A fuel cell separator having high corrosion resistance and electrical conductivity is provided. This fuel cell separator includes, on a substrate, an antimony-doped tin oxide film having an alkyl group substituted with at least one fluorine atom, in which an element ratio of fluorine to tin (F/Sn) in the film is 3 or more and 7 or less.

A manifold plate for a fuel cell stack includes a lower manifold portion, an upper manifold portion, a dielectric layer sandwiched between the lower manifold portion and the upper manifold portion, a bottom inlet hole and a bottom outlet hole formed in a bottom surface of the lower manifold portion, where the bottom inlet hole and the bottom outlet hole extend through the dielectric layer, top outlet holes and top inlet holes formed in opposing sides of a top surface of the upper manifold portion, outlet channels fluidly connecting the top outlet holes to the bottom inlet hole, and inlet channels fluidly connecting the top inlet holes to the bottom outlet hole.

An alloy member includes a base member that includes a recess in a surface of the base member and is constituted by an alloy material containing chromium, an anchor portion is disposed in the recess and contains an oxide containing manganese and a covering layer is connected to the anchor portion and contains a low-equilibrium oxygen pressure element whose equilibrium oxygen pressure is lower than that of chromium.

A fuel cell stack includes: a substrate; a first fuel cell including a fuel side electrode, an electrolyte, and an oxygen side electrode on the substrate, the first fuel cell being a single fuel cell; a second fuel cell including a fuel side electrode, an electrolyte, and an oxygen side electrode on the substrate, the second fuel cell being a single fuel cell; an interconnector film electrically connecting the fuel side electrode of the first fuel cell and the oxygen side electrode of the second fuel cell; and a porous ceramic film covering at least the interconnector film in a region between the fuel side electrode of the first fuel cell and the fuel side electrode of the second fuel cell.

A fuel cell stack includes: a substrate; a first fuel cell including a fuel side electrode, an electrolyte, and an oxygen side electrode on the substrate, the first fuel cell being a single fuel cell; a second fuel cell including a fuel side electrode, an electrolyte, and an oxygen side electrode on the substrate, the second fuel cell being a single fuel cell; an interconnector film electrically connecting the fuel side electrode of the first fuel cell and the oxygen side electrode of the second fuel cell; and a porous ceramic film covering at least the interconnector film in a region between the fuel side electrode of the first fuel cell and the fuel side electrode of the second fuel cell.

In a first aspect of a present inventive subject matter, a multilayer structure includes a base with a surface and an electrically-conductive metal oxide film that is positioned directly or via another layer on the base. At least a part of the surface of the base contains as a major component at least one selected from the group of copper, copper alloy, aluminum, aluminum alloy, magnesium, magnesium alloy, and stainless steel. The electrically-conductive metal oxide film is 30 nm or more in thickness. The multilayer structure is electrically-conductive and has a contact resistance that is 100 mΩcm.sup.2 or less.

In a first aspect of a present inventive subject matter, a multilayer structure includes a base with a surface and an electrically-conductive metal oxide film that is positioned directly or via another layer on the base. At least a part of the surface of the base contains as a major component at least one selected from the group of copper, copper alloy, aluminum, aluminum alloy, magnesium, magnesium alloy, and stainless steel. The electrically-conductive metal oxide film is 30 nm or more in thickness. The multilayer structure is electrically-conductive and has a contact resistance that is 100 mΩcm.sup.2 or less.

The fuel cell of the present disclosure includes: a fuel single cell comprising a fuel electrode, an air electrode, and an electrolyte disposed between the electrodes; a separator for separating a fuel gas flowing through the fuel electrode and air flowing through the air electrode; and a sealing portion for hermetically bonding between the separator and the electrolyte, wherein the sealing portion is constituted of a glass composition containing at least two of metallic or metalloid elements contained in the electrolyte and at least two of metallic or metalloid elements contained in the separator; the electrolyte includes a proton conductor; and the proton conductor is represented by a compositional formula: BaZr.sub.1-xM.sub.xO.sub.3, where 0.05≤x≤0.5; and M is at least one selected from the group consisting of Sc, In, Lu, Yb, Tm, Er, Y, Ho, Dy, and/or Gd.

The fuel cell of the present disclosure includes: a fuel single cell comprising a fuel electrode, an air electrode, and an electrolyte disposed between the electrodes; a separator for separating a fuel gas flowing through the fuel electrode and air flowing through the air electrode; and a sealing portion for hermetically bonding between the separator and the electrolyte, wherein the sealing portion is constituted of a glass composition containing at least two of metallic or metalloid elements contained in the electrolyte and at least two of metallic or metalloid elements contained in the separator; the electrolyte includes a proton conductor; and the proton conductor is represented by a compositional formula: BaZr.sub.1-xM.sub.xO.sub.3, where 0.05≤x≤0.5; and M is at least one selected from the group consisting of Sc, In, Lu, Yb, Tm, Er, Y, Ho, Dy, and/or Gd.

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.