JP2010257839A - Positive electrode for air battery, and air battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive electrode for an air battery, which facilitates diffusing an oxygen-containing gas in the thickness direction, and to provide the air battery capable of increasing capacity and output. <P>SOLUTION: The positive electrode for the air battery has at least a first layer with a first supporting member having a hole and with a catalyst supported by the first supporting member, and a second layer with a second supporting member having the hole and with the catalyst supported by the second supporting member. In the positive electrode, the first and the second layers are laminated, and the diameter of the hole supported by the first supporting member is different from that supported by the second supporting member. The air battery is equipped with the positive electrode and a negative electrode for it, and an electrolyte to transfer ion in between the positive and the negative electrodes. Further in the air battery, the second layer is disposed in between the first layer and the electrolyte, and the diameter of the hole in the second supporting member is shorter than that in the first supporting member. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a positive electrode for an air battery and an air battery.

  The air battery is a battery using oxygen as a positive electrode active material, and an oxygen-containing gas is taken in from the outside during discharge. Therefore, it is possible to increase the proportion of the negative electrode active material in the battery container as compared with other batteries having positive and negative electrode active materials in the battery. Therefore, in principle, the electric capacity that can be discharged is large, and it is easy to reduce the size and weight. Further, since the oxidizing power of oxygen used as the positive electrode active material is strong, the electromotive force of the battery is relatively high. Furthermore, since oxygen has a feature that it is a clean material without resource restrictions, the air battery has a small environmental load. As described above, the air battery having many advantages is expected to be used for a hybrid vehicle battery, a portable device battery, and the like, and in recent years, there is a demand for higher performance of the air battery.

  In order to achieve high performance of the air battery, (1) stacking a plurality of air batteries, (2) increasing the thickness of the positive electrode (hereinafter sometimes referred to as “air electrode”) and the negative electrode. (3) It is conceivable to take measures such as increasing the area of the positive electrode or the negative electrode. However, in the measure (1), there is a problem that the energy density per volume of the whole battery tends to be reduced by using the laminate, and in order to solve such a problem, a plurality of air battery members are shared. Realization of such a structure is required. Further, the countermeasure (2) and the countermeasure (3) have a problem that oxygen supply to the positive electrode tends to stagnate. In order to solve such a problem, the positive electrode has a structure in which oxygen is easily diffused. Is needed.

  As a technique relating to such an air battery, for example, Patent Document 1 discloses an air battery including a positive electrode catalyst layer formed of at least two layers having different porosity. Patent Document 1 describes that positive electrode catalyst layers having different porosity are produced by adjusting the pressure of the rolling roller and the supply amount of the catalyst powder. Patent Document 2 discloses an air zinc battery using a nickel-iron alloy, an iron-nickel-chromium alloy, or a nickel-copper alloy as a core material of an air electrode.

JP-A-2005-19145 JP-A-9-92289

  According to the technique disclosed in Patent Document 1, since a positive electrode catalyst layer formed of at least two layers having different porosity is provided, a positive electrode in which oxygen easily diffuses if the pore diameter can be appropriately controlled. It is considered that an air battery having the above can be provided. However, the technique disclosed in Patent Document 1 has a problem that it is difficult to form a void having a large pore diameter, and thus the diffusion of the oxygen-containing gas in the thickness direction of the positive electrode tends to be delayed. Such a problem is difficult to solve even if the technique disclosed in Patent Document 1 and the technique disclosed in Patent Document 2 are combined.

  Then, this invention makes it a subject to provide the positive electrode for air batteries which can diffuse oxygen-containing gas to the thickness direction easily, and the air battery which can increase a capacity | capacitance and an output.

In order to solve the above problems, the present invention takes the following means. That is,
According to a first aspect of the present invention, there is provided a first support having holes and a first layer having a catalyst supported on the first support, a second support having holes, and the second support. A positive electrode for an air battery comprising at least a second layer having a catalyst, wherein the first layer and the second layer are laminated, and the hole diameter provided in the first support and the second support are provided. The positive electrode for an air battery is characterized in that the diameter of the hole is different.

  In the present invention, the diameter of the hole means the diameter of the hole when the hole is circular. Moreover, when a hole is square, it says the length of the one side. In addition, when the hole is a quadrangle other than a square, it means an average value of the lengths of two diagonal lines. Moreover, when a hole is a triangle or a polygon more than a pentagon, it means the diameter of a circle inscribed in the hole. In the present invention, the form of the first support and the second support is not particularly limited as long as the diameters of the holes provided in the first support and the second support are different. The first support and the second support may be made of a conductive material or may be made of an insulating material. When the first support is made of an insulating material, the first layer contains a conductive material in addition to the first support and the catalyst. When the second support is made of an insulating material, the second layer contains a conductive material in addition to the second support and the catalyst. On the other hand, when the first support is made of a conductive material, the first layer only needs to have the first support and the catalyst, and in addition to these, the conductive material is contained. Also good. When the second support is composed of a conductive material, the second layer only needs to have the second support and a catalyst, and in addition to these, a conductive material may be contained. . In the present invention, the first support and the second support are preferably made of a conductive material from the viewpoint of providing a high-performance positive electrode for an air battery by improving the electronic conductivity. Further, from the same viewpoint, the first layer is preferably in a form containing a conductive material in addition to the first support composed of the catalyst and the conductive material, and the second layer includes the catalyst and the conductive layer. In addition to the second support composed of the conductive material, it is preferable to further include a conductive material. When the first support is made of a conductive material, the first support can also function as a current collector for the positive electrode for the air battery. Similarly, when a 2nd support body is comprised with an electroconductive material, the said 2nd support body can also be functioned as a collector of the positive electrode for air batteries. In the present invention, the catalyst contained in the positive electrode for the air battery refers to a substance that functions as a catalyst for the reaction that occurs at the positive electrode of the air battery, and a known catalyst that can be used for the positive electrode of the air battery can be used as appropriate.

  In the first aspect of the present invention, the first support and / or the second support is preferably made of metal.

  In the present invention, examples of the metal support (first support and / or second support) include expanded metal, punching metal, metal nonwoven fabric, and foam metal.

  A second aspect of the present invention is an air battery comprising a negative electrode, a positive electrode to which an oxygen-containing gas is supplied, and an electrolyte solution that conducts ions between the negative electrode and the positive electrode. The positive electrode for an air battery according to the first aspect of the present invention, wherein the second layer is disposed between the first layer and the electrolytic solution, and the diameter of the hole provided in the second support is the first. It is an air battery characterized by being smaller than the diameter of the hole with which 1 support body was equipped.

  In the positive electrode for an air battery according to the first aspect of the present invention, a first support and a second support having different hole diameters are laminated. Since the first support and the second support are pre-formed with holes, according to the first aspect of the present invention, the first support and the second support having uniform and large holes are provided. It can be. By adopting such a configuration, it is possible to facilitate the diffusion of the oxygen-containing gas in the thickness direction. Therefore, according to the first aspect of the present invention, the oxygen-containing gas can be easily diffused in the thickness direction. It is possible to provide a positive electrode for an air battery capable of

  Moreover, in the 1st aspect of this invention, control of a hole diameter or a porosity becomes easy because a 1st support body and / or a 2nd support body are metal. Therefore, by adopting such a configuration, it is possible to provide a positive electrode for an air battery in which the oxygen-containing gas easily diffuses in the thickness direction.

  In the air battery according to the second aspect of the present invention, the positive electrode for an air battery according to the first aspect of the present invention is provided, and is provided between the first support body having a relatively large diameter hole and the electrolytic solution. A second support having a relatively small diameter hole is disposed. By setting it as this form, since the diameter of the hole in the area | region close | similar to electrolyte solution of a positive electrode can be made small, volatilization of electrolyte solution can be suppressed. In addition, since the diameter of the hole in the region of the positive electrode away from the electrolytic solution (region close to the oxygen-containing gas) can be increased, a large amount of oxygen-containing gas can be introduced into the positive electrode. By suppressing the volatilization of the electrolyte and introducing a large amount of oxygen-containing gas into the positive electrode, it becomes possible to increase the output and capacity of the air battery. According to the second aspect of the present invention, the output In addition, an air battery capable of increasing the capacity can be provided.

1 is a cross-sectional view showing an air battery 10. 1 is a cross-sectional view showing an air electrode 1. 2 is a cross-sectional view showing an air battery 20. FIG. 2 is a cross-sectional view showing an air electrode 11. FIG. It is a SEM photograph which shows the structure of a 2nd layer.

  In the air battery proposed so far, the structure of the air electrode has not been sufficiently controlled. For example, if the thickness of the air electrode is increased, the diffusion of the oxygen-containing gas in the air electrode may be insufficient. was there. As a result of diligent research, the present inventors have used an air electrode having a structure in which a plurality of supports carrying a catalyst, in which holes having different diameters are formed in advance, and by increasing the thickness, It has been found that an air electrode capable of sufficiently diffusing an oxygen-containing gas can be provided. In addition, it has also been found that it is possible to improve the performance of an air battery by adopting a configuration in which the air electrode is provided. Even if the thickness is increased, if the oxygen-containing gas can be sufficiently diffused into the air electrode, for example, when a plurality of air cells (single cells) are accommodated in the housing, the thickness is larger than the conventional case. It is possible to share a member by sharing a single thick air electrode with a plurality of single cells. Therefore, by providing an air electrode capable of sufficiently diffusing the oxygen-containing gas even if the thickness is increased, it is possible to solve the problems when the measures (1) to (3) are applied. It will be possible.

  The present invention has been made based on such knowledge. The main gist of the present invention is to provide an air battery positive electrode capable of easily diffusing an oxygen-containing gas in the thickness direction, and an air battery capable of increasing capacity and output. .

  The present invention will be described below with reference to the drawings. In addition, the form shown below is an illustration of this invention and this invention is not limited to the form shown below.

1. First Embodiment FIG. 1 is a simplified cross-sectional view showing an air battery 10 of the present invention according to a first embodiment. FIG. 2 is an enlarged cross-sectional view of the air electrode 1 provided in the air battery 10.

  As shown in FIG. 1, the air battery 10 houses the power generation unit 4 including the air electrode 1, the negative electrode 2, and the electrolyte layer 3 disposed between the air electrode 1 and the negative electrode 2. And a housing 5. In the air battery 10, the negative electrode 2 contains a substance that can release or occlude / release metal ions (a simple substance or a compound of metal, hereinafter referred to as “metal”). The separator holding the electrolytic solution is accommodated. Further, the space 6 between the upper surface of the housing 5 and the power generation unit 4 is filled with oxygen-containing gas.

  As shown in FIG. 2, the air electrode 1 includes a first layer 1x having a first support 1a and a composition 1d disposed on the surface thereof, a second support 1b and a composition disposed on the surface thereof. A second layer 1y having 1d, and a third layer 1z having a third support 1c and a composition 1d disposed on the surface thereof, the first support 1a, the second support 1b, and The third support 1c is made of expanded metal. The composition 1d contains a catalyst, a conductive material, and a binder. In the air battery 10 of FIG. 1, the first layer 1x having the first support 1a is disposed on the space 6 side, and the third layer 1z having the third support 1c is disposed on the electrolyte layer 3 side.

  In the air electrode 1, the porosity of the second support 1b is smaller than the porosity of the first support 1a, and the diameter of the hole formed in the second support 1b is formed in the first support 1a. It is smaller than the diameter of the hole. Similarly, in the air electrode 1, the porosity of the third support 1c is smaller than the porosity of the second support 1b, and the diameter of the hole formed in the third support 1c is the same as that of the second support 1b. It is smaller than the diameter of the formed hole. In other words, the air electrode 1 is configured such that the holes become larger from the electrolyte layer 3 toward the space 6. With this configuration, the oxygen-containing gas present in the space 6 can be easily guided in the thickness direction of the air electrode 1. Therefore, to the interface between the conductor (the conductive material contained in the first support 1a, the second support 1b, the third support 1c, and the composition 1d) and the electrolyte in the air electrode 1. As a result, it is possible to increase the performance of the air battery 10. As described above, since the air electrode 1 is configured to easily diffuse the oxygen-containing gas into the air electrode 1, even if the thickness is made thicker than the conventional air electrode, The diffusion of the oxygen-containing gas inside can be ensured. Therefore, for example, when a plurality of air batteries are accommodated in one housing for the purpose of improving performance, the function of the air electrode in each of the plurality of air batteries is made thicker than the conventional air electrode. Even when a plurality of air battery members are shared by concentrating the air electrode 1 in a thick configuration, the air electrode 1 is configured to easily diffuse the oxygen-containing gas. It is possible to suppress a decrease in energy density. Further, since the air electrode 1 is configured such that the holes become larger from the electrolyte layer 3 toward the space 6, it is possible to reduce volatilization of the electrolytic solution filled in the electrolyte layer 3. By reducing the volatilization of the electrolytic solution, it is possible to suppress a decrease in the interface between the conductor, the electrolytic solution, and the oxygen-containing gas, so that the performance of the air battery 10 can be improved. Hereinafter, the air battery 10 will be described for each configuration.

<Air electrode 1>
The air electrode 1 includes a first layer 1x having a first support 1a and a composition 1d disposed on the surface thereof, a second layer 1y having a second support 1b and a composition 1d disposed on the surface thereof. And a third layer 1z having a third support 1c and a composition 1d disposed on the surface of the third support 1c, the composition 1d comprising a conductive material, a catalyst, and a binder for binding them. Contains.

  The metal which comprises the 1st support body 1a, the 2nd support body 1b, and the 3rd support body 1c will not be specifically limited if it can endure the environment at the time of use of the air battery 10. FIG. As the metal constituting the first support 1a, the second support 1b, and the third support 1c, for example, a metal that can constitute a current collector in an air electrode of an air battery can be appropriately used.

  The conductive material contained in the composition 1d is not particularly limited as long as it can withstand the environment when the air battery 10 is used and has conductivity. As such a conductive material, a carbon material having a high specific surface area represented by carbon black, activated carbon, carbon fiber, and the like can be exemplified. Further, from the viewpoint of suppressing a decrease in reaction field and a decrease in battery capacity, the content of the conductive material in the composition 1d is preferably 10% by mass or more. Moreover, from a viewpoint of making it the form which can exhibit a sufficient catalyst function, it is preferable that content of the electroconductive material in the composition 1d shall be 99 mass% or less.

  Examples of the catalyst contained in the composition 1d include inorganic ceramics such as manganese dioxide and cerium dioxide, organic complexes such as cobalt phthalocyanine, and composite materials thereof. From the viewpoint of providing a form capable of exhibiting a sufficient catalytic function, the content of the catalyst in the composition 1d is preferably 1% by mass or more. Further, from the viewpoint of suppressing a decrease in reaction field and a decrease in battery capacity, the content of the catalyst in the composition 1d is preferably 90% by mass or less.

  As the binder contained in the composition 1d, a known binder usable for an air battery, such as polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), and styrene butadiene rubber (SBR), is used. It can be illustrated. The content of the binder in the composition 1d is not particularly limited, but is preferably, for example, 10% by mass or less, and more preferably 1% by mass to 5% by mass.

  The air electrode 1 can be manufactured through the following processes, for example. First, a paste prepared by kneading and kneading a conductive material, a catalyst, and a binder in a solvent is used for each of the first support 1a, the second support 1b, and the third support 1c. The first layer 1x having the first support 1a and the composition 1d disposed on the surface thereof, the second support 1b and the surface thereof are applied by drying using a spray gun. A second layer 1y having the composition 1d and a third layer 1z having the third support 1c and the composition 1d disposed on the surface thereof are prepared. When the first layer 1x, the second layer 1y, and the third layer 1z are each produced in this manner, the air electrode 1 can be produced by successively laminating them. In addition, the first layer 1x and the second layer prepared by thermocompression bonding of the mixed powder containing the conductive material and the catalyst, the first support 1a, the second support 1b, and the third support 1c. The air electrode 1 can also be produced by sequentially laminating 1y and the third layer 1z. Examples of the solvent that can be used in the production of the air electrode 1 include volatile solvents such as acetone, N, N-dimethylformamide (DMF), and N-methyl-2-pyrrolidone (NMP). A solvent having a temperature of 200 ° C. or lower can be preferably used.

<Negative electrode 2>
The negative electrode 2 contains a metal that functions as a negative electrode active material. Further, the negative electrode 2 is provided with a negative electrode current collector (not shown) that contacts the inside or the outer surface of the negative electrode 2 and collects the current of the negative electrode 2.

  Examples of simple metals that can be contained in the negative electrode 2 include Li, Na, K, Mg, Ca, Zn, Al, and Fe. Moreover, Li metal etc. can be illustrated as a metal compound which can be contained in the negative electrode 2. When the air battery 10 is a lithium air secondary battery, it is preferable that Li is contained from the viewpoint of providing the air battery 10 that can easily increase the capacity.

  The negative electrode 2 only needs to contain at least a negative electrode active material, and may further contain a conductive material that improves conductivity, or a binder that fixes a metal or the like. From the viewpoint of suppressing a decrease in reaction field and a decrease in battery capacity, the content of the conductive material in the negative electrode 2 is preferably 10% by mass or less. Further, the content of the binder in the negative electrode 2 is not particularly limited, but is preferably 10% by mass or less, and more preferably 1% by mass or more and 5% by mass or less. The kind of conductive material and binder that can be contained in the negative electrode 2, the amount used, and the like can be the same as in the air electrode 1.

  In the air battery 10, a negative electrode current collector is provided in contact with the inside or the outer surface of the negative electrode 2. The negative electrode current collector has a function of collecting the negative electrode 2. In the air battery 10, the material for the negative electrode current collector is not particularly limited as long as it is a conductive material. Examples of the material for the negative electrode current collector include copper, stainless steel, and nickel. Examples of the shape of the negative electrode current collector include a foil shape, a plate shape, and a mesh (grid) shape. In the air battery 10, the negative electrode 2 can be produced by a method such as applying a paint made of a conductive material, a catalyst, and a binder to the surface of the negative electrode current collector by a doctor blade method. it can. In addition, it can also be produced by a method such as thermocompression bonding of a mixed powder containing a conductive material and a catalyst.

<Electrolyte layer 3>
The electrolyte layer 3 accommodates a separator that holds an electrolyte solution that conducts ions (metal ions) between the air electrode 1 and the negative electrode 2.

The form of the electrolytic solution filled in the electrolyte layer 3 is not particularly limited as long as it has metal ion conductivity, and examples thereof include a nonaqueous electrolytic solution. The type of non-aqueous electrolyte filled in the electrolyte layer 3 is preferably selected as appropriate according to the type of metal ions to be conducted. For example, the non-aqueous electrolyte of a lithium air battery usually contains a lithium salt and an organic solvent. Examples of the lithium salt include LiPF ₆ , LiBF ₄ , LiClO _4, LiAsF _{6 and} other inorganic lithium salts, LiCF ₃ SO ₃ , LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ , LiC An organic lithium salt such as (CF ₃ SO ₂ ) ₃ can be exemplified. Examples of the organic solvent include ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), butylene carbonate, γ-butyrolactone, sulfolane, acetonitrile, 1 , 2-dimethoxymethane, 1,3-dimethoxypropane, diethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, and mixtures thereof. Moreover, it is preferable that an organic solvent is a solvent with high oxygen solubility from a viewpoint of making it the form in which dissolved oxygen is used for reaction efficiently. The concentration of the lithium salt in the non-aqueous electrolyte is, for example, not less than 0.2 mol / L and not more than 3 mol / L. In the air battery of the present invention, a low volatile liquid such as an ionic liquid can be used as the nonaqueous electrolytic solution.

  Moreover, as a separator used for the electrolyte layer 3, in addition to porous membranes, such as polyethylene and a polypropylene, nonwoven fabrics, such as a resin nonwoven fabric and a glass fiber nonwoven fabric, etc. can be illustrated.

<Case 5>
The housing 5 accommodates at least the power generation unit 4 and the oxygen-containing gas. In the air battery 10, the shape of the housing 5 is not particularly limited. As a constituent material of the housing 5, a material that can be used for the housing of the metal-air battery can be appropriately used. Further, as the oxygen-containing gas accommodated in the housing 5 (existing in the space 6), for example, oxygen gas having a pressure of 1.01 × 10 ⁵ Pa and an oxygen concentration of 99.99% can be used.

2. Second Embodiment FIG. 3 is a simplified cross-sectional view showing an air battery 20 of the present invention according to a second embodiment. FIG. 4 is an enlarged cross-sectional view showing the air electrode 11 provided in the air battery 20. 3, components having the same configuration as that of the air battery 10 are denoted by the same reference numerals as those used in FIG. 1, and description thereof is omitted as appropriate. Also, in FIG. 4, the same reference numerals as those used in FIG. 2 are assigned to components having the same configuration as the air electrode 1, and the description thereof is omitted as appropriate.

  As shown in FIG. 3, the air battery 20 is configured similarly to the air battery 10 except that an air electrode 11 is provided instead of the air electrode 1 of the air battery 10, and the air electrode 11, the negative electrode 2, and the air A power generation unit 12 including the electrolyte layer 3 disposed between the electrode 11 and the negative electrode 2 and a housing 5 that houses the power generation unit 12 are provided. As shown in FIG. 4, the air electrode 11 includes a first support 1a and a first layer 1x having a composition 1d disposed on the surface thereof, a second support 1b and a composition disposed on the surface thereof. A second layer 1y having 1d, and a third layer 1z having a third support 1c and a composition 1d disposed on the surface thereof. In the air battery 20 of FIG. 3, the air electrode 11 in which the third layer 1z having the third support 1c is disposed on the space 6 side and the first layer 1x having the first support 1a is disposed on the electrolyte layer 3 side. It has.

  In the air electrode 11, the porosity of the second support 1b is larger than the porosity of the third support 1c, and the diameter of the hole formed in the second support 1b is formed in the third support 1c. It is larger than the diameter of the hole. Similarly, in the air electrode 11, the porosity of the first support 1a is larger than the porosity of the second support 1b, and the diameter of the hole formed in the first support 1a is the same as that of the second support 1b. It is larger than the diameter of the formed hole. That is, the air electrode 11 is configured such that the holes become smaller from the electrolyte layer 3 toward the space 6. By adopting a configuration in which the small holes are arranged on the space 6 side, the air electrode 11 having improved water repellency compared to the air electrode 1 can be obtained. As a result, the moisture contained in the oxygen-containing gas in the space 6 However, it is difficult to move to the electrolyte layer 3 side. Furthermore, by setting it as such a form, it becomes possible to move the water | moisture content which has reached the electrolyte layer 3 side to the space 6 side by capillary action. Thus, according to the air battery 20 provided with the air electrode 11, it is possible to make it difficult for moisture to be present in the electrolyte layer 3. By making the electrolyte layer 3 into a form in which moisture is unlikely to exist, the reaction between the metal contained in the negative electrode 2 and water can be reduced, so that deterioration / abnormality / runaway of the battery can be suppressed. The air battery 20 can be provided.

  In the above description regarding the air electrodes 1 and 11 of the present invention and the air batteries 10 and 20 of the present invention, the air electrode 1 configured so that the holes gradually increase from the electrolyte layer 3 toward the space 6, or Although the air electrode 11 configured such that the pores gradually become smaller from the electrolyte layer 3 toward the space 6 is illustrated, the present invention is not limited to this form. The positive electrode for an air battery according to the present invention can be configured such that a support having relatively small holes is laminated between two supports having relatively large holes. In addition, a support body in which relatively large holes are formed may be laminated between two support bodies in which relatively small holes are formed.

  Moreover, in the said description regarding the air electrodes 1 and 11 of this invention, and the air batteries 10 and 20 of this invention, the air electrode 1 and the air electrode 11 are provided with three support bodies (a 1st support body 1a and a 2nd support body). Although 1b and the form with which the 3rd support body 1c) is provided were illustrated, this invention is not limited to the said form. The number of supports provided in the positive electrode for an air battery of the present invention is not particularly limited as long as it is 2 or more.

  Moreover, in the said description regarding the air electrodes 1 and 11 of this invention, and the air batteries 10 and 20 of this invention, the 1st support body 1a comprised by an expanded metal, the 2nd support body 1b, and the 3rd support body. Although the form with which 1c is provided was illustrated, this invention is not limited to the said form. When the positive electrode for an air battery of the present invention is provided with a support composed of a conductive material, the form of the support is not particularly limited as long as it has a hole. For example, metal or carbon Forms, such as a fibrous member, a nonwoven fabric, and a foaming material comprised by material, can be taken. Among these, it is preferable to use a support made of carbon paper or a metal mesh. From the viewpoint of easily controlling the size and distribution of holes, a metal mesh (for example, expanded metal or punching metal) is preferable. It is more preferable to use a support constituted by, for example. Moreover, the support body provided in the positive electrode for air batteries of this invention may be comprised with the insulating material. However, from the viewpoint of making it possible to provide a high-performance positive electrode for an air battery and an air battery by improving the electronic conductivity, it is preferable that the support is made of a conductive material.

  Moreover, in the said description regarding the air batteries 10 and 20 of this invention, although the form with which the electrolyte layer 3 in which the separator holding electrolyte solution was accommodated was illustrated, the air battery of this invention is limited to the said form is not. The electrolyte layer in the air battery of the present invention is filled with a polymer electrolyte such as LiTFSI-PEO (including gel polymer electrolyte) or a solid electrolyte such as Li-La-Ti-O. Is also possible.

  In the above description regarding the air batteries 10 and 20 of the present invention, the power generation unit 4 and the atmosphere are separated from each other by the upper surface of the housing 5 and the power generation unit 4 is not open to the atmosphere. The air battery is not limited to this form. The casing of the air battery of the present invention can be configured such that an upper lid is not provided. However, when the electrolytic solution is filled between the air electrode and the negative electrode, the power generation unit may not be open to the atmosphere from the viewpoint of a configuration that can suppress depletion of the electrolytic solution. preferable.

  The present invention will be further described below with reference to examples.

  A cell simulating the air battery of the present invention was produced, and the structure of the air electrode (the structure of the second layer) was observed.

1) Production of Evaluation Cell A cell of the present invention was produced using the materials shown below. Specifically, the cell of the present invention was produced by installing an electrochemical cell in a sealed glass desiccator with a gas replacement cock. The inside of the sealed glass desiccator was a pure oxygen atmosphere.
・ Air electrode: Carbon black, manganese dioxide catalyst, and PVDF binder were weighed to a mass ratio of 25:42:33, and then put into an acetone solvent and kneaded and stirred to obtain a paste-like composition. A product was made. Next, the prepared composition was applied to the surface of three supports (Ni expanded metal, manufactured by Taiyo Wire Mesh Co., Ltd.) using a spray gun and dried, whereby the first layer, the second layer, and A third layer was produced. And the air electrode (positive electrode for air batteries) was produced by laminating | stacking a 1st layer, a 2nd layer, and a 3rd layer in order. Here, the hole diameter of the first layer support was 1.53 mm, the hole diameter of the second layer support was 1.09 mm, and the hole diameter of the third layer support was 0.77 mm. .
・ Negative electrode: Li (made by Honjo Metal Co., Ltd.)
Electrolyte: non-aqueous electrolyte (made by Kishida Chemical Co., Ltd.) in which LiClO ₄ is dissolved in propylene carbonate at a concentration of 1 mol / L
・ Atmosphere: Pure oxygen (99.99%, 1 atm)
・ Cell: Electrochemical cell made by Hokuto Denko Co., Ltd.

2) Microscope observation The produced 2nd layer was observed using the scanning electron microscope (S4500, Hitachi High-Technologies Corporation make). The results are shown in FIG. As shown in FIG. 5, the shape of the hole formed in the support was a rhombus, and the paste-like composition was applied on the Ni expanded metal.

  The air battery of the present invention can be used as a power source for electric vehicles and portable information devices.

1 ... Air electrode (positive electrode for air battery)
DESCRIPTION OF SYMBOLS 1a ... 1st support body 1b ... 2nd support body 1c ... 3rd support body 1d ... Composition 1x ... 1st layer 1y ... 2nd layer 1z ... 3rd layer 2 ... Negative electrode 3 ... Electrolyte layer 4 ... Power generation part 5 ... Case 6 ... Space 10 ... Air battery 11 ... Air electrode (positive electrode for air battery)
12 ... Power generation unit 20 ... Air battery

Claims (3)

A first layer having a first support having holes and a catalyst supported on the first support, a second support having holes, and a second layer having a catalyst supported on the second support. At least a positive electrode for an air battery,
The first layer and the second layer are laminated,
The positive electrode for an air battery, wherein a diameter of the hole provided in the first support is different from a diameter of the hole provided in the second support. The positive electrode for an air battery according to claim 1, wherein the first support and / or the second support is made of metal. An air battery comprising a negative electrode, a positive electrode supplied with an oxygen-containing gas, and an electrolyte solution that conducts ions between the negative electrode and the positive electrode,
The positive electrode is a positive electrode for an air battery according to claim 1 or 2,
The second layer is disposed between the first layer and the electrolyte;
An air battery characterized in that a diameter of the hole provided in the second support is smaller than a diameter of the hole provided in the first support.