H01M8/021

Stainless steel sheet for fuel cell separators and production method therefor
11085120 · 2021-08-10 · ·

A stainless steel sheet for fuel cell separators comprises a predetermined chemical composition, wherein the stainless steel sheet has a textured structure at a surface thereof, an average interval between projected parts of the textured structure being 20 nm or more and 200 nm or less, and 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 2.0 or more.

Cell unit

A cell unit CU includes a cell structure 1, a metal support plate 2 disposed on one side surface of the cell structure 1, and a frame 3 holding an outer peripheral part of the support plate 2. The cell structure 1 has a lamination of an anode electrode layer 4, an electrolyte layer 5, and a cathode electrode layer 6, in this order. The frame 3 includes a displacement guide 7 at least on one side surface of the frame 3. The displacement guide 7 has a coefficient of thermal expansion that is different from that of the frame 3 and is configured to make the frame 3 curve so that the cell structure 1 is concaved in accompany with thermal expansion. In the cell unit CU, a risk of concentration of tensile stress on the electrolyte layer 5 at the time of thermal expansion during operation is removed without reducing the strength of the frame 3, whereby occurrence of a crack and the like in the electrolyte layer 5 can be prevented beforehand.

AUSTENITIC STAINLESS STEEL HAVING EXCELLENT ELECTRICAL CONDUCTIVITY, AND METHOD FOR MANUFACTURING SAME
20210254203 · 2021-08-19 ·

The present disclosure relates to austenitic stainless steel with excellent electrical conductivity in which metal copper is formed in a non-conductive passivation film formed on the surface of stainless steel, and a method of manufacturing the same.

The austenitic stainless steel with excellent electrical conductivity according to an embodiment of present disclosure includes: a stainless steel base material comprising, in percent (%) by weight of the entire composition, C: 0.1% or less, Si: 0.1 to 1.0% or less, Mn: 0.1 to 2.0% or less, Cr: 15 to 24% or less, Ni: 6 to 12% or less, Cu: 0.5 to 3% or less, the remainder of iron (Fe) and other inevitable impurities; and a passivation film formed on the stainless steel base material, and the passivation film has a thickness of more than 0 and less than or equal to 5 nm, the Cu weight % content in the thickness region between 2 to 3 nm from the surface of the passivation film is 1.5 or more compared to the Cu weight % content of the stainless steel base material.

Alloy member

An alloy member includes a base member constituted by an alloy material containing chromium, a chromium oxide layer for covering at least a portion of a surface of the base member, a pore that is formed in an interface region of the base member that is located 30 μm or less from an interface between the chromium oxide layer and the base member, and an extending portion extending from the pore into the base member. The pore is configured to inhibit the separation of the chromium oxide layer from the base member The extending portion contains an oxide of an element whose equilibrium oxygen pressure is lower than that of a major element of the base member.

Fuel cell separator and method of manufacturing fuel cell separator
11843136 · 2023-12-12 · ·

The present invention is directed to a fuel cell separator 1 included in a fuel cell, and the fuel cell separator 1 includes: a substrate 11 made of stainless steel; a middle portion 30 including a power generating portion; and an outer peripheral portion 20 including a non-power generating portion. The middle portion 30 includes a dissimilar metal layer 12 different from the stainless steel included in the substrate on the substrate, and a carbon layer 13 provided on the dissimilar metal layer 12, and the outer peripheral portion 20 includes a portion including the dissimilar metal layer 12, the carbon layer 13, and a resin layer 14 on the carbon layer, and a portion not including the dissimilar metal layer 12 or the carbon layer 13, and including the resin layer 14 on the substrate.

Fuel cell separator and method of manufacturing fuel cell separator
11843136 · 2023-12-12 · ·

The present invention is directed to a fuel cell separator 1 included in a fuel cell, and the fuel cell separator 1 includes: a substrate 11 made of stainless steel; a middle portion 30 including a power generating portion; and an outer peripheral portion 20 including a non-power generating portion. The middle portion 30 includes a dissimilar metal layer 12 different from the stainless steel included in the substrate on the substrate, and a carbon layer 13 provided on the dissimilar metal layer 12, and the outer peripheral portion 20 includes a portion including the dissimilar metal layer 12, the carbon layer 13, and a resin layer 14 on the carbon layer, and a portion not including the dissimilar metal layer 12 or the carbon layer 13, and including the resin layer 14 on the substrate.

BATTERY CATHODES FOR IMPROVED STABILITY
20210305548 · 2021-09-30 ·

A lithium battery and method for fabricating the same are provided herein. The battery cathode comprises a carbon structure filled with a catalyst, such as palladium-catalyst-filled carbon nanotubes (CNTs). The carbon structure provides a barrier between the catalyst and the electrolyte providing an increased stability of the electrolyte during both discharging and charging of a battery.

METAL MEMBER AND MANUFACTURING METHOD THEREOF

There is provided a metal member capable of effectively preventing a coating layer from peeling off from a base. The metal member in an embodiment is a metal member that is used in a solid-oxide type electrochemical stack, and includes: a base formed of ferritic stainless steel; and a metal film provided on the base, in which the metal film includes a first metal layer containing Co and a second metal layer made of Mn, and is a stack in which the first metal layer and the second metal layer are sequentially stacked from the side of the base.

METAL MEMBER AND MANUFACTURING METHOD THEREOF

There is provided a metal member capable of effectively preventing a coating layer from peeling off from a base. The metal member in an embodiment is a metal member that is used in a solid-oxide type electrochemical stack, and includes: a base formed of ferritic stainless steel; and a metal film provided on the base, in which the metal film includes a first metal layer containing Co and a second metal layer made of Mn, and is a stack in which the first metal layer and the second metal layer are sequentially stacked from the side of the base.

Stainless steel for polymer fuel cell separator and method for preparing same

There are provided a ferrite stainless steel for a polymer fuel cell separator having excellent corrosion resistance and interfacial contact resistance under an operating environment of a polymer fuel cell, and a preparation method of the stainless steel. A stainless steel includes C: 0.02 wt % or less, N: 0.02 wt % or less, Si: 0.4 wt % or less, Mn: 0.2 wt % or less, P: 0.04 wt % or less, S: 0.02 wt % or less, Cr: 25.0 to 32.0 wt %, Cu: 0 to 2.0 wt %, Ni: 0.8 wt % or less, Ti: 0.5 wt % or less, Nb: 0.5 wt % or less, waste Fe and inevitably contained elements. A preparation method of the stainless steel having a second passive film formed on a surface thereof includes forming a first passive film on the surface of the stainless steel by bright-annealing or annealing-pickling the stainless steel; removing the first passive film by pickling the stainless steel in a 10 to 20 wt % sulfuric acid solution at a temperature of 50 to 75° C. for a predetermined time; water-washing the stainless steel; and forming the second passive film by performing a passivation treatment on the stainless steel in the mixture of a 10 to 20 wt % nitric acid and a 1 to 10 wt % fluorine acid at a temperature of 40 to 60° C. for the predetermined time. Accordingly, it is possible to prepare a stainless steel having reduced elution resistance and excellent corrosion resistance and to produce a stainless steel for a polymer fuel cell separator, which has low interfacial contact resistance and excellent long-term performance even under a fuel cell operating condition of 60 to 150° C. and various surface roughness conditions.