JPWO2020179645A1 - Negative electrode and metal-air battery - Google Patents

Abstract

The negative electrode includes a negative electrode case having at least one opening, a negative electrode current collector including a portion housed in the negative electrode case and a portion extended from the negative electrode case, and at least a negative electrode current collector housed in the negative electrode case. It has a negative electrode active material layer in contact with a part thereof, a first porous film covering the opening, and an anion conductive film arranged between the first porous film and the negative electrode active material layer.

Description

The present disclosure relates to negative electrodes and metal-air batteries. This application claims priority based on Japanese Patent Application No. 2019-039922 filed in Japan on March 5, 2019, the contents of which are incorporated herein by reference.

A metal air battery has a positive electrode (air electrode), a negative electrode (metal negative electrode), and an electrolyte (electrolyte solution) and has a high energy density. It is being advanced. This type of metal-air battery is housed in an outer container with an insulating separator interposed between the positive electrode and the negative electrode.

In a metal-air battery, the metal contained in the negative electrode becomes metal ions during discharge and diffuses into the electrolyte, and precipitates in the form of needles during charging. Therefore, in a metal-air battery, dendrites (needle-shaped metal precipitates) grown due to repeated charging and discharging may penetrate the separator and short-circuit the positive electrode and the negative electrode.

On the other hand, for example, in Patent Document 1, by providing an anionic conductive film as a separator between the positive electrode and the negative electrode of a metal-air battery, a metal is provided while ensuring good permeability of anions required for an electrode reaction. A configuration is disclosed in which an attempt is made to suppress the growth of dendrite, which causes a short circuit between the positive electrode and the negative electrode, while suppressing the diffusion of ions.

Japanese Unexamined Patent Publication No. 2017-162773

In the metal-air battery disclosed in Patent Document 1, the negative electrode is pressure-bonded to the positive electrode via an anionic conductive film which is a separator. This is intended to prevent the negative electrode active material from slipping off due to the action of gravity from the surface of the negative electrode that is in close contact with the positive electrode via the separator. However, since the positive electrode is pressure-bonded to the anion conductive film, friction is generated between the anion conductive film and the positive electrode. Further, as oxygen is generated and consumed in the positive electrode by charging / discharging, pressure fluctuation occurs in the outer container, and the anion conductive film may be pressed against the positive electrode. Due to such friction and pressing, the anion conductive film is liable to be damaged or ruptured, dendrites are generated, and there is a problem that the positive electrode and the negative electrode are short-circuited.

The present disclosure has been made in view of the above-mentioned conventional problems, and an object thereof is a negative electrode suitable for suppressing the growth of dendrites and suppressing a short circuit between electrodes, and a negative electrode thereof. Is to provide a metal-air battery equipped with.

The negative electrode of the present disclosure for achieving the above object is a negative electrode current collector including a resin case having at least one opening, a portion housed in the case, and a portion extended from the case. A negative electrode active material layer containing a negative electrode active material housed in the case and in contact with at least a part of the negative electrode current collector, a first porous film covering the opening, the first porous film and the negative electrode. It is characterized by having an anionic conductive film arranged between the active material layer and the active material layer.

Due to this specific matter, the negative electrode active material is housed in the case and its sliding is suppressed. Further, since the first porous membrane is arranged between the anion conductive membrane and the opening of the case, it is possible to prevent damage to the anion conductive membrane and the like. By preventing damage to the anion conductive film and the like, it is possible to eliminate the path through which dendrites grow. Therefore, the growth of dendrites can be effectively suppressed, and short circuits between the electrodes can be prevented.

As a more specific configuration of the negative electrode, it is preferable that the opening is covered with the first porous film inside the case. As a result, the negative electrode expands due to repeated charging and discharging, and the space between the opening peripheral edge of the case and the anion conductive film, which tends to be a growth path for dendrites, can be reinforced by the first porous film. It is possible to prevent damage / breakage of the anion conductive film or peeling of the anion conductive film from the opening peripheral edge of the case. In addition, the integrity of the case and the first porous membrane is enhanced, the growth path of dendrites can be blocked, and a short circuit between the electrodes can be prevented.

In the negative electrode having the above configuration, it is preferable that the case and the first porous film are welded together. As a result, in the region where the case and the first porous membrane are welded, the respective components of the case and the first porous membrane are melted, and the pores of the first porous membrane can be closed. Therefore, even in the peripheral portion of the first porous membrane, which tends to be a dendrite growth path, the dendrite growth path can be blocked and a short circuit between the electrodes can be prevented.

Further, in the negative electrode having the above configuration, it is preferable that the anion conductive film is in contact with the inner surface of the case. As a result, the growth path of the dendrite can be narrowed while maintaining the distance between the positive electrode and the negative electrode, so that a short circuit between the electrodes can be further prevented.

Further, in the negative electrode having the above configuration, it is preferable that the anion conductive film is covered with the first porous film from the inside of the case and extends outward from the peripheral edge of the first porous film. .. Even with such a configuration, the growth path of the dendrite can be narrowed, so that it is possible to further prevent a short circuit between the electrodes.

More specifically, the anion conductive film in the negative electrode having the above structure is preferably configured to contain a polymer containing an anion exchange group or a layered double hydroxide. Further, it is preferable that the anion conductive film is configured to suppress the permeation of zincate ions and allow the permeation of hydroxide ions. With such a configuration, the anion conductive film can be provided with good anion permeation performance.

Further, more specifically, the air permeability of the first porous film in the negative electrode having the above configuration is preferably 0.1 to 1000 seconds in terms of Garley value. Further, it is preferable that the first porous membrane has a large number of micropores having communication, and the average pore diameter of the micropores is 0.1 to 100 μm. By being configured in this way, the first porous membrane can be expected to have a buffering action in the thickness direction, and can also retain the electrolyte in the micropores.

Further, in the negative electrode having the above structure, a second porous film may be provided between the anion conducting film and the negative electrode active material layer. This makes it possible to further prevent damage to the anion conductive film and the like.

Further, in the negative electrode having the above configuration, it is preferable that the case contains an electrolyte. As a result, the electrolyte can be held in the case and the charge / discharge reaction can be efficiently performed.

Further, a metal-air battery provided with a negative electrode according to the above configuration is also within the scope of the technical idea of the present disclosure. That is, the metal air cell of the present disclosure includes a negative electrode, a positive electrode, and an electrolyte, and the negative electrode is housed in a resin case having at least one opening and the case, and is extended from the case. A negative electrode current collector, a negative electrode active material layer containing a negative electrode active material housed in the case and in contact with at least a part of the negative electrode current collector, a first porous film covering the opening, and the first porous film. It is characterized by comprising an anionic conductive film arranged between the film and the negative electrode active material layer, and the positive electrode is arranged so as to face the opening.

According to this specific matter, it is possible to suitably form a metal-air battery having a structure capable of suppressing the growth of dendrites in the negative electrode and preventing a short circuit between the electrodes.

More specifically, in the metal-air battery, the positive electrode includes a first positive electrode for discharging and a second positive electrode for charging, and the first positive electrode, the second positive electrode, and the negative electrode. It is preferable that they are arranged in the order of.

Further, in the metal-air battery, as the opening, a first opening and a second opening are provided on both sides of the negative electrode active material layer in the thickness direction, respectively, and the positive electrode is a first for discharging. A configuration including a positive electrode and a second positive electrode for charging, the first positive electrode is arranged facing the first opening, and the second positive electrode is arranged facing the second opening. May be.

By being configured in this way, the metal-air battery can effectively block the growth path of dendrites and prevent a short circuit between the electrodes.

In the negative electrode and the metal-air battery provided with the negative electrode according to the present disclosure, it is possible to prevent damage or breakage of the anionic conductive film and suppress the growth of dendrite that causes a short circuit between the electrodes, thereby improving the battery performance. Can be made to.

It is sectional drawing which shows typically the negative electrode which concerns on Embodiment 1 of this disclosure. It is a perspective view which shows the negative electrode. It is a perspective view which shows the metal-air battery which concerns on Embodiment 1 of this disclosure. It is a perspective view which shows the negative electrode which concerns on Embodiment 2. FIG. It is a partially enlarged sectional view schematically showing the negative electrode. It is sectional drawing which shows typically the negative electrode which concerns on Embodiment 3. FIG. It is sectional drawing which shows typically the negative electrode which concerns on Embodiment 4. FIG. It is sectional drawing which shows typically the metal-air battery which concerns on Embodiment 5. It is sectional drawing which shows typically the metal-air battery which concerns on Embodiment 6.

Hereinafter, the negative electrode and the metal-air battery provided with the negative electrode according to the embodiment of the present disclosure will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a cross-sectional view schematically showing a negative electrode 1 according to the first embodiment of the present disclosure. FIG. 2 is a perspective view showing the negative electrode 1 according to the first embodiment. For convenience of explanation, the upper part of the figure in FIG. 1 is assumed to be the upper part of the negative electrode 1 and the metal-air battery 10 provided with the negative electrode 1, and will be described below.

(Negative electrode)
The negative electrode 1 contains a metal serving as an electrode active material, constitutes a metal air battery 10 together with a positive electrode 8 and a battery case 9, and extracts electrical energy obtained in the process of changing a metal into a metal oxide by an electrochemical reaction. .. The negative electrode 1 includes a resin negative electrode case (case) 2, a negative electrode current collector 3, a negative electrode active material layer 4, a first porous film 5, and an anion conductive film 6.

The negative electrode case 2 of the negative electrode 1 is provided with at least one opening 20, and houses the negative electrode current collector 3 inside. The negative electrode case 2 is formed by, for example, folding and joining one or a plurality of sheet-shaped insulating film materials.

In the embodiment shown in FIGS. 1 and 2, the negative electrode case 2 is provided with an opening 20 penetrating inside and outside so as to face both one surface and the other surface of the negative electrode current collector 3. That is, the openings 20 are formed on the surfaces of the negative electrode case 2 facing each other with the negative electrode current collector 3 interposed therebetween.

The size of each opening 20 is smaller than the size of one of the surfaces of the negative electrode current collector 3 housed in the negative electrode case 2. Dendrites tend to grow at the ends of the negative electrode current collector 3 or the negative electrode active material layer 4. Therefore, by making the size of each opening 20 smaller than the size of one of the surfaces of the negative electrode current collector 3, the electrode reaction is less likely to occur at the end of the negative electrode current collector 3 or the negative electrode active material layer 4. Therefore, the growth of dendrite can be suppressed.

The negative electrode current collector 3 is made of a material that is porous and has electron conductivity. For example, for the negative electrode current collector 3, from the viewpoint of suppressing self-corrosion, a material having a high hydrogen overvoltage or a material in which the surface of a metal material such as stainless steel is plated with a material having a high hydrogen overvoltage is used. Further, the negative electrode current collector 3 may be formed of a mesh, an expanded metal, a punching metal, a sintered body of metal particles or metal fibers, a foamed metal, or the like.

A lead portion 31 is extended as a negative electrode terminal in the negative electrode current collector 3, and can be electrically connected to an external circuit. The negative electrode current collector 3 is housed in the negative electrode case 2 in a state where the lead portion 31 is extended from the upper part of the negative electrode case 2. This makes it possible to transfer the electric charge consumed or generated by the negative electrode 1 to an external circuit (not shown).

The negative electrode active material layer 4 is arranged in the negative electrode case 2 so as to be in contact with both sides of the negative electrode current collector 3, and has a negative electrode active material containing a metal element as the electrode active material. As such a metal element, zinc, lithium, sodium, calcium, magnesium, aluminum, iron and the like are preferable.

In the exemplary embodiment, the negative electrode active material layer 4 may be a layer made of a metal in a reduced state or a layer made of a metal in an oxidized state. For example, particulate zinc or zinc oxide can be used for the negative electrode active material layer 4. When the metal element is zinc, it is metallic zinc in the reduced state and zinc oxide in the oxidized state. The negative electrode 1 containing zinc can be taken out from the battery case 9 after discharging, and zinc oxide can be reduced to zinc.

When the metal element is zinc, an oxidation reaction of metallic zinc occurs at the time of discharge. That is, as a result of zinc oxidation, it may be dissolved as zincate ions in the electrolytic solution, or zinc oxide or zinc hydroxide may be directly produced. During charging, a reduction reaction to metallic zinc occurs. That is, there are cases where zinc is produced by the reduction of zincate ions dissolved in the electrolytic solution, and cases where zinc oxide and zinc hydroxide are directly reduced to zinc.

・ First porous membrane 5
A first porous film 5 having an insulating porous structure is attached to each of the two openings 20 of the negative electrode case 2, and these openings 20 are covered. The first porous film 5 is housed inside the negative electrode case 2, and is arranged so as to cover the opening 20 from the inside of the negative electrode case 2.

As shown in FIG. 1, in the negative electrode case 2 of the negative electrode 1, the first porous film 5 is configured to intervene between the anion conductive film 6 described later and the opening 20. Further, the positive electrode 8 described later is closely arranged in the first porous film 5 through the opening 20 of the negative electrode case 2.

As a result, the first porous film 5 covers the opening 20 of the negative electrode case 2 and intervenes between the internal and external constituent members of the negative electrode case 2 and acts as a buffer layer thereof. That is, the anion conductive film 6 arranged in the negative electrode case 2 is prevented from coming into contact with the edge of the opening 20 by the first porous film 5. The positive electrode 8 arranged outside the negative electrode case 2 abuts on the opening 20, but is arranged without contacting the anion conductive film 6.

Although FIG. 1 shows a configuration in which the first porous film 5 is arranged so as to cover the opening 20 from the inside of the negative electrode case 2, the opening 20 of the first porous film 5 is provided from the outside of the negative electrode case 2. It may be arranged so as to cover it. Even with such an arrangement, it is possible to prevent the positive electrode 8 arranged outside the negative electrode case 2 from coming into contact with the anion conductive film 6.

As for the arrangement of the first porous film 5, the arrangement that covers the opening 20 from the inside of the negative electrode case 2 is more preferable than the arrangement that covers the opening 20 from the outside. This is because when the first porous film 5 is arranged so as to cover the opening 20 from the inside of the negative electrode case 2, it is possible to prevent the edge portion of the opening 20 and the positive electrode 8 from coming into contact with the anion conductive film. ..

Since the first porous membrane 5 is responsible for ionic conductivity between the positive electrode 8 and the negative electrode 1, it is formed of a porous member capable of holding an electrolyte in the pores, and a non-woven fabric made of polyolefin, filter paper, or the like may be used. can. In addition to these, the first porous membrane 5 may contain, for example, an inorganic substance such as titanium oxide, niobium oxide, and tantalum oxide.

Further, the first porous membrane 5 preferably has an air permeability represented by a Garley value of 0.1 to 1000 seconds. The Garley value is an index showing the ease of passage of gas, and the larger the value, the more difficult it is for gas to pass through. The Garley value of the first porous membrane 5 can be easily measured by the measuring method specified in JIS P 8117.

The Garley value in the first porous membrane 5 is preferably 0.1 seconds or longer. The Garley value is preferably up to 1000 seconds, and the upper limit is more preferably 100 seconds. If the Garley value is less than 0.1 seconds, there are too many voids, so that the strength required for the buffer layer is insufficient, and the first porous membrane 5 may be damaged. If the Garley value is larger than 1000 seconds, there are too few voids, which hinders ion conduction and causes an increase in battery resistance.

Further, when the first porous membrane 5 has a large number of micropores having ionic conductivity and communication on both the front and back surfaces, the average pore diameter of these micropores is 0.1 to 100 μm. It is preferable to have. More preferably, the average pore diameter of the micropores is 1 to 50 μm.

The pore diameter of the first porous membrane 5 is non-uniform in the case of a non-woven fabric or a woven fabric, but it is preferable that the average pore diameter is configured within the above range.

By attaching such a first porous film 5 to the opening 20, it is possible to suppress damage or breakage of the anion conductive film that causes the growth path of dendrites, and the occurrence of a short circuit due to dendrites can be suppressed. Can be suppressed.

・ Anion conductive film 6
An anion conductive film 6 is arranged between the first porous film 5 and the negative electrode active material layer 4. The anion conductive film 6 enables the movement of anions between these members while ensuring the insulating property between the positive electrode 8 and the negative electrode 1, and prevents a short circuit due to the formation of an electron conduction path between the electrodes. The anion conductive film 6 is ^{a film that allows anions such as hydroxide ions (OH −} ) involved in the battery reaction to pass through, and contains organic substances and inorganic substances.

The gincate ions generated by the discharge reaction of the negative electrode 1 diffuse in the charging electrode in the battery, which causes a short circuit failure of the battery. The anion conductive film 6 has the conductivity of hydroxide ions and allows the permeation of hydroxide ions. On the other hand, the anion conductive film 6 preferably suppresses the permeation of the gincate ions and inhibits the diffusion of the gincate ions.

Further, the anion conductive film 6 has the selectivity of the permeating anion due to the action of an inorganic substance or the like described later. As for the selectivity of anions, for example, anions such as hydroxide ions are easily permeated, and even if they are anions, permeation of metal-containing ions derived from an active material having a large ionic radius is sufficiently prevented. The anion conduction in the anion conduction film 6 means that an anion having a small ionic radius such as a hydroxide ion is sufficiently permeated, and has an anion permeability. Anions with a large ionic radius, such as metal-containing ions, are more difficult to permeate and may not permeate at all.

The inorganic substances contained in the anion conductive film 6 include alkali metals, alkaline earth metals, Mg, Sc, Y, lanthanoids, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Fe, and Ru. , Co, Ni, Pd, Cu, Ag, Au, Zn, Cd, B, Al, Ga, In, Tl, C, Si, Ge, Sn, Pb, N, P, Sb, Bi, S, Se, Te , F, Cl, and Br, preferably at least one element selected from the group.

Examples of the inorganic substance include layered inorganic compounds such as oxides, composite oxides and layered compound hydroxides, hydroxides, clay compounds, solid solutions, alloys, zeolites, halides, carboxylate compounds, carbonate compounds and hydrogen carbonates. Compounds, nitrate compounds, sulfuric acid compounds, sulfonic acid compounds, phosphoric acid compounds such as hydroxyapatite, phobic compounds, hypophobic acid compounds, boric acid compounds, silicic acid compounds, aluminic acid compounds, sulfides, onium compounds, salts, etc. Can be mentioned. Among them, layered double hydroxides such as oxides, composite oxides and hydrotalcites, hydroxides, clay compounds, solid solutions, zeolites, fluorides, phosphoric acid compounds, boric acid compounds, silicic acid compounds, aluminic acid compounds, Salt is preferred.

Further, as the oxide, for example, cerium oxide and zirconium oxide are preferable. More preferably, it is cerium oxide. Further, the cerium oxide may be, for example, one doped with a metal oxide such as samarium oxide, gadolinium oxide or bismuth oxide, or a solid solution with a metal oxide such as zirconium oxide. The oxide may have an oxygen defect. As the hydroxide, for example, magnesium hydroxide, cerium hydroxide, and zirconium hydride are preferable.

The layered inorganic compound constituting the anion conductive film 6 may be a single layer or a laminated layer of two or more layers. Examples of the layered inorganic compound include layered double hydroxides. This layered double hydroxide is expressed by the following equation;
^{_{[M 1 1 - x M 2}} x (OH) 2] (A n-) x / n · mH 2 O
(M ¹ represents a divalent metal ion which is any one of Mg, Fe, Zn, Ca, Li, Ni, Co, Cu and Mn. M ² represents Al, Fe, Mn, Co, Cr and In. the ^.A n-representing a trivalent metal ion is ^{_{either, OH -, Cl -, NO}} 3 -, CO 3 2-, COO - .m representing a 1-3-valent anion such as 0 or more N is a number from 1 to 3; x is a number from 0.2 to 0.40). ^{It is preferable that An−} is a divalent or less anion.

When the anion conductive film 6 is composed of the layered double hydroxide, it is preferable to obtain a dense layer by molding and / or firing the particles of the layered double hydroxide, and the layered double hydroxide such as a porous matrix binder is preferable. It may be a complex with an auxiliary component that helps densification and immobilization of the oxide particle group.

Examples of the organic substance contained in the anionic conductive film 6 include hydrocarbon site-containing polymers typified by polyolefins such as polyethylene and polypropylene, aromatic group-containing polymers typified by polystyrene and the like; alkylene glycols such as polyethylene oxide and polypropylene oxide. Typical ether group-containing polymers; for polyvinyl alcohol, poly (α-hydroxymethylacrylate), cellulose, methylcellulose, hydroxyethylmethylcellulose, hydroxypropylmethylcellulose, hydroxyalkylcellulose (for example, hydroxyethylcellulose, hydroxypropylcellulose, etc.), etc. Representative hydroxyl group-containing polymers; amide bond-containing polymers typified by polyamide, nylon, polyacrylamide, polyvinylpyrrolidone, N-substituted polyacrylamide, etc .; imide bond-containing polymers typified by polymaleimide, polyimide, etc.; (meth) acrylic (Meta) acrylic polymer containing a monomer unit derived from an acid alkyl ester monomer as a main component; poly (meth) acrylic acid (salt), polymaleic acid (salt), polyitaconic acid (salt), polymethyleneglutaric acid (salt), Carboxy group-containing polymers typified by carboxymethyl cellulose (including carboxy group metal salts (alkali metals, etc.), ammonium salts, etc.); A carboxylate-containing polymer typified by a salt; a halogen atom-containing polymer such as polyvinyl chloride, polyvinylidene fluoride, polytetrafluoroethylene; a polymer bonded by opening an epoxy group such as an epoxy resin; a sulfonic acid (sulfonic acid ( Salt) site-containing polymer; AR ¹ R ² R ³ B (A stands for N or P; B stands for halogen anion or anion such as OH ^−; R ¹ , R ² and R ³ are the same or different. Represents an alkyl group having 1 to 7 carbon atoms, a hydroxyalkyl group, an alkylcarboxyl group, and an aromatic ring group. R ¹ , R ² , and R ³ may be bonded to form a ring structure). A quaternary ammonium salt or a quaternary phosphonium salt-containing polymer typified by a polymer to which a group is bonded; an ion-exchangeable polymer used for a cation / anion exchange film, etc .; Rubbery polymer with unsaturated carbon bonds in the chain; cellulose acetate, chitin, chitosan, a Sugars typified by ruginic acid (salt); amino group-containing polymers typified by polyethyleneimine; carbamate group site-containing polymers; carbamide group site-containing polymers; epoxy group site-containing polymers; heterocycles and / or ionized Examples include a polymer containing a heterocyclic moiety; a polymer alloy; a polymer containing a heteroatom; a low molecular weight surfactant and the like, and one or more of these can be used.

-Electrolyte An electrolyte is housed in the negative electrode case 2 containing the negative electrode current collector 3, the negative electrode active material layer 4, the anionic conductive film 6, and the first porous membrane 5. The electrolyte is not particularly limited as long as it is usually used as an electrolyte for a battery, and examples thereof include a water-containing electrolyte, an organic solvent-based electrolyte, and the like, and a water-containing electrolyte is more preferable.

The water-containing electrolytic solution refers to an electrolytic solution (aqueous electrolytic solution) that uses only water as a solvent raw material, or an electrolytic solution that uses a solution obtained by adding an organic solvent to water as a solvent raw material. Examples of the aqueous electrolytic solution include potassium hydroxide aqueous solution, sodium hydroxide aqueous solution, lithium hydroxide aqueous solution, zinc sulfate aqueous solution, zinc nitrate aqueous solution, zinc phosphate aqueous solution, zinc acetate aqueous solution and the like. The electrolyte is not particularly limited, but when an aqueous electrolyte is used, it is preferably a compound that generates hydroxide ions responsible for ion conduction in the system. From the viewpoint of ionic conductivity, an aqueous solution of potassium hydroxide is more preferable. The aqueous electrolyte may be one type or two or more types.

Further, the electrolytic solution immerses the negative electrode 1 and the positive electrode 8 in the battery case 9. As shown in FIG. 1, in the negative electrode 1 (and the metal-air battery 10) according to the first embodiment, the liquid layer due to the electrolytic solution does not exist, and the negative electrode 1 and the positive electrode 8 are immersed in a wet state with the electrolytic solution. ..

For example, when a zinc-air battery, an aluminum-air battery, or an iron-air battery is applied as the metal-air battery 10, an alkaline aqueous solution such as a sodium hydroxide aqueous solution or a potassium hydroxide aqueous solution can be used as the electrolytic solution, and magnesium. In the case of an air battery, an aqueous sodium chloride solution can be used as the electrolytic solution, and in the case of a lithium air battery, an organic electrolytic solution can be used. Organic additives and inorganic additives other than the electrolyte may be added to the electrolytic solution, or gelled by the polymer additive.

The negative electrode current collector 3, the negative electrode active material layer 4, the anionic conductive film 6 and the first porous film 5 are contained in the negative electrode case 2 and housed in the battery case 9 constituting the metal-air battery 10. The negative electrode case 2 ensures the insulation between the negative electrode current collector 3 and the positive electrode 8 in the battery case 9.

As shown in FIG. 2, the negative electrode case 2 is formed in the shape of a bottomed bag with an open upper portion before being housed in the battery case 9, and the electrolytic solution is injected into the negative electrode case 2. Can be done. The negative electrode case 2 has a margin portion for heat fusion secured on the upper side, and the upper side may be heat-sealed and sealed after injection of the electrolytic solution.

The material of the negative electrode case 2 is not particularly limited as long as it is made of a material that prevents the permeation of the electrolytic solution required for this type of metal-air battery 10 and can function as an insulating member. Preferably, it is formed of a thermoplastic resin material having good insulating properties, less likely to cause wrinkles, and high heat resistance. Specifically, a polyolefin-based resin material such as polyethylene (PE) or polypropylene (PP) can be preferably used. The thickness of the polyolefin-based resin material is preferably 0.2 mm or less, more preferably 30 to 150 μm, and more preferably about 50 to 100 μm.

^{At the negative electrode 1, a reaction involving hydroxide ion (OH −} ) occurs in addition to the negative electrode active material in both the discharge reaction and the charge reaction. Therefore, the negative electrode 1 has a structure in which the negative electrode active material and the ^{electrolyte acting as a conduction path for hydroxide ions (OH −} ) are efficiently contacted. For example, the negative electrode active material is a porous electrode made of active material particles. By doing so, the electrolytic solution permeates the voids between the particles of the active material particles. This makes it possible to widen the contact interface between the active material particles and the electrolytic solution. Further, the negative electrode active material layer 4 may be configured to include a binder, and by including the binder, the negative electrode active materials can be bound to each other.

(Metal-air battery)
FIG. 3 is a perspective view showing the metal-air battery 10 according to the first embodiment. The metal-air battery 10 includes a battery case 9, a negative electrode 1, and a positive electrode 8.

As shown in FIG. 1, the positive electrode 8 constituting the metal-air battery 10 has a discharge positive electrode (air electrode) 81 which is a first positive electrode for discharge and a charging positive electrode which is a second positive electrode for charging. It has 82 and. A positive electrode 81 for discharging is arranged on one surface of the negative electrode case 2 of the negative electrode 1, and a positive electrode 82 for charging is arranged on the other surface.

・ Battery case 9
The battery case 9 is an outer container that houses the negative electrode 1, the positive electrode for discharging 81, and the positive electrode 82 for charging. In the exemplary embodiment, as shown in FIG. 1, the battery case 9 is arranged outside the negative electrode case 2 and is configured to include the negative electrode 1. In this case, as the battery case 9, the first case 91 arranged to face one opening 20 of the negative electrode case 2 and the second case 92 arranged to face the other opening 20 of the negative electrode case 2 are provided. , The negative electrode 1 is encapsulated inside and bonded to each other.

In each of the first case 91 and the second case 92, a large number of openings are formed so as to penetrate the front and back surfaces. Of these, in the first case 91, the opening is the air intake port 93. Further, in the second case 92, the opening is a gas discharge port 94. The battery case 9 is capable of taking in air into the inside through these air intake ports 93, and also allows gas such as oxygen generated during charging and accumulating in the vicinity of the charging electrode to be taken in through the gas discharge port 94. It is possible to discharge to the outside.

In the manufacturing process, the battery case 9 is arranged so that the first case 91 and the second case 92 face each other and are fused at the outer peripheral portion. The upper end of the battery case 9 can be used as an injection port for injecting the electrolytic solution. The upper end of the battery case 9 is sealed by heat fusion after injecting the electrolytic solution. As shown in FIG. 3, it is preferable that the upper end portion of the battery case 9 is sealed with the negative electrode case 2 sandwiched between the first case 91 and the second case 92.

The material constituting the battery case 9 is preferably a material having corrosion resistance to the electrolytic solution, and preferably a material having heat resistance and heat fusion resistance. For example, the material of the battery case 9 is preferably polyvinyl chloride (PVC), polyvinyl acetate, ABS resin, vinylidene chloride, polyacetal, polyethylene, polypropylene, polyisobutylene, fluororesin, epoxy resin and the like.

In the form shown in FIGS. 1 and 3, as the metal-air battery 10, the negative electrode 1, the positive electrode 81 for discharging, and the positive electrode 82 for charging are immersed in the electrolytic solution (electrolyte) in the battery case 9. An example is a three-pole secondary battery arranged in parallel.

・ Positive electrode for discharge 81
The discharge positive electrode 81 is an electrode that has a catalyst and becomes a positive electrode when the metal-air battery 10 is discharged. In the discharge positive electrode 81, when an alkaline aqueous solution is used as the electrolytic solution, water supplied from the electrolytic solution or the like reacts with oxygen gas supplied from the atmosphere and electrons on the catalyst to react with hydroxide ions (OH ^−. ) Is generated. In the discharge positive electrode 81, the discharge reaction proceeds at the three-phase interface where oxygen (gas phase), water (liquid phase), and electron conductor (solid phase) coexist.

The discharge positive electrode 81 is provided so that oxygen gas contained in the atmosphere can diffuse. For example, the discharge positive electrode 81 is provided so that at least a part of the surface of the discharge positive electrode 81 is exposed to the atmosphere. In the exemplary embodiment, oxygen gas contained in the atmosphere is diffused into the discharge positive electrode 81 through a large number of air intake ports 93 of the battery case 9.

The discharge positive electrode 81 may be configured to include a discharge positive electrode current collector, a discharge positive electrode catalyst layer including a catalyst, and a water-repellent film. The positive electrode current collector for discharge is preferably a material having porousness and electron conductivity. When an alkaline aqueous solution is used as the electrolytic solution, it is desirable to use a material in which the surface of a metal material such as nickel or stainless steel is nickel-plated from the viewpoint of corrosion resistance. By using a mesh, expanded metal, punching metal, sintered body of metal particles or metal fibers, foamed metal, or the like, the positive electrode current collector for discharge can be made porous.

The positive electrode current collector for discharge may function as a gas diffusion layer. In this case, the positive electrode current collector for electric discharge is a carbon paper or carbon cloth surface-treated with a water-repellent resin, or a porous sheet made of carbon black and a water-repellent resin. The water-repellent resin is provided to prevent the electrolytic solution from leaking from the battery case 9, has a gas-liquid separation function, and does not interfere with the supply of oxygen gas to the catalyst layer.

The water-repellent film is a porous material containing a water-repellent resin, and is arranged on the side opposite to the negative electrode 1. By disposing the water-repellent film, leakage of the electrolytic solution can be suppressed. As the water-repellent resin used for the water-repellent film, for example, polytetrafluoroethylene (PTFE) is preferable.

The discharge positive electrode 81 can be electrically connected to the discharge positive electrode terminal (air electrode terminal), and the electric charge generated in the catalyst layer can be taken out to an external circuit (not shown).

-Charging positive electrode 82
The charging positive electrode 82 is a porous electrode that acts as a charging positive electrode. In the charging positive electrode 82, when an alkaline aqueous solution is used as the electrolytic solution, a reaction occurs in which oxygen, water, and electrons are generated from ^{hydroxide ions (OH −) (charging reaction).} That is, in the charging positive electrode 82, the charging reaction proceeds at the three-phase interface where oxygen (gas phase), water (liquid phase), and electron conductor (solid phase) coexist.

The charging positive electrode 82 is provided so that a gas such as oxygen gas generated by the progress of the charging reaction can be diffused. For example, the charging positive electrode 82 is provided so that at least a part thereof communicates with the outside air. In the exemplary embodiment, gas such as oxygen gas generated by the charging reaction is discharged from the charging positive electrode 82 through a large number of gas discharging ports 94 of the battery case 9.

The charging positive electrode 82 is preferably made of a material having porousness and electron conductivity. When an alkaline aqueous solution is used as the electrolytic solution, nickel or a metal material such as stainless steel with nickel plating may be used from the viewpoint of corrosion resistance and oxygen evolution catalytic ability for the charging reaction. desirable. The charging positive electrode 82 can be made porous by using a mesh, an expanded metal, a punching metal, a sintered body of metal particles or metal fibers, a foamed metal, or the like as the charging positive electrode 82. The charging positive electrode 82 may be provided with oxygen evolution catalyst particles on the surface thereof to promote the charging reaction. Further, the charging positive electrode 82 may be configured to include a charging positive electrode current collector (not shown).

The charging positive electrode 82 may also be provided with a water-repellent film as in the discharging positive electrode 81. By disposing the water-repellent film, leakage of the electrolytic solution through the positive electrode 82 for charging can be suppressed, gas such as oxygen gas generated by the charging reaction is separated from the electrolytic solution, and the battery case 9 is provided. It is possible to discharge to the outside of. The charging positive electrode 82 can be electrically connected to the charging positive electrode terminal, and can supply the electric charge required for the charging reaction from an external circuit (not shown).

In the metal-air battery 10 configured as described above, as shown in FIG. 3, the negative electrode 1 provided with the negative electrode case 2 is arranged in the battery case 9, and the lead portion 31 of the negative electrode current collector 3 is the negative electrode case 2. It is formed by pulling it out to the outside of the battery case 9 in a state of being stretched from the upper part of the battery case 9. Further, referring to FIG. 1, the components of the negative electrode 1 such as the negative electrode current collector 3 do not come into contact with the battery case 9, and the insulation between the negative electrode current collector 3 and the inner surface of the battery case 9 is ensured. Has been done. The positive electrode 8 is insulated from the negative electrode current collector 3 by the negative electrode case 2 and arranged so as not to come into contact with the positive electrode 8.

As shown in FIG. 1, an anion conducting film 6 is interposed between the electrodes of the negative electrode 1 and the positive electrode 8 (the positive electrode for discharging 81 and the positive electrode for charging 82). Ion conduction occurs between these electrodes via the first porous membrane 5, enabling the charging reaction and discharging reaction of the metal-air battery 10. The anion conductive film 6 enables the movement of anions while ensuring the insulating properties of the positive electrode 8 and the negative electrode 1, and prevents the formation of an electron conduction path. Therefore, the metal-air battery 10 has a structure capable of suppressing the growth of dendrites, and is capable of preventing a short circuit between the electrodes.

In the metal-air battery 10, the negative electrode active material layer 4 may expand or contract with the charge / discharge cycle. On the other hand, in the metal-air battery 10, an anion conductive film 6 and a first porous film 5 and the like constituting the negative electrode 1 including the negative electrode active material layer 4 are housed in the negative electrode case 2. Further, the metal-air battery 10 has a structure in which the negative electrode 1 and the positive electrode 8 are closely arranged in the battery case 9 and there is no liquid layer due to the electrolytic solution between the electrodes. As a result, expansion and the like associated with the charge / discharge cycle are suppressed, and a structure in which the volume does not change easily is realized. Further, even if expansion occurs in the metal-air battery 10, the first porous membrane 5 is interposed between the anionic conductive membrane 6 and the negative electrode case 2 (or between the anionic conductive membrane 6 and the positive electrode 8). Since it serves as a buffer layer, it is possible to prevent the anion conductive film 6 from being pressed and damaged.

In the manufacturing process of the metal-air battery 10, the single-layer structure or multi-layer structure sheet material constituting the negative electrode case 2 is formed into a bottomed bag shape by heat fusion, and the two openings 20 face each other on the side surface. It is opened to form the negative electrode case 2. A first porous film 5 is applied to each opening 20 from the inside, and the opening 20 is closed from the inside of the negative electrode case 2.

Next, the negative electrode current collector 3, the negative electrode active material layer 4, and the anion conductive film 6 are inserted into the negative electrode case 2. Since the first porous membrane 5 is interposed between the anion conducting film 6 and the negative electrode case 2, the anion conducting film 6 may come into contact with the opening 20 of the negative electrode case 2 or with the positive electrode 8. It can be prevented. As a result, the anion conductive film 6 can be arranged in the negative electrode case 2 without damaging it, and the anion conductive film 6 can be fully functioned.

Next, the negative electrode case 2 is housed in the battery case 9, and the positive electrode 8 is arranged between the negative electrode case 2 and the battery case 9. Further, the electrolytic solution is injected into the negative electrode case 2 and the battery case 9 (between the inner surface of the battery case 9 and the outer surface of the negative electrode case 2), and the battery case 9 and the negative electrode case 2 are sealed by heat fusion. This makes it possible to block the growth path of dendrites and prevent short circuits between the electrodes.

The metal-air battery 10 can be applied to, for example, a zinc-air battery, a lithium-air battery, a sodium-air battery, a calcium-air battery, a magnesium-air battery, an aluminum-air battery, an iron-air battery, and the like. It can be suitably used for a zinc-air battery whose negative electrode is a zinc type. Unlike lithium-air batteries, zinc-air batteries do not need to use a flammable electrolyte (electrolyte), and can use an alkaline electrolyte (electrolyte), so they have the advantage of high safety. be. Further, the zinc-air battery has an advantage that the capacity can be easily increased because the negative electrode can be manufactured at a lower cost than the lithium-air battery.

In this embodiment, a three-pole metal-air secondary battery is exemplified as the metal-air battery 10, but the metal-air battery 10 is a primary battery and the charging positive electrode 82 is omitted. You may. Further, the metal-air battery 10 may be in the form of having a catalyst having an oxygen reducing ability and an oxygen generating ability on the positive electrode and using a positive electrode that can be used for both charging and discharging.

(Embodiment 2)
FIG. 4 is a perspective view of the negative electrode 1 according to the second embodiment. FIG. 5 is an enlarged cross-sectional view schematically showing the negative electrode 1 according to the second embodiment, and the portion corresponding to the A1 portion in FIG. 1 is enlarged and shown. Since the embodiments 2 to 6 described below are common to the embodiment 1 in the basic configuration, the configurations specific to each embodiment will be described in detail, and the other configurations are common to the embodiment 1. The description thereof will be omitted by using the reference numerals of.

In the first embodiment, the opening 20 provided in the negative electrode case 2 of the negative electrode 1 is covered with the first porous film 5 from the inside of the negative electrode case 2. In the second embodiment, the negative electrode 1 is further characterized in that a first porous film 5 covering the opening 20 from the inside of the negative electrode case 2 is welded to the negative electrode case 2.

As shown in FIGS. 4 and 5, the opening 20 is covered with a first porous film 5 from the inside of the negative electrode case 2, and the negative electrode case 2 and the first porous film 5 are welded to each other to form a welded region 23. Is provided. The welding region 23 is provided along the peripheral edge of the opening 20 in the negative electrode case 2. In the welding region 23, the first porous film 5 is fixed to the peripheral edge of the opening 20 and integrated with the negative electrode case 2.

Since the negative electrode case 2 and the first porous film 5 are welded in this way, when the anion conductive film 6 is arranged in the negative electrode case 2, the anion conductive film 6 interferes with the opening 20 of the negative electrode case 2. It is prevented from being caught or caught, and the anion conductive film 6 can be smoothly inserted. As a result, not only the workability in manufacturing the negative electrode 1 is improved, but also the anion conductive film 6 can be prevented from being damaged.

Further, by providing the welding region 23, the negative electrode case 2 and the first porous film 5 are closely arranged without a gap. This makes it possible to block the path in which the dendrite grows toward the positive electrode 8, which is even more preferable in preventing a short circuit between the electrodes. In particular, the first porous membrane 5 is welded to the negative electrode case 2, and the micropores of the first porous membrane 5 are closed in the vicinity of the welded region 23. Therefore, in the welding region 23, the inside and outside of the negative electrode case 2 (negative electrode 1) are blocked, and the growth path of the dendrite can be blocked.

(Embodiment 3)
FIG. 6 is a cross-sectional view schematically showing the negative electrode 1 according to the third embodiment, and is a diagram corresponding to FIG. 1 in the first embodiment. The negative electrode 1 according to the third embodiment is characterized by the anion conductive film 6, and other configurations are common to those of the first or second embodiment.

As shown in FIG. 6, the anion conductive film 6 is provided between the negative electrode active material layer 4 and the first porous film 5 so as to be in contact with the inner surface of the negative electrode case 2. The anion conductive film 6 is larger than the size of the first porous film 5 covering the opening 20, and has a size extending outward from the outer edge portion of the overlapping first porous film 5. ing.

As a result, the gap formed between the anion conductive film 6 and the negative electrode case 2 is smaller than that shown in FIG. 1 when the anion conductive film 6 is arranged in the negative electrode case 2. Therefore, the path through which the dendrite grows toward the positive electrode 8 can be lengthened and blocked, which is even more preferable in preventing a short circuit between the electrodes.

Note that FIG. 6 shows a state in which the lower end portion of the anion conductive film 6 is in contact with the inner surface of the negative electrode case 2 and the upper end portion is not in contact with the inner surface of the negative electrode case 2. The arrangement of the anion conductive film 6 in the negative electrode 1 is not limited to this, and if the anion conductive film 6 has a size larger than that of the first porous film 5, it should be in contact with the inner surface of the negative electrode case 2. The contact form between the negative electrode case 2 and the anion conductive film 6 may be any.

(Embodiment 4)
FIG. 7 is a cross-sectional view schematically showing the negative electrode 1 according to the fourth embodiment, and is a diagram corresponding to FIG. 1 in the first embodiment. The negative electrode 1 according to the fourth embodiment is configured to further include a second porous film 7 in addition to the configuration shown in the third embodiment.

As shown in the figure, the negative electrode 1 includes a second porous film 7 between the anion conductive film 6 and the negative electrode active material layer 4. Like the first porous membrane 5, the second porous membrane 7 may be a member having ionic conductivity between the positive electrode 8 and the negative electrode 1, and is a first non-woven fabric made of polyolefin, filter paper, or the like. A member common to the porous membrane 5 can be used. The size and thickness of the second porous membrane 7 can also be the same as that of the first porous membrane 5.

Since the second porous membrane 7 has a porous structure, it can be arranged in the negative electrode case 2 to hold the electrolytic solution in the negative electrode case 2. In the metal-air battery 10 provided with such a negative electrode 1, the negative electrode active material layer 4 may expand or contract with the charge / discharge cycle, but the second porous film 7 is formed on the negative electrode active material layer 4. It is closely laminated and suppresses the shortage of the electrolytic solution of the negative electrode active material layer 4.

In addition, the second porous membrane 7 is interposed between the negative electrode active material layer 4 and the anionic conductive membrane 6 so as to be on the opposite side of the anionic conductive membrane 6 from the first porous membrane 5 side. It prevents the anion conductive film 6 from being damaged. Further, when the dendrite grows from the negative electrode active material layer 4 toward the positive electrode 8, the second porous film 7 acts as a buffer layer between the negative electrode active material layer 4 and the anion conductive film 6, and the dendrite acts as a buffer layer. Prevents the anion conductive film 6 from being damaged.

(Embodiment 5)
FIG. 8 is a cross-sectional view schematically showing the metal-air battery 10 according to the fifth embodiment. In the metal-air battery 10 according to the first embodiment, the positive electrode 81 for discharging is arranged on one side of the negative electrode 1, and the positive electrode 82 for charging is arranged on the other side. In the metal-air battery 10 according to this embodiment, the positive electrode 81 for discharging and the positive electrode 82 for charging are arranged adjacent to each other. The negative electrode 1 of the metal-air battery 10 includes the one having the configuration shown in the fourth embodiment.

As shown in FIG. 8, the positive electrode 8 constituting the metal-air battery 10 has a discharge positive electrode (air electrode) 81 which is a first positive electrode for discharge and a charging positive electrode 82 which is a second positive electrode for charging. And have. Both the positive electrode 81 for discharging and the positive electrode 82 for charging are arranged on both sides of the negative electrode 1. On one surface of the negative electrode case 2 of the negative electrode 1, a charging positive electrode 82 is arranged in contact with the opening 20, and a discharging positive electrode 81 is arranged adjacent to the charging positive electrode 82. A discharge positive electrode 81 is arranged on the inner surface of the battery case 9 in contact with the inside. The other surface of the negative electrode case 2 is similarly provided.

As a result, in the metal-air battery 10, the negative electrode 1 is provided substantially in the center between the two positive electrodes 81 for discharging, and the positive electrode 82 for charging is located between the positive electrode 81 for discharging and the negative electrode 1 (both sides of the negative electrode 1). It is configured to be provided in two places). The metal-air battery 10 has a structure capable of suppressing the growth of dendrites in the negative electrode 1 and preventing a short circuit between the electrodes.

Note that FIG. 8 shows a case where the negative electrode 1 in the metal-air battery 10 has the configuration shown in the fourth embodiment as an example, but the present invention is not limited to this, and the negative electrode 1 according to another embodiment is provided. May be good. Further, the metal air battery 10 has a configuration in which a discharge positive electrode 81 and a charging positive electrode 8 are provided on one side of the negative electrode 1 in the battery case 9, and the discharging positive electrode 81, the charging positive electrode 82, and the negative electrode 1 are provided in this order. Any arrangement may be made as long as it is arranged. Although not shown in FIG. 8, a separator for insulating the charging positive electrode 82 and the discharging positive electrode 81 may be provided between the charging positive electrode 82 and the discharging positive electrode 81.

(Embodiment 6)
FIG. 9 is a cross-sectional view schematically showing the metal-air battery 10 according to the sixth embodiment. The arrangement of the negative electrode 1, the discharge positive electrode 81, and the charging positive electrode 82 in the metal-air battery 10 is not limited to the above-mentioned form. The metal-air battery 10 according to this embodiment includes the negative electrode 1 having the configuration shown in the fourth embodiment, and has a positive electrode 81 for discharging on one side and a positive electrode 82 for charging on the other side of the negative electrode 1. Has been done.

As shown in FIG. 9, the negative electrode case 2 is provided with a first opening 21 and a second opening 22 on both sides of the negative electrode active material layer 4 in the thickness direction, respectively. The positive electrode 8 includes a discharge positive electrode 81 which is a first positive electrode and a charging positive electrode 82 which is a second positive electrode, and the discharge positive electrode 81 is arranged so as to face the first opening 21. The charging positive electrode 82 is arranged so as to face the opening 22 of 2.

Even with the metal-air battery 10 configured in this way, it is possible to suppress damage or breakage of the anionic conductive film that causes the growth of dendrites in the negative electrode 1, and it is possible to prevent a short circuit between the electrodes. Can be.

As described above, according to the negative electrode 1 and the metal-air battery 10 according to the present disclosure, since the first porous film 5 is provided in the negative electrode case 2 and used as a buffer layer of the anion conductive film 6, the anion conductive film 6 is damaged. Can be prevented from occurring. As a result, the negative electrode 1 and the metal-air battery 10 can prevent the generation of dendrite growth paths, prevent short circuits between the electrodes, and extend the life and output. ..

The present disclosure is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present disclosure.

The negative electrode and the metal-air battery according to the present disclosure can be widely used for the metal-air battery used as one of the power supply devices.

Claims (14)

A resin case with at least one opening,
A negative electrode current collector including a portion housed in the case and a portion extended from the case.
A negative electrode active material layer containing a negative electrode active material housed in the case and in contact with at least a part of the negative electrode current collector.
The first porous membrane covering the opening and
A negative electrode having an anionic conductive film arranged between the first porous film and the negative electrode active material layer. In the negative electrode according to claim 1,
The negative electrode is characterized in that the opening is covered with the first porous membrane inside the case. In the negative electrode according to claim 1 or 2,
A negative electrode characterized in that the case and the first porous membrane are welded together. In the negative electrode according to any one of claims 1 to 3, the negative electrode
The negative electrode is characterized in that the anion conductive film is in contact with the inner surface of the case. In the negative electrode according to any one of claims 1 to 4, the negative electrode
The negative electrode is characterized in that the anion conductive film is covered with the first porous film from the inside of the case and extends outward from the peripheral edge of the first porous film. In the negative electrode according to any one of claims 1 to 5, the negative electrode
The anion conductive film is a negative electrode characterized by containing a polymer containing an anion exchange group or a layered double hydroxide. In the negative electrode according to any one of claims 1 to 6, the negative electrode
The anion conductive film is a negative electrode characterized by suppressing the permeation of zincate ions and allowing the permeation of hydroxide ions. In the negative electrode according to any one of claims 1 to 7, the negative electrode
The first porous membrane is a negative electrode having an air permeability of 0.1 to 1000 seconds in terms of Garley value. In the negative electrode according to any one of claims 1 to 8, in the negative electrode.
A negative electrode characterized in that the first porous membrane has a large number of micropores having communication, and the average pore diameter of the micropores is 0.1 to 100 μm. In the negative electrode according to any one of claims 1 to 9, the negative electrode
A negative electrode characterized by providing a second porous film between the anion conductive film and the negative electrode active material layer. In the negative electrode according to any one of claims 1 to 10, the negative electrode
The negative electrode is characterized in that the case contains an electrolyte. A metal-air battery containing a negative electrode, a positive electrode, and an electrolyte.
The negative electrode is
A resin case with at least one opening,
A negative electrode current collector housed in the case and extended from the case,
A negative electrode active material layer containing a negative electrode active material housed in the case and in contact with at least a part of the negative electrode current collector.
The first porous membrane covering the opening and
The anion conductive film arranged between the first porous film and the negative electrode active material layer is provided.
A metal-air battery characterized in that the positive electrode is arranged so as to face the opening. In the metal-air battery according to claim 12,
The positive electrode includes a first positive electrode for discharging and a second positive electrode for charging.
A metal-air battery characterized in that the first positive electrode, the second positive electrode, and the negative electrode are arranged in this order. In the metal-air battery according to claim 12,
As the opening, a first opening and a second opening are provided on both sides of the negative electrode active material layer in the thickness direction, respectively.
The positive electrode includes a first positive electrode for discharging and a second positive electrode for charging.
A metal-air battery characterized in that the first positive electrode is arranged to face the first opening, and the second positive electrode is arranged to face the second opening.

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