JP2015079593A - Positive electrode for air batteries, and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a positive electrode for air batteries which enables the materialization of a higher output of an air battery by achieving both of gas permeability and a conductivity, and is useful in series connection of air batteries.SOLUTION: A positive electrode 10 for air batteries comprises a metal porous material layer 13, a liquid-tight gas-permeable layer 12 and a catalyst layer 11 which are laminated in turn, and an adhesion layer 14 between the metal porous material layer 13 and the liquid-tight gas-permeable layer 12 for gluing the layers together. In the positive electrode, the metal porous material layer 13 has many holes 13A piercing it in a thickness direction thereof, and the liquid-tight gas-permeable layer 12 has conductivity. Therefore, the metal porous material layer 13 superior in gas permeability, and the liquid-tight gas-permeable layer 12 having conductivity are put in close contact with each other with the aid of the adhesion layer 14. Thus, a higher output of an air battery is realized while achieving both gas permeability and conductivity. This is useful for series connection of air batteries.

Description

  The present invention relates to a positive electrode used for an air battery and a method for producing the same.

  The air battery uses oxygen in the air as an active material, and is a power source that is economical and can be used without maintenance for a long time. As a conventional air battery, a metal positive electrode case having an air hole and a metal negative electrode case are fitted together via a gasket to form a case fitting body, and in the internal space of the case fitting body, a negative electrode, an electrolyte, A button type air battery having a structure in which a separator, an air electrode (positive electrode), a water repellent film, and the like are arranged is known.

  In the button type air battery, the internal space of the case fitting body is divided by a separator, and one space is filled with zinc and an electrolyte solution impregnated therein to form a negative electrode, and a catalyst is disposed in the other space. Air electrode (positive electrode). In addition, a water repellent film made of a polytetrafluoroethylene (PTFE) porous film is disposed on the surface of the air electrode opposite to the separator, and diffusion paper is provided in close contact with the water repellent film. Yes.

  In the button type air battery, oxygen in the air as the positive electrode active material is taken in from the air hole formed in the bottom of the positive electrode case and supplied to the air electrode through the diffusion paper and the water repellent film. Is done. In this case, the diffusion paper functions to uniformly supply oxygen to the entire surface of the air electrode, and the water repellent film supplies oxygen to the inside of the battery (positive electrode), and the electrolyte solution is supplied to the outside of the battery through the air holes. It functions to prevent leakage.

  In the air battery having the above-described configuration, the catalyst layer is laminated on the gas diffusion layer, the current collector is unevenly arranged on the gas diffusion layer side in the catalyst layer, and the top of the catalyst layer is formed from the gas diffusion layer. An air battery having a truncated cone-shaped air electrode having a reduced diameter in the direction of the surface is known (for example, see Patent Document 1).

  In the button type air battery, when the battery is manufactured, the catalyst layer is hardly collapsed and the contact property between the catalyst layer side peripheral surface and the inner wall of the positive electrode case is good, so that the battery internal resistance can be reduced. Moreover, since it can suppress that the block-shaped catalyst which a catalyst layer collapse | crumbles and generate | occur | produces as a foreign material is pinched | interposed between battery component parts, it is known that it is excellent in leak-proof property.

Japanese Patent Laid-Open No. 11-54130

  However, in such a conventional button type air battery, leakage of the electrolyte solution due to the bulk catalyst can be prevented, but leakage of the electrolyte solution from the air hole is still separate from the air electrode (positive electrode). The water-repellent film made of PTFE film provided on the surface could only be prevented. In addition, when such a water-repellent film is provided, the conductivity is lowered, and therefore a current collector such as a metal net has to be provided in the catalyst layer.

  The present invention has been made in view of such problems of the prior art, and an object of the present invention is to achieve high output of an air battery by achieving both gas permeability and conductivity, and an air battery. It is an object of the present invention to provide a positive electrode for an air battery and a method for producing the same that are useful for serial connection of the above.

  The positive electrode for an air battery according to the present invention has a structure in which a metal porous body layer, a liquid-tight ventilation layer, and a catalyst layer are sequentially laminated, and both are disposed between the metal porous body layer and the liquid-tight ventilation layer. It has an adhesive layer for bonding. The positive electrode for an air battery is characterized in that the metal porous body layer has a large number of holes penetrating in the thickness direction, and the liquid-tight ventilation layer has conductivity.

  The method for producing a positive electrode for an air battery according to the present invention includes a liquid-tight air-permeable layer ink for forming a liquid-tight air-permeable layer and an adhesive layer for forming an adhesive layer. The step of adjusting the ink and the adhesive layer ink is applied on the holding body, and after the metal porous body layer is stacked thereon, the applied adhesive layer ink is dried and baked to form the adhesive layer And a step of peeling the metal porous body layer and the adhesive layer from the holding body. Then, in the above production method, after the metal porous body layer is disposed on the holding body with the adhesive layer facing upward, the liquid-tight air-permeable layer ink is applied to the adhesive layer of the metal porous body layer and dried. And a step of forming a liquid-tight ventilation layer by firing.

  According to the present invention, since the metal porous body layer having excellent gas permeability and the liquid-tight ventilation layer having conductivity are brought into close contact with each other by the adhesive layer, good gas permeability and thickness direction A positive electrode for an air battery that is useful for series connection of air batteries and a method for manufacturing the same. Can do.

It is sectional drawing (A) explaining the positive electrode in 1st Embodiment of the positive electrode for air batteries concerning this invention, and the fragmentary sectional view (B) which shows a microstructure roughly. It is sectional drawing which shows an example of the assembled battery of the series type air battery using the positive electrode for air batteries shown in FIG. It is each perspective view (A)-(F) explaining 1st Embodiment of a manufacturing method. It is each perspective view (A)-(E) explaining 2nd Embodiment of a manufacturing method. It is each perspective view (A)-(D) explaining 3rd Embodiment of a manufacturing method. It is each perspective view (A)-(E) explaining 4th Embodiment of a manufacturing method. It is each perspective view (A)-(E) explaining 5th Embodiment of a manufacturing method. It is the SEM photograph (A) and the SEM photograph (B) which expanded the B section in FIG.

<First Embodiment of Positive Electrode>
The positive electrode 10 for an air battery shown in FIG. 1 (A) has a structure in which a metal porous body layer 13, a liquid-tight ventilation layer 12 and a catalyst layer 11 are laminated in this order from the upper side. The metal porous body layer 13 is on the outside to constitute the battery appearance. Further, the positive electrode 10 has an adhesive layer 14 between the metal porous body layer 13 and the liquid-tight ventilation layer 12 for adhering both. Further, in the positive electrode 10, the metal porous body layer 13 has a large number of holes 13 </ b> A penetrating in the thickness direction, and the liquid-tight ventilation layer 12 has conductivity.

  In the present specification, for convenience of explanation, it has been described that the layers 11 to 13 are “laminated”, but it is sufficient that the layers are arranged in order as shown in the figure, and the term “laminated” is not necessarily limited. It is not something.

  The catalyst layer 11 includes carbon particles 1, carbon black 1 b as an example of a conductive path material, catalyst particles 3, and a binder 2, and the carbon particles 1, carbon black 1 b, and catalyst particles 3 are bound by the binder 2. Thus, a porous layer is formed.

  As a more preferred embodiment, the liquid-tight ventilation layer 12 contains a conductive path material composed of aggregates of primary particles of conductive carbon, and further includes a porous material composed of the conductive path material and conductive carbon particles. A porous layer containing body constituting particles can be formed. The illustrated liquid-tight ventilation layer 12 includes graphite 1a which is an example of aggregate carbon, carbon black 1b, and a binder 2, and the graphite 1a and the carbon black 1b are bound by the binder 2 to be porous. Forming a layer.

  The metal porous body layer 13 is, for example, a metal mesh, and has a large number of holes 13A penetrating in the thickness direction arranged vertically and horizontally. Specifically, the metal porous body layer 13 can employ any one of a metal etching plate, a punching metal, and an expanded metal in addition to a metal mesh. As the metal porous body layer 13, as a more desirable embodiment, a material having a surface roughness higher than the surface roughness of the surface facing the liquid-tight ventilation layer 12 is adopted in the surface of the hole 13 </ b> A. be able to.

  The metal porous body layer 13 is composed of a “porous body” as a metal member having a hole 13A such as a through-hole as described above, and is like the catalyst layer 11 or the liquid-tight ventilation layer 12. This is different from “porous” as a composition having fine pores.

  The adhesive layer 14 adheres the interface between the metal porous body layer 13 and the liquid-tight air-permeable layer 12 and preferably has electrical conductivity, but if it is thin enough to obtain electrical contact, it is insulated. It can also be used for sex. As the more preferable embodiment, the adhesive layer 14 may be one containing a conductive material. The conductive material may be at least one of metal, carbon particles such as the illustrated carbon black 1b, and carbon fiber. Some contain one. Further, as a more desirable embodiment, the adhesive layer 14 has liquid repellency with respect to the electrolytic solution, corrosion resistance with respect to the electrolytic solution, and gas permeability.

  In the present embodiment, the catalyst layer 11 and the liquid-tight ventilation layer 12 are bound together by the binder 2 and are almost integrated. Further, in the liquid-tight ventilation layer 12 and the metal porous body layer 13, Are substantially integrated by the adhesive layer 14. Such integration of the respective layers can be performed by a method for manufacturing a positive electrode for an air battery, which will be described later.

  Further, in the present embodiment, fibrous carbon (not shown) made of conductive carbon can be added to the catalyst layer 11 and / or the liquid-tight ventilation layer 12, thereby obtaining a positive electrode machine. Strength, particularly tensile strength, can be improved. The addition of the fibrous carbon is particularly preferably performed on the liquid-tight ventilation layer 12, and the layer thickness can be reduced by improving the mechanical strength, so that the electric resistance can be reduced, and thereby the output of the positive electrode can be increased. It is.

  As described above, both the catalyst layer 11 and the liquid-tight ventilation layer 12 are porous layers. In particular, the liquid-tight ventilation layer 12 allows oxygen in the air to permeate and does not allow electrolyte solution (not shown) to permeate. It has a pore diameter and a porosity. The metal porous body layer 13 itself is a conductive member, and gas permeation in the thickness direction is free by a large number of holes 13A. Further, the adhesive layer 14 also has conductivity, water repellency, and gas permeability as described above.

  Furthermore, unlike the conventional PTFE water-repellent film, the liquid-tight air-permeable layer 12 has conductivity by the graphite 1a that is the aggregate carbon and the carbon black 1b that is the conductive path material, and will be described below. Thus, it is extremely advantageous for constructing a series type air battery having a large electromotive force, and is more easily bonded by the adhesive layer 14.

  FIG. 2 is a schematic cross-sectional view showing an example of an assembled battery of series air batteries using the positive electrode for an air battery of the present invention. In the air battery A and the air battery B constituting the assembled battery, the positive electrode 10 formed by laminating the catalyst layer 11, the liquid-tight ventilation layer 12, the adhesive layer 14, and the metal porous body layer 13 and the negative electrode 20 are an electrolyte solution. It adjoins through the separator 30 impregnated with. The liquid-tight ventilation layer 12 of the positive electrode 10 is exposed to the air flow path 40 through the hole 13A of the metal porous body layer 13, and passes through the metal porous body layer 13 and the liquid-tight ventilation layer 12 to the catalyst layer 11 in the air. This structure is supplied with oxygen.

  In the illustrated example, in the air battery A and the air battery B, a holder 60 is disposed on the outer periphery of the positive electrode 10 and the negative electrode 20, and the outer periphery of the positive electrode 10 and the negative electrode 20 and the holder 60 are integrally joined. Thus, the electrolyte solution is prevented from leaking from the joint between the positive electrode 10 and the negative electrode 20 and the holder 60. Further, the air flow path 40 between the air battery A and the air battery B is provided with a current collector 50 having a corrugated cross section. Thus, the battery pack A is formed by adopting a stack structure in which the air batteries A and B are stacked via the current collector 50.

  In the positive electrode 10 for an air battery having the above-described configuration, the metal porous body layer 13 having excellent gas permeability and the liquid-tight air-permeable layer 12 having conductivity are brought into close contact with each other by the adhesive layer 14. The contact resistance at the interface is greatly reduced. FIG. 8 shows an SEM photograph of the positive electrode 10.

  As a result, the positive electrode 10 can achieve both good gas permeability and good conductivity in the thickness direction and in-plane direction, thereby realizing high output of the air battery and air battery. This is useful for serial connection. Moreover, since the positive electrode 10 improves the output per unit area of the electrode of the air battery, it is possible to reduce the size of the electrode and the air battery as the output increases.

  Further, the positive electrode 10 can achieve further improvement in conductivity and gas permeability in the thickness direction by using the metal porous body layer 13 having a large number of holes 13A penetrating in the thickness direction. In addition, the positive electrode 10 uses a metal mesh, a metal etching plate, a punching metal, or an expanded metal as the conductive porous layer 13, so that the thin and high-strength metal porous layer is used. 13 can be obtained at a low cost, and the cost of the air battery can be reduced, the area of the electrode can be increased, and the output can be improved as the area is increased.

  Furthermore, the positive electrode 10 includes the liquid-tight ventilation layer 12 containing a conductive path material composed of aggregates of primary particles of conductive carbon, while ensuring good conductivity in the thickness direction, Gas permeability and electrolyte impermeability can be obtained, which can contribute to weight reduction of the air battery. Furthermore, the electrode 10 has a gas-diffusing property improved by making the liquid-tight ventilation layer 12 a porous layer containing the above-described conductive path material and porous body constituting particles composed of conductive carbon particles. It can contribute to high output of air battery. In addition, the liquid-tight ventilation layer 12 has a good contact state at the interface with the catalyst layer 11, and thus a three-phase interface between the catalyst 3, oxygen, and electrolyte is easily formed, which is efficient in an air battery. It will contribute to power generation.

  Furthermore, in the air batteries A and B and the assembled battery having the positive electrode 10 as one component, as described above, the metal porous body layer 13 and the liquid-tight ventilation layer 12 are in close contact with each other and have conductivity. As shown in the figure, the electrical connection between the opposing negative electrode 20 and positive electrode 10 is realized simply by arranging the current collector 50 in the air flow path 40. Specifically, an assembled battery in which the air battery A and the air battery B are connected in series can be easily obtained. In this case, since the negative electrode 20 and the positive electrode 10 have a large electrical contact area and can be electrically connected on the surface, it is possible to reduce energization loss. In the assembled battery, if the air introduction portion for the positive electrode 10 can be secured, the opposing negative electrode 20 and the positive electrode 10 can be brought into direct contact with each other.

  In contrast, when a conventional air battery using a PTFE water-repellent film is used and the air batteries are connected in series, when both batteries are stacked, the negative electrode of one battery and the positive electrode of the other battery are connected. It is impossible to make the electrical connection opposite to each other because the water-repellent film is insulative. Therefore, it is necessary to form tabs for electrical connection on the ends (side surfaces) of both batteries and connect the tabs to each other, which not only complicates the manufacturing process but also energizes only the tabs for electrical contacts. It has also been found that there is a drawback that the loss becomes large.

  Thus, the positive electrode 10 for an air battery of the present invention is typically suitable for forming a series assembled battery of air batteries A and B having a structure as shown in FIG. The series-type assembled battery having such a structure is easy to realize a large electromotive force, can be made compact, and can improve the assembling work efficiency, and is very useful as an in-vehicle power source.

  In the assembled battery shown in FIG. 2, an electrolyte solution (not shown) is impregnated in the separator 30, but the electrolyte solution may be in contact with the positive electrode and the negative electrode. May be filled with an electrolyte solution. Needless to say, the catalyst layer 11 and the negative electrode 20 may be impregnated and held in the positive electrode and the negative electrode.

  Furthermore, the positive electrode 10 further improves the conductivity in the thickness direction by containing at least one of metal, carbon particles, and carbon fibers as the conductive material in the adhesive layer 14. Further, the positive electrode 10 provides the air layer with a long life, light weight, and high output by providing the adhesive layer 14 with liquid repellency with respect to the electrolyte, corrosion resistance with respect to the electrolyte, and gas permeability. .

Next, the positive electrode for an air battery and the constituent materials of the air battery will be described.
<Conductive porous layer>
As described above, the conductive porous body layer can use any one of a metal mesh, a metal etching plate, a punching metal, and an expanded metal, and more specifically, a stainless steel etching plate or A punching metal made of aluminum or aluminum alloy.

<Conductive path material for liquid-tight ventilation layer>
Carbon black or acetylene black can be used as the conductive path material for the liquid-tight ventilation layer. When carbon black or acetylene black is used for the conductive path material, it is easy to make a structure, so the resistance in the thickness direction is reduced by electrically connecting the porous body constituting particles, and this makes the positive electrode It is possible to improve conductivity and increase the output of the air battery.

<Porous particles constituting liquid-tight ventilation layer>
Gas permeability can be improved by using carbon which is larger than carbon of the conductive path material and has many voids as the porous body constituting particles. As the porous body constituting particles, graphite (graphite), flaky graphite, or carbon fiber can be used.

  When graphite is used for the porous body constituting particles, gas diffusivity can be improved because gaps are easily formed when packed. Moreover, when scaly graphite is used for the porous body constituting particles, the conductivity in the in-plane direction is increased from the shape. Moreover, scale-like graphite is easy to align the direction even when the liquid-tight ventilation layer is made into a sheet, and it is easy to ensure strength even if it is thin, so the penetration resistance in the thickness direction is reduced, and gas diffusibility is also good Become. Furthermore, when carbon fiber is used for the porous body constituting particles, the conductivity in the in-plane direction is increased depending on the shape, and when the liquid-tight ventilation layer is formed into a sheet, the strength is ensured even if it is thin. Since it is easy, the penetration resistance in the thickness direction is reduced and the gas diffusibility is also improved.

<Catalyst layer components>
As the catalyst component, a conventionally known electrode catalyst for an air battery positive electrode can be used. Specifically, platinum (Pt), ruthenium (Ru), iridium (Ir), rhodium (Rh), palladium (Pd) , Osmium (Os), tungsten (W), lead (Pb), iron (Fe), chromium (Cr), cobalt (Co), nickel (Ni), manganese (Mn), vanadium (V), molybdenum (Mo) Examples thereof include metals such as gallium (Ga) and aluminum (Al) and compounds thereof, and alloys thereof.

<binder>
As binders, polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyethernitrile (PEN), polyacrylonitrile (PAN), polyimide (PI), polyamide (PA), cellulose, carboxymethylcellulose (CMC) , Ethylene-vinyl acetate copolymer, polyvinyl chloride (PVC), styrene / butadiene rubber (SBR), isoprene rubber, butadiene rubber, ethylene / propylene rubber, ethylene / propylene / diene copolymer, styrene / butadiene / styrene block Copolymers and their hydrogenated products, thermoplastic polymers such as styrene / isoprene / styrene block copolymers and their hydrogenated products, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTF) ), Tetrafluoroethylene / hexafluoropropylene copolymer (FEP), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), ethylene / tetrafluoroethylene copolymer (ETFE), polychlorotrifluoroethylene (PCTFE) ), Fluoropolymers such as ethylene / chlorotrifluoroethylene copolymer (ECTFE), polyvinyl fluoride (PVF), vinylidene fluoride-hexafluoropropylene-based fluororubber (VDF-HFP fluoropolymer), vinylidene fluoride-hexa Fluoropropylene-tetrafluoroethylene fluorine rubber (VDF-HFP-TFE fluorine rubber), vinylidene fluoride-pentafluoropropylene fluorine rubber (VDF-PFP fluorine rubber), vinyl Denfluoride-pentafluoropropylene-tetrafluoroethylene-based fluoro rubber (VDF-PFP-TFE-based fluoro rubber), vinylidene fluoride-perfluoromethyl vinyl ether-tetrafluoroethylene-based fluoro rubber (VDF-PFMVE-TFE-based fluoro rubber) And vinylidene fluoride-based fluororubber such as vinylidene fluoride-chlorotrifluoroethylene-based fluororubber (VDF-CTFE-based fluororubber), epoxy resin, and the like. Among these, polyvinylidene fluoride, polyimide, styrene / butadiene rubber, carboxymethyl cellulose, polypropylene, polytetrafluoroethylene, polyacrylonitrile, and polyamide can be exemplified. Such a binder may be used individually by 1 type, and may use 2 or more types together.

  Among these binders, from the viewpoint of heat resistance and chemical resistance, polytetrafluoroethylene (PTFE), polypropylene (PP), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene. -A hexafluoropropylene copolymer (FEP) and an ethylene-tetrafluoroethylene copolymer (ETFE) can be used particularly suitably.

<Adhesive layer components>
As the conductive material for the adhesive layer, polyacetylene, polyaniline, polythiophene and polypyrrole-based resin containing a conductive polymer, or carbon, metal and conductive oxide containing a conductive inorganic substance in the resin are used. Thus, even if the adhesive layer has a thickness, good conductivity can be ensured, and the output of the positive electrode and thus the air battery can be increased.

  The adhesive layer can contain at least one of a metal, carbon particles, and carbon fibers as a conductive material. As the metal-containing material, an adhesive in which metal particles such as a metal paste are dispersed, or a paste in which metal fibers are dispersed can be used. As the ink containing carbon particles or carbon fibers, an ink or paste in which conductive carbon such as carbon black is dispersed is used. Moreover, fibrous carbon, such as a carbon nanotube (CNT), can also be used. By including these conductive materials, the adhesive layer improves the adhesion and conductivity at the interface with the metal porous layer having a rough surface and the liquid-tight air-permeable layer having a high porosity. Achieve high output.

  Further, the adhesive layer has liquid repellency with respect to the electrolytic solution, and specifically, it is desirable to use a liquid repellent material for the binder. For example, when the electrolytic solution is water-based, a fluorine-based resin such as polytetrafluoroethylene (PTFE) or a water-repellent resin such as polypropylene (PP), polyethylene (PE), or polystyrene (PS) is used. Further, when the electrolytic solution is non-aqueous, it is desirable to use a fluorine-based resin such as polytetrafluoroethylene and have a contact angle with respect to the solvent of 80 ° or more. Adhesive layers using these materials can prevent deterioration and leakage of the interface with the liquid-tight ventilation layer, and can contribute to extending the life of the positive electrode and the air battery.

  Further, the adhesive layer has corrosion resistance to the electrolytic solution, and when an alkali-resistant binder is used for the liquid-tight air-permeable layer that contacts the interface, fluorine-based trees such as polytetrafluoroethylene, polypropylene, polyethylene, polystyrene, etc. Water repellent resin, engineering plastic such as fiber reinforced plastic (FRP), epoxy resin, vinyl chloride, etc. are used. Moreover, when an aluminum alloy is used for the metal porous body layer in contact with the interface, the adhesive layer is given an alkali resistance function to improve durability. The adhesive layer using these materials protects the metal porous body layer from the electrolytic solution.

  Furthermore, the adhesive layer is assumed to have gas permeability, specifically, it is made porous using carbon black or a PTFE-based binder, whereby not only the gas permeability in the thickness direction of the adhesive layer but also metal The gas can be diffused throughout the adhesive layer including the region covered with the porous porous body layer (the region that is not a hole).

<Negative electrode>
Examples of the negative electrode include a negative electrode active material made of a single metal or an alloy whose standard electrode potential is lower than that of hydrogen. In some cases, it can be formed of a porous material. Examples of simple metals whose standard electrode potential is lower than that of hydrogen include lithium (Li), zinc (Zn), iron (Fe), aluminum (Al), magnesium (Mg), manganese (Mn), silicon (Si), and titanium. (Ti), chromium (Cr), vanadium (V), and the like. An alloy can also be applied. However, the material is not limited to these, and a conventionally known material applied to an air battery can be used.

<Electrolyte>
A conventionally well-known thing can be used also for electrolyte solution, For example, aqueous solution and non-aqueous solutions, such as potassium chloride, sodium chloride, and potassium hydroxide, can be used.

<Separator>
A conventionally well-known material used for an air battery can be used as a separator. Specifically, for an electrolytic solution that is an aqueous solution, for example, a glass paper that has not been subjected to a water repellent treatment, or a microporous membrane made of polyolefin such as polyethylene or polypropylene can be suitably used.

<Current collector>
The current collector is not particularly limited as long as it has a current collecting function. For example, a current collector made of a metal such as stainless steel (SUS), copper, or nickel can be used. A material obtained by coating a resin with a conductive material can also be used. Further, the shape is not particularly limited, and various shapes such as a wire mesh shape, an expanded metal shape, and a corrugated plate shape can be applied.

Next, based on FIGS. 3-7, the manufacturing method of the positive electrode for air batteries of this invention is demonstrated.
<First Embodiment of Manufacturing Method>
The manufacturing method shown in FIG. 3 is a method for manufacturing the positive electrode for an air battery shown in FIG. 1, and adjusting the liquid-tight air layer ink for forming the liquid-tight air-permeable layer and the adhesive layer ink for forming the adhesive layer. A step of applying the liquid-tight air-permeable layer ink on the holding body, drying and firing the ink, and a step of peeling the formed liquid-tight air-permeable layer from the holding body. And a step of applying the adhesive layer ink to at least one of the liquid-tight air-permeable layer and the metal porous body layer, and the liquid-tight air-permeable layer and the metal porous body layer are overlapped with the applied adhesive layer ink interposed therebetween. Thereafter, the method includes a step of forming the adhesive layer by drying and baking the ink for the adhesive layer, and laminating the catalyst layer on the liquid-tight ventilation layer.

  That is, as shown in FIG. 3A, the liquid-tight air layer ink IA that forms the liquid-tight air layer and the adhesive layer ink IB that forms the adhesive layer are adjusted. The solvent used in preparing these inks is not particularly limited, and examples thereof include water, alcohol solvents such as methanol, ethanol, 1-propanol, 2-propanol, ethylene glycol, and propylene glycol. Each ink may be mixed with a known surfactant or thickener as necessary.

  Next, as shown in FIG. 3 (B), the liquid-tight ventilation layer 12 is formed by applying the liquid-tight ventilation layer ink IA onto the holding body H, drying it, and firing it. Thereafter, as shown in FIG. 3C, the formed liquid-tight ventilation layer 12 is peeled from the holding body H. Subsequently, the adhesive layer ink IB is applied to at least one of the liquid-tight ventilation layer 12 and the metal porous body layer 13. In this embodiment, as shown in FIG. 3D, the adhesive layer ink IB is applied to the metal porous body layer 13 using the brush D.

  Next, before the applied adhesive layer ink IB dries, as shown in FIG. 3E, the liquid-tight air-permeable layer 12 and the metal porous body layer 13 are interposed between the applied adhesive layer ink IB. Repeat. That is, in this embodiment, the liquid-tight ventilation layer 12 and the application surface of the adhesive layer ink IB of the metal porous body layer 13 are overlapped. Thereafter, as shown in FIG. 3 (F), the adhesive layer ink IB is dried and baked to form the adhesive layer 14, thereby bonding the metal porous body layer 13 and the liquid-tight air-permeable layer 12. Integrate with layer 14. Then, a catalyst layer (not shown) is laminated on the liquid-tight ventilation layer 12 to form the positive electrode 10.

  Note that the catalyst layer in this embodiment is laminated below the liquid-tight ventilation layer 12 shown in FIG. This catalyst layer can be formed by adjusting, applying, drying, and firing the ink for the catalyst layer, as with each layer.

  In the above production method, the drying temperature of the ink is not particularly limited as long as it is a temperature at which the solvent in the ink is removed, but is preferably set to 80 to 120 ° C., for example. Moreover, although baking temperature is not specifically limited, For example, it is preferable to set it as 100-350 degreeC. The same applies to the following embodiments.

<Second Embodiment of Manufacturing Method>
The manufacturing method shown in FIG. 4 is a method of manufacturing the positive electrode for an air battery shown in FIG. 1, and adjusting the liquid-tight air layer ink for forming the liquid-tight air-permeable layer and the adhesive layer ink for forming the adhesive layer. A step of forming an adhesive layer by applying an adhesive layer ink to the metal porous body layer, drying and firing the metal layer, and a metal porous body with the adhesive layer facing upward on the holder After the layer is disposed, a step of applying a liquid-tight air-permeable layer ink to the adhesive layer, and drying and baking the ink is formed, and a catalyst layer is laminated on the liquid-tight air-permeable layer. To do.

  That is, as shown in FIG. 4A, the liquid-tight air layer ink IA that forms the liquid-tight air layer and the adhesive layer ink IB that forms the adhesive layer are adjusted. Next, as shown in FIG. 4B, the adhesive layer ink IB is applied to the metal porous body layer 13, dried and fired to form the adhesive layer 14.

  Thereafter, as shown in FIG. 4C, the metal porous body layer 13 is disposed on the holding body H with the adhesive layer 14 facing upward, and then, as shown in FIG. The liquid-tight ventilation layer 12 is formed by applying the ink IA for the liquid-tight ventilation layer, drying it, and baking it. Thereby, the metal porous body layer 13 and the liquid-tight ventilation layer 12 are integrated by the adhesive layer 14. Then, as shown in FIG. 4E, the catalyst layer 11 is laminated on the liquid-tight ventilation layer 12 to form the positive electrode 10.

<Third Embodiment of Manufacturing Method>
The manufacturing method shown in FIG. 5 is a method of manufacturing the positive electrode for an air battery shown in FIG. 1, and adjusts the liquid-tight ventilation layer ink for forming the liquid-tight ventilation layer and the adhesive layer ink for forming the adhesion layer. Applying the ink for the adhesive layer to the metal porous body layer, drying and baking the ink for the adhesive layer, and applying the ink for the liquid-tight ventilation layer on the holding body, A step of superimposing an adhesive layer of a metal porous body layer on the liquid-tight ventilation layer ink, and a step of forming the liquid-tight ventilation layer by drying and baking the applied liquid-tight ventilation layer ink. A catalyst layer is laminated on the tightly ventilated layer.

  That is, as shown in FIG. 5A, the liquid-tight air layer ink IA that forms the liquid-tight air layer and the adhesive layer ink IB that forms the adhesive layer are adjusted. Next, as shown in FIG. 5B, the adhesive layer ink IB is applied to the metal porous body layer 13, dried, and fired to form the adhesive layer 14.

  Subsequently, as shown in FIG. 5C, after applying the liquid-tight air-permeable layer ink IA on the holding body H, before the applied liquid-tight air-permeable layer ink IA is dried, the liquid-tight air-permeable layer ink is used. The adhesive layer 14 of the metal porous body layer 13 is overlaid on the ink IA. Thereafter, the applied liquid-tight ventilation layer ink IA is dried and baked to form the liquid-tight ventilation layer 12. Thereby, the metal porous body layer 13 and the liquid-tight ventilation layer 12 are integrated by the adhesive layer 14. Then, as shown in FIG. 5D, a catalyst layer (not shown) is stacked on the liquid-tight ventilation layer 12 to form the positive electrode 10.

<Fourth Embodiment of Manufacturing Method>
The manufacturing method shown in FIG. 6 is a method of manufacturing the positive electrode for an air battery shown in FIG. 1, and adjusting the liquid-tight air layer ink for forming the liquid-tight air-permeable layer and the adhesive layer ink for forming the adhesive layer. A step of applying an adhesive layer ink on the holding body, and a metal porous body layer thereon, and then drying the applied adhesive layer ink and firing to form an adhesive layer; A step of peeling the metal porous body layer and the adhesive layer from the holding body, and after placing the metal porous body layer on the holding body with the adhesive layer facing upward, liquid-tight on the adhesive layer of the metal porous body layer A step of forming a liquid-tight gas-permeable layer by applying an ink for the gas-permeable layer, drying and baking the ink, and laminating a catalyst layer on the liquid-tight gas-permeable layer.

  That is, as shown in FIG. 6A, the liquid-tight ventilation layer ink IA that forms the liquid-tight ventilation layer and the adhesive layer ink IB that forms the adhesive layer are adjusted. Next, as shown in FIG. 6 (B), the adhesive layer ink IB is applied onto the holding body H, the metal porous body layer 13 is overlaid thereon, and then the applied adhesive layer ink IB is dried. Then, the adhesive layer 14 is formed by firing.

  Thereafter, the metal porous body layer 13 and the adhesive layer 14 are peeled from the holding body H, and then, as shown in FIG. 6C, the metal porous body with the adhesive layer 14 facing upward on the holding body H. After the layer 13 is disposed, as shown in FIG. 6D, the liquid-tight air-permeable layer ink IA is applied to the adhesive layer 14 of the metal porous body layer 13, dried, and fired. The ventilation layer 12 is formed. Thereby, the metal porous body layer 13 and the liquid-tight ventilation layer 12 are integrated by the adhesive layer 14. Then, as shown in FIG. 6E, the catalyst layer 11 is laminated on the liquid-tight ventilation layer 12 to form the positive electrode 10.

<Fifth Embodiment of Manufacturing Method>
The manufacturing method shown in FIG. 7 is a method of manufacturing the positive electrode for an air battery shown in FIG. 1, and adjusting the liquid-tight air layer ink for forming the liquid-tight air-permeable layer and the adhesive layer ink for forming the adhesive layer. A step of applying an adhesive layer ink on the holding body, and a metal porous body layer thereon, and then drying the applied adhesive layer ink and firing to form an adhesive layer; The step of peeling the metal porous body layer and the adhesive layer from the holding body, and the liquid-tight ventilation layer ink is applied on the holding body, and the adhesive layer of the metal porous body layer is overlaid thereon, followed by liquid-tight ventilation. A step of forming a liquid-tight ventilation layer by drying and firing the layer ink, and laminating a catalyst layer on the liquid-tight ventilation layer.

  That is, as shown in FIG. 7A, the liquid-tight air layer ink IA that forms the liquid-tight air layer and the adhesive layer ink IB that forms the adhesive layer are adjusted. Next, as shown in FIG. 7 (B), the adhesive layer ink IB is applied onto the holding body H, and before the applied adhesive layer ink IB is dried, the metal porous body layer 13 is formed thereon. Overlapping. Then, the adhesive layer 14 is formed by drying and baking the applied adhesive layer ink IB.

  Next, as shown in FIG. 7C, after the metal porous body layer 13 and the adhesive layer 14 are peeled from the holding body H, liquid-tight ventilation is performed on the holding body H as shown in FIG. The layer ink IA is applied, and before the applied liquid-tight air layer ink IA is dried, the adhesive layer 14 of the metal porous body layer 13 is superimposed on the liquid-tight air layer ink IA. Thereafter, the liquid-tight ventilation layer 12 is formed by drying and firing the liquid-tight ventilation layer ink IA. Thereby, the metal porous body layer 13 and the liquid-tight ventilation layer 12 are integrated by the adhesive layer 14. Then, as shown in FIG. 7E, a catalyst layer (not shown) is laminated on the liquid-tight ventilation layer 12 to form the positive electrode 10.

  Thus, the manufacturing method of the positive electrode for air batteries demonstrated in the said 1st-5th embodiment uses the metal porous body layer 13 and the inks IA and IB for each layer, and the metal porous to the holding body H is carried out. The positive electrode 10 in which the layers 11 to 14 are integrated can be manufactured by combining the arrangement of the body layer 13, the application of the ink to the metal porous body layer 13 and the holding body H, drying and baking. Such a positive electrode 10 has a small penetration resistance in the thickness direction and a very good conductivity, and a three-layer interface of oxygen, a catalyst component and an electrolyte between the liquid-tight ventilation layer 12 and the catalyst layer 11. Therefore, the battery output can be increased.

  Therefore, according to the above-described method for producing a positive electrode for an air battery, high output of the air battery can be realized by using a conventional technique for preparing an electrode while achieving both good gas permeability and good electrical conductivity. The positive electrode 10 can be easily manufactured at low cost.

  As mentioned above, although this invention was demonstrated by some embodiment, this invention is not limited to these, A various deformation | transformation is possible within the range of the summary of this invention. The positive electrode for an air battery of the present invention can also be applied to an electrode structure of a salt water battery.

DESCRIPTION OF SYMBOLS 1 Carbon particle 1a Graphite 1b Carbon black 2 Binder 3 Catalyst particle 10 Positive electrode 11 Catalyst layer 12 Liquid-tight ventilation layer 13 Metal porous body layer 13A Hole 14 Adhesive layer 20 Negative electrode layer 30 Separator (electrolytic solution)
40 Air channel 50 Current collector 60 Holder

Claims (19)

It has a structure in which a metal porous body layer, a liquid-tight ventilation layer and a catalyst layer are laminated in order,
Between the metal porous body layer and the liquid-tight ventilation layer, having an adhesive layer for adhering both,
The metal porous body layer has a large number of holes penetrating in the thickness direction,
The positive electrode for an air battery, wherein the liquid-tight ventilation layer has conductivity.   The positive electrode for an air battery according to claim 1, wherein the adhesive layer contains a conductive material.   The positive electrode for an air battery according to claim 2, wherein the adhesive layer contains at least one of a metal, carbon particles, and carbon fibers as a conductive material.   The positive electrode for an air battery according to any one of claims 1 to 3, wherein the adhesive layer has liquid repellency with respect to an electrolytic solution.   The positive electrode for an air battery according to any one of claims 1 to 4, wherein the adhesive layer has corrosion resistance to an electrolytic solution.   The positive electrode for an air battery according to claim 1, wherein the adhesive layer has gas permeability.   The air battery according to claim 1, wherein the conductive porous body layer is any one of a metal mesh, a metal etching plate, a punching metal, and an expanded metal. Positive electrode.   The positive electrode for an air battery according to any one of claims 1 to 7, wherein the liquid-tight air-permeable layer contains a conductive path material made of an aggregate of primary particles of conductive carbon.   2. The liquid-tight ventilation layer is a porous layer containing a conductive path material made of an aggregate of primary particles of conductive carbon and a porous material constituting particle made of conductive carbon particles. The positive electrode for air batteries of any one of -8.   The positive electrode for an air battery according to claim 9, wherein the porous body constituting particles are graphite.   The positive electrode for an air battery according to claim 9, wherein the porous body constituting particles are scaly graphite.   The positive electrode for an air battery according to claim 9, wherein the porous body constituting particles are carbon fibers.   The positive electrode for an air battery according to any one of claims 8 to 12, wherein the conductive path material is carbon black.   The positive electrode for an air battery according to claim 8, wherein the conductive path material is acetylene black. In manufacturing the positive electrode for an air battery according to any one of claims 1 to 14,
Adjusting the liquid-tight ventilation layer ink for forming the liquid-tight ventilation layer, and the adhesive layer ink for forming the adhesive layer;
A step of applying a liquid-tight ventilation layer ink on a holding body, and drying and baking the ink to form a liquid-tight ventilation layer;
Peeling the formed liquid-tight ventilation layer from the holding body;
Applying an adhesive layer ink to at least one of the liquid-tight ventilation layer and the metal porous body layer;
The step of forming the adhesive layer by drying and baking the ink for the adhesive layer, after the liquid-tight ventilation layer and the metal porous body layer are stacked with the applied adhesive layer ink interposed therebetween,
A method for producing a positive electrode for an air battery, wherein a catalyst layer is laminated on the liquid-tight ventilation layer. In manufacturing the positive electrode for an air battery according to any one of claims 1 to 14,
Adjusting the liquid-tight ventilation layer ink for forming the liquid-tight ventilation layer, and the adhesive layer ink for forming the adhesive layer;
A step of forming an adhesive layer by applying an adhesive layer ink to the metal porous body layer, drying and baking the ink;
After the metal porous body layer is arranged on the holding body with the adhesive layer facing upward, the liquid-tight ventilation layer ink is applied to the adhesive layer, dried and fired to form the liquid-tight ventilation layer. A method for producing a positive electrode for an air battery, comprising: laminating a catalyst layer on the liquid-tight ventilation layer. In manufacturing the positive electrode for an air battery according to any one of claims 1 to 14,
Adjusting the liquid-tight ventilation layer ink for forming the liquid-tight ventilation layer, and the adhesive layer ink for forming the adhesive layer;
A step of forming an adhesive layer by applying an adhesive layer ink to the metal porous body layer, drying and baking the ink;
After applying the liquid-tight air-permeable layer ink on the holding body, the step of overlaying the adhesive layer of the metal porous body layer on the liquid-tight air-permeable layer ink;
A method for producing a positive electrode for an air battery, comprising: a step of forming a liquid-tight gas-permeable layer by drying and baking the applied ink for the liquid-tight gas-permeable layer, and laminating a catalyst layer on the liquid-tight gas-permeable layer . In manufacturing the positive electrode for an air battery according to any one of claims 1 to 14,
Adjusting the liquid-tight ventilation layer ink for forming the liquid-tight ventilation layer, and the adhesive layer ink for forming the adhesive layer;
A step of forming an adhesive layer by applying an adhesive layer ink on a holding body, stacking a metal porous body layer thereon, and drying and baking the applied adhesive layer ink;
A step of peeling the metal porous body layer and the adhesive layer from the holding body;
After the metal porous body layer is disposed on the holding body with the adhesive layer facing upward, the liquid-tight air-permeable layer ink is applied to the adhesive layer of the metal porous body layer, dried, and fired. Comprising a step of forming a tightly ventilated layer;
A method for producing a positive electrode for an air battery, wherein a catalyst layer is laminated on the liquid-tight ventilation layer. In manufacturing the positive electrode for an air battery according to any one of claims 1 to 14,
Adjusting the liquid-tight ventilation layer ink for forming the liquid-tight ventilation layer, and the adhesive layer ink for forming the adhesive layer;
A step of forming an adhesive layer by applying an adhesive layer ink on a holding body, stacking a metal porous body layer thereon, and drying and baking the applied adhesive layer ink;
A step of peeling the metal porous body layer and the adhesive layer from the holding body;
A liquid-tight ventilation layer is formed by applying the liquid-tight ventilation layer ink on the holding body, overlaying the metal porous layer adhesive layer thereon, and drying and baking the liquid-tight ventilation layer ink. With a process,
A method for producing a positive electrode for an air battery, wherein a catalyst layer is laminated on the liquid-tight ventilation layer.

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