JP2012084490A - Lithium gas battery - Google Patents

Abstract

A lithium gas battery capable of increasing a discharge start voltage is provided.
A negative electrode 1 having a negative electrode active material capable of occluding and releasing lithium ions, a positive electrode 2 using a gas capable of oxidation and reduction as a positive electrode active material, and non-aqueous ions disposed between the negative electrode and the positive electrode A lithium gas battery 10 including the conductor 3 and containing a redox catalyst prepared by firing a metal phthalocyanine complex supported on a carrier on the positive electrode is provided. By firing, the bond between the carrier and the metal phthalocyanine complex is strengthened, and the discharge start voltage can be increased.
[Selection] Figure 1

Description

  The present invention relates to a lithium gas battery including a negative electrode capable of occluding and releasing lithium ions and using a gas capable of oxidation and reduction as a positive electrode active material.

  A battery using lithium as an active material has high energy density and can be operated at a high voltage. For this reason, it is used in information equipment such as a mobile phone as a battery that can be easily reduced in size and weight, and in recent years, there is an increasing demand for a large-sized power source such as a hybrid vehicle.

  Among such batteries, a lithium ion secondary battery includes a positive electrode and a negative electrode, and an electrolyte filled therebetween, and the electrolyte is composed of a non-aqueous liquid, a solid, or the like. The manufactured lithium ion secondary battery is discharged after being charged, and is regenerated by charging after discharging. At the time of charge / discharge of the lithium ion secondary battery, lithium ions move between the positive electrode and the negative electrode.

  On the other hand, a battery (hereinafter referred to as a “gas battery”) using a gas capable of oxidation and reduction as represented by oxygen, nitrogen, air, or the like as a positive electrode active material takes in the gas from the outside during discharge. Therefore, it is possible to increase the proportion of the negative electrode active material in the battery container as compared with other batteries having the positive electrode active material and the negative electrode active material in the battery. Therefore, it is easy to increase the electric capacity that can be discharged, and it is easy to reduce the size and weight. Further, for example, when oxygen is used as a gas, the oxidizing power of oxygen is strong, so that the electromotive force of the battery is relatively high. In addition, gases such as oxygen, nitrogen, and air have a characteristic that they are clean materials without resource limitations. Therefore, the environmental impact of the gas battery is small. As described above, the gas battery having many advantages is expected to be used for a battery for a hybrid vehicle, a battery for a portable device, and the like, and in recent years, high performance of the gas battery is demanded.

  As a technique related to such a gas battery, for example, in Patent Document 1, a container, a positive electrode that is housed in the container and includes an active material, a negative electrode that is housed in the container, and a positive electrode and a negative electrode are disposed. A non-aqueous electrolyte air battery comprising a non-aqueous electrolyte layer and an air hole formed in a container and taking in oxygen into a positive electrode, wherein the active material is 20% by weight or more of a phthalocyanine derivative having an amorphous structure and 20 The total amount of the derivative having an amorphous structure contained in the active material is 3 to 50% by weight, containing 3 to 50% by weight of at least one of the naphthocyanine derivatives having an amorphous structure by weight% or more. A featured non-aqueous electrolyte air battery is disclosed.

JP 2004-63262 A

  The technique disclosed in Patent Document 1 has a problem that the bonding between the carbon material and the oxygen-activated catalyst supported on the carbon material tends to be insufficient, and the discharge start voltage tends to decrease.

  Then, this invention makes it a subject to provide the lithium gas battery which can make discharge start voltage high.

In order to solve the above problems, the present invention takes the following means. That is,
The present invention relates to a negative electrode having a negative electrode active material capable of occluding and releasing lithium ions, a positive electrode using a gas capable of oxidation and reduction as a positive electrode active material, and a non-aqueous ionic conductor disposed between the negative electrode and the positive electrode And a positive electrode contains a redox catalyst prepared by firing a metal phthalocyanine complex supported on a carrier, and is a lithium gas battery.

  Here, the “oxidizable gas” refers to, for example, a gas (for example, air) in which two or more of these are mixed in addition to oxygen, nitrogen, carbon dioxide, and hydrogen. The “lithium gas battery” refers to a battery using a gas capable of oxidation and reduction as a positive electrode active material and a material capable of occluding and releasing lithium ions as a negative electrode active material. That is, for example, a lithium air battery using air as a positive electrode active material and metal lithium as a negative electrode active material is included in the lithium gas battery of the present invention.

  In the present invention, the central metal of the metal phthalocyanine complex is preferably Fe or Co.

  Moreover, in the said invention, it is preferable that the central metal of a metal phthalocyanine complex is Fe, and sulfur is added to this metal phthalocyanine complex.

  In the present invention, the molar ratio N / C of nitrogen and carbon constituting the fired metal phthalocyanine complex is preferably 0.005 <N / C <0.013.

  The lithium gas battery of the present invention contains a redox catalyst produced by firing a metal phthalocyanine complex supported on a carrier on a positive electrode, and the fired metal phthalocyanine complex is a gaseous redox catalyst. Function as. By firing, it becomes possible to increase the rate of occurrence of the two-electron reduction reaction by strengthening the bonding between the support and the metal phthalocyanine complex, and thus it is possible to increase the discharge start voltage. Therefore, according to this invention, the lithium gas battery which can make discharge start voltage high can be provided.

  In the present invention, since the central metal of the metal phthalocyanine complex is Fe or Co, it becomes easy to increase the discharge start voltage.

  In the present invention, the central metal of the metal phthalocyanine complex is Fe, and sulfur is added to the metal phthalocyanine complex, so that in addition to the above effects, the Coulomb efficiency (= charge capacity / It is possible to increase the discharge capacity.

  Further, in the present invention, since the molar ratio N / C of nitrogen and carbon constituting the fired metal phthalocyanine complex is 0.005 <N / C <0.013, in addition to the above effects, the fired Further, the redox activity of the metal phthalocyanine complex can be enhanced.

It is a figure explaining the lithium gas battery 10 of this invention. It is a figure which shows the mode before and behind baking of the metal phthalocyanine complex which the center metal carry | supported by activated carbon is Fe. It is a figure which shows the mode before and behind baking of the metal phthalocyanine complex which the center metal carry | supported by activated carbon is Co. It is sectional drawing of the produced cell 40 for evaluation. It is a figure which shows the result of a discharge test. It is a figure which shows the result of a discharge test. It is a figure which shows the result of a discharge test. It is a figure which shows the result of a discharge test. It is a figure which shows the result of a charge test. It is a figure which shows the result of a charge test. It is a figure which shows the result of a charge test. It is a figure which shows the result of a charge test. It is a figure which shows the result of a discharge test. It is a figure which shows the relationship between molar ratio N / C and discharge capacity. It is a figure which shows the relationship between molar ratio N / C and charge capacity.

  As a result of diligent research, the present inventor has found that a metal phthalocyanine complex (hereinafter referred to as “Fe phthalocyanine”) whose central metal is supported on a carbon support is a metal phthalocyanine complex (hereinafter referred to as “Fe phthalocyanine”). Lithium gas batteries that include “Co phthalocyanine” in the positive electrode as a redox catalyst have a higher discharge starting voltage than a lithium gas battery that includes carbon in the positive electrode without containing them in the positive electrode, and are supported on a carbon carrier. It has been found that a lithium gas battery including a redox catalyst produced by firing Fe phthalocyanine or Co phthalocyanine in the positive electrode has a higher discharge starting voltage. Further, as a result of earnest research, the present inventor has found that a lithium gas battery including a redox catalyst prepared by supporting Fe phthalocyanine added with sulfur on a carbon support and calcining the cathode has high Coulomb efficiency. did. By firing, it becomes possible to strengthen the bonding between the support and the metal phthalocyanine complex, and the frequency of the two-electron reduction reaction can be increased, so the central metal is a metal other than Fe or Co. Even if a metal phthalocyanine complex is used as a redox catalyst, it is considered possible to increase the discharge start voltage of a lithium gas battery.

  The present invention has been made based on such knowledge. An object of the present invention is to provide a lithium gas battery capable of increasing the discharge start voltage.

  The present invention will be described below with reference to the drawings. In addition, the form shown below which uses air as gas which can be oxidized / reduced is an illustration of this invention, and this invention is not limited to the form shown below.

  FIG. 1 is a conceptual diagram illustrating a lithium gas battery 10 of the present invention. As shown in FIG. 1, the lithium gas battery 10 includes a negative electrode 1, a positive electrode 2, and an electrolyte layer 3 disposed between the negative electrode 1 and the positive electrode 2. The negative electrode 1 is made of metallic lithium, and the positive electrode 2 contains a redox catalyst prepared by adding sulfur to Fe phthalocyanine and then carrying it on a carbon support and firing it. The electrolyte layer 3 includes a nonaqueous electrolytic solution having lithium ion conductivity and a porous separator that holds the nonaqueous electrolytic solution. The positive electrode 2 contains a redox catalyst prepared through a process of firing Fe-phthalocyanine added with sulfur (hereinafter referred to as “sulfur-added Fe phthalocyanine”) supported on a carbon support. Compared with the case where the calcined sulfur-added Fe phthalocyanine is not contained, the discharge start voltage of the lithium gas battery 10 can be increased. In FIG. 1, a negative electrode current collector for collecting current of the negative electrode 1, a negative electrode lead connected to the negative electrode current collector, a positive electrode current collector for collecting current of the positive electrode 2, and a positive electrode current collector. In addition, the description of the positive electrode lead and the exterior material that accommodates the negative electrode 1, the positive electrode 2, and the electrolyte layer 3 is omitted.

The oxidation-reduction catalyst contained in the positive electrode 2 is produced through a firing process. For this reason, it is possible to strongly bond the sulfur-added Fe phthalocyanine and the carbon carrier supporting the sulfur-added Fe phthalocyanine as compared with the case where the firing process is not performed. Since the conventional oxidation-reduction catalyst that has not undergone the firing process is not strongly bonded to the carbon support, it is considered that the carbon support component is the main component in the electron conduction of the electrode. The discharge start voltage of the carbon support is 2.7 V, and it is considered that the following reactions (formulas (1) to (4)) occur on the surface of the carbon support in the positive electrode under such a voltage.
O ₂ + e ⁻ → O ₂ ⁻ Formula (1)
O ₂ ⁻ + Li ⁺ → LiO ₂ formula (2)
O ₂ + 2e ⁻ → O ₂ ² —Formula (3)
O ₂ ²⁻ + 2Li ⁺ → Li ₂ O ₂ formula (4)
Formula (1) and Formula (2) are reactions in which lithium oxide is generated through radicals, and Formulas (3) and (4) are reactions in which lithium peroxide is generated through radicals.

On the other hand, as will be described later, the discharge start voltage of the calcined sulfur-added Fe phthalocyanine is less than 3 V, which is higher than the discharge start voltage of the carbon support. By baking, it becomes possible to strongly bond the sulfur-added Fe phthalocyanine and the carbon support, so that electrons can reach the sulfur-added Fe phthalocyanine, and the generation rate of the two-electron reduction reaction can be increased. Therefore, it is considered that the following reaction (formula (5)) occurs on the surface of the sulfur-added Fe phthalocyanine in the positive electrode 2 under a voltage of slightly less than 3V.
O ₂ + 2Li ⁺ + 2e ⁻ → Li ₂ O ₂ formula (5)
Formula (5) is a reaction in which lithium peroxide is generated without involving a radical. As described above, in the positive electrode 2, it is possible to cause a reaction that does not involve radicals, and thus it is possible to improve the durability of the positive electrode 2.

  Further, in the positive electrode 2 having the calcined sulfur-added Fe phthalocyanine, the molar ratio (N / C) of nitrogen and carbon constituting the calcined sulfur-added Fe phthalocyanine is 0.005 <N / C <0.013. Can be in the range. By making the value of N / C within this range, it becomes possible to increase the active sites (tricoordinate nitrogen) of the redox catalyst with which lithium ions react, so that molecular recognition, change, and migration of the redox catalyst The basic performance can be improved. Therefore, the performance of the lithium gas battery 10 can be improved by adopting such a configuration having the positive electrode 2.

  The negative electrode 1 is made of metallic lithium. Therefore, it is possible to occlude and release lithium ions. In the above description, the lithium gas battery 10 having the negative electrode 1 composed of metallic lithium is exemplified, but the negative electrode in the lithium gas battery of the present invention has a negative electrode active material capable of occluding and releasing lithium ions. The negative electrode may be in a form other than metallic lithium. Specific examples of the negative electrode active material capable of occluding and releasing lithium ions include metal lithium, lithium-containing alloys, lithium-containing metal oxides, and lithium-containing metal nitrides. . Examples of the alloy containing lithium include a lithium aluminum alloy, a lithium tin alloy, a lithium lead alloy, and a lithium silicon alloy. Moreover, as a metal oxide containing lithium, lithium titanium oxide etc. can be mentioned, for example. Examples of the metal nitride containing lithium include lithium cobalt nitride, lithium iron nitride, and lithium manganese nitride.

  Further, the negative electrode in the lithium gas battery of the present invention can include not only a form containing a negative electrode active material but also a form containing at least one of a conductive material and a binder in addition to the negative electrode active material. . For example, when the negative electrode active material has a foil shape, the negative electrode active material can be included. On the other hand, when a negative electrode active material is a powder form, it can be set as the form containing a negative electrode active material, an electroconductive material, and a binder, for example. When the conductive material is included in the negative electrode, the conductive material can withstand the environment when using the negative electrode (when using a lithium gas battery including the negative electrode) and has conductivity, in particular. It is not limited. Examples of such conductive materials include carbon materials such as carbon black and mesoporous carbon. From the viewpoint of suppressing a decrease in reaction field and a decrease in capacity, the content of the conductive material in the negative electrode is preferably 10% by mass or more. Moreover, when a binder is contained in the negative electrode, a binder such as polyvinylidene fluoride (PVDF) or polytetrafluoroethylene (PTFE) can be contained. Although content of the binder in a negative electrode is not specifically limited, For example, it is preferable to set it as 10 mass% or less, and it is more preferable to set it as 1 mass% or more and 5 mass% or less.

  Moreover, the negative electrode collector which collects the current of the negative electrode 1 can be formed of a known conductive material. Examples of the conductive material that can constitute the negative electrode current collector include copper, stainless steel, nickel, and carbon. Examples of the shape of the negative electrode current collector include a foil shape, a plate shape, and a mesh (grid) shape. In the present invention, the exterior material (battery case) (not shown) that accommodates the negative electrode 1, the positive electrode 2, and the electrolyte layer 3 may have the function of the negative electrode current collector.

  The positive electrode 2 contains a conductive material and a redox catalyst, and may further contain a binder as necessary. The conductive material used for the positive electrode 2 is not particularly limited as long as it can withstand the environment when using the positive electrode (when using a lithium gas battery including the positive electrode) and has conductivity. Absent. As such a conductive material, a carbon material, a perovskite type conductive material, a porous conductive polymer, a metal porous body, and the like can be exemplified. In particular, the carbon material may not have a porous structure, but it should have a porous structure with a large specific surface area from the viewpoint of providing a form capable of providing many reaction fields. Is preferred. Examples of the carbon material having a porous structure include mesoporous carbon, and examples of the carbon material having no porous structure include graphite, acetylene black, carbon nanotube, and carbon fiber. . Such a carbon material can be contained as a carrier for supporting a redox catalyst like the positive electrode 2. The content of the conductive material in the positive electrode 2 is, for example, 65% by mass or more and preferably 75% by mass or more from the viewpoint of reducing the reaction field and preventing the battery capacity from decreasing. Further, from the viewpoint of avoiding a situation where the catalyst content is relatively reduced and a sufficient catalyst function cannot be exhibited, the content of the conductive material in the positive electrode 2 is 99% by mass or less and 95% by mass or less. It is preferable.

  As described above, the positive electrode 2 contains the calcined sulfur-added Fe phthalocyanine in a form supported on a carbon support. By adopting a form containing calcined sulfur-added Fe phthalocyanine as a redox catalyst, the discharge starting voltage is increased, the durability of the positive electrode 2 is improved, and the molecular recognition and change of the redox catalyst It becomes possible to improve the performance of the lithium gas battery 10 by improving the basic performance of movement. In the description relating to the lithium gas battery 10, the positive electrode 2 in which the calcined sulfur-added Fe phthalocyanine is contained in a form supported on a carbon support is exemplified, but the redox contained in the positive electrode of the lithium gas battery of the present invention. The catalyst is not limited to this form. The redox catalyst contained in the positive electrode of the lithium gas battery according to the present invention may be any redox catalyst prepared by firing a metal phthalocyanine complex supported on a carrier. Examples of such a redox catalyst include a metal phthalocyanine complex prepared through a process of adding sulfur and baking, and a metal phthalocyanine complex prepared through a process of baking without adding sulfur. Examples of the metal phthalocyanine complex to be fired in the present invention include Fe phthalocyanine and Co phthalocyanine, as well as metal phthalocyanine complexes whose central metals are Mn, V, Cu, Mo, and Ni. However, it is preferable to use Fe phthalocyanine or Co phthalocyanine in the present invention because the valence is +2 and stable in the operating potential range of the lithium gas battery, and redox with valences of +2 and +3 is possible. . In the present invention, the content of the oxidation-reduction catalyst in the positive electrode is 1% by mass or more and preferably 5% by mass or more from the viewpoint of making it a form capable of exhibiting a sufficient catalytic function. Further, from the viewpoint of avoiding a situation where the content of the conductive material is relatively reduced to reduce the reaction field and the battery capacity is reduced, the content of the oxidation-reduction catalyst in the positive electrode is 30% by mass or less, It is preferable to set it as 20 mass% or less.

  When the binder is included in the positive electrode of the lithium gas battery of the present invention, the same binder as that of the negative electrode 1 can be used. Although content of the binder in a positive electrode is not specifically limited, For example, it is preferable to set it as 10 mass% or less, and it is more preferable to set it as 1 mass% or more and 5 mass% or less.

  The positive electrode current collector that collects current from the positive electrode 2 can be formed of a known conductive material. Examples of the conductive material that can constitute the positive electrode current collector include stainless steel, nickel, aluminum, iron, titanium, and carbon. Moreover, as a shape of a positive electrode electrical power collector, foil shape, plate shape, mesh (grid) shape etc. can be illustrated. Among these, in the present invention, since the current collection efficiency is excellent, the shape of the positive electrode current collector is preferably a mesh shape. In this case, a mesh-shaped positive electrode current collector can be disposed inside the positive electrode. Furthermore, the lithium gas battery of the present invention may have another positive electrode current collector (for example, a foil-shaped current collector) that collects charges collected by the mesh-shaped positive electrode current collector. Further, in the present invention, an exterior material (battery case) (not shown) that accommodates the negative electrode 1, the positive electrode 2, and the electrolyte layer 3 may have the function of a positive electrode current collector. The thickness of the positive electrode current collector can be, for example, from 10 μm to 1000 μm, and preferably from 20 μm to 400 μm.

The electrolyte layer 3 has a nonaqueous electrolytic solution having lithium ion conductivity and a porous separator that holds the nonaqueous electrolytic solution. The nonaqueous electrolytic solution having lithium ion conductivity contains, for example, a lithium salt and an organic solvent. Examples of the lithium salt include LiPF ₆ , LiBF ₄ , LiClO _4, LiAsF _{6 and} other inorganic lithium salts, LiCF ₃ SO ₃ , LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ , LiC An organic lithium salt such as (CF ₃ SO ₂ ) ₃ can be exemplified. Examples of the organic solvent include ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), butylene carbonate, γ-butyrolactone, sulfolane, acetonitrile, 1 , 2-dimethoxymethane, 1,3-dimethoxypropane, diethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, and mixtures thereof. Moreover, it is preferable that an organic solvent is a solvent with high oxygen solubility from a viewpoint of making it the form in which dissolved oxygen is used for reaction efficiently. The concentration of the lithium salt in the non-aqueous electrolyte is, for example, not less than 0.2 mol / L and not more than 3 mol / L. In the lithium gas battery of the present invention, a low-volatile liquid such as an ionic liquid can be used as a solvent for dissolving the lithium salt. Examples of the ionic liquid that can be used in the present invention include N-methyl-N-propylpiperidinium bis (trifluoromethanesulfonyl) amide (common name: PP13-TFSA), N-methyl-N-propylpyrrolidinium bis (Trifluoromethanesulfonyl) amide (common name; P13-TFSA) and the like can be exemplified. A nonaqueous electrolytic solution can be prepared by dissolving the lithium salt in such an ionic liquid.

  Examples of the porous separator contained in the electrolyte layer 3 include non-woven fabrics such as resin non-woven fabrics and glass fiber non-woven fabrics, in addition to porous membranes such as polyethylene and polypropylene.

  In addition, the lithium gas battery of the present invention has an exterior material (battery case) that houses a negative electrode, a positive electrode, an electrolyte layer, and the like. Examples of the shape of the battery case include a coin type, a flat plate type, a cylindrical type, and a laminate type. The battery case may be an open-air battery case or a sealed battery case. An open-air battery case is a battery case having a structure in which at least the positive electrode can sufficiently come into contact with the atmosphere. On the other hand, when the battery case is a sealed battery case, it is preferable that the sealed battery case is provided with an introduction pipe and a discharge pipe for a gas capable of oxidation / reduction (air in the lithium gas battery 10). In this case, the introduced / exhausted air preferably has a high oxygen concentration, and more preferably pure oxygen. In addition, it is preferable to increase the oxygen concentration during discharging and decrease the oxygen concentration during charging.

  In the above description related to the present invention, the form in which air is used as the gas capable of oxidation and reduction has been exemplified, but the lithium gas battery of the present invention is not limited to this form. Examples of the gas that can be oxidized and reduced include oxygen, nitrogen, carbon dioxide, hydrogen, and a gas obtained by mixing two or more of these, in addition to air.

1. Production of cell for performance evaluation <Production of positive electrode containing calcined Fe phthalocyanine>
Fe phthalocyanine and activated carbon (Super P, hereinafter referred to as “SP”) were dispersed in acetone to support Fe phthalocyanine on SP. Thereafter, Fe phthalocyanine supported on SP was taken out from acetone and baked in an Ar atmosphere at 800 ° C. for 2 hours. Then, a mixture of a fired Fe phthalocyanine supported on SP and a binder (PTFE) is mixed to form a pellet-like mixture, and dried to produce a positive electrode containing the fired Fe phthalocyanine. did. The mass ratio of SP, PTFE, and redox catalyst (Fe phthalocyanine) contained in the positive electrode was SP: PTFE: redox catalyst = 8: 1: 1. FIG. 2 shows the state before and after the firing of Fe phthalocyanine supported on SP. FIG. 2 is a photograph observed with a transmission electron microscope (FEI company Tecnai G2 F30S-Twin). The upper side of FIG. 2 is a photograph before firing, and the lower side is a photograph after firing. As shown in FIG. 2, carbon having a nanoshell structure and Fe particles having a diameter of 5 nm were generated by firing.

<Preparation of a positive electrode containing calcined Co phthalocyanine>
A positive electrode containing calcined Co phthalocyanine was produced in the same manner as in “Preparation of calcined positive electrode containing Fe phthalocyanine” except that Co phthalocyanine was used instead of Fe phthalocyanine. FIG. 3 shows the state before and after the firing of Co phthalocyanine supported on SP. FIG. 3 is a photograph observed with a transmission electron microscope (FEI company Tecnai G2 F30S-Twin). The upper side of FIG. 3 is a photograph before firing, and the lower side is a photograph after firing. As shown in FIG. 3, carbon having a nanoshell structure and Co particles having a diameter of 20 nm were generated by firing.

<Preparation of a positive electrode containing calcined sulfur-added Fe phthalocyanine>
An amount of sulfur in which the molar ratio of sulfur to Fe phthalocyanine is sulfur: Fe phthalocyanine = 2.7: 1 is mixed with sulfur (or thiourea) and an acetone solution, and then dispersed and fired to obtain Fe phthalocyanine. Added to. A positive electrode containing calcined sulfur-added Fe phthalocyanine was produced in the same manner as in “Preparation of calcined Fe phthalocyanine-containing positive electrode” except that the calcining temperature was 550 ° C. and the calcining time was 2 hours. . The molar ratio of sulfur to Fe phthalocyanine (hereinafter sometimes referred to as “S / Fe”) was set to sulfur: Fe phthalocyanine = 2.7: 1. This is because the oxidation-reduction potential sometimes increases.

<Preparation of Sintered Positive Electrode Containing Sulfur-added Co Phthalocyanine>
Except for using Co phthalocyanine instead of Fe phthalocyanine, a positive electrode containing Co phthalocyanine baked by adding sulfur in the same manner as in “Preparation of baked positive electrode containing sulfur-added Fe phthalocyanine” above. Produced.

<Preparation of Sintered Positive Electrode Containing Sulfur-Added Phthalocyanine>
In place of Fe phthalocyanine, except for using phthalocyanine in which the central hydrogen is not substituted by Fe, sulfur addition by calcining is performed in the same manner as in “Preparation of cathode containing calcined sulfur-added Fe phthalocyanine”. A positive electrode containing phthalocyanine was prepared.

<Preparation of positive electrode containing unfired Fe phthalocyanine>
A positive electrode containing unfired Fe phthalocyanine was produced in the same manner as in “Preparation of fired positive electrode containing Fe phthalocyanine” except that it was not fired.

<Preparation of positive electrode containing unfired Co phthalocyanine>
A positive electrode containing unfired Co phthalocyanine was produced in the same manner as in “Preparation of fired positive electrode containing Co phthalocyanine” except that it was not fired.

<Preparation of positive electrode containing unfired sulfur-added Fe phthalocyanine>
A positive electrode containing an unfired sulfur-added Fe phthalocyanine was produced in the same manner as in the above-mentioned “Preparation of a fired positive electrode containing sulfur-added Fe phthalocyanine” except that it was not fired.

<Preparation of positive electrode containing unfired sulfur-added Co phthalocyanine>
A positive electrode containing an unfired sulfur-added Co phthalocyanine was produced in the same manner as in “Preparation of a fired sulfur-added Co phthalocyanine-containing positive electrode” except that it was not fired.

<Preparation of positive electrode containing unsintered sulfur-added phthalocyanine>
A positive electrode containing an unfired sulfur-added phthalocyanine was produced in the same manner as in “Preparation of a fired positive electrode containing sulfur-added phthalocyanine” except that it was not fired.

<Preparation of positive electrode containing no phthalocyanine complex>
SP and a binder (PTFE) were mixed to produce a pellet-like mixture, and then dried to produce a positive electrode containing no phthalocyanine complex. The mass ratio of SP and PTFE contained in the positive electrode was SP: PTFE = 9: 1.

A performance evaluation cell comprising any positive electrode produced by the above method and the following components was produced. A cross-sectional view of the produced performance evaluation cell 40 is shown in FIG.
Negative electrode: metallic lithium (Honjo Metal Co., Ltd., thickness 200 μm, diameter 15 mm)
Electrolyte solution: PP13-TFSA solvent with 0.32 mol / kg Li-TFSA dissolved Separator: Polypropylene nonwoven fabric (product name “Pervio”, manufactured by Sumitomo Chemical Co., Ltd.)
Cell: F-type cell (made by Hokuto Denko Co., Ltd.)
Container: Glass desiccator with gas replacement cock (volume: 500 mL)
Gas: oxygen, argon

  As shown in FIG. 4, the cell 40 includes a negative electrode 41, a positive electrode 42, an electrolyte layer 43 disposed therebetween, a conductor 44 connected to the negative electrode 41, and an anode line 45 connected to the conductor 44. A hollow conductor 46 connected to the positive electrode 42, a cathode line 47 connected to the conductor 46, a member 48 disposed between the electrolyte layer 43 and the conductor 44, and the positive electrode 42 and the electrolyte layer 43. A member 49 disposed around the member 49, a member 50 disposed on the member 49, and a container 51 for housing them. The inside of the container 51 is filled with oxygen or argon, and this oxygen or argon can reach the positive electrode 42 through the inside of the conductor 46. The negative electrode 41 is metallic lithium, and the positive electrode 42 is any positive electrode produced by the above method. The electrolyte layer 43 is a layer configured by holding the electrolytic solution on the separator, and the conductor 44 and the conductor 46 are made of stainless steel. The member 48 is made of nickel, the members 49 and 50 are made of resin, and the container 51 is made of glass.

2. Charge / Discharge Performance Evaluation The charge / discharge performance of the produced performance evaluation battery cell was evaluated under the following conditions. The discharge test results are shown in FIGS. 5 to 8, and the charge test results are shown in FIGS. 9 to 12, respectively. 5 to 8, the vertical axis represents voltage [V], the horizontal axis represents discharge capacity (specific capacity per electrode weight) [mAh / g], and the vertical axes in FIGS. 9 to 12 represent voltage [V] and horizontal The axis is the charge capacity (specific capacity per electrode weight) [mAh / g]. Moreover, the result of the discharge start voltage obtained from FIGS. 5-8 is shown in FIG. The horizontal axis of FIG. 13 is the discharge start voltage [V].
Charge / Discharge Tester: Nagano Corporation Charge / Discharge Tester (BTS2004H)
Current density: 0.05 mA / cm ²
End-of-discharge voltage: 2.0V
End-of-charge voltage: 3.8V
Measurement temperature: 60 ° C

FIG. 5 is a diagram showing a discharge test result (result of discharge in the first cycle) of a battery cell containing an unfired phthalocyanine complex and a battery cell containing no phthalocyanine complex. FIG. 5 shows the result of discharging while supplying argon to the positive electrode containing unfired Co phthalocyanine (Ar—Co), and discharging while supplying argon to the positive electrode containing unfired Fe phthalocyanine. As a result of the case (Ar-Fe), as a result of discharging while supplying oxygen to the positive electrode containing unfired Co phthalocyanine (O ₂ -Co), oxygen was added to the positive electrode containing unfired Fe phthalocyanine. The results (O ₂ —Fe) in the case of discharging while supplying and the results (O ₂ —SP) in the case of discharging while supplying oxygen to the positive electrode not containing the phthalocyanine complex are shown.

As shown in FIG. 5, the battery (O ₂ -Co) discharged while supplying oxygen to the positive electrode containing unfired Co phthalocyanine was discharged while supplying oxygen to the positive electrode not containing phthalocyanine complex. The specific capacity was larger than that of the battery (O ₂ -SP). Further, a battery (O ₂ —Fe) discharged while supplying oxygen to a non-fired positive electrode containing Fe phthalocyanine (O ₂ —Fe) was discharged (O ₂ −) while supplying oxygen to a positive electrode not containing phthalocyanine complex. The specific capacity was smaller than SP). In addition, the battery (Ar—Co, Ar—Fe) discharged while supplying argon to the positive electrode has a smaller specific capacity than the battery (O ₂ —Co, O ₂ —Fe) discharged while supplying oxygen to the positive electrode. The specific capacities of the batteries (Ar—Co, Ar—Fe) discharged while supplying argon to the positive electrode were similar.

FIG. 6 is a diagram showing a discharge test result (result of discharge in the first cycle) of a battery cell containing a fired phthalocyanine complex and a battery cell containing no phthalocyanine complex. FIG. 6 shows the result of discharging while supplying argon to the positive electrode containing calcined Co phthalocyanine (Ar-baked Co), and the case of discharging while supplying argon to the positive electrode containing calcined Fe phthalocyanine. Results (Ar-baked Fe), results of discharging while supplying oxygen to the fired positive electrode containing Co phthalocyanine (O ₂ -fired Co), supplying oxygen to the fired positive electrode containing Fe phthalocyanine The results (O ₂ -fired Fe) when discharged while discharging and the results (O ₂ -SP) when discharged while supplying oxygen to the positive electrode not containing a phthalocyanine complex are shown.

As shown in FIG. 6, the battery discharged while supplying oxygen to the fired positive electrode containing Fe phthalocyanine (O ₂ -fired Fe) was discharged while supplying oxygen to the positive electrode not containing phthalocyanine complex. The specific capacity was larger than that of the battery (O ₂ -SP). In addition, a battery (O ₂ -baked Co) discharged while supplying oxygen to the fired positive electrode containing Co phthalocyanine (O ₂ -fired Co) was discharged while supplying oxygen to the positive electrode not containing phthalocyanine complex (O _2- The specific capacity was smaller than SP). The battery (Ar- baked Co, Ar- baked Fe) of discharging while supplying argon to the positive electrode, the battery was discharged while supplying oxygen to the cathode _{(O 2} - baked Co, _{O 2} - baked Fe) than The specific capacities of the batteries (Ar-fired Co and Ar-fired Fe) discharged with the specific capacity being small and supplying argon to the positive electrode were comparable.

As shown in FIG. 5 and FIG. 6, the battery (O ₂ -fired Fe) discharged while supplying oxygen to the fired positive electrode containing Fe phthalocyanine had oxygen added to the positive electrode containing unfired Fe phthalocyanine. The specific capacity was larger than the battery (O ₂ —Fe) discharged while being supplied. This is presumably because the reaction of the above formula (5) occurs on the surface of Fe phthalocyanine as a result of strong bonding of Fe phthalocyanine and SP by firing. On the other hand, as shown in FIGS. 5 and 6, the battery (O ₂ -fired Co) discharged while supplying oxygen to the fired positive electrode containing Co phthalocyanine contains unfired Co phthalocyanine. The specific capacity was smaller than that of the battery (O ₂ —Co) discharged while supplying oxygen to the positive electrode. This is considered to be because Co phthalocyanine and SP were strongly joined by firing, but Co aggregated by firing as shown in FIG.

  FIG. 7 is a diagram showing a discharge test result (result of discharge in the first cycle) of a battery cell containing an unfired phthalocyanine complex, and FIG. 8 is a discharge of a battery cell containing a fired phthalocyanine complex. It is a figure which shows a test result (result of discharge of the 1st cycle). Specifically, FIG. 7A is a diagram showing a result (sulfur-added phthalo) when discharging while supplying oxygen to a positive electrode containing unfired sulfur-added phthalocyanine, and FIG. These are figures which show the result (sulfur addition Fe phthalo) at the time of discharging, supplying oxygen to the positive electrode containing the non-baking sulfur addition Fe phthalocyanine, FIG.7 (c) is the sulfur addition which is not baking. It is a figure which shows the result (sulfur addition Co phthalo) at the time of discharging, supplying oxygen to the positive electrode containing Co phthalocyanine. FIG. 8A is a diagram showing a result (sulfur-added calcined phthalo) when discharging while supplying oxygen to the calcined positive electrode containing sulfur-added phthalocyanine, and FIG. It is a figure which shows the result (sulfur addition calcination Fe phthalo) at the time of discharging, supplying oxygen to the positive electrode containing the made sulfur addition Fe phthalocyanine, FIG.8 (c) contains the baked sulfur addition Co phthalocyanine It is a figure which shows the result (sulfur addition baking Co phthalo) at the time of discharging, supplying oxygen to the positive electrode which does.

  As shown in FIGS. 7 and 8, the specific capacity of the battery (sulfur-added Co phthalo) discharged while supplying oxygen to the positive electrode containing unfired sulfur-added Co phthalocyanine is the largest. Batteries discharged while supplying oxygen to the positive electrode containing added Fe phthalocyanine (sulfur-added calcined Fe phthalo), Batteries discharged while supplying oxygen to the positive electrode containing calcined sulfur-added Co phthalocyanine (sulfur-added calcined Co phthalo) ), A battery discharged while supplying oxygen to the calcined positive electrode containing sulfur-added phthalocyanine (sulfur-added calcined phthalo), a battery discharged while supplying oxygen to an unfired positive electrode containing sulfur-added Fe phthalocyanine ( Sulfur-added Fe phthalo), do not supply oxygen to the positive electrode containing unfired sulfur-added phthalocyanine In the order of al discharged battery (sulfur added phthaloyl), the specific capacity is reduced.

FIG. 9 is a diagram showing a charge test result (result of charge in the first cycle) of a battery cell containing an unfired phthalocyanine complex. FIG. 9 shows the result of charging while supplying argon to the positive electrode containing unfired Co phthalocyanine (Ar—Co), and charging while supplying argon to the positive electrode containing unfired Fe phthalocyanine. result (Ar-Fe) of the case, the result in the case where the oxygen in the positive electrode containing Co phthalocyanine uncalcined charged while supplying (O 2 _-Co), and, in the positive electrode containing Fe phthalocyanine uncalcined The result (O ₂ —Fe) in the case of charging while supplying oxygen is shown.

As shown in FIG. 9, the battery (O ₂ —Co) charged while supplying oxygen to the positive electrode containing unfired Co phthalocyanine supplied oxygen to the positive electrode containing unfired Fe phthalocyanine. The specific capacity was larger than that of the charged battery (O ₂ —Fe). In addition, the battery (Ar—Co, Ar—Fe) charged while supplying argon to the positive electrode has a smaller specific capacity than the battery (O ₂ —Co, O ₂ —Fe) charged while supplying oxygen to the positive electrode. A battery (Ar-Fe) charged while supplying argon to a positive electrode containing unfired Fe phthalocyanine (Ar-Fe) was charged while supplying argon to a positive electrode containing unfired Co phthalocyanine (Ar-Co). ) Was less than the specific capacity.

FIG. 10 is a diagram showing a charge test result (result of charge in the first cycle) of a battery cell containing a fired phthalocyanine complex. FIG. 10 shows the result of charging while supplying argon to the positive electrode containing calcined Co phthalocyanine (Ar-baked Co), and charging when supplying argon to the positive electrode containing calcined Fe phthalocyanine Results (Ar-baked Fe), results of charging while supplying oxygen to the fired positive electrode containing Co phthalocyanine (O ₂ -fired Co), and oxygen in the fired positive electrode containing Fe phthalocyanine The results (O ₂ -fired Fe) when charged while supplying s are shown.

As shown in FIG. 10, the battery charged with supplying oxygen to the fired positive electrode containing Fe phthalocyanine (O ₂ -fired Fe) is charged while supplying oxygen to the fired positive electrode containing Co phthalocyanine. The specific capacity was larger than that of the obtained battery (O ₂ -fired Co). The battery (Ar- baked Co, Ar- baked Fe) was charged while supplying argon to the positive electrode, the battery was charged while supplying oxygen to the cathode _{(O 2} - baked Co, _{O 2} - baked Fe) than The specific capacities of the batteries (Ar-fired Co, Ar-fired Fe) charged with argon being supplied to the positive electrode were almost the same.

As shown in FIGS. 9 and 10, the battery charged with supplying oxygen to the fired positive electrode containing Fe phthalocyanine (O ₂ -fired Fe) was charged with oxygen to the non-fired positive electrode containing Fe phthalocyanine. The specific capacity was larger than that of the battery (O ₂ —Fe) charged while being supplied. This is considered to be because the reaction easily occurred on the surface of Fe phthalocyanine as a result of strong bonding of Fe phthalocyanine and SP by firing. On the other hand, as shown in FIGS. 9 and 10, the battery (O ₂ -baked Co) charged while supplying oxygen to the fired positive electrode containing Co phthalocyanine contains unfired Co phthalocyanine. The specific capacity was smaller than that of the battery (O ₂ —Co) charged while supplying oxygen to the positive electrode. This is considered to be because Co phthalocyanine and SP were strongly joined by firing, but Co aggregated by firing as shown in FIG.

  FIG. 11 is a diagram illustrating a charge test result (result of discharge in the first cycle) of a battery cell containing an unfired phthalocyanine complex, and FIG. 12 is a charge of a battery cell containing a fired phthalocyanine complex. It is a figure which shows a test result (result of charge of the 1st cycle). Specifically, FIG. 11 (a) is a diagram showing a result (sulfur-added phthalo) when charging while supplying oxygen to a positive electrode containing unfired sulfur-added phthalocyanine, and FIG. 11 (b). These are figures which show the result (sulfur addition Fe phthalo) at the time of charging, supplying oxygen to the positive electrode containing the sulfur addition Fe phthalocyanine which is not baked, FIG.11 (c) is the sulfur addition which is not baked It is a figure which shows the result at the time of charging, supplying oxygen to the positive electrode containing Co phthalocyanine (sulfur addition Co phthalo). FIG. 12 (a) is a diagram showing a result (sulfur-added calcined phthalo) when charging while supplying oxygen to the calcined positive electrode containing sulfur-added phthalocyanine, and FIG. It is a figure which shows the result (sulfur addition baking Fe phthalo) at the time of charging, supplying oxygen to the positive electrode containing the sulfur addition Fe phthalocyanine made, FIG.12 (c) contains the baking sulfur addition Co phthalocyanine containing It is a figure which shows the result at the time of charging, supplying oxygen to the positive electrode which carries out (sulfur addition baking Co phthalo).

  As shown in FIGS. 11 and 12, the specific capacity of the battery (sulfur-added Co phthalo) charged while supplying oxygen to the positive electrode containing unfired sulfur-added Co phthalocyanine is largest. Batteries charged while supplying oxygen to the positive electrode containing added Fe phthalocyanine (sulfur-added calcined Fe phthalo), Batteries charged while supplying oxygen to the positive electrode containing calcined sulfur-added Co phthalocyanine (sulfur-added calcined Co phthalo) ), A battery charged while supplying oxygen to an unfired positive electrode containing sulfur-added Fe phthalocyanine (sulfur-added Fe phthalo), a battery charged while supplying oxygen to an unfired positive electrode containing sulfur-added phthalocyanine (Sulfur-added phthalo), do not supply oxygen to the calcined positive electrode containing sulfur-added phthalocyanine In the order of et charged battery (sulfur additive firing phthaloyl), the specific capacity is reduced.

  FIG. 13 is a table summarizing the results of the discharge start voltage obtained from FIGS. As shown in FIG. 13, the battery with the positive electrode containing unfired sulfur-added phthalocyanine and the battery with the positive electrode containing fired sulfur-added phthalocyanine were equipped with a positive electrode containing no phthalocyanine complex. The battery (corresponding to “SP” in FIG. 13; the same applies hereinafter) and the discharge start voltage were similar. In contrast, a battery with a positive electrode containing Co phthalocyanine, a battery with a positive electrode containing Fe phthalocyanine, a battery with a positive electrode containing sulfur-added Co phthalocyanine, and a positive electrode containing sulfur-added Fe phthalocyanine The provided battery had a higher discharge starting voltage than the battery provided with the positive electrode containing no phthalocyanine complex, and the initial coulomb efficiency was higher than that of the battery provided with the positive electrode containing no phthalocyanine complex. And the battery with the positive electrode containing the fired Co phthalocyanine has a higher discharge starting voltage than the battery with the positive electrode containing the unfired Co phthalocyanine, and the positive electrode containing the fired Fe phthalocyanine. The battery had a higher discharge initiation voltage than the battery with the positive electrode containing unfired Fe phthalocyanine. Similarly, a battery with a positive electrode containing calcined sulfur-added Co phthalocyanine has a higher discharge starting voltage than a battery with a positive electrode containing unfired sulfur-added Co phthalocyanine, and the calcined sulfur-added Fe The battery with the positive electrode containing phthalocyanine had a higher discharge initiation voltage than the battery with the positive electrode containing unfired sulfur-added Fe phthalocyanine. From the above, it was possible to increase the discharge start voltage by making the positive electrode contain a redox catalyst prepared by firing a metal phthalocyanine complex supported on a carrier.

  Table 1 summarizes the results of the charge / discharge test obtained from FIGS. The initial coulomb efficiency shown in Table 1 was calculated by initial coulomb efficiency = (charge capacity at the first cycle / discharge capacity at the first cycle) × 100.

  From Table 1, when Co phthalocyanine and Fe phthalocyanine were compared, the charge / discharge capacity of Co phthalocyanine was larger than the charge / discharge capacity of Fe phthalocyanine. On the other hand, when the calcined Co phthalocyanine was compared with the calcined Fe phthalocyanine, the charge / discharge capacity of the calcined Fe phthalocyanine was larger than the charge / discharge capacity of the calcined Co phthalocyanine. Moreover, the charge / discharge capacity of the fired Fe phthalocyanine was larger than the charge / discharge capacity of SP as a comparative material. On the other hand, from Table 1, when sulfur is added to the phthalocyanine complex, comparing the sulfur-added phthalo, sulfur-added Co phthalo and sulfur-added Fe phthalo, the charge / discharge capacity is the largest for the sulfur-added Co phthalo and the sulfur-added phthalo is the most It was small. On the other hand, when comparing the sulfur-added calcined phthalo, the sulfur-added calcined Co phthalo and the sulfur-added calcined Fe phthalo, the charge / discharge capacity was the largest for the sulfur-added calcined Fe phthalo and the sulfur-added calcined phthalo was the smallest. Also, from Table 1, in this result, the initial Coulomb efficiency of the battery including the positive electrode containing unfired Fe phthalocyanine was the highest. And the Co phthalocyanine, calcined Co phthalocyanine, Fe phthalocyanine, calcined Fe phthalocyanine, sulfur-added phthalo, sulfur-added Co phthalo, sulfur-added calcined Co phthalo, and sulfur-added calcined Fe phthalo listed in Table 1 The initial coulomb efficiency was larger than the initial coulomb efficiency of SP as a comparative material.

  Moreover, as shown in Table 1, the coulombic efficiency of the battery including the fired positive electrode containing Fe phthalocyanine was 49.5%, whereas the battery including the fired sulfur-added Fe phthalocyanine was provided. The coulombic efficiency of the battery was 66.9%. From Table 1, when the calcined Co phthalocyanine and the calcined Fe phthalocyanine are compared, it is preferable in the present invention to use calcined Fe phthalocyanine having a large charge / discharge capacity. Also, from Table 1, comparing calcined Fe phthalocyanine and calcined sulfur-added Fe phthalocyanine, in the present invention, it is preferable to use calcined sulfur-added Fe phthalocyanine having high Coulomb efficiency.

3. Measurement of nitrogen and carbon molar ratio N / C SP, Fe phthalocyanine, Co phthalocyanine, calcined Fe phthalocyanine, calcined Co phthalocyanine, calcined sulfur-added Fe phthalocyanine, and calcined sulfur-added Co phthalocyanine The molar ratio N / C of nitrogen and carbon to be measured was measured using an X-ray photoelectron spectrometer (PHI-5700, manufactured by ULVAC-PHI Co., Ltd.). The conditions of the X-ray photoelectron spectrometer were as follows.
X-ray source: AlKα monochrome, φ800μm, output 350W
Neutralizing gun: used

  Relationship between molar ratio N / C measured using an X-ray photoelectron spectrometer and discharge capacity, and 0 ≦ N / C ≦ 0.005, 0.005 <N / C <0.013, 0.013 ≦ FIG. 14 shows the arrangement of carbon atoms and nitrogen atoms at each time of N / C. Further, the relationship between the molar ratio N / C measured using an X-ray photoelectron spectrometer and the charge capacity, and 0 ≦ N / C ≦ 0.005, 0.005 <N / C <0.013, 0. FIG. 15 shows the arrangement of carbon atoms and nitrogen atoms at each time of 013 ≦ N / C. 14 and 15, the Fe phthalocyanine is “Fe phthalo”, the Co phthalocyanine is “Co phthalo”, the fired Fe phthalocyanine is “fired Fe phthalo”, and the fired Co phthalocyanine is “fired Co phthalo”. The sulfur-added Fe phthalocyanine was described as “sulfur-added calcined Fe phthalo”, and the calcined sulfur-added Co phthalocyanine was described as “sulfur-added calcined Co phthalo”. A curve indicated by a dotted line in FIG. 14 is an estimated curve having a molar ratio N / C as an input variable and a discharge capacity as an output variable. A curve indicated by a dotted line in FIG. 15 indicates that the molar ratio N / C is an input variable. It is an estimation curve using the charging capacity as an output variable.

  As shown in FIGS. 14 and 15, the calcined Fe phthalocyanine and the calcined Co phthalocyanine, and the calcined sulfur-added Fe phthalocyanine and the calcined sulfur-added Co phthalocyanine both have a molar ratio N / C. It belonged to the range of 0.005 <N / C <0.013. That is, it was possible to increase the discharge start voltage of a lithium gas battery by using a fired metal phthalocyanine complex that satisfies 0.005 <N / C <0.013.

  The lithium gas battery of the present invention can be used for electric vehicles and hybrid vehicles.

DESCRIPTION OF SYMBOLS 1 ... Negative electrode 2 ... Positive electrode 3 ... Electrolyte layer 10 ... Lithium gas battery 40 ... Cell 41 ... Negative electrode 42 ... Positive electrode 43 ... Electrolyte layer 44, 46 ... Conductor 45 ... Anode line 47 ... Cathode line 48, 49, 50 ... Member 51 ... container

Claims (4)

A negative electrode having a negative electrode active material capable of occluding and releasing lithium ions, a positive electrode using a gas capable of redox reduction as a positive electrode active material, and a non-aqueous ion conductor disposed between the negative electrode and the positive electrode ,
A lithium gas battery characterized in that the positive electrode contains a redox catalyst produced by firing a metal phthalocyanine complex supported on a carrier. The lithium gas battery according to claim 1, wherein a central metal of the metal phthalocyanine complex is Fe or Co. 3. The lithium gas battery according to claim 2, wherein a central metal of the metal phthalocyanine complex is Fe, and sulfur is added to the metal phthalocyanine complex. 4. The molar ratio N / C of nitrogen and carbon constituting the calcined metal phthalocyanine complex is 0.005 <N / C <0.013. 5. The lithium gas battery according to 1.