JP2020158835A - Metal halide foil, and all-solid battery and nonaqueous lithium ion battery including the same - Google Patents

Abstract

To provide a metal halide foil that prevents ununiform film deposition, and ununiform electrochemical reaction from film peeling or rupture due to the stress caused by a volumetric change of charging/discharging, and can improve cycle characteristics.SOLUTION: A metal halide foil has a surface modified with halogen element.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a lithium ion secondary battery.

Lithium-ion secondary batteries are lighter and have higher capacity than nickel-cadmium batteries, nickel-metal hydride batteries, and the like, and are therefore widely used as power sources for portable electronic devices. It is also a promising candidate for power sources installed in hybrid vehicles and electric vehicles. With the recent miniaturization and higher functionality of portable electronic devices, it is expected that the lithium ion secondary batteries used as power sources will have a longer life and a higher capacity.

Conventionally, a lithium ion secondary battery has a positive electrode and a negative electrode coated with a positive electrode active material or a negative electrode active material that stores and releases lithium ions on both sides of a sheet-shaped current collector such as aluminum or copper. A separator is sandwiched between the positive electrode and the negative electrode and wound a plurality of times to form a wound body, which is sealed together with an electrolytic solution in an exterior body having a cylindrical, square, or coin shape.

In addition to lithium-ion secondary batteries, research and development of all-solid-state batteries that do not use an electrolytic solution are being actively conducted because of their high safety.

All-solid-state batteries are classified into two types: thin film type and bulk type. The thin film type is manufactured by thin film technology such as PVD method and sol-gel method, and the bulk type is manufactured by dust molding of electrode active material and sulfide-based solid electrolyte, and by sintering when oxide solid electrolyte is used. Will be done.

Both lithium-ion secondary batteries and all-solid-state batteries have been desired to have higher capacity and higher energy density.

Therefore, from the viewpoint of obtaining a battery having a higher energy density and a larger electromotive force than graphite, which is a conventional negative electrode material, studies have been conducted on using metallic lithium as the negative electrode.

However, when metallic lithium is used, there is a problem that dendritic dendrites grow when charging and discharging are repeated, the metallic lithium contained therein is deactivated, and the cycle characteristics are low.
In addition, when metallic lithium is used for the all-solid-state battery, a reaction occurs with the solid electrolyte that comes into contact with the battery, an interface in which lithium ions do not easily move is formed, resulting in a non-uniform electrochemical reaction, resulting in cycle characteristics. There was a problem of low.

In view of such problems, Patent Documents 1, 2 and 3 propose to form a film on the surface of metallic lithium.

Japanese Unexamined Patent Publication No. 11-288706 Japanese Unexamined Patent Publication No. 7-302617 JP-A-53-88927

In Patent Document 1, (100) a uniform dissolution-precipitation reaction can be carried out by forming a film of a substance having a rock salt type crystal structure on the surface of a metallic lithium sheet in which the crystal planes are preferentially oriented, and metallic lithium. It has been proposed that the precipitation of dendrites can be suppressed and the cycle characteristics can be improved. It is described that the coating formed on the surface of the metallic lithium sheet is preferably a solid solution of LiF and at least one selected from LiCl, LiBr, and LiI, and (100) the metallic lithium sheet in which the crystal plane is preferentially oriented is , It is said that a commercially available lithium foil was repeatedly rolled with a steel jig.
However, the surface of a commercially available lithium foil is stabilized by oxidation, carbonation, hydroxylation, and nitriding for safety, and even if it is repeatedly rolled and oriented, it remains as a different phase. For this reason, it becomes difficult to form the desired uniform film, a sufficient dendrite precipitation suppressing effect cannot be obtained, and the cycle characteristics cannot be improved.

Patent Document 2 proposes a method of forming a lithium fluoride coating on the surface of metallic lithium by reacting with an electrolytic solution. However, when the lithium fluoride film is formed, the side reaction film is also formed, and it is difficult to form a uniform lithium fluoride film. In the case of a non-uniform coating, the ion conduction path becomes non-uniform, and the electrochemical reaction also occurs non-uniformly, so that the cycle characteristics cannot be improved.

Patent Document 3 proposes a method of forming a lithium iodide film on the surface of the negative electrode lithium by immersing the metallic lithium formed on the negative electrode in petroleum ether in which iodine is dissolved for 2 to 5 minutes.
However, although dehydration is carried out with metallic sodium to dehydrate petroleum ether, this also remains as an impurity. In addition, the surface of a commercially available lithium foil is stabilized by oxidation, carbonation, hydroxylation, and nitridation for safety, which makes it difficult to form the desired uniform film, which is sufficient. The effect of suppressing dendrite precipitation could not be obtained, and the cycle characteristics could not be improved.

Further, in any case, since the volume changes when charging and discharging are repeated, the stress causes peeling and tearing of the formed film, which reduces the dendrite suppression effect and causes a non-uniform electrochemical reaction. Therefore, the cycle characteristics could not be improved.

The present disclosure has been made in view of the above-mentioned problems of the prior art, and an object of the present disclosure is to provide a halogenated metal foil having high cycle characteristics.

The halogenated metal foil according to the present disclosure preferably has a modified layer in which the surface of a metal containing Li, Na and K metals is modified with a halogen element, and a metal portion.

According to such a configuration, Li, Na, K, and a metal are melted to form a metal foil, and the surface thereof is modified with a halogen element to form a metal foil having a modified layer, whereby the metal foil is firmly bonded to the metal portion. It becomes possible to uniformly form the modified layer. As a result, the destruction of the modified layer due to the volume change when charging and discharging are repeated is reduced, a uniform electrochemical reaction occurs, dendrite precipitation is suppressed, and the cycle characteristics can be improved.

The halogenated metal leaf according to the present disclosure preferably includes the modified layer in which the distribution amount of the halogen elements is present in a gradation pattern.

According to this configuration, the amount of halogen elements distributed in the modified layer changes in a gradation manner, so that the modified layer firmly bonded to the metal portion can be made flexible. This makes it possible to relieve stress due to volume changes when charging and discharging are repeated, further reducing the destruction of the modified layer, and enabling a uniform electrochemical reaction in which dendrite precipitation is suppressed. .. This makes it possible to further improve the cycle characteristics.

In the halogenated metal foil according to the present disclosure, it is preferable that the distribution amount of the halogen element decreases toward the metal portion in the gradation.

According to this configuration, by forming the distribution amount of the halogen element into a gradation shape that decreases toward the metal portion, it is possible to give more flexibility to the modified layer that is firmly bonded to the metal portion. .. This makes it possible to relieve stress due to volume changes when charging and discharging are repeated, further reducing the destruction of the modified layer, and enabling a uniform electrochemical reaction in which dendrite precipitation is suppressed. .. This makes it possible to further improve the cycle characteristics.

In the metal halide foil according to the present disclosure, it is preferable that the modified layer contains at least one selected from the group consisting of iodide, fluoride, chloride and bromide.

According to such a configuration, Li, Na and K metals are melted and formed into a metal foil, and the surface thereof is modified into iodide, fluoride, chloride and bromide, whereby the modification is firmly bonded to the metal portion. The layer can be provided with an iodide conduction function, allowing for a more uniform electrochemical reaction. This makes it possible to further improve the cycle characteristics.

The halogenated metal foil according to the present disclosure preferably has a thickness of 20 μm to 1000 μm.

According to this configuration, the metal foil having a thickness of 20 μm to 1000 μm improves the handleability when manufacturing the electrode. This makes it possible to fabricate a homogeneous electrode, reduce the destruction of the modified layer due to local volume changes when charging and discharging are repeated, and enable a uniform electrochemical reaction in which dendrite precipitation is suppressed. Become. This makes it possible to further improve the cycle characteristics.

In the metal halide foil according to the present disclosure, the thickness of the modified layer is preferably larger than 10 nm and smaller than 5 μm.

According to such a configuration, when the thickness of the modified layer is larger than 10 nm and smaller than 5 μm, it becomes possible to produce a homogeneous electrode having low internal resistance, and a uniform electrochemical reaction becomes possible. As a result, the destruction of the modified layer due to the volume change when the charging / discharging is repeated is further reduced, and the dendrite precipitation can be further suppressed. This makes it possible to further improve the cycle characteristics.

In the all-solid-state battery according to the present disclosure, it is preferable to use at least one of the above-mentioned metal halide foils for the positive electrode or the negative electrode.

According to such a configuration, the destruction of the modified layer due to the volume change when the charging / discharging is repeated is reduced, and a uniform electrochemical reaction in which the precipitation of dendrite is suppressed becomes possible. This makes it possible to improve the cycle characteristics.

In the lithium ion battery according to the present disclosure, it is preferable to use at least one of the above-mentioned metal halide foils for the positive electrode or the negative electrode.

According to such a configuration, the destruction of the modified layer due to the volume change when the charging / discharging is repeated is reduced, and a uniform electrochemical reaction in which the precipitation of dendrite is suppressed becomes possible. This makes it possible to improve the cycle characteristics.

According to the present disclosure, the surface of the Li, Na, and K metal particles is formed into a metal foil having a modified layer modified with a halogen element, so that the modified layer is destroyed by a volume change when charging and discharging are repeated. Is reduced, a uniform electrochemical reaction occurs, and precipitation of dendrites is suppressed, so that the cycle characteristics can be improved.

It is a schematic cross-sectional view of the halogenated metal foil of this embodiment. It is a schematic cross-sectional view which shows an example of the lithium ion secondary battery using the halogenated metal foil of this embodiment. It is a schematic cross-sectional view which shows an example of the all-solid-state battery using the halogenated metal foil of this embodiment.

Hereinafter, preferred embodiments of the present disclosure will be described with respect to the present disclosure. The present disclosure is not limited to the following embodiments.

(Halogenated metal leaf)
FIG. 1 shows a cross-sectional view of the halogenated metal foil 1. As shown in FIG. 1, the metal halide foil 1 is composed of a modified layer 2 in which the surface of metal particles is modified with a halide, and a metal portion 3.

In the present embodiment, the halogenated metal foil 1 is modified in which the surface of the metal foil containing Li, Na and K metals is modified with a halogen element (at least one of fluorine, chlorine, bromine, iodine, astatine and tennessine). It is preferable to have the layer 2 and the metal portion 3.

According to such a configuration, Li, Na, K, and a metal are melted to form a metal foil, and the surface thereof is modified with a halogen element to form a metal foil having a modified layer, whereby the metal foil is firmly bonded to the metal portion. It becomes possible to uniformly form the modified layer. As a result, the destruction of the modified layer due to the volume change when charging and discharging are repeated is reduced, a uniform electrochemical reaction occurs, dendrite precipitation is suppressed, and the cycle characteristics can be improved.

In the present embodiment, the halogenated metal foil 1 preferably includes a modified layer in which the distribution amount of the halogen elements is present in a gradation pattern. The term "gradation" here means that the amount of halogen element distributed is continuously changing.

According to this configuration, the amount of halogen elements distributed in the modified layer changes in a gradation manner, so that the modified layer firmly bonded to the metal portion can be made flexible. This makes it possible to relieve stress due to volume changes when charging and discharging are repeated, further reducing the destruction of the modified layer, and enabling a uniform electrochemical reaction in which dendrite precipitation is suppressed. .. This makes it possible to further improve the cycle characteristics.

In the present embodiment, in the halogenated metal foil 1, it is preferable that the amount of halogen element distributed in the gradation decreases toward the metal portion.

According to this configuration, by forming the distribution amount of the halogen element into a gradation shape that decreases toward the metal portion, it is possible to give more flexibility to the modified layer that is firmly bonded to the metal portion. .. This makes it possible to relieve stress due to volume changes when charging and discharging are repeated, further reducing the destruction of the modified layer, and enabling a uniform electrochemical reaction in which dendrite precipitation is suppressed. .. This makes it possible to further improve the cycle characteristics.

In the present embodiment, it is preferable that the modified layer contains at least one selected from the group consisting of iodide, fluoride, chloride and bromide.

According to such a configuration, Li, Na and K metals are melted and formed into a metal foil, and the surface thereof is modified into iodide, fluoride, chloride and bromide, whereby the modification is firmly bonded to the metal portion. The layer can be provided with an iodide conduction function, allowing for a more uniform electrochemical reaction. This makes it possible to further improve the cycle characteristics.

In the present embodiment, the halogenated metal foil 1 preferably has a thickness of 20 μm to 1000 μm.

According to this configuration, the metal foil having a thickness of 20 μm to 1000 μm improves the handleability when manufacturing the electrode. This makes it possible to fabricate a homogeneous electrode, reduce the destruction of the modified layer due to local volume changes when charging and discharging are repeated, and enable a uniform electrochemical reaction in which dendrite precipitation is suppressed. Become. This makes it possible to further improve the cycle characteristics.

In the present embodiment, the halogenated metal foil 1 preferably has a modified layer having a thickness of more than 10 nm and less than 5 μm.

According to such a configuration, when the thickness of the modified layer is larger than 10 nm and smaller than 5 μm, it becomes possible to produce a homogeneous electrode having low internal resistance, and a uniform electrochemical reaction becomes possible. As a result, the destruction of the modified layer due to the volume change when the charging / discharging is repeated is further reduced, and the dendrite precipitation can be further suppressed. This makes it possible to further improve the cycle characteristics.

In the all-solid-state battery according to the present disclosure, it is preferable to use the halogenated metal foil 1 as a positive electrode or a negative electrode.

According to such a configuration, the destruction of the modified layer due to the volume change when the charging / discharging is repeated is reduced, and a uniform electrochemical reaction in which the precipitation of dendrite is suppressed becomes possible. This makes it possible to improve the cycle characteristics.

In the lithium ion battery according to the present disclosure, it is preferable to use the halogenated metal foil 1 as a positive electrode or a negative electrode.

According to such a configuration, the destruction of the modified layer due to the volume change when the charging / discharging is repeated is reduced, and a uniform electrochemical reaction in which the precipitation of dendrite is suppressed becomes possible. This makes it possible to improve the cycle characteristics.

(Manufacturing method of halogenated metal leaf)
A method for producing a metal halide foil will be described by taking the case of a lithium halogenated foil as an example.
(Lithium foil manufacturing process)
First, a lithium ingot is added to the hydrocarbon oil, heated above the melting point of lithium, the molten lithium-hydrocarbon oil mixture is stirred for a sufficient time, and then cast on a heat-resistant resin to prepare a lithium foil. ..
(Steam reforming process)
Next, the produced lithium foil is sprayed with halogen gas for a desired modification time to modify the surface of the lithium foil and cool it to obtain a halogenated lithium foil.

It is preferable that all the steps are performed in an atmosphere of an inert gas such as argon or helium so that the molten lithium or the lithium foil does not react.

The hydrocarbon oil is preferably 1 to 30 parts by weight, more preferably 2 to 15 parts by weight, when the lithium ingot is 1 part by weight, from the viewpoint of uniformly melting.

The stirring time of the molten lithium-hydrocarbon oil mixture is preferably 1 minute or more. It is preferable from the viewpoint of uniformly melting.

The stirring speed of the molten lithium-hydrocarbon oil mixture is preferably 500 rpm or more. It is desirable from the viewpoint of uniformly melting.

The reforming time of the surface reforming step is preferably 10 seconds or more. It is preferable from the viewpoint of modifying the entire surface of the lithium foil.

The gradation of the distribution amount of halogen elements in the direction from the surface side of the halogenated metal foil to the metal portion should be controlled by the modification time and temperature of the surface modification step, the amount of gas blown and its temperature, and a combination thereof. Can be done.

(Battery manufacturing method)
A method for manufacturing a battery using a metal halide foil will be described by taking the case of the lithium halide foil prepared as described above as an example.

(Lithium-ion secondary battery)
FIG. 2 shows a schematic cross-sectional view of the lithium ion secondary battery using the halogenated metal foil of the present embodiment.

<Negative electrode>
(Current collector for negative electrode)
The current collector 22 for the negative electrode may be a conductive plate material, and for example, a thin metal plate (metal foil) such as copper, nickel or an alloy thereof, or stainless steel can be used.

(Negative electrode active material layer)
The negative electrode active material layer 24 is formed by crimping the lithium halogenated foil prepared as described above onto the negative electrode current collector 22. In this way, the negative electrode 20 can be manufactured.

The crimping method is not particularly limited, and a known method such as a hand press or a roller press can be used.

A negative electrode binder for improving the bonding between the metal halide foil and the negative electrode current collector may be contained between the negative electrode active material layer and the negative electrode current collector layer.

(Binder for negative electrode)
The negative electrode binder joins the negative electrode active material and the negative electrode current collector 22. The binder may be any binder that can be bonded as described above, and examples thereof include fluororesins such as polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE). Further, in addition to the above, as the binder, for example, cellulose, styrene / butadiene rubber, ethylene / propylene rubber, polyimide resin, polyamide-imide resin and the like may be used. Further, as the binder, an electron conductive conductive polymer or an ion conductive conductive polymer may be used. Examples of the electron-conducting conductive polymer include polyacetylene and the like. In this case, since the binder also exerts the function of the conductive auxiliary agent particles, it is not necessary to add the conductive auxiliary agent. As the ionic conductive polymer, for example, a polymer having ionic conductivity such as lithium ion can be used, and for example, a polymer compound (polyether-based polymer compound such as polyethylene oxide or polypropylene oxide) can be used. , Polyphosphazene, etc.) and a lithium salt such as LiClO ₄ , LiBF ₄ , LiPF ₆ or an alkali metal salt mainly composed of lithium, and the like. Examples of the polymerization initiator used for the complexing include a photopolymerization initiator or a thermal polymerization initiator compatible with the above-mentioned monomers.

The halogenated metal leaf may be used for pre-doping the positive electrode active material or the negative electrode active material. In particular, when an active material having a large initial irreversible capacity is used, it is effective from the viewpoint of improving the cycle characteristics. The predoping method is not particularly limited, but can be performed by the following method.

(Manufacturing method of lithium pre-doped negative electrode)
For example, the lithium halide foil is attached and pressed onto a negative electrode active material layer such as metallic silicon (Si) and silicon oxide (SiO _x ) formed on a current collector for a negative electrode to obtain a negative electrode active material. Lithium doping proceeds, and a lithium pre-doped negative electrode is completed.

The press method is not particularly limited, and a known method such as a hand press or a roller press can be used.

<Positive electrode>
(Current collector for positive electrode)
The current collector 12 for the positive electrode may be a conductive plate material, and for example, a thin metal plate (metal foil) such as aluminum or an alloy thereof or stainless steel can be used.

(Positive electrode active material layer)
The positive electrode active material layer 14 is mainly composed of a positive electrode active material, a positive electrode binder, and a necessary amount of a positive electrode conductive auxiliary agent. These are dispersed in a solvent, coated on the positive electrode current collector 12, dried, and pressure-bonded as necessary to form the positive electrode active material layer 14. In this way, the positive electrode 10 can be manufactured.

The crimping method is not particularly limited, and a known method such as a hand press or a roller press can be used.

(Positive electrode active material)
As the positive electrode active material, occlusion of lithium ions and release, desorption and insertion of lithium ions (intercalation), or counter anions of the lithium ions and the lithium ions (e.g., PF 6 ^_-) and doping and dedoping Is not particularly limited as long as it is possible to reversibly proceed, and a known electrode active material can be used. For example, lithium cobalt oxide (LiCoO _2), lithium nickel oxide (LiNiO _2), lithium manganese spinel (LiMn ₂ O _4), and the general _{formula: LiNi x Co y Mn z M} a O 2 (x + y + z + a = 1,0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ z ≦ 1, 0 ≦ a ≦ 1, M is represented by one or more elements selected from Al, Mg, Nb, Ti, Cu, Zn, and Cr). Composite metal oxide, lithium vanadium compound (LiV ₂ O ₅ , Li ₃ V ₂ (PO ₄ ) ₃ ), olivine type LiMPO ₄ (where M is Co, Ni, Mn, Fe, Mg, V, Nb, Ti , Al, showing one or more elements or VO selected from Zr), lithium titanate _{(Li 4 Ti 5 O 12)} , LiNi x Co y Al z O 2 (0.9 <x + y + z <1.1) , etc. Composite metal oxides of.

(Binder for positive electrode)
The binder for the positive electrode is not particularly limited, and the same binder as the binder for the negative electrode described above can be used.

(Conductive aid for positive electrode)
The conductive auxiliary agent for the positive electrode is not particularly limited, and any known conductive auxiliary agent can be used as long as it improves the electron conductivity of the positive electrode active material layer 14. Examples thereof include carbon-based materials such as graphite and carbon black, metals such as copper, nickel, stainless steel and iron, mixtures of carbon materials and fine metal powders, and conductive oxides such as ITO.

<Electrolyte>
The electrolyte is contained inside the positive electrode active material layer 14, the negative electrode active material layer 24, and the separator 18. The electrolyte is not particularly limited, and for example, in the present embodiment, an electrolytic solution containing a lithium salt can be used.

As the electrolytic solution, it is preferable to use an organic solvent that can operate at a high voltage, for example, an aprotic high dielectric constant solvent such as ethylene carbonate or propylene carbonate, or an acetic acid ester such as dimethyl carbonate or ethyl methyl carbonate. Or aprotic low-viscosity solvents such as propionic acid esters. Further, it is desirable to use these aprotic high dielectric constant solvents and aprotic low viscosity solvents in combination at an appropriate mixing ratio.

Further, as the organic solvent, an ionic liquid using imidazolium, ammonium, and a pyridinium type cation may be used. Although counter anion is not particularly ^{_{limited, BF 4 -, PF 6 -}} , (CF 3 SO 2) 2 N - , and the like, may be mixed with organic solvents described above.

The lithium salt is not particularly limited, and a lithium salt used as an electrolyte of a lithium ion secondary battery can be used. For example, inorganic acid anion salts such as LiPF ₆ , LiBF ₄ , LiClO ₄ , LiFSI, and LiBOB, and organic acid anion salts such as LiCF ₃ SO ₃ and (CF ₃ SO ₂ ) ₂ NLi can be used.

Further, the concentration of the lithium salt is preferably 0.5 to 2.0 M from the viewpoint of electrical conductivity. The conductivity of this electrolyte at a temperature of 25 ° C. is preferably 0.01 S / m or more, and is adjusted according to the type of lithium salt or its concentration.

When the electrolyte is a solid electrolyte or a gel electrolyte, poly (vinylidene fluoride) or the like can be contained as a polymer material.

Further, various additives may be added to the electrolytic solution of the present embodiment, if necessary. Examples of the additive include vinylene carbonate, methylvinylene carbonate, etc. for the purpose of improving the cycle life, biphenyl, alkylbiphenyl, etc. for the purpose of preventing overcharging, various carbonate compounds for the purpose of deoxidation and dehydration, and various types. Examples include carboxylic acid anhydrides, various nitrogen-containing and sulfur-containing compounds.

The lithium ion secondary battery is manufactured as follows, for example.

The negative electrode 20 produced in this manner, the positive electrode 10, and the separator 18 impregnated with the electrolyte are combined as shown in FIG. 2 and placed in an outer body such as a cylindrical tube or an aluminum laminate to seal the lithium ion secondary. The battery 100 can be manufactured. In the drawings, 60 and 62 indicate the extraction electrodes of the positive electrode and the negative electrode, respectively.

(All solid state battery)
FIG. 3 is a cross-sectional view showing an all-solid-state battery using the halogenated metal foil of the present embodiment. As shown in FIG. 3, the all-solid-state battery 110 is formed from the positive electrode current collector layer 111, the positive electrode active material layer 112, the negative electrode current collector layer 113, the negative electrode active material layer 114, the solid electrolyte layer 115, the positive electrode 116, and the negative electrode 117. It is composed.

<Negative electrode>
(Current collector for negative electrode)
The current collector layer 113 for the negative electrode may be a conductive plate material, and for example, copper, nickel or an alloy thereof, a metal thin plate (metal foil) such as stainless steel, metal particles, or a metal sputter film can be used. When metal particles are used, it is preferable to press-mold them by a known method such as a hand press or a roller press.

(Negative electrode active material layer)
The negative electrode active material layer 114 is formed by pressure-bonding the lithium halogenated foil prepared as described above onto the negative electrode current collector 113. In this way, the negative electrode 117 can be manufactured.

The crimping method is not particularly limited, and a known method such as a hand press or a roller press can be used.

A negative electrode binder for improving the bonding between the metal halide foil and the negative electrode current collector may be contained between the negative electrode active material layer and the negative electrode current collector layer. As the binder for the negative electrode, the same binder as that of the lithium ion secondary battery can be used.

<Positive electrode>
(Current collector for positive electrode)
For the positive electrode current collector 111, for example, aluminum or an alloy thereof, a metal thin plate (metal foil) such as stainless steel, metal particles, or a metal sputter film can be used. When metal particles are used, it is preferable to press-mold them by a known method such as a hand press or a roller press. When a metal paste is used, it may be applied and then heat-treated.

(Positive electrode active material layer)
The positive electrode active material layer 112 is mainly composed of a positive electrode active material, a positive electrode binder, an required amount of a positive electrode conductive auxiliary agent, and a positive electrode solid electrolyte, and these are dispersed in a solvent to form a positive electrode current collector. A method of coating, drying, and crimping as necessary on the 111, a method of placing the constituent members of the positive electrode active material layer on the positive electrode current collector 111 which has been pressure-molded, and pressure-molding the positive electrode active material layer. The positive electrode 116 can be manufactured by a method such as pressure molding a constituent member, sintering the constituent member, and sputter molding a positive electrode current collector 111 on the surface thereof.

The crimping method and pressure molding method are not particularly limited, and known methods such as a hand press and a roller press can be used.

As the conductive auxiliary agent for the positive electrode and the binder for the positive electrode, the same ones as those of the lithium ion secondary battery can be used.

As the positive electrode active material contained in the positive electrode active material layer 112 according to the present embodiment, for example, a lithium-containing compound such as a lithium oxide, a lithium sulfide, or an interlayer compound containing lithium is suitable, and two or more of these are suitable. May be mixed and used. In particular, in order to increase the energy density, a lithium composite oxide represented by the general formula Li _x MO ₂ or an intercalation compound containing lithium is preferable. In addition, M is preferably one or more kinds of transition metals, and specifically, at least one kind of Co, Ni, Mn, Fe, Al, V, and Ti is preferable. x varies depending on the charge / discharge state of the battery, and is usually a value within the range of 0.05 ≦ x ≦ 1.10. In addition, manganese spinel (LiMn ₂ O ₄ ) having a spinel-type crystal structure, lithium iron phosphate (LiFePO ₄ ) having an olivine-type crystal structure, LiCoPO ₄ , LiNiPO ₄ , etc. also have high energy densities. It is preferable because it can be obtained.

Specifically, as the positive electrode active material constituting the positive electrode active material layer 112 of the all-solid-state battery 110, it is preferable to use a material that efficiently releases and adsorbs lithium ions. For example, it is preferable to use a transition metal oxide or a transition metal composite oxide. Specifically, lithium manganese composite oxide Li ₂ Mn _x3 Ma _1-x3 O ₃ (0.8 ≦ x3 ≦ 1, Ma = Co, Ni), lithium cobaltate (LiCoO ₂ ), lithium nickelate (LiNiO ₂₎ ), Lithium manganese spinel (LiMn ₂ O ₄ ), and general formula: LiNi _{x4 Coy4} Mn _z4 O ₂ (x4 + y4 + z4 = 1, 0 ≦ x4 ≦ 1, 0 ≦ y4 ≦ 1, 0 ≦ z4 ≦ 1) Composite metal oxide, lithium vanadium compound (LiV ₂ O ₅ ), olivine type LiMbPO ₄ (however, Mb is one or more selected from Co, Ni, Mn, Fe, Mg, Nb, Ti, Al, Zr. (Elements of), Lithium vanadium phosphate (Li ₃ V ₂ (PO ₄ ) ₃ or LiVOPO ₄ ), Li excess solid solution positive Li ₂ MnO _3- LiMcO ₂ (Mc = Mn, Co, Ni), Lithium titanate (Li) ₄ Ti ₅ O _12), one of _{Li a Ni x5 Co y5 Al z5} O 2 (0.9 <a <1.3,0.9 <x5 + y5 + z5 <1.1), in a composite metal oxide represented by Is preferable. Further, the material is not limited to these materials, and is not particularly limited as long as it is a positive electrode active material material that electrochemically inserts and desorbs lithium ions.

The particle size of the positive electrode active material constituting the positive electrode active material layer 112 according to the present embodiment is preferably 0.05 μm or more and 5 μm or less from the viewpoint of forming the positive electrode active material layer 112 densely and thinly.

The thickness of the positive electrode active material layer 112 is not particularly limited, but is preferably 0.1 to 100 μm, preferably 0.3 to 20 μm, from the viewpoint of obtaining a high-capacity, high-output all-solid-state battery while improving cycle characteristics. More preferably.

When the constituent members of the positive electrode active material layer are sintered, a sintering aid may be included to improve the sintering.

When the positive electrode active material layer is prepared by sintering, the atmosphere thereof is not particularly limited, but it is preferable to carry out the preparation under conditions where the decomposition of the positive electrode active material and the valence of the contained metal do not change.

<Solid electrolyte layer>
The solid electrolyte layer 115 is composed of a solid electrolyte, and is mainly composed of a binder for a solid electrolyte and a sintering aid in an amount as required. A method in which these are dispersed in a solvent and applied to a PET film, dried, and bridged as necessary to form a self-supporting film, a method in which a component of the solid electrolyte layer is placed and pressure-molded, and a method of pressure molding the solid electrolyte layer. The solid electrolyte layer 115 can be produced by a method of pressure molding the constituent members and sintering the constituent members.

The crimping method and pressure molding method are not particularly limited, and are known such as a hand press, a roller press, a hydrostatic pressure press (WIP), a cold isotropic pressure press (CIP), and a hot isotropic pressure press (HIP). It is possible to use the method of.

The above-mentioned cross-linking method is not particularly limited, and a known method such as thermal cross-linking or UV cross-linking can be used by further adding a polymer material or a cross-linking agent to the constituent members of the solid electrolyte layer.
(Solid electrolyte)
As the solid electrolyte constituting the solid electrolyte layer 115 of the all-solid-state battery of the present embodiment, it is preferable to use a material having a small electron conductivity and a high lithium ion conductivity. For example, perovskite-type compounds such as La _0.5 Li _0.5 TiO ₃ , ricicon-type compounds such as Li ₁₄ Zn (GeO ₄ ) ₄ , garnet-type compounds such as Li ₇ La ₃ Zr ₂ O ₁₂ and LiTi ₂ ( PO ₄ ) ₃ , LiGe ₂ (PO ₄ ) ₃ , LiZr ₂ (PO ₄ ) ₃ , Li _1.5 Ca _0.5 Zr _1.5 (PO ₄ ) ₃ , Li _1.3 Al _0.3 Ti _{1. 7} (PO ₄ ) ₃ and Li _1.5 Al _0.5 Ge _1.5 (PO ₄ ) ₃ , Li ₃ PO ₄ and Li _3.5 Si _0.5 P _0.5 O ₄ and Li _2.9 PO Phosphate compounds such as _3.3 N _0.46 , thiolysicon-type compounds such as Li _3.25 Ge _0.25 P _0.75 S ₄ and Li ₃ PS ₄ , Li ₂ SP ₂ S ₅ and Li ₂ O glass compounds such -V ₂ O ₅ -SiO _2, a LiI and _{Li 3 YCl 6, Li 3 YBr} 6, Li 3 InCl 6, Li 3 InBr 6 at least one selected from the group consisting of halogen compounds, such as Is desirable.

The particle size of the solid electrolyte constituting the solid electrolyte layer of the all-solid-state battery of the present embodiment is preferably 0.05 μm or more and 5 μm or less from the viewpoint of forming a thin and dense layer.

The thickness of the solid electrolyte layer is not particularly limited, but is preferably 0.1 to 100 μm, more preferably 0.3 to 20 μm, from the viewpoint of realizing high rate characteristics while maintaining cycle characteristics.

By setting the thickness of the solid electrolyte layer to 0.1 to 100 μm, the moving distance of lithium ions in charge / discharge can be shortened while maintaining the insulating property of the solid electrolyte layer, and the internal resistance can be reduced.

When the solid electrolyte layer is prepared by sintering, the atmosphere thereof is not particularly limited, but it is preferable to carry out the solid electrolyte layer under conditions where the solid electrolyte is not decomposed or deteriorated.

(Sintering aid)
The type of the sintering aid added to the positive electrode active material layer 112 and the solid electrolyte layer 115 constituting the all-solid-state battery 110 is not particularly limited as long as the temperature of the sintering can be lowered, but lithium carbonate or hydroxide is not particularly limited. It is preferable to use a lithium compound such as lithium, lithium phosphate, lithium niobate, a boron compound such as H3BO3, and a compound composed of lithium and boron. These materials are preferable because the compound form is not easily changed by water or carbon dioxide, so that they can be weighed in air and can be added easily and accurately.

(Lithium ion conduction aid)
A lithium ion conduction aid may be added to the positive electrode active material layer according to the present embodiment for the purpose of improving lithium ion conductivity. The lithium ion conduction aid used in the present embodiment is not particularly limited, and a well-known material can be used.

As the lithium ion conduction aid, it is preferable to use a material having high lithium ion conductivity. For example, perovskite-type compounds such as La _0.5 Li _0.5 TiO ₃ , ricicon-type compounds such as Li ₁₄ Zn (GeO ₄ ) ₄ , garnet-type compounds such as Li ₇ La ₃ Zr ₂ O ₁₂ and LiTi ₂ ( PO ₄ ) ₃ , LiGe ₂ (PO ₄ ) ₃ , LiZr ₂ (PO ₄ ) ₃ , Li _1.5 Ca _0.5 Zr _1.5 (PO ₄ ) ₃ , Li _1.3 Al _0.3 Ti _{1. 7} (PO ₄ ) ₃ and Li _1.5 Al _0.5 Ge _1.5 (PO ₄ ) ₃ , Li ₃ PO ₄ and Li _3.5 Si _0.5 P _0.5 O ₄ and Li _2.9 PO Phosphate compounds such as _3.3 N _0.46 , thiolysicon-type compounds such as Li _3.25 Ge _0.25 P _0.75 S ₄ and Li ₃ PS ₄ , Li ₂ SP ₂ S ₅ and Li ₂ O glass compounds such -V ₂ O ₅ -SiO _2, a LiI and _{Li 3 YCl 6, Li 3 YBr} 6, Li 3 InCl 6, Li 3 InBr 6 at least one selected from the group consisting of halogen compounds, such as Is desirable.

Further, the ratio of the lithium ion conduction aid to be added is not particularly limited as long as the positive electrode active material contained in each positive electrode active material layer has an electrochemical function. For example, the ratio of the positive electrode active material / lithium ion conduction aid is 100/0 to 60 in volume ratio from the viewpoint of reducing the internal resistance in order to obtain a higher capacity and higher output all-solid-state battery while improving the cycle characteristics. It is preferably in the range of / 40.

The all-solid-state battery 110 is manufactured as follows, for example.
As a method for producing the all-solid-state battery 110, a simultaneous firing method may be used, or a sequential firing method or a solid polymer method may be used. The co-fired method is a method in which the materials forming each layer are laminated and a laminated body is produced by batch firing. The sequential firing method is a method in which each layer is produced in order, and a firing step is inserted each time each layer is produced. The solid polymer method is a method of adhering each layer using a solid polymer as a binder, and is very convenient because it is only bonded. Hereinafter, a method for manufacturing the all-solid-state battery 110 will be described by taking the case of using the co-fired method as an example.

First, a solid electrolyte, a binder for a solid electrolyte, a sintering aid, and these are dispersed in a solvent to prepare a solid electrolyte slurry. The prepared solid electrolyte slurry is applied and molded to prepare a solid electrolyte green sheet.
Secondly, the positive electrode active material, the positive electrode binder, the positive electrode conductive auxiliary agent, and the lithium ion conductive auxiliary agent are dispersed in a solvent to prepare a positive electrode active material slurry. Further, the positive electrode current collector powder and the positive electrode active material powder are dispersed in a solvent to prepare a positive electrode current collector paste. The prepared positive electrode active material slurry is applied to one surface of the solid electrolyte green sheet and dried. Then, the positive electrode current collector paste is applied and dried so as to overlap the dried positive electrode active material paste. This is press-molded while heating, and then cut to prepare a laminate. By firing the produced laminate, a sintered body in which the positive electrode 116 and the solid electrolyte layer 115 are integrated is produced. The obtained sintered body is dried to sufficiently remove water and transferred into the glove box.
Third, a negative electrode active material layer is formed by crimping a lithium halogenated foil on the negative electrode current collector in the glove box. In this way, the negative electrode 117 is manufactured.
Fourth, a solid polymer membrane having lithium ion conductivity is produced. A solid polymer film is prepared by dissolving a solid polymer powder and a lithium salt in a solvent in a glove box, applying and drying on a PET film. The solid polymer membrane may be subjected to thermal cross-linking or UV cross-linking in order to improve the handleability.
Fifth, in the glove box, one surface of the solid polymer film was attached onto the negative electrode prepared above. Then, the surface of the solid electrolyte layer of the sintered body produced above and the other surface of the solid polymer membrane were bonded to each other, and finally sealed in a 2032 type coin cell.
The sealing method is not particularly limited. Depending on the purpose, application, and shape, for example, it may be sealed in a resin, an aluminum laminate, a cylindrical exterior body, or the like.

The method for producing the solid electrolyte slurry and the positive electrode active material slurry is not particularly limited. For example, each member of the solid electrolyte layer or each member of the positive electrode active material layer is wet-mixed with the vehicle to obtain a paste. As the wet mixing method, for example, a rotation / revolution mixer, a homogenizer method, a ball mill method, or the like can be used.

The method of applying and forming the solid electrolyte green sheet or the positive electrode active material layer is not particularly limited, but a doctor blade, a comma roll, a screen printing method or the like can be used.

The method for producing the solid electrolyte laminate is not particularly limited, but known methods such as a hand press, a roller press, a hydrostatic pressure press (WIP), a cold isotropic pressure press (CIP), and a hot isotropic pressure press (HIP) are known. It is possible to use the method.

The atmosphere of the solid electrolyte layer and the positive electrode active material layer is not particularly limited, but it is preferable that the solid electrolyte layer and the positive electrode active material are decomposed and the valence of the contained metal does not change.

Although the preferred embodiment of the present disclosure has been described above, the present disclosure is not limited to the above embodiment.

Next, Examples and Comparative Examples of the present disclosure will be specifically described. The examples shown below are examples, and the present disclosure is not limited thereto, and can be arbitrarily changed as long as the effects of the present disclosure are not impaired.

[Example 1]
(Halogenated lithium foil manufacturing process)
This was performed in a glove box having a dew point of −99 ° C. and an oxygen concentration of 1 ppm in which argon gas was circulated. Each of the glow boxes is equipped with an adsorption tower that adsorbs water or oxygen, and the dew point or oxygen concentration in the glove box can be controlled independently. The inside of the water and oxygen adsorption tower is filled with zeolite that mainly adsorbs water and oxygen, respectively. For example, Zeolite A-3 and SA-600A of Tosoh Corporation can be mentioned as zeolites that mainly adsorb water or oxygen, respectively. 100 g of lithium ingot from Kanto Chemical Co., Inc. and Carnation hydrocarbon oil from Witco Co., Ltd. were added to the stainless steel resin flask reactor, and the inside of the container was replaced with dry argon. The reactor was then heated to 200 ° C. to melt the lithium. The mixture was stirred for a stirring time of 5 minutes at a stirring speed of 500 rpm to uniformly melt the lithium ingot to obtain molten lithium. Then, a lithium foil was prepared by casting molten lithium on a stainless steel metal plate using an applicator having a Gap of 20 μm. Then, as a surface reforming step, iodine gas was sprayed on the produced lithium foil. The reforming time was 5 minutes. Finally, by washing with hexane, a metal foil having a modified layer and a lithium iodide foil were prepared.

<Measurement of thickness of halogenated metal leaf>
The thickness of the produced lithium iodide foil was 19 μm as measured in a non-exposed environment using a micrometer.
<Analysis of thickness and composition of modified layer>
It was confirmed by XRD measurement that the modified layer of the produced lithium iodide foil was lithium iodide and the metal part was lithium. Further, when the element distribution of the lithium iodide foil was observed using LA-ICP-MS from the surface side of the modified layer toward the metal portion side, lithium was found from the surface side of the modified layer toward the metal portion side. A gradation region where the ratio of iodine elements was continuously changing was confirmed. The thickness of the modified layer was 500 nm. Here, the thickness of the modified layer is defined as a region where the iodine element exists from the surface of the modified layer to the metal portion side.

(Preparation of negative electrode)
The lithium iodide foil produced by the above method was placed on one surface of a copper foil having a thickness of 12 μm as a negative electrode current collector, covered with a PET film, and pressure-bonded with a force of 20 kN to prepare a negative electrode. The negative electrode current collector was provided with a portion in which the lithium iodide foil did not exist in order to weld the external lead terminal (lead).

(Preparation of positive electrode)
96% by weight of lithium cobalt oxide as a positive electrode active material, 2% by weight of carbon black as a conductive auxiliary agent, 0.5% by weight of graphite, 1.5% by weight of PVDF as a binder, and N-methyl-2. -A paste-like positive electrode active material slurry was prepared by mixing and dispersing with a graphite solvent. Then, using a comma roll coater, the positive electrode active material slurry was uniformly applied to an aluminum foil having a thickness of 20 μm. Next, the N-methyl-2-pyrrolidone solvent in the positive electrode active material slurry was dried in an air atmosphere at 110 ° C. in a drying furnace to prepare a positive electrode having a positive electrode mixture layer on one side. The aluminum current collector was provided with a portion to which the positive electrode active material slurry was not applied in order to weld the external lead terminal (lead). Next, the positive electrode was pressed with a roll press so as to have a predetermined density.

(Manufacturing of lithium-ion secondary battery for evaluation)
Aluminum foil (width 4 mm, length 40 mm, thickness 100 μm) and nickel foil (width 4 mm, length 40 mm, thickness 100 μm) were ultrasonically welded to the positive electrode and the negative electrode produced above as external lead-out terminals, respectively. In order to improve the sealing property between the external terminal and the exterior body, a polypropylene film grafted with maleic anhydride was wound around the external lead-out terminal and heat-bonded. A battery element having a positive electrode, a negative electrode, and a separator made of a polyethylene microporous film sandwiched between them was placed in an exterior body (aluminum laminate pack) to make a bag. A 1M LiPF ₆ solution (solvent: ethylene carbonate / diethyl carbonate = 3/7 (volume ratio)) was injected into this aluminum laminate pack and then vacuum-sealed to prepare a lithium-ion secondary battery for evaluation. did.

<Evaluation method of cycle characteristics>
The cycle characteristics of the evaluation lithium ion secondary batteries produced in Examples and Comparative Examples were measured in a constant temperature bath at a temperature of 25 ° C. using a secondary battery charge / discharge test device (manufactured by Hokuto Denko Co., Ltd.). A charge / discharge cycle of charging at a constant current constant voltage up to 4.2 V at 0.2 C and discharging at a constant current up to 3 V at 0.2 C was repeated for 30 cycles. The capacity retention rate was calculated by dividing the discharge capacity at the 30th cycle by the discharge capacity at the 1st cycle, and evaluated as a cycle characteristic.

[Examples 2-49]
Examples 2 to 49 were prepared and tested in the same manner as in Example 1 except that the surface reforming steps were as described in Tables 1 and 2.

[Comparative Example 1]
A lithium ion secondary battery for evaluation of Comparative Example 1 was prepared and tested in the same manner as in Example 1 except that a metallic lithium foil (100 μm) manufactured by Honjo Chemical Co., Ltd. was used instead of the lithium iodide foil. ..

[Example 50]
In this example, an all-solid-state battery using the halogenated metal foil produced in Example 4 was produced.

(Preparation of solid electrolyte green sheet)
First, a powder of LiZr ₂ (PO ₄ ) ₃ was prepared as a solid electrolyte. Next, 100 parts of ethanol and 200 parts of toluene were added as solvents to 100 parts of LiZr ₂ (PO ₄ ) ₃ powder with a ball mill and wet-mixed. Then, 16 parts of a polyvinyl butyral binder and 4.8 parts of benzylbutyl phthalate were further added and mixed to prepare a solid electrolyte slurry. This solid electrolyte slurry was formed into a sheet on a PET film substrate by the doctor blade method and dried to prepare a solid electrolyte green sheet having a thickness of 40 μm.

(Preparation of positive electrode active material paste)
A powder of Li ₃ V ₂ (PO ₄ ) ₃ was prepared as the positive electrode active material. To 100 parts of Li ₃ V ₂ (PO ₄ ) ₃ powder, 15 parts of ethyl cellulose as a binder and 65 parts of dihydroterpineol as a solvent were added, and kneaded and dispersed with a hybrid mixer to prepare a positive electrode active material paste.

(Preparation of positive electrode current collector paste)
After mixing copper powder and Li ₃ V ₂ (PO ₄ ) ₃ powder in a volume ratio of 80/20 as a positive electrode current collector paste, 10 parts of ethyl cellulose as a binder and 50 parts of dihydroterpineol as a solvent were added. In addition, a positive electrode current collector paste was prepared by kneading and dispersing with three rolls.

(Manufacturing of positive electrode layer unit)
The prepared positive electrode active material paste was formed on the solid electrolyte green sheet by screen printing and dried at 80 ° C. for 5 minutes. The thickness was 5 μm. Next, the positive electrode current collector paste was formed by screen printing so as to overlap the dried positive electrode active material paste, and dried at 80 ° C. for 5 minutes. In this way, the positive electrode active material paste and the positive electrode current collector paste were printed and dried on the solid electrolyte green sheet to obtain a positive electrode layer unit.

(Preparation of sintered body)
14 sheets of the prepared solid electrolyte green sheets were laminated to prepare a solid electrolyte laminate. Then, it was stacked on the produced solid electrolyte laminate with the side on which the positive electrode current collector paste of the positive electrode layer unit was printed face up. This was molded at a temperature of 80 ° C. and a pressure of 1000 kgf / cm2 (98 MPa), and then cut to prepare a laminate. After that, the temperature is raised to 900 ° C. at a firing rate of 200 ° C./hour in a nitrogen atmosphere, the temperature is maintained at that temperature for 0.5 hours, and after firing, natural cooling is performed to form the positive electrode layer and the solid electrolyte layer. An integrated sintered body was obtained. The resulting sintered body was vacuum dried overnight at 80 ° C. to sufficiently remove water.

(Preparation of solid polymer membrane)
Polyethylene oxide (PEO) powder was dissolved in dehydrated grade acetonitrile using a homogenizer. LiTFSI and O of PEO were dissolved by adding LiTFSI so that the Li / O ratio was 1/18. A PEO solution was prepared by adding a polymerization initiator and a cross-linking agent to the solution and dissolving the mixture. The prepared PEO solution was applied onto a PET film with a doctor blade. Then, a solid polymer membrane was produced by vacuum drying and UV irradiation.

(Preparation of negative electrode layer)
The lithium iodide foil prepared in Example 3 was placed on one surface of a copper foil having a thickness of 12 μm as a negative electrode current collector, covered with a PET film, and pressure-bonded with a force of 20 kN to prepare a negative electrode.

(Manufacturing of all-solid-state battery)
One surface of the solid polymer film was attached onto the lithium iodide foil of the negative electrode prepared above. Next, the surface of the solid electrolyte layer of the sintered body produced above and the other surface of the solid polymer membrane were bonded together. Finally, it was sealed in a 2032 type coin cell.

<Evaluation method of cycle characteristics of all-solid-state battery>
The cycle characteristics of the all-solid-state batteries produced in Examples and Comparative Examples were measured in a constant temperature bath at a temperature of 40 ° C. using a secondary battery charge / discharge test device (manufactured by Hokuto Denko Co., Ltd.). A charge / discharge cycle of constant current constant voltage charging up to 4.3 V at 0.1 C and constant current discharge up to 3 V at 0.1 C was repeated for 30 cycles. The capacity retention rate was calculated by dividing the discharge capacity at the 30th cycle by the discharge capacity at the 1st cycle, and evaluated as a cycle characteristic.

[Examples 51 to 53]
In this example, all solid state as in Example 50, except that the lithium chloride foil, lithium bromide foil, and lithium fluoride foil prepared in Examples 9, 15 and 21 were used instead of the lithium iodide foil. Batteries were made and tested.

[Comparative Example 2]
An all-solid-state battery was prepared and tested in the same manner as in Example 50, except that a metallic lithium foil (100 μm) manufactured by Honjo Chemical Co., Ltd. was used instead of the lithium iodide foil.

The evaluation results of Examples 1 to 53 and Comparative Examples 1 and 2 are shown in Tables 1 and 2. In Examples 1 to 53, high cycle characteristics were exhibited. On the other hand, in the cases of Comparative Examples 1 and 2, lower cycle characteristics were shown as compared with Examples 1 and 53.

By using the halogenated metal foil of the present disclosure, it is possible to provide a lithium ion secondary battery and an all-solid-state battery having improved cycle characteristics.

1 ... Metal halide foil, 2 ... Modified layer, 3 ... Metal part, 10 ... Positive electrode, 12 ... Positive electrode current collector, 14 ... Positive electrode active material layer, 18 ... Separator, 20 ... Negative electrode, 22 ... Negative electrode current collector , 24 ... Negative electrode active material layer, 30 ... Laminate, 50 ... Case, 52 ... Metal foil, 54 ... Polymer film, 60, 62 ... Leads, 100 ... Lithium ion secondary battery, 110 ... All-solid-state battery, 111 ... Positive electrode current collector layer, 112 ... positive electrode active material layer, 113 ... negative electrode current collector layer, 114 ... negative electrode active material layer, 115 ... solid electrolyte layer, 116 ... positive electrode, 117 ... negative electrode.

Claims (8)

A halogenated metal foil having a modified layer in which the surfaces of Li, Na and K metals are modified with a halogen element and a metal portion. The halogenated metal foil according to claim 1, further comprising the modified layer in which the distribution amount of the halogen elements is present in a gradation pattern. The metal halide foil according to claim 2, wherein the gradation reduces the distribution amount of the halogen element toward the metal portion. The metal halide foil according to any one of claims 1 to 3, wherein the modified layer contains at least one selected from the group consisting of iodide, fluoride, chloride and bromide. The halogenated metal foil according to any one of claims 1 to 4, wherein the thickness of the metal foil is 20 μm to 1000 μm. The metal halide foil according to any one of claims 1 to 5, wherein the modified layer has a thickness of more than 10 nm and less than 5 μm. An all-solid-state battery in which the metal halide foil according to any one of claims 1 to 6 is used as a positive electrode or a negative electrode. A non-aqueous lithium ion battery in which the metal halide foil according to any one of claims 1 to 6 is used as a positive electrode or a negative electrode.

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