An assembly includes an SOEC/SOFC-type solid oxide stack, a clamping system for clamping the stack, including at least two clamping rods that can be used to assemble upper and lower clamping plates, and a coupling system for high-temperature fluid-tight coupling of the stack to a heating system for supplying and discharging gas. The coupling system includes a collector with collection ducts for supplying and discharging gas, each provided with a collecting port positioned facing a corresponding communication port of at least one of the upper and lower clamping plates, and seals each placed between a collecting port and a corresponding communication port.

A module assembly is provided including a fuel cell stack assembly, a heat exchanger, and a housing enclosing the fuel cell stack assembly and the heat exchanger. The heat exchanger is configured to receive process gas from an external source and output said process gas to the fuel cell stack assembly, and configured to receive process gas from the fuel cell stack assembly and output said process gas. A fuel cell power plant is provided including a module assembly with a first end, a racking structure configured to hold the module assembly, balance of plant equipment, and ducting configured to provide fluid communication between the balance of plant equipment and the first end of the module assembly. The module assembly and the racking structure are configured such that the module assembly may be removed from the racking structure in a direction away from the first end of the module assembly.

A module assembly is provided including a fuel cell stack assembly, a heat exchanger, and a housing enclosing the fuel cell stack assembly and the heat exchanger. The heat exchanger is configured to receive process gas from an external source and output said process gas to the fuel cell stack assembly, and configured to receive process gas from the fuel cell stack assembly and output said process gas. A fuel cell power plant is provided including a module assembly with a first end, a racking structure configured to hold the module assembly, balance of plant equipment, and ducting configured to provide fluid communication between the balance of plant equipment and the first end of the module assembly. The module assembly and the racking structure are configured such that the module assembly may be removed from the racking structure in a direction away from the first end of the module assembly.

A fuel cell assembly is mounted on a vehicle via a mounting portion. The fuel cell assembly includes a first fuel cell unit, a first frame portion on which the first fuel cell unit is mounted and fixed, a second fuel cell unit, a second frame portion on which the second fuel cell unit is mounted and fixed, and a connecting portion that connects the first frame portion and the second frame portion such that the second fuel cell unit is located above the first fuel cell unit.

A fuel cell assembly is mounted on a vehicle via a mounting portion. The fuel cell assembly includes a first fuel cell unit, a first frame portion on which the first fuel cell unit is mounted and fixed, a second fuel cell unit, a second frame portion on which the second fuel cell unit is mounted and fixed, and a connecting portion that connects the first frame portion and the second frame portion such that the second fuel cell unit is located above the first fuel cell unit.

A fuel cell system column includes a first terminal plate connected to a first electrical output of the column, a second terminal plate connected to a second electrical output of the column, at least one first fuel cell stack located in a middle portion of the column between the first terminal plate and the second terminal plate, and at least one electrical connection which is electrically connected to the middle portion of the column and which is configured to provide a more uniform fuel utilization across the first column.

A cell includes an element portion that includes: a fuel electrode; a solid electrolyte layer; an air electrode; and an intermediate layer located between the solid electrolyte layer and the air electrode. The solid electrolyte layer or the intermediate layer includes: a first site; and a second site that is located closer to the air electrode or closer to a center part of the element portion than the first site and that has a smaller porosity or a lower density than the first site.

A cell includes an element portion that includes: a fuel electrode; a solid electrolyte layer; an air electrode; and an intermediate layer located between the solid electrolyte layer and the air electrode. The solid electrolyte layer or the intermediate layer includes: a first site; and a second site that is located closer to the air electrode or closer to a center part of the element portion than the first site and that has a smaller porosity or a lower density than the first site.

A cell includes an element portion and a support substrate. The support substrate includes a gas-flow passage through which the reactive gas flows in a first direction, and supports the element portion. The element portion includes a first portion having a first length in a second direction intersecting the first direction, and a second portion located on a downstream side in the gas-flow passage relative to the first portion, the second portion having a second length in the second direction different from the first length in the second direction.

A cell includes an element portion and a support substrate. The support substrate includes a gas-flow passage through which the reactive gas flows in a first direction, and supports the element portion. The element portion includes a first portion having a first length in a second direction intersecting the first direction, and a second portion located on a downstream side in the gas-flow passage relative to the first portion, the second portion having a second length in the second direction different from the first length in the second direction.