JP2023107591A - Lithium air battery and oxygen flow path to be used therein - Google Patents

Abstract

To provide a lithium air battery which is enhanced in cycle characteristic by suppressing a squeeze effect and lightening the shortage of an amount of an electrolyte in a positive electrode layer while achieving a satisfying oxygen supply in an oxygen flow path.SOLUTION: A lithium air battery comprises: a negative electrode; a separator filled with a nonaqueous electrolyte; and a positive electrode having a positive electrode layer of a porous structure and an oxygen flow path for taking in oxygen as a positive electrode active material. As to the oxygen flow path, an oxygen flow path material that satisfies the following requirements is used: (1)the oxygen flow path material has a porosity of 60% or more; and (2)the oxygen flow path material has an electrolyte-repellent degree of 0.80 or more and 0.98 or less.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a lithium-air battery having a positive electrode provided with an oxygen channel for taking in oxygen as a positive electrode active material, and an oxygen channel used therein.

With the emergence of next-generation devices such as IoT and drone taxis, the demand for high-capacity, lightweight and compact batteries is increasing. Among various batteries, the lithium-air battery uses oxygen in the air as a positive electrode active material and lithium as a negative electrode active material, and is therefore expected as a secondary battery that meets these requirements.

As an example of a lithium-air battery, for example, in Patent Document 1, for the purpose of increasing the capacity of a lithium-air battery, a carbonaceous material having pores with a diameter of 1 nm or more and a pore volume of 1.0 ml/g or more is used for current collection. An air lithium battery comprising a positive electrode carried on a body surface, a negative electrode comprising a negative electrode active material, and a separator sandwiched between the positive electrode and the negative electrode and containing a non-aqueous electrolyte, wherein oxygen diffuses rapidly. For this purpose, a lithium-air battery using a porous material such as mesh, punched metal, or expanded metal as a current collector has been disclosed.

Patent Document 2 discloses a thin positive electrode structure in which a porous positive electrode material is joined to a plate-shaped positive electrode base material in order to realize the stacking of battery cells of a lithium-air battery and the increase in capacity due to the stacking. It discloses the use of a thin positive electrode structure in which grooves or holes for gas flow paths are formed in the positive electrode base material or the positive electrode material from one side to the opposite side. Further, in Patent Document 2, because of such a configuration, even if the thin positive electrode structure is laminated with the thin separator and the thin negative electrode structure, air or oxygen gas is formed from the grooves or holes communicated on the side surface. It is disclosed that the positive electrode active material can be supplied to the positive electrode material and reacted with the lithium ions contained in the electrolyte retained in the positive electrode material.

In Patent Document 3, a water-repellent film (a KOH aqueous solution is often used, and an electrolytic solution impregnated and held in zinc constituting the negative electrode is removed from the battery in a button-type air battery having a negative electrode filled with zinc. To provide an air battery and an assembled battery capable of reducing the internal resistance caused by a water-repellent film, etc., by taking a hint from a prior art document (Patent No. 3034110) disclosing the prevention of inadvertent leakage of In an air battery comprising a positive electrode layer, an electrolyte layer laminated on the positive electrode layer, and a negative electrode layer laminated on the electrolyte layer, It is disclosed to provide a conductive liquid-tight gas-permeable layer located on the opposite side of the electrolyte layer, and to provide an assembled battery including a plurality of such air cells. Further, in Patent Document 3, in the assembled battery, it is interposed between the conductive liquid-tight air-permeable layer of the first air battery and the negative electrode layer of the second air battery adjacent to the first air battery, It is disclosed that a channel is formed for circulating an oxygen-containing gas.

Patent Document 4 discloses a water-repellent membrane (functioning to prevent the electrolyte from leaking out of the battery) in a button-type air battery having a negative electrode filled with zinc and an electrolyte impregnated with zinc. Inspired by the prior art document (Japanese Patent Application Laid-Open No. 11-54130), realizing high output of air batteries by achieving both gas permeability and conductivity, electrode structures useful for series connection of air batteries The electrode structure includes a negative electrode current collector layer forming a negative electrode, a gas flow channel forming layer forming a gas flow channel for the positive electrode, and a liquid-tight ventilation layer forming the positive electrode. It has a structure in which a layer and a catalyst layer are laminated in order, the negative electrode collector layer, the gas channel forming layer, the liquid-tight ventilation layer and the catalyst layer are made of a material containing a conductive carbon material, and the negative electrode collector layer is It is disclosed that it has liquid repellency with respect to the electrolytic solution.

However, none of the above-mentioned documents describes or suggests how to achieve both a high porosity of the oxygen channel and suppression of the squeeze effect, which is a problem of the present invention to be described later. It is neither described nor suggested that the cycle characteristics of lithium-air batteries can be significantly degraded due to this undesirable squeeze effect even if the porosity is high.

JP-A-2002-015737 JP 2013-073765 A JP 2013-077548 A JP 2015-079592 A

It cannot be said that existing air batteries (including conventional stacked air batteries) have fully exploited the potential capabilities of such air batteries, such as miniaturization, weight reduction, and large capacity. There is a desire to improve capacity. One of the causes is the positive electrode (specifically, a structure composed of a positive electrode layer, an oxygen channel and a current collector). The oxygen channel is sometimes called an "oxygen channel structure" or an "oxygen channel layer", and the current collector is a current collector that constitutes the negative electrode (that is, a "negative electrode current collector"). In order to distinguish it intentionally, it is sometimes called a "positive current collector".
The present inventors focused on the squeeze effect as a factor that reduces the cycle performance of lithium-air batteries using a non-aqueous electrolyte. As used herein, the squeeze effect refers to the deposition of Li ₂ O ₂ on the positive electrode during the discharge reaction of the lithium-air battery, and the deposition volume of the non-aqueous electrolyte is pushed out to another location. The present inventors have found that such an undesirable squeeze effect occurs during the discharge reaction of the lithium-air battery, resulting in a shortage of the necessary electrolytic solution in the positive electrode layer (so-called "liquid depletion"), and eventually, lithium-air A hypothesis was constructed that the cycle characteristics of the battery deteriorated. This can be a particular problem even in stacked lithium-air batteries in which each stack unit has an oxygen channel. In particular, lithium-air secondary batteries designed for high energy density are designed to use as little non-aqueous electrolyte as possible to reduce weight. Due to the effect, the amount of electrolytic solution that is insufficient in the positive electrode layer becomes a problem. In addition, Li ₂ O ₂ precipitated in the oxygen channel due to the squeeze effect partially clogs the oxygen channel, resulting in a decrease in the transmittance of oxygen, which is the positive electrode active material. , a decrease in the capacity of the lithium-air battery, an increase in overvoltage, and the like may occur, resulting in significant deterioration of the cycle performance.
The present invention has been made to solve the above problems, and suppresses the squeeze effect to alleviate the shortage of the electrolyte in the positive electrode layer while realizing good oxygen supply in the oxygen channel. An object of the present invention is to provide a lithium-air battery with improved cycle characteristics.

The present inventors verified a gas diffusion layer (GDL) as an example of an oxygen channel suitable for weight reduction, and considering uniform and good oxygen supply from the cross section (side surface) of the GDL, the oxygen channel While seeking a certain high porosity in the material, we have extensively studied means for suppressing the squeeze effect and improving the cycle characteristics of the lithium-air battery. As a result, the non-aqueous electrolyte does not easily permeate the oxygen channel, and by applying electrolyte-repellent treatment, a small amount of the electrolyte moves to the oxygen channel as the lithium-air battery discharges. However, the present inventors have found that the undesirable squeeze effect can be suppressed by smoothly returning to the positive electrode layer during charging, thereby significantly improving the cycle characteristics of the lithium-air battery, thus completing the present invention.

That is, the gist of the present invention is as follows.
[1] A lithium-air battery comprising a negative electrode, a separator filled with a non-aqueous electrolyte, and a positive electrode,
The negative electrode includes a negative electrode active material layer containing lithium and a negative electrode current collector,
The positive electrode includes a positive electrode layer having a porous structure and an oxygen channel for taking in oxygen as a positive electrode active material,
A lithium-air battery using an oxygen channel material that satisfies the following conditions as the oxygen channel:
(1) the oxygen channel material has a porosity of 60% or more;
(2) The oxygen channel material has the following formula:
Degree of electrolyte repellency = 1 - [amount of non-aqueous electrolyte absorbed by oxygen channel material/amount of voids in oxygen channel material]
(However, the amount of the non-aqueous electrolyte absorbed by the oxygen channel material is the weight obtained by drying and weighing only the oxygen channel cut to a size of 15 × 15 mm in advance before configuring the air battery, and the weight of the oxygen channel. The oxygen channel was immersed in the non-aqueous electrolytic solution for 1 minute and then weighed. based on volume)
is 0.80 or more and 0.98 or less.
[2] The lithium-air battery according to [1], wherein the oxygen channel also functions as a positive electrode current collector, or the positive electrode further comprises a positive electrode current collector.
[3] The positive electrode is formed by laminating the positive electrode layer on both sides of the oxygen channel, and the negative electrode is formed by laminating the negative electrode active material layer on both sides of the negative electrode current collector, [1] or The lithium-air battery according to [2].
[4] The oxygen channel according to any one of [1] to [3].
[5] The oxygen channel according to any one of [1] to [4], the surface of which is coated with an organic compound having electrolyte repellency.

By using the oxygen channel exhibiting electrolyte repellency of the present invention as a component of the positive electrode, performance deterioration due to the squeeze effect of the electrolyte is suppressed in a lithium-air secondary battery designed for high energy density, and cycle characteristics are excellent. A high energy density lithium-air battery can be realized.
Further, by using the oxygen channel material of the present invention exhibiting electrolyte repellency and electrical conductivity for the oxygen channel of the positive electrode, it is possible to design a structure in which the weight of the layer unit on the positive electrode side is reduced. It is possible to realize a lithium-air battery with improved cycle characteristics by suppressing the squeeze effect and alleviating the shortage of the amount of electrolytic solution in the positive electrode layer while realizing good oxygen supply in the oxygen channel.

1 is a schematic cross-sectional view showing the structure of a lithium-air battery that is an embodiment of the present invention; FIG. 1 is a schematic cross-sectional view showing the structure of a lithium-air battery that is an embodiment of the present invention; FIG. 1 is a schematic cross-sectional view showing the structure of a laminated lithium-air battery that is an embodiment of the present invention. FIG.

An example of a preferred mode for carrying out the present invention will be described below. However, the following embodiments are examples for explaining the present invention, and the present invention is not limited to the following embodiments.

<Oxygen channel>
The oxygen channel has a function as an oxygen channel through which oxygen can permeate and a function as a positive electrode current collector (oxygen channel/positive electrode current collector). In addition, the function of the oxygen channel and the function of the current collector may be separated from each other. That is, the oxygen channel and the current collector (positive electrode current collector) may be provided independently.
In the examples described later, a carbon-based gas diffusion layer (GDL), which is sometimes used for the gas diffusion layer of a fuel cell, was used as the oxygen channel and positive electrode current collector. And it is not necessarily limited to carbon-based GDL as long as it has a current collecting function, and metal meshes such as stainless steel, aluminum, and nickel, polyester, polyimide, tetrafluoroethylene, etc. Polymer porous bodies and meshes can be used. good too.

A lithium-air battery can be configured by using an oxygen channel material that satisfies the following conditions for the oxygen channel. i.e.
(1) the oxygen channel material has a porosity of 60% or more;
(2) The oxygen channel material has the following formula:
Degree of electrolyte repellency = 1 - [amount of non-aqueous electrolyte absorbed by oxygen channel material/amount of voids in oxygen channel material]
(However, the amount of the non-aqueous electrolyte absorbed by the oxygen channel material is the weight obtained by drying and weighing only the oxygen channel cut to a size of 15 × 15 mm in advance before configuring the air battery, and the weight of the oxygen channel. The oxygen channel was immersed in the non-aqueous electrolytic solution for 1 minute and then weighed. based on volume)
is 0.80 or more and 0.98 or less.
In the examples described later, an oxygen channel material that satisfies the above condition (1) was used, the electrolyte repellent treatment described below was performed so as to satisfy the above condition (2), and a piece of 25 mm×20 mm was cut out and used. .
Regarding the condition (1) above, the porosity of the oxygen channel material is preferably 60% or more, more preferably 80% or more, preferably 95% or less, and more preferably 90% or less. . By making it equal to or higher than the above lower limit value, it is possible to secure the oxygen supply amount and contribute to good continuous charging and discharging as an air battery. Moreover, by making it below the said upper limit, intensity|strength can be ensured and it can contribute to stable maintenance of a porous structure.
Regarding the above condition (2), the degree of electrolyte repellency is preferably 0.80 or more, more preferably 0.90 or more, preferably 0.98 or less, and more preferably 0.96 or less. . If the degree of electrolyte repellency is too low, cycle characteristics will be deteriorated due to an unfavorable squeeze effect, which is not preferable. In addition, if the degree of electrolyte repellency is too high, when the electrolyte leaks out due to discharge, the leaked electrolyte cannot be absorbed at all or hardly in the oxygen channel, and the electrolyte leaked out to the periphery of the outside is not absorbed. It is not preferable because it cannot return and the cycle characteristics deteriorate.

<Method of Electrolyte Repellent Treatment (Method of Manufacturing Oxygen Channel)>
The method of the electro-repellent treatment is not particularly limited as long as it is a method effective for achieving a predetermined degree of electro-repellent liquid repellency. and a method of adjusting the electrolyte repellency. Organic compounds having electrolyte repellency include polytetrafluoroethylene (PTFE), tetrafluoroethylene/hexafluoropropylene copolymer (FEP), tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene solutions or dispersions of fluorinated organic polymers such as ethylene/ethylene copolymer (ETFE), perfluoropolyether group-containing silane coupling agents and fluorine-substituted linear alkylsilanes such as perfluorooctyltriethoxysilane; Silane cups such as methylsilanes, methyl-siloxanylsilanes, linear alkylsilanes with 2 to 32 carbon atoms, branched and cyclic alkylsilanes, phenyl-phenylalkylsilanes, substituted phenyl-phenylalkylsilanes, naphthylsilanes, dialkylsilanes, etc. Ring agents, hexamethyldisilazane, dimethyl silicone, commercially available fluorine-based antifouling/waterproof/moisture-proof coating agents (Optool, Optoace, etc. manufactured by Daikin Industries, Ltd.) can be used alone or in combination of two or more. can.
The treatment conditions for the electrolyte repellent treatment vary depending on the organic compound used, but are not particularly limited as long as the conditions are effective for achieving a predetermined degree of electrolyte repellency.

<Method for measuring degree of electrolyte repellency>
The method for measuring the degree of electrolyte repellency is as follows. First, the oxygen channel material is cut into a size of 15×15 mm, dried sufficiently, and then weighed. Next, the oxygen channel material is completely immersed in a petri dish in which the electrolyte has been immersed, and after 1 minute, the oxygen channel material is pulled out, the electrolyte on the surface is wiped off, and the material is weighed again. In this way
1-[Amount of non-aqueous electrolyte absorbed by oxygen channel material/void volume of oxygen channel material]
The degree of electrolyte repellency defined by was calculated. That is, the amount of the non-aqueous electrolyte absorbed by the oxygen channel material is calculated by the weight obtained by drying and weighing only the oxygen channel cut to a size of 15 × 15 mm in advance before constructing the air battery, and the weight of the oxygen channel. It is calculated based on the difference between the weight of the channel immersed in the non-aqueous electrolyte solution for 1 minute and weighed, and the void volume of the oxygen channel is equal to the void volume of the oxygen channel before forming the air battery. It is based on

<Structure of Lithium Air Battery>
1 and 2 are cross-sectional schematic diagrams showing the structure of a lithium-air battery according to an embodiment of the present invention. FIG. 2 is the same as FIG. 1 except that solid electrolyte (layer) 108 is not used in FIG.
The lithium-air batteries 100 and 200 consist of a laminated structure in which a positive electrode 101 and a negative electrode 104 are laminated with a non-aqueous electrolyte layer 107 (a separator filled with a non-aqueous electrolytic solution) interposed therebetween.
The non-aqueous electrolyte layer 107 may not further include a solid electrolyte (layer) 108, as shown in FIG. 2, other than the form shown in FIG. , or may consist of a single separator. This laminated structure is restrained by the glass plate 110 and the stainless steel plate 111 via springs 115 .

Positive electrode (air electrode) 101
A positive electrode (air electrode) 101 is composed of a positive electrode layer 102 and an oxygen channel/positive current collector 103 . The positive electrode (air electrode) 101 may further include a positive electrode lead (not shown).

Oxygen channel/positive current collector 103
The oxygen channel/positive current collector 103 has a function as an oxygen channel through which oxygen as a positive electrode active material can pass and a function as a current collector. The oxygen channel/positive current collector 103 may have a function as an oxygen channel and a function as a current collector separately. That is, the oxygen channel and the positive electrode current collector may be provided independently.
Using a carbon-based material (e.g., carbon paper (TGP-060, manufactured by Toray Industries, Inc.)) that is sometimes used for the gas diffusion layer (GDL) of fuel cells as an oxygen channel and positive electrode current collector, Electrolytic repellent treatment can be performed, but it is not necessarily limited to carbon paper as long as it can permeate oxygen and has a current collecting function. Examples include tungsten (W), aluminum (Al), and nickel. (Ni), titanium (Ti), gold (Au), silver (Ag), platinum (Pt), a mesh having a metal selected from the group of palladium (Pd), etc. may be used, and insulation such as polyester and polyimide may be used. A conductive mesh obtained by nickel-plating a polyester mesh and the like may be used in combination with a flexible polymer porous material.
A lithium-air battery can be configured by using an oxygen channel material that satisfies the following conditions for the oxygen channel/positive electrode current collector 103 . i.e.
(1) the oxygen channel material has a porosity of 60% or more;
(2) The oxygen channel material has the following formula:
Degree of electrolyte repellency = 1 - [amount of non-aqueous electrolyte absorbed by oxygen channel material/amount of voids in oxygen channel material]
(However, the amount of the non-aqueous electrolyte absorbed by the oxygen channel material is the weight obtained by drying and weighing only the oxygen channel cut to a size of 15 × 15 mm in advance before configuring the air battery, and the weight of the oxygen channel. The oxygen channel was immersed in the non-aqueous electrolytic solution for 1 minute and then weighed. based on volume)
is 0.80 or more and 0.98 or less.
The oxygen channel material used for the oxygen channel, the method of the electrolyte repellent treatment, and the method of measuring the degree of electrolyte repellency are as described above.

Positive electrode layer (air electrode layer) 102
The positive electrode layer (air electrode layer) 102 must be conductive and have a porous structure. Examples of materials for the positive electrode layer include carbon, metals, carbides, oxides, and the like. Carbon is preferred, and a positive electrode including a positive electrode layer having a porous structure mainly composed of a carbon substance can be suitably used. The positive electrode layer (air electrode layer) having a porous structure serves as a reaction field in which lithium peroxide generated by the discharge reaction is deposited.
The positive electrode layer 102, that is, the air electrode layer having a porous structure, is, for example, a material mixing step (mixture slurry preparation step), a sheet molding step (molding step), a solvent immersion step, a drying step, and a firing step (non-melting step). , which may be a two-step heat treatment process consisting of a carbonization process).

In the method of manufacturing the positive electrode layer (air electrode layer) 102 , the material mixing step (mixture slurry preparation step) includes, for example, 50% to 80% by weight of porous carbon particles and 1% to 15% by weight of carbon fibers. , The polymer material for binding is weighed so as to be 5% by weight or more and 49% by weight or less, and in order to uniformly disperse them, a solvent consisting of N-methylpyrrolidone is used to apply a mixture paint ( It is a step of preparing a mixture slurry).
Here, as the porous carbon particles, as described above, carbon black including Ketjenblack (registered trademark), other carbon particles formed by a template method, and the like can be used.
As carbon fibers, for example, carbon fibers having a fiber diameter of 0.1 μm or more and 20 μm or less and a length of 1 mm or more and 20 mm or less can be used.
For example, polyacrylonitrile (PAN) and polyvinylidene fluoride can be used as the binding polymer material.
Examples of solvents that can be used include N-methylpyrrolidone, dimethylsulfoxide (DMSO), dimethylformamide (DMF), dimethylacetamide (DMA), and the like.

The sheet molding step is a step of molding the mixture paint (mixture slurry). The sheet forming method is not particularly limited, and for example, a wet film forming method using a known doctor blade or the like can be mentioned. In addition, a roll coater method, a die coater method, a spin coat method, a spray coating method, and the like can also be used. The shape after molding can be various shapes depending on the purpose.

The solvent immersion step is a step of forming a porous film by immersing the sample (sheet) formed in the sheet forming step in a solvent having low solubility for the binding polymer material by a non-solvent induced phase separation method. Examples of solvents used in the solvent immersion step include water, alcohols such as ethyl alcohol (ethanol), methyl alcohol (methanol), isopropyl alcohol (isopropanol), and mixed solvents thereof.

The drying step is a step of volatilizing various solvents from the sample. Examples of the drying method include a method of placing in a dry air environment, a reduced pressure drying method, a vacuum drying method, and the like. In this drying step, heating may be performed at a temperature exceeding the boiling point of the solvent in order to increase the drying speed.

The baking step is a step of baking the sample (sheet) after the drying step. The baking treatment can be performed using, for example, an oven furnace, infrared irradiation, a baking furnace, or the like.
Here, the firing process can be a one-time heat treatment, but can also be a two-step heat treatment of infusibilization and firing. Than. The heat treatment temperature for firing is preferably 800° C. or more and 1400° C. or less, and the atmosphere at that time is preferably an inert atmosphere such as argon (Ar) gas or nitrogen (N ₂ ) gas.
For example, when PAN is used as the binding polymer, heat treatment is performed in the air at _about 300°C to make it infusible. It is preferable to perform the following heat treatment.

Through the above steps, the positive electrode layer 102 (air electrode layer) having mechanical strength sufficient for self-supporting and practical use is manufactured. The positive electrode layer 102 (air electrode layer) is self-supporting and has high air permeability, high ion transport efficiency, and a wide reaction field.

negative electrode 104
The negative electrode 104 should include a negative electrode active material layer containing lithium, and may further include a current collector. As the negative electrode 104, for example, a structure including a negative electrode current collector 106 and a negative electrode active material layer 105 containing lithium thereon can be given. As the negative electrode active material layer 105, a material made of a metal or an alloy that absorbs and releases lithium can be used, and lithium metal can be typically used. As the negative electrode current collector 106, for example, copper foil can be used.
Non-aqueous electrolyte layer 107

A non-aqueous electrolyte layer 107 is arranged between the positive electrode (air electrode) 101 and the negative electrode 104 .
The non-aqueous electrolyte layer may consist of only one separator, may contain one or more separators, may contain two or more separators, and may further contain a solid electrolyte (layer). As an example, the nonaqueous electrolyte layer 107 is composed of a solid electrolyte (layer) 108 and a separator 109 . In one embodiment, the non-aqueous electrolyte layer includes two or more separators with a layer of solid electrolyte between the separators. In another embodiment, a layer of solid electrolyte is formed over one or more separators. In yet another embodiment, the outer edge of the separator is outside the outer edges of the positive electrode layer and the negative electrode active material layer, and the outer edge of the solid electrolyte layer is substantially equal to or greater than the outer edge of the separator. outside. In this way, by adopting a configuration in which the non-aqueous electrolyte layer includes the separator and the solid electrolyte (layer) in a specific positional relationship, the positive electrode-side non-aqueous electrolyte and the negative electrode-side non-aqueous electrolyte move through the separator. can be suppressed.
Separator 109

The separator 109 is made of an insulating material that allows lithium ions to pass through, has a porous structure, and does not have reactivity with the positive electrode layer (air electrode layer) 102, the negative electrode active material layer 105, and the electrolytic solution. Any inorganic or organic material is applied. Moreover, the separator 109 also plays a role of retaining the electrolyte. If this condition is satisfied, there is no particular limitation, and separators used in existing metal batteries can be used. For example, the separator 109 is selected from the group consisting of a porous film (for example, heat-melting microporous film) made of synthetic resin such as polyethylene, polypropylene, polyolefin, glass fiber, and non-woven fabric.
In order to prevent a short circuit between the positive electrode (air electrode) 101 and the negative electrode 104, the separator 109 preferably has a size larger than each active material layer.

Solid electrolyte (layer) 108
Optionally, a solid electrolyte or solid electrolyte layer 108 may be provided. The solid electrolyte or solid electrolyte layer 108 should be a dense structure capable of selectively permeating lithium ions, reliably blocking other components, and having no reactivity with the non-aqueous electrolyte. is necessary. As long as this condition is satisfied, the solid electrolyte or solid electrolyte layer 108 is not particularly limited, and existing oxide-based solid electrolytes, sulfide-based solid electrolytes, and polymer-based solid electrolytes can be applied. Considering the impermeability of the electrolytic solution and the reactivity with the non-aqueous electrolytic solution, an oxide-based solid electrolyte is preferable. For example, the solid electrolyte (layer) 108 includes Li _1+x+y Al _x Ti _2-x Si _y P _3-y O ₁₂ , Li _1.5 Al _0.5 Ge _1.5 P ₃ O ₁₂ (LAGP), La _{0 .55} Li _0.33 TiO ₃ , Li ₇ La ₃ Zr ₂ O ₁₂ and the like.

The solid electrolyte layer 108 may be placed between two separators, or a solid electrolyte (layer) may be formed on the separator by coating solid electrolyte particles on the separator. .
Solid electrolyte layer 108 preferably has the same size as separator 109 or a size larger than separator 109 in order to prevent the positive electrode side non-aqueous electrolyte solution and the negative electrode side non-aqueous electrolyte solution from moving through the separator.
The solid electrolyte layer is not essential, and one of the solid electrolyte layer 108 and the separator 109 can be omitted.

Electrolyte As the electrolyte, any non-aqueous electrolyte containing a lithium metal salt is preferable. When a lithium salt is used as the lithium metal salt in the non-aqueous electrolytic solution (or non-aqueous electrolytic solution), for example, Li(CF ₃ SO ₂ ) ₂ N (LiTFSI), LiNO ₃ , LiBr, LiPF ₆ , LiBF ₄ , _LiSbF6 , _{LiSiF6 , LiAsF6} , _LiN ( _SO2C2F5 ) ₂ , Li( _{FSO2 ) 2N} , _LiCF3SO3 (LiTfO), _{LiC4F9SO3 , LiClO4 ,} LiAlO2 _, Lithium salts such as LiAlCl ₄ , LiB(C ₂ O ₄ ) ₂ may be mentioned. Among them, in the case of a lithium-air secondary battery, an electrolytic solution containing LiBr is particularly preferable as the lithium salt.
In the non-aqueous electrolytic solution, the non-aqueous solvent includes glymes (monoglyme, diglyme, triglyme, tetraglyme), methyl butyl ether, diethyl ether, ethyl butyl ether, dibutyl ether, polyethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, cyclohexanone, dioxane, Dimethoxyethane, 2-methyltetrahydrofuran, 2,2-dimethyltetrahydrofuran, 2,5-dimethyltetrahydrofuran, tetrahydrofuran, methyl acetate, ethyl acetate, n-propyl acetate, dimethyl acetate, methyl propionate, ethyl propionate, methyl formate , ethyl formate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, ethylene carbonate, propylene carbonate, butylene carbonate, polyethylene carbonate, γ-butyrolactone, decanolide, valerolactone, mevalonolactone, caprolactone , acetonitrile, benzonitrile, nitromethane, nitrobenzene, triethylamine, triphenylamine, tetraethylene glycol diamine, dimethylformamide (DMF), diethylformamide, N-methylpyrrolidone, dimethylsulfone, tetramethylene sulfone, triethylphosphine oxide, 1,3- selected from, but not limited to, the group consisting of dioxolane and sulfolane; These solvents may be used alone, or two or more of them may be mixed and used.
Through the solid electrolyte (layer) 108, the positive electrode side non-aqueous electrolytic solution and the negative electrode side non-aqueous electrolytic solution may have the same composition or may have different compositions.

Other Configurations Other configurations of the lithium-air batteries 100 and 200 shown in FIGS. 1 and 2 will be described.
In the lithium-air batteries 100 and 200, the positive electrode layer 102 and the negative electrode active material layer 105 have a square shape, and include a glass plate 110, a stainless steel plate 111, a fixing screw 112, a fixing washer 113, a column 114, a spring 115, and a spacer 116. I have.
Four corners of the lower stainless steel plate 111 are preliminarily joined to four columnar supports 114, and the upper stainless steel plate 111 has holes through which the supports 114 pass. is open.

The positive electrode 101, the non-aqueous electrolyte layer 107, the negative electrode 104, and the two glass plates 110 are sandwiched between two stainless steel plates 111 from above and below. It is passed through and sandwiched. A spacer 116 , a spring 115 , and a fixing washer 113 are passed through a post 114 penetrating through a hole in the upper stainless steel plate 111 . The post 114 is threaded and fixed with a fixing screw 112 , and the pressure applied between the stainless steel plates 111 can be controlled by the tightening degree of the fixing screw 112 .

The glass plate 110 functions as an insulator that prevents the positive electrode 101 and the negative electrode 104 from short-circuiting through the stainless plate 111 and the struts 114 .

<Structure of stacked lithium-air battery>
FIG. 3 is a schematic cross-sectional view showing the structure of a laminated lithium-air battery according to an embodiment of the present invention. A laminated lithium-air battery 300 has a laminated structure in which a positive electrode structure 101 and a negative electrode structure 104 are laminated with a separator 109 interposed therebetween. The number of laminations may be one or more pairs in units of one positive electrode structure 101 and one negative electrode structure 104, and there is no particular upper limit to the number of pairs. Here, the negative electrode structure 104 has a structure in which the negative electrode active material layers 105 are arranged one above the other with the negative electrode current collector 106 interposed therebetween. The positive electrode layer 102 is sandwiched between them and arranged vertically. The fact that a battery with a larger capacity can be constructed with such a simple laminated structure is a unique feature of a positive electrode structure having self-supporting porous carbon particles. Examples of the negative electrode current collector 106 include copper (Cu), tungsten (W), nickel (Ni), titanium (Ti), gold (Au), silver (Ag), platinum (Pt), and palladium (Pd). Mention may be made of electrodes comprising metals selected from the group. Since the oxygen channel/positive current collector 103 also serves as an oxygen channel, carbon paper, tungsten (W), aluminum (Al), nickel (Ni), titanium (Ti), gold (Au), silver (Ag), A mesh containing a metal selected from the group of platinum (Pt) and palladium (Pd) may be used, and an insulating polymeric porous material such as polyester or polyimide and a polyester mesh nickel-plated conductive mesh may be used in combination. can do. Note that the laminated structure is housed in a container (not shown) filled with oxygen. In the laminated lithium-air battery 300, the positive electrode structure 101 has high air or oxygen permeability and can take in a large amount of oxygen, has both high ion transport efficiency and a wide reaction field, and is compact. Since it can be made smaller and has a simple structure, it can be made smaller and lighter, making it an air battery suitable for increasing capacity.

<Method for manufacturing lithium-air battery>
An example of a method for manufacturing the lithium-air batteries 100 to 200 will be described.

The method for manufacturing the positive electrode layer (air electrode layer) 102 is as described above.
The oxygen channel material used for the oxygen channel/positive electrode current collector 103, the method of the electrolyte repellent treatment, and the method of measuring the degree of electrolyte repellency are as described above.

The negative electrode 104 is prepared and manufactured, for example, as follows. That is, on the negative electrode current collector 106 cut into a rectangular shape, a square negative electrode active material layer 105 made of lithium or the like having the same length as the short side of the negative electrode current collector 106 is prepared and stacked so as to overlap. , to obtain the negative electrode 104 .

Next, a separator 109 is placed on the negative electrode active material layer 105, and the separator 109 is filled with a predetermined amount of non-aqueous electrolytic solution.
Although only one separator may be used, optionally, as shown in FIG. The separators 109 may be stacked so that the centers of the square shapes overlap each other, and the separator 109 may be filled with a predetermined amount of the non-aqueous electrolytic solution. Also, optionally, a further separator 109 may be placed above the separator 109, as shown in FIG. The member made of or containing a separator can function as a non-aqueous electrolyte layer.

Next, the positive electrode layer 102 may be placed on the separator 109 so that the centers of the square shapes overlap each other, and the positive electrode layer 102 may be filled with a predetermined amount of non-aqueous electrolytic solution.

After that, the oxygen channel/positive current collector 103 (to which a positive electrode lead (not shown) may be attached in advance) is laminated so as to overlap three sides of the positive electrode layer 102 . At this time, in order to suppress short-circuiting between the positive electrode and the negative electrode, it is preferable to take out a portion that does not overlap with the positive electrode layer 102 (for example, one side where the positive electrode lead is attached) in the direction opposite to the negative electrode current collector 106 .

Next, a laminate composed of the positive electrode 101, the negative electrode 104, and the non-aqueous electrolyte layer 107 (which may be made of only the separator) is restrained by the glass plate 110 and the stainless steel plate 111 using the springs 115 and the spacers 116. It is fixed with a washer 113 and a fixing screw 112 . At this time, the fixing screws are adjusted so that a pressure of 13 to 14 N/cm ² is applied to the positive electrode 101, the negative electrode 104 and the non-aqueous electrolyte layer 107. FIG.

Through the above steps, the lithium-air battery 100 is obtained. Here, it is preferable to assemble the lithium-air battery under dry air, for example, under dry air with a dew point temperature of −50° C. or lower.
When manufacturing the lithium-air battery 200, it may be assembled in the same manner as the lithium-air battery 100 except that the solid electrolyte layer 108 is not included in the above steps.

<Measurement method for charge/discharge characteristics and charge/discharge cycle measurement of lithium-air battery>
A method for measuring charge/discharge characteristics and charge/discharge cycle characteristics of a lithium-air battery will be described.
To evaluate the charge-discharge cycle characteristics, a charge-discharge evaluation device (TOSCAT-3100) manufactured by Toyo System Co., Ltd. was used.
The charging condition is that the applied current is a current density of 0.2 mA/cm ² per electrode area (0.8 mA for a cell with 4 cm ² electrodes), and charging can be performed until a predetermined cut-off voltage is reached. The upper limit of the charging cutoff voltage of the present invention is preferably 4.0V, and the lower limit is preferably 3.7V.
On the other hand, the discharge conditions were such that the applied current was a current density of 0.4 mA/cm ² per electrode area (1.6 mA for a cell with 4 cm ² electrodes) for 10 hours or until a cutoff voltage of 2.0 V was reached. , until the discharge capacity became 80% or less of the initial discharge capacity. That is, when the discharge capacity fell below 80% of the initial discharge capacity at the N+1th discharge, the number of cycles of the cell was defined as N times.

EXAMPLES The production and characteristics of the lithium-air battery of the present invention will be described in more detail below based on examples. These descriptions are examples of embodiments of the present invention, and the present invention is not limited to these examples.

[Example 1]
Using Carbon Paper JNT 21 (manufactured by MFC Technology Co., Ltd.) coated with 10% PTFE for the oxygen channel and positive electrode current collector, a lithium-air secondary battery was produced in the following manner, and the charge-discharge cycle characteristics were measured. etc. were measured. Table 1 shows the results.

Oxygen channel/positive current collector 103
For the oxygen channel/positive current collector 103, Carbon Paper JNT 21 (manufactured by MFC Technology Co., Ltd.) coated with 10% polytetrafluoroethylene (PTFE) is used as a carbon-based gas diffusion layer (GDL). board. The formula below:
Degree of electrolyte repellency = 1 - [amount of non-aqueous electrolyte absorbed by oxygen channel material/amount of voids in oxygen channel material]
(However, the amount of the non-aqueous electrolyte absorbed by the oxygen channel material is the weight obtained by drying and weighing only the oxygen channel cut to a size of 15 × 15 mm in advance before configuring the air battery, and the weight of the oxygen channel. The oxygen channel was immersed in the non-aqueous electrolytic solution for 1 minute and then weighed. based on volume)
When the degree of electrolyte repellency of the oxygen channel material defined in Table 1 was measured, it was 0.96. This oxygen channel material was cut into a size of 25 mm×20 mm and used as the oxygen channel/positive current collector 103 .

Positive electrode layer 102
(Mixture slurry preparation process)
75 parts by mass of Ketjenblack EC600JD as porous carbon particles, 10 parts by mass of carbon fiber, 15 parts by mass of polyacrylonitrile (PAN) as a polymeric binder material, and N-methylpyrrolidone as a solvent for uniformly dispersing them. was added and mixed with a rotating/revolving kneader ARE310 manufactured by Thinky to prepare a mixture slurry. Carbon fibers having an average fiber diameter of 6 μm and an average length of 3 mm were used.

(Molding process)
The mixture slurry was molded into a sheet having a thickness of 300 μm by a wet film forming method using a doctor blade.

(Solvent immersion step)
The molded sheet was placed in a tray, 220 g of methanol was added, and the tray was allowed to stand. After 2 hours, the methanol in the tray was discharged, 220 g of methanol was newly added, and after standing still for 17 hours, the methanol in the tray was discharged.
In Example 1, the above molded sheet in which the porous carbon particles and carbon fibers were dispersed in an N-methylpyrrolidone solution of PAN was immersed in methanol, which is a non-solvent (poor solvent), so that PAN was converted to carbon. Particles and carbon fibers were phase-separated and precipitated in a bound state to form a porous film with carbon particles as a skeleton, and most of N-methylpyrrolidone was compatible with methanol.
(Drying process)
The porous membrane was taken out from the tray and dried at 50° C. for 2 hours and at 80° C. for 10 hours to remove the volatile solvent contained in the porous membrane.

(Infusibilization step)
The dried porous membrane was subjected to an infusible heat treatment at 320° C. for 3 hours in an air circulation atmosphere to convert PAN in the dried porous membrane into an infusible resin.

(Carbonization process)
An infusible porous film having a length of 90 mm and a width of 80 mm obtained by the infusible treatment was heated at a rate of 10° C./min using a box-type furnace manufactured by Denken High Dental Co., while flowing nitrogen gas at a rate of 600 mL/min. The temperature was raised to 1050° C., held at 1050° C. for 3 hours, and then allowed to cool to room temperature, thereby carbonizing the infusibilized PAN and obtaining a porous carbon film composed entirely of carbon. The average thickness of the film was 170 μm, and the average basis weight per unit area was 3 mg/cm ² . A positive electrode layer 102 was obtained by cutting a 20 mm square shape from this porous carbon film.
One of the obtained positive electrode layers was immersed in a petri dish having a diameter of 40 mm containing 1 ml of the electrolytic solution, and after vacuum impregnation for 15 minutes, the electrolytic solution remaining on the surface was wiped off with Kimtowel. It was 14.5 mg/cm ² . From the specific gravity (1.12) of the electrolytic solution used, the maximum filling amount (volume at which the electrolytic solution filling amount is 100%) was calculated. The calculated maximum fill volume was 13.0 μL/cm ² .

negative electrode 104
The negative electrode current collector 106 was obtained by cutting a copper foil having a thickness of 18 μm into a shape of 60 mm×20 mm. A lithium foil having a thickness of 100 μm was cut into a shape of 20 mm×20 mm for the negative electrode active material layer 105 . Then, a 20 mm square lithium foil cut out was pasted so that three sides thereof overlapped with three sides of the negative electrode current collector 106, whereby the negative electrode 104 was obtained.

Non-aqueous electrolyte The non-aqueous electrolyte is 0.5 mol/L Li(CF ₃ SO ₂ ) ₂ N (LiTFSI), 0.5 mol/L LiNO ₃ and 0.2 mol/L LiBr. was obtained by dissolving in tetraglyme (tetraethylene glycol dimethyl ether) solvent.

Solid electrolyte (layer) 108
For the solid electrolyte layer, NASICON-type Li _1+x+y Al _x (Ti, Ge) _2-x Si _y P _3-y O ₁₂ (solid electrolyte LICGC ^TM AG-01 manufactured by Ohara Co., Ltd.) having a size of 22 mm×22 mm and a thickness of 180 μm was used. Using.

Separator 109
As the separator 109, a 22 mm square polyethylene microporous film (20 μm thick) manufactured by W-SCOPE was used.

Lithium air battery (lithium air secondary battery) 100
The production (assembly) of the lithium-air secondary battery 100 was performed under dry air with a dew point temperature of -50°C or lower. A separator 109 was placed on the negative electrode active material layer 105 of the negative electrode 104, and the separator 109 was filled with 10 μL (2.5 μL/cm ² ) of the non-aqueous electrolytic solution.
Furthermore, on the separator, a solid electrolyte layer 108 (solid electrolyte LICGC ^TM AG-01 manufactured by Ohara Co., Ltd. (NASICON type Li _1+x+y Al _x (Ti, Ge) _2-x Si _y P _3-y O ₁₂ ) (22 mm x 22 mm , thickness 180 μm) and a separator for the positive electrode were arranged.The amount of liquid injected was 70% of the maximum filling amount of the positive electrode (the volume where the filling amount of the electrolyte solution is 100%).This amount of liquid injected is 1 cm ² of the positive electrode Since the positive electrode of 20 mm square was used, the amount of liquid injected for the entire positive electrode was 36.3 μL.First, one positive electrode prepared by the above method and the tetra A petri dish (φ30 mm depth 10 mm) containing 0.2 mL of glyme (TEGDME) solvent was placed, and the pressure in the chamber was reduced to 1.3 Pa by a direct-coupled oil rotary vacuum pump.Then, the chamber was heated to 70°C. After holding for 30 minutes, the inside of the chamber was returned to the air, and the positive electrode was taken out.As a result of measuring the weight of the positive electrode before and after gas phase adsorption, the adsorption capacity of the electrolyte solvent to the positive electrode at this time was 1.3 μL/cm ² . Next, for one positive electrode, a PTFE type membrane filter (manufactured by Advantec Toyo Co., Ltd., diameter 90 mm, hole diameter 1 μm) cut into 22 mm squares was used as a member containing the electrolyte (electrolyte transfer member). are prepared, and the electrolytic solution is measured with a micropipette so as to be 3.8 μL/cm ² (18.1 μL per electrolytic solution transfer member) for each electrolytic solution transfer member, and the electrolytic solution The electrolytic solution was transferred by standing at room temperature and atmospheric pressure for 3 minutes, after which the electrolytic solution transfer member was removed, and the weight of the injected positive electrode was measured to contain 70% of the positive electrode. After stacking the injected positive electrode layers so that the center of the square overlaps, and stacking the oxygen channel so that it overlaps with three sides of the positive electrode layer, the positive electrode lead (SHS_430 stainless steel mesh made by Asadamesh/ 13) was attached.The laminate was restrained by a glass plate 110 and a stainless steel plate 111 with a spring 115 interposed therebetween, and fixed by a fixing washer 113 and a fixing screw 112. At this time, the positive electrode 101, the negative electrode 104 and the A fixing screw 112 was adjusted so that a pressure of 13 to 14 N/cm ² was applied to the separator 109 to obtain a lithium-air secondary battery 100 .
Although this lithium-air secondary battery 100 is a single-layer cell, it is sandwiched between glass plates 110 to limit the oxygen intake surface to the cross section (side surface) of the oxygen channel/positive electrode current collector 103 .

<Measurement and measurement results>
The discharge capacity was measured using a charge/discharge evaluation device (TOSCAT-3100, manufactured by Toyo System Co., Ltd.). The discharge conditions were such that the applied current was a current density of 0.4 mA/cm ² per electrode area (1.6 mA for a cell with 4 cm ² electrodes), and the discharge was continued until a cutoff voltage of 2.0 V was reached. capacity.
As shown in Table 1, in Example 1, the porosity and electrolyte repellency of the oxygen channel material were 88.4% and 0.96, respectively. The number of cycles capable of repeating 80% of the set capacity (the same applies hereinafter) was 12 times.

[Comparative Example 1]
In Example 1, Carbon Paper JNT 21 (manufactured by MFC Technology Co., Ltd.), which was not subjected to electrorepellent treatment and was not subjected to PTFE coating treatment, was used as the oxygen channel/positive current collector. A lithium-air secondary battery was produced in the same manner, and the charge-discharge cycle characteristics and the like were measured. Table 1 shows the results.
As shown in Table 1, in Comparative Example 1, the porosity and electrolyte repellency of the oxygen channel material were 89.5% and 0.58, respectively. , twice.

[Example 2]
In Example 1, PTFE dispersion (31-JR manufactured by Mitsui Chemours Fluoro Products Co., Ltd.) was applied to carbon paper TGP-H-060 (manufactured by Toray Industries, Inc., 200 um thick) as the oxygen channel and positive electrode current collector. A lithium-air secondary battery was produced and charged in the same manner as in Example 1, except that it was impregnated to 30% after drying and treated at 360 ° C. for 30 minutes in an air atmosphere. Discharge cycle characteristics and the like were measured. Table 1 shows the results.
As shown in Table 1, in Example 2, the porosity and electrolyte repellency of the oxygen channel material were 74.2% and 0.95, respectively. , 15 times.

[Example 3]
In Example 1, FEP dispersion (120-JRB manufactured by Mitsui Chemours Fluoro Products Co., Ltd.) was applied to carbon paper TGP-H-060 (manufactured by Toray Industries, Inc., 200 um thick) as the oxygen channel and positive electrode current collector. A lithium-air secondary battery was produced and charged in the same manner as in Example 1, except that it was impregnated to 10% after drying and treated at 340 ° C. for 30 minutes in an air atmosphere. Discharge cycle characteristics and the like were measured. Table 1 shows the results.
As shown in Table 1, in Example 3, the porosity and electrolyte repellency of the oxygen channel material were 80.0% and 0.95, respectively. , 16 times.

[Comparative Example 2]
In Example 2, carbon paper TGP-H-060 (manufactured by Toray Industries, Inc., 200 μm thick), which was not subjected to electrorepellent treatment and was not subjected to PTFE coating treatment, was used as the oxygen channel and positive electrode current collector. A lithium-air secondary battery was produced in the same manner as in Example 2, and the charge-discharge cycle characteristics and the like were measured. Table 1 shows the results.
As shown in Table 1, in Comparative Example 2, the porosity and electrolyte repellency of the oxygen channel material were 80.7% and 0.48, respectively. , six times.

As is clear from Table 1, in Comparative Examples 1 and 2 in which the oxygen channels were not subjected to the electro-repellent treatment, the porosity of the oxygen channel material was relatively high at 80.7% to 89.5%. It was observed that the electrolyte repellency of the oxygen channel material was as low as 0.48 to 0.58, and as a result, the charge/discharge cycle characteristics were as low as 2 to 6 cycles.
On the other hand, unlike Comparative Examples 1 and 2, in Examples 1 to 3 using the oxygen channels subjected to the electrorepellent treatment, the porosity of the oxygen channel material was 74.2% to 88.4%. The relatively high degree of electrolyte repellency of the oxygen channel material is 0.95 to 0.96, and as a result, the charge/discharge cycle characteristics are as high as 12 to 16 times, a clear difference from the comparative example. was observed in
From Table 1, even if the oxygen channel material has a relatively high porosity of 74.2% to 88.4%, it is possible to relatively increase the liquid repellency of the oxygen channel material by performing the electrorepellent treatment. , it was shown that the charge-discharge cycle characteristics were clearly improved.

According to the present invention, even lithium-air batteries with a limited amount of electrolyte due to high energy density design can be expected to have improved cycle characteristics. It is possible to further improve the ability to have. Therefore, the present invention can be applied to lithium-air batteries that are compact, lightweight, and suitable for increasing capacity.

100, 200 lithium air battery (lithium air secondary battery)
101 Positive electrode, positive electrode structure 102 Positive electrode layer 103 Oxygen channel/positive current collector 104 Negative electrode, negative electrode structure 105 Negative electrode active material layer 106 Negative electrode current collector 107 Non-aqueous electrolyte layer 108 Solid electrolyte (layer)
109 Separator 110 Glass plate 111 Stainless steel plate 112 Fixing screw 113 Fixing washer 114 Post 115 Spring 116 Spacer 300 Laminated lithium-air battery

Claims (5)

A lithium-air battery comprising a negative electrode, a separator filled with a non-aqueous electrolyte, and a positive electrode,
The negative electrode includes a negative electrode active material layer containing lithium and a negative electrode current collector,
The positive electrode includes a positive electrode layer having a porous structure and an oxygen channel for taking in oxygen as a positive electrode active material,
A lithium-air battery using an oxygen channel material that satisfies the following conditions as the oxygen channel:
(1) the oxygen channel material has a porosity of 60% or more;
(2) The oxygen channel material has the following formula:
Degree of electrolyte repellency = 1 - [amount of non-aqueous electrolyte absorbed by oxygen channel material/amount of voids in oxygen channel material]
(However, the amount of the non-aqueous electrolyte absorbed by the oxygen channel material is the weight obtained by drying and weighing only the oxygen channel cut to a size of 15 × 15 mm in advance before configuring the air battery, and the weight of the oxygen channel. The oxygen channel was immersed in the non-aqueous electrolytic solution for 1 minute and then weighed. based on volume)
is 0.80 or more and 0.98 or less. 2. The lithium-air battery of claim 1, wherein the oxygen channel also functions as a positive current collector, or the positive electrode further comprises a positive current collector. 3. The positive electrode according to claim 1, wherein the positive electrode layer is laminated on both sides of the oxygen channel, and the negative electrode is formed by laminating the negative electrode active material layer on both sides of the negative electrode current collector. of lithium-air batteries. The oxygen channel according to any one of claims 1-3. The oxygen channel according to any one of claims 1 to 4, wherein the surface is coated with an organic compound having electrolyte repellency.

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