To reduce thermal stress and improve bonding in a high temperature monolithic solid oxide fuel cell (SOFC), intermediate layers are provided between the SOFC's electrodes and electrolyte which are of different compositions. The intermediate layers are comprised of a blend of some of the materials used in the electrode and electrolyte compositions. Particle size is controlled to reduce problems involving differential shrinkage rates of the various layers when the entire structure is fired at a single temperature, while pore formers are provided in the electrolyte layers to be removed during firing for the formation of desired pores in the electrode layers. Each layer includes a binder in the form of a thermosetting acrylic which during initial processing is cured to provide a self-supporting structure with the ceramic components in the green state. A self-supporting corrugated structure is thus formed prior to firing, which the organic components of the binder and plasticizer removed during firing to provide a high strength, high temperature resistant ceramic structure of low weight and density.
A solid oxide fuel cell comprising a separator plate made of a material having stability against oxidation and reduction and electronic conductivity, an air electrode spacer made of a material having oxidation resistance and electronic conductivity, a flat plate-shaped solid oxide fuel cell element, a fuel electrode spacer, and another separator plate made of a material having oxidation resistance, reduction resistance and electronic conductivity, and another separator plate. The separator plate, the air electrode spacer, the solid oxide fuel cell element, the fuel electrode spacer and another separator plate are successively laminated in this order. The solid oxide fuel cell element including an ion-conductive ceramic plate, and an air electrode and a fuel electrode formed on opposite surfaces of said ceramic plate, respectively. An oxidizing gas chamber is defined by the separator plate, the air electrode spacer and the element, and a fuel gas chamber is defined by the element, the fuel electrode spacer, and another separator plate. A process for producing such a solid oxide fuel cell comprises the steps of forming the ion-conductive ceramic plate by sintering, forming the air electrode and a fuel electrode on opposite surfaces of the ceramic plate, respectively, and successively laminating the separator plate, the air electrode spacer, the solid oxide fuel cell element, the fuel electrode spacer and another separator plate in this order.
A solid oxide fuel cell stack is disclosed. The solid oxide fuel cell stack comprises an electrochemical cell having an electrolyte disposed between and in ionic communication with a first electrode and a second electrode. The solid oxide fuel cell stack also comprises at least one interconnect disposed in fluid and thermal communication with at least a portion of the electrochemical cell, the interconnect comprising an electrical supply connector.
A fuel cell which converts chemical energy from a fuel/oxidant gas mixture to electricity for power usage or gas-sensing applications is disclosed. The fuel cell has a solid electrolyte wall with electrodes on each side. Each side of the wall is surrounded by a partition which forms a first and second chamber whereon the fuel/oxidant gas mixture is allowed to diffuse. Means are provided to initiate a voltage drop between the electrodes which initiates the chemical reaction. Electricity is collected from the electrodes. In an alternate design the fuel cell has a first and second electrolyte wall with electrodes on each side of the walls. A partition wall separates the first and second walls thereby forming a first chamber with the first wall and the partition wall and a second chamber with the partition wall and the second wall. Gas-flow limiting means exist between the fuel/oxidant gas mixture and the first chamber and the first chamber and the second chamber. The chemical reaction starts spontaneously and electricity is collected and stored from each set of electrodes.
A solid oxide fuel cell includes a plurality of flat plate-like laminates spaced substantially in parallel with one another. One surface of each of the laminates is covered with a flat air electrode film, while the other surface is covered with a flat fuel electrode film. The fuel cell further includes a plurality of oxidizing gas flow passages each arranged between the adjacent laminates and facing the flat air electrode film, a plurality of fuel gas flow passages each arranged between the adjacent flat laminates and facing the flat fuel electrode films and at least air electrode films, solid electrolyte films and fuel electrode films interposed between the oxidizing and fuel gas flow passages. Oxidizing gas supply pipes are each extended from an opening at one end of each of the oxidizing gas flow passages into the gas flow passage, and closure members each close the other end of the oxidizing gas flow passage. Fuel gas supply pipes are each extending from an opening at one end of each of the fuel gas flow passages into the gas flow passage, and closure members each close the other end of the fuel gas flow passage.
An electrochemical cell including at least one dense solid electrolyte body, at least two dense interconnectors for collecting current flowing through the cell, cathodes and anodes, wherein the at least one dense solid electrolyte body and at least two dense interconnectors constitute a structural body, a plurality of first gas flow channels and a plurality of second gas flow channels both extend in a given direction, and are each defined and surrounded by a part of the at least one solid electrolyte body and a part of the at least two interconnectors, the anodes are formed on respective walls defined by a part of at least one solid electrolyte body and a part of at least two interconnectors and constituting the respective first gas flow channels, the cathodes are formed on respective walls defined by a part of at least one solid electrolyte body and a part of at least two interconnectors and constituting the respective second gas flow channels, every anode is opposed to an adjacent cathode or adjacent cathodes via a solid electrolyte body, and every cathode is opposed to an adjacent anode or adjacent anodes via a solid electrolyte body.
