JP2017091601A - Lithium air secondary battery and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lithium air secondary battery capable of enhancing the charge/discharge cycle performance and energy efficiency thereof while increasing the discharge capacity.SOLUTION: A gas diffusion type air electrode 101 as the cathode is constituted of: a carrier made of a porous body 111; and a carbon co-continuous porous body 112 of a carbon of the three-dimensional network structure which is continuously carried over the entire area of the carrier 111. The carbon co-continuous porous body 112 has an integral structure. The lithium air secondary battery includes a catalyst 113 carried by the air electrode 101. The catalyst 113 is adhered on the surfaces of the carrier 111 and a carbon co-continuous porous body 112.SELECTED DRAWING: Figure 1B

Description

  The present invention relates to a lithium-air secondary battery using oxygen as a positive electrode active material and a method for manufacturing the same.

  A lithium-air secondary battery that uses oxygen in the air as a positive electrode active material is always supplied with oxygen from the outside of the battery, and a large amount of metallic lithium, which is a negative electrode active material, can be filled in the battery. For this reason, it has been reported that the value of the discharge capacity per unit weight of the battery can be greatly increased.

  Up to now, as reported in Non-Patent Document 1, attempts have been made to improve battery performance such as discharge capacity and cycle characteristics by adding various catalysts to the gas diffusion air electrode as the positive electrode. Yes.

  In Non-Patent Document 1, as for an air electrode composed mainly of carbon powder, a carbon simple substance not supporting a catalyst and a system in which nine types of catalysts are supported on a carbon simple substance are studied, and the carbon contained in the air electrode is examined. A very large discharge capacity of 1000 to 3000 mAh / g is obtained per weight.

However, it has been found that in a lithium-air secondary battery using a powder raw material for the air electrode, a significant decrease in discharge capacity occurs when charging and discharging are repeated. This is presumably because the internal resistance of the air electrode increases due to the occurrence of many portions where the internal conductive paths are cut. For example, when the air electrode is composed mainly of a single carbon powder, the capacity retention rate is about 10% in two charge / discharge cycles, and a significant decrease in capacity is observed. For example, even when Co ₃ O ₄ is supported on a single carbon as a catalyst to form an air electrode, the capacity retention rate becomes about 65% in 10 cycles and the discharge capacity decreases.

  As described above, in a lithium air secondary battery using a powder raw material for the air electrode, a significant reduction in capacity is observed, and sufficient characteristics as a secondary battery are not obtained. Moreover, in the lithium air secondary battery in the technology of Non-Patent Document 1, in many cases, the average discharge voltage is about 2.5 V, while the charging voltage is 4.0 to 4.5 V, even the lowest one. It is about 3.9V. For this reason, the lithium-air secondary battery of Non-Patent Document 1 has low charge / discharge energy efficiency.

  In contrast to the above-described technique, a technique has been proposed in which an air electrode is configured using a porous metal body without using a powder such as carbon as a raw material for the air electrode (see Non-Patent Document 2). In the lithium-air secondary battery according to this technology, an air electrode is formed by using a metal porous body made of gold (Au), and a very excellent cycle performance with a capacity retention rate of 95% or more after 100 cycles of charge and discharge is obtained. Yes. Moreover, the average discharge voltage of this lithium air secondary battery is about 2.6V, and a charging voltage is about 3.5V. As described above, in the technique of Non-Patent Document 2, a high energy efficiency is obtained with a small voltage difference with respect to charging and discharging.

A. Debart et al., "An O2 cathode for rechargeable lithium batteries: The effect of a catalyst", Journal of Power Sources, vol.174, pp.1177-1182, 2007. Z. Peng et al., "A Reversible and Higher-Rate Li-O2 Battery", Science, vol.337, pp.563-566, 2012.

  However, in the technique of Non-Patent Document 2, since a metal is used for the air electrode, the weight density of the air electrode is high and the discharge capacity is only about 300 mAh / g. Further, since expensive Au is used for the air electrode, the battery cost is also a problem. Thus, conventionally, there has been a problem that it is not easy to increase the discharge capacity while increasing the charge / discharge cycle performance and energy efficiency of the lithium-air secondary battery.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to improve the charge / discharge cycle performance and energy efficiency of a lithium-air secondary battery and to increase the discharge capacity.

  A lithium-air secondary battery according to the present invention includes a carrier composed of a porous body, an air electrode composed of a carbon co-continuous porous body composed of carbon having a three-dimensional network structure continuously supported over the entire area of the support, and lithium. And an electrolyte disposed between the air electrode and the negative electrode.

  The lithium air secondary battery may include a catalyst carried on the air electrode. Catalyst is titanium oxide, vanadium oxide, chromium oxide, manganese oxide, iron oxide, cobalt oxide, nickel oxide, copper oxide, zinc oxide, molybdenum oxide, silver oxide, cadmium oxide Made of at least one metal oxide of palladium oxide, lead oxide, ruthenium oxide, rhodium oxide, praseodymium oxide, cerium oxide, niobium oxide, yttrium oxide, tantalum oxide, and tin oxide It only has to be done. Further, the metal oxide may be a hydrate containing water molecules.

  The lithium air secondary battery may include a catalyst carried on the air electrode. The catalyst is at least one of titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, molybdenum, silver, cadmium, palladium, lead, ruthenium, rhodium, praseodymium, cerium, niobium, yttrium, tantalum, and tin. It may be composed of two metals.

  The method for producing a lithium-air secondary battery according to the present invention includes a first step of obtaining a high molecular weight solution by dissolving polyacrylonitrile in a good solvent for polyacrylonitrile, and a high molecular weight solution on a porous carrier. A second step of coating, and a carrier coated with a high molecular weight solution is exposed to a poor solvent for polyacrylonitrile, thereby precipitating a polymer co-continuous porous body having a three-dimensional network structure continuously supported over the entire region of the carrier. 3 steps and heat treatment of the polymer co-continuous porous material supported on the carrier to form a carbon co-continuous porous material having a three-dimensional network structure, so that the three-dimensional network carbon co-supported continuously supported over the entire area of the carrier. 4th process which produces the air electrode which consists of a continuous porous body, the air electrode, the negative electrode comprised including lithium, and the electrolyte arrange | positioned between the air electrode and the negative electrode And a fifth step of making a by lithium air secondary battery composed.

  In the method for producing a lithium-air secondary battery, the fourth step is to immerse the support on which the carbon co-continuous porous body is supported in an aqueous solution of a surfactant to place the surfactant on the surface of the carbon co-continuous porous body and the support. A sixth step of attaching, a seventh step of attaching a metal salt by a surfactant to the surface of the carbon co-continuous porous material and the carrier to which the surfactant is attached using an aqueous solution of the metal salt, and a carbon to which the metal salt is attached You may make it provide the 8th process of carrying | supporting the catalyst which consists of the metal or metal oxide which comprises a metal salt on a carbon co-continuous porous body and a support | carrier by heat processing with respect to a co-continuous porous body and a support | carrier.

  In the method for producing a lithium-air secondary battery, the fourth step is a sixth step in which the metal co-continuous porous body and the carrier are immersed in an aqueous solution of a metal salt to attach the metal salt to the surfaces of the carbon co-continuous porous body and the carrier. And a seventh step of supporting the catalyst comprising the metal constituting the metal salt on the carbon co-continuous porous material and the carrier by heat treatment on the carbon co-continuous porous material and the carrier on which the metal salt is adhered, and the carbon co-supporting carbon on which the catalyst is supported. You may make it provide the 8th process which makes a catalyst a metal oxide hydrate by making a continuous porous body and a support | carrier act on high temperature / high pressure water.

  In the method for producing a lithium-air secondary battery, the fourth step is a sixth step in which the metal co-continuous porous body and the carrier are immersed in an aqueous solution of a metal salt to attach the metal salt to the surfaces of the carbon co-continuous porous body and the carrier. And a catalyst comprising a metal oxide hydrate of a metal constituting the metal salt by allowing the carbon co-continuous porous body and the carrier to which the metal salt is adhered to to act on high-temperature and high-pressure water. You may make it provide the 7th process made to carry.

  In any of the production methods, the metal is titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, molybdenum, silver, cadmium, palladium, lead, ruthenium, rhodium, praseodymium, cerium, niobium, yttrium, At least one of tantalum and tin may be used.

  As described above, according to the present invention, the air electrode is composed of a porous carrier and a carbon co-continuous porous body having a three-dimensional network structure continuously supported over the entire area of the carrier. As a result, the charge / discharge cycle performance and energy efficiency can be increased, and the discharge capacity can be increased.

FIG. 1A is a configuration diagram showing a configuration of a lithium-air secondary battery in an embodiment of the present invention. FIG. 1B is a configuration diagram showing a partial configuration of the lithium-air secondary battery according to the embodiment of the present invention. FIG. 2 is a cross-sectional view showing a more detailed configuration example of the lithium air secondary battery. FIG. 3 is a characteristic diagram showing states of initial discharge (solid line) and charge (broken line) of the lithium-air secondary battery in Example 1. FIG. 4 is a characteristic diagram showing the cycle dependency of the discharge capacity in Examples 1 to 5 and Comparative Examples 1 and 2.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1A and 1B are configuration diagrams showing a configuration of a lithium air secondary battery according to an embodiment of the present invention. FIG. 1B shows an enlarged part of the air electrode 101 of FIG. 1A.

  This lithium-air secondary battery is a positive electrode gas diffusion type air electrode 101, a negative electrode 102 containing lithium, and an air electrode 101, similarly to a general well-known lithium-air secondary battery. And an electrolyte 103 disposed between the anode 102 and the anode 102. One surface of the air electrode 101 is exposed to the atmosphere, and the other surface is in contact with the electrolyte 103. Further, the surface of the negative electrode 102 on the side of the electrolyte 103 is in contact with the electrolyte 103. The electrolyte 103 may be either an electrolytic solution or a solid electrolyte. The electrolytic solution refers to a case where the electrolyte is in a liquid form. Moreover, a solid electrolyte means the case where electrolyte is a gel form or a solid form.

  In addition to the basic configuration described above, in the embodiment of the present invention, as shown in FIG. 1B, the air electrode 101 is a porous carrier 111 and a carbon having a three-dimensional network structure continuously supported over the entire region of the carrier 111. It is comprised from the carbon co-continuous porous body 112 by. The carbon co-continuous porous body 112 has an integral structure. In the example shown in FIG. 1B, a catalyst 113 supported on the air electrode 101 is provided. The catalyst 113 is attached to the surfaces of the carrier 111 and the carbon co-continuous porous body 112.

  In the air electrode 101, an electrode reaction proceeds in a three-phase portion (three-phase interface site) of electrolyte / electrode (carbon) / air (oxygen). In order to increase the efficiency of the battery, it is desirable that there are more three-phase interface sites that cause an electrode reaction. From such a viewpoint, it is considered that the specific surface area of the carbon co-continuous porous body 112 should be as large as possible.

The carbon co-continuous porous body 112 can be prepared by a known process such as sintering of carbon powder. However, as described above, the lithium-air secondary battery generates a large amount of the three-phase interface sites of the air electrode 101 on the electrode surface. The carbon co-continuous porous body 112 constituting the air electrode 101 to be used preferably has a high specific surface area. For example, the specific surface area of the carbon co-continuous porous body 112 is preferably 30 m ² / g or more, and more preferably 100 m ² / g or more.

  When the carbon co-continuous porous body 112 is prepared (manufactured) by the sintering method, the sintering temperature of carbon is as high as about 1600 ° C., and in this method, the grain growth between the carbon powders proceeds rapidly. The carbon co-continuous porous body 112 is difficult to produce.

  On the other hand, first, a carrier 111 carrying a polymer co-continuous porous body is prepared in advance, and the carrier 111 carrying a carbon co-continuous porous body 112 obtained by heat treatment in an inert atmosphere has a high ratio. A carbon co-continuous porous body 112 having a surface area can be obtained. For example, the carbon co-continuous porous body 112 can be produced from polyacrylonitrile by the production method described later.

  For example, the carrier 111 preferably has an average pore diameter of 0.1 to 3 μm, and more preferably 0.1 to 2 μm. Here, the average pore diameter is a value obtained by a mercury intrusion method.

  The air electrode 101 does not need to use an additional material such as a binder as in the case of using carbon powder, and is advantageous in terms of cost.

  In the lithium-air secondary battery of the present invention, a transition metal catalyst or transition metal oxide catalyst having high activity for both oxygen reduction (discharge) and oxygen generation (charge) reactions is added to the air electrode 101 as the catalyst 113. Thus, it can function as a secondary battery with higher performance.

  The transition metal or transition metal oxide is not particularly limited as long as it can be used as the catalyst 113 and can be attached to the carbon co-continuous porous body 112.

  For example, the catalyst 113 is titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn). , Molybdenum (Mo), silver (Ag), cadmium (Cd), palladium (Pd), lead (Pb), ruthenium (Ru), rhodium (Rh), praseodymium (Pr), cerium (Ce), niobium (Nb) , Yttrium (Y), tantalum (Ta), and tin (Sn). In particular, Ru is preferable.

For example, the catalyst 113 may be composed of the above-described metal oxide. In particular, ruthenium oxide (RuO ₂ ) is suitable. RuO ₂ is preferable because it shows particularly excellent catalytic performance.

The metal oxide used as the catalyst 113 is also preferably an amorphous hydrate. For example, the transition metal oxide hydrate described above may be used. More specifically, it may be ruthenium (IV) oxide hydrate [RuO ₂ · nH ₂ O]. Note that n is the number of moles of H ₂ O with respect to 1 mol of RuO ₂ .

For example, the air electrode 101 is obtained by attaching (adding) ruthenium oxide hydrate (RuO ₂ .nH ₂ O) as nano-sized fine particles on the carbon co-continuous porous body 112 of the air electrode 101 with high dispersion. By using it, it becomes possible to show the outstanding battery performance. The content of the catalyst 113 contained in the air electrode 101 is 0.1 to 70% by weight, preferably 1 to 30% by weight, based on the total weight of the air electrode 101.

  By adding a transition metal oxide as the catalyst 113 to the air electrode 101, battery performance is greatly improved. The electrolyte solution of the electrolyte 103 penetrates into the air electrode 101, and oxygen gas in the atmosphere is supplied at the same time, and the above-described three-phase interface of electrolyte solution-electrode-gas (oxygen) is formed. If the catalyst 113 is highly active at this three-phase interface site, oxygen reduction (discharge) and oxygen generation (charge) on the electrode surface proceed smoothly, and battery performance is greatly improved.

  The electrode reaction on the air electrode 101 can be expressed as follows.

2Li ⁺ + (1/2) O ₂ + 2e ⁻ → Li ₂ O (1)
2Li ⁺ + O ₂ + 2e ⁻ → Li ₂ O ₂ (2)

Lithium ions (Li ⁺ ) in the above formula are dissolved in the electrolyte 103 by electrochemical oxidation from the negative electrode 102 and have moved through the organic electrolyte to the surface of the air electrode 101. Oxygen (O ₂ ) is taken into the air electrode 101 from the atmosphere (air). Note that the material (Li ⁺ ) dissolved from the negative electrode 102, the material (Li ₂ O ₂ ) deposited at the air electrode 101, and air (O ₂ ) are shown together with the components shown in FIG.

The metal oxide that can be used as the catalyst 113 of the air electrode 101 can take various oxidation states. For example, ruthenium oxide (RuO ₂ ) or the like can be present in an ion in which ruthenium has a valence of +4, +3, or the like. Further, depending on conditions in the synthesis of these oxides, there may be a vacancy (also referred to as an oxygen vacancy in this specification) that can incorporate oxygen into an oxide such as ruthenium oxide.

  Since such a catalyst 113 has a strong interaction with oxygen as the positive electrode active material, it can adsorb many oxygen species on its surface or occlude oxygen species in oxygen vacancies.

  As described above, the oxygen species adsorbed on the surface of the metal oxide constituting the catalyst 113 or occluded in the oxygen vacancy is an oxygen source (active intermediate reaction) of the above formulas (1) and (2). Used in the oxygen reduction reaction, and the above reaction proceeds easily. Moreover, said metal oxide has activity also with respect to the charging reaction which is a reverse reaction of Formula (1) and Formula (2). Therefore, the oxygen generation reaction on the air electrode 101 corresponding to the charging of the battery also proceeds efficiently. Thus, a metal oxide such as ruthenium oxide functions effectively as the catalyst 113. In addition to such a metal oxide, the metal itself can be used as the catalyst 113, and the metal functions in the same manner as the metal oxide.

In the lithium air secondary battery, as described above, in order to increase the efficiency of the battery, it is desirable that there are more reaction sites (the above-described three-phase portion of electrolyte / electrode / air (oxygen)) that cause an electrode reaction. . From such a viewpoint, it is important that the above-mentioned three-phase sites are also present in a large amount on the surface of the catalyst 113, and the catalyst 113 preferably has a high specific surface area. The specific surface area of the catalyst 113 with a metal or metal oxide, 0.1~1000m ² / g, preferably may be a 1 to 500 ² / g. The specific surface area is the specific surface area determined by the BET method by known N ₂ adsorption.

  The air electrode 101 to which the catalyst 113 is added can be manufactured by a method for manufacturing the air electrode 101 of the lithium air secondary battery described later.

Next, the negative electrode 102 will be described. The negative electrode 102 is composed of a negative electrode active material. The negative electrode active material is not particularly limited as long as it is a material that can be used as a negative electrode material for a lithium-air secondary battery. For example, metallic lithium can be mentioned. Alternatively, examples include lithium and an alloy of silicon and tin, or lithium nitride such as Li _2.6 Co _0.4 N, which is a substance capable of inserting and extracting lithium ions.

  Note that in the case where a silicon or tin alloy is used as the negative electrode 102, silicon or tin which does not contain lithium can be used when the negative electrode 102 is formed. However, in this case, prior to the production of the lithium-air secondary battery, a chemical method or an electrochemical method (for example, a method in which an electrochemical cell is assembled and lithium and silicon or tin are alloyed) is used. It is necessary to treat the silicon or tin so that it is in a state containing lithium.

  Specifically, it is preferable to perform electrochemical treatment such as alloying by using silicon or tin as the working electrode, lithium as the counter electrode, and flowing a reducing current in the organic electrolyte.

  The reaction at the time of discharge in the negative electrode 102 composed of metallic lithium can be expressed as follows.

Li → Li ⁺ + e ⁻ (3)

  On the other hand, in the negative electrode 102 at the time of charging, a lithium precipitation reaction which is the reverse reaction of the formula (3) occurs.

  The negative electrode 102 can be formed by a known method. For example, in the case where lithium metal is used as the negative electrode 102, the negative electrode 102 may be manufactured by stacking a plurality of metal lithium foils into a predetermined shape.

Next, the electrolyte 103 will be described. The electrolyte 103 may be any substance that can move lithium ions between the air electrode 101 (positive electrode) and the negative electrode 102. For example, the electrolyte 103 may be a nonaqueous solvent (organic solvent) in which a metal salt containing lithium ions is dissolved. Specifically, examples of the metal salt containing lithium ions include metals containing lithium ions such as lithium bistrifluoromethanesulfonylimide (LiTFSI), lithium perchlorate (LiClO ₄ ), and lithium hexafluorophosphate (LiPF ₆ ). Mention may be made of salts.

  Nonaqueous solvents include dimethyl carbonate (DMC), methyl ethyl carbonate (MEC), methyl propyl carbonate (MPC), methyl isopropyl carbonate (MIPC), methyl butyl carbonate (MBC), diethyl carbonate (DEC), and ethyl propyl carbonate. (EPC), ethyl isopropyl carbonate (EIPC), ethyl butyl carbonate (EBC), dipropyl carbonate (DPC), diisopropyl carbonate (DIPC), dibutyl carbonate (DBC), ethylene carbonate (EC), propylene carbonate (PC), carbonic acid 1, Carbonate ester solvents such as 2-butylene (1,2-BC), ether solvents such as 1,2-dimethoxyethane (DME) and tetraethylene glycol dimethyl ether (TEGDME), and lactone systems such as γ-butyrotactone (GBL) Solvent, or dimethylsulfoxy (DMSO) can be mentioned sulfoxide solvents solvent or a mixture of two or more from these, such as. Examples of the solvent in which two or more kinds are mixed include a mixed solvent of ethylene carbonate (EC) and dimethyl carbonate (DMC) (volume ratio 1: 1), a mixed solvent such as EC and diethyl carbonate (DEC). it can.

Other materials constituting the electrolyte 103 include a solid electrolyte that passes lithium ions (eg, a sulfide-based solid electrolyte containing Li ₂ S and P ₂ S ₅ ), and a polymer electrolyte that passes lithium ions (eg, polyethylene oxide). System, specifically, for example, a material obtained by compositing the organic electrolyte and polyethylene oxide). However, the material constituting the electrolyte 103 is not limited to these, and can be suitably used as long as it is a known solid electrolyte that passes lithium ions or a polymer electrolyte that passes lithium ions used in lithium-air secondary batteries. .

  In addition to the above configuration, the lithium-air secondary battery can include structural members such as a separator, a battery case, and a metal mesh (for example, titanium mesh), and elements required for the lithium-air secondary battery. Conventionally known ones can be used.

  Next, a manufacturing method will be described. The lithium air secondary battery of the present invention includes an air electrode, a negative electrode, and an electrolyte obtained by an air electrode manufacturing method, which will be described later, together with other necessary elements based on the structure of a desired lithium air secondary battery. It can be produced by appropriately arranging in an appropriate container. A conventionally known method can be applied to the manufacturing procedure of these lithium air secondary batteries.

  Hereinafter, production of the air electrode 101 will be described.

[Production Method 1]
First, the manufacturing method 1 will be described.

  First, polyacrylonitrile is dissolved in a good solvent for polyacrylonitrile to prepare a high molecular weight solution (first step).

  Next, the high molecular weight solution is applied to the porous carrier 111 (second step).

  Next, by exposing the carrier 111 coated with the high molecular weight solution to a poor solvent for polyacrylonitrile, a polymer co-continuous porous body having a three-dimensional network structure continuously supported over the entire region of the carrier 111 is deposited (first). 3 steps).

  Next, the air electrode 101 composed of the carbon co-continuous porous body 112 having a three-dimensional network structure is obtained by heat-treating the polymer co-continuous porous body supported on the carrier 111 (fourth step).

  Thereafter, the lithium-air secondary composed of the air electrode 101 manufactured as described above, the negative electrode 102 including lithium, and the electrolyte 103 disposed between the air electrode 101 and the negative electrode 102. A battery is manufactured (fifth step).

  Hereinafter, each step will be described in more detail.

  In the first step, a solution of a high molecular weight material as a raw material of the carbon co-continuous porous body 112 having a three-dimensional network structure may be prepared, and this high molecular weight material need not be all polyacrylonitrile. The high molecular weight material may be a polymer containing 85% by weight or more, more preferably 90% by weight or more of polyacrylonitrile, and the high molecular weight material contains components such as methyl acrylate and vinyl acetate other than polyacrylonitrile. May be. Thus, when using the high molecular weight body which also contains components other than polyacrylonitrile, what is necessary is just to use the good solvent of a high molecular weight body at a 1st process. The molecular weight of polyacrylonitrile is not limited, but the average molecular weight is preferably, for example, 10,000 to 5,000,000, and more preferably 20,000 to 4,000,000.

  Here, the good solvent indicates a solvent having the ability to dissolve the target high molecular weight substance (the high molecular weight body has high solubility). Specifically, it means a solvent in which 10 g or more, more preferably 15 g or more of polyacrylonitrile is dissolved in 1 liter (L) of a good solvent. Good solvents for polyacrylonitrile are, for example, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), dimethylacetamide (DMA), N-methylpyrrolidone (NMP), and the like. Also good.

  In the first step, polyacrylonitrile is added to the good solvent and dissolved in the solvent using a necessary method such as stirring while heating as necessary. The high molecular weight solution produced in the first step has a polyacrylonitrile concentration of 5 to 300 g / L, preferably 10 to 160 g / L.

  In the second step, the high molecular weight solution prepared in the first step is applied to the carrier 111, and a precursor of a polymer co-continuous porous body having a three-dimensional network structure is supported on the carrier 111. Here, the support | carrier 111 is comprised from the material which has the capability to adhere the said high molecular weight solution. Specifically, the carrier 111 is composed of a material to which the high molecular weight solution adheres in an amount of 0.001 g or more, more preferably 0.05 g or more with respect to 1 g of the carrier 111.

The carrier 111 can be used in the form of a sheet, foam, mesh, honeycomb, fiber, nonwoven fabric, woven fabric, or the like. Furthermore, the carrier 111 preferably has electrical conductivity, specifically, 10 S / m or more, more preferably 10 ² S / m or more. As the carrier 111, for example, a carbon sheet, a porous metal, a metal mesh, a metal sheet, or the like can be used, and a carbon sheet that is strong in corrosion resistance and light in weight is particularly preferable.

  In the third step, a poor solvent for the polyacrylonitrile polymer) is sprayed on the polymer solution to precipitate a polymer co-continuous porous body having a three-dimensional network structure on the carrier 111. Here, the poor solvent means a solvent having a small ability (solubility is low) to dissolve the target high molecular weight substance.

  Specifically, a solvent that does not dissolve 1 g or more, more preferably 0.8 g or more, of the high molecular weight body with respect to 1 L of the solvent is a poor solvent. The poor solvent used here is, for example, water, acetonitrile, ethylene glycol, methanol, ethanol, isopropanol, ethylene glycol, glycerin, or the like, and may be a solvent in which two or more of these are mixed.

  The third step is performed, for example, by exposing the carrier 111 coated with the high molecular weight solution obtained in the second step to the poor solvent. Specifically, it may be washed with a poor solvent 10 times or more, more preferably 100 times or more of the high molecular weight solution. The washing may be carried out until the polymer co-continuous porous material is all precipitated from the good solvent and further the good solvent diffuses from the polymer co-continuous porous material into the poor solvent.

  The method of exposing the poor solvent to the high molecular weight solution with the good solvent is not particularly limited, but there are a method in which the poor solvent is pressurized and sprayed, a method of pouring the poor solvent, a method of immersing in the poor solvent, etc. . It is possible to freely control the pore size, porosity, specific surface area, etc. of the high molecular weight co-continuous porous material to be precipitated by controlling the time for the poor solvent to diffuse into the high molecular weight solution with the good solvent. . The faster the diffusion speed, the higher the specific surface area becomes possible, and it is preferable to expose a large amount of poor solvent to the high molecular weight solution with a good solvent in a short time. For example, when washing with running water, the washing may be done with running water of 1 L or more per minute for 1 g of the high molecular weight solution.

  In a conventionally known method for producing a polymer co-continuous porous body, first, a polymer such as polyacrylonitrile is added to a mixed solvent of a poor solvent and a good solvent, and this solution is heated to dissolve the polymer. The resulting solution was then cooled to precipitate a polymer co-continuous porous body.

  In such a conventional manufacturing method, a step of heating the solution at a relatively high temperature is required to dissolve the polymer, and the solvent is volatilized, and it is not easy to control the concentration of the polymer solution to be constant. . For this reason, the pore diameter, porosity, specific surface area, etc. of the co-continuous porous material to be deposited cannot be freely controlled.

  On the other hand, the production method of the present invention does not require heating at a high temperature, can not only freely control the characteristics such as the pore diameter of the polymer co-continuous porous material to be deposited, but also facilitates the production process.

  By the way, it is possible to deposit only the high molecular weight co-continuous porous material without using the carrier 111. For example, by taking the good solvent solution of the high molecular weight substance obtained in the first step in a suitable container such as a petri dish, and spraying the poor solvent on the solution in the container, only the high molecular weight body continuous porous body is obtained. It can be deposited. However, when the carrier 111 is not used, in order to obtain a flat high molecular weight co-continuous porous material, it is necessary to deposit the high molecular weight co-continuous porous material uniformly and gradually using a spray or the like. For this reason, there is a limit to the speed at which the poor solvent is diffused into the high molecular weight solution, and there is a limit to increasing the specific surface area as compared with the case where the carrier 111 is not used.

  Even if the carrier 111 is not used, the carbon co-continuous porous body 112 can be produced by performing the fourth step. However, the carbon co-continuous porous body 112 has a problem that it is brittle because it is highly brittle. For this reason, the carbon co-continuous porous body alone breaks easily when pressure is applied. In the present invention, the problem of brittleness of the carbon co-continuous porous body 112 is solved by using the carrier 111 having high mechanical strength.

  In the fourth step, the carrier 111 carrying the polymer co-continuous porous body is baked at 800 ° C. to 1500 ° C., more preferably 900 ° C. to 1400 ° C. in an inert or reducing atmosphere, and carbonized. .

  Here, the gas used in the inert or reducing atmosphere is not particularly limited as long as the polymer co-continuous porous body does not burn, but for example, nitrogen gas, argon gas, hydrogen gas, carbon dioxide gas, monoxide Examples thereof include carbon gas. For example, carbon dioxide gas or carbon monoxide gas that has an activation effect on the carbon material and can be expected to increase the specific surface area of the carbon co-continuous porous body 112 is more preferable.

  The carbon co-continuous porous body 112 can also be prepared by using a known method such as sintering carbon powder, but in such a method, the sintering temperature of carbon is as high as about 1600 ° C. For this reason, in the sintering method, the grain growth between the carbon powders proceeds rapidly, and it becomes difficult to produce the carbon co-continuous porous body 112 having a high specific surface area. For this reason, as described above, the polymer co-continuous porous body is first prepared, and then the carbon co-continuous porous body is heat-treated in an inert or reducing atmosphere to prepare the carbon co-continuous porous body 112. Is preferred.

[Production Method 2]
Next, manufacturing method 2 will be described.

  As described above, the air electrode 101 may further include a catalyst 113 made of a transition metal or a transition metal oxide. In manufacturing method 2, as described in manufacturing method 1, after preparing carrier 111 on which carbon co-continuous porous body 112 is supported, catalyst 113 is further supported on carrier 111 on which carbon co-continuous porous body 112 is supported. .

  In the manufacturing method 2, the following 6th process, 7th process, and 8th process are added in the 4th process mentioned above.

  In the sixth step, the carrier 111 on which the carbon co-continuous porous body 112 is supported is immersed in an aqueous solution of a surfactant, and the surfactant is attached to the surfaces of the carbon co-continuous porous body 112 and the carrier 111.

  Next, in the seventh step, the metal salt is attached to the surfaces of the carbon co-continuous porous body 112 and the carrier 111 to which the surfactant is attached using an aqueous solution of the metal salt.

  Next, in the eighth step, the carbon co-continuous porous body 112 and the carrier 111 are made of the metal or metal oxide constituting the metal salt by heat treatment on the carbon co-continuous porous body 112 and the carrier 111 to which the metal salt is attached. 111.

  The above metals are titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, molybdenum, silver, cadmium, palladium, lead, ruthenium, rhodium, praseodymium, cerium, niobium, yttrium, tantalum, and tin. It is sufficient if it is at least one of the following. In particular, ruthenium is preferable.

By the way, in order to carry the transition metal oxide on the carbon co-continuous porous body 112, a conventionally known method can be used. For example, the carrier 111 on which the carbon co-continuous porous body 112 is supported is impregnated with an aqueous solution of transition metal chloride or transition metal nitrate, evaporated to dryness, and then hydrothermally heated in high-temperature and high-pressure water (H ₂ O). There is a way to synthesize. Further, there is a precipitation method in which a carrier 111 on which a carbon co-continuous porous body 112 is supported is impregnated with an aqueous solution of transition metal chloride or transition metal nitrate, and an alkaline aqueous solution is dropped here. Further, there is a sol-gel method in which a transition metal alkoxide solution is impregnated on a carrier 111 on which a carbon co-continuous porous body 112 is supported, and this is hydrolyzed. The conditions of each method by these liquid phase methods are well-known, and these well-known conditions can be applied. In the present invention, the liquid phase method is desirable.

  In many cases, the metal oxide supported by the liquid phase method is in an amorphous state because crystallization has not progressed. A crystalline metal oxide can be obtained by heat-treating the precursor in an amorphous state at a high temperature of about 500 ° C. in an inert atmosphere. Such a crystalline metal oxide exhibits high performance even when used as the catalyst 113 of the air electrode 101.

On the other hand, the precursor powder obtained when the above amorphous precursor is dried at a relatively low temperature of about 100 to 200 ° C. is in a hydrated state while maintaining an amorphous state. The metal oxide hydrate is formally Me _x O _y · nH ₂ O (where Me means the above metal, x and y are the number of metals and oxygen contained in the metal oxide molecule, respectively). Where n is the number of moles of H ₂ O per mole of metal oxide). A metal oxide hydrate obtained by such low-temperature drying can be used as the catalyst 113.

  Since the amorphous metal oxide (hydrate) is hardly sintered, it has a large surface area and a very small particle diameter of about 30 nm. This is suitable as the catalyst 113, and by using this, excellent battery performance can be obtained.

  As described above, crystalline metal oxides show high activity, but metal oxides crystallized by heat treatment at a high temperature as described above may have a significant decrease in surface area. May be about 100 nm. The particle diameter (average particle diameter) is a value obtained by observing with a scanning electron microscope (SEM) or the like, measuring the diameter of particles per 10 μm square (10 μm × 10 μm), and calculating the average value. .

  In particular, the metal oxide catalyst 113 that has been heat-treated at a high temperature aggregates particles, and therefore it may be difficult to add the catalyst 113 to the surface of the carbon co-continuous porous body 112 with high dispersion. In order to obtain a sufficient catalytic effect, a large amount of metal oxide may have to be added to the air electrode 101, and catalyst preparation by high-temperature heat treatment may be disadvantageous in cost.

  In order to solve this problem, in the production method 2, as shown in the above-described sixth to eighth steps, a surfactant is used.

  The surfactant used in the sixth step of the production method 2 is for supporting a metal or a transition metal oxide on the air electrode 101 with high dispersion. As long as it has a hydrophobic group that adsorbs to the carbon surface and a hydrophilic group that adsorbs transition metal ions in the molecule, such as a surfactant, metal ions that are transition metal oxide precursors in the carbon co-continuous porous body 112 Can be adsorbed with a high degree of dispersion.

  The surfactant described above is not particularly limited as long as it has a hydrophobic group that adsorbs to the carbon surface and a hydrophilic group that adsorbs ruthenium ions in the molecule, but a nonionic surfactant is preferable. Examples of the ester type surfactant include glyceryl laurate, glyceryl monostearate, sorbitan fatty acid ester, and sucrose fatty acid ester. Examples of ether type surfactants include polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, and polyoxyethylene polyoxypropylene glycol.

  Examples of the ester ether type surfactant include polyoxyethylene sorbitan fatty acid ester, polyoxyethylene hexitan fatty acid ester, sorbitan fatty acid ester polyethylene glycol and the like. Examples of the alkanolamide surfactant include lauric acid diethanolamide, oleic acid diethanolamide, stearic acid diethanolamide, and cocamide DEA. Examples of higher alcohol surfactants include cetanol, stearyl alcohol, and oleyl alcohol. Examples of the poloxamer type surfactant include poloxamer methacrylate.

  The concentration of the surfactant aqueous solution in the sixth step of production method 2 is preferably 0.1 to 20 g / L. Moreover, immersion conditions, such as immersion time and immersion temperature, include soaking in a solution at room temperature to 50 ° C. for 1 to 48 hours, for example.

  The seventh step of the production method 2 includes further dissolving the metal salt functioning as the catalyst 113 in the aqueous solution containing the surfactant in the sixth step or adding an aqueous solution of the metal salt. Alternatively, in addition to the aqueous solution containing the above-mentioned surfactant, an aqueous solution in which a metal salt that functions as the catalyst 113 is dissolved is prepared, and a carbon co-continuous porous body impregnated (attached) with the surfactant The carrier 111 on which 112 is supported may be immersed.

  Alternatively, an aqueous solution in which a metal salt is dissolved may be impregnated in the carrier 111 on which the carbon co-continuous porous body 112 with a surfactant attached is supported. If necessary, an alkaline aqueous solution may be dropped onto the carbon co-continuous porous body 112 containing (attached) the obtained metal salt. By these things, a metal or a metal oxide precursor can be made to adhere to the carbon co-continuous porous body 112.

  It is preferable that the addition amount of the metal salt in the 7th process of the manufacturing method 2 is an amount used as 0.1-100 mmol / L. Moreover, immersion conditions, such as immersion time and immersion temperature, include soaking in a solution at room temperature to 50 ° C. for 1 to 48 hours, for example.

  More specifically, for example, ruthenium is used as the metal. For example, a ruthenium metal salt (for example, ruthenium halide such as ruthenium chloride) contains a surfactant and is supported by the carbon co-continuous porous body 112. Is added to the aqueous solution impregnated into the prepared carrier 111. Next, an alkaline aqueous solution is dropped onto the carrier 111 on which the carbon co-continuous porous body 112 containing the ruthenium metal salt is supported, whereby ruthenium hydroxide as a metal or metal oxide precursor is converted into the carbon co-continuous porous body. 112 and carrier 111 can be carried.

  The amount of the catalyst 113 supported by the ruthenium oxide can be adjusted by the concentration of the metal salt (for example, ruthenium chloride) in the metal salt aqueous solution.

  Examples of the alkali used in the above alkaline aqueous solution include alkali metal or alkaline earth metal hydroxide, aqueous ammonia, aqueous ammonium solution, and aqueous tetramethylammonium hydroxide (TMAH) solution. The concentration of these alkaline aqueous solutions is preferably 0.1 to 10 mol / L.

  In the eighth step in the production method 2, a metal or metal oxide precursor (metal salt) attached to the surface of the carbon co-continuous porous body 112 is converted into the metal itself or the metal oxide by heat treatment.

  Specifically, the carrier 111 on which the carbon co-continuous porous body 112 with the precursor attached is supported is dried at room temperature (about 25 ° C.) to 150 ° C., more preferably at 50 ° C. to 100 ° C. for 1 to 24 hours, Next, heat treatment may be performed at 100 to 600 ° C., preferably 110 to 300 ° C.

  In the eighth step in the production method 2, the carbon co-continuous porous body 112 having the metal itself attached to the surface as the catalyst 113 was supported by heat treatment in an inert atmosphere or reducing atmosphere such as argon, helium, and nitrogen. The air electrode 101 including the carrier 111 can be manufactured. Further, by performing heat treatment in a gas containing oxygen (oxidizing atmosphere), the air electrode 101 including the carrier 111 on which the carbon co-continuous porous body 112 having the metal oxide attached to the surface as the catalyst 113 is supported is manufactured. be able to.

  Further, the heat treatment under the above-described reducing conditions is performed to once produce the carrier 111 on which the carbon co-continuous porous body 112 on which the metal itself is attached as the catalyst 113 is supported, and then this is heat-treated in an oxidizing atmosphere. Thus, it is possible to manufacture the air electrode 101 by the carrier 111 on which the carbon co-continuous porous body 112 having the metal oxide attached as the catalyst 113 is supported.

  Alternatively, the carrier 111 on which the carbon co-continuous porous body 112 to which a metal or metal oxide precursor (metal salt) is attached is dried at room temperature to 150 ° C., more preferably 50 ° C. to 100 ° C., A metal / carbon co-continuous porous body 112 / carrier 111 composite may be produced by attaching the metal itself as the catalyst 113 on the carbon co-continuous porous body 112.

  In the production method 2, the amount (content) of the catalyst 113 attached by the metal or metal oxide is 0.1 to 70 weight based on the total weight of the support 111 and the catalyst 113 on which the carbon co-continuous porous body 112 is supported. %, Preferably 1 to 30% by weight.

  According to the production method 2, the air electrode 101 in which the catalyst 113 made of metal or metal oxide is highly dispersed on the surfaces of the carbon co-continuous porous body 112 and the carrier 111 can be produced, and lithium air having excellent electrical characteristics can be produced. A secondary battery can be configured.

[Production Method 3]
Next, the manufacturing method 3 will be described. In manufacturing method 3, as described in manufacturing method 1, after preparing carrier 111 on which carbon co-continuous porous body 112 is supported, catalyst 113 is further supported on carrier 111 on which carbon co-continuous porous body 112 is supported. .

  In the manufacturing method 3, the following 6th process, 7th process, and 8th process are added in the 4th process mentioned above.

  In the sixth step, the carbon co-continuous porous body 112 and the carrier 111 are immersed in an aqueous solution of a metal salt to attach the metal salt to the surfaces of the carbon co-continuous porous body 112 and the carrier 111.

  Next, in the seventh step, the carbon co-continuous porous body 112 and the support 111 are supported on the carbon co-continuous porous body 112 and the support 111 by heat treatment of the carbon co-continuous porous body 112 and the support 111 to which the metal salt is attached.

  Next, in the eighth step, the catalyst 113 is made to be a metal oxide hydrate by allowing the carbon co-continuous porous body 112 on which the catalyst 113 is supported and the support 111 to act on high-temperature and high-pressure water.

  The above metals are titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, molybdenum, silver, cadmium, palladium, lead, ruthenium, rhodium, praseodymium, cerium, niobium, yttrium, tantalum, and tin. It is sufficient if it is at least one of the following. In particular, ruthenium is preferable.

  In the sixth step of the production method 3, an aqueous solution of a metal salt that finally becomes a metal or metal oxide precursor used as the catalyst 113 is attached (supported) on the surface of the support 111 on which the carbon co-continuous porous body 112 is supported. ) For example, an aqueous solution in which the metal salt is dissolved may be separately prepared, and the carbon co-continuous porous body 112 and the carrier 111 may be impregnated with the aqueous solution. The impregnation conditions and the like are the same as the conventional one as described above.

  The seventh step in the manufacturing method 3 is the same as the eighth step in the manufacturing method 2, and the heat treatment may be performed in an inert atmosphere or a reducing atmosphere. In addition, the carbon co-continuous porous body 112 to which the precursor is attached described as an alternative method of the eighth step of the production method 2 is heat-treated (dried) at a low temperature (room temperature to 150 ° C., more preferably 50 ° C. to 100 ° C.). By doing so, a metal may be attached to the carbon co-continuous porous body 112 and the carrier 111.

  The air electrode 101 using a metal itself as a catalyst exhibits high activity, but since the catalyst is a metal, it is vulnerable to corrosion and may lack long-term stability. On the other hand, long-term stability can be achieved by heat-treating the metal to a metal oxide hydrate by the eighth step of production method 3 described in detail below.

  In the eighth step of production method 3, the metal oxide hydrate is attached to the carbon co-continuous porous body 112 and the carrier 111. Specifically, the carbon co-continuous porous body 112 and the carrier 111 attached with the metal obtained in the seventh step of the production method 3 are immersed in high-temperature and high-pressure water, and the attached metal is converted into a metal oxide. To a catalyst 113 comprising a hydrate of

  For example, the carbon co-continuous porous body 112 and the carrier 111 to which metal is attached are immersed in water at 100 ° C. to 250 ° C., more preferably 150 ° C. to 200 ° C., and the attached metal is oxidized to form a metal oxide. Hydrate.

  Since the boiling point of water at atmospheric pressure (0.1 MPa) is 100 ° C., it cannot normally be immersed in water at 100 ° C. or higher under atmospheric pressure. By increasing the pressure to, for example, about 10 to 50 MPa, preferably about 25 MPa, the boiling point of water increases in the sealed container, and liquid water at 100 ° C. to 250 ° C. can be realized. If the carbon co-continuous porous body 112 and the carrier 111 to which the metal is attached are immersed in the high-temperature water thus obtained, the metal can be made into a metal oxide hydrate.

[Production Method 4]
Next, the manufacturing method 4 is demonstrated. In the production method 4, as described in the production method 1, after preparing the carrier 111 on which the carbon co-continuous porous body 112 is supported, the catalyst 113 is further supported on the carrier 111 on which the carbon co-continuous porous body 112 is supported. .

  In the manufacturing method 4, the following 6th process and 7th process are added in the 4th process mentioned above.

  In the sixth step, the carbon co-continuous porous body 112 and the carrier 111 are immersed in an aqueous solution of a metal salt to attach the metal salt to the surfaces of the carbon co-continuous porous body 112 and the carrier 111.

  Next, in the seventh step, the carbon co-continuous porous body 112 and the carrier 111 to which the metal salt is attached is allowed to act on high-temperature and high-pressure water to thereby form a catalyst comprising a metal oxide hydrate of the metal constituting the metal salt. 113 is supported on the carbon co-continuous porous body 112 and the carrier 111.

  The above metals are titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, molybdenum, silver, cadmium, palladium, lead, ruthenium, rhodium, praseodymium, cerium, niobium, yttrium, tantalum, and tin. It is sufficient if it is at least one of the following. In particular, ruthenium is preferable.

  The sixth step in the manufacturing method 4 is the same as the sixth step in the manufacturing method 3, and the description thereof is omitted here.

  In the seventh step in the production step 4, the precursor (metal salt) attached to the surface of the carbon co-continuous porous body 112 is converted into a metal oxide hydrate by a relatively low temperature heat treatment.

  Specifically, the carbon co-continuous porous body 112 and the carrier 111 to which the precursor is attached are dried at a relatively low temperature of about 100 to 200 ° C. Thereby, the precursor becomes a hydrate in which water molecules are present in the particles while maintaining the amorphous state of the precursor. A metal oxide hydrate obtained by such low-temperature drying is used as the catalyst 113.

  In the air electrode 101 produced by the production method 4, the metal oxide hydrate can be supported on the carbon co-continuous porous body 112 in the form of nano-sized fine particles with high dispersion. Therefore, when the carrier 111 on which such a carbon co-continuous porous body 112 is supported is the air electrode 101, excellent battery performance can be exhibited.

  The carrier 111 carrying the carbon co-continuous porous body 112 obtained by each of the above production methods and the carrier 111 carrying the carbon co-continuous porous body 112 to which the catalyst 113 is attached (supported) are carried out by known procedures. The air electrode 101 can be formed into a predetermined shape.

  For example, the catalyst-unsupported and catalyst-supported carbon co-continuous porous body 112 is processed into a plate-like body or sheet, and the obtained carbon co-continuous porous body 112 has a desired diameter (for example, 23 mm) using a punching blade, a laser cutter, or the like. The air electrode 101 may be cut out into a circular shape.

  Hereinafter, it demonstrates in detail using an Example. First, the configuration of the actually used battery will be described with reference to FIG. FIG. 2 is a cross-sectional view showing a more detailed configuration example of the lithium air secondary battery. The lithium-air secondary battery includes an air electrode 201, a negative electrode 202, an electrolyte 203, a separator 204, an air electrode support 205, an air electrode fixing ring 206, a negative electrode fixing ring 207, a negative electrode fixing washer 208, and a negative electrode support 209. , Fixing screw 210, O-ring 211, air electrode terminal 221, and negative electrode terminal 222.

  The air electrode 201, the negative electrode 202, the electrolyte 203, and the separator 204 are accommodated in a cylindrical air electrode support 205. The air electrode support 205 has a partition 251 at the center in the cylinder, and is partitioned into a first region 205 a where the air electrode 201 is disposed and a second region 205 b where the negative electrode 202 and the separator 204 are disposed. ing. The partition 251 has an opening at the center, and the first region 205a and the second region 205b communicate with each other through the opening.

The liquid electrolyte 203 is disposed in the opening of the partition 251 and is sandwiched between the air electrode 201 and a separator 204 serving as a salt bridge. The separator 204 is impregnated with the electrolyte 203. Note that the electrolyte 203 is also disposed around the separator 204. The electrolyte 203 is a 1 mol / L lithium bistrifluoromethanesulfonylimide / propylene carbonate [(CF ₃ SO ₂ ) ₂ NLi / PC] solution.

The air electrode 201 is sandwiched between an air electrode fixing ring 206 made of polytetrafluoroethylene (PTFE) and a partition 251, and is fixed to a first region 205 a in the cylinder of the air electrode support 205. Yes. In the opening of the air electrode fixing ring 206, the effective area of the electrode in contact with the air electrode 101 and air is 2 cm ² . On the other hand, the separator 204 is sandwiched between a negative electrode fixing ring 207 made of PTFE and a partition 251, and is fixed to a second region 205 b in the cylinder of the air electrode support 205. In this way, the liquid electrolyte 203 is sealed between the air electrode 201 and the separator 204 at the opening of the partition 251.

The negative electrode 202 has a negative electrode fixing washer 208 laminated inside a negative electrode fixing ring 207, and a negative electrode support 209 made of a metal covered thereon. The negative electrode 202 is configured by concentrating four metal lithium foils having a thickness of 150 μm on concentric circles, and is pressure-bonded to the negative electrode fixing washer 208. The negative electrode 202 has an effective area of 2 cm ² . The negative electrode support 209 is fixed to the air electrode support 205 by a fixing screw 210. Further, an O-ring 211 is disposed between the air electrode support 205 and the negative electrode support 209.

  The negative electrode 202 is pressed in the direction of the separator 204 through the negative electrode fixing washer 208 by the negative electrode support 209 pressed against the air electrode support 205 by the fixing screw 210, and is pressed against the separator 204. The lithium air secondary batteries having these configurations were produced in dry air having a dew point of −60 ° C. or lower.

  Although the air electrode support 205 is made of metal, although not shown, it is covered with PTFE and insulated and separated from the electrolyte 203, the separator 204, and the like. Note that the portion where the air electrode 201 and the air electrode support 205 are in contact with each other is not covered with PTFE in order to make electrical contact. Further, although not shown, the fixing screw 210 made of metal is covered with PTFE so that the air electrode support 205 and the negative electrode support 209 are electrically separated.

[Example 1]
First, Example 1 will be described. Example 1 is an example in which a carrier on which a carbon co-continuous porous body having a three-dimensional network structure is supported is used as an air electrode. A carrier on which a carbon co-continuous porous body having a three-dimensional network structure used as an electrode of an air electrode was supported was synthesized as follows.

  Commercially available polyacrylonitrile (average molecular weight 150,000; manufactured by Sigma-Aldrich) was added at a concentration of 85 mg / ml to dimethyl sulfoxide (DMSO) solvent, which is a good solvent for polyacrylonitrile, and dissolved by stirring at 50 ° C. . After complete dissolution, an appropriate amount of the solution was taken out on a commercially available carbon sheet (manufactured by Toray Industries, Inc.) and applied uniformly onto the carbon sheet using a spatula.

  The coating film applied on the carbon sheet as described above was exposed to water, which is a poor solvent for polyacrylonitrile, at a flow rate of 2 L / min for 15 minutes. As a result of this treatment, polyacrylonitrile that could not be dissolved was deposited around water droplets as a poor solvent, and a white polyacrylonitrile co-continuous porous body (solid) was formed on the carbon sheet. This was followed by vacuum drying overnight at room temperature. The carbon sheet (carrier | carrier) which carry | supported the polyacrylonitrile co-continuous porous body by the above was obtained.

  Next, a crystallization treatment was performed in which the carbon sheet carrying the polyacrylonitrile co-continuous porous material was placed in a nitrogen atmosphere at 230 ° C. for 60 minutes. Thereafter, the polyacrylonitrile co-continuous porous material supported on the carbon sheet was carbonized (carbonized) by heating to 1000 ° C. at a rate of 4 ° C./min in a carbon dioxide atmosphere.

The carbon sheet carrying the carbon co-continuous porous material obtained by carbonization was evaluated by performing X-ray diffraction (XRD) measurement, scanning electron microscope (SEM) observation, and BET specific surface area measurement. The produced carbon sheet carrying the carbon co-continuous porous material was confirmed to be a single phase of carbon (C, PDF card No. 01-071-4630) by XRD measurement. Moreover, it was confirmed by SEM observation that a co-continuous porous body in which the particles are continuously connected and the average pore diameter is 1 μm is supported on the carbon fibers forming the carbon sheet. Moreover, it was 150 m < ² > / g when the specific surface area of the carbon co-continuous porous body was measured by BET method. The average pore diameter was determined by mercury porosimetry for the carrier 111 on which the carbon co-continuous porous body 112 was supported. The same applies to the following embodiments.

  The carbon sheet carrying the carbon co-continuous porous body was cut into a circle having a diameter of 23 mm with a punching blade, a laser cutter, or the like to obtain a gas diffusion type air electrode.

  The battery performance of the lithium air secondary battery cell constituted by the obtained air electrode of Example 1 was measured. In the battery performance measurement test, the air electrode terminal 221 and the negative electrode terminal 222 were used.

In the battery cycle test, a commercially available charge / discharge measurement system (BioLogic, VMP-3) was used, and a current density of 0.1 mA / cm ² per effective area of the air electrode was applied. However, it measured until it fell to 2.0V. Charging was performed at the same current density until the battery voltage increased to 4.2V. The charge / discharge capacity was expressed as a value (mAh / g) per weight of the air electrode of Example 1. The initial discharge and charge curves are shown in FIG. In FIG. 3, the discharge is indicated by a broken line and the charge is indicated by a solid line. The battery charge / discharge test was performed under a normal living environment (normal temperature and atmospheric pressure).

  As shown in FIG. 3, it can be seen from the air electrode of Example 1 that the lithium-air secondary battery cell has an average discharge voltage of 2.7 V and a discharge capacity of 950 mAh / g. The average discharge voltage is the battery voltage when the discharge amount is ½ (475 mAh / g in this embodiment) of the battery discharge capacity (950 mAh / g in this embodiment). In addition, the initial charge capacity is 850 mAh / g, which is almost the same as the discharge capacity, and it can be seen that the reversibility is excellent. Moreover, about the voltage at the time of charge, it turned out that a flat part is seen by about 3.5V from FIG. 3, and shows a value lower than the conventional report.

  The transition of charge / discharge voltage is shown in Table 1 below. Table 1 is shown after the description of Comparative Example 2. In Example 1, although a slight increase in overvoltage was observed during charging / discharging, it was found that a substantially stable voltage was exhibited. Thus, it was found that the carbon sheet on which the carbon co-continuous porous material was supported had very excellent stability as the air electrode of the lithium air secondary battery.

  The cycle dependency of the discharge capacity is shown in FIG. As shown in Table 2, the lithium-air secondary battery of Example 1 shown after the description of Comparative Example 2 is the same as Comparative Example 1 evaluated for a lithium-air secondary battery with an air electrode using powdered carbon described later. In comparison, the slope of the decrease in discharge capacity (mAh / g) became gentle, and a cycle test was possible even after repeating the charge / discharge cycle 100 times.

[Example 2]
Next, Example 2 will be described. In Example 2, a carbon sheet carrying a carbon co-continuous porous material containing a transition metal oxide as a catalyst was used as an air electrode.

A gas diffusion type air electrode was prepared using a technique in which a transition metal oxide is supported on a carbon sheet on which a carbon co-continuous porous material is supported. In the following, a production method for supporting a catalyst made of RuO ₂ will be shown as a representative, but a transition metal oxide can be supported by changing Ru to an arbitrary transition metal. The transition metal oxides used as catalysts are as shown in Tables 2 and 3.

  The evaluation method of the carbon sheet on which carbon co-continuous pores were supported, the production method of the electrode and the battery, and these evaluation methods were performed in the same manner as in Example 1. The carbon sheet on which the carbon co-continuous porous material was supported was produced in the same manner as the first process shown in Example 1.

After producing a carbon sheet carrying a carbon co-continuous porous material, commercially available ruthenium chloride (RuCl ₃ ; manufactured by Furuya Metal Co., Ltd.) was dissolved in distilled water, and the produced carbon co-continuous porous material was carried in this aqueous solution. Carbon sheets were impregnated and ruthenium chloride was supported on them.

Next, ammonia water (28%) was gradually added dropwise to the carbon co-continuous porous material and the carbon sheet carrying ruthenium chloride until the pH reached 7.0, thereby precipitating ruthenium hydroxide. The precipitate was repeatedly washed with distilled water five times so that no chlorine remained. The carbon co-continuous porous body and the carbon sheet adhered (supported) with ruthenium hydroxide thus obtained were heat-treated at 500 ° C. for 6 hours in an argon atmosphere, and the carbon co-continuous porous body to which a RuO ₂ catalyst was adhered. Was produced.

The carbon sheet carrying the carbon co-continuous porous material to which the catalyst made of RuO ₂ is attached is evaluated by XRD measurement, thermogravimetric / differential heat (TG-DTA) analysis, and transmission electron microscope (TEM) observation. did.

From XRD measurement. A peak of ruthenium oxide (RuO ₂ , PDF file No. 40-1290) was observed, and it was confirmed that the supported catalyst was a ruthenium oxide single phase. Moreover, it was confirmed by the TG-DTA measurement that the carbon sheet on which the carbon co-continuous porous material was supported and RuO ₂ were not hydrated. By TEM observation, it was observed that the RuO ₂ catalyst was precipitated in the form of particles having an average particle diameter of 100 nm on the surface of the carbon co-continuous porous body. In addition, the average particle diameter (average particle diameter) was expanded by SEM and the diameter of particles per 10 μm square (10 μm × 10 μm) was measured to obtain an average value. The same applies to the following embodiments.

The cycle dependency of the discharge capacity and charge / discharge voltage of the lithium-air secondary battery using the carbon sheet carrying the carbon co-continuous porous material carrying RuO ₂ as a catalyst in Example 2 described above as the air electrode. FIG. 4, Table 1, Table 2 and Table 3 show.

  As shown in FIG. 4, in Example 2, the discharge capacity was 1320 mAh / g for the first time, which was larger than that in the case where the catalyst as in Example 1 was not used. Moreover, in Example 2, even if it repeated the cycle of charging / discharging, it turned out that the stable behavior is shown. In addition, as shown in Table 1, the charge / discharge voltage was also reduced more than in Example 1, and an improvement in charge / discharge energy efficiency was achieved. Further, regarding the charge / discharge voltage, no significant increase in overvoltage was observed even when the cycle was repeated, and it was confirmed that the lithium-air secondary battery of Example 2 operated stably.

The improvement of the characteristics in Example 2 described above is that the reaction of oxygen reduction (discharge) and oxygen generation (charge) can be smoothly performed at the air electrode by using RuO ₂ having very large activity as an electrode catalyst. This is thought to be due to the fact that

  In Tables 2 and 3, the metal oxides constituting the catalyst in Example 2 are titanium oxide, vanadium oxide, chromium oxide, manganese oxide, iron oxide, cobalt oxide, nickel oxide, copper oxide, zinc oxide, molybdenum oxide, Cycle dependence of discharge capacity and charge / discharge voltage when using silver oxide, cadmium oxide, palladium oxide, lead oxide, ruthenium oxide, rhodium oxide, praseodymium oxide, cerium oxide, niobium oxide, yttrium oxide, tantalum oxide, tin oxide Indicates.

As in the case of RuO ₂ as a representative example of Example 2, the discharge capacity shows about 1000 mAh / g for the first time regardless of which metal oxide is used. The value was larger than when not used. In the case of these metal oxides, as in the case of RuO ₂ , it is considered that the battery characteristics were improved by functioning efficiently as a catalyst.

[Example 3]
Next, Example 3 will be described. In Example 3, an air electrode is constituted by a carbon sheet on which a carbon co-continuous porous body using a metal oxide hydrate as a catalyst is supported. As the catalyst, ruthenium oxide hydrate (RuO ₂ .nH ₂ O) was used. RuO ₂ .nH ₂ O was synthesized by the process shown in Example 2 without performing the final heat treatment at 500 ° C. for 6 hours. The carbon co-continuous porosity evaluation method and the electrode and battery production method and evaluation method were performed in the same manner as in Example 1.

From the XRD measurement, it was confirmed that the obtained RuO ₂ · nH ₂ O was amorphous. The amount of water molecules of RuO ₂ · nH ₂ O was found to be n = 0.5 from TG-DTA measurement. By TEM observation, it was observed that the catalyst based on RuO ₂ · nH ₂ O was precipitated in the form of particles having an average particle diameter of 50 nm on the surface of the carbon co-continuous porous body.

FIG. 4, Table 1 and Table 3 show the cycle dependency of the discharge capacity and charge / discharge voltage of the lithium-air secondary battery of Example 3 using RuO ₂ .0.5H ₂ O as the electrode catalyst for the air electrode.

As shown in FIG. 4, the discharge capacity in Example 3 was 1460 mAh / g for the first time, which was a larger value than that in the case of using RuO ₂ that was not hydrated as in Example 2 as a catalyst. It was also found that even when the cycle was repeated, stable behavior was exhibited.

The improvement in characteristics in Example 3 as described above is considered because the deposition site of lithium oxide during discharge increased because the electrode catalyst made of RuO ₂ .0.5H ₂ O had a very large surface area. It is done. Further, it is considered that the oxygen adsorption ability was improved and the oxygen functioned efficiently.

[Example 4]
Next, Example 4 will be described. Example 4 is an example of a lithium-air secondary battery using, as an air electrode, a carbon co-continuous porous body containing ruthenium metal as a catalyst or a carbon sheet carrying a carbon co-continuous porous body containing ruthenium oxide as a catalyst. is there.

As a manufacturing method of the air electrode, the following method was used as a method of attaching metal Ru or RuO ₂ to a carbon sheet on which a carbon co-continuous porous body was supported.

  The carbon co-continuous porosity evaluation method, the electrode and battery production methods, and these evaluation methods were carried out in the same manner as in Example 1. The carbon co-continuous porous material was produced in the same manner as in the first process shown in Example 1.

  Next, poloxamer methacrylate (Pluronic-F127, manufactured by Aldrich), a block copolymer of poloxamer, which is a surfactant, is dissolved in distilled water at a concentration of 5 mg / ml, and the carbon co-continuous porous material is supported on this solution. The carbon sheet was immersed and stirred with a shaker for 24 hours to disperse the surfactant in the pores of the porous body.

Next, 0.1 mol / L aqueous solution of ruthenium chloride (RuCl ₃ ; manufactured by Furuya Metal Co., Ltd.) was added to the above solution and stirred for 24 hours with a shaker to impregnate the porous body with ruthenium chloride salt. Thereafter, the carbon sheet carrying the carbon co-continuous porous body is evaporated to dryness at 50 ° C., heat treated at 300 ° C. in a nitrogen atmosphere to remove the surfactant, and the carbon co-continuous porous body to which the metal Ru is adhered is obtained. Obtained.

  By XRD measurement, it was confirmed that the obtained metal Ru was a ruthenium metal single phase (Ru, PDF card No. 01-070-0274). By TEM observation, it was confirmed that the catalyst composed of Ru was uniformly deposited with an average particle diameter of 2 nm up to the pores of the carbon co-continuous porous body.

Next, the metal Ru obtained as described above was heated in air at 300 ° C. for 12 hours. From XRD measurement, it was confirmed that the obtained RuO ₂ was amorphous. Further, TEM observation confirmed that the catalyst composed of RuO ₂ was uniformly deposited with an average particle diameter of 5 nm in the pores as in the case of the carbon co-continuous porous body to which the Ru catalyst was attached.

FIG. 4, Table 1, and Table 3 show the cycle dependency of the discharge capacity and the charge / discharge voltage of the lithium-air secondary battery using the metal Ru and RuO ₂ produced by the above-described manufacturing method as an electrode catalyst for the air electrode. .

As shown in FIG. 4, the discharge capacity of Example 4 was 2640 mAh / g for the first time for metal Ru, and 2170 mAh / g for the first time for RuO ₂ . This was a larger value for both the metal Ru and RuO ₂ than when RuO ₂ not using the production method of the present invention as in Example 3 was used as a catalyst. Further, both metal Ru and RuO ₂ showed high discharge capacity even after 100 cycle tests.

In the carbon sheet on which the carbon co-continuous porous body containing metal Ru is supported, the catalyst is a metal, so that the metal ruthenium is easily eluted in the form of ruthenium ions in the electrolytic solution, and is vulnerable to corrosion. Therefore, compared to RuO _2, long-term stability is lowered. However, as is apparent from FIG. 4, the discharge capacity is superior to the carbon sheet carrying the carbon co-continuous porous material containing the ruthenium catalyst obtained by the conventional method.

  Moreover, as shown in Table 1, also about charge / discharge voltage, the reduction of overvoltage was seen rather than Example 3, and it turns out that the energy efficiency of charge / discharge is improved. In addition, regarding the charge / discharge voltage, it was confirmed that no significant overvoltage increase was observed even when the cycle was repeated, and the operation was stable.

By the production method of the present invention described above, the metal Ru and RuO _{2 as} the electrode catalyst are supported in a highly dispersed state on the carbon co-continuous porous material having a large specific surface area, and the ratio of ruthenium oxide is reduced by low-temperature heat treatment. Increases surface area. With such a large specific surface area, an increase in lithium oxide deposition sites during discharge and an improvement in oxygen adsorption capacity are realized. The improvement in the characteristics as described above is considered to be caused by various improvements based on the production method of the present invention.

[Example 5]
Next, Example 5 will be described. Example 5 is an example of a lithium-air secondary battery in which a carbon co-continuous porous material containing ruthenium oxide hydrate prepared from high-temperature and high-pressure water as a catalyst is used as an air electrode.

As a manufacturing method of the air electrode in Example 5, the following method was used as a method of further supporting a catalyst made of RuO ₂ · nH ₂ O on a carbon sheet on which a carbon co-continuous porous material was supported.

  The evaluation method of the carbon sheet carrying the carbon co-continuous pores, the electrode and battery manufacturing methods, and these evaluation methods were performed in the same manner as in Example 1. The carbon sheet on which the carbon co-continuous porous material was supported was produced in the same manner as the first process shown in Example 1.

  Next, a carbon co-continuous porous body carrying a highly dispersed catalyst made of Ru was produced in the same manner as in Example 4.

  Next, in a closed vessel for hydrothermal synthesis, a carbon co-continuous porous material carrying a metal Ru obtained by producing in the same manner as in Example 4 and distilled water are housed, and under an autogenous pressure (about 12 to 20 MPa). Heated at 180 ° C. for 24 hours.

The carbon sheet carrying the carbon co-continuous porous material taken out from the sealed container after the above treatment was vacuum-dried at room temperature. From the XRD measurement, it was confirmed that the obtained ruthenium oxide was an amorphous hydrate (RuO ₂ .nH ₂ O). The amount of water molecules of RuO ₂ · nH ₂ O was found to be n = 0.7 from TG-DTA measurement.

As a result of TEM observation, a catalyst composed of RuO ₂ · nH ₂ O was uniformly deposited with an average particle diameter of 4 nm into the pores, as in the case of a carbon sheet carrying a carbon co-continuous porous material containing a catalyst composed of Ru. It was confirmed that

The cycle dependency of the discharge capacity and the charge / discharge voltage of the lithium-air secondary battery using RuO ₂ .0.7H ₂ O as an electrode catalyst for the air electrode in Example 4 produced by the manufacturing method described above is shown in FIG. 1, shown in Table 3.

As shown in FIG. 4, the discharge capacity of the lithium-air secondary battery cell in Example 5 was 2420 mAh / g for the first time. This was a larger value than when RuO ₂ produced by oxidizing in air without using high-temperature and high-pressure water as in Example 4 was used as a catalyst. Moreover, it confirmed that it act | operated stably also regarding the cycle of charging / discharging.

  Moreover, as shown in Table 1, also about charge / discharge voltage, the reduction of overvoltage was seen rather than Example 3, and it turns out that the energy efficiency of charge / discharge is improved. In addition, regarding the charge / discharge voltage, it was confirmed that no significant overvoltage increase was observed even when the cycle was repeated, and the operation was stable.

In addition, by using high-temperature and high-pressure water instead of oxidation by heat treatment in air as in Example 4, it became possible to lower the oxidation temperature and to obtain a hydrate. Therefore, these increase the specific surface area of the catalyst (catalyst particles) and improve the catalytic activity, and RuO ₂ produced by oxidizing in air without using high-temperature and high-pressure water as in Example 4 was used as the catalyst. It is considered that a larger discharge capacity was realized than in the case.

[Comparative Example 1]
Next, Comparative Example 1 will be described. In Comparative Example 1, a lithium-air secondary battery cell using carbon (Ketjen Black EC600JD) and RuO ₂ was manufactured and evaluated.

Lithium-air secondary battery cells were produced as follows using carbon (Ketjen Black EC600JD) and RuO ₂ which are known as electrodes for the air electrode.

RuO ₂ powder, Ketjen black powder (manufactured by Lion) and polytetrafluoroethylene (PTFE) powder (manufactured by Daikin) in a weight ratio of 50:30:20 are thoroughly pulverized and mixed using a milling machine. Was formed into a sheet electrode (thickness: 0.5 mm). The sheet electrode was cut into a circle having a diameter of 23 mm and pressed onto a titanium mesh to obtain a gas diffusion type air electrode. As RuO ₂ , a commercially available reagent (manufactured by High Purity Chemical Laboratory) was used. Moreover, the conditions of the cycle test of the produced lithium air secondary battery cell are the same as in Example 1.

  The cycle performance related to the discharge capacity of the lithium air secondary battery according to Comparative Example 2 is shown in FIGS.

  As shown in FIG. 4, the initial discharge capacity of Comparative Example 1 was 910 mAh / g, which was smaller than that of Example 1. Moreover, when the charge / discharge cycle was repeated, unlike Examples 1 to 4, an extreme decrease in the discharge capacity was observed, and the capacity retention rate after 20 cycles was about 20% of the initial value.

  The cycle dependency of the charge / discharge voltage is shown in Table 1 together with the results of Examples 1 to 4. As shown in Table 1, the charge / discharge overvoltage according to Comparative Example 1 is higher than those of Examples 1 to 4, and when the cycle is repeated, the overvoltage clearly increases and the charge / discharge is difficult at the 20th time. It became. In addition, when the air electrode was observed after the measurement, a part of the air electrode collapsed and dispersed in the electrolytic solution, and it was seen that the electrode structure of the air electrode was destroyed.

From the results of Comparative Example 1 described above, the air electrode including the carbon sheet on which the carbon co-continuous porous material containing RuO ₂ is supported as in the present invention is superior in cycle characteristics with respect to capacity and voltage than known materials. It was confirmed that it is effective as an air electrode for a lithium-air secondary battery.

[Comparative Example 2]
Comparative Example 2 exemplifies a lithium-air secondary battery using a carbon co-continuous porous material containing RuO ₂ as an air electrode. In Comparative Example 2, a carbon co-continuous porous material was used alone without using a carrier.

The carbon co-continuous porosity evaluation method containing RuO ₂ , the electrode and battery fabrication methods, and these evaluation methods were performed in the same manner as in Example 2. The carbon co-continuous porous material containing RuO ₂ was prepared by dissolving polyacrylonitrile in the process shown in Example 2 instead of applying a dimethyl sulfoxide solution in which polyacrylonitrile was dissolved to a carbon sheet and exposing it to running water. An appropriate amount of the dimethyl sulfoxide solution was taken out into a container such as a petri dish, and sprayed with water, which is a poor solvent, using a spray bottle.

  The cycle performance regarding the discharge capacity of the lithium air secondary battery according to Comparative Example 2 is shown in FIG. 4 and Table 3 together with the results of Examples 1 to 4 and Comparative Example 1.

  As shown in FIG. 4, the initial discharge capacity of Comparative Example 2 was 910 mAh / g, which was smaller than that of Example 1. When the charge / discharge cycle was repeated, the capacity retention rate after 20 cycles of the discharge capacity was about 50% of the initial value.

  The cycle dependency of the charge / discharge voltage in Comparative Example 2 is shown in Table 1 together with the results of Examples 1 to 4 and Comparative Example 1.

  As can be seen from Table 1, the charge / discharge overvoltage according to Comparative Example 2 is higher than those in Examples 1 to 4, and the overvoltage clearly increases when the cycle is repeated, and charging / discharging becomes difficult at the 75th time. It was. In addition, when the air electrode was observed after the measurement, the air electrode was cracked. It is considered that the fracture occurred due to the application of pressure from the evaluation cell during measurement. It is considered that the conductive path between the carbon particles is cut by this breakage, and the cycle characteristics are lower than those of Examples 1 to 4.

  From the above results, the lithium-air secondary battery using the air electrode constituted by the carrier on which the carbon co-continuous porous material is supported as in the present invention has cycle characteristics with respect to capacity and voltage, compared to the case of using known materials. It was confirmed that it was excellent and effective as an air electrode for a lithium air secondary battery.

  As described above, according to the present invention, since the air electrode is composed of the porous support and the carbon co-continuous porous body having a three-dimensional network structure continuously supported over the entire area of the support, the lithium air secondary The charge / discharge cycle performance and energy efficiency of the battery can be increased and the discharge capacity can be increased. ADVANTAGE OF THE INVENTION According to this invention, the lithium air secondary battery excellent in charging / discharging cycling performance can be produced, and the produced lithium air secondary battery can be utilized effectively as a drive source of various electronic devices.

  The present invention is not limited to the embodiment described above, and many modifications and combinations can be implemented by those having ordinary knowledge in the art within the technical idea of the present invention. It is obvious.

  DESCRIPTION OF SYMBOLS 101 ... Air electrode, 102 ... Negative electrode, 103 ... Electrolyte, 111 ... Support | carrier, 112 ... Carbon co-continuous porous body, 113 ... Catalyst.

Claims (8)

An air electrode composed of a porous carbon body and a carbon co-continuous porous body composed of carbon having a three-dimensional network structure continuously supported over the entire area of the carrier;
A negative electrode comprising lithium;
An lithium-air secondary battery, comprising: an electrolyte disposed between the air electrode and the negative electrode. The lithium air secondary battery according to claim 1,
Comprising a catalyst carried on the air electrode,
The catalyst is titanium oxide, vanadium oxide, chromium oxide, manganese oxide, iron oxide, cobalt oxide, nickel oxide, copper oxide, zinc oxide, molybdenum oxide, silver oxide, cadmium oxidation At least one metal oxide of oxide, palladium oxide, lead oxide, ruthenium oxide, rhodium oxide, praseodymium oxide, cerium oxide, niobium oxide, yttrium oxide, tantalum oxide, and tin oxide A lithium-air secondary battery characterized by being configured. The lithium air secondary battery according to claim 2,
The lithium-air secondary battery, wherein the metal oxide is a hydrate containing water molecules. The lithium air secondary battery according to claim 1,
Comprising a catalyst carried on the air electrode,
The catalyst includes at least titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, molybdenum, silver, cadmium, palladium, lead, ruthenium, rhodium, praseodymium, cerium, niobium, yttrium, tantalum, and tin. A lithium-air secondary battery comprising a single metal. A first step of dissolving polyacrylonitrile in a good solvent for polyacrylonitrile to obtain a high molecular weight solution;
A second step of applying the high molecular weight solution to a porous carrier;
A third step of depositing a polymer co-continuous porous body having a three-dimensional network structure continuously supported over the entire area of the carrier by exposing the carrier coated with the polymer solution to a poor solvent for polyacrylonitrile;
By heat-treating the polymer co-continuous porous material supported on the carrier to form a carbon co-continuous porous material having a three-dimensional network structure, the carbon co-continuous material of the three-dimensional network structure continuously supported over the entire area of the carrier A fourth step of producing an air electrode made of a porous body;
And a fifth step of producing a lithium-air secondary battery comprising the air electrode, a negative electrode including lithium, and an electrolyte disposed between the air electrode and the negative electrode. A method for producing a lithium air secondary battery. In the manufacturing method of the lithium air secondary battery according to claim 5,
The fourth step includes
A sixth step of immersing the carrier carrying the carbon co-continuous porous body in an aqueous solution of a surfactant to attach the surfactant to the surface of the carbon co-continuous porous body and the carrier;
A seventh step of attaching the metal salt to the surface of the carbon co-continuous porous body to which the surfactant is attached using an aqueous solution of the metal salt and the carrier with the surfactant;
A catalyst comprising the metal constituting the metal salt or the oxide of the metal is supported on the carbon co-continuous porous body and the support by heat treatment on the carbon co-continuous porous body and the support to which the metal salt is attached. Process and
The metal is at least titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, molybdenum, silver, cadmium, palladium, lead, ruthenium, rhodium, praseodymium, cerium, niobium, yttrium, tantalum, and tin. A method for producing a lithium-air secondary battery, characterized in that one is provided. In the manufacturing method of the lithium air secondary battery according to claim 5,
The fourth step includes
A sixth step of immersing the carbon co-continuous porous body and the carrier in an aqueous solution of a metal salt to attach the metal salt to the surfaces of the carbon co-continuous porous body and the carrier;
A seventh step in which a catalyst comprising a metal constituting the metal salt is supported on the carbon co-continuous porous body and the support by heat treatment on the carbon co-continuous porous body and the support to which the metal salt is attached;
And an eighth step of making the catalyst a metal oxide hydrate by allowing the carbon co-continuous porous material on which the catalyst is supported and the support to act on high-temperature and high-pressure water,
The metal is at least titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, molybdenum, silver, cadmium, palladium, lead, ruthenium, rhodium, praseodymium, cerium, niobium, yttrium, tantalum, and tin. A method for producing a lithium-air secondary battery, characterized in that one is provided. In the manufacturing method of the lithium air secondary battery according to claim 5,
The fourth step includes
A sixth step of immersing the carbon co-continuous porous body and the carrier in an aqueous solution of a metal salt to attach the metal salt to the surfaces of the carbon co-continuous porous body and the carrier;
The carbon co-continuous porous body to which the metal salt is attached and the support are allowed to act on high-temperature and high-pressure water, whereby a catalyst comprising a metal oxide hydrate of the metal constituting the metal salt is converted into the carbon co-continuous porous And a seventh step of supporting the body and the carrier,
The metal is at least titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, molybdenum, silver, cadmium, palladium, lead, ruthenium, rhodium, praseodymium, cerium, niobium, yttrium, tantalum, and tin. A method for producing a lithium-air secondary battery, characterized in that one is provided.