Battery

Abstract

Provided is an essentially safe battery which has a high open-circuit voltage, a high discharge capacity, and a high coulombic efficiency, and which can be charged and discharged at room temperature. The battery exhibits an open circuit voltage of 3.0 V or more after charging, and is provided with a positive electrode containing a positive electrode active material, a negative electrode containing a negative electrode active material, and an electrolyte layer disposed between the positive electrode and the negative electrode. At least one of the positive electrode, the negative electrode, and the electrolyte layer contains a solid electrolyte represented by M [alpha] aM [beta] bM [gamma] cXd (in the formula, M [alpha] is at least one element selected from the group consisting of Li, Na, and K, M [beta] is an element having a trivalent cation, M [gamma] is an element having a tetravalent cation, X is at least one element selected from the group consisting of F, Cl, Br, and I, and a, b, c, and d satisfy 0.9 (3-x) < = a < = 1.1 (3-x), 0.9 (1-x) < = b < = 1.1 (1-x), 0.9 x < = c < = 1.1 x, 5.4 < = d < = 6.6, and 0 < x < 1).

Description

Technical Field

[0001] This invention relates to batteries. Background Technology

[0002] In recent years, with the development of portable devices such as personal computers and mobile phones, the demand for batteries that power these devices has increased significantly. In batteries used for such applications, organic electrolytes, obtained by dissolving the electrolyte in flammable organic solvents, have traditionally been used as the medium for ion movement. Batteries containing such organic electrolytes pose safety risks, such as fires and explosions. Therefore, to inherently ensure safety, all-solid-state batteries using solid electrolytes instead of organic electrolytes are being developed. In such all-solid-state batteries, the electrolyte is a non-flammable material, eliminating the risk of fire and explosion; therefore, they are inherently safe batteries.

[0003] As solid electrolytes, materials like sulfide-based solid electrolytes, which react with moisture to produce toxic hydrogen sulfide gas, are widely known. On the other hand, oxide-based solid electrolytes, which do not produce toxic gases like hydrogen sulfide, are also under extensive development. However, to improve conductivity, high-temperature sintering is required to achieve densification, which leads to the problem of high resistance due to reactions with the active material during battery manufacturing.

[0004] In recent years, halogenated solid electrolytes have been proposed. For example, Patent Document 1 (WO2023 / 013305) discloses a cathode material comprising a cathode active material and a Li-based... 6-（4-x）b (M) 1-x Al x ) b A halide solid electrolyte, represented by F6 (where M is Ti and / or Zr, 0 < x < 1, 0 < b ≤ 1.5), is capable of lithium-ion storage and release at voltages exceeding 4.3V (relative to Li). Patent Document 2 (WO2023 / 013390) discloses a solid electrolyte material using Li... 6-（4-x）b (Zr) 1-x Al x ) b F6 (where 0 < x < 1 and 0 < b ≤ 1.5) represents a solid electrolyte material and has a specified XRD peak distribution. A battery is also disclosed in which at least one of the positive electrode, negative electrode, and electrolyte layer contains this solid electrolyte material. Patent Document 3 (WO2019 / 146295) discloses a negative electrode material comprising a negative electrode active material, and Li3YCl6, Li3YBr6, and Li 2.5 Y 0.5 Zr 0.5 Cl6 or Li3YBr2Cl2I2 are solid electrolyte materials that can absorb and release lithium ions at a voltage of 0.27V or higher (relative to Li).

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: WO2023 / 013305

[0008] Patent Document 2: WO2023 / 013390

[0009] Patent Document 3: WO2019 / 146295 Summary of the Invention

[0010] However, the halide solid electrolyte disclosed in Reference 1 cannot be used for low-potential negative electrodes (graphite, metallic Li, etc.). Furthermore, in Reference 1, because sulfides are used in the electrolyte layer, toxic gases such as hydrogen sulfide may be generated. Regarding the solid electrolyte disclosed in Reference 2, its ionic conductivity is low, making it unsuitable for charge-discharge at room temperature. The all-solid-state battery disclosed in Reference 3 has a low battery voltage.

[0011] The inventors of this invention have recently discovered that by making at least one of the positive electrode, negative electrode, and electrolyte layer a halide solid electrolyte containing a specified composition, an essentially safe battery capable of charging and discharging at room temperature can be provided, exhibiting a high open-circuit voltage of 3.0V or higher, a high discharge capacity (per unit weight of positive electrode active material), and a high coulombic efficiency.

[0012] Therefore, the object of the present invention is to provide an inherently safe battery capable of being charged and discharged at room temperature, exhibiting a high open-circuit voltage of 3.0V or higher, a high discharge capacity (per unit weight of positive electrode active material), and a high coulombic efficiency.

[0013] According to the present invention, the following solution is provided.

[0014] [Option 1]

[0015] A type of battery that, after charging, has an open-circuit voltage of 3.0V or higher.

[0016] The battery is characterized by having:

[0017] Positive electrode, which contains positive electrode active material;

[0018] A negative electrode, which contains a negative electrode active material; and

[0019] An electrolyte layer is disposed between the positive electrode and the negative electrode.

[0020] At least one of the positive electrode, the negative electrode, and the electrolyte layer comprises a solid electrolyte represented by the following formula.

[0021] Mα a M β b M γ c X d

[0022] (where M) α To select at least one species from the group consisting of Li, Na, and K, M β For elements that produce trivalent cations, M γ For an element to produce a tetravalent cation, X must be at least one element selected from the group consisting of F, Cl, Br, and I, and a, b, c, and d must satisfy:

[0023] 0.9(3-x)≤a≤1.1(3-x),

[0024] 0.9(1-x)≤b≤1.1(1-x),

[0025] 0.9x≤c≤1.1x、

[0026] 5.4≤d≤6.6、and

[0027] 0 < x < 1).

[0028] [Option 2]

[0029] The battery according to Scheme 1 is characterized in that,

[0030] The positive electrode, the negative electrode, and the electrolyte layer each contain the solid electrolyte.

[0031] [Option 3]

[0032] The battery according to embodiment 1 or 2 is characterized in that,

[0033] The M α Including Li.

[0034] [Option 4]

[0035] The battery according to any one of claims 1 to 3 is characterized in that,

[0036] The M β Including Al.

[0037] [Option 5]

[0038] The battery according to any one of claims 1 to 4 is characterized in that,

[0039] The M γ Including Si and / or Ge.

[0040] [Option 6]

[0041] The battery according to any one of claims 1 to 5 is characterized in that,

[0042] X includes F.

[0043] [Option 7]

[0044] The battery according to any one of claims 1 to 6 is characterized in that,

[0045] The M α Including Li, the M β Including A1, the M γ The X includes Si, and the X includes F.

[0046] [Option 8]

[0047] The battery according to any one of claims 1 to 7 is characterized in that,

[0048] The solid electrolyte is Li a Al b Si c F d express.

[0049] [Option 9]

[0050] The battery according to any one of claims 1 to 8 is characterized in that,

[0051] The positive electrode active material comprises at least one selected from the group consisting of lithium nickel manganese oxide (LNMO), lithium nickel cobalt manganese oxide (NCM), lithium cobalt oxide (LCO), lithium nickel cobalt aluminum oxide (NCA), and lithium iron phosphate (LFP).

[0052] [Option 10]

[0053] The battery according to any one of claims 1 to 9 is characterized in that,

[0054] The negative electrode active material comprises at least one selected from the group consisting of graphite, SiO, hard carbon, Li or Li alloy, Si or Si alloy, and Sn or Sn alloy.

[0055] [Option 11]

[0056] The battery according to any one of claims 1 to 10 is characterized in that,

[0057] No part of the positive electrode, the negative electrode, or the electrolyte layer contains sulfides. Attached Figure Description

[0058] Figure 1 This is a simplified cross-sectional view showing an example of an all-solid-state battery according to the present invention.

[0059] Figure 2 This is the charge-discharge curve of the all-solid-state battery fabricated in Example 2. Detailed Implementation

[0060] Battery

[0061] The battery of the present invention is a battery that has an open-circuit voltage of 3.0V or higher after charging, typically an all-solid-state battery. However, the battery of the present invention is not limited to an all-solid-state battery, and may also be a battery that combines a solid material (solid electrolyte, etc.) and a liquid material (electrolyte, ionic liquid, etc.), or may be other types of batteries.

[0062] Figure 1 The diagram schematically illustrates an example of an all-solid-state battery 10 according to the present invention. The battery 10 includes a positive electrode 12, a negative electrode 14, and an electrolyte layer 16. The positive electrode 12 contains a positive electrode active material. The negative electrode 14 contains a negative electrode active material. The electrolyte layer 16 is disposed between the positive electrode 12 and the negative electrode 14. Furthermore, at least one of the positive electrode 12, the negative electrode 14, and the electrolyte layer 16 contains a solid electrolyte. The solid electrolyte is M... α a M β b M γ c X d (where M) α To select at least one species from the group consisting of Li, Na, and K, M β For elements that produce trivalent cations, M γ For the element to bring forth a tetravalent cation, X is selected from at least one element in the group consisting of F, Cl, Br, and I, and a, b, c, and d satisfy 0.9(3-x)≤a≤1.1(3-x), 0.9(1-x)≤b≤1.1(1-x), 0.9x≤c≤1.1x, 5.4≤d≤6.6, and 0<x<1). By making at least one of the positive electrode 12, negative electrode 14, and electrolyte layer 16 a halide solid electrolyte containing the above composition, an essentially safe battery 10 capable of charging and discharging at room temperature can be provided, exhibiting a high open-circuit voltage of 3.0V or higher, a high discharge capacity (per unit weight of positive electrode active material), and a high coulombic efficiency.

[0063] That is, the halide solid electrolyte used in this invention is a non-flammable and chemically stable material, thus providing an inherently safe battery. Furthermore, this solid electrolyte is not densified by sintering, but rather by the pressure of compression molding; therefore, high resistance does not occur during battery manufacturing due to reaction with the active material. Moreover, the solid electrolyte containing halogen elements such as F exhibits high electrochemical stability and can be combined with positive and negative electrodes that can achieve high voltages of 3.0V or higher, thus enabling the realization of a battery with high energy density. In this respect, conventional halide solid electrolytes disclosed in references 1-3, or batteries using such halide solid electrolytes, suffer from problems such as inability to be applied to low-potential negative electrodes (graphite, metallic Li, etc.), inability to charge and discharge at room temperature, and low battery voltage. However, these problems are effectively solved according to this invention.

[0064] As described above, the battery 10 of the present invention exhibits a high open-circuit voltage after charging. The open-circuit voltage after charging is 3.0V or higher, preferably 3.0 to 5.0V, and more preferably 3.1 to 4.9V. Regarding the open-circuit voltage after charging, from the viewpoint of evaluating the inherent energy (voltage) of the battery, it is preferable to use the battery voltage one hour after charging is completed, because diffusion within the electrodes slows down and stabilizes at this time. Furthermore, the battery 10 of the present invention is typically an all-solid-state battery or an all-solid-state secondary battery. For example, the battery 10 can be a lithium-ion secondary battery (typically an all-solid-state lithium-ion secondary battery), a sodium-ion secondary battery (typically an all-solid-state sodium-ion secondary battery), or a potassium-ion secondary battery (typically an all-solid-state potassium-ion secondary battery). An all-solid-state lithium-ion secondary battery is particularly preferred. Therefore, the following description of the positive electrode 12 and the negative electrode 14 is mainly based on an all-solid-state lithium-ion secondary battery; however, no application of the present invention in other batteries is excluded.

[0065] The positive electrode 12 contains a positive electrode active material. The positive electrode active material preferably contains a lithium composite oxide. Examples of lithium composite oxides include lithium nickel manganese oxide (LNMO) (typically LiNi). 0.5 Mn 1.5Lithium nickel cobalt manganese oxide (NCM) (typically Li(Ni, Co, Mn)O2), lithium cobalt oxide (LCO) (typically LiCoO2), lithium nickel cobalt aluminum oxide (NCA) (typically Li(Ni, Co, Al)O2), and lithium iron phosphate (LFP) (typically LiFePO4), as well as combinations thereof. NCM, LCO, and NCA have a layered rock salt structure. LNMO has a spinel-type structure. LFP has an olivine-type structure. Preferably, lithium composite oxides with a layered rock salt structure are used, such as NCM. The cathode 12 preferably contains, in addition to the positive electrode active material, a solid electrolyte and / or an electron conduction aid (carbon black, etc.). The positive electrode 12 in this embodiment is obtained by integrating these materials under pressure and heat. Therefore, as... Figure 1 As shown, the positive electrode 12 is typically in the form of a positive electrode layer. When the positive electrode 12 contains a solid electrolyte, the solid electrolyte described later is preferred.

[0066] The negative electrode 14 contains a negative electrode active material. Examples of negative electrode active materials include graphite, SiO, hard carbon, Li or Li alloys, Si or Si alloys, Sn or Sn alloys, and combinations thereof. These negative electrode active materials result in a low potential negative electrode 14, which helps to achieve an open-circuit voltage of 3.0V or higher after charging. Regarding the negative electrode active material, graphite, SiO, or metallic Li are preferred in terms of energy density, and graphite or SiO is particularly preferred in terms of non-flammability. From the viewpoint of improving ionic conductivity, the negative electrode 14 preferably contains a solid electrolyte in addition to the negative electrode active material. The negative electrode 14 may further contain an electron conduction aid (carbon black, etc.). The negative electrode 14 in this embodiment is obtained by integrating these materials using pressure and heating. Therefore, as Figure 1 As shown, the negative electrode 14 is typically in the form of a negative electrode layer. When the negative electrode 14 contains a solid electrolyte, it is preferable to use a solid electrolyte as described later.

[0067] Electrolyte layer 16 is an electrolyte-containing layer disposed between positive electrode 12 and negative electrode 14. Typically, electrolyte layer 16 contains a solid electrolyte, preferably composed of a solid electrolyte. In this case, electrolyte layer 16 can be said to also serve as a separator. As the solid electrolyte contained in electrolyte layer 16, a solid electrolyte described later is preferably used.

[0068] At least one of the positive electrode 12, the negative electrode 14, and the electrolyte layer 16 comprises a solid electrolyte. The solid electrolyte is represented by the following formula:

[0069] M α a M β b M γc X d

[0070] (where M) α To select at least one species from the group consisting of Li, Na, and K, M β For elements that produce trivalent cations, M γ For an element to produce a tetravalent cation, X must be at least one element selected from the group consisting of F, Cl, Br, and I, and a, b, c, and d must satisfy:

[0071] 0.9(3-x)≤a≤1.1(3-x),

[0072] 0.9(1-x)≤b≤1.1(1-x),

[0073] 0.9x≤c≤1.1x、

[0074] 5.4≤d≤6.6、and

[0075] 0 < x < 1).

[0076] The solid electrolyte exhibits high ionic conductivity (e.g., lithium-ion conductivity). Furthermore, it is non-flammable and chemically stable, and does not produce hydrogen sulfide gas, thus enabling an inherently safe battery 10. However, it is not necessary for all of the positive electrode 12, negative electrode 14, and electrolyte layer 16 to contain the aforementioned solid electrolyte; at least one of them may contain it.

[0077] The meaning of the above composition formula is explained below. First, typically, the above solid electrolyte is a mixture containing M α M β and compounds of X (e.g., Li3AlF6) and compounds of M α 2M γ The solid electrolyte is obtained by mixing compounds represented by X6 (e.g., Li2SiF6). For example, this solid electrolyte is obtained by mixing M... α 3M β X6 and M α 2M γ Obtained by mixing X6. M α 3M β X6 and M α 2M γ When X6 is mixed in a mass ratio of (1-x):x (where 0 < x < 1), the composition of this solid electrolyte is expressed as M. α 3-x M β 1-x M γ xX6 represents the value. If we consider measurement errors and other factors to give this composition a tolerance range of ±0.1 (i.e., a range from the lower limit obtained by multiplying by 0.9 to the upper limit obtained by multiplying by 1.1), then M... α M β M γ The mass ratio of X, a:b:c:d, is as described above: 0.9(3-x)≤a≤1.1(3-x), 0.9(1-x)≤b≤1.1(1-x), 0.9x≤c≤1.1x, and 5.4≤d≤6.6. That is, within these numerical ranges, it can be said that the desired performance of the solid electrolyte (e.g., high ionic conductivity) can be obtained equally. In the above composition formula, it is preferable to satisfy 0.05≤x≤0.8, more preferably 0.05≤x≤0.6. This further improves lithium-ion conductivity and plasma conductivity.

[0078] M α It is selected from at least one of the group consisting of Li, Na, and K. In the case of lithium-ion secondary batteries, M α Li is preferred, and M is more preferred. α In the case of a Li-sodium ion secondary battery, M α Preferred components include Na, more preferably M. α In the case of a Na+ potassium ion secondary battery, M α K is preferred, and M is more preferred. α For K. M β The element is one that generates a trivalent cation. Examples of elements that generate trivalent cations include Al, Ga, In, Sc, Y, and La, with Al being the most preferred. Therefore, M β Preferably, it includes Al. M γ The element is one that brings forth a tetravalent cation. Examples of elements that bring forth a tetravalent cation include Si, Ge, and Sn, with Si and / or Ge being preferred, and Si being more preferred. Therefore, M γ Preferably, it includes Si and / or Ge, more preferably Si. X is at least one selected from the group consisting of F, Cl, Br, and I, preferably F. Therefore, X preferably includes F. Particularly preferred is M. α Including Li, M β Including Al, M γ Including Si, X includes F. Therefore, Li is particularly preferred. a Al b Si c F d The solid electrolyte described has high lithium-ion conductivity. With such a composition, it is possible to manufacture solid electrolytes with high lithium-ion conductivity more reliably.

[0079] The above-mentioned solid electrolyte can be obtained by (i) containing Mα M β and compounds of X (e.g., Li3AlF6) and compounds of M α 2M γ A mixture of compounds represented by X6 (e.g., Li2SiF6), or (ii) compounds derived from M β Compounds composed of X (e.g., AlF3), and compounds composed of M α and compounds composed of X (e.g., LiF) and M α 2M γ The mixture of X6 (e.g., Li2SiF6) is mechanically milled to produce a solid electrolyte with high ionic conductivity. The reason for this is not clear, but one possible explanation is that mechanical milling allows for the production of solid electrolytes containing M... α In the crystal structure of (for example, Li), M β (e.g., Al) and M γ (e.g., Si) Mixture (e.g., Si) 4+ Solid solution in Al 3+ ).

[0080] In confirming whether the unknown solid electrolyte is the aforementioned solid electrolyte, a chemical analysis is performed on the unknown solid electrolyte to confirm whether the constituent element is M. α M β M γ Alternatively, X can be used. Furthermore, when confirming whether an unknown solid electrolyte has the above composition, for example, regarding Li, Al, and Si, quantification can be performed using an ICP-luminescence spectrophotometer. Regarding F, quantification can be performed using ion chromatography. The solid electrolyte contains M, excluding Al. β In this case, appropriately select elements M. β A quantitative measurement method can be used.

[0081] The solid electrolyte used in this invention can be mixed with other substances (which may include X such as Li) to serve as an electrolyte material. In this case, the solid electrolyte is preferably the component with the largest mass percentage among the components contained in the electrolyte material, i.e., the main component. The mass percentage of the main component in the electrolyte material is preferably 50% by weight or more, more preferably 60% by weight or more, and even more preferably 70% by weight or more.

[0082] As described above, in the battery 10 of the present invention, the positive electrode 12, the negative electrode 14, and the electrolyte layer 16 can be made of sulfide-free materials. That is, preferably, no part of the positive electrode 12, the negative electrode 14, and the electrolyte layer 16 contains sulfides. Accordingly, toxic gases such as hydrogen sulfide are not produced, and an inherently safe battery 10 is provided.

[0083] The battery 10 preferably also includes a positive current collector 18 and a negative current collector 20. The positive current collector 18 is preferably disposed on the side of the positive electrode 12 opposite to the electrolyte layer 16, and the negative current collector 20 is preferably disposed on the side of the negative electrode 14 opposite to the electrolyte layer 16. Examples of materials constituting the positive current collector 18 and the negative current collector 20 include: aluminum (Al), copper (Cu), titanium (Ti), nickel (Ni), stainless steel (SUS), carbon, platinum (Pt), platinum (Pt) / palladium (Pd), gold (Au), silver (Ag), ITO (indium-tin oxide film), etc.

[0084] The container 22 can be any container capable of storing a single battery 10 or a battery stack consisting of more than 10 batteries connected in series or in parallel; there are no particular limitations. In particular, when the battery 10 is an all-solid-state battery, since there is no concern about electrolyte leakage, the container 22 can adopt a simpler container form. For example, it can adopt a chip form for mounting in electronic circuits or a laminated single-cell form (e.g., a multilayer product of aluminum (Al) / polypropylene (PP)) for thin and wide space applications.

[0085] Methods for manufacturing solid electrolytes

[0086] As an example of a preferred manufacturing method for the aforementioned solid electrolyte, the following describes a method for mixing Li3AlF6 (hereinafter referred to as LAF) and Li2SiF6 (hereinafter referred to as LSF) and performing mechanical milling.

[0087] First, prepare LAF powder. For example, weigh and mix commercially available LiF (lithium fluoride) powder and commercially available AlF3 (aluminum fluoride) powder at a molar ratio of LiF:AlF3 = 3:1. Next, heat the resulting mixture at a high temperature (e.g., 900°C) and then pulverize it to obtain LAF powder. LAF powder can also be prepared using other methods.

[0088] On the other hand, prepare the LSF powder. Commercially available LSF powder can be used, but it can also be prepared using known methods.

[0089] Next, the LAF powder and LSF powder are mixed to obtain a mixed powder. The mass percentage of LSF in this mixed powder is greater than 0 mol% and less than 100 mol% of the total mass of LAF and LSF, preferably 5 to 80 mol%, more preferably 5 to 60 mol%.

[0090] By mechanically grinding the resulting mixed powder, a powder suitable for use as the solid electrolyte of this invention can be obtained. In one example of mechanical grinding, a planetary ball mill is used. In a planetary ball mill, the jar rotates on its own axis while the worktable carrying the jar revolves around it, thus generating very high impact energy. However, other types of pulverizers can also be used for mechanical grinding. Mechanical grinding can be performed at room temperature; however, conditions such as temperature can be appropriately varied.

[0091] Example

[0092] The invention will be further illustrated by the following examples. However, the invention is not limited to these examples.

[0093] Example 1 (Compare)

[0094] (1) Preparation of LYC solid electrolyte powder

[0095] In a glove box or dry room with a dew point below -40°C, commercially available LiCl powder and commercially available YCl3 powder were weighed and mixed at a molar ratio of LiCl:YCl3 = 3:1, and mechanically ground using a planetary ball mill to obtain LYC solid electrolyte powder with the composition of Li3Y1Cl6.

[0096] (2) Fabrication of positive electrode sheet

[0097] LYC solid electrolyte powder, lithium nickel cobalt manganese oxide (NCM) powder (as the positive electrode active material), and carbon powder (carbon black) (as a conductive additive) were weighed and mixed at a volume ratio of LYC:NCM:carbon = 50:50:2 to obtain a positive electrode blending powder. Organic binders and organic solvents were added to the obtained positive electrode blending powder, and the mixture was kneaded. Positive electrode sheets were then fabricated using a scraper method.

[0098] (3) Fabrication of negative electrode sheet

[0099] LYC solid electrolyte powder, graphite powder as the negative electrode active material, and carbon powder (carbon black) as a conductive additive were weighed and mixed at a volume ratio of LYC:graphite:carbon = 50:50:2 to obtain a negative electrode blending powder. Organic binder and organic solvent were added to the obtained negative electrode blending powder, and the mixture was kneaded and then used to fabricate negative electrode sheets using a scraper method.

[0100] (4) Fabrication of solid electrolyte sheets

[0101] Organic binders and organic solvents are added to LYC solid electrolyte powder, and the mixture is kneaded and then used to produce solid electrolyte sheets using a scraper method.

[0102] (5) Fabrication of all-solid-state batteries

[0103] The positive electrode sheet, negative electrode sheet, and solid electrolyte sheet are punched using a punching machine to obtain positive electrode sheets, negative electrode sheets, and solid electrolyte sheets with a diameter of 10mm. The positive electrode sheet, solid electrolyte sheet, and negative electrode sheet are then placed in this order into a 10mm inner diameter mold made of PEEK resin, and clamped in from the top and bottom by a pair of stainless steel metal punches. In this state, uniaxial pressing is performed at a pressure of 150MPa to stack and integrate them, resulting in an all-solid-state battery.

[0104] (6) Evaluation of all-solid-state batteries (charge and discharge test)

[0105] Connect wires to the top and bottom of a pair of metal punches, and conduct a charge-discharge test of the all-solid-state battery at room temperature as follows. First, charge the all-solid-state battery under the following conditions: charging termination voltage: 4.15V, CC charging current: 0.1C, CV charging current: 0.01C. That is, charge at a constant current (CC) rate of 0.1C until the voltage reaches 4.15V, and then charge at a constant voltage (CV) rate until the current reaches 0.01C. The battery voltage (open circuit voltage) was measured one hour after charging was completed, and the result was 3.92V. For the all-solid-state battery charged in this way, discharge was performed under the following conditions: discharging termination voltage: 2.00V, CC discharge current: 0.1C, CV discharge current: 0.01C. That is, discharge at a constant current (CC) rate of 0.1C until the voltage reaches 2.00V, and then discharge at a constant voltage (CV) rate until the current reaches 0.01C. The obtained discharge capacity was 58 mAh / g per 1g of positive electrode active material, and the coulombic efficiency was 56%. These results are shown in Table 1.

[0106] Example 2

[0107] LAF-LSF solid electrolyte powder was prepared to replace LYC solid electrolyte powder, and its evaluation and use were carried out. Otherwise, the preparation and evaluation of all-solid-state batteries were performed in the same manner as in Example 1. The results are shown in Table 1 and... Figure 2 As shown.

[0108] (Preparation of LAF-LSF solid electrolyte powder)

[0109] LAF-LSF solid electrolyte powder was prepared as follows in a glove box or dry room with a dew point below -40°C. First, commercially available LiF powder and commercially available AlF3 powder were weighed and mixed at a molar ratio of LiF:AlF3 = 3:1. After treatment under an Ar atmosphere at 900°C, the mixture was pulverized using a mortar and pestle to obtain LAF powder with a Li3AlF6 composition. The obtained LAF powder and commercially available Li2SiF6 powder were weighed and mixed at a molar ratio of LAF(Li3AlF6):Li2SiF6 = 8:2. The mixture was then mechanically ground using a planetary ball mill to obtain LAF powder with a Li3AlF6 composition. 2.8 Al 0.8 Si 0.2 F 6.0 The composition of LAF-LSF solid electrolyte powder.

[0110] (Determination of ionic conductivity)

[0111] LAF-LSF solid electrolyte powder was placed in a mold equipped with a PEEK (polyetheretherketone) resin sleeve and stainless steel upper and lower punches, and uniaxially pressed under pressure of 400 MPa. Wires were connected to the upper and lower punches, and impedance measurements were performed at room temperature to calculate the ionic conductivity. The results showed that the ionic conductivity of the LAF-LSF solid electrolyte at room temperature was 5 × 10⁻⁶. -6 S / cm or higher.

[0112] Example 3

[0113] SiO powder was used as the negative electrode active material. Otherwise, the all-solid-state battery was fabricated and evaluated in the same manner as in Example 2. The results are shown in Table 1.

[0114] Example 4

[0115] Lithium nickel manganese oxide (LNMO) powder was used as the positive electrode active material. Otherwise, the all-solid-state battery was fabricated and evaluated in the same manner as in Example 2. The results are shown in Table 1.

[0116] Example 5

[0117] Lithium iron phosphate (LFP) powder was used as the positive electrode active material. Otherwise, the all-solid-state battery was fabricated and evaluated in the same manner as in Example 2. The results are shown in Table 1.

[0118] Table 1

[0119]

Claims

1. A battery that, after charging, has an open-circuit voltage of 3.0V or higher. The battery is characterized by having: Positive electrode, which contains positive electrode active material; A negative electrode, which contains a negative electrode active material; and An electrolyte layer is disposed between the positive electrode and the negative electrode. At least one of the positive electrode, the negative electrode, and the electrolyte layer comprises a solid electrolyte represented by the following formula. M α a M β b M γ c X d In the formula, M α To select at least one species from the group consisting of Li, Na, and K, M β For elements that produce trivalent cations, M γ For an element to produce a tetravalent cation, X must be at least one element selected from the group consisting of F, Cl, Br, and I, and a, b, c, and d must satisfy: 0.9(3-x)≤a≤1.1(3-x), 0.9(1-x)≤b≤1.1(1-x), 0.9x≤c≤1.1x、 5.4≤d≤6.6、and 0＜x＜1。 2. The battery according to claim 1, characterized in that, The positive electrode, the negative electrode, and the electrolyte layer each contain the solid electrolyte.

3. The battery according to claim 1 or 2, characterized in that, The M α Including Li.

4. The battery according to claim 1 or 2, characterized in that, The M β Including Al.

5. The battery according to claim 1 or 2, characterized in that, The M γ Including Si and / or Ge.

6. The battery according to claim 1 or 2, characterized in that, X includes F.

7. The battery according to claim 1 or 2, characterized in that, The M α Including Li, the M β Including A1, the M γ The X includes Si, and the X includes F.

8. The battery according to claim 1 or 2, characterized in that, The solid electrolyte is Li a Al b Si c F d express.

9. The battery according to claim 1 or 2, characterized in that, The positive electrode active material comprises at least one selected from the group consisting of lithium nickel manganese oxide (LNMO), lithium nickel cobalt manganese oxide (NCM), lithium cobalt oxide (LCO), lithium nickel cobalt aluminum oxide (NCA), and lithium iron phosphate (LFP).

10. The battery according to claim 1 or 2, characterized in that, The negative electrode active material comprises at least one selected from the group consisting of graphite, SiO, hard carbon, Li or Li alloy, Si or Si alloy, and Sn or Sn alloy.

11. The battery according to claim 1 or 2, characterized in that, No part of the positive electrode, the negative electrode, or the electrolyte layer contains sulfides.

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