JP2005306695A - Oxygen pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make long term-stable operation of an oxygen pump possible by inexpensively constituting electrical junctures and assuring good electric conductivity and stable joinability. <P>SOLUTION: The oxygen pump comprises an oxygen pump element 12 formed with electrode films 11 on both sides of an oxygen ion conductive substrate 10, metallic members 13 electrically connected to the outer peripheries of the electrode films 11, insulating materials 14 electrically insulating the metallic members 13 and lead members 15 of metallic hollow tubes having a flange shape connected to the metallic members 13. Since the joint having the long term-stable conductivity is possible by the flange form, the prolonging of the oxygen pump is made possible. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an oxygen pump that moves oxygen ions electrochemically.

  Conventionally, this type of oxygen pump is an electrochemical device in which an electrode is provided on a solid electrolyte substrate, and a conductive separator having a projection has a function of isolating oxygen and air, while the projection is electrically connected to the electrode. It was configured to allow connection. In addition, there is a solid electrolyte oxygen pump in which platinum electrodes are provided on both surfaces of a solid electrolyte cylindrical body, and a platinum net is provided on the platinum electrode (for example, see Patent Document 1).

  FIG. 3 shows a conventional oxygen pump described in Patent Document 1. As shown in FIG. As shown in FIG. 3, a cathode layer 2 and an anode layer 3 having a three-layer electrode structure are formed on the surface of the ceramic substrate 1, and protrusions 6 (6 a and 6 b) are provided on the separators 4 and 5. It has become.

  FIG. 4 shows a conventional oxygen pump described in Patent Document 2. As shown in FIG. 4, the solid electrolyte cylindrical body 7 is composed of a platinum electrode 8 and a platinum net 9.

Further, Patent Document 3 also discloses an oxygen pump.
Special table 2003-288904 gazette JP-A-9-127051 JP 2000-86204 A

  However, in the conventional configuration, the metal electrode increases the conductivity, reduces the contact resistance with the separator and reduces the number of electrical contacts, but the selection of the separator material is limited due to the high operating temperature In some cases, when oxidation in a high oxygen atmosphere or thermal strain due to high temperature occurs, there is a problem that the conductivity decreases due to poor contact.

  In addition, in the electrical connection using the platinum net, a practical device for maintaining the contact resistance constant is necessary for practical use, and there is a problem that it is expensive.

  The present invention solves the above-described conventional problems, and an object thereof is to provide an oxygen pump having a lead portion that is stable and inexpensive in electrical connection.

  In order to solve the conventional problems, an oxygen pump according to the present invention includes an oxygen pump element in which electrode films are formed on both surfaces of an oxygen ion conductive substrate, and a metal member that is electrically connected to the outer periphery of the electrode film. And an insulating material that electrically insulates the metal member, and a lead member of a metal hollow tube having a flange shape connected to the metal member.

  As a result, a bonding surface between the lead portion and the metal member is secured, and it has low cost, good conductivity, and stable bonding properties.

  Since the oxygen pump of the present invention can be electrically connected for a long time, a long-life oxygen pump can be provided.

  The first invention electrically insulates the metal member from an oxygen pump element having electrode films formed on both surfaces of an oxygen ion conductive substrate, a metal member electrically connected to the outer periphery of the electrode film, and By comprising the insulating material and the lead member of the metal hollow tube having a flange shape connected to the metal member, the metal base material and the lead member have a wide conductive area secured through the flange structure, and can be used for a long time. Good electrical connection is possible.

  In the second invention, in particular, a stable connection having conductivity can be achieved by connecting the metal member and the lead member with a conductive binder.

  In the third invention, in particular, the metal member and the lead member are connected by welding, and a stable connection having conductivity is possible.

  In the fourth aspect of the invention, in particular, since the lead member and the metal member are the same component, a connection strong against mechanical deformation such as thermal shock becomes possible.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a schematic cross-sectional view of an oxygen pump according to the first embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of the lead portion according to the first embodiment of the present invention.

In FIG. 1, an oxygen ion conductive substrate 10 is made of a sintered lanthanum gallate (La _0.8 Sr _0.2 Ga _0.8 Mg _0.2 O ₃ ) sintered body having an arbitrary thickness (for example, about 200 μm). ), The electrode film 11 is formed on both surfaces thereof, and the oxygen pump element 12 is formed.

  A metal member 13 is electrically joined to the outer periphery of both electrode films 11, and an insulating material 14 that is electrically insulated is disposed between the metal members 13. Further, a metal hollow tube lead member 15 having a flange shape is electrically joined to the metal member 13 to constitute an oxygen pump.

  The oxygen ion conductive substrate 10 is not limited to lanthanum gallate, and may be yttrium-doped zirconia (YSZ), samarium-doped ceria (SDC), or the like.

A perovskite complex oxide having conductivity was used for the electrode film. For example, a paste obtained by mixing Sm _0.5 Sr _0.5 CoO ₃ with a cellulosic vehicle that is an organic solvent is formed into a porous film having a film thickness of 10 to 20 μm by forming a printed film by screen printing, drying, and firing. An electrode film was formed.

  Further, the electrode film 11 may have a two-layer structure in which a porous film made of metal such as gold or platinum having high conductivity is formed on the surface of a porous electrode film using a perovskite complex oxide. . The forming method may be printing as described above. In particular, when the metal member 13 is joined, an electrode film in which a metal porous film is formed is preferable.

  The metal member 13 is joined to the electrode film 11 by a conductive binder mainly composed of metal such as gold or platinum having high conductivity. Suitable materials are heat-resistant metals such as stainless steel, nickel, iron, and chromium alloys. The metal member 13 is preferably a thin plate having a thickness of about several tens of micrometers so that the mechanical influence on the oxygen ion conductive substrate 10 can be reduced.

  The insulating material 14 electrically insulates the metal member 13 joined to both electrode films 11 and is made of an insulating material such as mica. The thickness is not limited, but is preferably equivalent to that of the oxygen ion conductive substrate 10.

  The lead portion 15 of the metal hollow tube has a flange shape 15a as shown in FIG. 2, and is joined to the metal member 13 by a conductive binder or welding. Suitable materials are heat-resistant metals such as stainless steel, nickel, iron, and chromium alloys. In an environment where the thermal expansion and contraction is severe, the thermal expansion coefficient can be matched by reducing the thermal influence by using the same material for the metal member 13 and the lead portion 15. The plate thickness of the metal hollow tube of the lead portion is not limited, but may be the same level as the metal member. Since the lead part of the metal hollow tube does not use a noble metal such as platinum or gold as in the prior art, it can be made inexpensive.

  About the oxygen pump comprised as mentioned above, the operation | movement and an effect | action are demonstrated below. The metal member 13 and the lead portion 15 have a remarkably wide electrical joint surface compared to the conventional case due to the flange shape. Therefore, since the electrical resistance is reduced, high conductivity is ensured, and the junction area is wide, so that stable conductivity can be secured over a long period of time.

  As described above, in the present embodiment, the oxygen pump element 12 in which the electrode film 11 is formed on both surfaces of the oxygen ion conductive substrate 10, and the metal member 13 electrically connected to the outer periphery of the electrode film 11. A long-term stable operation of the oxygen pump is constituted by an insulating material 14 that electrically insulates the metal member 13 and a lead member 15 of a metal hollow tube having a flange shape connected to the metal member 13. Is possible.

  As described above, since the oxygen pump according to the present invention can be stably operated for a long period of time, it can be applied to a wide range of uses such as an air purifier, an air conditioner, a health promoting device, and a health promoting device using oxygen.

Schematic sectional view of an oxygen pump in the first embodiment of the present invention Schematic sectional view of the lead portion of the oxygen pump in the first embodiment of the present invention The figure which shows the structure of the conventional oxygen pump shown by patent document 1 The figure which shows the structure of the conventional oxygen pump shown by patent document 2

Explanation of symbols

10 Oxygen ion conductive substrate 11 Electrode film 12 Oxygen pump element 13 Metal member 14 Insulating material 15 Lead portion

Claims (4)

An oxygen pump element having electrode films formed on both surfaces of an oxygen ion conductive substrate; a metal member electrically connected to an outer periphery of the electrode film; an insulating material electrically insulating the metal member; and the metal An oxygen pump having a metal hollow tube lead member having a flange shape connected to the member. The oxygen pump according to claim 1, wherein the metal member and the lead member are connected by a conductive binder. The oxygen pump according to claim 1 or 2, wherein the metal member and the lead member are connected by welding. The oxygen pump according to any one of claims 1 to 3, wherein the lead member and the metal member are the same component.

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