JP2023112393A - All-solid battery - Google Patents

Abstract

To provide an all-solid battery capable of suppressing such a reaction that an inner surface of a metal container is reduced by a halide-based solid electrolyte, thereby preventing reduction in capacity retention caused by deterioration of the inner surface of the metal container.SOLUTION: In an all-solid battery 100, at least one of a positive electrode 10, a negative electrode 20, and a solid electrolyte layer 30 contains a halide-based solid electrolyte. An inner surface of a metal container 40 is at least partially coated with a coating layer 50. The coating layer 50 contains at least one or more kinds of metals selected from aluminum, nickel, titanium, and zirconium.SELECTED DRAWING: Figure 1

Description

The present invention relates to all-solid-state batteries.

Solid electrolytes conventionally used in all-solid-state batteries include oxide-based ones, sulfide-based ones, and hydride-based ones. In recent years, as solid electrolytes, development of halide-based solid electrolytes such as Li ₂ ZrCl ₆ and Li ₃ ZrCl ₆ has been advanced.

In addition, there is a metal container having a coating layer formed on the inner surface of the metal container that houses the power generation element of the all-solid-state battery.
For example, Patent Document 1 describes an all-solid battery in which a power generation element including a positive electrode, a negative electrode, and a solid electrolyte layer interposed between the positive electrode and the negative electrode is housed inside a metal container. In the power generation element described in Patent Document 1, at least one of the positive electrode, negative electrode and solid electrolyte layer contains a sulfide-based solid electrolyte. Patent Document 1 describes a metal container having a coating layer of gold or platinum formed on the inner surface.

JP 2021-012835 A

However, in an all-solid-state battery in which a power generation element containing a halide-based solid electrolyte as a solid electrolyte is housed in a metal container, the inner surface of the metal container and the halide-based solid electrolyte come into contact with each other, and the inner surface of the metal container is reduced. A reaction that deteriorates easily occurs, which has been a problem. The reaction in which the inner surface of the metal container is reduced and deteriorated is an irreversible reaction, and as this reaction progresses, the halide-based solid electrolyte of the power generation element is oxidized, resulting in a decrease in the capacity of the all-solid-state battery.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and is an all-in-one method that can suppress the reaction in which the inner surface of a metal container is reduced by a halide-based solid electrolyte, and can prevent the decrease in the capacity retention rate due to the deterioration of the inner surface of the metal container. An object of the present invention is to provide a solid-state battery.

In order to solve the above problems, the present inventor focused on a metal material that is difficult to be reduced even when it comes into contact with a halide-based solid electrolyte, and conducted extensive research.
As a result, the inner surface of the metal container is covered with a coating layer containing at least one selected from at least one metal selected from aluminum, nickel, titanium, and zirconium, an alloy containing the metal, and an oxide containing the metal. The present inventors have found that the coating should be performed with
That is, the present invention relates to the following inventions.

[1] A power generation element including a positive electrode, a negative electrode, and a solid electrolyte layer interposed between the positive electrode and the negative electrode;
and a metal container that houses the power generation element,
At least one of the positive electrode, the negative electrode and the solid electrolyte layer contains a halide-based solid electrolyte represented by the following formula (1),
At least part of the inner surface of the metal container is coated with a coating layer,
The coating layer contains at least one metal selected from aluminum, nickel, titanium, and zirconium, an alloy containing the metal, and an oxide containing the metal. solid state battery.
LiaEbGcXd (1)
(In formula (1), E is at least one element selected from the group consisting of Al, Sc, Y, Zr, Hf, and lanthanides. G is OH, BO ₂ , BO ₃ , BO ₄ , B _3O6 , _B4O7 , _{CO3 , NO3 , AlO2} , _SiO3 , _SiO4 , _{Si2O7 , Si3O9} , _{Si4O11 , Si6O18 , PO3 , PO4 , P2O7} , _{P3O10 , SO3 , SO4} , _SO5 , _{S2O3 , S2O4 , S2O5 , S2O6 , S2O7 , S2O8 , BF 4} , _PF6 , _BOB , (COO) ₂ , N, _AlCl4 , _CF3SO3 , _CH3COO , _CF3COO , and O. X is at least one group selected from the group consisting of F, Cl , Br, and I. 0.5≦a<6, 0<b<2, 0≦c≦6, and 0<d≦6.1.)

[2] The all-solid-state battery according to [1], wherein 90% or more of the surface area of the inner surface is covered with the covering layer.
[3] The all-solid-state battery according to [1] or [2], wherein the coating layer has a thickness of 0.05 μm or more.

[4] The all-solid-state battery according to any one of [1] to [3], wherein the negative electrode contains a negative electrode active material having an electrode potential in the range of 0.5 V or more based on the Li ⁺ /Li equilibrium potential.
[5] The all-solid-state battery according to [4], wherein the negative electrode active material contains titanium oxide.
[6] The all-solid battery according to [5], wherein the titanium oxide is lithium titanate.

[7] The all-solid battery according to any one of [1] to [6], wherein a collector layer is arranged between the inner surface of the metal container and the negative electrode.

In the all-solid-state battery of the present invention, at least one of the positive electrode, the negative electrode, and the solid electrolyte layer contains the halide-based solid electrolyte represented by formula (1), and at least part of the inner surface of the metal container is a coating layer and the coating layer contains at least one metal selected from aluminum, nickel, titanium, and zirconium, an alloy containing the metal, and an oxide containing the metal. Therefore, the all-solid-state battery can suppress the reaction in which the inner surface of the metal container is reduced by the halide-based solid electrolyte, and can prevent the deterioration of the inner surface of the metal container from decreasing the capacity retention rate.

FIG. 1 is a schematic cross-sectional view showing the all-solid-state battery of the first embodiment. FIG. 2 is a cross-sectional schematic diagram showing the all-solid-state battery of the second embodiment.

Hereinafter, the all-solid-state battery of the present embodiment will be described in detail with appropriate reference to the drawings. In the drawings used in the following description, the features of the present invention may be shown enlarged for convenience in order to make it easier to understand the features of the present invention. Therefore, the dimensional ratio of each component may differ from the actual one. The materials, dimensions, and the like exemplified in the following description are examples, and the present invention is not limited to them, and can be implemented with appropriate modifications without changing the gist of the invention.

<First embodiment>
[All-solid battery]
FIG. 1 is a schematic cross-sectional view showing the all-solid-state battery of the first embodiment. The all-solid-state battery 100 shown in FIG. 1 has a power generation element 70 and a metal container 40 that houses the power generation element 70 . The shape of the all-solid-state battery 100 is, for example, a flat shape such as a coin shape or a button shape.

(metal container)
The metal container 40 is cylindrical. The planar shape of the metal container 40 may be polygonal (eg, triangular, quadrangular, pentagonal, hexagonal, heptagonal, octagonal), circular, or elliptical.
The metal container 40 has a first container 41 and a second container 42 . As shown in FIG. 1, the first container 41 and the second container 42 are arranged to sandwich the power generation element 70 in the thickness direction of the power generation element 70 (the lamination direction of the positive electrode 10, the negative electrode 20, and the solid electrolyte layer 30). ing.

The edge of the first container 41 and the edge of the second container 42 are fitted with a gasket 60 interposed therebetween. The inside of the metal container 40 is sealed by a gasket 60 so as to be airtight. As the gasket 60, for example, one made of polypropylene, nylon, or the like can be used. When the gasket 60 is required to have heat resistance depending on the application of the all-solid-state battery 100, etc., it is preferable to use a heat-resistant resin as the material of the gasket 60. FIG. Examples of heat-resistant resins that can be used as the material of the gasket 60 include fluorine resins such as tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA), polyphenylene ether (PEE), polysulfone (PSF), and polyarylate (PAR). , polyether sulfone (PES), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), etc., and heat-resistant resins having a melting point exceeding 240° C. are preferred.
Further, when the all-solid-state battery 100 is applied to applications requiring heat resistance, a known material such as a glass hermetic seal can be used as the material of the gasket 60 .

The first container 41 and the second container 42 are conductors made of metal. The first container 41 also serves as a positive electrode terminal. As shown in FIG. 1 , the first container 41 and the positive electrode 10 are electrically connected by arranging the positive electrode 10 of the power generation element 70 in contact with the inner surface of the first container 41 . The second container 42 also serves as a negative electrode terminal. As shown in FIG. 1 , the second container 42 and the negative electrode 20 are electrically connected by arranging the negative electrode 20 of the power generating element 70 in contact with the inner surface of the second container 42 .

As the metal forming the first container 41 and the second container 42, for example, stainless steel, copper, nickel, aluminum, or the like can be used, and it is preferable to use stainless steel because it has high strength and is inexpensive. The first container 41 and the second container 42 may be made of the same material, or may be made of different materials.

At least a part of the inner surface of the first container 41 and the second container 42 is covered with the coating layer 50 . The coating layer 50 contains at least one metal selected from aluminum, nickel, titanium, and zirconium, an alloy containing the metal, and an oxide containing the metal. AlCu, AlMn, AlZr, NiCu, NiCr, NiFe, TiAlSn, TiPd, etc. can be used as the alloy containing the metal. As the oxide containing the metal, for example, aluminum oxide, titanium oxide, or the like can be used.

Since the coating layer 50 is less likely to be reduced by a halide-based solid electrolyte and can more effectively prevent a decrease in capacity retention rate due to deterioration of the inner surface of the metal container 40, it contains at least one selected from aluminum, nickel, titanium, and zirconium. It is preferably made of at least one kind of metal, and more preferably made of aluminum or nickel. It is particularly preferable that the coating layer 50 is made of aluminum, which is a light material with a small specific gravity. This is because it can contribute to improving the energy density of the all-solid-state battery 100 .

The coating layer 50 preferably consists of at least one selected from the metal, the alloy containing the metal, and the oxide containing the metal. The coating layer 50 contains, for example, gold, platinum, etc., in addition to at least one selected from the metal, the alloy containing the metal, and the oxide containing the metal, within a range in which the effects of the present embodiment can be obtained. may Even when the coating layer 50 contains gold and/or platinum, the reduction reaction of the inner surface of the metal container 40 by the halide-based solid electrolyte can be suppressed. When the coating layer 50 contains gold and/or platinum, the content of gold and/or platinum is preferably within a range that does not interfere with the energy density of the all-solid-state battery 100 .

Since the first container 41 and the second container 42 can more effectively prevent a decrease in the capacity retention rate due to deterioration of the inner surface of the metal container 40, 50% or more of the surface area of the inner surface is covered by the coating layer 50. It is preferably covered, and more preferably 90% or more of the surface area of the inner surface is covered with the coating layer 50. As shown in FIG. Most preferably. The ratio of the surface area of the inner surface covered with the coating layer 50 may be the same or different between the first container 41 and the second container 42 .

When only a part of the inner surface of the first container 41 is covered with the coating layer 50 , it is possible to more effectively prevent a decrease in the capacity retention rate due to deterioration of the inner surface of the metal container 40 . For example, the region where the contact is made preferably includes a region where the inner surface of the first container 41 and the positive electrode 10 of the power generation element 70 are arranged in contact with each other.
When only a part of the inner surface of the second container 42 is covered with the coating layer 50 , it is possible to more effectively prevent deterioration of the capacity retention rate due to deterioration of the inner surface of the metal container 40 . For example, the region where the contact is made preferably includes a region where the inner surface of the second container 42 and the negative electrode 20 of the power generating element 70 are arranged in contact with each other.

The coating layer 50 may be formed on at least part of the inner surface of the metal container 40, and may be formed only on the inner surface of the metal container 40 as shown in FIG. Instead, it may be formed on a part or the entire surface of the outer surface.

The thickness of the coating layer 50 is preferably 0.05 μm or more. When the thickness of the coating layer 50 is 0.05 μm or more, it is possible to more effectively prevent a decrease in the capacity retention rate due to deterioration of the inner surface of the metal container 40 . The thickness of the coating layer 50 is more preferably 0.07 μm or more, and even more preferably 0.08 μm or more. Even if the thickness of the coating layer 50 exceeds 0.10 μm, the effect of suppressing the deterioration of the capacity retention rate due to deterioration of the inner surface of the metal container 40 is not improved. Therefore, the thickness of the coating layer 50 is preferably 0.10 μm or less.

The thickness of the coating layer 50 can be measured by the following method using a fluorescent X-ray analyzer. That is, for five points, four points on a line perpendicular to an arbitrary point on the inner surface of the first container 41 and the second container 42 coated with the coating layer 50 and separated from the point at equal intervals, A method of measuring the thickness using a fluorescent X-ray analyzer and calculating the average value can be used.
The thickness of the coating layer 50 may be measured by cutting the first container 41 and the second container 42 and observing the cut surfaces using a microscope, or by using a beta ray test method. may

The coating layer 50 can be formed by a known method such as electroplating or sputtering. When the coating layer 50 is formed only partially on the inner surface of the first container 41 and/or the second container 42, for example, the coating is performed by a method using a known mask according to the method of forming the coating layer 50. A layer 50 can be formed. Specifically, of the inner surfaces of the first container 41 and/or the second container 42, a mask is provided using a known method in the region where the coating layer 50 is not formed, then the coating layer 50 is formed, and then The mask should be removed.

(power generation element)
Power generation element 70 includes positive electrode 10 , negative electrode 20 , and solid electrolyte layer 30 interposed between positive electrode 10 and negative electrode 20 , as shown in FIG. 1 . The planar shape of the solid electrolyte layer 30 may be polygonal (eg, triangular, quadrangular, pentagonal, hexagonal, heptagonal, octagonal), circular, or elliptical. It can be determined according to the planar shape, and may be similar to the planar shape of the metal container 40 .

In the all-solid-state battery 100 of this embodiment, the positive electrode 10, the negative electrode 20, and the solid electrolyte layer 30 all contain the halide-based solid electrolyte represented by Formula (1). The halide-based solid electrolyte represented by formula (1) contained in the power generating element 70 improves ion conductivity within the power generating element 70 . The halide-based solid electrolyte represented by formula (1) contained in the positive electrode 10, the negative electrode 20, and the solid electrolyte layer 30 may have different compositions, or may have the same composition partially or entirely. .

LiaEbGcXd (1)
(In formula (1), E is at least one element selected from the group consisting of Al, Sc, Y, Zr, Hf, and lanthanides. G is OH, BO ₂ , BO ₃ , BO ₄ , B _3O6 , _B4O7 , _{CO3 , NO3 , AlO2} , _SiO3 , _SiO4 , _{Si2O7 , Si3O9} , _{Si4O11 , Si6O18 , PO3 , PO4 , P2O7} , _{P3O10 , SO3 , SO4} , _SO5 , _{S2O3 , S2O4 , S2O5 , S2O6 , S2O7 , S2O8 , BF 4} , _PF6 , _BOB , (COO) ₂ , N, _AlCl4 , _CF3SO3 , _CH3COO , _CF3COO , and O. X is at least one group selected from the group consisting of F, Cl , Br, and I. 0.5≦a<6, 0<b<2, 0≦c≦6, and 0<d≦6.1.)

The halide-based solid electrolyte represented by formula (1) has good ion conductivity. Therefore, the all-solid-state battery 100 of this embodiment has a high discharge capacity. In addition, the halide-based solid electrolyte represented by formula (1) does not react with moisture to generate hydrogen sulfide gas, for example, like a sulfide-based solid electrolyte, and hydrogen sulfide gas is completely solid. It does not deteriorate the battery 100 and has excellent reliability.

Li is an essential element in the halide-based solid electrolyte represented by formula (1). In formula (1), a ranges from 0.5 to less than 6.
E is an essential element in the halide-based solid electrolyte represented by formula (1). E is at least one element selected from the group consisting of Al, Sc, Y, Zr, Hf, and lanthanides. Among these, E is preferably Zr because it becomes a halide-based solid electrolyte that provides the all-solid-state battery 100 with a higher ion conductivity. In formula (1), b is in the range of more than 0 and less than 2.

G is an element optionally contained in the halide-based solid electrolyte represented by formula (1). G is OH, _{BO2 , BO3 ,} BO4, _{B3O6 , B4O7} , CO3, _{NO3 , AlO2} , _SiO3 , _{SiO4 , Si2O7 , Si3O9 ,} Si _4O11 , _{Si6O18 , PO3 , PO4, P2O7, P3O10 , SO3 , SO4 , SO5 , S2O3 , S2O4 , S2O5 , S} from the group consisting of _2O6 , _S2O7 , _S2O8 , _BF4 , _PF6 , BOB, ( _COO ) ₂ , N _{, AlCl4} , _{CF3SO3 , CH3COO} , _{CF3COO ,} O At least one selected group. Among these, G is preferably SO ₄ because it becomes a halide-based solid electrolyte that provides the all-solid-state battery 100 with good stability on the reduction potential side. In formula (1), c ranges from 0 to 6.

In the halide-based solid electrolyte represented by formula (1), X is an essential element. X is at least one element selected from the group consisting of F, Cl, Br and I; Among these, X is preferably Cl because it becomes a halide-based solid electrolyte that provides an all-solid-state battery 100 with even higher ionic conductivity. In formula (1), d is in the range of more than 0 and 6.1 or less.
a, b, c, and d in formula (1) are appropriately determined within the above ranges according to the types of elements represented by A, E, G, and X in formula (1).

Specific examples of the halide-based solid electrolyte represented by formula (1) include Li ₂ ZrCl ₆ , Li ₂ ZrSO ₄ Cl ₄ , Li ₂ ZrF ₆ , Li ₂ ZrBr ₆ , Li ₂ ZrI ₆ , Li ₂ ZrSO _{4F4 , Li2ZrSO4Br4 , Li2ZrSO4I4 , Li2ZrCl5CH3COO and the like .} Among these, the halide-based solid electrolyte is preferably Li ₂ ZrCl ₆ or Li ₂ ZrSO ₄ Cl ₄ . This is because the all-solid-state battery 100 with high ionic conductivity and good stability on the reduction potential side can be obtained.

"positive electrode"
The positive electrode 10 includes a positive electrode active material and a halide-based solid electrolyte represented by Formula (1). The positive electrode 10 may contain, as a solid electrolyte, not only the halide-based solid electrolyte represented by formula (1), but also a solid electrolyte other than the halide-based solid electrolyte represented by formula (1). Other solid electrolytes include known solid electrolytes such as oxide-based solid electrolytes, sulfide-based solid electrolytes, and hydride-based solid electrolytes.

The content of the halide-based solid electrolyte represented by formula (1) contained in the positive electrode 10 can be, for example, 10% by mass to 70% by mass, preferably 10% by mass to 40% by mass. When the content of the halide-based solid electrolyte represented by the formula (1) is 10% by mass or more, the ionic conductivity in the positive electrode 10 is improved due to the inclusion of the halide-based solid electrolyte represented by the formula (1). The effect of making becomes remarkable. When the content of the halide-based solid electrolyte represented by formula (1) is 70% by mass or less, the content of the positive electrode active material can be sufficiently secured.

As the positive electrode active material, any positive electrode active material capable of intercalating and deintercalating lithium ions can be used, and for example, a known positive electrode active material used in lithium ion secondary batteries can be used.
For example, a composite metal oxide can be used as the positive electrode active material. Examples of the composite metal oxide include lithium cobaltate (LiCoO ₂ ), lithium nickelate (LiNiO ₂ ), lithium manganate (LiMnO ₂ ), lithium manganese spinel (LiMn ₂ O ₄ ), and general formula: LiNi _x Co _y Mn _z Ma _{O 2} compound (in the general formula, x + y + z + a = 1, 0 ≤ x < 1, 0 ≤ y < 1, 0 ≤ z < 1, 0 ≤ a < 1, M is Al, Mg, Nb , Ti, Cu, Zn, and one or more elements selected from Cr), lithium vanadium compound (LiV ₂ O ₅ ), olivine-type LiMPO ₄ (where M is Co, Ni, Mn, Fe, Mg, Nb, one or more elements selected from Ti _, Al _, and _Zr , or VO ₎ , lithium titanate ( _Li4Ti5O12 ), _{LiNixCoyAlzO2} ( _0.9 <x+y+z<1.1) etc. The positive electrode active material may be organic. Examples of organic materials include polyacetylene, polyaniline, polypyrrole, polythiophene, and polyacene.

The positive electrode active material may be a cation-free material. Examples of cation-free materials include FeF ₃ , conjugated polymers containing organic conductive substances, Chevrell phase compounds, transition metal chalcogenides, vanadium oxides, and niobium oxides. The cation-free material may be used alone or in combination. When the positive electrode active material is a cation-free material, for example, discharge is first performed. Cations are inserted into the positive electrode active material by discharging. Alternatively, cation-free materials may be chemically or electrochemically pre-doped with cations.

The positive electrode 10 may contain a conductive aid and/or a binder in addition to the positive electrode active material and the halide-based solid electrolyte represented by formula (1).
A conductive aid enhances the electronic conductivity between the positive electrode active materials. Examples of conductive aids that can be used include carbon powder, carbon nanotubes, carbon materials, metal fine powders, mixtures of carbon materials and metal fine powders, and conductive oxides. Examples of carbon powder include carbon black, acetylene black, and ketjen black. Examples of metal fine powders include fine powders of copper, nickel, stainless steel, iron, and the like.

The binder binds the positive electrode active materials together. A known binder can be used as the binder. The binder preferably has oxidation resistance and adhesiveness. Examples of binders include polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyamide (PA), polyimide (PI), polyamideimide (PAI), polybenzimidazole (PBI), and polyethersulfone (PES). , polyacrylic acid and its copolymer, polyacrylic acid and its copolymer metal ion crosslinked product, maleic anhydride-grafted polypropylene (PP) or polyethylene (PE), mixtures thereof, and the like can be used. . As the binder contained in the positive electrode 10, it is particularly preferable to use polyvinylidene fluoride (PVDF).

"negative electrode"
The negative electrode 20 includes a negative electrode active material and a halide-based solid electrolyte represented by formula (1). The negative electrode 20 may contain, as a solid electrolyte, not only the halide-based solid electrolyte represented by formula (1), but also a solid electrolyte other than the halide-based solid electrolyte represented by formula (1). Other solid electrolytes include known solid electrolytes such as oxide-based solid electrolytes, sulfide-based solid electrolytes, and hydride-based solid electrolytes.

The content of the halide-based solid electrolyte represented by formula (1) contained in the negative electrode 20 can be, for example, 10% by mass to 70% by mass, preferably 10% by mass to 30% by mass. When the content of the halide-based solid electrolyte represented by formula (1) is 10% by mass or more, the ionic conductivity in the negative electrode 20 is improved due to the inclusion of the halide-based solid electrolyte represented by formula (1). The effect of making becomes remarkable. When the content of the halide-based solid electrolyte represented by formula (1) is 70% by mass or less, the content of the negative electrode active material can be sufficiently secured.

As the negative electrode active material, any negative electrode active material capable of intercalating and deintercalating lithium ions can be used. For example, known negative electrode active materials used in lithium ion secondary batteries can be used.
Examples of negative electrode active materials include lithium titanate (LTO: Li _4-7 Ti ₅ O ₁₂ , eg Li ₄ Ti ₅ O ₁₂ ), titanium oxide (TiO ₂ ), Ni—TiO ₂ , titanium niobium oxide (TNO: TiNb ₂ O ₇ ), lithium oxide (LiO ₂ ), HTO (eg, H ₂ Ti ₁₂ O ₂₅ ), sulfur-modified polyacrylonitrile (SPAN), and the like can be used. The negative electrode active material is preferably a titanium oxide (a compound containing titanium and oxygen) because it forms a stable negative electrode 20 with low reactivity with the solid electrolyte. Specifically, lithium titanate (LTO: for example Li ₄ Ti ₅ O ₁₂ ), titanium oxide (TiO ₂ ), Ni—TiO ₂ , titanium niobium oxide (TNO: TiNb ₂ O ₇ ), and lithium titanate (LTO: for example Li ₄ Ti ₅ O ₁₂ ). ) is most preferred.

The negative electrode active material may be, for example, metallic lithium, metallic magnesium, lithium alloys, magnesium alloys, carbon materials, and substances that can be alloyed with cations. Carbon materials include, for example, graphite that can occlude and release ions (natural graphite, artificial graphite), carbon nanotubes, non-graphitizable carbon, easily graphitizable carbon, low-temperature fired carbon, and the like. Materials that can be alloyed with cations include, for example, silicon, tin, zinc, lead, antimony, and the like. Substances that can be alloyed with cations may be, for example, these elemental metals, or alloys or oxides containing these elements.

The negative electrode active material preferably has an electrode potential in the range of 0.5 V or more based on the Li ⁺ /Li equilibrium potential, for example. When the electrode potential of the negative electrode active material is 0.5 V (vs Li ⁺ /Li) or more, even if the negative electrode 20 is arranged in contact with the inner surface of the second container 42, the reaction between the coating layer 50 and lithium ions Also, the reaction between the negative electrode active material and lithium ions is more likely to occur. Therefore, the reaction between the coating layer 50 and lithium ions can be suppressed, and good battery characteristics can be obtained. The electrode potential of the negative electrode active material is preferably 1.0 V (vs Li ⁺ /Li) or more.

Among the negative electrode active materials described above, lithium titanate (LTO: Li ₄ Ti ⁵ _{O 12} (1.55 V (vs Li ⁺ /Li)), TiNb ₂ O ₇ (1.6 V (vs Li ⁺ /Li)), sulfur-modified polyacrylonitrile (SPAN) (2.0 V (vs Li ⁺ /Li)) etc.

The negative electrode 20 may contain a conductive aid and/or a binder in addition to the negative electrode active material and the halide-based solid electrolyte represented by Formula (1).
As the conductive aid contained in the negative electrode 20, the same conductive aid that may be contained in the positive electrode 10 can be used.
As the binder contained in the negative electrode 20, in addition to the binder that may be contained in the positive electrode 10, for example, cellulose, styrene/butadiene rubber, ethylene/propylene rubber, polyimide resin, polyamideimide resin, acrylic resin, etc. may be used. can. Cellulose includes, for example, carboxymethyl cellulose (CMC).

"Solid electrolyte layer"
The solid electrolyte layer 30 is made of a halide-based solid electrolyte represented by Formula (1). The solid electrolyte layer 30 is not only the halide-based solid electrolyte represented by Formula (1), but also a solid electrolyte other than the halide-based solid electrolyte represented by Formula (1). Materials other than the halide-based solid electrolyte may be contained. Other solid electrolytes include known solid electrolytes such as oxide-based solid electrolytes, sulfide-based solid electrolytes, and hydride-based solid electrolytes.

When the solid electrolyte layer 30 contains a material other than the halide-based solid electrolyte represented by formula (1), the content of the halide-based solid electrolyte represented by formula (1) contained in the solid electrolyte layer 30 is, for example, , 50% to 100% by weight, preferably 90% to 100% by weight. When the content of the halide-based solid electrolyte represented by formula (1) is 50% by mass or more, the effect of containing the halide-based solid electrolyte represented by formula (1) becomes remarkable.

[Method for manufacturing all-solid-state battery]
The all-solid-state battery 100 of this embodiment can be manufactured, for example, by the method described below.
First, the power generation element 70 is manufactured, for example, by the method described below.
Powder of the halide-based solid electrolyte represented by the formula (1) is placed in a cylindrical mold having a predetermined planar shape and height, and pressure-molded to form the solid electrolyte layer 30 .

Next, the negative electrode active material, the halide-based solid electrolyte represented by formula (1), and the conductive aid are kneaded to form a negative electrode mixture. Then, the negative electrode mixture is placed on the solid electrolyte layer 30 formed in the cylindrical mold and pressure-molded. Thereby, the negative electrode 20 integrated with the solid electrolyte layer 30 is formed.
Next, the positive electrode active material, the halide-based solid electrolyte represented by Formula (1), and the conductive aid are kneaded to form a positive electrode mixture. Then, the positive electrode mixture is placed on the solid electrolyte layer 30 on the opposite side of the negative electrode 20 formed in the cylindrical mold and pressure-molded. Thereby, the positive electrode 10 integrated with the solid electrolyte layer 30 and the negative electrode 20 is formed.

After that, the pellet-shaped power generating element 70 in which the positive electrode 10, the solid electrolyte layer 30, and the negative electrode 20 are laminated in this order and integrated is taken out from the cylindrical mold.
In the present embodiment, the case where the positive electrode 10 is formed after the negative electrode 20 is formed has been described as an example, but the negative electrode 20 may be formed after the positive electrode 10 is formed.

Next, the power generation element 70 is housed in the metal container 40 .
Specifically, the first container 41 and the second container 42 of the metal container 40 whose entire inner surface is covered with the coating layer 50 are prepared. Next, the power generation element 70 is installed in the first container 41 so that the positive electrode 10 is arranged in contact with the inner surface of the first container 41 . Then, the second container 42 is placed on the first container 41, and the gasket 60 is placed between the edges of the first container 41 and the edges of the second container 42 to fit them. As a result, the first container 41 and the positive electrode 10 are electrically connected, and the second container 42 and the negative electrode 20 are electrically connected. After that, the sides of the second container 42 are tightened, and the first container 41 and the second container 42 are sealed with the gasket 60 .
Through the steps described above, the all-solid-state battery 100 of the present embodiment is obtained.

In the all-solid-state battery 100 of the present embodiment, the positive electrode 10, the negative electrode 20, and the solid electrolyte layer 30 contain the halide-based solid electrolyte represented by the formula (1), and the metal container 40 (the first container 41 and the second container 42) is covered with a covering layer 50 at least partially. The coating layer 50 contains at least one metal selected from aluminum, nickel, titanium, and zirconium, an alloy containing the metal, and an oxide containing the metal. Therefore, the all-solid-state battery 100 of the present embodiment can suppress a reaction in which the inner surface of the metal container 40 is reduced by the halide-based solid electrolyte, and can prevent a decrease in the capacity retention rate due to deterioration of the inner surface of the metal container 40.

<Second embodiment>
FIG. 2 is a cross-sectional schematic diagram showing the all-solid-state battery of the second embodiment. The all-solid-state battery 200 shown in FIG. 2 has a power generation element 71 and a metal container 40 that houses the power generation element 71 . The all-solid-state battery 200 shown in FIG. 2 differs from the all-solid-state battery 100 shown in FIG. 1 only in that the power generation element 71 has the current collector layer 21 on the surface of the negative electrode 20 on the second container 42 side. . Therefore, in the all-solid-state battery 200 shown in FIG. 2, the same members as in the all-solid-state battery 100 shown in FIG.

As shown in FIG. 2 , a collector layer 21 is arranged between the inner surface of the second container 42 of the metal container 40 and the negative electrode 20 . The collector layer 21 is made of a highly conductive material. As the current collector layer 21, for example, it is preferable to use a metal such as silver, palladium, gold, platinum, aluminum, copper, nickel, stainless steel, iron, an alloy thereof, or a conductive resin. The collector layer 21 may be in powder, foil, punched, or expanded form.

The all-solid-state battery 200 of this embodiment can be manufactured, for example, by the method described below.
A pellet-shaped power generation element 70 is manufactured in the same manner as in the case of manufacturing the all-solid-state battery 100 of the first embodiment. Then, the power generation element 70 is installed in the first container 41 so that the positive electrode 10 is arranged in contact with the inner surface of the first container 41 . Next, the collector layer 21 is placed on the negative electrode 20 of the power generation element 70 . After that, the second container 42 is placed on the first container 41, and the gasket 60 is placed between the edges of the first container 41 and the edges of the second container 42 for fitting. As a result, the first container 41 and the positive electrode 10 are electrically connected, and the second container 42 and the negative electrode 20 are electrically connected via the collector layer 21 . After that, the sides of the second container 42 are tightened, and the first container 41 and the second container 42 are sealed with the gasket 60 .
Through the above steps, the all-solid-state battery 200 of the present embodiment is obtained.

In the all-solid-state battery 200 of the present embodiment, as in the all-solid-state battery 100 of the first embodiment, the positive electrode 10, the negative electrode 20, and the solid electrolyte layer 30 contain the halide-based solid electrolyte represented by formula (1). At least part of the inner surface of the metal container 40 (the first container 41 and the second container 42) is covered with the coating layer 50. As shown in FIG. For this reason, the all-solid-state battery 200 of the present embodiment can suppress the reaction in which the inner surface of the metal container 40 is reduced by the halide-based solid electrolyte, similarly to the all-solid-state battery 100 of the first embodiment. It is possible to prevent a decrease in the capacity retention rate due to the deterioration of the

In addition, in the all-solid-state battery 200 of the present embodiment, the collector layer 21 is arranged between the inner surface of the second container 42 of the metal container 40 and the negative electrode 20 . Therefore, the coating layer 50 covering the inner surface of the second container 42 and the negative electrode active material contained in the negative electrode 20 are less likely to come into contact with each other. Therefore, even when the reaction between the coating layer 50 and lithium ions occurs more easily than the reaction between the negative electrode active material and lithium ions, the reaction between the coating layer 50 and lithium ions is suppressed, and good battery characteristics are achieved. can get.

As described above, the embodiments of the present invention have been described in detail with reference to the drawings. , substitutions, and other modifications are possible.

For example, in the above-described embodiment, the case where all of the positive electrode 10, the negative electrode 20 and the solid electrolyte layer 30 contain the halide-based solid electrolyte represented by formula (1) was described as an example, but the present invention At least one of the positive electrode 10, the negative electrode 20, and the solid electrolyte layer 30 contains the halide-based solid electrolyte represented by the formula (1). For example, only the solid electrolyte layer 30 may contain the halide-based solid electrolyte represented by Formula (1), or only the solid electrolyte layer 30 and the negative electrode 20 may be represented by Formula (1). It may contain a halide-based solid electrolyte.

Further, the power generation element in the all-solid-state battery of the present invention may have a collector layer on the surface of the positive electrode 20 on the first container 41 side. The current collector layer arranged between the inner surface of the first container 41 of the metal container 40 and the positive electrode 10 is made of a material with high electrical conductivity. As the material of the collector layer, for example, metals such as silver, palladium, gold, platinum, aluminum, copper, nickel, titanium, stainless steel, alloys thereof, or conductive resins can be used. The collector layer may be in the form of powder, foil, punched or expanded.

In the above-described embodiment, the case of having a laminated battery element in which only one layer each of the positive electrode 10, the solid electrolyte layer 30, and the negative electrode 20 is laminated has been described as an example. The power generation element in the battery may be formed by stacking a plurality of structures in which the positive electrode 10, the solid electrolyte layer 30, and the negative electrode 20 are stacked. In this case, one end of each positive electrode 10 is electrically connected to the first container 41 via a known terminal. One end of each negative electrode 20 is electrically connected to the second container 42 via a known terminal. Furthermore, the power generation element in the all-solid-state battery of the present invention may be of a wound type in which a sheet-like laminate composed of the positive electrode 10, the solid electrolyte layer 30, and the negative electrode 20 is wound.

[Example 1]
The all-solid-state battery 100 of Example 1 shown in FIG. 1 was manufactured by the method shown below.
First, the power generation element 70 was manufactured by the method shown below.
100 mg of a solid electrolyte powder made of Li ₂ ZrCl ₆ (LZC) was placed in a cylindrical mold with a diameter of 10 mm, and a punch with a diameter of 10 mm was used to form a solid electrolyte layer 30 having a thickness of 600 μm under pressure of 6 kN. formed.

Next, a negative electrode active material made of lithium titanate (Li ₄ Ti ₅ O ₁₂ ), a solid electrolyte made of Li ₂ ZrCl ₆ (LZC), and a conductive aid made of carbon (SuperP, trade name; manufactured by Imerys) were weighed, mixed at a mass ratio of 65:30:5, and kneaded in a mortar for 15 minutes to obtain a negative electrode mixture. Then, 10 mg of the negative electrode mixture was placed on the solid electrolyte layer 30 formed in the cylindrical mold, and pressure-molded at 6 kN using a punch with a diameter of 10 mm. Thus, the negative electrode 20 with a thickness of 60 μm integrated with the solid electrolyte layer 30 was formed.

Next, a positive electrode active material made of lithium cobalt oxide (LiCoO ₂ ), a solid electrolyte made of Li ₂ ZrCl ₆ (LZC), and a conductive aid made of carbon (SuperP, trade name; manufactured by Imerys) were weighed. , and mixed at a mass ratio of 65:32.5:2.5 and kneaded in a mortar for 15 minutes to obtain a positive electrode mixture. Then, 11 mg of the positive electrode mixture was placed on the solid electrolyte layer 30 on the side opposite to the negative electrode 20 formed in the cylindrical mold, and pressure-molded at 20 kN using a punch with a diameter of 10 mm. Thus, the positive electrode 10 with a thickness of 60 μm integrated with the solid electrolyte layer 30 and the negative electrode 20 was formed.
After that, the pellet-shaped power generation element 70 of Example 1, in which the positive electrode 10, the solid electrolyte layer 30, and the negative electrode 20 were laminated in this order and integrated, was taken out from the cylindrical mold.

Next, a first container 41 and a second container 42 made of stainless steel and having a diameter of 20 mm and whose entire inner and outer surfaces were covered with a coating layer 50 made of aluminum were prepared.
The coating layer 50 of the first container 41 was formed using an electroplating method. Plating was carried out for 180 seconds using a toluene solution containing NaF-Al(C ₂ H ₅ ) ₃ as a plating bath, with a current value fixed at 1 mA. The coating layer 50 of the second container 42 was formed separately from the coating layer 50 of the first container 41 by electroplating under the same conditions as the coating layer 50 of the first container 41 .

The thickness of the formed coating layer 50 was measured by the following method using a fluorescent X-ray spectrometer (trade name: Primus IV, manufactured by Rigaku Corporation). That is, the thickness is measured at 5 points of 4 points on a line perpendicular to the center of the inner surface of the first container 41 and the second container 42 covered with the coating layer 50 and 5 mm away from the center, and the average value was used as the thickness of the coating layer 50. Table 1 shows the results.

Next, the power generation element 70 of Example 1 was placed in the first container 41 so that the positive electrode 10 was arranged in contact with the inner surface of the first container 41 . Then, the second container 42 is placed on the first container 41, and a gasket 60 (trade name: polypropylene gasket, manufactured by Hosensha) is placed between the edge of the first container 41 and the edge of the second container 42. was installed and mated. As a result, the first container 41 and the positive electrode 10 were electrically connected, and the second container 42 and the negative electrode 20 were electrically connected. After that, the side surface of the second container 42 was tightened, and the first container 41 and the second container 42 were sealed with the gasket 60 .
Through the above steps, the all-solid-state battery 100 of Example 1 having a diameter of 20 mm and a height of 1.2 mm was obtained.

[Examples 2 to 5]
Example 2 to Example 2 in the same manner as in Example 1 except that the current flow time was changed when the coating layer 50 was formed on the first container 41 and the second container 42 using an electroplating method. An all-solid-state battery 100 of Example 5 was obtained. The current flow time in Examples 2 to 5 was such that the thickness of the coating layer 50 in Example 1 and the current were adjusted so that the thickness of the coating layer 50 in Examples 2 to 5 was the thickness shown in Table 1. It was calculated in proportion to the relationship with the flowing time. The thickness of the coating layer 50 formed on the first container 41 and the second container 42 was measured in the same manner as in Example 1. Table 1 shows the results.

[Example 6]
Except for using a mixed solution containing nickel sulfate, nickel chloride, and boric acid as a plating bath when forming the coating layer 50 on the first container 41 and the second container 42 by electroplating, An all-solid-state battery 100 of Example 6 was obtained in the same manner as in Example 1. The thickness of the coating layer 50 formed on the first container 41 and the second container 42 was measured in the same manner as in Example 1. Table 1 shows the results.

[Examples 7 to 10]
In the same manner as in Example 6, except for changing the current flow time when forming the coating layer 50 on the first container 41 and the second container 42 using an electroplating method, Examples 7 to 7 An all-solid-state battery 100 of Example 10 was obtained. The current flow time in Examples 7 to 10 was such that the thickness of the coating layer 50 in Example 6 and the current were adjusted so that the thickness of the coating layer 50 in Examples 7 to 10 was the thickness shown in Table 1. It was calculated in proportion to the relationship with the flowing time. The thickness of the coating layer 50 formed on the first container 41 and the second container 42 was measured in the same manner as in Example 1. Table 1 shows the results.

[Example 11]
When the coating layer 50 is formed on the first container 41 and the second container 42 by electroplating, a titanium hydroxide-sodium hydroxide solution is used as the plating bath, and the current is applied for 120 seconds. Except for this, the all-solid-state battery 100 of Example 11 was obtained in the same manner as in Example 1. The thickness of the coating layer 50 formed on the first container 41 and the second container 42 was measured in the same manner as in Example 1. Table 1 shows the results.

[Examples 12 to 15]
Example 12 to Example 12 in the same manner as in Example 11 except that the current flow time was changed when the coating layer 50 was formed on the first container 41 and the second container 42 using an electroplating method. An all-solid-state battery 100 of Example 15 was obtained. The current flow time in Examples 12 to 15 was such that the thickness of the coating layer 50 in Example 11 and the current were adjusted so that the thickness of the coating layer 50 in Examples 12 to 15 was the thickness shown in Table 1. It was calculated in proportion to the relationship with the flowing time. The thickness of the coating layer 50 formed on the first container 41 and the second container 42 was measured in the same manner as in Example 1. Table 1 shows the results.

[Example 16]
Except that when the coating layer 50 was formed on the first container 41 and the second container 42 by electroplating, an ammonium fluorozirconate solution was used as the plating bath, and the current was applied for 180 seconds. , an all-solid-state battery 100 of Example 16 was obtained in the same manner as in Example 1. The thickness of the coating layer 50 formed on the first container 41 and the second container 42 was measured in the same manner as in Example 1. Table 1 shows the results.

[Examples 17 to 20]
In the same manner as in Example 16, except for changing the current flow time when forming the coating layer 50 on the first container 41 and the second container 42 using an electroplating method, Examples 17 to 17 An all-solid-state battery 100 of Example 20 was obtained. The current flow time in Examples 17 to 20 was such that the thickness of the coating layer 50 in Example 16 and the current were adjusted so that the thickness of the coating layer 50 in Examples 17 to 20 was the thickness shown in Table 1. It was calculated in proportion to the relationship with the flowing time. The thickness of the coating layer 50 formed on the first container 41 and the second container 42 was measured in the same manner as in Example 1. Table 1 shows the results.

[Example 21]
Before forming the coating layer 50 on the first container 41 and the second container 42 by electroplating, a masking tape is applied to the inner surfaces of the first container 41 and the second container 42 where the coating layer 50 is not to be formed. An all-solid-state battery 100 of Example 6 was obtained in the same manner as in Example 1 except that a mask consisting of was provided and then the coating layer 50 was formed, and the mask was removed after the coating layer 50 was formed.

The mask was formed by applying a masking tape having a shape covering 50% of the surface area of the inner surface of each of the first container 41 and the second container 42 . The region where the mask was provided was only the circular region concentric with the first container 41 and the second container 42 in plan view. The mask was removed by removing the masking tape. The thickness of the coating layer 50 formed on the first container 41 and the second container 42 was measured in the same manner as in Example 1. Table 2 shows the results.

[Examples 22 to 25]
All-solid-state batteries 100 of Examples 22 to 25 were obtained in the same manner as in Example 21, except that the range of the region where the mask was provided on the inner surfaces of the first container 41 and the second container 42 was changed. Ta. Also in Examples 22 to 25, the area where the mask was provided was only the circular area concentric with the first container 41 and the second container 42 in plan view. The thickness of the coating layer 50 formed on the first container 41 and the second container 42 was measured in the same manner as in Example 1. Table 2 shows the results.

[Examples 26 to 30]
Examples 1 to 5 were carried out in the same manner as in Examples 1 to 5, except that Li ₂ ZrSO ₄ Cl ₄ (LZSOC) was used as the solid electrolyte used to form the positive electrode 10, the negative electrode 20, and the solid electrolyte layer 30. All-solid-state batteries 100 of Examples 26 to 30 were obtained. In the all-solid-state batteries 100 of Examples 26 to 30, the same first container 41 and second container 42 as in Examples 1 to 5 were used, respectively.

[Example 31]
A current collector layer 21 made of copper and having a thickness of 10 μm is placed on the negative electrode 20 of the power generation element 70 , and then the second container 42 is placed on the first container 41 , and the edge of the first container 41 and the second container 42 are placed. An all-solid-state battery 200 of Example 31 shown in FIG. In the all-solid-state battery 200 of Example 31, the same first container 41 and second container 42 as in Example 1 were used.

[Example 32]
A current collector layer 21 made of copper and having a thickness of 10 μm is placed on the negative electrode 20 of the power generation element 70 , and then the second container 42 is placed on the first container 41 , and the edge of the first container 41 and the second container 42 are placed. An all-solid-state battery 200 of Example 32 shown in FIG. In the all-solid-state battery 200 of Example 32, the same first container 41 and second container 42 as in Example 21 were used.

[Example 33]
The implementation shown in FIG. 2 was carried out in the same manner as in Example 32, except that Li ₂ ZrSO ₄ Cl ₄ (LZSOC) was used as the solid electrolyte used to form the positive electrode 10, the negative electrode 20, and the solid electrolyte layer 30. An all-solid-state battery 200 of Example 33 was obtained. In the all-solid-state battery 200 of Example 33, the same first container 41 and second container 42 as in Example 21 were used.

[Comparative Example 1]
An all-solid-state battery of Comparative Example 1 was obtained in the same manner as in Example 1, except that the coating layer 50 was not formed on the first container 41 and the second container 42 .

(Measurement of capacity retention rate after 100 cycles)
Using an electrochemical tester (manufactured by Hokuto Denko Co., Ltd.), the constant current charge-discharge test (CC-CC) of the all-solid-state batteries of Examples 1 to 33 and Comparative Example 1 was performed by the method shown below. .
Charge (CC charge) until the battery voltage reaches 2.75 V by constant current charge at a charge rate of 0.1C (current value at which charging ends in 10 hours when 1mA constant current charge is performed at 25°C). , and constant current discharge at a discharge rate of 0.1 C until the battery voltage reached 1.3 V (CC discharge). The discharge capacity (μAh) after the end of charging and discharging was detected to obtain the discharge capacity _Q1 of the first cycle.

The all-solid-state battery for which the battery capacity Q ₁ was obtained was again charged at a constant current charge of 0.1 C until the battery voltage reached 2.75 V (CC charge), and then discharged at a constant current discharge rate of 0.1 C. Then, discharge (CC discharge) was performed until the battery voltage reached 1.3V. The above charge/discharge was counted as one cycle, and 100 cycles of charge/discharge were performed. After that, the discharge capacity _Q2 after 100 cycles of charging and discharging was determined.

From the discharge capacities Q ₁ and Q ₂ thus determined, the capacity retention rate E after 100 cycles was determined using the following formula. The results are shown in Table 1 or Table 2.
E (%) = ( _Q2 / _Q1 ) x 100

As shown in Tables 1 and 2, the all-solid-state batteries of Examples 1 to 33 had higher capacity retention rates than the all-solid-state battery of Comparative Example 1. This is because, in the all-solid-state batteries of Examples 1 to 33, the coating layer 50 is formed on at least part of the inner surfaces of the first container 41 and the second container 42, so that the inner surface of the metal container 40 is a halide-based It is presumed that this is due to suppression of the reduction reaction by the solid electrolyte.

Further, from the results of the capacity retention rates of the all-solid-state batteries of Examples 3 and 21 to 25 shown in Tables 1 and 2, 90% of the surface area of the inner surfaces of the first container 41 and the second container 42 It has been confirmed that the all-solid-state battery in which the above area is covered with the covering layer 50 has a particularly high capacity retention rate.
Further, from the results of the capacity retention rates of the all-solid-state batteries of Examples 1 to 20 and Examples 26-30 shown in Tables 1 and 2, the thickness of the coating layer 50 is 0.05 μm or more. It was confirmed that the battery had a particularly high capacity retention rate.

Further, from the results of the capacity retention ratios of the all-solid-state batteries of Examples 21 and 32 shown in Table 2, when the ratio of the area covered with the coating layer 50 is 50%, the current collector layer on the negative electrode 20 It was confirmed that the all-solid-state battery in which No. 21 was installed had a high capacity retention rate. This is because the provision of the current collector layer 21 suppresses the reaction between the portion of the inner surface of the metal container 40 not covered with the coating layer 50 and the gas generated from the halide-based solid electrolyte. is estimated to be

DESCRIPTION OF SYMBOLS 10... Positive electrode, 20... Negative electrode, 21... Current collector layer, 30... Solid electrolyte layer, 40... Metal container, 41... First container, 42... Second container, 50... Coating layer, 60... Gasket, 70, 71 ... power generation element, 100, 200 ... all-solid battery.

Claims (7)

a power generating element including a positive electrode, a negative electrode, and a solid electrolyte layer interposed between the positive electrode and the negative electrode;
and a metal container that houses the power generation element,
At least one of the positive electrode, the negative electrode and the solid electrolyte layer contains a halide-based solid electrolyte represented by the following formula (1),
At least part of the inner surface of the metal container is coated with a coating layer,
The coating layer contains at least one metal selected from aluminum, nickel, titanium, and zirconium, an alloy containing the metal, and an oxide containing the metal. solid state battery.
LiaEbGcXd (1)
(In formula (1), E is at least one element selected from the group consisting of Al, Sc, Y, Zr, Hf, and lanthanides. G is OH, BO ₂ , BO ₃ , BO ₄ , B _3O6 , _B4O7 , _{CO3 , NO3 , AlO2} , _SiO3 , _SiO4 , _Si2O7 , _Si3O9 , _{Si4O11 , Si6O18 , PO3 , PO4 , P2O7} , _{P3O10 , SO3 , SO4} , _SO5 , _{S2O3 , S2O4 , S2O5 , S2O6 , S2O7 , S2O8 ,} BF ₄ , _PF6 , _BOB , (COO) ₂ , N, _AlCl4 , _CF3SO3 , _CH3COO , _CF3COO , and O. X is at least one group selected from the group consisting of F, Cl , Br, and I. 0.5≦a<6, 0<b<2, 0≦c≦6, and 0<d≦6.1.) The all-solid-state battery according to claim 1, wherein 90% or more of the surface area of the inner surface is covered with the covering layer. 3. The all-solid-state battery according to claim 1, wherein the coating layer has a thickness of 0.05 [mu]m or more. The all-solid-state battery according to any one of claims 1 to 3, wherein the negative electrode contains a negative electrode active material having an electrode potential in the range of 0.5 V or more based on the Li ⁺ /Li equilibrium potential. The all solid state battery according to claim 4, wherein the negative electrode active material contains titanium oxide. 6. The all solid state battery according to claim 5, wherein said titanium oxide is lithium titanate. The all-solid-state battery according to any one of claims 1 to 6, wherein a current collector layer is arranged between the inner surface of the metal container and the negative electrode.

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