Abstract: The present invention discloses a metal separator for a fuel cell including a reaction gas channel formed to protrude from a first face of the metal separator to a second face thereof, a coolant channel formed between the reaction gas channels protruding from the second face of the metal separator, a reaction gas manifold opened to introduce a reaction gas into the metal separator, a coolant manifold opened to introduce a coolant into the metal separator, and a stepped portion positioned at any one of the space between the reaction gas channel and the reaction gas manifold, and the reaction gas channel. This configuration serves to widen the reaction gas flowing portion and the coolant flowing portion on the metal separator, and prevent deformation of the reaction gas flowing portion and the coolant flowing portion, thereby improving efficiency of the fuel cell.

Abstract: Disclosed herein is a method for manufacturing a metal steel separator for fuel cells that has corrosion resistance and contact resistance not only at an initial stage but also after being exposed to high temperature/high humidity conditions in the fuel cell for a long period of time. The method includes preparing a stainless steel sheet as a matrix of the metal separator, forming a discontinuous coating film on the surface of the stainless steel sheet, the coating film being composed of at least one selected from gold (Au), platinum (Pt), ruthenium (Ru), iridium (Ir), ruthenium oxide (RuO2), and iridium oxide (IrO2), and heat treating the stainless steel sheet having the discontinuous coating film to form an oxide film on a portion of the stainless steel sheet on which the coating film is not formed. A metal separator for fuel cells manufactured by the method is also disclosed.

Abstract: Disclosed herein is an air-cooled metal separator that does not need cooling water. The air-cooled metal separator includes a channel section formed in the middle of a metal plate, the channel section including a reaction gas channel depressed into a front surface of the metal plate to protrude from a rear surface thereof and an air channel defined between the reaction gas channels protruding from the rear surface of the metal plate; a first gasket continuously formed along a rim of a front surface of the channel section; and a second gasket discontinuously formed along a rim of a rear surface of the channel section to allow a discontinuous portion of the second gasket to provide a flow passage of air.

Abstract: Disclosed herein is a method of manufacturing a stainless steel separator for a fuel cell. The stainless steel separator includes a stainless steel sheet, a first coating layer comprising metal/metal nitride films (M/MNx) (0.5?x?1) on a surface of the stainless steel sheet, and a second coating layer comprising a metal oxynitride film (MOyNz) (0.05?y?2, 0.25?z?1.0).

Abstract: Disclosed are a metal separator for fuel cells, which exhibits excellent properties in terms of corrosion resistance, electrical conductivity and durability, and a method of manufacturing the same. The metal separator for fuel cells includes a separator-shaped metal matrix and a coating layer formed on the metal matrix. The coating layer has a concentration gradient of a carbon element C and a metal element Me according to a thickness thereof such that the carbon element C becomes gradually concentrated in the coating layer with increasing distance from the metal matrix, and the metal element Me becomes gradually concentrated in the coating layer with decreasing distance from the metal matrix.

Abstract: Disclosed herein is a stainless steel separator for a fuel cell and method of manufacture. The stainless steel separator includes a stainless steel sheet, a first coating layer comprising metal/metal nitride films (M/MNx) (0.5?x?1) on a surface of the stainless steel sheet, and a second coating layer comprising a metal oxynitride film (MOyNz) (0.05?y?2, 0.25?z?1.0).

Abstract: Disclosed herein is a method of manufacturing a metallic bipolar plate for fuel cells, which can maintain good corrosion resistance and contact resistance without any side effect not only initially but also after a predetermined period of time even in an environment of severe vibration as in vehicles while allowing a continuous process to provide high productivity.

Abstract: A method for surface treatment of a stainless steel separator for a fuel cell comprises preparing a stainless steel sheet containing nickel, chrome and iron, and having a passive film on a surface of the stainless steel sheet, and dipping the stainless steel sheet into a mixed etching solution of nitric acid (HNO3) and sulfuric acid (H2SO4) at a temperature of 50-70° C. for 30 seconds to 30 minutes to selectively lower an amount of Fe in the passive film formed on the surface of the stainless steel sheet.

Abstract: The present invention discloses a metal separator for a fuel cell including a reaction gas channel formed to protrude from a first face of the metal separator to a second face thereof, a coolant channel formed between the reaction gas channels protruding from the second face of the metal separator, a reaction gas manifold opened to introduce a reaction gas into the metal separator, a coolant manifold opened to introduce a coolant into the metal separator, and a stepped portion positioned at any one of the space between the reaction gas channel and the reaction gas manifold, and the reaction gas channel. This configuration serves to widen the reaction gas flowing portion and the coolant flowing portion on the metal separator, and prevent deformation of the reaction gas flowing portion and the coolant flowing portion, thereby improving efficiency of the fuel cell.

Abstract: A stainless steel separator for fuel cells and a method of manufacturing the same are disclosed. The method includes preparing a stainless steel sheet as a matrix, performing surface modification on a surface of the stainless steel sheet to form a Cr-rich passive film having a comparatively increased amount of Cr in a superficial layer of the stainless steel sheet by decreasing an amount of Fe in the superficial layer of the stainless steel sheet, and forming a coating layer on the surface of the surface-modified stainless steel sheet. The coating layer is one selected from a metal nitride layer (MNx), a metal/metal nitride layer (M/MNx), a metal carbide layer (MCy), and a metal boride layer (MBz) (where 0.5?x?1, 0.42?y?1, 0.5?z?2).