An electrochemical reaction unit including a unit cell including an electrolyte layer, and a cathode and an anode that face each other in a first direction with the electrolyte layer intervening therebetween; and a felt member containing a ceramic material or a metal and a silica component. The felt member includes both a first crystal structure and a second crystal structure, which is an SiO.sub.2 crystal structure. Also disclosed is an electrochemical reaction cell stack including a plurality of electrochemical reaction units disposed in the first direction, at least one of the electrochemical reaction units being the above-described unit. Yet further disclosed is a method for producing the electrochemical reaction unit.

A power generation cell (fuel cell) includes a membrane electrode assembly and first and second metallic separators arranged respectively on opposite sides of the membrane electrode assembly. An oxygen containing gas supply passage, a communication passage bead section (bead seal) that surrounds the oxygen containing gas supply passage, and a bridge section are disposed on the first metallic separator. At a location where the bridge section is disposed, the width of a root section of the communication passage bead section is greater than the width of the root section of the communication passage bead section at other locations thereof.

A power generation cell (fuel cell) includes a membrane electrode assembly and first and second metallic separators arranged respectively on opposite sides of the membrane electrode assembly. An oxygen containing gas supply passage, a communication passage bead section (bead seal) that surrounds the oxygen containing gas supply passage, and a bridge section are disposed on the first metallic separator. At a location where the bridge section is disposed, the width of a root section of the communication passage bead section is greater than the width of the root section of the communication passage bead section at other locations thereof.

A metal bead seal with uniform sealing surface pressure and improved sealability is provided. A sealing bead is integrated with a basal part made of metal, and includes a curved part that is curved in a plan view and that includes a maximum bead width part having a maximum bead width w.sub.1, a straight part that is straight in a plan view and continuous from the curved part, the straight part including a minimum bead width part having a minimum bead width, a gradually varying bead width part that is positioned between the maximum bead width part and the minimum bead width part, the gradually varying bead width part having its bead width continuously varied from the maximum bead width to the minimum bead width.

A metal bead seal with uniform sealing surface pressure and improved sealability is provided. A sealing bead is integrated with a basal part made of metal, and includes a curved part that is curved in a plan view and that includes a maximum bead width part having a maximum bead width w.sub.1, a straight part that is straight in a plan view and continuous from the curved part, the straight part including a minimum bead width part having a minimum bead width, a gradually varying bead width part that is positioned between the maximum bead width part and the minimum bead width part, the gradually varying bead width part having its bead width continuously varied from the maximum bead width to the minimum bead width.

The fuel cell of the present disclosure includes: a unit cell including: a fuel electrode, an air electrode and electrolyte disposed between the fuel electrode and the air electrodes; a separator for separating a fuel gas flowing though the fuel electrode and air flowing through the air electrode; and a sealing constituted of a glass composition for bonding the separator and the electrolyte, and at least a surface region of the sealing portion exposed to the fuel gas and the air does not contain Ba.

The fuel cell of the present disclosure includes: a unit cell including: a fuel electrode, an air electrode and electrolyte disposed between the fuel electrode and the air electrodes; a separator for separating a fuel gas flowing though the fuel electrode and air flowing through the air electrode; and a sealing constituted of a glass composition for bonding the separator and the electrolyte, and at least a surface region of the sealing portion exposed to the fuel gas and the air does not contain Ba.

In various embodiments, components such as interconnects and/or endplates of a solid-state electrochemical device are coated with materials such as, for example, graphite, copper, aluminum, carbide ceramics, nitride ceramics, conversion coatings, or aluminum intermetallics.

In various embodiments, components such as interconnects and/or endplates of a solid-state electrochemical device are coated with materials such as, for example, graphite, copper, aluminum, carbide ceramics, nitride ceramics, conversion coatings, or aluminum intermetallics.

In various embodiments, components of a solid oxide fuel cell device such as interconnect plates, seals, and/or endplates may be composed of materials including aluminum, copper, and/or graphite.