A fuel cell separator having high corrosion resistance and electrical conductivity is provided. This fuel cell separator includes, on a substrate, a composite film containing an antimony-doped tin oxide and a tin-doped indium oxide, in which an element ratio of tin to indium (Sn/In) in the composite film is 1.4 or smaller.

A lamellar structure graphite foil is used as a material for a separator for a fuel cell, and a hydrophobic layer is formed by impregnation on flow-field channels of the graphite foil. Such a separator is manufactured by forming the flow field channel by etching the graphite foil formed with the mask pattern thereon and forming a hydrophobic layer by impregnation. According to such a separator, performance of a fuel cell stack is enhanced and the manufacturing process of a separator is simplified.

A lamellar structure graphite foil is used as a material for a separator for a fuel cell, and a hydrophobic layer is formed by impregnation on flow-field channels of the graphite foil. Such a separator is manufactured by forming the flow field channel by etching the graphite foil formed with the mask pattern thereon and forming a hydrophobic layer by impregnation. According to such a separator, performance of a fuel cell stack is enhanced and the manufacturing process of a separator is simplified.

Bipolar plate for assembling the elements of a fuel cell unit, consisting of a stainless-steel substrate (1) coated on at least one of the two faces thereof with a layer (5) of an electrically conductive material, characterised in that the material is selected from CrN and a bivalent or trivalent Ti compound or a mixture of such compounds, in that if the electrically conductive material is a bivalent or trivalent Ti compound or a mixture of such compounds, the layer (5) contains at most a quantity of oxygen in at. %, measured by X-ray photoelectron spectroscopy (XPS) on the upper 10 nm of the layer, which does not exceed 1.5 times the content in at. % of oxygen which, according to the measured content in at. % of Ti, would correspond to a coating which consists entirely of TiO, and in that at least one intermediate layer (4) of a metal or an alloy metal is positioned between the substrate (1) and the layer (5) of electrically conductive material, the thickness of the layer (4) of metal material being at least 1 nm over the entire surface of the substrate (1).

The invention also relates to a method for producing said bipolar plate, a fuel cell unit including same, and a fuel cell including said unit.

A method of making an interconnect for a solid oxide fuel cell stack includes contacting an interconnect powder located in a die cavity with iron, the interconnect powder including a chromium and iron, compressing the interconnect powder to form an interconnect having ribs and fuel channels on a first side of the interconnect, such that the iron is disposed on tips of the ribs; and sintering the interconnect, such that the iron forms an contact layer on the tips of the ribs having a higher iron concentration than a remainder of the interconnect. A glass containing cathode contact layer having a glass transition temperature of 900 C. or less may be located over the rib tips on the oxidant side of the interconnect.

A method of making an interconnect for a solid oxide fuel cell stack includes contacting an interconnect powder located in a die cavity with iron, the interconnect powder including a chromium and iron, compressing the interconnect powder to form an interconnect having ribs and fuel channels on a first side of the interconnect, such that the iron is disposed on tips of the ribs; and sintering the interconnect, such that the iron forms an contact layer on the tips of the ribs having a higher iron concentration than a remainder of the interconnect. A glass containing cathode contact layer having a glass transition temperature of 900 C. or less may be located over the rib tips on the oxidant side of the interconnect.

A bipolar plate for a fuel cell includes an anode plate and a cathode plate. The anode plate has hydrogen flow channels on a first side of the anode plate and coolant channels on a second side of the anode plate. The cathode plate has a first side disposed against the second side of the anode plate to cover the coolant channels and has a second side defining a recessed pocket configured to receive a stream of air. A flow guide is disposed in the pocket such that an inlet manifold is formed along a first edge of the flow guide and an outlet manifold is formed along a second edge of the flow guide. The flow guide defines channels extending from the inlet manifold to the outlet manifold. A plurality of openings is defined by through the flow guide.

A method of making an interconnect for a solid oxide fuel cell stack includes contacting an interconnect powder located in a die cavity with iron, the interconnect powder including a chromium and iron, compressing the interconnect powder to form an interconnect having ribs and fuel channels on a first side of the interconnect, such that the iron is disposed on tips of the ribs; and sintering the interconnect, such that the iron forms an contact layer on the tips of the ribs having a higher iron concentration than a remainder of the interconnect. A glass containing cathode contact layer having a glass transition temperature of 900 C. or less may be located over the rib tips on the oxidant side of the interconnect.

A method of making an interconnect for a solid oxide fuel cell stack includes contacting an interconnect powder located in a die cavity with iron, the interconnect powder including a chromium and iron, compressing the interconnect powder to form an interconnect having ribs and fuel channels on a first side of the interconnect, such that the iron is disposed on tips of the ribs; and sintering the interconnect, such that the iron forms an contact layer on the tips of the ribs having a higher iron concentration than a remainder of the interconnect. A glass containing cathode contact layer having a glass transition temperature of 900 C. or less may be located over the rib tips on the oxidant side of the interconnect.

A hydrocarbon-based cross-linked membrane used for the proton exchange membrane of a fuel cell, containing a cross-linked composite mediated by the sulfonate groups of SPPSU and SPOSS. Where SPPSU is represented by formula (I), where a, b, c, and d are each independently an integer of 0-4, and the total of a, b, c, and d is a rational number greater than 1 in terms of the average per repeating unit, and SPOSS is represented by formula (II), where each R is independently a hydrogen, a hydroxyl group, a straight or branched C1-20 alkyl or alkoxyl group optionally containing a substituent, or any of the above-mentioned structures, each e is independently an integer of 0-2 for R, x is an integer of 1-20, and the total number of sulfonate groups is a rational number greater than 2 in terms of the average per molecule. ##STR00001##