JPS5958759A - Air electrode and its manufacture - Google Patents

Abstract

PURPOSE:To prevent elements detrimental to electrode reaction, such as carbon dioxide and steam, from penetrating a battery by providing an extremely thin complex film, without pin holes and having a selective permeability to oxygen gas, over the gas-side surface of an electrode body in such a manner as to be unified with the electrode body. CONSTITUTION:An air electrode is made by unifying an electrode body, a thin macromolecular film which is formed through application of plasma polymerization over the gas-side surface of the electrode body eithyer directly or with a porous film having minute holes of below 0.1mum diameter interposed, and a thin metal-oxide film formed on the above thin macromolecular film in that order. As an organic compound used to form the thin macromolecular film, the following members can be listed: fluorinated organic compounds such as pentafluorostyrene and mixture of these compounds; saturated hydrocarbons of C1-C12, unsaturated hydrocarbons of C1-C12, alkyl benzene compounds of C1- C14, hydrocarbon-system compounds such as styrene and alpha-methyl styrene and mixture of these compounds. It is preferred that the thickness of the thin macromolecular film is in the range of 0.01-1.0mum.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an air electrode for hydrogen/oxygen fuel cells, metal/air batteries, and oxygen sensors, and a method for manufacturing the same. This invention relates to an air electrode that is capable of load discharge over 1 m and has excellent storage performance, and a method for manufacturing the same.

[Technical contradiction of the invention and its problems]

Conventionally, gas diffusion electrodes have been used in air metal batteries such as various fuel cells, air metal batteries, and air electrodes such as galvanic oxygen sensors. Initially, a prototype porous electrode with a uniform pore size distribution was used as this gas diffusion electrode, but recently it has been developed to have an electrochemical reduction ability for oxygen gas (ionizes the I!2 element). Two-layer electrodes are often used, consisting of a porous electrode body that also functions as a current collector, and a thin film-like water-repellent layer that is integrally attached to the gas side surface of the electrode body. .

In this case, the electrode body is mainly made of conductive powder such as activated carbon powder supported with nickel-tungstic acid, paranoum and cobalt-coated tungsten carbide, which has low oxygen gas reduction overpotential, nickel, nickel, platinum, palladium, etc. After adding a binder such as polytetrafluoroethylene to the powder, it is made into a porous metal body and a porous carbon body.

Those integrated with carbon fiber non-woven fabric are used.

The water-repellent layer attached to the gas side surface of the electrode body is mainly polytetrafluoroethylene.

BoIJ A thin film composed of a fluororesin such as a tetrafluoroethylene-hexafluoropropylene copolymer, a polyethylene-tetrafluoroethylene copolymer, or a resin such as polypropylene, with a particle size of, for example, 0.2 to 4
A sintered body of these resin powders with a diameter of 0 μm; A paper-like thing made by heat-treating the fibers of these resins to make them into a non-woven fabric; Also a fiber cloth-like thing: A part of these resin powders replaced with fluorinated graphite. Film-like products made by rolling these fine powders together with pore-forming agents, lubricating oil, etc. and then heat-treating them, and film-like products that are not heat-treated after roll-pressing; It is a thin film of sex.

However, in the air electrode of the conventional structure described above,
The water-repellent layer attached to the gas-side surface of the electrode body is impermeable to the electrolyte, but not to air or water vapor in the air.

Therefore, for example, water vapor in the air may pass through the water-repellent layer and enter the electrode body, diluting the electrolyte, or conversely, water in the electrolyte may evaporate from the water-repellent layer as water vapor, causing the electrolyte to dissolve. may be concentrated. As a result, the concentration of the electrolyte fluctuates, resulting in a situation where stable discharge cannot be maintained for a long time.

When carbon dioxide gas in the air passes through the water-repellent layer, enters the electrode body, and is adsorbed on the active layer, the electrochemical reduction ability for oxygen gas at that location decreases, and heavy load discharge is inhibited. In addition, when the electrolyte is an alkaline electrolyte, phenomena such as deterioration of the electrolyte, decrease in concentration, or passivation of the zinc cathode when the cathode is zinc are caused. Furthermore, in the active layer (the porous part of the electrode body), carbonate is generated to block the pores and reduce the area where electrochemical reduction takes place, thereby inhibiting heavy load discharge.

This causes a situation in which the performance of the battery deteriorates from the design standard when the manufactured battery is stored or used for a long period of time.

For this reason, batteries have a structure in which a layer of a moisture absorbent such as calcium chloride or a carbon dioxide gas absorbent such as alkaline earth metal hydroxide is further provided on the gas side (air side) of the water-draining layer of the air electrode. is proposed.

Although this can prevent inconvenient situations such as those that occurred to some extent, after a certain period of time, these absorbents reach a saturated state and lose their absorption capacity, and the effect disappears, so there is no essential effect. A solution like that won't work.

[Purpose of the invention]

The present invention eliminates the above-mentioned drawbacks of the conventional H structure, and prevents water vapor or carbon dioxide gas from entering the electrode body. Therefore, heavy load discharge over a long IK is possible, and storage performance is not affected. The overall purpose is to provide a thin air electrode and its manufacturing method.

[Summary of the invention]

The air electrode of the present invention has a porous electrode body that has an electrochemical reducing ability for oxygen gas and also has a current collector function; Through a porous membrane with micropores of .1 μm or less,
It is characterized by consisting of a polymer thin film 7 formed by integrally laminating by a plasma polymerization method; and a gold handle oxide thin B4 formed by integrally laminating on the polymer thin film. The first manufacturing method is to use a plasma polymerization method to form a thin polymer film on the gas-side surface of a porous electrode body that has an electrochemical reduction ability for flI gas and also has a current collector function. The second method is to form a thin layer of metal oxide on the thin polymer film.
One of the porous membranes having micropores with a pore diameter of 0 to 1 μm or less is formed by forming a polymer thin film using a plasma polymerization method, and further forming a metal oxide N layer on the polymer thin film, Then, the other side of the porous cuff has an iF electrochemical reduction ability for oxygen gas, and the other side of the porous cuff is
12 is characterized in that it is pressure-bonded and integrated with the gas-side surface of the porous electrode main body.

The electrode body used in the air cylinder electrode of the present invention is an electrically conductive porous body that has an active ability to electrochemically reduce oxygen gas (to ionize all oxygen gas). in particular,
In addition to the above-mentioned items, there are silver filters, Raney nickel, sintered bodies of silver or i, j' nickel, various foam metals, compressed bodies of nickel-plated fine stainless steel wire, and gold +/f lasoum, Examples include a metal porous negative body plated with silver or the like. At this time, the reduction product ions of oxygen gas generated by the electrode reaction proceeding within the pores of the electrode body are quickly removed from the pores (reaction region), for example, at a rate of 5°m A/ad.
In order to smoothly continue the heavy load discharge described above, it is preferable that the pore diameters of the pores in the electrode body are distributed in a range of about 1 to 10 μm.

The air electrode of the present invention is as described above! A thin polymer film formed on the gas side surface of the pole body by applying a plasma polymerization method, either directly or via a porous group having micropores with a pore diameter of 0.1 μm or less, and a thin polymer film formed on the thin polymer film. It has a structure in which a thin film of metal oxide is integrally attached in this order.

Here, the polymer thin film according to the present invention is a thin film formed by plasma polymerizing various organic compounds Vl, and all of them are free of pinholes and have excellent permselectivity for oxygen gas. be.

# Examples of organic compounds used for forming the thin film include fluorinated organic compounds such as penztrifluoride, m-chloropencitrifluoride, hexafluorobenzene, pentafluorobenzene, and interfluorostyrene, and mixtures thereof; saturated carbonization of C1 to C12; Hydrogen compound, CI-C1
2 unsaturated hydrocarbon compounds, 01-C14 alkylbenzene compounds, carbonized leaf-based compounds such as styrene and α-methylstyrene, and mixtures thereof, etc.'f! :=h
Among these, the above-mentioned fluorinated organic compounds are preferable because the thin film formed by plasma polymerizing their single molecules is excellent in preventing intrusion of carbon dioxide and water vapor. .

The thickness of the polymer thin film according to the present invention is practically 0.01~
It is preferable that the thickness is in the range of 1.0 μm, and the thickness is in the range of 0.0 μm.
If it is less than 0.0111 m, the formed thin polymer film becomes island-like and cannot uniformly fracture the surface of the electrode body, reducing the effect of preventing the intrusion of carbon dioxide gas or water vapor. Furthermore, the mechanical strength of the entire l-1# film also decreases. On the other hand, if the thickness exceeds 1.0 μm, there will be a shortage of oxygen gas needles supplied to the electrode body, and the discharge characteristics of the electrode will deteriorate (heavy load discharge becomes difficult).

-Although the above-mentioned thin film may be formed as a single layer, it is also possible to form a polymer thin film made of another type of specific compound on this layer.

Next, the metal oxide thin film integrally formed on the polymer thin film is a water-containing or water-friendly gold R oxide H film, a metal oxide thin film having oxygen adsorption ability, Or
It is any thin film of metal oxide with a rutile crystal structure.

Here, water-containing or water-friendly metal oxides refer to those that have excellent adsorption ability for water and have the property that the adsorbed water can exist as surface hydroxyl groups, chemically adsorbed water, and physically adsorbed water. and specific [is tin dioxide (Sn02),
Zinc oxide (ZnO), aluminum oxide (A40s)
*Magnesium oxide (MgO).

Calcium oxide (Cab), strontium oxide (Sr)
O), barium oxide (Bad), titanium dioxide (T
iOt)-silicon dioxide (Si02), each singly or optionally in combination of 2# or more.

In addition, the metal oxide with oxygen adsorption ability used in the present invention is: Oxygen molecules (02
), or has the property of adsorbing as ions (02+ 0'''s O2), specifically, tin dioxide (Sn02), zinc oxide (ZnO), cupric oxide (Cu20) , -manganese oxide (MnO), nickel oxide (Nip), copal tetroxide) (CO304
) may be used alone or in any combination of 2wi or more. Among these, SnOz l
ZnO is particularly useful.

Furthermore, the metal oxide with the rutile type crystal structure in the present invention is represented by the chemical formula A (h), and the coordination polyhedron is a dioctahedron, and the &: all of these octahedrons are arranged one-dimensionally. Refers to a substance having a structure in which aggregates are combined, specifically, tin dioxide (SnOz), titanium dioxide (T102) l
Vanassium dioxide (Vow), molybdenum dioxide (Mo
02), tungsten dioxide (W(h), rubidium dioxide (RuOz), niobium dioxide (NbOz), chromium dioxide (Cr(h), rhenium dioxide (α-3e0)
2) Osmium dioxide (OsO2), rhodium oxide (Rh02), and iridium dioxide (IrOz).

Platinum dioxide (Pt02) alone or 2f, +1
Examples include complexes in which one or more of them are combined arbitrarily.

Among these, Snow + TiOi is particularly useful.

The thickness of these metal oxide thin films is preferably in the range of 0.01 to 1.0 μm for the same reason as in the case of polymer thin films.

The air % electrode of the present invention having the above structure can be manufactured by the following method.

The first method is to directly form a Y film on a polymer with a constant thickness of /9r using a commonly used plasma polymerization method on the gas side surface of the electrode body, and then apply a vapor deposition method, sputtering method, etc. on this film. In this method, the metal oxide is completely destroyed by a commonly used tactile forming method to form a thin Jlu of a predetermined thickness.

The second method is to first form a thin polymer film on one side of a flexible porous membrane having 5 micropores with a pore diameter of 0.1 μm or less using a plasma polymerization method, and then apply an evaporation method or A layer of metal oxide is formed by a sputtering method to form a composite thin film with a three-layer structure, and then the other surface of this composite thin film, that is, the other surface of the porous film, is applied to the gas side surface of the electrode body. 1. In both the first method and the second method, if a thin shadow of metal oxide is formed, the evaporation source or sulfur 4 is used. Although these Kinzo oxides themselves can be used as a source of ivy, it is also possible to use Kinzo alone as a vapor deposition source or sputtering source, which reacts with oxygen to produce these gold hU oxides ql!/J. It is preferable to set the atmosphere to be an oxygen atmosphere (VC) because the super-deformation rate of the metal oxide increases and the operation for forming a thin film becomes easier.

Furthermore, the porous membrane used in the second method has a pore diameter of 0.
Any material may be used as long as it has micropores of 1 μm or less. For example, porous fluororesin membranes (trade name, Fluoropore; manufactured by Sumitomo Electric Industries, Ltd.), porous polycarbonate membranes (trade name, Nuclepore Corporation W), porous cellulose ester membranes (trade name, Millipore membrane), Filter: Millibore Corporation
t), porous polypropylene membrane (trade name, Celgard;
Examples include flexible porous membranes such as those made by Celanese Plastics. In a porous film, if the pore diameter exceeds 1 μrrL, pinholes are likely to occur in the thin film when a polymer thin film or metal oxide thin film is formed by plasma polymerization to remove the porosity. As the thin film loses its function, its mechanical strength also decreases, making it more susceptible to breakage.

The thus staged air frost of the present invention is incorporated into a battery according to a very conventional method. In this case, when performing intermittent discharge, an instantaneous large current can be supplied not only by electrochemical reduction of oxygen gas but also by electrochemical reduction of the electrode components themselves. It is preferable to integrally attach a porous layer containing at least an oxide or a hydroxide to the electrolyte side of the electrode body, whose oxidation state changes depending on a base potential within a range of 4 V. . This porous layer is decomposed by oxygen gas by local cell action during discharge under a light load or when the circuit is opened, and is then returned to its original oxidized state.

As a constituent material of such a porous layer, Ag2O+M
Examples include n 02 + C020s, P b 02 + various perovskite type oxides, and spinel type oxides.

On the other hand, the air electrode is not only incorporated into a battery in the form of a plate, but may also be incorporated into a cylindrical battery, in which case the plate-shaped air electrode may be wound to form a cylinder. In such a case, in order to prevent damage to the pneumatic metal during winding work and to provide stability, a porous fluorocarbon resin is further added to the gas side surface of the water-containing or water-friendly metal oxide thin film. Membrane, porous polycarbonate membrane, porosity 48.1! Lulose ester membrane, porous polypropylene 1b! It is preferable to attach a porous thin film such as the like in the entire structure.

[Inventive ability side]

Examples 1 to 9 A Raney nickel plate (thickness: 200 μm) with an average pore diameter of 5 μm and a porosity of 80% was used as the rIJi pole body. This was loaded into a plasma reaction tank, and a high frequency power of 13.561 VIHz was applied from the outside, and argon was heated at 600 m/mi inside the tank.
nSA! Ntafluorostyrene monomer gas 600
Introducing m/min f, RF output 0.4W/ctA
The plasma polymerization reaction was carried out under the conditions of
(D Piece Tfn K A thin film of pentafluorostyrene polymer having a thickness of 0.2 μm was entirely formed.

Then, Sn y Zn t AL y Mg + C
a + S r p Ba *Ti, Si was used as a sputtering source, and a mixed gas of argon and oxygen (Ar90 vo7%) was used at a pressure of 2 X 10-3 Torr.

0210VOL%) and a high frequency power of 100 W under sputtering conditions-c sputter treatment to form a thin film of each hydrous or hydratable total polar oxide on the film of the pentafluorostyrene polymer. The thickness of the #film is 0.1 μm.

Next, these were immersed in a 2% parasol solution and sanded to give a particle size of approximately 0.5 μm, including the inside of the Raney nickel pores.
The air 14J of the present invention is precipitated with /f2 soum at a thickness of m.
, pole.

Examples 10 to 18 A 5 μm thick porous polycarbonate membrane (trade name: 2NucryBore, NucryBore Corporation!!) in which pores with an average pore diameter of 0.03 μm are uniformly distributed was loaded into a plasma reaction tank. , fully applied 13.56MHz high frequency power from the outside, Arbo 7 '600m1! /min
.

Pentafluorobenzene monomer gas 600+d/mi
After introducing n, a plasma polymerization reaction was carried out under the condition of RF output of 0.4 W/d, and a plasma x combination oNjl of pentafluorobenzene was formed on one side of the polycarbonate film. Thickness: 0.2 μnL.

Next, a thin film of a water-containing or water-friendly metal oxide was formed on the plasma-enriched rlJ JUO under the same sputtering conditions as in Examples 1 to 9. Thickness (), 1 μm.

The obtained composite thin film polycarbonate film flIi+,
It was brought into contact with one side of the Raney nickel plate having the same specifications used in Examples 1 to 9, and was crimped (-
It has an integrated structure.

Next, these were N-polarized in a palladium dichloride solution to deposit palladium of about 0.5 μm including the inside of the pores of the cine-nickel plate, thereby forming an air electrode.

Examples 19-22 In Examples 1 to 9, Cu was used as the suction ivy source.

The thrust electrodes fj and iJl were constructed in the same manner as in Examples 1 to 9, except that Mn, Ni, and Co were used, and therefore the formed metal oxide thin film had an oxygen adsorption capacity ft. did.

Examples 23 to 26 Air electrodes were manufactured in the same manner as in Examples 1O to 18 except that Cu, Mn, Ni, and Co were used as the sputter source. Examples 27 to 37 As the sputter source, V , Mo, W+Ru,
Nb, Cr.

Air% was prepared in the same manner as in Examples 1 to 9, except that Re, Os, Rh, Ir, and Pte were used, and the thin film of the metal enemy formed by force was made of rutile.
．． Manufactured poles.

Examples 38 to 48 As a sputtering source, V, Mo, W, Ru,
Nb + Cr+1”-e+ Os + Rh +
Air'rLL was completely produced in the same manner as in Examples 1() to 18 except that Ir+Pt'fc was used.

Comparative Example 1 Activated carbon powder was suspended in an aqueous solution of palladium chloride, and then reduced with formalin to obtain activated carbon powder.

Next, this powder was subjected to a 10-15% polyetrafluoroethylene waterproofing treatment, mixed with PTFE powder as a binder, and then rolled into a sheet. This sheet was pressed onto a nickel net to form an electrode body with a thickness of 0.6 m. Next, add artificial graphite powder l)
After the TFE dispersion was completely mixed, it was heat-treated to obtain waterproof graphite powder, which was then completely mixed with PTFE powder as a binder and rolled. The obtained sheet was crimped to the above-mentioned electrode body to form an air electrode having a thickness of 1.6.

Comparative Example 2 Polysiloxane film (thickness 5
0 μm) was crimped onto one side of a Raney nickel plate (thickness 200 μm) with an average pore diameter of 5 μm and a porosity of 80.The whole was then cathodically polarized in a 2% palladium chloride solution to form a 0.5 μm layer including the inside of the pores of the Raney nickel plate. palladium was deposited to form an air electrode.

Comparative Example 3 Air 1 produced in Comparative Example 1 (A water vapor absorbing layer of calcium chloride was attached to the air side of the pole.

Comparative Example 4 A porous polycarbonate having a thickness of 5 μm in which fine pores with an average pore diameter of 0.15 μm are distributed was coated on one side of Nate-Kin (trade name, Nuclepore, $2) under the conditions of Examples 1 to 90 to a thickness of 0.15 μm. A 2 μm thick interfluorostyrene fkL was completely formed by plasma polymerization, and a 0.1 μm thick SnOz sputtered film was further formed thereon under the same conditions.

The other surface of the obtained composite membrane was pressed onto a Raney nickel plate having the same specifications as in Examples 1 to 9 to form an air electrode.

Comparative Example 5 A porous polycarbonate film with an average pore diameter of 0.03 μm was used, and the thicknesses of the pentafluorostyrene plasma polymerized film and the SnOm snow vine film were 0 and 0 0 5, respectively.
The air electrode was entirely manufactured in the same manner as in Comparative Example 4, except that the thickness was μm.

Comparative Example 6 Thickness of plasma polymerized film of pentafluorostyrene is 2.0
11m% SnOs sputtered film thickness is 1.0μ
An air electrode was manufactured in the same manner as in Comparative Example 5, except that fi was used.

An air-zinc battery was assembled using 54 air electrodes as described above, a counter electrode in the form of mercury amalgamated zinc having a weight ratio of 3, an electrolyte as potassium hydroxide, and a separator as a polyamide nonwoven fabric.

After leaving these 54 batteries in air at 25° C. for 16 hours, they were discharged for 5 minutes at various @ currents, and the current density when the terminal voltage became 1.0 V or less after 5 minutes was measured. Also,
These batteries were stored in an atmosphere of 45° C. and 90% relative humidity, and leakage of the electrolyte was observed.

Furthermore, the same discharge test as above was performed on the frost pond after storage, and the ratio of the current value to the initial current value (%
) was calculated. This calculated value can be said to be the discharge characteristic maintenance rate for the entire degree of deterioration of the air electrode of each battery. An electrode with a large value indicates that the deterioration is small.

Also, each tI! V! Regarding the thin film attached to iv,
rR by using a gas chromatograph as a gas detection means, etc.
Measure the elementary gas permeation rate and measure the water vapor permeation rate using JISZO
208 (cup method) K was measured, and the total ratio between the two was calculated.

The above results are summarized in the table.

〔Effect of the invention〕

The air electrode of the present invention has an extremely thin composite thin film that has no pinholes and has oxygen gas selective permeability, which is integrally provided on the gas side surface of the electrode body. Elements that have some influence on electrode reactions will no longer enter the battery. The rice supply and battery storage performance are improved, and even during discharge, the discharge characteristics are maintained for a long period of time. Amazingly, it also improves leakage resistance.

Claims (1)

[Claims] 1. A porous electrode body that has an electrochemical reducing ability for oxygen gas and also has a current collector function; .1μrr
A polymer thin film formed by laminating one body by plasma polymerization via a porous membrane having micropores of L or less;
Furthermore, the air 'i'i'i' is characterized by comprising a thin film of a metal oxide which is integrally formed on the thin polymer film.
: 11Ii! ,. 2. The air electrode according to claim 1, wherein the polymer thin film is made of a monomolecular plasma polymer of a fluorinated organic compound. 3. The total pore oxide is selected from the group of tin dioxide, zinc oxide, aluminum oxide, magnesium oxide, calcium oxide, strontium oxide, barium oxide, titanium dioxide, and silicon dioxide. The air electrode according to claim 1, which is a water-containing or hydratable powdered metal. 4. The metal weathered material is tin dioxide, zinc oxide, oxide^
The air electrode according to claim 1, which is a metal oxide having an oxygen adsorption ability of at least one selected from the group consisting of manganese oxide, nickel oxide, and tricobalt tetroxide. 5 The total pore oxides include tin dioxide, titanium dioxide, diferent 1 [4 panasium, molybdenum dioxide, tungsten dioxide, rubidium dioxide, niobium dioxide, chromium dioxide, rhenium dioxide, osmium dioxide, rosium dioxide, iridium dioxide, platinum dioxide. The air electrode according to item 1, which is a complete oxide having a rutile-type crystal structure selected from the group consisting of: 6. The air electrode according to claim 1 or claim 2, wherein the polymer thin film has a thickness of 01 to 1.0 μm. 7. The thickness of the metal oxide thin film is 0.01 to 1.0
The air electrode according to any one of claims 1, 3, 4, and 5, which is μm. 8. A thin polymer film is entirely formed by plasma polymerization on the gas side surface of a porous electrode body that has an electrochemical reducing ability for oxygen gas and also has a current collector function, and then the polymer is A method for producing an air electrode, characterized by forming a thin film of metal oxide on top of a thin film. 9. The method for producing an air electrode according to claim 8, wherein the polymer film is made of a monomolecular plasma polymer of a fluorinated organic compound. 10. The metal oxide has at least one hydrous or water-containing glaze selected from the group of tin dioxide, zinc oxide, aluminum oxide, magnesium oxide, calcium oxide, strontium oxide, tin oxide, titanium dioxide, and silicon dioxide. 9. The method for producing an air electrode according to claim 8, wherein the air electrode is a l-type metal oxide. 11. A metal oxide in which the gold P oxide has an oxygen adsorption ability of at least one selected from the group of tin dioxide, zinc oxide, cuprous oxide, manganese oxide, nickel oxide, and tricobalt tetroxide. Claim 8: A method for manufacturing an air electrode, which is a product. 12 The metal oxide is tin dioxide, titanium dioxide,
At least one metal with a rutile-type crystal structure selected from the group of vanadium dioxide, molybdenum dioxide, tungsten dioxide, rubidium dioxide, niobium dioxide, chromium dioxide, rhenium dioxide, osmium dioxide, roseum dioxide, iridium dioxide, and di-variant platinum. The method for producing an air electrode according to claim 8, wherein the air electrode is an oxide. 13 The thickness of the polymer thin film is 0.01 to 1.0 μm
A method for manufacturing an air electrode according to claim 8 or claim Vi 9. 14. The thickness of the metal oxide thin film is 0.01 to 1.0
Claim 9A Items 8, 10, and 11 are μm.
The method for manufacturing an air electrode according to any one of Items 1 and 12. 15. A thin polymer film is formed by plasma polymerization on one side of a porous membrane having micropores with a pore size of 0.1 μm or less, and a metal oxide is further deposited on the thin polymer film. A thin film of metal oxide is formed, and then the other side of the porous film is attached to the gas side of a porous electrode body that has an electrochemical reducing ability for oxygen gas and also has a current collector function. A method for producing an air electrode characterized by crimping and integrating it onto a surface. 16. The method for producing an air % I pole according to claim 15, wherein the polymer thin film is made of a monomolecular plasma polymer of a fluorinated organic compound. 17. The metal oxide is at least one hydrous or hydratable metal oxide selected from the group of tin dioxide, zinc oxide, aluminum oxide, magnesium oxide, calcium oxide, strontium oxide, barium oxide, titanium dioxide, and silicon dioxide. The method for producing an air electrode according to claim 15, wherein the air electrode is an oxide. 18. The metal oxide is a metal oxide having an oxygen adsorption ability of at least one selected from the group of tin dioxide, zinc oxide, cuprous oxide, manganese oxide, nickel oxide, and tricobalt tetroxide. A method for manufacturing an air electrode according to claim 15. 19, the metal oxide is tin dioxide, titanium dioxide, vanadium dioxide, molybdenum dioxide, tungsten dioxide, rubisium dioxide, niobium dioxide, chromium dioxide,
rhenium dioxide, osmium dioxide, rhodium dioxide,
Claim 15'i3 A method for producing an air box and a pole, which are at least one metal oxide having a rutile crystal structure selected from the group of iridium dioxide and platinum dioxide. 20. The thickness of the polymer thin film is 0. The air according to claim 15 or 16, which has an O1 to 1.0 μm!
, i manufacturing method. 21. The thickness of the metal oxide thin film is 0.01 to 1.0
Claims 15, 17, and 18 that are μm.
The method for manufacturing an air electrode according to any one of Items 1 and 20.