An austenitic stainless steel sheet for fuel cell separators comprises a textured structure at a surface of the stainless steel sheet, the textured structure having recessed parts and projected parts, an average height of the projected parts being 30 nm or more and 300 nm or less, and an average interval between the projected parts being 20 nm or more and 350 nm or less, wherein a ratio [Cr]/[Fe] of an atomic concentration of Cr existing in chemical form other than metal to an atomic concentration of Fe existing in chemical form other than metal at the surface of the stainless steel sheet is 1.0 or more.

An austenitic stainless steel sheet for fuel cell separators comprises a textured structure at a surface of the stainless steel sheet, the textured structure having recessed parts and projected parts, an average height of the projected parts being 30 nm or more and 300 nm or less, and an average interval between the projected parts being 20 nm or more and 350 nm or less, wherein a ratio [Cr]/[Fe] of an atomic concentration of Cr existing in chemical form other than metal to an atomic concentration of Fe existing in chemical form other than metal at the surface of the stainless steel sheet is 1.0 or more.

Disclosed is an electrochemical cell with ceramic components having a ceramic/metal gradient below a ceramic outer layer.

A stainless steel substrate used for a fuel cell separator that is excellent in corrosion resistance is disclosed. The embodiments relate to a stainless steel substrate used for a fuel cell separator, comprising substantially no Nb, and comprising Ti.

Improved contact between interconnect and oxygen electrode material is achieved through a contact point between an electrode or a contact layer and a coated ferritic stainless steel interconnect, where the coating on the metallic interconnect comprises Cu.

Improved contact between interconnect and oxygen electrode material is achieved through a contact point between an electrode or a contact layer and a coated ferritic stainless steel interconnect, where the coating on the metallic interconnect comprises Cu.

The bipolar plate of the invention for electrochemical cells, especially for proton-exchange membrane (PEM) fuel cells, is made with a metallic substrate and on the surface is made with an electrical contact resistance-reducing, carbon-based layer, a layer system or a boundary layer which is made of a near-surface, primarily sp2-bonded, carbon-based layer having a carbon fraction ranging from 50% to 100%, this layer being applied on a metallic substrate surface that is modified relative to the starting material. There may also be a surface region of the substrate in the form of an edge layer made with nitride and/or carbon by nitriding and/or carburizing. On the surface which is in touching contact with a gas-permeable element within the electrochemical cell, the metallic substrate may have a structuring made with elevations and/or depressions in the respective surface.

Disclosed is a method of manufacturing a stainless steel with excellent contact resistance for a polymer fuel cell separator. The method of manufacturing a stainless steel with excellent contact resistance for a polymer fuel cell separator according to an embodiment of the present disclosure includes: electrolyzing to remove a first passivation film formed on a cold-rolled thin sheet of a stainless steel comprising, in percent (%) by weight of the entire composition, C: greater than 0 to 0.1%, N: greater than 0 to 0.02%, Si: greater than 0 to 0.25%, Mn: greater than 0 to 0.2%, P: greater than 0 to 0.04%, S: greater than 0 to 0.02%, Cr: 22 to 34%, Ti: greater than 0 to 0.5%, Nb: greater than 0 to 0.5%, the remainder of iron (Fe) and other inevitable impurities; and immersing in a mixed acid solution of nitric acid and hydrofluoric acid to form a second passivation film on the stainless cold-rolled thin sheet.

Disclosed is a method of manufacturing a stainless steel with excellent contact resistance for a polymer fuel cell separator. The method of manufacturing a stainless steel with excellent contact resistance for a polymer fuel cell separator according to an embodiment of the present disclosure includes: electrolyzing to remove a first passivation film formed on a cold-rolled thin sheet of a stainless steel comprising, in percent (%) by weight of the entire composition, C: greater than 0 to 0.1%, N: greater than 0 to 0.02%, Si: greater than 0 to 0.25%, Mn: greater than 0 to 0.2%, P: greater than 0 to 0.04%, S: greater than 0 to 0.02%, Cr: 22 to 34%, Ti: greater than 0 to 0.5%, Nb: greater than 0 to 0.5%, the remainder of iron (Fe) and other inevitable impurities; and immersing in a mixed acid solution of nitric acid and hydrofluoric acid to form a second passivation film on the stainless cold-rolled thin sheet.

The invention relates to a component (8) comprising a substrate made of chromia-former metal alloy (82), the basic element of which is iron (Fe) or nickel (Ni), wherein the substrate has two main planar faces. According to the invention: one of the main planar faces is coated with a coating comprising a thick layer of ceramic (80), grooved to delimit channels (800) suitable for the distribution and/or collection of gases, such as H.sub.2O water vapour, H.sub.2 or air, and/or one of the main planar faces is coated with a thick metal layer (81), grooved to delimit channels (810) suitable for the distribution and/or collection of gases, such as H.sub.2O water vapour, H.sub.2, O.sub.2 or draining gas. The invention also relates to the associated production processes.