Methods for fabricating an interconnect for a fuel cell stack that include providing a protective layer over at least one surface of an interconnect formed by powder pressing pre-alloyed particles containing two or more metal elements and annealing the interconnect and the protective layer at elevated temperature to bond the protective layer to the at least one surface of the interconnect.

Methods for fabricating an interconnect for a fuel cell stack that include providing a protective layer over at least one surface of an interconnect formed by powder pressing pre-alloyed particles containing two or more metal elements and annealing the interconnect and the protective layer at elevated temperature to bond the protective layer to the at least one surface of the interconnect.

A substrate stainless steel sheet has [chemical form other than metal (Cr+Fe)]/[metal form (Cr+Fe)] of 12.0 or more and 200 or less, [chemical form other than metal (Cr+Fe)]/[metal form (Cr+Fe)] being a ratio of a total of Cr and Fe existing in chemical form other than metal to a total of Cr and Fe existing in metal form at a substrate stainless steel sheet surface.

A substrate stainless steel sheet has [chemical form other than metal (Cr+Fe)]/[metal form (Cr+Fe)] of 12.0 or more and 200 or less, [chemical form other than metal (Cr+Fe)]/[metal form (Cr+Fe)] being a ratio of a total of Cr and Fe existing in chemical form other than metal to a total of Cr and Fe existing in metal form at a substrate stainless steel sheet surface.

A coating for a bipolar plate of a fuel cell or an electrolyzer contains a homogeneous or heterogeneous solid metal solution. The coating contains at least 15% Iridium and up to 84% Ruthenium with a total combined concentration of Iridium and Ruthenium of at least 99% (atomic). The coating also contains at least one of Nitrogen, Carbon, and Flourine. The coating may contain traces of Oxygen or Hydrogen. The coating may be used as part of a layer system that includes one or more undercoat layers and the coating as a covering layer.

A coating for a bipolar plate of a fuel cell or an electrolyzer contains a homogeneous or heterogeneous solid metal solution. The coating contains at least 15% Iridium and up to 84% Ruthenium with a total combined concentration of Iridium and Ruthenium of at least 99% (atomic). The coating also contains at least one of Nitrogen, Carbon, and Flourine. The coating may contain traces of Oxygen or Hydrogen. The coating may be used as part of a layer system that includes one or more undercoat layers and the coating as a covering layer.

The present invention relates to a bipolar plate for a low-temperature fuel cell, in particular for a polymer electrolyte fuel cell, including a metal substrate with a coating on a surface of the substrate, the coating including an organic polymer and an electroconductive filler. The organic polymer is formed by chemical reaction of at least two components, including a bi- or polyfunctional isocyanate compound as the first component and one or more compounds having at least two free hydroxy or amino groups, as the second component.

Provided is a protective-layer-coated-interconnector, a cell stack, and a fuel cell. A component (particularly Cr) of the interconnector is prevented from diffusing even if the interconnector is exposed to high temperature for a long time. The interconnector has sufficient diffusion barrier-performance and protective performance.

[Solution] A protective-layer-coated-interconnector, a cell stack including the interconnector, and a fuel cell including the interconnector, wherein the interconnector includes an interconnector material and a protective layer on the surface of the interconnector material, wherein the interconnector material is composed of a Fe—Cr alloy containing a rare earth element or a Zr element in a total amount of 1.0 weight % or less, and wherein the protective layer is composed of a Co oxide or an oxide containing: at least one element selected from the group consisting of Al, Ti, Cr, Fe, Ni, Cu, and Zn; and a Co element.

The present disclosure relates to a method of producing a separator for a fuel cell in which layers having corrosion resistance and conductivity are formed on a stainless steel base material, the method including (i) a process of removing a passive layer on a surface of a stainless steel base material to obtain a stainless steel base material from which the passive layer has been removed, (ii) a process of forming layers having corrosion resistance and conductivity on the surface of the stainless steel base material from which the passive layer has been removed to obtain a corrosion-resistant conductive layer-deposited stainless steel base material, and (iii) a process of annealing the corrosion-resistant conductive layer-deposited stainless steel base material in a temperature range of 250° C. or higher and lower than 550° C. under conditions of oxygen being contained.

The present disclosure relates to a method of producing a separator for a fuel cell in which layers having corrosion resistance and conductivity are formed on a stainless steel base material, the method including (i) a process of removing a passive layer on a surface of a stainless steel base material to obtain a stainless steel base material from which the passive layer has been removed, (ii) a process of forming layers having corrosion resistance and conductivity on the surface of the stainless steel base material from which the passive layer has been removed to obtain a corrosion-resistant conductive layer-deposited stainless steel base material, and (iii) a process of annealing the corrosion-resistant conductive layer-deposited stainless steel base material in a temperature range of 250° C. or higher and lower than 550° C. under conditions of oxygen being contained.