SOLID ELECTROLYTE, SOLID ELECTROLYTE LAYER AND SOLID ELECTROLYTE BATTERY

Abstract

A solid electrolyte (10) of the present invention comprises: Li a A b E c (SO4) d J e X r H h ... (1), where in formula (1) A is at least one element selected from alkaline earth metals and alkali metals other than Li, E is at least one element selected from the group consisting of Al, Ga, In, Sc, Y, Ti, Zr, Hf and lanthanides, J is at least one group selected from the group consisting of OH, BO2, BO3, BO4, B3O6, B4O7, CO3, NO3, AlO2, SiO3, SiO4, Si2O7, Si3O9, Si4O 11 , Si6O 18 , PO3, PO4, P2O7, P3O 10, SO3, SO5, S2O3, S2O4, S2O5, S2O6, S2O7, S2O8, BF4, PF6, BOB, (COO)2, N, AlCl4, CF3SO3, CH3COO, CF3COO, OOC-(CH2)2-COO, OOC-CH2-COO, OOC-CH(OH)-CH(OH)-COO, OOC-CH(OH)-CH2-COO, C6H5SO3, OOC-CH=CH-COO, OOC-CH=CH-COO, C(OH)(CH2COOH)2COO, AsO4, BiO4, CrO4, MnO4, PtF6, PtCl6, PtBr6, PtI6, SbO4, SeO4, TeO4, HCOO, and O, X, where at least one element is selected from the group consisting of F, Cl, Br and I, 0.5 ≤ a < 6, 0 ≤ b < 6, 0 < c < 2, 0.1 < d ≤ 6.0, 0 < e ≤ 6.0, 0 < f ≤ 6.1, and 0 ≤ h ≤ 0.2 are satisfied, and a peak is observed at a diffraction angle 2θ = 22.3 °± 1.0° in an X-ray diffraction pattern in which Cu-Kα is used as the line source.

Description

TECHNICAL FIELD

[0001] The present invention relates to a solid electrolyte, a solid electrolyte layer and a solid electrolyte battery.

[0002] Priority is claimed by Japanese Patent Application No. 2022-038447, filed on March 11, 2022, the contents of which are incorporated herein by reference. BACKGROUND

[0003] In recent years, electronics technology has undergone remarkable development, with portable electronic devices becoming smaller, lighter, thinner, and more multifunctional. Accordingly, there is a strong demand for batteries that serve as power sources for electronic devices and are smaller, lighter, thinner, and more reliable. Solid electrolyte batteries, which use a solid electrolyte as the electrolyte, have attracted considerable attention. Solid electrolytes include oxide solid electrolytes, sulfide solid electrolytes, complex hydride solid electrolytes, and halide solid electrolytes.

[0004] For example, Non-Patent Document 1 describes that Li3ScCl6, which is a halide solid electrolyte, has an ionic conductivity of 3 mS / cm and a potential window of 0.91 V (V vs. Li / Li + ) on the reduction side. [Citation list][Non-patent document]

[0005] [Non-patent document 1] Jianwen Liang et al., Journal of American Chemical Society 2020, 142, 7012-7022 SUMMARY OF THE INVENTIONTechnical Problem

[0006] Halide solid electrolytes are said to have higher ionic conductivity than oxide solid electrolytes, sulfide solid electrolytes, complex hydride solid electrolytes, and the like. Although Li3ScCl6 described in Non-Patent Document 1 has high ionic conductivity (3 mS / cm), it has various limitations, and the properties described in Non-Patent Document 1 may not be expressed as they are, or other substances may need to be selected. Therefore, a configuration that can relatively improve ionic conductivity in solid electrolytes with similar structures is required.

[0007] The present invention has been made in consideration of the problems described above, and an object of the present invention is to provide a solid electrolyte, a solid electrolyte layer and a solid electrolyte battery capable of improving ionic conductivity. Solution to the problem

[0008] The present invention provides the following means for solving the problems described above. (1) A solid electrolyte according to a first aspect comprises Li a A b E c (SO4) d J e X r H h... (1). In formula (1), A is at least one element selected from alkaline earth metals and alkali metals except Li, E is at least one element selected from the group consisting of Al, Ga, In, Sc, Y, Ti, Zr, Hf and lanthanides, J is at least one group selected from the group consisting of OH, BO2, BO3, BO4, B3O6, B4O7, CO3, NO3, AlO2, SiO3, SiO4, Si2O7, Si3O9, Si4O 11 , Si6O 18 , PO3, PO4, P2O7, P3O 10, SO3, SO5, S2O3, S2O4, S2O5, S2O6, S2O7, S2O8, BF4, PF6, BOB, (COO)2, N, AlCl4, CF3SO3, CH3COO, CF3COO, OOC-(CH2)2-COO, OOC-CH2-COO, OOC-CH(OH)-CH(OH)-COO, OOC-CH(OH)-CH2-COO, C6H5SO3, OOC-CH=CH-COO, OOC-CH=CH-COO, C(OH)(CH2COOH)2COO, AsO4, BiO4, CrO4, MnO4, PtF6, PtCl6, PtBr6, PtI6, SbO4, SeO4, TeO4, HCOO, and O, and X is at least one element selected from the group consisting of F, Cl, Br, and I. Furthermore, in formula (1), 0.5 ≤ a < 6.0 ≤ b < 6.0 < c < 2.0, 1 < d ≤ 6.0, 0 < e ≤ 6.0, 0 < f ≤ 6.1, and 0 ≤ h ≤ 0.2 are satisfied. Furthermore, in the solid electrolyte according to the first aspect, a peak is observed at a diffraction angle 2θ = 22.3° ± 1.0° in an X-ray diffraction pattern using Cu-Kα as a line source. (2) In the solid electrolyte according to the above-described aspect, a peak can be observed at a diffraction angle 20 = 36.4 ° ± 1.0 ° in the X-ray diffraction pattern in which Cu-Kα is used as a line source. (3) In the solid electrolyte according to the above-described aspect, a peak at 170 ± 0.5 eV and 532 ± 0.5 eV can be observed in the X-ray photoelectron spectroscopy measurement. (4) In the solid electrolyte according to the above-described aspect, an ionic conductivity at 25°C may be 1 mS / cm or more. (5) A solid electrolyte layer according to a second aspect includes: the solid electrolyte according to the above-described aspect. (6) A solid electrolyte battery according to a third aspect includes: a negative electrode; a positive electrode; and a solid electrolyte layer disposed between the negative electrode and the positive electrode and containing a solid electrolyte. At least one or more of the negative electrode, the positive electrode, and the solid electrolyte layer contain the solid electrolyte according to the above-described aspect. (7) A solid electrolyte battery according to a fourth aspect includes: a negative electrode; a positive electrode; and the solid electrolyte layer according to the above-described aspect between the negative electrode and the positive electrode. Advantageous effects of the invention

[0009] The solid electrolyte according to the above-described aspect can improve ionic conductivity. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 shows X-ray diffraction results of a solid electrolyte according to the present embodiment. Fig. Figure 2 shows X-ray diffraction results of the solid electrolyte containing a compound of formula (1). Fig. 3A is a graph showing the results of X-ray photoelectron spectroscopy measurement of the solid electrolyte according to the present embodiment, in which a region where a peak derived from O1s appears is enlarged. Fig.3B is a graph showing the results of X-ray photoelectron spectroscopy measurement of the solid electrolyte according to the present embodiment, in which a region where a peak derived from S2p appears is enlarged. Fig. 4 is a schematic cross-sectional view of a solid electrolyte battery 100 according to the present embodiment. Fig. Figure 5 shows X-ray diffraction results of Comparative Example 4. Fig. Figure 6 shows the charge / discharge curves of Example 4 and Comparative Examples 3 and 4. DESCRIPTION OF EMBODIMENTS

[0010] Hereinafter, the present embodiment will be described in detail with reference to the accompanying drawings. In the drawings used in the following description, a part that becomes a feature of the present invention is sometimes enlarged for convenience in order to easily understand the feature, and the dimensional proportions of individual components and the like are sometimes different from the actual ones. The materials, dimensions, and the like exemplified in the following description are merely examples, and the present invention is not limited thereto and can be implemented by appropriate modifications within a range that does not change the gist. “Solid electrolyte”

[0011] A solid electrolyte is a material that can transfer ions through the application of an external electric field. The high ionic conductivity of a solid electrolyte facilitates the smooth exchange of ions in a solid electrolyte battery, resulting in lower internal resistance.

[0012] A solid electrolyte contains a halide solid electrolyte, represented by Li a A b E c (SO4) d J e X r H h ... (1). The solid electrolyte can contain either a material obtained from a raw material powder or the compound represented by the above formula (1). The material obtained from a raw material powder is, for example, Li2SO4.

[0013] The solid electrolyte may be in the form of a powder (particle) or a sintered body obtained by sintering a powder. In addition, the solid electrolyte may also be a molded body obtained by compressing and molding a powder, a molded body obtained by molding a mixture of a powder and a binder, and a coating film obtained by applying a coating material containing a powder, a binder, and a solvent, followed by heating the coating material to remove the solvent. Furthermore, the main structure of the solid electrolyte may be amorphous or crystalline.

[0014] In formula (1), Li is a lithium ion. α satisfies 0.5 ≤ α < 6, preferably 2.0 ≤ α < 4.0, and more preferably 2.5 ≤ α < 3.5. When E is Zr or Hf, α is preferably 1.0 ≤ α < 3.0, and particularly preferably 1.5 ≤ α < 2.5. In the compound represented by formula (1), when α is 0.5 ≤ α < 6, the Li content in the compound is appropriate, and the ionic conductivity of a solid electrolyte layer 10 is high.

[0015] In formula (1), A is at least one element selected from alkaline earth metals and alkali metals except Li. A substitutes for part of the Li ions. For example, A is Na or Ca. When A is Na or Ca, the potential window on the reduction side of the solid electrolyte is wider. b satisfies 0 ≤ 0 < 6. Furthermore, a + b satisfies 0.5 ≤ a + b < 6.

[0016] In formula (1), E is an essential component and at least one element selected from the group consisting of Al, Ga, In, Sc, Y, Ti, Zr, Hf, and lanthanides (La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu). E preferably includes Al, Sc, Y, Zr, Hf, and La, and more preferably Zr and Y. E improves the ionic conductivity of the solid electrolyte. C is 0 < b < 2. Since the effect of incorporating E is more effective in this case, c is preferably 0.6 ≤ c. In addition, E is also an element that forms a framework of the solid electrolyte. c is more preferably c ≤ 1.

[0017] In formula (1), SO4 is sulfate. d satisfies 0.1 < d ≤ 6.0, preferably satisfies 0.2 ≤ d ≤ 4.0, and more preferably satisfies 0.4 ≤ d ≤ 2.5. When the solid electrolyte contains sulfate, the potential window on the reduction side of the solid electrolyte is wider, and it is less likely to be reduced.

[0018] In formula (1), J is, for example, at least one group selected from the group consisting of OH, BO2, BO3, BO4, B3O6, B4O7, CO3, NO3, AlO2, SiO3, SiO4, Si2O7, Si3O9, Si4O 11 , Si6O 18 , PO3, PO4, P2O7, P3O 10 , SO3, SO5, S2O3, S2O4, S2O5, S2O6, S2O7, S2O8, BF4, PF6, bisoxalate borate (BOB), (COO)2, N, AlCl4, CF3SO3, CH3COO, CF3COO, succinate (OOC-(CH2)2-COO), malonate (OOC-CH2-COO), tartrate (OOC-CH(OH)-CH(OH)-COO), malate (OOC-CH(OH)-CH2-COO), benzenesulfonate (C6H5SO3), fumarate (OOC-CH=CH-COO), maleate (OOC-CH=CH-COO), citrate (C(OH)(CH2COOH)2COO), AsO4, BiO4, CrO4, MnO4, PtF6, PtCl6, PtBr6, PtI6, SbO4, SeO4, TeO4, HCOO, and O. J is preferably at least one group selected from the group consisting of OH, SO4, CH3COO, CF3COO, HCOO and O. J replaces a part of the sulfate.

[0019] e satisfies 0 ≤ e ≤ 6. e is preferably 0.5 ≤ e because the effect of a wider potential window on the reduction side is more significant due to the inclusion of J. e is preferably e ≤ 3 so that the ionic conductivity of the solid electrolyte does not decrease due to excessive J content. Furthermore, d + e satisfies 0.1 < d ≤ 6.0.

[0020] X is at least one or more elements selected from the group consisting of F, Cl, Br and I. X is preferably at least one or more elements selected from the group consisting of Cl, Br and I in order to increase the ionic conductivity of the solid electrolyte, and preferably includes Br and / or I, and more preferably I. When X includes F, X preferably includes F and two or more elements selected from the group consisting of Cl, Br and I, since X is a solid electrolyte with a high ionic conductivity.

[0021] When X is F, the solid electrolyte has sufficiently high ionic conductivity and excellent oxidation resistance. When X is Cl, the solid electrolyte has high ionic conductivity and a good balance between oxidation resistance and reduction resistance. When X is Br, the solid electrolyte has sufficiently high ionic conductivity and a good balance between oxidation resistance and reduction resistance. When X is I, the solid electrolyte has high ionic conductivity.

[0022] f satisfies 0 < f ≤ 6.1. d is preferably 1 ≤ f. When f 1 ≤ d, the strength of a pellet is higher when the solid electrolyte is formed into a pellet shape by compression molding. Furthermore, the ionic conductivity of the solid electrolyte is high when f 1 ≤ f. Furthermore, f is preferably f ≤ 5 so that the potential window of the solid electrolyte is not narrowed by a lack of sulfate due to excessive X content.

[0023] In formula (1), H is hydrogen. h satisfies 0 ≤ h ≤ 0.2.

[0024] Solid electrolytes include Li2ZrSO4Cl4, Li3YSO4Cl4, Li3ScSO4Cl4 and Li3InSO4Cl4.

[0025] Fig. Figure 1 shows X-ray diffraction (XRD) results of a solid electrolyte according to the present embodiment. The vertical axis in Fig. 1 is the intensity and the horizontal axis is 2θ. X-ray diffraction is performed using a Cu-α source.

[0026] The Fig. The X-ray diffraction pattern shown in Figure 1 is one obtained by removing the background data of the polyimide tape from the measurement results. Fig. Figure 1 shows the X-ray diffraction results of Example 4, which is described below. As in Fig.As shown in Figure 1, in the solid electrolyte according to the present embodiment, a peak at a diffraction angle 20 = 22.3° ± 1.0° is observed in an X-ray diffraction pattern in which Cu-Kα is used as a line source. Furthermore, in the solid electrolyte according to the present embodiment, a peak at a diffraction angle 20 = 36.4° ± 1.0° can be observed in the X-ray diffraction pattern in which Cu-Kα is used as a line source.

[0027] These peaks are believed to originate from Li2SO4, a raw material used in the preparation of the compound of formula (1). The peak occurring at the diffraction angle 2θ = 22.3°± 1.0° is a first peak exhibiting the highest intensity in the X-ray diffraction pattern of Li2SO4.

[0028] The peak appearing at the diffraction angle 2θ = 36.4 °± 1.0° is a peak that has a relatively high intensity in the X-ray diffraction pattern of Li2SO4.

[0029] These peaks are peaks that disappear when the raw materials are allowed to react sufficiently with each other. Fig. Figure 2 shows X-ray diffraction results of the solid electrolyte containing the compound of formula (1). Fig. The X-ray diffraction patterns shown in Figure 2 are measured raw data from which the background data of the polyimide tape were not removed. The further one moves from the front of the paper to the back, the more advanced the reaction between the raw materials is. As shown in Fig. As shown in Figure 2, the peaks appearing at the diffraction angle 20 = 22.3°±1.0° and the diffraction angle 20 = 36.4°±1.0° disappear as the reaction between the raw materials proceeds. Therefore, the fact that these peaks are observed in the solid electrolyte according to the present embodiment suggests that some unreacted raw material powder (LiSO4) remains.

[0030] Fig.3A and Fig. 3B are graphs showing X-ray photoelectron spectroscopy measurement results of the solid electrolyte according to the present embodiment, in which a region where a peak appears is enlarged. In the solid electrolyte according to the present embodiment, for example, peaks at 170 ± 0.5 eV and 532 ± 0.5 eV are observed. The peak at 170 ± 0.5 eV is a sulfur peak derived from S2p, which is identified when there is a structure in which sulfur is bonded to oxygen, and the peak at 532 ± 0.5 eV is an oxygen peak derived from O1s, which is identified when there is a structure in which sulfur is bonded to oxygen. In other words, it can be said that the solid electrolyte has a part with an SO4 structure, and this structure is considered to be derived from an unreacted raw material powder (LiSO4).

[0031] The solid electrolyte according to the present embodiment exhibits specific peaks observed by X-ray diffraction as described above, and it has high ionic conductivity. For example, the ionic conductivity of the solid electrolyte according to the present embodiment is 1 mS / cm or more. It is not clear why the ionic conductivity increases when the solid electrolyte exhibits specific peaks in X-ray diffraction, but it is suspected that this is because the remaining crystalline substance LiSO4 becomes a starting point for the formation of a microstructure in the solid electrolyte that has flow paths through which Li ions can be conducted. “Solid electrolyte battery”

[0032] Fig. 4 is a schematic cross-sectional view of a solid electrolyte battery 100 according to the present embodiment. Fig.The solid electrolyte battery 100 shown in Figure 4 includes a power generation element 40 and an outer body 50. The outer body 50 covers the periphery of the power generation element 40. The power generation element 40 is connected to the outside via a pair of interconnected terminals 60 and 62. In Fig. 1 shows a laminated battery, but a wound battery can also be used. The solid electrolyte battery 100 is used, for example, as a laminate battery, square battery, cylindrical battery, coin battery, and button battery. <stromerzeugungselement>

[0033] The power generation element 40 includes the solid electrolyte layer 10, a positive electrode 20, and a negative electrode 30. The power generation element 40 performs charging or discharging by exchanging ions across the solid electrolyte layer 10 between the positive electrode 20 and the negative electrode 30 and exchanging electrons through an external circuit. (solid electrolyte layer)

[0034] The solid electrolyte layer 10 is arranged between the positive electrode 20 and the negative electrode 30. The solid electrolyte layer 10 contains a solid electrolyte capable of transferring ions through an externally applied voltage. Solid electrolytes, for example, conduct lithium ions and prevent the transfer of electrons.

[0035] The solid electrolyte layer 10 is, for example, a halide solid electrolyte. The solid electrolyte layer 10 contains, for example, the solid electrolyte described above. If the positive electrode 20 or the negative electrode 30 contains the solid electrolyte described above, the solid electrolyte contained in the solid electrolyte layer 10 does not need to be the one described above. (Positive electrode)

[0036] As in Fig. 4, the positive electrode 20 has a plate-shaped (foil-shaped) positive electrode current collector 22 and a positive electrode mixture layer 24. The positive electrode mixture layer 24 comes into contact with at least one surface of the positive electrode current collector 22.

[0037] The positive electrode current collector 22 can be an electron-conducting material that is resistant to oxidation and corrosion during charging. The positive electrode current collector 22 is, for example, a metal such as aluminum, stainless steel, nickel, or titanium, or a conductive resin. The positive electrode current collector 22 can be in powder form, as a foil, stamped, or expanded.

[0038] The positive electrode mixture layer 24 contains a positive electrode active material and optionally a solid electrolyte, a binder and a conductive aid.

[0039] The positive electrode active material is not particularly limited as long as it is capable of promoting lithium ion occlusion / release and insertion / deportion (intercalation / deintercalation). Positive electrode active materials used in known solid electrolyte batteries can be used. Examples of positive electrode active materials include lithium-containing metal oxides and lithium-containing metal phosphorus oxides.

[0040] Lithium-containing metal oxides include, for example, lithium cobaltate (LiCoO2), lithium nickelate (LiNiO2), lithium manganese spinel (LiMn2O4) and compound metal oxides represented by the general formula: LiNi x Co y Mn z O2 (x + y + z = 1), lithium vanadium compounds (LiVOPO4, Li3V2(PO4)3), olivine-type LiMPO4 (where M denotes at least one of Co, Ni, Mn and Fe) and lithium titanate (Li4Ti5O 12 ).

[0041] In addition, the positive electrode active material can also be lithium-free. Examples of positive electrode active materials include lithium-free metal oxides (such as MnO2 and V2O5), lithium-free metal sulfides (such as MoS2), and lithium-free fluorides (such as FeF3 and VF3). When using a positive electrode active material that does not contain lithium, a negative electrode is pre-doped with lithium ions or a negative electrode containing lithium ions is used.

[0042] A solid electrolyte contained in the positive electrode 20 is, for example, the solid electrolyte described above. The solid electrolyte contained in the positive electrode 20 may be a halide solid electrolyte other than the solid electrolyte described above.

[0043] The amount of a solid electrolyte in the positive electrode mixture layer 24 is not particularly limited, but is preferably 1 mass% to 50 mass%, and more preferably 5 mass% to 30 mass%, based on the total mass of a positive electrode active material, the solid electrolyte, a conductive assistant, and a binder.

[0044] A binder binds a positive electrode active material, a solid electrolyte, and a conductive auxiliary agent together in the positive electrode mixture layer 24 and also firmly bonds the positive electrode mixture layer 24 to the positive electrode current collector 22. The positive electrode mixture layer 24 preferably contains a binder. The binder is preferably oxidation-resistant and has favorable adhesion properties.

[0045] Examples of binders used in the positive electrode mixture layer 24 include polyvinylidene fluoride (PVDF) or copolymers thereof, polytetrafluoroethylene (PTFE), polyamide (PA), polyimide (PI), polyamideimide (PAI), polybenzimidazole (PBI), polyethersulfone (PES), polyacrylic acid (PA) and its copolymers, metal ion-crosslinked polyacrylic acid (PA) and its copolymers, maleic anhydride-grafted polypropylene (PP), maleic anhydride-grafted polyethylene (PE), and mixtures thereof. Among these, PVDF is particularly preferably used as a binder.

[0046] The amount of a binder in the positive electrode mixture layer 24 is not particularly limited, but is preferably 1 mass% to 15 mass%, and more preferably 3 mass% to 5 mass%, based on the total mass of a positive electrode active material, a solid electrolyte, a conductive auxiliary agent, and the binder. If the amount of the binder is too small, it tends to be impossible to form a positive electrode 20 with sufficient adhesive strength. Conversely, too large an amount of binder makes it difficult to achieve a sufficient volume or mass energy density, since conventional binders are electrochemically inert and do not contribute to the discharge capacity.

[0047] The conductive aid improves the electronic conductivity of the positive electrode mixture layer 24. Known binders can be used as conductive aids. Examples of conductive aids include carbon materials such as carbon black, graphite, carbon nanotubes, and graphene; metals such as aluminum, copper, nickel, stainless steel, iron, and amorphous metals; conductive oxides such as ITO; or mixtures thereof. The conductive aid can be in the form of powder or fibers.

[0048] The amount of a conductive auxiliary agent in the positive electrode mixture layer 24 is not particularly limited. When a conductive auxiliary agent is incorporated, the mass fraction of the conductive auxiliary agent is preferably 0.5 mass% to 20 mass%, and more preferably 1 mass% to 5 mass%, based on the total mass of a positive electrode active material, a solid electrolyte, the conductive auxiliary agent, and a binder. (Negative electrode)

[0049] As in Fig. 4, the negative electrode 30 has a negative electrode current collector 32 and a negative electrode mixture layer 34. The negative electrode mixture layer 34 comes into contact with the negative electrode current collector 32.

[0050] The negative electrode current collector 32 may be electron-conductive. The negative electrode current collector 32 is, for example, a metal such as copper, aluminum, nickel, stainless steel, or iron, or a conductive resin. The negative electrode current collector 32 may be in powder, foil, stamped, or foam form.

[0051] The negative electrode mixture layer 34 contains a negative electrode active material and optionally a solid electrolyte, a binder and a conductive aid.

[0052] The negative electrode active material is not particularly limited, as long as it is capable of reversibly occlusion and release of lithium ions, as well as insertion and desorption of lithium ions. Negative electrode active materials used in known solid electrolyte batteries can be used as the negative electrode active material.

[0053] Negative electrode active materials include, for example, carbon materials such as natural graphite, artificial graphite, mesocarbon microbeads, mesocarbon fibers (MCF), coke, glassy carbon and a calcined organic compound, metals such as Si, SiO x , Sn and aluminum, which can be combined with lithium, alloys of these metals, composites of these metals and carbon materials, oxides such as lithium titanate (Li4Ti5O 12 ) and SnO2 and metallic lithium. Natural graphite is preferred as the negative electrode active material.

[0054] A solid electrolyte contained in the negative electrode 30 is, for example, the solid electrolyte described above. The solid electrolyte contained in the negative electrode 30 may be different from the solid electrolyte described above.

[0055] The binder and conductive aid contained in the negative electrode 30 are the same as the binder and conductive aid contained in the positive electrode 20. <Außenkörper>

[0056] The outer body 50 houses the power generation element 40 inside. The outer body 50 prevents moisture or the like from the outside from entering the interior. The outer body 50 includes, for example, a metal foil 52 and a resin layer 54 laminated on each surface of the metal foil 52, as shown in Fig. 4. The outer body 50 is a metal laminated film formed by coating both sides of the metal foil 52 with the resin layer 54.

[0057] The metal foil 52 is, for example, aluminum foil or stainless steel foil. A resin film such as polypropylene can be used as the resin layer 54. The material constituting the resin layer 54 can be different between the inner and outer resin layers. For example, polymers such as polyethylene terephthalate (PET) and polyamide (PA) with a high melting point can be used as the outer material, and polyethylene (PE), polypropylene (PP), and the like can be used as the inner material. <Anschlüsse>

[0058] Terminals 60 and 62 are connected to the positive electrode 20 and the negative electrode 30, respectively. Terminal 60, which is connected to the positive electrode 20, is a positive electrode terminal, and terminal 62, which is connected to the negative electrode 30, is a negative electrode terminal. Terminals 60 and 62 are responsible for the external electrical connection. Terminals 60 and 62 are made of conductive materials such as aluminum, nickel, and copper. The connection method can be welding or screwing. Terminals 60 and 62 are preferably protected with insulating tape to prevent short circuits. [Method for manufacturing a solid electrolyte battery]

[0059] Next, a method for manufacturing a solid electrolyte battery according to the present embodiment will be described. First, a solid electrolyte is prepared. A solid electrolyte can be prepared, for example, by a method in which raw material powders containing predetermined elements in predetermined molar ratios are mixed together to trigger a mechanochemical reaction. The mechanochemical reaction is controlled so that unreacted raw materials remain in the solid electrolyte. In particular, by changing the number of rotations and the number of revolutions of a planetary ball mill, the synthesis time, and the state of the raw material powders at the time of supply, unreacted components of the raw materials can be reduced.

[0060] When a halide raw material is contained in a raw material powder, the halide raw material is likely to evaporate when the temperature is increased. For this reason, halogen gas can be introduced into the atmosphere during sintering to supplement the halogen. Furthermore, when the halide raw material is contained in a raw material powder, sintering can be performed by a hot-pressing method using a highly dense mold. In this case, due to the high density of the mold, evaporation of the halide raw material during sintering can be suppressed. Sintering in this way produces a solid electrolyte in the form of a sintered body composed of a compound with a predetermined composition.

[0061] Next, the positive electrode 20 is prepared. A positive electrode is prepared by applying a paste containing a positive electrode active material to the positive electrode current collector 22 and drying it to form the positive electrode mixture layer 24. The solid electrolyte described above may be added to the paste containing the positive electrode active material.

[0062] Subsequently, the negative electrode 30 is prepared. A negative electrode is prepared by applying a paste containing a negative electrode active material to the negative electrode current collector 32 and drying it to form the negative electrode mixture layer 34. The solid electrolyte described above may be added to the paste containing the negative electrode active material.

[0063] The power generation element 40 can be manufactured, for example, by a powder molding process. A guide with a hole portion is placed over the positive electrode 20 and filled with a solid electrolyte. Afterward, the surface of the solid electrolyte is smoothed, and the negative electrode 30 is placed on the solid electrolyte. As a result, the solid electrolyte is sandwiched between the positive electrode 20 and the negative electrode 30. Subsequently, the solid electrolyte is press-molded by applying pressure to the positive electrode 20 and the negative electrode 30. Through the press-molded process, a laminate is obtained in which the positive electrode 20, the solid electrolyte layer 10, and the negative electrode 30 are laminated in this order. External connections are then made with the

[0064] The positive electrode current collector 22 of the positive electrode 20 and the negative electrode current collector 32 of the negative electrode 30, which form the laminate, are welded by a known method to electrically connect the positive electrode current collector 22 or the negative electrode current collector 32 to each external terminal. Thereafter, the laminate connected to the external terminals is stored in the outer body 50, and an opening portion of the outer body 50 is sealed by heat sealing. A solid electrolyte battery 100 of the present embodiment is obtained by the method described above.

[0065] The solid electrolyte battery 100 according to the present embodiment contains the solid electrolyte described above, which results in smooth conduction of Li-ions and low internal resistance.

[0066] The embodiment of the present invention has been described in detail above with reference to the drawings. However, each configuration and combination of each embodiment is merely an example, and addition, omission, substitution, and other modifications of the configuration cannot be made within the scope of application and do not deviate from the gist of the present invention. [Examples] "Example 1" (Preparation of a solid electrolyte)

[0067] In a glove box with a dew point of approximately -75°C, raw material powders were weighed such that the molar ratio of zirconium chloride (ZrCl4) to lithium sulfate (Li2SO4) was 1:8. First, Li2SO4 was ground in a planetary ball mill for 1 hour before mixing. The milling speed was 300 rpm. The raw material powders were then placed in a sealed zirconia container for a planetary ball mill, into which zirconia balls had previously been placed. The sealed container was then covered with a lid, the lid was screwed onto the container body, and the space between the lid and the container was further sealed with polyimide tape. The polyimide tape is an effective means of protecting against moisture. The sealed zirconia container was then placed in the planetary ball mill.The number of rotations was set to 200 rpm, the number of rotations was set to 200 rpm, the raw material powders were mixed together with the rotation direction and the rotation direction in opposite directions to cause a mechanochemical reaction for 2 hours to form a solid electrolyte (Li4Zr. 0,25 (SO4)2Cl).

[0068] Planetary ball mills are typically installed in an atmosphere (atmospheric air). The sealed zirconia container for a planetary ball mill is screwed and sealed with polyimide tape, and when the sealed zirconia container is inserted into the planetary ball mill, it is firmly pressed and fixed. Therefore, even in normal atmosphere, the sealed zirconia container is expected to have virtually no moisture contamination from the ambient air. [XRD measurement]

[0069] An XRD measurement holder was filled with the prepared solid electrolyte in a glove box with a dew point of approximately -70°C under circulating argon gas. A polyimide tape (vacuum-dried at 70°C for 16 hours) was then applied to the XRD measurement holder to cover and seal the surface of the filling to prevent moisture ingress, and an XRD measurement sample was prepared. The XRD measurement sample was then taken out into atmospheric air and subjected to XRD measurement using an X-ray diffractometer (manufactured by PANalytical, X'Pert Pro). Cu-Kα (measurement wavelength = 0.799407 Å) was used as the X-ray source.

[0070] In addition, for the XRD measurement, only the polyimide tape used to prevent moisture was attached to the holder, and the background measurement was performed under the same conditions as the XRD measurement described above. An X-ray diffraction pattern of the prepared solid electrolyte had peaks at a diffraction angle of 2θ = 22.3° ± 1.0° and a diffraction angle of 2θ = 36.4° ± 1.0°. [XPS measurement]

[0071] In addition, an X-ray photoelectron spectroscopy measurement was performed. Sampling was carried out in a glove box with a dew point of approximately -70°C under circulating argon gas, and the sample was transported to an XPS measurement device in the absence of atmosphere. A Quantera 2 manufactured by PHI was used for the XPS measurement. As a result, peaks at 170 ± 0.5 eV and 532 ± 0.5 eV were observed in the prepared solid electrolyte. [Measurement of ionic conductivity]

[0072] The obtained solid electrolyte powder was then filled into a mold in a glove box with a dew point of approximately -70°C under circulating argon gas and pressed with a weight of approximately 30 kN to produce a measuring cell for ionic conductivity.

[0073] The mold consists of a polyetheretherketone (PEEK) cylinder with a diameter of 10 mm and upper and lower punches with a diameter of 9.99 mm made of SKD11 material.

[0074] Next, a stainless steel disc and a Teflon (registered trademark) disc with a diameter of 50 mm and a thickness of 5 mm, with screw holes at four locations, were prepared to set a die as follows. A stainless steel disc, a Teflon (registered trademark) disc, a die, a Teflon (registered trademark) disc, and a stainless steel disc were stacked in this order, and four screws were tightened with a torque of approximately 3 Nm. Additionally, screws were inserted into the screw holes on the side surfaces of the upper and lower punches to serve as external connection ports.

[0075] The external connection terminals were connected to a potentiostat (VersaSTAT3, manufactured by Princeton Applied Research) equipped with a frequency response analyzer to measure ionic conductivity using an impedance measurement method. The measurement was performed in a measurement frequency range of 1 MHz to 0.1 Hz, an amplitude of 10 mV, and a temperature of 25°C. The ionic conductivity of the solid electrolyte from Example 1 was 1.1 × 10 -3 S / cm. "Examples 2 to 8"

[0076] Examples 2 to 8 differ from Example 1 in that the materials and molar ratios of the raw material powders were changed. The solid electrolytes in Examples 2 to 8 were also measured in the same manner as in Example 1. The configuration, molar ratio, and measurement results of each raw material are listed below in Table 1. "Examples 9 to 21"

[0077] Examples 9 to 21 differ from Example 1 in that the materials and molar ratios of the raw material powders were changed, and the preparation conditions of the solid electrolytes were changed. The solid electrolytes in Examples 9 to 21 were also measured in the same way as in Example 1.

[0078] Examples 9 to 21 were prepared according to the following procedure. First, zirconium chloride (ZrCl4), lithium sulfate (Li2SO4), and other raw materials were weighed in a glove box with a dew point of approximately -75°C in a predetermined molar ratio. Then, before mixing, Li2SO4 was pulverized with a planetary ball mill at a rotation frequency of 300 rpm for 1 hour. ZrCl4 was then added, and the mixture was further pulverized at a rotation frequency of 200 rpm for 1 hour. The pulverized sample and other raw materials were then placed in a sealed zirconia container for a planetary ball mill, into which zirconia balls had previously been placed.Then, the number of rotations was set to 200 rpm, the number of rotations to 200 rpm, and the rotation direction and the rotation direction were set in opposite directions to cause a mechanochemical reaction for a predetermined period of time to prepare a desired solid electrolyte.

[0079] The solid electrolytes in Examples 9 to 21 were also measured in the same manner as in Example 1. The configuration, molar ratio, and measurement results of each raw material are listed below in Table 1. "Examples 22 to 25"

[0080] Examples 22 to 25 differ from Example 1 in that the materials and molar ratios of the raw material powders were changed, and the preparation conditions of the solid electrolytes were changed. The solid electrolytes in Examples 22 to 25 were also measured in the same way as in Example 1.

[0081] Examples 22 to 25 were prepared according to the following procedure. First, in a glove box with a dew point of -75°C, Li2O, ZrCl4, and Li2SO4 were each weighed in a predetermined molar ratio. First, Li2SO4 was pulverized at a rotation frequency of 200 rpm for 1 hour before mixing. Subsequently, Li2O and ZrCl4 were mixed at a rotation frequency of 300 rpm for 48 hours, and then Li2SO4 was added to effect a mechanochemical reaction over a predetermined period of time to prepare a desired solid electrolyte.

[0082] The solid electrolytes in Examples 22 to 25 were also measured in the same manner as in Example 1. The configuration, molar ratio, and measurement results of each raw material are listed in Table 2 below. "Example 26"

[0083] Example 26 differs from Example 1 in that the materials and molar ratios of the raw material powders were changed, and the preparation conditions of the solid electrolyte were changed. The solid electrolyte in Example 26 was also measured in the same way as in Example 1.

[0084] First, Li3PO4, ZrCl4, and Li2SO4 were each weighed in a predetermined molar ratio in a glove box with a dew point of -75°C. First, Li2SO4 was pulverized for 1 hour at a rotation frequency of 200 rpm before mixing. Subsequently, Li3PO4 and ZrCl4 were mixed for 24 hours at a rotation frequency of 300 rpm, and then Li2SO4 was added to cause a mechanochemical reaction over a predetermined period to produce a desired solid electrolyte.

[0085] The solid electrolyte was also measured in Example 26 in the same manner as in Example 1. The configuration, molar ratio, and measurement results of each raw material are shown in Table 2 below. "Examples 27 to 29"

[0086] Examples 27 to 29 differ from Example 1 in that the materials and molar ratios of the raw material powders were changed, and the preparation conditions of the solid electrolytes were changed. The solid electrolytes in Examples 27 to 29 were also measured in the same way as in Example 1.

[0087] First, Li2O and LiX were mixed in a molar ratio of 2:1 in a glove box with a dew point of -75°C. Mixing was carried out using the planetary ball mill described above at a rotation frequency of 300 rpm for 48 hours. Subsequently, the LZSOC synthesized in Example 4 was added to initiate a mechanochemical reaction at a rotation frequency of 200 rpm for a specified period of time to produce the desired solid electrolyte.

[0088] The solid electrolytes in Examples 27 to 29 were also measured in the same manner as in Example 1. The configuration, molar ratio, and measurement results of each raw material are listed below in Table 2. "Examples 30 and 31"

[0089] Examples 30 and 31 differ from Example 4 in the dew point in a dry room during mixing. The dew point for Example 30 was set to -40°C, and the dew point for Example 31 was set to -60°C. For the other conditions, the solid electrolytes were measured in the same manner as in Example 4. The configuration, molar ratio, and measurement results of each raw material are listed below in Table 2. "Examples 32 to 34"

[0090] Examples 32 to 34 differ from Example 1 in that the materials and molar ratios of the raw material powders were changed, and the preparation conditions of the solid electrolytes were changed. The solid electrolytes in Examples 32 to 34 were also measured in the same way as in Example 1.

[0091] First, ZrCl4 and LiX were mixed in a predetermined molar ratio in a glove box with a dew point of -75°C. Mixing was carried out using the planetary ball mill described above at a rotation frequency of 300 rpm for 24 hours. Subsequently, the LZSOC synthesized in Example 4 was added to initiate a mechanochemical reaction at a rotation frequency of 200 rpm for a specified period of time to produce the desired solid electrolyte.

[0092] The solid electrolytes in Examples 32 to 34 were also measured in the same manner as in Example 1. The configuration, molar ratio, and measurement results of each raw material are listed below in Tables 3 and 4. "Examples 35 to 45"

[0093] Examples 35 to 45 differ from Example 1 in that the materials and molar ratios of the raw material powders were changed, and the preparation conditions of the solid electrolytes were changed. The solid electrolytes in Examples 35 to 45 were also measured in the same manner as in Example 1.

[0094] First, ZrCl4, LiCl, and LiX were mixed in a predetermined molar ratio in a glove box with a dew point of -75°C. Mixing was carried out using the planetary ball mill described above at a rotation frequency of 300 rpm for 24 hours. Subsequently, the LZSOC synthesized in Example 4 was added to initiate a mechanochemical reaction at a rotation frequency of 200 rpm for a specified period of time to produce the desired solid electrolyte.

[0095] The solid electrolytes in Examples 35 to 45 were also measured in the same manner as in Example 1. The configuration, molar ratio, and measurement results of each raw material are listed below in Tables 3 and 4. "Comparison examples 1 to 11"

[0096] Comparative Examples 1 to 11 differ from Example 1 in that the materials and molar ratios of the raw material powders were changed, and the preparation conditions of the solid electrolytes were changed. The solid electrolytes in Comparative Examples 1 to 11 were also measured in the same manner as in Example 1.

[0097] A method for producing solid electrolytes according to Comparative Examples 1 to 11 differs from the method for producing the solid electrolyte according to Example 1 in the reaction time of a mechanochemical reaction (mixing time of raw material powders) and in that the number of rotations and the number of revolutions of a planetary ball mill during the mechanochemical reaction was 300 rpm and Li2SO4 is used without being pulverized before mixing.

[0098] The solid electrolytes in Comparative Examples 1 to 11 were also measured in the same manner as in Example 1. The configuration, molar ratio, and measurement results of each raw material are shown in Table 2 below. In addition, Fig. 5 X-ray diffraction results of Comparative Example 4. In Comparative Example 4, no peaks were observed at a diffraction angle 2θ = 22.3 °± 1.0° and a diffraction angle 2θ = 36.4 °± 1.0°. Fig. The X-ray diffraction pattern shown in Figure 5 was obtained by removing the background data of the polyimide tape from the measurement results. (Comparison example 12)

[0099] Example 12 differs from Example 4 in the dew point in a dry room during mixing. The dew point in Comparative Example 12 was set to -20°C. For the other conditions, the solid electrolytes were measured in the same manner as in Example 4. The configuration, molar ratio, and measurement results of each raw material are listed below in Table 2. [Table 1] raw material Molar ratio Mixing time Solid electrolyte XRD Ionic conductivity of Li (S / cm) Rate characteristics (1C / 0.1C) Substance A Substance B Substance C Substance A Substance B Substance C 22,3 °± 1,0° 36,4 °± 1,0° Example 1 Li2SO4 ZrCl4 8 1 2 Li4Zr 0,25 (SO4)2Cl A A 1,1E-03 61 Example 2 Li2SO4 ZrCl4 6 1 3 Li6Zr 0,5 (SO4)3Cl2 A A 1,3E-03 63 Example 3 Li2SO4 ZrCl4 2 1 4 Li4Zr(SO4)2Cl4 A A 1,5E-03 64 Example 4 Li2SO4 ZrCl4 1 1 5 Li2Zr(SO4)Cl4 A A 2,4E-03 75 Example 5 Li2SO4 ZrCl4 1 2 6 LiZr(SO4) 0,5 Cl4 A B 2,0E-03 73 Example 6 Li2SO4 ZrCl4 1 4 7 Li 0,3 Zr(SO4) 0,25 Cl4 A B 1,5E-03 65 Example 7 Zr(SO4)2 Li2SO4 LiCl 1 0,1 1 8 Li 1,2 Zr(SO4) 2,1 Cl A B 1,0E-03 61 Example 8 Zr(SO4)2 Li2SO4 LiCl 1 0,05 0,5 8 Li 0,6 Zr(SO4) 0,25 Cl 0,5 A B 1,0E-03 60 Example 9 Zr(SO4)2 Li2SO4 ZrCl4 0.5 1 1 5 Li2Zr 1,3 (SO4)2Cl4 A B 1,2E-03 62 Example 10 Zr(SO4)2 Li2SO4 ZrCl4 0.4 1 1,5 5 Li2Zr 1,9 (SO4) 1,8 Cl6 A A 1,2E-03 61 Example 11 Li2SO4 NaSO4 ZrCl4 0,6 0,4 1 5 LiNaZr(SO4)2Cl4 A B 1,8E-03 70 Example 12 Li2SO4 KSO4 ZrCl4 0,7 0,3 1 5 LiKZr(SO4)2Cl4 A A 1,5E-03 67 Example 13 Li2SO4 RbSO4 ZrCl4 0,8 0,2 1 5 LiRbZr(SO4)2Cl4 A A 1,4E-03 67 Example 14 Li2SO4 CsSO4 ZrCl4 0,9 0,1 1 5 LiCsZr(SO4)2Cl4 A A 1,2E-03 62 Example 15 Li2SO4 AlCl3 ZrCl4 1 0,2 0,8 5 Li2Zr 0,8 Al 0,2 (SO4)Cl 3,8 A B 2,2E-03 73 Example 16 Li2SO4 GaCl3 ZrCl4 1 0,2 0,8 5 Li2Zr 0,8 Ga 0,2 (SO4)Cl 3,8 A B 2,2E-03 72 Example 17 Li2SO4 InCl3 ZrCl4 1 0,2 0,8 5 Li2Zr 0,8 In 0,2 (SO4)Cl 3,8 A B 2,5E-03 77 Example 18 Li2SO4 ScCl3 ZrCl4 1 0,2 0,8 5 Li2Zr 0,8 Sc 0,2 (SO4)Cl 3,8 A B 2,7E-03 80 Example 19 Li2SO4 YCl3 ZrCl4 1 0,2 0,8 5 Li2Zr 0,8 Y 0,2 (SO4)Cl 3,8 A B 1,5E-03 66 Example 20 Li2SO4 TiCl4 ZrCl4 1 0,2 0,8 5 Li2Zr 0,8 Y 0,2 (SO4)Cl4 A B 1,4E-03 64 Example 21 Li2SO4 HfCl4 ZrCl4 1 0,1 0,9 5 Li2Zr 0,9 Hf 0,1 (SO4)Cl4 A B 2,1E-03 73 [Table 2] raw material Molar ratio Mixing time Solid electrolyte XRD Ionic conductivity of Li (S / cm) Rate characteristics (1C / 0.1C) Substance A Substance B Substance C Substance A Substance B Substance C 22,3 °± 1,0° 36,4 °± 1,0° Example 22 LZOC Li2SO4 1 2 0,5 Li5Zr(SO4)2OCl4 A B 1,2E-03 63 Example 23 LZOC Li2SO4 1 1 0,5 Li4Zr(SO4)OCl4 A B 1,7E-03 68 Example 24 LZOC Li2SO4 1 0,5 0,5 Li3Zr(SO4) 0,5 OCl4 A B 2,3E-03 74 Example 25 LZOC Li2SO4 1 0,1 0,5 Li 2,2 Zr(SO4) 0,1 OCl4 A B 2,8E-03 80 Example 26 LZPOC Li2SO4 1 1 0,5 Li2,5Zr(SO4) 0,5 (PO4)o,5Cl4 A B 2,5E-03 78 Example 27 Li3O2I2 LZSOC 0,5 1 0,2 Li 4,5 Zr(SO4)OCl4I 0,5 A B 2,1E-03 73 Example 28 Li3O2Br LZSOC 0,5 1 0,2 Li 4,5 Zr(SO4)OCl4Br 0,5 A B 2,3E-03 75 Example 29 Li3O2F LZSOC 0,5 1 0,2 Li 4,5 Zr(SO4)OC14F 0,5 A B 1,8E-03 70 Example 30 H2O LZSOC 0,1 1 5 Li2Zr(SO4)O 0,1 Cl4H 0,2 A B 1,2E-03 62 Example 31 H2O LZSOC 0,025 1 5 Li2Zr(SO4)O 0,025 Cl4H 0.05 A B 2,2E-03 74 Comparison example 1 Li2SO4 ZrCl4 8 1 2 Li Zr 40.25 (SO) 42 Cl B B 1,2E-05 3 Comparison example 2 Li2SO4 ZrCl4 6 1 3 Li6Zr 0,5 (SO4)3Cl2 B B 3,3E-05 8 Comparison example 3 Li2SO4 ZrCl4 2 1 4 Li4Zr(SO4)2Cl4 B B 1,9E-04 30 Comparison example 4 Li2SO4 ZrCl4 1 1 5 Li2Zr(SO4)Cl4 B B 4,0E-04 40 Comparison example 5 Li2SO4 ZrCl4 1 2 6 LiZr(SO4) 0,5 Cl4 B B 5,5E-04 42 Comparison example 6 Li2SO4 ZrCl4 1 4 7 Li 0,3 Zr(SO4) 0,25 Cl4 B B 7,8E-04 50 Comparison example 7 Li2SO4 ZrCl4 16 1 1 Li8Zr 0,25 (SO4)4Cl A A 3,4E-05 8 Comparison example 8 Li2SO4 Na2SO4 ZrCl4 4 4 1 3 LiNa7Zr 0,25 (SO4)4Cl A A 6,2E-05 14 Comparison example 9 AlCl3 Li2SO4 ZrCl4 1,5 1 1 5 Li2ZrAl 1,5 (SO4)Cl 8,5 A A 2,8E-04 34 Comparison example 10 Zr(SO4)2 LiBF4 1 7 7 Li7Zr(SO4)2(BF4)7Cl4 B B 9,4E-05 25 Comparison example 11 Li2SO4 Zr(SO4)2 ZrCl4 1 3 1 5 Li2Zr4(SO4)7Cl4 A A 7,8E-05 22 Comparison example 12 H2O LZSOC 0,25 1 5 Li2Zr(SO4)Cl4 A B 8,5E-04 54 [Table 3] raw material Molar ratio Mixing time Solid electrolyte Substance A Substance B Substance C Substance D Substance A Substance B Substance C Substance D Example 32 LZSOC ZrCl4 LiBO2 1 1 2 1 Li2Zr(SO4) 0,5 (BO2)Cl4 Example 33 LZSOC ZrCl4 Li2CO3 1 1 1 1 Li2Zr(SO4) 0,5 (CO3) 0,5 Cl4 Example 34 LZSOC ZrCl4 Li2SiO3 1 1 1 1 Li2Zr(SO4) 0,5 (SiO3) 0,5 Cl4 Example 35 LZSOC ZrCl4 LiCl LiOH 1 1 1 1 4 Li2Zr(SO4) 0,3 (OH) 0,3 Cl 4,3 Example 36 LZSOC ZrCl4 LiCl LiBF4 1 1 1,5 0,5 0,5 Li2Zr(SO4) 0,5 (BF4) 0,25 Cl 4,75 Example 37 LZSOC ZrCl4 LiCl LiPF6 1 1 1,9 0,1 0,5 Li2Zr(SO4) 0,5 (PF6) 0,05 Cl 4,95 Example 38 LZSOC ZrCl4 LiCl Li(BOB) 1 1 1,9 0,1 0,5 Li2Zr(SO4) 0,5 (BOB) 0,05 Cl 4,95 Example 39 LZSOC ZrCl4 LiCl HCOOLi 1 1 1,5 0,5 1 Li2Zr(SO4) 0,5 (HCOO) 0,25 Cl 4,75 Example 40 LZSOC ZrCl4 LiCl (COOLi)2 1 1 1 0,5 2 Li2Zr(SO4) 0,5 ((COO)2) 0,25 Cl 4,5 Example 41 LZSOC ZrCl4 LiCl Li3N 1 1 1 0,334 2 Li2Zr(SO4) 0,3 N 0,167 Cl 4,3 Example 42 LZSOC ZrCl4 LiCl LiAlCl4 1 1 1 1 2 Li2Zr(SO4) 0,5 (AlCl4) 0,5 Cl 4.5 Example 43 LZSOC ZrCl4 LiCl CF3SO3Li 1 1 1,9 0,1 0,5 Li2Zr(CF3SO3) 0,05 Cl 4,95 Example 44 LZSOC ZrCl4 LiCl CH3COOLi 1 1 1,5 0,5 1 Li2Zr(SO4) 0,5 (CH3COO) 0,25 Cl 4,5 Example 45 LZSOC ZrCl4 LiCl CH3COOLi 1 1 1,5 0,5 1 Li2Zr(SO4) 0,5 (CH3COO) 0,25 Cl 4,5 [Table 4] XRD Ionic conductivity of Li (S / cm) Rate characteristics (1C / 0.1C) 22,3 °± 1,0° 36,4 °± 1,0° Example 32 A B 1,7E-03 69 Example 33 A B 1,8E-03 71 Example 34 A B 1,9E-03 71 Example 35 A B 2,2E-03 73 Example 36 A B 1,4E-03 66 Example 37 A B 1,2E-03 63 Example 38 A B 1,1E-03 61 Example 39 A B 1,5E-03 68 Example 40 A B 1,7E-03 70 Example 41 A B 1,9E-03 72 Example 42 A B 1,2E-03 64 Example 43 A B 1,4E-03 67 Example 44 A B 1,3E-03 65 Example 45 A B 1,3E-03 66

[0100] In Tables 1 and 2 described above, LZOC is a mixture of Li2O and ZrCl4. LZSOC is a mixture of Li2SO4 and ZrCl4. LZPOC is a mixture of Li3PO4 and ZrCl4. "A" in the XRD column means that the peak was observed, and "B" means that no peak was observed. In XPS analysis, peaks at 170 ± 0.5 eV and 532 ± 0.5 eV were observed in both the examples and comparative examples. (Production of a solid-state battery)

[0101] A solid-state battery was also manufactured in a glove box with a dew point of approximately -70°C. The solid-state battery was manufactured using a pellet manufacturing tool. The pellet manufacturing tool consists of a 10 mm diameter polyetheretherketone (PEEK) holder and an upper and lower punch with a diameter of 9.99 mm. The upper and lower punches are made of die steel (SKD11 material).

[0102] The lower punch was inserted into the PEEK holder of the pelletizing die, and 50 mg of a solid electrolyte was added to the lower punch. Subsequently, the resin holder was vibrated to smooth the surface of the solid electrolyte, and then the upper punch was placed on the solid electrolyte and pressed with a press with a weight of approximately 4 kN.

[0103] The lower punch was then removed, and 10 mg of a negative electrode mixture was placed on the solid electrolyte. The PEEK holder was then vibrated to smooth the surface of the negative electrode mixture, and the lower punch was placed on the negative electrode mixture and pressed with a press with a weight of approximately 3 kN. The negative electrode mixture consists of a negative electrode active material and the solid electrolyte described above, and lithium titanate (LTO) with an average particle diameter of 6.0 μm was used as the negative electrode active material. Next, the upper punch was removed, and 10 mg of a positive electrode mixture was placed on the solid electrolyte layer. The PEEK holder was then vibrated to smooth the surface of the positive electrode mixture, and the upper punch was placed on the positive electrode mixture and pressed with a press with a weight of approximately 3 kN.The positive electrode mixture consists of a positive electrode active material, carbon as a conductive aid, and the solid electrolyte described above. Lithium cobaltate (LCo) with an average particle diameter of 7.5 μm was used as the positive electrode active material. In this way, an all-solid-state battery was fabricated in which the negative electrode mixture layer, the solid electrolyte layer, and the positive electrode mixture layer were stacked in this order.

[0104] In addition, two stainless steel plates with a diameter of 50 mm and a thickness of 5 mm and two Bakelite (registered trademark) plates with a diameter of 50 mm and a thickness of 2 mm were prepared. Four screw holes were then drilled into each of the two stainless steel plates and the two Bakelite (registered trademark) plates. The screw holes were located where, when stacking an electrochemical cell, the two stainless steel plates and the two Bakelite (registered trademark) plates, the two stainless steel plates and the two Bakelite (registered trademark) plates lie on top of each other in plan view, but do not overlap with the electrochemical cell in plan view.

[0105] Next, a stainless steel plate, a Bakelite (registered trademark) plate, the solid-state battery, a Bakelite (registered trademark) plate, and a stainless steel plate were stacked in this order. Screws were inserted into the screw holes described above and tightened with a torque of 1 Nm. This resulted in an all-solid-state battery in which the upper and lower dies of the electrochemical cell were insulated by the Bakelite (registered trademark) plates. The all-solid-state battery was then stored in a thermostatic bath at 25°C for 48 hours to stabilize the open-circuit voltage.

[0106] Rate characteristics were evaluated using the fabricated solid-state battery. The rate characteristics were evaluated based on the ratio of the discharge capacity at a discharge rate of 1 C to the discharge capacity at a discharge rate of 0.1 C (1 C / 0.1 C rate characteristics). Constant current charging (CC charging) was performed in a 25°C environment with a constant current of 0.1 C until the battery voltage reached 2.7 V. After reaching 2.7 V, the solid-state battery was charged until a current of 0.05 C was reached (CV charging). After that, the solid-state battery was discharged at a constant current of 0.1 C until the battery voltage reached 1.5 V (CC discharge), and the discharge capacity at 0.1 C was measured.Subsequently, the all-solid-state battery was recharged under the conditions described above and discharged at a discharge rate of 1 C until the battery voltage reached 1.5 V, and the discharge capacity was measured at 1 C. The measurement results are also summarized in Tables 1, 2, 3, and 4.

[0107] In addition, Fig. 6 shows the charge / discharge curves of Example 4 and Comparative Examples 3 and 4. Example 4 is indicated by alternating long and short dashed lines, Comparative Example 3 by dotted lines, and Comparative Example 4 by solid lines. As in Fig. 6, higher input / output characteristics were observed in Example 4 than in Comparative Examples 3 and 4. [Industrial applicability]

[0108] According to the present invention, a solid electrolyte with improved ionic conductivity can be obtained. LIST OF REFERENCE SYMBOLS 10 Solid electrolyte layer 20 Positive electrode 22 positive electrode current collectors 24 Positive electrode mixture layer 30 Negative electrode 32 negative electrode current collectors 34 Negative electrode mixture layer 40 Power generation element 50 outer bodies 52 metal foil 54 resin layer 60, 62 connection 100 solid electrolyte batteries QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2022-038447

[0002] Cited non-patent literature

[0000] Jianwen Liang et al., Journal of American Chemical Society 2020, 142, 7012-7022

[0005] < / stromerzeugungselement>

Claims

[1] A solid electrolyte comprising: Li a A b E c (SO4) d J e X r H h (1), where in formula (1), A is at least one element selected from alkaline earth metals and alkali metals other than Li, E is at least one element selected from the group consisting of Al, Ga, In, Sc, Y, Ti, Zr, Hf and lanthanides, J is at least one group selected from the group consisting of OH, BO2, BO3, BO4, B3O6, B4O7, CO3, NO3, AlO2, SiO3, SiO4, Si2O7, Si3O9, Si4O 11 , Si6O 18 , PO3, PO4, P2O7, P3O 10 , SO3, SO5, S2O3, S2O4, S2O5, S2O6, S2O7, S2O8, BF4, PF6, BOB, (COO)2, N, AlCl4, CF3SO3, CH3COO, CF3COO, OOC-(CH2)2-COO, OOC-CH2-COO, OOC-CH(OH)-CH(OH)-COO, OOC-CH(OH)-CH2-COO, C6H5SO3, OOC-CH=CH-COO, OOC-CH=CH-COO, C(OH)(CH2COOH)2COO, AsO4, BiO4, CrO4, MnO4, PtF6, PtCl6, PtBr6, PtI6, SbO4, SeO4, TeO4, HCOO, and O, X is at least one element selected from the group consisting of F, Cl, Br and I, 0.5 ≤ a < 6, 0 ≤ b < 6, 0 < c < 2, 0.1 < d ≤ 6.0, 0 < e ≤ 6.0, 0 < f ≤ 6.1, and 0 ≤ h ≤ 0.2 are satisfied, and a peak at a diffraction angle 2θ = 22.3 °± 1.0° is observed in an X-ray diffraction pattern using Cu-Kα as a line source. [2] The solid electrolyte according to claim 1, wherein a peak is observed at a diffraction angle 20 = 36.4 ° ± 1.0 ° in the X-ray diffraction pattern in which Cu-Kα is used as a line source. [3] The solid electrolyte according to claim 1 or 2, wherein a peak is observed at 170 ± 0.5 eV and 532 ± 0.5 eV in an X-ray photoelectron spectroscopy measurement. [4] The solid electrolyte according to any one of claims 1 to 3, wherein an ionic conductivity at 25°C is 1 mS / cm or more. [5] A solid electrolyte layer comprising: the solid electrolyte according to one of claims 1 to 4. [6] A solid electrolyte battery comprising: a negative electrode; a positive electrode; and a solid electrolyte layer located between the negative electrode and the positive electrode and containing a solid electrolyte, wherein at least one or more of the negative electrode, the positive electrode and the solid electrolyte layer contains the solid electrolyte according to any one of claims 1 to 4. [7] A solid electrolyte battery comprising: a negative electrode; a positive electrode; and the solid electrolyte layer according to claim 5 between the negative electrode and the positive electrode.

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