JP5692866B2 - Air battery - Google Patents

Description

  The present invention relates to an air battery.

An air battery is a battery that uses oxygen in the air as a positive electrode active material.
Since oxygen in the air can be used as the positive electrode active material, most of the air battery body can be constituted by the negative electrode. Therefore, there is an advantage that a battery having a high energy density can be obtained as compared with other batteries.

On the other hand, the negative electrode active material of an air battery is generally zinc or an aluminum alloy, and these generate a metal oxide or a metal hydroxide by a discharge reaction. In particular, it is known that an aluminum air battery using an aluminum alloy as a negative electrode has a high energy density.
In addition, as an electrolytic solution of a conventional aluminum air battery, a neutral aqueous solution in which an electrolyte such as sodium chloride (NaCl), aluminum chloride (AlCl ₃ ), manganese chloride (II) (MnCl ₂ ) is dissolved in water, or water An alkaline aqueous solution in which an electrolyte such as sodium oxide (NaOH) or potassium hydroxide (KOH) is dissolved in water is used.

However, when a neutral aqueous solution is used as the electrolytic solution, the oxide film on the aluminum electrode is insoluble in the neutral aqueous solution, so that it operates under a load and the operating voltage and current efficiency are low. was there.
On the other hand, when an alkaline aqueous solution is used as the electrolyte, although the operating voltage and current efficiency are high, there is a problem that the corrosion of the aluminum alloy (so-called self-corrosion), that is, self-discharge is large when the battery is unloaded. there were.

  Therefore, as an air battery that solves the above problems when an alkaline aqueous solution is used as an electrolytic solution, an air battery having a configuration in which an aluminum block as a negative electrode is continuously replenished from the replenishment port to the battery body is disclosed ( Non-patent document 1). In this air battery, the replenished aluminum block is supported by a point contact or a line contact in the electrolyte solution by the protruding portion of the negative electrode current collector, and is opened to the atmosphere via the replenishment port (Non-Patent Document). 1 (see FIG. 3-7-4).

Yoshiharu Matsuda et al., “Battery Handbook”, published by Maruzen Co., Ltd., August 20, 1990, p. 313-315

  However, in the air battery described in Non-Patent Document 1, the aluminum block proceeds with a dissolution reaction on the surface in contact with the electrolytic solution, but the dissolution reaction at the contact portion between the aluminum block and the negative electrode current collector is more preferential. Therefore, the replenished aluminum block falls off in the main body, and the utilization factor of the negative electrode is lowered.

  An object of the present invention is to provide an air battery in which a negative electrode is prevented from falling off in a main body even when an alkaline aqueous solution is used as an electrolytic solution.

The present invention includes a positive electrode including a positive electrode catalyst, a negative electrode, and a main body provided with a diffusion member having a surface that supports the negative electrode, an air supply port for supplying air to the positive electrode, an electrolyte, and the main body. And a circulating means for circulating the electrolyte solution, wherein the negative electrode can be continuously replenished to the main body from a negative electrode replenishment port, and the electrolyte solution passes through the interior of the diffusion member. It passes, the negative electrode, to provide an air battery, which is reachable in supported surface to the top surface of the diffusion member.
In the air battery, it is preferable that the diffusion member is made of a porous insulating material that does not react with the electrolytic solution.
In the air battery, the porous insulating material is preferably zirconia.
The air battery is preferably provided with a shielding structure in which the electrolytic solution in the main body is shielded from the outside on the negative electrode supply port side.
In the air battery, it is preferable that the shielding structure has a first packing in which a gap between the negative electrode and the main body is sealed in the main body.
In the air battery, it is preferable that the first packing is further disposed in contact with the diffusion member.
In the air battery, it is preferable that the shielding structure further includes a second packing that seals between the negative electrode and the main body within the main body.
In the air battery, it is preferable that a gas or a liquid that does not react with the negative electrode is sealed in a gap between the first packing and the second packing.
In the air battery, it is preferable that one or both of the first packing and the second packing are O-shaped.
In the air battery, the negative electrode is preferably prismatic or cylindrical.
In the air battery, the negative electrode is preferably made of aluminum or an aluminum alloy.
In the air battery, the negative electrode is preferably made of an aluminum alloy, and the aluminum alloy preferably satisfies the following conditions:
Magnesium content is 0.0001-8 mass%,
Satisfy at least one of the following (a) and (b),
(A) Iron content is 0.0001-0.03 mass%
(B) Content of silicon is 0.0001-0.02 mass%
And content of elements other than aluminum, magnesium, silicon, and iron is 0.005 mass% or less, respectively.
In the air battery, the total content of elements other than aluminum and magnesium in the aluminum alloy is preferably 0.1% by mass or less.
In the air battery, the negative electrode is made of an aluminum alloy, the aluminum alloy includes intermetallic compound particles in an alloy matrix, and the surface area of the intermetallic compound particles observed on the surface of the alloy is 0. The density of particles of 1 μm ² or more and less than 100 μm ² is 1000 particles / mm ² or less, the density of particles of 100 μm ² or more is 10 particles / mm ² or less, and between the metals per unit surface area of the alloy The area occupied by the compound particles is preferably 0.5% or less.
In the air battery, the electrolytic solution is preferably an aqueous solution containing one or more electrolytes selected from the group consisting of potassium hydroxide, sodium hydroxide, lithium hydroxide, barium hydroxide, and magnesium hydroxide.
In the air battery, the positive electrode catalyst preferably contains manganese dioxide or platinum.
In the air battery, the positive electrode catalyst preferably contains a perovskite complex oxide represented by a general formula “ABO ₃ ”, and A is two or more elements selected from the group consisting of lanthanum, strontium, and calcium B preferably contains one or more elements selected from the group consisting of manganese, iron, chromium and cobalt.
In the air battery, it is preferable that an oxygen selective permeable membrane is provided that allows oxygen to permeate the air supplied from the air supply port to reach the positive electrode.
In the air battery, it is preferable that a contact angle of the electrolytic solution with respect to the surface of the oxygen selective permeable membrane is 90 ° or more.
In the air battery, the contact angle is preferably 150 ° or more.
In the air battery, it is preferable that the oxygen selective coefficient of the oxygen selective permeable membrane is 400 × 10 ⁻¹⁰ cm ³ · cm ² / s ² · cm · Hg or more.
In the air battery, the oxygen / carbon dioxide selective permeability of the oxygen selective permeable membrane is preferably 0.15 or more.

  ADVANTAGE OF THE INVENTION According to this invention, even when alkaline aqueous solution is used as electrolyte solution, the air battery by which the drop-off of the negative electrode in a main body was prevented can be provided.

1 is a schematic configuration diagram illustrating a first embodiment of an air battery according to the present invention. It is an expanded sectional view of the positive electrode in the air battery shown in FIG. It is a front view which illustrates the structure of the positive electrode in the air battery shown in FIG. It is a schematic sectional drawing which illustrates the main-body part in 2nd embodiment of the air battery which concerns on this invention. It is a schematic sectional drawing which illustrates the main-body part in 3rd embodiment of the air battery which concerns on this invention. It is a schematic sectional drawing which illustrates the main-body part in 4th embodiment of the air battery which concerns on this invention.

Hereinafter, the present invention will be described in detail.
FIG. 1 is a schematic configuration diagram illustrating a first embodiment of an air battery according to the present invention.
The air battery 1 shown here includes a main body 2A, an electrolytic solution 3, a reservoir 4 filled with the electrolytic solution 3, a liquid feeding means 5 for feeding the electrolytic solution 3, and a pipe 6. The main body 2A, the reservoir 4 and the liquid feeding means 5 are connected to each other by a pipe 6, and the electrolytic solution 3 can be continuously supplied (circulated) to the main body 2A when the liquid feeding means 5 is operated. . That is, the storage unit 4, the liquid supply unit 5, and the pipe 6 function as a circulation unit for circulating the electrolyte solution 3 through the main body 2 </ b> A in the air battery 1. In FIG. 1, only a part of the main body 2A is shown in cross section for easy understanding.

  The main body 2A is provided with a positive electrode 21 including a positive electrode catalyst, a negative electrode 22, an air supply port 201 for supplying air to the positive electrode 21, and a diffusion member 23 having a surface for supporting the negative electrode 22. The air supply port 201, the positive electrode 21, the diffusion member 23, and the negative electrode 22 are arranged in this order from the bottom to the top.

The negative electrode 22 preferably has a columnar shape such as a columnar shape, an elliptical columnar shape, or a prismatic shape.
The negative electrode 22 is inserted into the main body 2A from the negative electrode replenishment port 202 opened at the top of the main body 2A, guided by the convex portion of the inner surface 203 of the main body 2A, and the upper surface 23a of the diffusion member 23. Is supported on the bottom surface 22a. Thus, the negative electrode 22 is detachably disposed in the main body 2A. Further, one end of the negative electrode lead 24 is disposed in contact with the surface of the negative electrode 22 located outside the negative electrode supply port 202, and the other end is fixed to the upper surface of the main body 2 </ b> A by a screw 25. The method for fixing the negative electrode lead 24 may be a method other than the screw fastening shown here.

  FIG. 2 is an enlarged cross-sectional view of the positive electrode 21. As shown here, the positive electrode 21 is formed by laminating a mesh-shaped positive electrode current collector 21a having a large number of through holes, a positive electrode catalyst layer 21b, and a porous hydrophobic film 21c in this order. Further, in the positive electrode 21 shown here, the laminate is sandwiched between two ring-shaped rubber plates 21d and 21d having openings. The positive electrode 21 is disposed such that the hydrophobic film 21c faces the direction of the air supply port 201, that is, the outside of the main body 2A (the lower side in FIG. 1). Therefore, the diffusion member 23 is disposed in contact with the surface near the inner peripheral portion of the rubber plate 21d below the positive electrode 21 in FIG. The positive electrode current collector 21a is connected to an external connection terminal 21e made of a metal such as nickel.

  FIG. 3 is a front view illustrating the configuration of the positive electrode 21. FIG. 3A is a front view illustrating a first stacked body 210a in which the positive electrode catalyst layer 21b is formed on the positive electrode current collector 21a. FIG. 3B shows a second example in which a hydrophobic membrane 21c is laminated on the positive electrode current collector 21a of the first laminate 210a of FIG. 3A so as to cover the positive electrode catalyst layer 21b. It is a front view which illustrates the laminated body 210b of. FIG. 3C is a front view illustrating the positive electrode 21 formed by sandwiching the second laminated body 210b of FIG. 3B between two rubber plates 21d and 21d. As described above, the positive electrode 21 can be manufactured by laminating each layer and sandwiching the layers between the two rubber plates 21d and 21d.

Two first nozzles 261 and 261 for supplying and collecting the electrolytic solution 3 to and circulate the electrolytic solution 3 with respect to the diffusion member 23 arranged inside are provided on the side surface of the main body 2A. Yes. That is, the main body 2 </ b> A is connected to the reservoir 4 and the liquid feeding means 5 by the pipe 6 through the first nozzles 261 and 261.
In addition, two second nozzles 262 and 262 are provided on the side surface of the main body 2A so as to be connected to an arrangement site of the internal negative electrode 22. By opening or closing these second nozzles 262, 262, the inside of the main body 2A can be adjusted so as to be opened or closed with respect to the outside. At the time of opening, for example, the inside of the main body 2A can be cleaned by supplying a cleaning liquid from the outside via the second nozzle 262. Further, when the electrolyte solution 3 is circulated, the electrolyte solution 3 can be prevented from leaking to the arrangement site of the anode 22 by applying pressure from the outside via the second nozzle 262.

The positive electrode current collector 21a, the positive electrode catalyst layer 21b, and the hydrophobic film 21c may all be known materials.
A preferable example of the positive electrode current collector 21a is an alloy material such as stainless steel.
As a preferable positive electrode catalyst layer 21b, a conductive material such as acetylene black, an oxygen reduction catalyst (positive electrode catalyst) such as manganese dioxide (MnO ₂ ) or platinum (Pt), and a binder such as polytetrafluoroethylene (PTFE). The material containing these can be illustrated. Moreover, the material containing the perovskite type complex oxide represented by the general formula “ABO ₃ ” can be exemplified as the positive electrode catalyst. Such a complex oxide contains two or more elements selected from the group consisting of lanthanum, strontium and calcium at the A site, and one or more elements selected from the group consisting of manganese, iron, chromium and cobalt at the B site. .

  As a preferable hydrophobic membrane 21c, a porous membrane made of a fluororesin such as polyvinylidene fluoride can be exemplified. By providing the hydrophobic film 21c, the leakage of the electrolyte solution 3 from the air supply port 201 is further suppressed.

The diffusion member 23 is a plate-like member whose upper surface 23 a is a surface (support surface) that supports the negative electrode 22. However, the shape is not limited thereto, and other shapes such as a block shape may be used as long as the support surface of the negative electrode 22 is provided.
The diffusing member 23 has a structure such as a porous body that allows the electrolytic solution 3 to pass therethrough, and the material thereof may be any material that has insulating properties and does not react with the electrolytic solution 3, and preferably zirconia. (Zirconium dioxide, ZrO ₂ ) can be exemplified.
The porosity of the diffusing member 23 is not particularly limited, but is preferably 30 to 70% in order to efficiently generate turbulent flow in the electrolyte solution 3 as described later without impairing the strength. As a lower limit of porosity, 35% or more is more preferable, and 40% or more is more preferable. The upper limit value of the porosity is more preferably 65% or less, and further preferably 60% or less.
The size of the diffusing member 23 may be adjusted as appropriate in consideration of the size of the negative electrode 22 and the amount of the electrolyte 3 supplied. For example, the thickness may be ² to 8 mm when the area of the bottom surface 22 a (the surface supported by the diffusion member 23) that is a contact surface with the diffusion member 23 of the negative electrode 22 is 20 to 180 mm 2. preferable. The thickness is more preferably 3 mm or more, and further preferably 4 mm or more. The thickness is more preferably 7 mm or less, and further preferably 6 mm or less. The area of the upper surface 23 a is preferably 2 to 6 times the area of the bottom surface 22 a of the negative electrode 22. The lower limit of the area of the upper surface 23a with respect to the area of the bottom surface 22a of the negative electrode 22 is more preferably three times or more. Moreover, as an upper limit, it is more preferable that it is 5 times or less, and it is further more preferable that it is 4 times or less.

  The negative electrode 22 may be a known material, and examples thereof include aluminum, zinc, iron, and any alloy thereof. Of these, aluminum or an aluminum alloy is preferable because of its excellent power generation performance.

The aluminum alloy preferably has (i) a magnesium content of 0.0001 to 8% by mass. Further, (ii) the aluminum alloy preferably satisfies at least one of the following (a) and (b):
(A) Iron content is 0.0001-0.03 mass%
(B) Silicon content is 0.0001-0.02 mass%.
Moreover, (iii) It is preferable that content of elements other than aluminum, magnesium, silicon, and iron is 0.005 mass% or less, respectively.
In this invention, it is preferable that the said aluminum alloy satisfy | fills any one or more of said (i)-(iii), and it is more preferable to satisfy | fill all said (i)-(iii). When all of the above (i) to (iii) are satisfied, the aluminum alloy further preferably has a total content of elements other than aluminum and magnesium of 0.1% by mass or less, and 0.05% by mass. More preferably, it is more preferably 0.01% by mass or less. As a lower limit, 0.0001 mass% or more is preferable. The content of each element in the aluminum alloy can be measured by, for example, an emission spectroscopic analyzer, a glow discharge mass spectrometer or the like.
The magnesium content is more preferably 0.001% by mass or more, and further preferably 0.005% by mass or more. The magnesium content is more preferably 7% by mass or less, and further preferably 5% by mass or less.
The iron content is more preferably 0.0005% by mass or more, and further preferably 0.001% by mass or more. The iron content is more preferably 0.02% by mass or less, and further preferably 0.01% by mass or less.
The silicon content is more preferably 0.0005% by mass or more, and further preferably 0.001% by mass or more. The silicon content is more preferably 0.01% by mass or less, and further preferably 0.005% by mass or less.
The content of elements other than aluminum, magnesium, silicon and iron is more preferably 0.002% by mass or less, and further preferably 0.001% by mass or less. Moreover, 0 mass% may be sufficient as content of elements other than the said aluminum, magnesium, silicon, and iron, respectively.

The aluminum alloy preferably includes intermetallic particles in an alloy matrix. In this case, among the intermetallic compound particles observed on the alloy surface, (iv) the density of particles having a surface area of 0.1 μm ² or more and less than 100 μm ² is preferably 1000 particles / mm ² or less, (v) The density of particles of 100 μm ² or more is preferably 10 / mm ² or less. The surface area of the intermetallic compound particles can be calculated, for example, by observing the particles with an electron microscope or the like. The density of the intermetallic compound particles can be calculated, for example, by measuring the number of target particles on the alloy surface with an electron microscope or the like.
Moreover, (vi) The area occupied by the intermetallic compound particles per unit surface area of the alloy is preferably 0.5% or less. The area occupied by the intermetallic compound particles on the surface of the alloy can be measured, for example, by observing the surface of the alloy with an electron microscope or the like.
In the present invention, the aluminum alloy preferably satisfies any one of the above (iv) to (vi), and more preferably satisfies all the above (iv) to (vi).
Of the intermetallic compound particles, the density of the particles having a surface area of 0.1 μm ² or more and less than 100 μm ² is more preferably 800 particles / mm ² or less, and still more preferably 700 particles / mm ² or less. . The density of particles having a surface area of 0.1 μm ² or more and less than 100 μm ² may be 0 / mm ² .
Among the intermetallic compound particles, the density of particles having a surface area of 100 μm ² or more is more preferably 7 particles / mm ² or less, and further preferably 5 particles / mm ² or less. The density of the particles having a surface area of 100 μm ² or more may be 0 / mm ² .
The occupied area of the intermetallic compound particles per unit surface area of the alloy is more preferably 0.3% or less, and further preferably 0.1% or less. The occupied area of the intermetallic compound particles per unit surface area of the alloy is preferably 0.001% or more.

  In the main body 2A, the material of the portion other than the above-described members (hereinafter referred to as “exterior material”) such as the positive electrode 21, the negative electrode 22, and the diffusion member 23 is, for example, a material that does not react with the electrolytic solution 3, etc. Any material that does not interfere with the effects of the present invention is not particularly limited. Examples of preferable materials include various resins such as polyether ether ketone (PEEK).

The electrolyte solution 3 may be a known material, for example, either a neutral aqueous solution or an alkaline aqueous solution.
Examples of the neutral aqueous solution include aqueous solutions containing electrolytes such as sodium chloride (NaCl), aluminum chloride (AlCl ₃ ), and manganese (II) chloride (MnCl ₂ ).
Examples of the alkaline aqueous solution include potassium hydroxide (KOH), sodium hydroxide (NaOH), lithium hydroxide (LiOH), barium hydroxide (Ba (OH) ₂ ), magnesium hydroxide (Mg (OH) ₂ ), and the like. An aqueous solution containing an electrolyte can be exemplified.
The electrolyte of the electrolytic solution 3 may be one type or two or more types. In the case of two or more types, the combination and ratio can be arbitrarily selected.

The storage part 4 should just be comprised from the material which does not react with the electrolyte solution 3, and can illustrate the containers made from various resin, such as a polypropylene, as a preferable material.
The liquid feeding means 5 may be any means capable of feeding a liquid, and a normal liquid feeding pump can be used.
The pipe 6 only needs to be made of a material that does not react with the electrolytic solution 3, and may be the same material as the reservoir 4.

  The air battery 1 operates as follows. That is, when the liquid feeding means 5 is operated with the negative electrode 22 inserted into the main body 2A, the electrolytic solution 3 is fed in the pipe 6 in the direction indicated by the arrow in the figure. As a result, the electrolytic solution 3 is supplied to the diffusing member 23 disposed inside the main body 2 </ b> A via the first nozzle 261 on the upstream side (side closer to the liquid feeding means 5). The electrolytic solution 3 penetrates into the plate-like diffusion member 23 from the side surface, passes through the surface, and is supported by the diffusion member 23 of the negative electrode 22 (bottom surface 22a), and in some cases. It reaches the side surface in the vicinity and contacts the negative electrode 22. Further, the electrolytic solution 3 is also in contact with the positive electrode 21. At this time, turbulent flow of the electrolytic solution 3 easily occurs inside the diffusion member 23 that is a porous body, and as a result, the product generated by the discharge is smoothly removed without adhering to the negative electrode 22, and the negative electrode 22. And the electrolytic solution 3 are presumed to contact efficiently. As a result, it is possible to obtain a power generation performance superior to that of the prior art. The electrolytic solution 3 that has passed through the diffusion member 23 is discharged from the first nozzle 261 on the downstream side (the side far from the liquid feeding means 5) to the outside of the main body 2A, and is collected in the storage unit 4 through the pipe 6. It is supplied again to the main body 2A and circulates.

  Due to the power generation, the negative electrode 22 is consumed from the site (lower side) on the diffusion member 23 side, and the length in the longitudinal direction gradually decreases. However, the new negative electrode 22 is separately provided from the negative electrode supply port 202 through the main body 2A. It can be replenished continuously by inserting it into the interior of the battery, enabling continuous power generation. At this time, the negative electrode 22 is guided by the convex portion of the inner surface 203 of the main body 2A and is supported by surface contact by the upper surface 23a of the diffusion member 23, so that the negative electrode 22 is stably held inside the main body 2A. Is prevented from falling off.

  Here, the air battery in which the porous hydrophobic film 21c is provided on the positive electrode catalyst layer 21b has been described as the positive electrode 21, but the hydrophobic film 21c may not be provided. Further, instead of the hydrophobic film 21c, a film having different characteristics may be provided. Furthermore, two or more films may be laminated instead of one film. Examples of the membrane other than the hydrophobic membrane include an oxygen selective permeable membrane. Even when an oxygen selective permeable membrane is provided in place of the hydrophobic membrane 21c, the positive electrode 21 is arranged so that the oxygen selective permeable membrane faces the outside (lower side in FIG. 1) of the main body 2A.

As described above, the oxygen selective permeable membrane is provided between the air replenishment port 201 and the positive electrode catalyst layer 21b in the main body 2A, so that the air replenished from the air replenishment port 201 into the main body 2A. Of these, oxygen selectively permeates through this membrane. Therefore, mixing of carbon dioxide into the electrolytic solution 3 in the main body 2A is suppressed. Thereby, especially when alkaline aqueous solution is used as the electrolyte solution 3, the neutralization of the electrolyte solution 3 by the mixed carbon dioxide is suppressed, and a quality change can be suppressed. Further, poisoning of the positive electrode catalyst by carbon dioxide is suppressed. As a result, the power generation performance is further improved.
The material for the oxygen selective permeable membrane may be a known material, and is not particularly limited, but as a preferable material, an organosilicon compound having a siloxane bond such as silicone as a main skeleton can be exemplified.

The oxygen selective permeable membrane is preferably a membrane having an oxygen selectivity coefficient (PO ₂ ) of 400 × 10 ⁻¹⁰ cm ³ · cm / cm ² · s · cm Hg or more, preferably 500 × 10 ⁻¹⁰ cm ³ · cm / cm. ^A film having ² · s · cmHg or more is more preferable, and a film having 600 × 10 ⁻¹⁰ cm ³ · cm / cm ² · s · cmHg or more is more preferable. A film having an oxygen selectivity coefficient (PO ₂ ) of 1000 × 10 ⁻¹⁰ cm ³ · cm / cm ² · s · cm Hg or less is preferable. The oxygen selective permeable membrane is preferably a membrane having an oxygen / carbon dioxide selective permeability of 0.15 or more, more preferably 0.16 or more, and even more preferably 0.19 or more. A membrane having oxygen / carbon dioxide selective permeability of 0.80 or less is preferable. By using such an oxygen selective permeable membrane, the oxygen selectivity is further improved and the carbon dioxide shielding ability is further improved, so that the power generation performance is further improved.

  The oxygen selective permeable membrane is preferably a membrane having a contact angle of the electrolytic solution 3 with respect to the surface of 90 ° or more, and more preferably a membrane having 150 ° or more. The contact angle may be 180 ° C. By selecting such a film, not only selectively permeating oxygen but also having water repellency, the leakage of the electrolytic solution 3 from the air supply port 201 is further suppressed.

Various configurations other than those shown here can be used as the main body in the air battery 1.
FIG. 4 is a schematic cross-sectional view illustrating the main body portion in the second embodiment of the air battery according to the invention.
The main body 2B shown here has an O-shaped (ring-shaped) first packing 271 having an opening in the main body 2A shown in FIG. The structure between the negative electrode 22 and the inner surface 203 of the main body is sealed. The “O-shape” refers to the shape of the first packing 271 when viewed in plan so as to look down on the opening. The flatness calculated from the long radius and the short radius is a deviation of about −5 ° to 5 °. The deviation is preferably -3 ° to 3 °, more preferably -1 ° to 1 °.
Here, the gap provided in the upper part of the diffusing member 23 along the outer peripheral surface of the negative electrode 22 and having the first packing 271 mounted thereon is referred to as a first gap and is denoted by reference numeral 204A. Except for this point, the main body 2B is the same as the main body 2A shown in FIG. The air battery according to the second embodiment is the same as the air battery 1 except that a main body 2B is provided instead of the main body 2A.

  Thus, by providing a shielding structure that shields the inside of the main body from the outside on the negative electrode supply port 202 side with respect to the diffusing member 23, the electrolytic solution 3 in the main body 2B is shielded from the outside. As a result, foreign matter and gas are prevented from being mixed into the electrolytic solution 3 from the negative electrode supply port 202, and the electrolytic solution 3 can be maintained with good quality. For example, since the mixing of carbon dioxide in the air into the electrolytic solution 3 is suppressed, the quality change of the electrolytic solution 3 can be suppressed. Further, leakage of the electrolyte 3 from the negative electrode replenishment port 202 can be suppressed without strictly managing the supply pressure of the electrolyte 3 during circulation.

  The material of the first packing 271 may be, for example, a material that does not react with the electrolytic solution 3, and is preferably an ethylene propylene rubber such as EPM or EPDM; a fluorine rubber such as propylene hexafluoride-vinylidene fluoride copolymer Can be illustrated.

FIG. 5 is a schematic cross-sectional view illustrating the main body portion in the third embodiment of the air battery according to the present invention.
The main body 2 </ b> C shown here is different from the main body 2 </ b> B shown in FIG. 4 in that the shape of the first gap 204 </ b> A is different and the first packing 271 is further disposed in contact with the diffusion member 23. Here, an example is shown in which the lower portion of the first packing 271 is in close contact with the upper surface 23 a of the diffusion member 23. As shown in the enlarged sectional view, the first packing 271 is in close contact with the lowermost part 22b in the vicinity of the diffusing member 23 in the outer peripheral surface of the negative electrode 22, and the electrolyte solution 3 is in contact with this part. It is suppressed. As a result, the electrolyte solution 3 comes into contact with only the bottom surface 22a (the surface supported by the diffusion member 23) of the negative electrode 22, and discharge occurs only at the bottom surface 22a. In addition, the shape of the negative electrode 22 in use can be held more stably.
The air battery of the third embodiment is the same as the air battery 1 except that a main body 2C is provided instead of the main body 2A.

FIG. 6 is a schematic cross-sectional view illustrating the main body portion in the fourth embodiment of the air battery according to the invention.
In the main body 2D shown in FIG. 5, in addition to the first packing 271, the second packing 272, which is an O-shaped ring, is mounted inside the main body 2C shown in FIG. The packing 272 has a configuration in which the space between the negative electrode 22 and the inner surface 203 of the main body portion is sealed. Here, along the outer peripheral surface of the negative electrode 22, the gap provided in the upper part of the first gap 204 </ b> A and fitted with the second packing 272 is referred to as a second gap and is denoted by reference numeral 204 </ b> B.
The second packing 272 is the same material as the first packing 271, and may be the same as or different from the first packing 271.

Since the main body 2D is provided with the second packing 272, the shielding effect from the outside of the electrolytic solution 3 in the main body 2D is further improved. Further, a gap 205 is formed between the first packing 271 and the second packing 272. The gap portion 205 becomes a sealed space when the second nozzle 262 connected thereto is closed. Therefore, by supplying a gas or a liquid that does not react with the negative electrode 22 from the second nozzle 262 to the gap portion 205, the gap portion 205 can be filled with the gas or the liquid, and the shielding effect from the outside of the electrolytic solution 3 can be obtained. Is further improved. In particular, a more excellent effect can be obtained by supplying gas to bring the gap 205 into a pressurized state.
The air battery of the fourth embodiment is the same as the air battery 1 except that a main body 2D is provided instead of the main body 2A.

  The air battery provided with the main body 2B, 2C, or 2D operates in the same manner as the air battery 1 provided with the main body 2A, and generates power.

  The air battery according to the present invention is not limited to the configuration described so far, and a part of the configuration may be changed within a range that does not significantly disturb the effect of the present invention. For example, as a main-body part, the structure by which the flow path of the electrolyte solution 3 was set so that the electrolyte solution 3 may infiltrate into the inside from the side surface with respect to the diffusion member 23 in FIGS. However, for example, the electrolytic solution 3 may enter the inside from the lower surface of the diffusion member 23 (the surface opposite to the upper surface 23 a supporting the negative electrode 22). For this purpose, the diffusion member 23 and the positive electrode 21 are separated from each other to form a space therebetween, and the first nozzle 261 may be connected to this space instead of the side surface of the diffusion member 23. The number of packings such as the first packing 271 is not particularly limited, and may be three or more.

  In addition, here, the configuration in which the air supply port is provided in the main body has been described, but the place where the air supply port is provided is not limited as long as air can be supplied to the positive electrode. For example, an air supply port is provided in the pipe for feeding the electrolyte, preferably an upstream pipe for supplying the electrolyte to the main body of the air battery, and air is mixed into the electrolyte to You may make it reach | attain a positive electrode with electrolyte solution.

  The air battery according to the present invention can be manufactured by mounting each member such as a positive electrode, a negative electrode, and a diffusing member on the exterior material molded into a desired shape. Further, the exterior material may be further divided into two or more members, and a positive electrode, a negative electrode, a diffusion member, and the like may be attached at the time of assembly.

  In the air battery according to the present invention, since the negative electrode is supported in surface contact by the support surface of the diffusing member, the negative electrode is stably held in the main body portion and is prevented from falling off even when the discharge progresses and is consumed. The As a result, stable power generation performance can be obtained. Moreover, the negative electrode and the electrolytic solution are efficiently in contact with each other by the diffusion member, and excellent power generation performance is obtained. In addition, the air battery according to the present invention is suitable for providing the shielding structure and the oxygen selective permeable membrane, and the combined use thereof suppresses a change in the quality of the electrolytic solution, and a more stable power generation performance is obtained.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.

<Production of positive electrode>
[Production Example 1]
Acetylene black as a conductive material, electrolytic MnO ₂ as an oxygen reduction catalyst, and PTFE powder as a binder were mixed (acetylene black: electrolytic MnO ₂ : PTFE = 10: 10: 1, mass ratio) to obtain a mixture. . The obtained mixture was molded to have a diameter of 15 mm and a thickness of 0.3 mm, and then pressed onto a stainless steel mesh positive electrode current collector (diameter 30 mm, thickness 0.1 mm). Further, an external connection nickel ribbon terminal (length 50 mm, width 3 mm, thickness 0.20 mm) was connected to the end of the positive electrode current collector. As described above, the first laminate shown in FIG.

In the obtained first laminate, a porous membrane made of polyvinylidene fluoride ("Durapore membrane filter" manufactured by Millipore, diameter 22 mm, as a hydrophobic membrane so as to cover the cathode catalyst layer on the cathode current collector. (Thickness 0.1 mm) was laminated to produce a second laminate shown in FIG.
Next, the obtained second laminate was sandwiched and pressed between two ring-shaped rubber plates having openings to produce a positive electrode (1) shown in FIG. 3 (c).

[Production Example 2]
A positive electrode (2) was produced in the same manner as in Production Example 1 except that an oxygen selective permeable membrane was used instead of the polyvinylidene fluoride porous membrane. The oxygen selective permeable membrane is a silicone membrane having an electrolyte contact angle of 105 ° (“Silicon film” manufactured by ASONE Co., Ltd., thickness 0.1 mm), and an oxygen selectivity coefficient (PO ₂ ) of 620 × 10 ⁻¹⁰ cm ^3. The selective permeability of oxygen / carbon dioxide was 0.20 at cm / cm ² · s · cmHg.

<Manufacture of negative electrode>
[Production Example 3]
Aluminum in which high-purity aluminum (purity: 99.999% or more) is melted at 750 ° C., magnesium (purity: 99.99% or more) is added to the molten aluminum, and the magnesium content is 2.5 mass%. -A magnesium alloy melt was obtained.
Next, the obtained molten alloy was cleaned by holding at 750 ° C. for 2 hours under the condition of a degree of vacuum of 50 Pa.
Next, the molten alloy was cast using a cast iron mold (22 mm × 150 mm × 200 mm) at 150 ° C. to obtain an ingot.
Next, the obtained ingot was subjected to a solution treatment under the following conditions. That is, the ingot was heated from room temperature (25 ° C.) to 430 ° C. at a rate of 50 ° C./hour and held at 430 ° C. for 10 hours. Subsequently, the temperature was raised to 500 ° C. at a rate of 50 ° C./hour and held at 500 ° C. for 10 hours. Then, it cooled at the speed | rate of 300 degree-C / hr to 500-200 degreeC.
Next, 6 mm of the solution-treated ingot was chamfered by 2 mm, and then processed into an aluminum cylinder having a diameter of 10 mm and a length of 196 mm. Then, it cut | disconnected to length 30mm and produced the negative electrode (1) which consists of aluminum alloys. The content of elements other than aluminum (Al) in the negative electrode (1) was measured using an emission spectroscopic analyzer. The measurement results are shown in Tables 1 and 2.

[Production Example 4]
A negative electrode (2) made of aluminum (aluminum purity: 99.999%) having a diameter of 10 mm and a length of 30 mm was produced in the same manner as in Production Example 3 except that magnesium was not added. The content of elements other than aluminum (Al) in the negative electrode (2) was measured using a glow discharge mass spectrometer. The measurement results are shown in Tables 1 and 2.

[Production Example 5]
Negative electrode (3) made of aluminum having a diameter of 10 mm and a length of 30 mm (aluminum purity: 99%) in the same manner as in Production Example 4 except that aluminum having a purity of 99% was used instead of high-purity aluminum. Was made. The content of elements other than aluminum (Al) in the negative electrode (3) was measured using an emission spectroscopic analyzer. The measurement results are shown in Tables 1 and 2.

<Manufacture of air batteries>
[Example 1]
An air battery (1) having the same configuration as in FIG. 1 was produced. The positive electrode (1) as the positive electrode, the negative electrode (1) as the negative electrode, an aqueous potassium hydroxide solution having a concentration of 1.0 mol / L as the electrolyte, and a zirconia disk (diameter 20 mm, thickness 5.0 mm) as the diffusion member In addition, a 1000 mL polypropylene container was used as a storage means, a liquid feed pump as a liquid feed means, and a polypropylene tube as a pipe.

[Example 2]
An air battery (2) was manufactured in the same manner as in Example 1 except that the main body 2B shown in FIG. 4 was used instead of the main body 2A. As the first packing, “ZF type oil seal (part number AZ0264E0)” manufactured by NOK was used.

[Example 3]
An air battery (3) was produced in the same manner as in Example 1 except that the main body 2C shown in FIG. 5 was used instead of the main body 2A. As the first packing, “ZF type oil seal (part number AZ0264E0)” manufactured by NOK was used.

[Example 4]
An air battery (4) was produced in the same manner as in Example 1 except that the main body 2D shown in FIG. 6 was used instead of the main body 2A. As the first and second packings, “ZF type oil seal (part number AZ0264E0)” manufactured by NOK was used.

[Example 5]
An air battery (5) was produced in the same manner as in Example 4 except that the positive electrode (2) was used in place of the positive electrode (1) in the main body 2D.

[Example 6]
An air battery (6) was produced in the same manner as in Example 5 except that in the main body 2D, the negative electrode (2) was used instead of the negative electrode (1).

[Example 7]
An air battery (7) was produced in the same manner as in Example 5 except that in the main body 2D, the negative electrode (3) was used instead of the negative electrode (1).

[Example 8]
An air battery (8) was produced in the same manner as in Example 4 except that in the main body 2D, the negative electrode (2) was used instead of the negative electrode (1).

[Example 9]
An air battery (9) was produced in the same manner as in Example 4 except that in the main body 2D, the negative electrode (3) was used instead of the negative electrode (1).

[Comparative Example 1]
In the main body 2A, instead of the diffusion member, a cylindrical support is provided in two holes of a ring-shaped spacer (outer diameter 20 mm, thickness 4 mm, hole diameter (inner diameter) 12 mm) having two holes with a diameter of 1 mm on the side surface. An air battery (1R) was manufactured in the same manner as in Example 1 except that a configuration in which members (diameter 1 mm, length 7 mm) were inserted was used.

<Air battery performance test 1>
The air battery manufactured above was connected to a charge / discharge tester (“TOSCAT-3000U” manufactured by Toyo System Co., Ltd.), and constant current discharge (CC discharge) was performed at 23.55 mA (30 mA / cm ^{2 with} respect to the negative electrode). Do. The feeding amount of the electrolyte is 0.5 g / min. The charge / discharge tester is set so that the discharge stops when the battery voltage falls below 0.5V. The air battery performance test is performed according to the following procedure.

[Test Example 1]
The performance test 1 of the air battery (1) of Example 1 is performed. At this time, an unused negative electrode (1) is supplemented separately after 90 hours from the start of discharge.
As a result, the negative electrode is less likely to drop than Test Example 8 described below.

[Test Example 2]
The performance test 1 of the air battery (2) of Example 2 is performed. At this time, the performance test is performed in the same manner as in Test Example 1 except that the negative electrode (1) is pressed from the upper portion thereof every 5 hours to be pressed against the diffusion member (to make up for the space generated by the disappearance in the discharge). . In addition, an unused negative electrode (1) is replenished separately after 90 hours from the start of discharge.
As a result, the negative electrode is less likely to drop than Test Example 8 described below.

[Test Example 3]
In the same manner as in Test Example 2, performance test 1 of the air battery (3) of Example 3 is performed. At this time, an unused negative electrode (1) is supplemented separately after 90 hours from the start of discharge.
As a result, the negative electrode is less likely to drop than Test Example 8 described below.

[Test Example 4]
In the same manner as in Test Example 2, performance test 1 of the air battery (4) of Example 4 is performed. At this time, an unused negative electrode (1) is supplemented separately after 90 hours from the start of discharge.
As a result, the negative electrode is less likely to drop than Test Example 8 described below.

[Test Example 5]
In the same manner as in Test Example 2, performance test 1 of the air battery (5) of Example 5 is performed. At this time, an unused negative electrode (1) is supplemented separately after 90 hours from the start of discharge.
As a result, the negative electrode is less likely to drop than Test Example 8 described below.

[Test Example 6]
In the same manner as in Test Example 5, performance test 1 of the air battery (6) of Example 6 is performed. At this time, an unused negative electrode (2) is supplemented separately after 50 hours from the start of discharge.
As a result, the negative electrode is less likely to drop than Test Example 8 described below.

[Test Example 7]
In the same manner as in Test Example 5, performance test 1 of the air battery (7) of Example 7 is performed.
As a result, the negative electrode is less likely to drop than Test Example 8 described below.

[Test Example 8]
The performance test 1 of the air battery (1R) of Comparative Example 1 is performed in the same manner as Test Example 2.

<Air battery performance test 2>
Each of the air batteries manufactured above was connected to a solar motor, and a discharge test was performed at a current equivalent to 20 mA (25.5 mA / cm ^{2 with} respect to the negative electrode). The amount of electrolytic solution fed was 0.5 g / min. The time when the solar motor stopped rotating was confirmed.

[Test Example 9]
When the performance test 2 of the air battery (4) of Example 4 was performed, the solar motor was rotating even after 8 hours had elapsed from the start of discharge. In addition, the negative electrode is less likely to drop than Test Example 12 described below.

[Test Example 10]
When the performance test 2 of the air battery (8) of Example 8 was performed, the solar motor stopped 60 minutes after the start of discharge. When the aluminum of the negative electrode was confirmed, the surface facing the positive electrode catalyst was white. This whitening indicates aluminum oxidation. In addition, the negative electrode is less likely to drop than Test Example 12 described below.

[Test Example 11]
When the performance test 2 of the air battery (9) of Example 9 was performed, the solar motor stopped 10 minutes after the start of discharge. When the aluminum of the negative electrode was confirmed, the surface facing the positive electrode catalyst was white. This whitening indicates aluminum oxidation. In addition, the negative electrode is less likely to drop than Test Example 12 described below.

[Test Example 12]
When the performance test 2 of the air battery (1R) of Comparative Example 1 was performed, the solar motor stopped 30 minutes after the start of discharge. When the aluminum of the negative electrode was confirmed, the surface facing the positive electrode catalyst was not flat but white. This whitening indicates aluminum oxidation.

  Since the present invention can be used in the energy field, it is extremely useful industrially.

  DESCRIPTION OF SYMBOLS 1 ... Air battery, 2A, 2B, 2C, 2D ... Main-body part, 201 ... Air supply port, 202 ... Negative electrode supply port, 205 ... Gap part, 21 ... Positive electrode, 21b ... Cathode catalyst layer, 21c ... Hydrophobic membrane (oxygen selective permeable membrane), 22 ... Negative electrode, 22a ... Bottom surface of negative electrode, 23 ... Diffusion member, 23a ... Top surface of diffusion member (Support surface), 271 ... first packing, 272 ... second packing, 3 ... electrolyte, 4 ... reservoir, 5 ... liquid feeding means, 6 ... piping

Claims (22)

A main body provided with a diffusion member having a positive electrode including a positive electrode catalyst, a negative electrode, and a surface supporting the negative electrode;
An air supply port for supplying air to the positive electrode;
An electrolyte,
Circulating means for circulating the electrolyte solution in the main body,
An air battery comprising:
The negative electrode can be continuously replenished from the negative electrode replenishment port to the main body,
Said electrolyte passes through the interior of said diffusion member, wherein the negative electrode, an air battery, which is reachable in supported surface to the top surface of the diffusion member.   The air battery according to claim 1, wherein the diffusion member is made of a porous insulating material that does not react with the electrolytic solution.   The air battery according to claim 2, wherein the porous insulating material is zirconia.   The air battery according to any one of claims 1 to 3, further comprising a shielding structure in which the electrolytic solution in the main body is shielded from the outside on the negative electrode supply port side.   The air battery according to claim 4, wherein the shielding structure has a first packing that seals between the negative electrode and the main body within the main body.   The air battery according to claim 5, wherein the first packing is further disposed in contact with the diffusion member.   The air battery according to any one of claims 4 to 6, wherein the shielding structure further includes a second packing that seals between the negative electrode and the main body within the main body.   The air battery according to claim 7, wherein a gas or a liquid that does not react with the negative electrode is sealed in a gap between the first packing and the second packing.   The air battery according to any one of claims 5 to 8, wherein one or both of the first packing and the second packing are O-shaped.   The air battery according to claim 1, wherein the negative electrode has a prismatic shape or a cylindrical shape.   The air battery according to any one of claims 1 to 10, wherein the negative electrode is made of aluminum or an aluminum alloy. The air battery according to claim 11, wherein the negative electrode is made of an aluminum alloy, and the aluminum alloy satisfies the following condition:
Magnesium content is 0.0001-8 mass%,
Satisfy at least one of the following (a) and (b),
(A) Iron content is 0.0001-0.03 mass%
(B) Content of silicon is 0.0001-0.02 mass%
And content of elements other than aluminum, magnesium, silicon, and iron is 0.005 mass% or less, respectively.   The air battery according to claim 12, wherein the total content of elements other than aluminum and magnesium in the aluminum alloy is 0.1 mass% or less. The negative electrode is made of an aluminum alloy, and the aluminum alloy includes intermetallic compound particles in an alloy matrix;
Among the intermetallic compound particles observed on the surface of the alloy, the density of particles having a surface area of 0.1 μm ² or more and less than 100 μm ² is 1000 / mm ² or less, and the density of particles of 100 μm ² or more is 10 / Mm ² or less,
The air battery according to any one of claims 11 to 13, wherein an area occupied by the intermetallic compound particles per unit surface area of the alloy is 0.5% or less.   The electrolyte solution is an aqueous solution containing at least one electrolyte selected from the group consisting of potassium hydroxide, sodium hydroxide, lithium hydroxide, barium hydroxide, and magnesium hydroxide. The air battery described in 1.   The air battery according to claim 1, wherein the positive electrode catalyst contains manganese dioxide or platinum. The positive electrode catalyst includes a perovskite complex oxide represented by a general formula “ABO ₃ ”, A includes two or more elements selected from the group consisting of lanthanum, strontium, and calcium, and B includes manganese, iron, The air battery according to any one of claims 1 to 15, comprising one or more elements selected from the group consisting of chromium and cobalt.   The air battery according to any one of claims 1 to 17, further comprising an oxygen selective permeable membrane that allows oxygen to permeate the air supplied from the air supply port and reach the positive electrode.   The air battery according to claim 18, wherein a contact angle of the electrolytic solution with respect to a surface of the oxygen selective permeable membrane is 90 ° or more.   The air battery according to claim 19, wherein the contact angle is 150 ° or more. The air battery according to any one of claims 18 to 20, wherein an oxygen selection coefficient of the oxygen selective permeable membrane is 400 x 10 ^-10 cm ³ · cm / cm ² · s · cmHg or more.   The air battery according to any one of claims 18 to 21, wherein a selective permeability of oxygen / carbon dioxide of the oxygen selective permeable membrane is 0.15 or more.

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