beads disposed within the body. The beads may confine a liquid electrolyte, and may be configured to release the liquid electrolyte into interior portions of the battery in response to a compression of the cathode into the body of the battery.

A positive electrode configured to use oxygen as a positive active material, and a barrier layer disposed on a surface of the porous layer, wherein a porosity of the porous layer is greater than a porosity of the barrier layer, wherein the barrier layer includes a first lithium-containing metal oxide; a lithium-air battery including the positive electrode; and a method of manufacturing the positive electrode.

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.

A method for making an improved fuel cell using a porosity gradient design for gas diffusion layers in a hydrogen fuel cell, a gas diffusion layer made by the method and a fuel cell containing the gas diffusion layer.

An electrochemical cell cathode catalyst layer includes electrocatalyst particles, an electrocatalyst support having an electronically conductive porous material including a plurality of pores with a diameter of less than or equal to 10 nm having a surface morphology comprising a plurality of peaks and valleys, the surface morphology being configured to contain the electrocatalyst particles within the plurality of pores and to enhance mass transport of molecular oxygen to the electrocatalyst particles by adsorbing molecular oxygen to the surface morphology, and an ionomer adhered to the electrocatalyst, the electrocatalyst support, or both.

A solid oxide fuel cell includes: a support layer mainly composed of a metal; an anode supported by the support; and a mixed layer interposed between the support and the anode, wherein the anode includes an electrode bone structure composed of a ceramic material containing a first oxide having electron conductivity and a second oxide having oxygen ion conductivity, and the mixed layer has a structure in which a metallic material and a ceramic material are mixed.

The invention relates to a composite multilayer carbon dioxide (CO.sub.2) reduction catalyst, comprising a catalyst layer comprising at least one metal compound, the catalyst layer having opposed first and second sides; a hydrophobic gas-diffusion layer provided on the first side of the catalyst layer; a current collection structure provided on the second side of the catalyst layer. The metal is preferably copper. The invention also relates to a method for electrochemical production of a hydrocarbon product, such as ethylene, using said catalyst.

An electrode structure of a flow battery, a flow battery stack, and a sealing structure of the flow battery stack, wherein the density of the vertical tow in the electrode fiber is larger than the density of the parallel tow. In the electrode fiber per unit volume, the quantity ratio of the vertical tow to the parallel tow is at least 6:4. The electrode structure is composed of an odd number of layers of the electrode fibers, and the porosity of other layers is larger than the porosity of the center layer. The electrode structure is mainly composed of the vertical tows perpendicular to the surface of the electrode, so that, firstly, the contact area between the outer surface of the electrode and the adjacent component can be increased and the contact resistance can be reduced, secondly, the electrode is endowed with good mechanical properties, compared with the original structure, the contact resistance of such structure is reduced by 30%-50%; and the layers of the electrode have different thickness depending on the porosity, after compression, the layers with optimized thickness have a consistent porosity, this compressed uniform structure avoids uneven mass transfer phenomena when the electrolyte flows through the electrode, and reduces the concentration polarization of the battery and thereby improving the battery energy output under the given power.

A cathode structure of a fuel cell is disclosed. The cathode structure comprises a cathode diffusion layer, wherein an air permeability adjusting structure is arranged around the cathode diffusion layer, and the cathode air permeability of the air permeability adjusting structure gradually varies in the flow direction of fluid. According to the cathode structure of a fuel cell, by means of arranging the air permeability adjusting structure, with variable cathode air permeability around the cathode diffusion layer, the difference caused by different temperatures and humidity is subtly compensated for, thus improving the problem of water accumulation or dehydration in a cathode structure of a fuel cell, and effectively improving the water management of the fuel cell.