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.

[Object] To provide a cell stack device, the power generation efficiency of which is improved, and a fuel cell module and a fuel cell device that include the cell stack device. [Solution] A cell stack device 1 includes a cell stack 2 that includes a plurality of fuel cells 3 electrically connected to one another and arranged, the fuel cells 3 that each includes a gas channel through which a reactant gas flows. In the cell stack device 1, the fuel cells 3 of the cell stack 2 are provided in the form of fuel cell groups that each include an arbitrary number of the fuel cells 3. In the cell stack device 1, the fuel cell groups are arranged such that average pressure loss values of the fuel cells 3 of the fuel cell groups increase sequentially from a central portion to an end portion side in a fuel cell 3 arrangement direction. Thus, the power generation efficiency of the cell stack device 1 can be improved.

A cell includes an element portion including a first electrode layer, a solid electrolyte layer that contains Zr and that is located above the first electrode layer, an intermediate layer that contains CeO.sub.2 containing a rare earth element other than Ce and that is located above the solid electrolyte layer, and a second electrode layer located above the intermediate layer. The intermediate layer includes a first intermediate layer and a second intermediate layer that contains Zr and Ce and that is located at at least a portion between the first intermediate layer and the solid electrolyte layer. In a plan view from the second electrode layer, the second intermediate layer located at an outer peripheral portion of the intermediate layer includes a portion with a thickness greater than the second intermediate layer overlapping a center of the second electrode layer. A cell stack device, a module, and a module housing device include a plurality of the cells.

Provided are a metal plate configured such that sufficient strength and performance are ensured and the workability and cost of mass production are improved, and an electrochemical element and the like including the metal plate. A metal plate 1 includes a thick portion 110, and a thin portion 120 that is thinner than the thick portion 110. The thin portion 120 is provided with a penetration space 1c passing through the thin portion 120 in the thickness direction.

Provided is a highly reliable fuel cell that improves power generation efficiency of the fuel cell and that is less likely to cause damage to an electrode and an electrolyte film. The fuel cell includes a support substrate (2, 3) having a region in which a support portion having a mesh-like shape in a plan view is provided, a first electrode 4 on the support substrate, an electrolyte film 5 on the first electrode, and a second electrode 6 on the electrolyte film. The first electrode includes a first thin film electrode 4A formed in a manner of covering at least the region, and a first mesh-like electrode 4B connected to the first thin film electrode and provided corresponding to the support portion. The first mesh-like electrode 4B has a film thickness larger than that of the first thin film electrode and has a mesh-like shape in a plan view.

A fuel cell system including a fuel cell, an off-gas reprocessing unit that is provided downstream of the fuel cell and that at least partially removes at least one of steam or carbon dioxide from an off-gas discharged from the fuel cell, a flow passage that is provided downstream of the off-gas reprocessing unit and that allows a reprocessed off-gas discharged from the off-gas reprocessing unit to flow therethrough, and a controlling unit that modulates the reaction constant K.sub.pa of a reaction A with respect to the reprocessed off-gas discharged from the off-gas reprocessing unit, to 1.22 or more.

A fuel cell system including a fuel cell, an off-gas reprocessing unit that is provided downstream of the fuel cell and that at least partially removes at least one of steam or carbon dioxide from an off-gas discharged from the fuel cell, a flow passage that is provided downstream of the off-gas reprocessing unit and that allows a reprocessed off-gas discharged from the off-gas reprocessing unit to flow therethrough, and a controlling unit that modulates the reaction constant K.sub.pa of a reaction A with respect to the reprocessed off-gas discharged from the off-gas reprocessing unit, to 1.22 or more.

Electrochemical systems for distributed energy generation, comprising protonic ceramic fuel cells (PCFCs), are provided. The systems of the present invention allow for operation at lower stack temperatures than current solid oxide fuel cell (SOFC) systems. These systems can achieve various advantages and benefits over SOFC systems, such as higher fuel utilization, improved cell voltage, and air ratio optimization.

Electrochemical systems for distributed energy generation, comprising protonic ceramic fuel cells (PCFCs), are provided. The systems of the present invention allow for operation at lower stack temperatures than current solid oxide fuel cell (SOFC) systems. These systems can achieve various advantages and benefits over SOFC systems, such as higher fuel utilization, improved cell voltage, and air ratio optimization.

A formed substrate assembly includes an air flow form plate, a fuel flow form plate, and an anode. The fuel flow form plate is positioned over the air flow form plate. The fuel flow form plate partially defines a plurality of first channels. The fuel flow form plate also defines a plurality of second channels. The plurality of second channels defines a plurality of apertures, where a portion of the apertures extend from the plurality of second channels to the plurality of first channels. The anode is positioned over the fuel flow form plate. The anode partially defines the plurality of first channels such that the fuel flow form plate and the anode define the plurality of first channels. The portion of the plurality of apertures is configured to channel a flow of fuel from the plurality of second channels to the plurality of first channels.