A fuel cell single unit including: a fuel cell element in which an anode layer and a cathode layer are formed so as to sandwich an electrolyte layer; a reducing gas supply path for supplying a gas containing hydrogen to the anode layer; an oxidizing gas supply path for supplying a gas containing oxygen to the cathode layer; and an internal reforming catalyst layer, which has a reforming catalyst for steam-reforming a fuel gas, in at least a part of the reducing gas supply path is provided. An external reformer, which has a reforming catalyst for steam-reforming the fuel gas, is provided upstream of the reducing gas supply path, and the fuel gas partially reformed by the external reformer is supplied to the reducing gas supply path.

A fuel cell single unit including: a fuel cell element in which an anode layer and a cathode layer are formed so as to sandwich an electrolyte layer; a reducing gas supply path for supplying a gas containing hydrogen to the anode layer; an oxidizing gas supply path for supplying a gas containing oxygen to the cathode layer; and an internal reforming catalyst layer, which has a reforming catalyst for steam-reforming a fuel gas, in at least a part of the reducing gas supply path is provided. An external reformer, which has a reforming catalyst for steam-reforming the fuel gas, is provided upstream of the reducing gas supply path, and the fuel gas partially reformed by the external reformer is supplied to the reducing gas supply path.

The invention provides a hybrid power system, which integrates an internal combustion engine with a solid oxide fuel cell (SOFC) stack and provides power for the vehicle through the internal combustion engine at first in the preheating stage of the SOFC stack, thereby solving the problem that an SOFC stack is unable to provide power for the vehicle in the preheating stage. At the same time, the internal combustion engine burns fuel gas, outputs high temperature exhaust gas, heats the heat exchanger with the high temperature exhaust gas, then discharges the exhaust gas from an exhaust turbine and inhales air from the outside of the system. The air first passes through an air preheater, then passes through a heat exchanger and then enters the inside of the SOFC stack, preheats the air preheater through an air pipeline and then is discharged. After multiple cycles, the preheating of the SOFC stack is completed. As the air preheater is connected to the heat exchanger in series to heat the air, the heating speed of the air entering the SOFC stack is raised, the preheating time is shortened and a quick start of the SOFC stack is achieved so that the SOFC stack can be used to achieve the purpose of providing power for the vehicle efficiently.

The invention provides a hybrid power system, which integrates an internal combustion engine with a solid oxide fuel cell (SOFC) stack and provides power for the vehicle through the internal combustion engine at first in the preheating stage of the SOFC stack, thereby solving the problem that an SOFC stack is unable to provide power for the vehicle in the preheating stage. At the same time, the internal combustion engine burns fuel gas, outputs high temperature exhaust gas, heats the heat exchanger with the high temperature exhaust gas, then discharges the exhaust gas from an exhaust turbine and inhales air from the outside of the system. The air first passes through an air preheater, then passes through a heat exchanger and then enters the inside of the SOFC stack, preheats the air preheater through an air pipeline and then is discharged. After multiple cycles, the preheating of the SOFC stack is completed. As the air preheater is connected to the heat exchanger in series to heat the air, the heating speed of the air entering the SOFC stack is raised, the preheating time is shortened and a quick start of the SOFC stack is achieved so that the SOFC stack can be used to achieve the purpose of providing power for the vehicle efficiently.

A solid oxide electrochemical cell includes an oxygen electrode containing a strontium-containing perovskite-type composite oxide represented by Ln.sub.1-xSr.sub.xCo.sub.1-y-zFe.sub.yB.sub.zO.sub.3-δ (Ln is a trivalent lanthanide element, B is a tetravalent element, 0<x<1, 0≤y<1, 0<z<1, and 0<z+y<1, and δ is a value that is determined to satisfy charge neutrality conditions), a solid electrolyte containing zirconium oxide, a hydrogen electrode, and an interlayer containing a rare-earth-doped cerium oxide that is provided between the solid electrolyte and the oxygen electrode.

A cell stack device includes a cell stack, a holding member, and a positive electrode terminal. The cell stack is constructed by stacking a plurality of cells. The holding member holds the cells. The positive electrode terminal functions as a positive electrode when power generated by the cell stack is output to the outside. The potential of the positive electrode terminal is not more than that of the holding member.

Provided is an electrochemical cell, a power generation method using the electrochemical cell, and a manufacturing method of a hydrogen gas using the electrochemical cell that are suitable for the use in a temperature range between 200° C. and 600° C.

A fuel cell 1 (electrochemical cell) includes a proton conductor 5 represented by (Li, H).sub.14−2xZn.sub.1+x(GeO.sub.4).sub.4 where a portion of lithium ions of Li.sub.14−2xZn.sub.1+x(GeO.sub.4).sub.4 where x is a number equal to or more than 0 is substituted with protons, the proton conductor having electric conductivity of 0.01 S/cm or more at 300° C., an anode 6 provided on one side of the proton conductor, a cathode 7 provided on another side of the proton conductor, a first separator 9 provided on an anode side of the proton conductor to define an anode chamber 8, and a second separator 12 provided on a cathode side of the proton conductor to define a cathode chamber 11.

Provided is an electrochemical cell, a power generation method using the electrochemical cell, and a manufacturing method of a hydrogen gas using the electrochemical cell that are suitable for the use in a temperature range between 200° C. and 600° C.

A fuel cell 1 (electrochemical cell) includes a proton conductor 5 represented by (Li, H).sub.14−2xZn.sub.1+x(GeO.sub.4).sub.4 where a portion of lithium ions of Li.sub.14−2xZn.sub.1+x(GeO.sub.4).sub.4 where x is a number equal to or more than 0 is substituted with protons, the proton conductor having electric conductivity of 0.01 S/cm or more at 300° C., an anode 6 provided on one side of the proton conductor, a cathode 7 provided on another side of the proton conductor, a first separator 9 provided on an anode side of the proton conductor to define an anode chamber 8, and a second separator 12 provided on a cathode side of the proton conductor to define a cathode chamber 11.

A cell includes an air electrode layer, a fuel electrode layer, and a solid electrolyte layer. The fuel electrode layer contains a first rare earth element and a second rare earth element different from the first rare earth element. The solid electrolyte layer is located between the air electrode layer and the fuel electrode layer, and contains the second rare earth element. The fuel electrode layer has a first site and a second site. The second site is located between the first site and the solid electrolyte layer, and contains at least the second rare earth element.

A cell includes an air electrode layer, a fuel electrode layer, and a solid electrolyte layer. The fuel electrode layer contains a first rare earth element and a second rare earth element different from the first rare earth element. The solid electrolyte layer is located between the air electrode layer and the fuel electrode layer, and contains the second rare earth element. The fuel electrode layer has a first site and a second site. The second site is located between the first site and the solid electrolyte layer, and contains at least the second rare earth element.