A gas diffusion layer for a fuel cell constituting a unit cell of the fuel cell includes a base layer including short carbon fibers and having a reinforcing portion formed in a predetermined area thereof in a thickness direction with continuous carbon fibers oriented in the reinforcing portion. One method of manufacturing the gas diffusion layer includes preparing a mixed dispersion in which short carbon fibers are mixed, orienting continuous carbon fibers on a conveyor belt, forming a paper having a reinforcing portion in which the continuous carbon fibers are oriented by supplying the prepared mixed dispersion to the conveyor belt on which the continuous carbon fibers are oriented, and forming a base layer by impregnating the paper with a hydrophobic agent.

A gas diffusion layer for a fuel cell constituting a unit cell of the fuel cell includes a base layer including short carbon fibers and having a reinforcing portion formed in a predetermined area thereof in a thickness direction with continuous carbon fibers oriented in the reinforcing portion. One method of manufacturing the gas diffusion layer includes preparing a mixed dispersion in which short carbon fibers are mixed, orienting continuous carbon fibers on a conveyor belt, forming a paper having a reinforcing portion in which the continuous carbon fibers are oriented by supplying the prepared mixed dispersion to the conveyor belt on which the continuous carbon fibers are oriented, and forming a base layer by impregnating the paper with a hydrophobic agent.

Disclosed are an electrode gas diffusion layer assembly (EGA) and a fuel cell stack including the same. The content of the binder in the electrode and the content of the binder in the adhesive layer that attaches the electrode to the gas diffusion layer (GDL) may be optimized. Thus, it is possible to reduce the occurrence of flooding and the deterioration in durability/performance caused by a dry atmosphere in the EGA including the electrode and the adhesive layer, so that the output density per unit area is improved while the trade-off is minimized.

Redox flow devices are described including a positive electrode current collector, a negative electrode current collector, and an ion-permeable membrane separating said positive and negative current collectors, positioned and arranged to define a positive electroactive zone and a negative electroactive zone; wherein at least one of said positive and negative electroactive zone comprises a flowable semi-solid composition comprising ion storage compound particles capable of taking up or releasing said ions during operation of the cell, and wherein the ion storage compound particles have a polydisperse size distribution in which the finest particles present in at least 5 vol % of the total volume, is at least a factor of 5 smaller than the largest particles present in at least 5 vol % of the total volume.

Redox flow devices are described including a positive electrode current collector, a negative electrode current collector, and an ion-permeable membrane separating said positive and negative current collectors, positioned and arranged to define a positive electroactive zone and a negative electroactive zone; wherein at least one of said positive and negative electroactive zone comprises a flowable semi-solid composition comprising ion storage compound particles capable of taking up or releasing said ions during operation of the cell, and wherein the ion storage compound particles have a polydisperse size distribution in which the finest particles present in at least 5 vol % of the total volume, is at least a factor of 5 smaller than the largest particles present in at least 5 vol % of the total volume.

A catalyst for an air electrode of a metal air secondary battery, the catalyst containing Ca.sub.2FeCoO.sub.5 and YBaCo.sub.4O.sub.7, in which a mass ratio of a content of the YBaCo.sub.4O.sub.7 to a content of the Ca.sub.2FeCoO.sub.5 is 0.49 to 9.00.

A membrane-electrode assembly includes an electrolyte membrane, a pair of catalyst layers stacked on surfaces of the electrolyte membrane, and a pair of gas diffusion layers stacked on a side opposite to the electrolyte membrane of one of the pair of catalyst layers and on a side opposite to the electrolyte membrane of the other one of the catalyst layers. One of the pair of catalyst layers contains catalyst particles and a first conductive material. One of the pair of gas diffusion layers in contact with the one of the catalyst layers contains a second conductive material. The first conductive material includes a first particulate conductive member and a first fibrous conductive member, and the second conductive material includes a second fibrous conductive member. The content K2 by mass of the second fibrous conductive member is larger than the content K1 by mass of the first fibrous conductive member.

The purpose of the present invention is to provide: a method for producing a gas diffusion electrode base which enables the achievement of a gas diffusion electrode base that has a microporous layer with small surface roughness and is not susceptible to damaging an electrolyte membrane; and a gas diffusion electrode base that has a microporous layer with small surface roughness and is not susceptible to damaging an electrolyte membrane. For the purpose of achieving the above-described purpose, the present invention has the configuration described below. Namely, a specific gas diffusion electrode base which has a carbon sheet and a microporous layer, and wherein the carbon sheet is porous and the DBP oil absorption of a carbon powder contained in the microporous layer is 70-155 ml/100 g.

An improved or advanced electrically conductive selectively gas permeable anode flow field (SGPFF) design, allowing for efficient removal of CO.sub.2 perpendicular to the active area near the location where it is formed in the catalyst layer. The anode plate design includes two mating flow fields (an anode gaseous flow field, and an anode liquid flow field) separated by a semi-permeable separator. The separator comprises a hydrophobic semi-permeable separator for CO.sub.2 diffusive gas transport from the liquid side (with acid, water, and CO.sub.2) to the gaseous side (allowing for CO.sub.2 removal to the atmosphere).

An alkali polysulphide flow battery, components, systems and compositions for use with an alkali polysulphide flow battery and a method of manufacturing and operating a flow battery system are provided. An ion-selective separator composition for a battery having an anode and an alkali metal sulfide or polysulfide cathode is provided. The separator composition includes an alkali metal ion conducting separator film for separating the anode and the cathode, a carbon layer disposed to a cathode side of the film and an alkali metal ion conductor layer disposed to an anode side of the carbon layer.