A method and apparatus for operating an intermediate-temperature solid-oxide fuel cell stack (10) with a mixed ionic/electronic conducting electrolyte in order to increase its efficiency. The required power output of the solid-oxide fuel cell stack (10) is determined and one or more operating conditions of the solid fuel cell stack (10) are controlled dependent upon the determined required power output. The operating conditions that are controlled may be at least one or the temperature of the fuel cell stack and the dilution of fuel delivered to the fuel cell stack.

A method and apparatus for operating an intermediate-temperature solid-oxide fuel cell stack (10) with a mixed ionic/electronic conducting electrolyte in order to increase its efficiency. The required power output of the solid-oxide fuel cell stack (10) is determined and one or more operating conditions of the solid fuel cell stack (10) are controlled dependent upon the determined required power output. The operating conditions that are controlled may be at least one or the temperature of the fuel cell stack and the dilution of fuel delivered to the fuel cell stack.

A fuel cell stack having a structure in which a plurality of single fuel cells C(1) and a plurality of interconnectors (5) are disposed alternately between a pair of end members and such that a junction member J composed of an elastic member (20) and an electrically conductive member (21) is disposed in a space (3a) formed between a first end member (3) and a first interconnector (5(1)). A portion of the electrically conductive member (21) is disposed between the first end member (3) and the elastic member (20), and another portion of the electrically conductive member (21) is disposed between the first interconnector (5(1)) and the elastic member (20); and the first end member (3) and the first interconnector (5(1)) are electrically connected through the electrically conductive member (21).

A fuel cell stack having a structure in which a plurality of single fuel cells C(1) and a plurality of interconnectors (5) are disposed alternately between a pair of end members and such that a junction member J composed of an elastic member (20) and an electrically conductive member (21) is disposed in a space (3a) formed between a first end member (3) and a first interconnector (5(1)). A portion of the electrically conductive member (21) is disposed between the first end member (3) and the elastic member (20), and another portion of the electrically conductive member (21) is disposed between the first interconnector (5(1)) and the elastic member (20); and the first end member (3) and the first interconnector (5(1)) are electrically connected through the electrically conductive member (21).

In various embodiments, a solid oxide fuel cell is fabricated in part by disposing a functional layer between the cathode and the solid electrolyte.

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.

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.

A method of manufacturing a solid oxide electrolyzer cell (SOEC) includes removing a binder from the SOEC using microwave radiation while the SOEC is disposed in a first zone of a furnace, and sintering the SOEC while the SOEC is disposed in a second zone of the furnace.

A membrane electrode assembly according to the present disclosure includes an electrolyte membrane containing a proton conductive oxide and an electrode containing a lanthanum strontium cobalt iron composite oxide located on the electrolyte membrane, wherein, in the electrode, the ratio of the number of moles of cobalt to the sum of the number of moles of cobalt and the number of moles of iron is 0.35 or more and 0.6 or less.

A membrane electrode assembly according to the present disclosure includes an electrode, an electrolyte layer bonded to the electrode and containing an electrolyte having proton conductivity, a metal frame, and a bonding layer disposed between a peripheral part of the electrolyte layer and the metal frame and held in contact with each of the electrolyte layer and the metal frame, wherein the bonding layer has a thickness of greater than or equal to 0.50 mm.