A method for producing a bipolar plate for a fuel cell stack includes the following steps: providing two half-plates made of sheet metal, which form the bipolar plate when arranged on top of one another, wherein the half-plates are profiled via deformation of the sheet metal, and wherein, as a result of the profiling, the two half-plates arranged on top of one another contact at at least one contact region and do not contact at at least one non-contact region; carrying out at least one first cut in the non-contact region of at least one half-plate, before the half-plates are arranged on top of one another; Arranging the two half-plates on top of one another and connecting same; and carrying out at least a second cut in the contact region through both half-plates after they have been arranged on top of one another and connected.

In a method of producing a fuel cell stack, press forming of a first metal separator of a power generation cell is performed to thereby form a first seal line as a seal around at least an oxygen-containing gas flow field. Further, a preliminary load is applied to the first seal line to thereby plastically deform the first seal line. Further, a joint separator and a membrane electrode assembly are stacked together, and a tightening load is applied to the joint separator and the membrane electrode assembly in a stacking direction, to thereby assemble the fuel cell stack.

In a method of producing a fuel cell stack, press forming of a first metal separator of a power generation cell is performed to thereby form a first seal line as a seal around at least an oxygen-containing gas flow field. Further, a preliminary load is applied to the first seal line to thereby plastically deform the first seal line. Further, a joint separator and a membrane electrode assembly are stacked together, and a tightening load is applied to the joint separator and the membrane electrode assembly in a stacking direction, to thereby assemble the fuel cell stack.

A fuel cell stack including: a metal-supported cell including a power generation cell formed of paired electrodes and an electrolyte sandwiched from both sides between the paired electrodes, and a metal supporting portion which is made of metal and which supports the power generation cell; a separator defining and forming a flow passage portion for gas flow between the separator and the power generation cell; a welded portion in which the metal-supported cell and the separator are welded to each other; a spring portion configured to apply absorption reaction force for absorbing displacement in a stacking direction in the welded portion to the metal-supported cell; and a stopper portion configured to restrict a displacement amount of the spring portion.

A fuel cell stack including: a metal-supported cell including a power generation cell formed of paired electrodes and an electrolyte sandwiched from both sides between the paired electrodes, and a metal supporting portion which is made of metal and which supports the power generation cell; a separator defining and forming a flow passage portion for gas flow between the separator and the power generation cell; a welded portion in which the metal-supported cell and the separator are welded to each other; a spring portion configured to apply absorption reaction force for absorbing displacement in a stacking direction in the welded portion to the metal-supported cell; and a stopper portion configured to restrict a displacement amount of the spring portion.

The plasma device includes a vessel with the first and second molds facing to each other. A work is sealed in the closed first and second molds. The work includes an object to be processed with a part to be processed and a part not to be processed on an outer periphery of the part to be processed, and a masking member covering the part not to be processed. The first mold includes a facing plane portion disposed facing an outer periphery surface of the work, a first recessed portion disposed facing the part to be processed and generating plasma, and a second recessed portion disposed facing the part not to be processed between the facing plane portion and the first recessed portion and generating plasma. A depth of the second recessed portion is different from a depth of the first recessed portion.

The plasma device includes a vessel with the first and second molds facing to each other. A work is sealed in the closed first and second molds. The work includes an object to be processed with a part to be processed and a part not to be processed on an outer periphery of the part to be processed, and a masking member covering the part not to be processed. The first mold includes a facing plane portion disposed facing an outer periphery surface of the work, a first recessed portion disposed facing the part to be processed and generating plasma, and a second recessed portion disposed facing the part not to be processed between the facing plane portion and the first recessed portion and generating plasma. A depth of the second recessed portion is different from a depth of the first recessed portion.

A fuel cell includes: a solid oxide electrolyte layer that has oxygen ion conductivity; an electrode layer that is provided on the solid oxide electrolyte layer; a separator that is provided on the electrode layer and is made of a metal material; and a sealing member that is provided from a circumference region of the solid oxide electrolyte layer to a circumference region of the dense metal layer, wherein the electrode layer, the separator and the sealing member demarcate at least a part of a gas passage, wherein at least a part of the sealing member is a mixed layer of a ceramic and a metal.

A fuel cell includes: a solid oxide electrolyte layer that has oxygen ion conductivity; an electrode layer that is provided on the solid oxide electrolyte layer; a separator that is provided on the electrode layer and is made of a metal material; and a sealing member that is provided from a circumference region of the solid oxide electrolyte layer to a circumference region of the dense metal layer, wherein the electrode layer, the separator and the sealing member demarcate at least a part of a gas passage, wherein at least a part of the sealing member is a mixed layer of a ceramic and a metal.

A fuel cell is formed by laminating a plurality of cells. Each cell includes a membrane electrode assembly and two separators, which hold the membrane electrode assembly in between. Each separator includes a base member made of a metal material. A first layer is provided on the surface of the base member. The first layer includes a resin film and conductive particles that have greater hardness than the oxide film of the base member. Between the separators that are adjacent to each other, the first layers are in contact with each other.