Anode layer activation method for solid oxide fuel cell, and solid oxide fuel cell system

Patent metadata

Field	Value
Publication number	US-2020343561-A1
Application number	US-201816960942-A
Country	US
Kind code	A1
Filing date	Feb 9, 2018
Priority date	Feb 9, 2018
Publication date	Oct 29, 2020
Grant date	—

Abstract

A solid oxide fuel cell includes a metal support cell, in which an anode layer containing nickel, an electrolyte layer and a cathode layer are stacked on a metal support portion. In the method for activating the anode layer in the solid oxide fuel cell, first, an oxygen-containing gas is introduced into the anode layer to oxidize the nickel. Next, a hydrogen-containing gas HG is introduced into the anode layer to reduce the nickel oxide formed by oxidizing the nickel, and to increase conduction paths of the nickel that electrically connect the electrolyte layer to the metal support part in the anode layer.

First claim

1 . An anode layer activation method in a solid oxide fuel cell having a metal support cell, in which an anode layer containing nickel, an electrolyte layer and a cathode layer are stacked on a metal support part, the anode layer activation method comprising:
introducing an oxygen-containing gas into the anode layer to oxidize the nickel, and introducing a hydrogen-containing gas into the anode layer to reduce the nickel that was oxidized and to thereby increase conduction paths formed by reduction of the nickel that electrically connect the electrolyte layer to the metal support part in the anode layer.

2 . The anode layer activation method according to claim 1 , wherein
introduction of the oxygen-containing gas and the hydrogen-containing gas is executed at a temperature of 400° C. to 850° C.

3 . The anode layer activation method according to claim 1 , wherein
introduction of the oxygen-containing gas and the hydrogen-containing gas is executed at a temperature that is higher than an operating temperature of the solid oxide fuel cell.

4 . The anode layer activation method according to claim 1 , wherein
the introduction temperature of the hydrogen-containing gas is lower than the introduction temperature of the oxygen-containing gas.

5 . The anode layer activation method according to claim 1 , wherein
the solid oxide fuel cell includes a constituent member containing a binder, and burning and oxidizing the binder of the constituent member when oxidizing the nickel.

6 . The anode layer activation method according to claim 1 , wherein
the oxygen-containing gas is air.

7 . The anode layer activation method according to claim 1 , wherein
the oxygen-containing gas is a gas containing oxygen obtained by a water dissociation reaction in a gas containing water.

8 . The anode layer activation method according to claim 1 , wherein
introduction times of the oxygen-containing gas and the hydrogen-containing gas are each 2 hours or more.

9 . The anode layer activation method according to claim 1 , wherein
the oxygen-containing gas to be introduced is scavenged from the anode layer before introducing the hydrogen-containing gas.

10 . The anode layer activation method according to claim 9 , wherein
the oxygen-containing gas to be introduced is scavenged from the anode layer using an inert gas.

11 . The anode layer activation method according to claim 1 , wherein
respective potentials of the anode layer at a time of oxidation and a time of reduction are natural potentials.

12 . The anode layer activation method according to claim 1 , wherein
oxidation and reduction of the anode layer are only carried out once per one switching to introduction of the hydrogen-containing gas after introduction of the oxygen-containing gas.

13 . A solid oxide fuel cell system comprising:
a solid oxide fuel cell having a metal support cell, in which an anode layer containing nickel, an electrolyte layer and a cathode layer are stacked on a metal support part, a fuel introduction unit that introduces a hydrogen-containing gas into the anode layer, an oxidation processing unit that introduces an oxygen-containing gas into the anode layer, and a control unit that controls operations of the fuel introduction unit and the oxidation processing unit, when activating the anode layer, the control unit being configured to operate the oxidation processing unit to introduce the oxygen-containing gas into the anode layer to oxidize the nickel, and being configured to operate the fuel introduction unit to introduce the hydrogen-containing gas into the anode layer to reduce the nickel that was oxidized to thereby increase conduction paths formed by reduction of the nickel that electrically connect the electrolyte layer to the metal support part in the anode layer.

14 . A solid oxide fuel cell comprising:
a metal support cell having an anode layer containing nickel, an electrolyte layer and a cathode layer are stacked on a metal support part, the anode layer having three-phase boundaries defined the nickel, electrolytes and pores, the anode layer including conduction paths of the nickel that connect the electrolyte layer to the metal support part, and the conduction paths of the nickel being thinner than conduction paths formed by oxidization of the nickel.

15 . The solid oxide fuel cell according to claim 14 , wherein
the conduction paths of the nickel in the anode layer are formed by oxidizing and reducing the nickel.

16 . The solid oxide fuel cell according to claim 15 , wherein
the conduction paths formed by oxidizing the nickel are formed by introducing an oxygen-containing gas into the anode layer to connect the nickel.

17 . The solid oxide fuel cell according to claim 15 , wherein
the conduction paths formed by the nickel are formed by introducing a hydrogen-containing gas into the anode layer to reduce the conduction paths formed by the oxidization of the nickel.

18 . The solid oxide fuel cell according to claim 16 , wherein
the conduction paths formed by the nickel are formed by introducing a hydrogen-containing gas into the anode layer to reduce the conduction paths formed by the oxidization of the nickel.

Assignees

• Nissan Motor

Inventors

• Fukuyama Yosuke
• Kawabuchi Mari
• Sato Kazuyuki

Classifications

• Y02T90/40

  Application of hydrogen technology to transportation, e.g. using fuel cells · CPC title

• H01M8/04231

  Purging of the reactants · CPC title

• H01M2250/20

  Fuel cells in motive systems, e.g. vehicle, ship, plane · CPC title

• H01M2008/1293

  Fuel cells with solid oxide electrolytes · CPC title

• H01M4/905 Primary

  specially used in fuel cell operating at high temperature, e.g. SOFC · CPC title