Fuel cell system and control method for fuel cell system

Patent metadata

Field	Value
Publication number	US-12009556-B2
Application number	US-202217807107-A
Country	US
Kind code	B2
Filing date	Jun 15, 2022
Priority date	Jan 17, 2020
Publication date	Jun 11, 2024
Grant date	Jun 11, 2024

Abstract

The fuel cell system of the present disclosure includes: a fuel cell that includes a membrane electrode assembly including a proton conducting ceramic electrolyte membrane, a cathode disposed on a first surface of the electrolyte membrane, and an anode disposed on a second surface of the electrolyte membrane, the fuel cell generating electric power through an electrochemical reaction using a fuel gas and an oxidant gas; a power source that applies a voltage to the fuel cell; and a controller. In a shutdown process, the controller controls the power source to apply the voltage to the fuel cell such that a terminal voltage of the fuel cell is equal to or higher than an open circuit voltage of the fuel cell.

First claim

What is claimed is:

1. A fuel cell system comprising:
a fuel cell that includes a membrane electrode assembly including a proton conducting ceramic electrolyte membrane, a cathode disposed on a first surface of the electrolyte membrane, and an anode disposed on a second surface of the electrolyte membrane, the fuel cell generating electric power through an electrochemical reaction using a fuel gas and an oxidant gas;
a power source that applies a voltage to the fuel cell;
a temperature detector that detects a temperature of the fuel cell; and
a controller including a processing unit and a memory circuit storing a control program,
wherein, the control program, when executed by the processing unit, causes the controller, in a shutdown process, to control the power source to apply the voltage to the fuel cell such that a terminal voltage of the fuel cell is equal to or higher than an open circuit voltage of the fuel cell,
wherein the electrolyte membrane has hole conductivity, and
wherein the control program, when executed by the processing unit, causes the controller to control the power source in the shutdown process such that the terminal voltage is equal to or higher than the open circuit voltage until the temperature detected by the temperature detector is determined to be equal to or lower than a temperature at which hole conduction in the electrolyte membrane decreases.

2. The fuel cell system according to claim 1 , wherein the control program, when executed by the processing unit, causes the controller to control the power source in the shutdown process such that the terminal voltage is equal to or higher than the open circuit voltage and lower than a voltage at which electrolysis of water starts at the cathode.

3. A fuel cell system comprising:
a fuel cell that includes a membrane electrode assembly including a proton conducting ceramic electrolyte membrane, a cathode disposed on a first surface of the electrolyte membrane, and an anode disposed on a second surface of the electrolyte membrane, the fuel cell generating electric power through an electrochemical reaction using a fuel gas and an oxidant gas;
a power source that applies a voltage to the fuel cell;
a temperature detector that detects a temperature of the fuel cell; and
a controller including a processing unit and a memory circuit storing a control program,
wherein, the control program, when executed by the processing unit, causes the controller, in a shutdown process, to control the power source to apply the voltage to the fuel cell such that a terminal voltage of the fuel cell is equal to or higher than an open circuit voltage of the fuel cell, and
wherein the control program, when executed by the processing unit, causes the controller to control the power source in the shutdown process such that the terminal voltage is equal to or higher than the open circuit voltage until the temperature detected by the temperature detector is determined to be equal to or lower than a temperature at which an oxidation-reduction reaction at the anode slows down.

4. The fuel cell system according to claim 1 , wherein the control program, when executed by the processing unit, causes the controller to control the power source in the shutdown process such that the terminal voltage is equal to or higher than the open circuit voltage until the temperature detected by the temperature detector is determined to be equal to or lower than 500° C.

5. The fuel cell system according to claim 1 , wherein the control program, when executed by the processing unit, causes the controller to control the power source in the shutdown process such that the terminal voltage is equal to or higher than the open circuit voltage until the temperature detected by the temperature detector is determined to be equal to or lower than 400° C.

6. The fuel cell system according to claim 1 , further comprising a voltage detector that detects a voltage of the fuel cell,
wherein the open circuit voltage is the voltage of the fuel cell that is detected by the voltage detector when no electric current is inputted/outputted to/from the fuel cell.

7. The fuel cell system according to claim 1 , wherein the shutdown process is performed in a period from when the temperature of the fuel cell starts decreasing until the temperature of the fuel cell becomes lower than 200° C.

8. The fuel cell system according to claim 1 , further comprising:
a fuel gas feeder that feeds the fuel gas to the anode; and
an oxidant gas feeder that feeds the oxidant gas to the cathode.

9. The fuel cell system according to claim 8 , wherein the control program, when executed by the processing unit, causes the controller to control the fuel gas feeder in the shutdown process such that the amount of the fuel gas fed to the anode is larger than a fuel consumption of the fuel cell.

10. The fuel cell system according to claim 1 , wherein the power source is an electrical power system, a power generator, or a battery.

11. The fuel cell system according to claim 1 , wherein the fuel cell is a solid oxide fuel cell.

12. The fuel cell system according to claim 1 , wherein the electrolyte membrane contains an oxide.

13. A fuel cell system comprising:
a fuel cell that includes a membrane electrode assembly including a proton conducting ceramic electrolyte membrane, a cathode disposed on a first surface of the electrolyte membrane, and an anode disposed on a second surface of the electrolyte membrane, the fuel cell generating electric power through an electrochemical reaction using a fuel gas and an oxidant gas;
a power source that applies a voltage to the fuel cell; and
a controller including a processing unit and a memory circuit storing a control program,
wherein, the control program, when executed by the processing unit, causes the controller, in a shutdown process, to control the power source to apply the voltage to the fuel cell such that a terminal voltage of the fuel cell is equal to or higher than an open circuit voltage of the fuel cell,
wherein the electrolyte membrane contains a compound represented by BaCe 1-x M x O 3-α , BaZr 1-x-y Ce x M y O 3-α , or BaZr 1-x M x O 3-α , where M is a trivalent substituent element, x is 0<x<1, y is 0<y<1, and α is an oxygen deficiency and is 0<α<0.5.

14. A fuel cell system comprising:
a fuel cell that includes a membrane electrode assembly including a proton conducting ceramic electrolyte membrane, a cathode disposed on a first surface of the electrolyte membrane, and an anode disposed on a second surface of the electrolyte membrane, the fuel cell generating electric power through an electrochemical reaction using a fuel gas and an oxidant gas;
a power source that applies a voltage to the fuel cell; and
a controller including a processing unit and a memory circuit storing a control program,
wherein, the control program, when executed by the processing unit, causes the controller, in a shutdown process, to control the power source to apply the voltage to the fuel cell such that a terminal voltage of the fuel cell is equal to or higher than an open circuit voltage of the fuel cell,
wherein the electrolyte membrane contains a compound represented by BaZr 1-x Yb x O 3-α , where x is 0<x<1, and α is an oxygen deficiency and is 0<α<0.5.

15. A method for controlling a fuel cell system including:
a fuel cell that includes a membrane electrode assembly including a proton conducting electrolyte membrane, a cathode disposed on a first surface of the electrolyte membrane, and an anode disposed on a second surface of the electrolyte membrane, the fuel cell generating electric power throu

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Terayama Takeshi
• Kuroha Tomohiro
• Kawada Kyohei

Classifications

• H01M8/1016

  characterised by the electrolyte material (H01M8/12 takes precedence) · CPC title

• H01M8/1004

  characterised by membrane-electrode assemblies [MEA] (H01M8/12 takes precedence) · CPC title

• H01M8/04873

  of the individual fuel cell · CPC title

• H01M8/04089

  of gaseous reactants · CPC title

• H01M8/126

  the electrolyte containing cerium oxide · CPC title