SOLID ELECTROLYTE, SOLID ELECTROLYTE LAYER AND SOLID ELECTROLYTE CELL

Abstract

Solid electrolyte comprising a compound composed of: an alkali metal; at least one metallic element with a valence of 1 to 6; an element of group XVII of the periodic table and an element of group XVI of the periodic table and is represented by the following formula (1), A 2 + a E 1 − b + α G b D c X d (In formula (1), A is an element selected from the group consisting of Li, K, and Na; E is at least a tetravalent element selected from the group consisting of Zr, Hf, Ti, and Sn; G is at least an element selected from the group consisting of B, Si, Mg, Ca, Sr, Cs, Ba, Y, Al, Sc, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Cu, Au, Pb, Bi, In, Sn, Sb, Nb, Ta, and W; D is at least an element selected from the group consisting of O, Se, and Te; X is at least an element selected from the group consisting of F, Cl, Br, and I; a is -2b in a case where G is a hexavalent element; a is -b in a case where G is a pentavalent element; a is zero in a case where G is a tetravalent element or G is not included; a is b in a case where G is a where G is a trivalent element, a is 2b in one case, where G is a divalent element, and a is 3b in one case where G is a monovalent element, b is 0 to 0.5, α is -0.3 to 0.3, c is 0,01 to 3 and d is 0.1 to 6.1).

Description

TECHNICAL FIELD

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

[0002] This application claims priority to Japanese Patent Application No. 2019-145665 filed in Japan on August 7, 2019, the contents of which are incorporated herein by reference. BACKGROUND

[0003] In recent years, electronics technology has advanced significantly, resulting in a reduction in size, weight, and thickness, as well as multifunctionality of mobile electronic devices. Accordingly, there is a strong demand for batteries used as power sources for electronic devices to reduce size, weight, and thickness, as well as improve reliability. Therefore, solid electrolyte batteries, which use a solid electrolyte as the electrolyte, are gaining increasing attention. Solid electrolytes include oxide-based solid electrolytes, sulfide-based solid electrolytes, complex hydride-based solid electrolytes (LiBH4 and the like), and the like.

[0004] Patent Document 1 discloses a solid electrolyte secondary battery having a positive electrode including a positive electrode layer with a positive electrode active material containing a Li element and a positive electrode current collector, a negative electrode including a negative electrode layer with a negative electrode active material and a negative electrode current collector, and a solid electrolyte disposed between the positive electrode layer and the negative electrode layer and composed of a compound represented by the following general formula. Li 3-2X M X In 1-Y M' Y L 6-Z The Z

[0005] (In the formula, M and M' are metal elements and L and L' are halogen elements. In addition, X, Y and Z independently satisfy the conditions 0 ≤ X ≤ 1.5, 0 ≤ Y ≤ 1 and 0 ≤ Z ≤ 6).

[0006] Patent Document 2 discloses a solid electrolyte material represented by the following composition formula (1). Li6−3ZYZX6 where 0 < Z ≤ 2 is satisfied, and X is Cl or Br.

[0007] In addition, Patent Document 2 describes a battery in which at least one of a negative electrode and a positive electrode contains the solid electrolyte material.

[0008] Patent Document 3 discloses a solid electrolyte battery having an electrode active material layer including an active material, a first solid electrolyte material in contact with the active material, an anion component different from an anion component of the active material, and a single-phase electron-ion mixed conductor, and a second solid electrolyte material in contact with the first solid electrolyte material, the same anion component as the anion component in the first solid electrolyte material, and an ion conductor without electron conductivity. Furthermore, Patent Document 3 discloses that the first solid electrolyte material is Li2ZrS3, the first solid electrolyte material has a peak of Li2ZrS3 at 2θ = 34.2° ± 0.5° in X-ray diffraction measurement using CuKα rays, and in a case where the diffraction intensity of the peak of Li2ZrS3 at 2θ = 34.2° ± 0.5° is represented by I Aand the diffraction intensity of the peak of ZrO2 at 2θ = 31.4° ± 0.5° by I B is specified, the value of I B / I A 0.1 or less. PRIOR ART DOCUMENTS Patent document Patent Document 1: Unexamined Japanese Patent Application, First Publication No. JP 2006-244734 A Patent Document 2: PCT International Publication No. WO 2018 / 025582 A1 Patent Document 3: Unexamined Japanese Patent Application, First Publication No. JP 2013-257992 A DISCLOSURE OF THE INVENTION Problems to be solved by the invention

[0009] However, in conventional solid-electrolyte batteries, the solid electrolytes used in the solid-electrolyte layers had insufficient ionic conductivity. Therefore, it was not possible to achieve sufficient discharge capacity in conventional solid-electrolyte batteries.

[0010] The present invention has been made in view of the above-described problems, and it is an object of the present invention to provide a solid electrolyte having a high ionic conductivity.

[0011] Another object of the present invention is to provide a solid electrolyte layer containing the above-described solid electrolyte and a solid electrolyte battery having a large discharge capacity containing the solid electrolyte layer. Solutions for these tasks

[0012] The inventors of the present invention have conducted intensive studies to solve the above-described problem.

[0013] As a result, the inventors found that a compound composed of an alkali metal, at least one of a metal element and a semimetal element having a valence of 1 to 6 (monovalent to hexavalent metal element and semimetal element), and an element of Group XVII of the Periodic Table is preferably used as a solid electrolyte, and thus arrived at an idea of ​​the present invention.

[0014] That is, the present invention relates to the following inventions. [1] A solid electrolyte comprising a compound composed of an alkali metal, at least one metal element with a valence of 1 to 6, an element of group XVII of the periodic table and an element of group XVI of the periodic table and is represented by the following formula (1). A2+aE1−b+αGbDcXd

[0015] (In formula (1), A is an element selected from the group consisting of Li, K, and Na. E is at least one tetravalent element selected from the group consisting of Zr, Hf, Ti, and Sn. G is at least one element selected from the group consisting of B, Si, Mg, Ca, Sr, Cs, Ba, Y, Al, Sc, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Cu, Au, Pb, Bi, In, Sn, Sb, Nb, Ta, and W. D is at least one element selected from the group consisting of O, Se, and Te. X is at least one element selected from the group consisting of F, Cl, Br, and I. a is -2b when G is a hexavalent element, a is -b when G is a pentavalent element, a is zero when G is a tetravalent element or G is not included, a is b when G is a trivalent element, a is 2b, if G is a divalent element and a is 3b, if G is a monovalent element. b is 0 to 0.5, α is -0.3 to 0.3, c is 0.01 to 3, d is 0.1 to 6.1. [2] Solid electrolyte according to [1], in which in the compound represented by formula (1) G is a monovalent element. [3] Solid electrolyte according to [1], in which in the compound represented by formula (1) G is a divalent element. [4] Solid electrolyte according to [1], in which in the compound represented by formula (1) G is a trivalent element. [5] Solid electrolyte according to [1], in which in the compound represented by formula (1) G is a tetravalent element. [6] Solid electrolyte according to [1], in which in the compound represented by formula (1) G is a pentavalent element. [7] Solid electrolyte according to [1], in which in the compound represented by formula (1) G is a hexavalent element. [8] Solid electrolyte according to any one of items [1] to [7], wherein in the compound represented by formula (1) X is F. [9] Solid electrolyte according to any one of items [1] to [7], wherein in the compound represented by formula (1) X is Cl.

[10] Solid electrolyte according to any one of items [1] to [7], wherein in the compound represented by formula (1) X is Br.

[11] Solid electrolyte according to any one of items [1] to [7], wherein in the compound represented by formula (1) XI is.

[12] Solid electrolyte according to any one of [1] to

[11] , wherein in the compound represented by formula (1) DO is.

[13] Solid electrolyte according to any one of items [1] to

[11] , wherein in the compound represented by formula (1) D is Se.

[14] Solid electrolyte according to any one of items [1] to

[11] , wherein in the compound represented by formula (1) D is Te.

[15] Solid electrolyte according to [1], in which in the compound represented by formula (1) A is Li, E is Zr, DO is and X is Cl.

[16] Solid electrolyte according to [1], in which in the compound represented by formula (1) A is Li, E is Zr, DO is and XI is.

[17] Solid electrolyte according to any one of items [1] to

[16] , further comprising 0.1 to 1.0 mass% of at least one compound selected from the group consisting of: A2O (A is an element selected from the group consisting of Li, K and Na); AX (A is an element selected from the group consisting of Li, K and Na. X is at least one element selected from the group consisting of F, Cl, Br and I.); EO2 (E is at least one tetravalent element selected from the group consisting of Zr, Hf, Ti and Sn); EX4 (E is at least one tetravalent element selected from the group consisting of Zr, Hf, Ti and Sn, and X is at least one element selected from the group consisting of F, Cl, Br and I) and GO n(G is at least one element selected from the group consisting of B, Si, Mg, Ca, Sr, Cs, Ba, Y, Al, Sc, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Cu, Au, Pb, Bi, In, Sn, Sb, Nb, Ta and W. n is 0.5 when G is a monovalent element, n is 1 when G is a divalent element, n is 1.5 when G is a trivalent element, n is 2 when G is a tetravalent element, n is 2.5 when G is a pentavalent element and n is 3 when G is a hexavalent element.).

[18] Solid electrolyte layer comprising the solid electrolyte according to any one of items [1] to

[17] .

[19] A solid electrolyte battery comprising a solid electrolyte layer, a positive electrode and a negative electrode, wherein at least one of the solid electrolyte layer, the positive electrode and the negative electrode contains the solid electrolyte according to any one of [1] to

[17] .

[20] A solid electrolyte battery comprising a solid electrolyte layer, a positive electrode and a negative electrode, wherein the solid electrolyte layer contains the solid electrolyte according to any one of items [1] to

[17] . Effects of the invention

[0016] According to the present invention, it is possible to provide a solid electrolyte with high ionic conductivity. Furthermore, the solid electrolyte layer of the present invention contains the solid electrolyte of the present invention with high ionic conductivity. Therefore, solid electrolyte batteries containing the solid electrolyte layer of the present invention have low internal resistance and large discharge capacity. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic cross-sectional view of a solid electrolyte battery according to the present embodiment. EMBODIMENTS FOR CARRYING OUT THE INVENTION

[0017] A solid electrolyte, a solid electrolyte layer, and a solid electrolyte battery of the present invention are described in detail below. [Solid Electrolyte]

[0018] A solid electrolyte of the present embodiment comprises a compound composed of an alkali metal, at least one of a metal element and a semimetal element having a valence of 1 to 6, an element of Group XVII of the Periodic Table, and an element of Group XVI of the Periodic Table.

[0019] The solid electrolyte of the present embodiment may be in the form of a powder (particle) containing the compound, or may be in the form of a sintered body obtained by sintering a powder containing the compound. Furthermore, the solid electrolyte of the present embodiment may be in the form of a compact formed by compressing a powder, a compact obtained by forming a mixture of a powder and a binder, or a coating film formed by coating a paint containing a powder, a binder, and a solvent, and then removing the solvent by heating.

[0020] The solid electrolyte of the present embodiment comprises a compound represented by the following formula (1). A2+aE1−b+αGbDcXd

[0021] (In formula (1), A is an element selected from the group consisting of Li, K, and Na. E is at least one tetravalent element selected from the group consisting of Zr, Hf, Ti, and Sn. G is at least one element selected from the group consisting of B, Si, Mg, Ca, Sr, Cs, Ba, Y, Al, Sc, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Cu, Au, Pb, Bi, In, Sn, Sb, Nb, Ta, and W. D is at least one element selected from the group consisting of O, Se, and Te. X is at least one element selected from the group consisting of F, Cl, Br, and I. a is -2b when G is a hexavalent element, a is -b when G is a pentavalent element, a is zero when G is a tetravalent element or G is not included, a is b when G is a trivalent element, a is 2b when G is a divalent element, and a is 3b when G is a monovalent element. b is 0 to 0.5, α is -0.3 to 0.3, c is 0.01 to 3, d is 0.1 to 6.1.)

[0022] In the compound represented by formula (1), A is an element selected from the group consisting of Li, K and Na. A is preferably Li.

[0023] In the compound represented by formula (1), a is -2b when G is a hexavalent element, a is -b when G is a pentavalent element, a is zero when G is a tetravalent element or G is not included, a is ab when G is a trivalent element, a is 2b when G is a divalent element, and a is 3b when G is a monovalent element. In the compound represented by formula (1), since a is the above-described numerical value determined depending on the valence of G, the amount of A is appropriate, and a solid electrolyte with high ionic conductivity is obtained.

[0024] In the compound represented by formula (1), E is at least one tetravalent element selected from the group consisting of Zr, Hf, Ti and Sn. Zr and / or Hf is preferably contained as E, with Zr being particularly preferred in order to obtain a solid electrolyte with a high ionic conductivity.

[0025] In the compound represented by formula (1), G is at least one element selected from the group consisting of B, Si, Mg, Ca, Sr, Cs, Ba, Y, Al, Sc, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Cu, Au, Pb, Bi, In, Sn, Sb, Nb, Ta and W.

[0026] In the compound represented by formula (1), G may be a monovalent element selected from Au and Cs among the elements described above.

[0027] In the compound represented by formula (1), G may be a divalent element selected from Mg, Ca, Ba, Cu, Sn, Pb and Sr among the elements described above.

[0028] In the compound represented by formula (1), G may be a trivalent element selected from B, Y, Al, Sc, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Bi, In, and Sb among the elements described above. When G is trivalent, G is preferably Y to obtain a solid electrolyte with high ionic conductivity.

[0029] In the compound represented by formula (1), G can be Si or Sn, which is a tetravalent element, among the elements described above. When G is tetravalent, G is preferably Sn to obtain a solid electrolyte with high ionic conductivity.

[0030] In the compound represented by formula (1), G may be a pentavalent element selected from Nb and Ta among the elements described above. When G is pentavalent, G is preferably Nb and / or Ta, and more preferably Ta, in order to obtain a solid electrolyte with high ionic conductivity.

[0031] In the compound represented by formula (1), G may be W, which is a hexavalent element, among the elements described above. When G is hexavalent, G is preferably W to obtain a solid electrolyte with high ionic conductivity.

[0032] In the compound represented by formula (1), b is 0 to 0.5, and G may not be included. However, G is preferably included to obtain a solid electrolyte with high ionic conductivity.

[0033] When G is contained in the compound of formula (1), b is preferably 0.02 or more. Furthermore, b is set to 0.5 or less to prevent a decrease in the ionic conductivity of the solid electrolyte due to an excessive amount of G. In the compound represented by formula (1), b is preferably 0.2 or less.

[0034] In the compound represented by formula (1), D is at least one element selected from the group consisting of O, Se, and Te. O is particularly preferably included as D in order to obtain a solid electrolyte with high ionic conductivity.

[0035] In the compound represented by formula (1), when D is at least one element selected from the group consisting of O, Se, and Te, the crystallinity of the compound deteriorates because each of the above-described elements, which are divalent anions, is present at a position where X, which is a monovalent anion, should be. Therefore, the ionic conductivity improves, which is preferable.

[0036] In the compound represented by formula (1), D is an essential element. In the compound represented by formula (1), c is 0.01 to 3, preferably 0.3 to 2.0. Since c is 0.01 or more, a sufficient effect of improving ionic conductivity is achieved by the inclusion of D. c is set to 3 or less to prevent a decrease in the ionic conductivity of the solid electrolyte due to an excessive amount of D.

[0037] In the compound represented by formula (1), X is at least one element selected from the group consisting of F, Cl, Br and I. As X, Cl and / or I is preferably contained in order to obtain a solid electrolyte having a high ionic conductivity, and Cl is particularly preferably contained in order to obtain a solid electrolyte having a particularly high ionic conductivity.

[0038] In the compound represented by formula (1), when X is F, a solid electrolyte having sufficiently high ionic conductivity and excellent oxidation resistance is obtained, which is preferable.

[0039] In the compound represented by formula (1), when X is Cl, a solid electrolyte with a high ionic conductivity and a favorable balance between oxidation and reduction resistance (resistance to reduction) is obtained, which is preferable.

[0040] In the compound represented by formula (1), when X is Br, a solid electrolyte with a sufficiently high ionic conductivity and a favorable balance between oxidation and reduction resistance is obtained, which is preferable.

[0041] In the compound represented by formula (1), when XI is , a solid electrolyte having a high ionic conductivity is obtained, which is preferable.

[0042] In the compound represented by formula (1), X is an essential element, and d is 0.1 to 6.1, preferably 2.0 to 5.4. Since d is 0.1 or more, an effect of improving ionic conductivity due to the presence of X is sufficiently achieved. In addition, since d is 6.1 or less, a decrease in the ionic conductivity of the solid electrolyte due to an excessive amount of X is not caused.

[0043] In the compound represented by formula (1), since the ratio of E to A is within a suitable range, a solid electrolyte with high ionic conductivity is obtained. Therefore, α is -0.3 to 0.3, preferably -0.2 to 0.2, and particularly preferably -0.1 to 0.1.

[0044] In the compound represented by formula (1), it is preferable that A is Li, E is Zr, DO, and X is Cl to obtain a solid electrolyte having excellent reduction resistance and high ionic conductivity.

[0045] In the compound represented by formula (1), A may be Li, E may be Zr, D may be O, and X may be I to obtain a solid electrolyte having excellent reduction resistance and high ionic conductivity.

[0046] In the compound represented by formula (1), the ratio between the ionic radius of X and the ionic radius of E per valence is preferably 7.0 to 15.0, and more preferably 8.0 to 13.0. The ionic radius of E per valence refers to a value obtained by dividing the ionic radius of E by the valence.

[0047] When the ratio between the ionic radius of X and the ionic radius of E per valence is 7.0 or more, the ions of A in formula (1) are easily mobile, and a solid electrolyte with high ionic conductivity can be obtained. When the ratio between the ionic radius of X and the ionic radius of E per valence is 15.0 or less, thermal stability improves, which is preferable.

[0048] The solid electrolyte of the present embodiment preferably contains, together with the compound described above, 0.1 to 1.0 mass% of at least one compound selected from the group consisting of A2O (A is an element selected from the group consisting of Li, K and Na), AX (A is an element selected from the group consisting of Li, K and Na. X is at least one element selected from the group consisting of F, Cl, Br and I), EO2 (E is at least one tetravalent element selected from the group consisting of Zr, Hf, Ti and Sn), EX4 (E is at least one tetravalent element selected from the group consisting of Zr, Hf, Ti and Sn. X is at least one element selected from the group consisting of F, Cl, Br and I) and GO n(G is at least one element selected from the group consisting of B, Si, Mg, Ca, Sr, Cs, Ba, Y, Al, Sc, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Cu, Au, Pb, Bi, In, Sn, Sb, Nb, Ta and W. n is 0.5 when G is a monovalent element, n is 1 when G is a divalent element, n is 1.5 when G is a trivalent element, n is 2 when G is a tetravalent element, n is 2.5 when G is a pentavalent element and n is 3 when G is a hexavalent element.).

[0049] The solid electrolyte, which together with the compound described above, contains 0.1 to 1.0 mass% of at least one compound selected from the group consisting of A2O, AX, EO2, EX4 and GO n selected has a higher ionic conductivity. The details of the reason for this are not clear, but are considered as follows.

[0050] In such a solid electrolyte, A2O, AX, EO2, EX4 and GO nThe function of supporting the ionic bonds between the particles composed of the compound described above is assumed to reduce the grain boundary resistance between the particles composed of the compound described above, and this makes it possible to maintain high ionic conductivity throughout the solid electrolyte.

[0051] If the amount of at least one compound selected from the group consisting of A2O, AX, EO2, EX4 and GO n contained in the solid electrolyte is 0.1 mass% or more, the effect of reducing the grain boundary resistance between the particles composed of the compound described above due to the contained A2O, AX, EO2, EX4 and GO n significant. In addition, if the amount of at least one compound selected from the group consisting of A2O, AX, EO2, EX4 and GO nis selected is 1.0 mass% or less, no case where the amount of A2O, AX, EO2, EX4 and GO n becomes too large, which makes solid electrolyte layers containing the solid electrolyte hard and which makes it difficult to form favorable interfaces that support the ionic bonds between the particles composed of the compound described above. (Process for producing a solid electrolyte)

[0052] When the solid electrolyte of the present embodiment is in powder form, the solid electrolyte can be produced by a method in which, for example, raw material powders containing predetermined elements are mixed in a predetermined molar ratio and reacted.

[0053] When the solid electrolyte of the present embodiment is in the form of a sintered body, the solid electrolyte can be manufactured, for example, by a method to be described below. First, raw material powders containing predetermined elements are mixed in a predetermined molar ratio. Next, the mixture of raw material powders is formed into a predetermined shape and sintered in a vacuum or in an inert gas atmosphere. A halide raw material contained in the raw material powders is likely to evaporate when the temperature is increased. Therefore, a halogen can be supplemented by having a halogen gas in the atmosphere at the time of sintering the mixture. Furthermore, the mixture can be sintered in a highly dense mold by a hot-pressing method. Since the mold is very dense in this case, the evaporation of the halide raw material by sintering can be suppressed.When the mixture is sintered as described above, a solid electrolyte in the form of a sintered body composed of a compound having a predetermined composition is obtained.

[0054] A solid electrolyte of the present embodiment comprises a compound composed of an alkali metal, at least one of a metal element and a semimetal element having a valence of 1 to 6, an element of Group XVII of the Periodic Table, and an element of Group XVI of the Periodic Table. Therefore, the solid electrolyte of the present embodiment has high ionic conductivity.

[0055] Furthermore, the compound in the solid electrolyte of the present embodiment is the compound represented by formula (1) and therefore has high ionic conductivity. The details of the reason for this are not clear, but are considered as follows.

[0056] In the compound represented by formula (1), E is at least one tetravalent element selected from the group consisting of Zr, Hf, Ti and Sn. The ionic radii of Zr 4+ (six-fold coordination), Hf 4+ (six-fold coordination), Ti 4+ (six-fold coordination) and Sn 4+ (six-coordination) are 0.72 Å, 0.71 Å, 0.605 Å, and 0.690 Å, respectively. Dividing the ionic radius of each element by its valence yields, for example, 0.72 Å ÷ 4 = 0.18 Å in the case of Zr. 4+ , 0.18 Å in the case of Hf 4+ , 0.15 Å in the case of Ti 4+ and 0.17 Å in the case of Sn 4+ This value is referred to as the "ionic radius per valence." Furthermore, in the compound X represented by formula (1), at least one element is selected from the group consisting of F, Cl, Br, and I. The ionic radii of F - , Cl - , Br - and I -, which serve as X, are 1.33 Å, 1.81 Å, 1.96 Å, and 2.20 Å, respectively.

[0057] The relationship between the ionic radius of Cl - and the ionic radius of E per valence in formula (1) is thus, for example, 1.81 ÷ 0.18 = 10.1 in the case of Cl - and Zr 4+ . Similarly, the ratio is 10.2 in the case of Cl - and Hf 4+ , 12.0 in the case of Cl - and Ti 4+ and 10.5 in the case of Cl - and Sn 4+ . As described above, the ratios of the ionic radius of Cl - to the ionic radius per valence of the tetravalent cations (Zr 4+ , Hf 4+ , Ti 4+ and Sn 4+ ) than E sufficiently large.

[0058] Therefore, in the compound represented by formula (1) there is a free space between Cl - and the tetravalent cation (Zr 4+ , Hf 4+ , Ti 4+ or Sn 4+) than E in formula (1), and it is for Li + easy to move in the gaps between the atoms in the compound (to conduct electricity).

[0059] Furthermore, D in the compound represented by formula (1) is at least one element selected from the group consisting of O, Se and Te. Since D in formula (1) is an element with a weak Li + -capture force compared to E in formula (1), it is for Li + easy to move in the compound compared, for example, to a compound containing E instead of D in formula (1).

[0060] Since the compound represented by formula (1) has a large ionic radius ratio as described above and, moreover, D with a weak Li + -capturing force, Li +easily move into the gaps between the atoms of the compound. As a result, the compound represented by formula (1) is believed to exhibit high ionic conductivity.

[0061] In contrast, for example, Patent Document 2 describes a solid electrolyte material represented by a composition formula Li 6-3Z Y Z X6 (where 0 < Z < 2, and X is Cl or Br.) The ionic radius (six-coordination) of Y 3+ , which is a constituent element of the solid electrolyte material described in Patent Document 2, is 0.9 Å. Therefore, the ratio of the ionic radius of Cl - to the ionic radius per valence of Y 3+ 6.0. This value is smaller than the ratio of the ionic radius of Cl - to the ionic radius per valence of the tetravalent cation (Zr 4+ , Hf 4+ , Ti 4+ or Sn 4+ ) than E.

[0062] It is believed that this difference affects the movement of Li + facilitated and thereby it is possible to obtain high ionic conductivity in the compound represented by formula (1) compared with the solid electrolyte material described in Patent Document 2. [Solid electrolyte battery]

[0063] Fig. 1 is a schematic cross-sectional view of a solid electrolyte battery according to the present embodiment.

[0064] The Fig. The solid electrolyte battery 10 shown in Figure 1 comprises a positive electrode 1, a negative electrode 2 and a solid electrolyte layer 3.

[0065] The solid electrolyte layer 3 lies between the positive electrode 1 and the negative electrode 2. The solid electrolyte layer 3 contains the solid electrolyte described above.

[0066] The positive electrode 1 and the negative electrode 2 are connected to external terminals (not shown) and electrically connected to an external device.

[0067] The solid electrolyte battery 10 is charged or discharged by the transfer of ions between the positive electrode 1 and the negative electrode 2 through the solid electrolyte layer 3. The solid electrolyte battery 10 may be a laminate in which the positive electrode 1, the negative electrode 2, and the solid electrolyte layer 3 are laminated, or it may be a roll obtained by winding the laminate. The solid electrolyte battery is used in, for example, laminated batteries, rectangular batteries, cylindrical batteries, coin-like batteries, button-like batteries, and the like. (Positive electrode)

[0068] As in Fig.1, the positive electrode 1 includes the positive electrode mixture layer 1B provided on the sheet-shaped (foil-shaped) positive electrode current collector 1A. (positive electrode current collector)

[0069] The positive electrode current collector 1A must be made of an electron-conductive material that is resistant to oxidation during charging and does not corrode easily. Metals such as aluminum, stainless steel, nickel, and titanium, or conductive resins can be used. The positive electrode current collector 1A can be in powder, foil, stamped, or expanded form. (positive electrode mixed layer)

[0070] The positive electrode mixture layer 1B contains a positive electrode active material and contains a solid electrolyte, a binder, and a conductive aid, as required. (positive electrode active material)

[0071] The positive electrode active material is not particularly limited, as long as the positive electrode active material is capable of reversibly absorbing and desorbing lithium ions, and intercalating and deintercalating lithium ions, and it is possible to use positive electrode active materials used in known lithium-ion batteries. Examples of positive electrode active materials include lithium-containing metal oxides, lithium-containing metal-phosphorus oxides, and the like.

[0072] Examples of lithium-containing metal oxides include lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), lithium manganese spinel (LiMn2O4), compound metal oxides represented by a general formula: LiNi x Co y Mn zO2 (x + y + z = 1), lithium vanadium compounds (LiVOPO4 and Li3V2(PO4)3), olivine-type LiMPO4 (where M denotes at least one element selected from Co, Ni, Mn and Fe), lithium titanate (Li4Ti5O 12 ) and the like.

[0073] In addition, positive electrode active materials that do not contain lithium can also be used. Examples of such positive electrode active materials include metal oxides that do not contain lithium (MnO2, V2O5, and the like), metal sulfides that do not contain lithium (MoS2 and the like), fluorides that do not contain lithium (FeF3, VF3, and the like), and the like.

[0074] When using such a positive electrode active material that does not contain lithium, the lithium ions must be pre-doped into the negative electrode, or a negative electrode containing lithium ions must be used. (Binder)

[0075] A binder is preferably included in the positive electrode mixture layer 1B to bind the positive electrode active material, the solid electrolyte, and the conductive auxiliary agent constituting the positive electrode mixture layer 1B and to adhere the positive electrode mixture layer 1B to the positive electrode current collector 1A. Examples of required properties of the binder include oxidation resistance, favorable adhesion, and the like.

[0076] Examples of the binder used in the positive electrode mixture layer 1B include polyvinylidene fluoride (PVDF) and its copolymers, polytetrafluoroethylene (PTFE), polyamide (PA), polyimide (PI), polyamide-imide (PAI), polybenzimidazole (PBI), polyethersulfone (PES), polyacrylic acids (PA) and their copolymers, metal ion crosslinked products of polyacrylic acids (PA) and their copolymers, polypropylene (PP) to which maleic anhydride is grafted, polyethylene (PE) to which maleic anhydride is grafted, mixtures thereof, and the like. Among these, PVDF is particularly preferably used as the binder.

[0077] The proportion of the solid electrolyte in the positive electrode mixture layer 1B is not particularly limited, but is preferably 1 vol% to 50 vol%, and more preferably 5 vol% to 30 vol% based on the total mass of the positive electrode active material, the solid electrolyte, the conductive auxiliary agent, and the binder.

[0078] The content of the binder in the positive electrode mixture layer 1B 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 the positive electrode active material, the solid electrolyte, the conductive auxiliary agent, and the binder. If the amount of the binder is too small, it tends to become impossible to form the positive electrode 1 with sufficient bonding strength. Conversely, if the amount of the binder is too large, since ordinary binders are electrochemically inactive and thus do not contribute to the discharge capacity, it tends to become difficult to obtain a sufficient volume or mass energy density. (Conductive aid)

[0079] The conductive aid is not particularly limited as long as it improves the electronic conductivity of the positive electrode mixture layer 1B. Known conductive aids can be used. Examples 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; and mixtures thereof.

[0080] The conductive aid can be in powder form or in the form of fibers.

[0081] The proportion of the conductive auxiliary agent in the positive electrode mixture layer 1B is not particularly limited. When the conductive auxiliary agent is added, the proportion is normally preferably 0.5 mass% to 20 mass%, and more preferably 1 mass% to 5 mass%, based on the total mass of the positive electrode active material, the solid electrolyte, the conductive auxiliary agent, and the binder. (Negative electrode)

[0082] As in Fig. 1, the negative electrode 2 includes the negative electrode mixture layer 2B provided on the negative electrode current collector 2A. (negative electrode current collector)

[0083] The negative electrode current collector 2A must be conductive, and metals such as copper, aluminum, nickel, stainless steel, and iron, or conductive resin films can be used. The negative electrode current collector 2A can be in powder form, film form, stamped form, or expanded form. (negative electrode mixed layer)

[0084] The negative electrode mixture layer 2B contains a negative electrode active material and contains a solid electrolyte, a binder, and a conductive aid, as required. (negative electrode active material)

[0085] The negative electrode active material is not particularly limited as long as the negative electrode active material is capable of reversibly absorbing and desorbing lithium ions and intercalating and deintercalating lithium ions, and it is possible to use negative electrode active materials used in known lithium-ion batteries.

[0086] Examples of the negative electrode active material include carbon materials such as natural graphite, artificial graphite, mesocarbon microbeads, mesocarbon fibers (MCF), coke, glassy carbon and sintered products of organic compounds, metals that can be combined with lithium such as Si, SiO x , Sn and aluminum, their alloys, composite materials of the metal and the carbon material, oxides such as lithium titanate (Li4Ti5O 12 ) and SnO2, metallic lithium and the like. (Binder)

[0087] The negative electrode mixture layer 2B preferably contains a binder to bind the negative electrode active material, the solid electrolyte, and the conductive auxiliary agent constituting the negative electrode mixture layer 2B and to adhere the negative electrode mixture layer 2B to the negative electrode current collector 2A. Examples of required properties of the binder include reduction resistance, favorable adhesion, and the like.

[0088] Examples of the binder used in the negative electrode mixture layer 2B include polyvinylidene fluoride (PVDF) and its copolymers, polytetrafluoroethylene (PTFE), polyamide (PA), polyimide (PI), polyamide-imide (PAI), polybenzimidazole (PBI), styrene-butadiene rubber (SBR), carboxymethyl cellulose (CMC), polyacrylic acids (PA) and their copolymers, metal ion crosslinked products of polyacrylic acids (PA) and their copolymers, polypropylene (PP) to which maleic anhydride is grafted, polyethylene (PE) to which maleic anhydride is grafted, mixtures thereof, and the like. Among these, one or more of the following materials are preferably used as the binder: SBR, CMC, and PVDF.

[0089] The proportion of the solid electrolyte in the negative electrode mixture layer 2B is not particularly limited, but is preferably 1 vol% to 50 vol%, and more preferably 5 vol% to 30 vol% based on the total mass of the negative electrode active material, the solid electrolyte, the conductive auxiliary agent, and the binder.

[0090] The proportion of the binder in the negative electrode mixture layer 2B is not particularly limited, but is preferably 1 mass% to 15 mass%, and more preferably 1.5 mass% to 10 mass%, based on the total mass of the negative electrode active material, the conductive auxiliary agent, and the binder. If the amount of the binder is too small, it tends to become impossible to form the negative electrode 2 with sufficient bonding strength. Conversely, if the amount of the binder is too large, since binders are usually electrochemically inactive and thus do not contribute to the discharge capacity, it tends to become difficult to obtain a sufficient volume or mass energy density. (Conductive aid)

[0091] As the conductive aid that can be contained in the negative electrode mixture layer 2B, the same conductive aid as the above-described conductive aid that can be contained in the positive electrode mixture layer 1B, such as carbon materials, can be used.

[0092] The proportion of the conductive aid in the negative electrode mixture layer 2B is not particularly limited. When the conductive aid is added, the proportion is usually preferably 0.5 mass% to 20 mass%, and more preferably 1 mass% to 12 mass%, relative to the negative electrode active material. (Outer casing)

[0093] In the solid electrolyte battery 10 of the present embodiment, a battery element composed of the positive electrode 1, the solid electrolyte layer 3, and the negative electrode 2 is housed and sealed in an outer casing. The outer casing must be an outer casing capable of suppressing the penetration of moisture or the like from the outside into the interior, and is not particularly limited.

[0094] For example, an outer casing can be used that is made by molding a metal laminate film into a bag shape. The metal laminate film is produced by coating both surfaces of a metal foil with polymer films. Such an outer casing is sealed by heat-sealing an opening part.

[0095] For example, aluminum foil, stainless steel foil, and the like can be used as the metal foil forming the metal laminate film. A polymer with a high melting point, such as polyethylene terephthalate (PET), polyamide, and the like, is preferably used as the polymer film disposed outside the outer casing. Polyethylene (PE), polypropylene (PP), and the like are preferably used as the polymer film disposed inside the outer casing. (External connections)

[0096] A positive electrode terminal is electrically connected to the positive electrode 1 of the battery element, and a negative electrode terminal is electrically connected to the negative electrode 2. In the present embodiment, the positive electrode terminal is electrically connected to the positive electrode current collector 1A, and the negative electrode terminal is electrically connected to the negative electrode current collector 2A. The connecting portion between the positive electrode current collector and the negative electrode current collector, respectively, and the external terminal (the positive electrode terminal or the negative electrode terminal) is arranged inside the outer casing.

[0097] External connectors can be made of a conductive material such as aluminum or nickel.

[0098] A film of PE grafted with maleic anhydride (hereinafter referred to in some cases as "acid-modified PE") or PP grafted with maleic anhydride (hereinafter referred to in some cases as "acid-modified PP") is preferably disposed between the outer casing and the external terminal. Areas where an acid-modified PE or acid-modified PP film is disposed are heat-sealed, making the solid electrolyte battery advantageous in terms of adhesion between the outer casing and the external terminals. [Method for manufacturing a solid electrolyte battery]

[0099] Next, a method for manufacturing the solid electrolyte battery according to the present embodiment will be described.

[0100] First, the above-described solid electrolyte serving as the solid electrolyte layer 3 in the solid electrolyte battery 10 of the present embodiment is prepared. In the present embodiment, a powdered solid electrolyte is used as the material of the solid electrolyte layer 3. The solid electrolyte layer 3 can be prepared by a powder molding method.

[0101] Furthermore, for example, a paste containing a positive electrode active material is applied to the positive electrode current collector 1A and dried to form the positive electrode mixture layer 1B; and thereby, the positive electrode 1 is manufactured. Furthermore, for example, a paste containing a negative electrode active material is applied to the negative electrode current collector 2A and dried to form the negative electrode mixture layer 2B; and thereby, the negative electrode 2 is manufactured.

[0102] Next, a guide with a hole is installed on the positive electrode 1, for example, and the solid electrolyte is loaded into the guide. After that, the surface of the solid electrolyte is flattened, and the negative electrode 2 is placed on the solid electrolyte. The solid electrolyte is sandwiched between the positive electrode 1 and the negative electrode 2. Pressure is then applied to the positive electrode 1 and the negative electrode 2, causing the solid electrolyte to undergo compression deformation. The solid electrolyte is compression-formed, resulting in a laminate in which the positive electrode 1, the solid electrolyte layer 3, and the negative electrode 2 are laminated in this order.

[0103] Further, external terminals are welded to the positive electrode current collector in the positive electrode 1 and the negative electrode current collector in the negative electrode 2, which form the laminate, using a known method. This electrically connects the positive electrode current collector and the negative electrode current collector to the external terminals. The laminate connected to the external terminals is then housed in an outer casing, and the opening portion of the outer casing is sealed by heat sealing.

[0104] The solid electrolyte battery 10 of the present embodiment is obtained through the steps described above.

[0105] In the method for manufacturing the solid electrolyte battery 10 described above, a case in which the solid electrolyte is used in the form of a powder has been described, but a solid electrolyte in the form of a sintered body may also be used.

[0106] In this case, the solid electrolyte battery 10 having the solid electrolyte layer 3 is obtained by a method in which the solid electrolyte is arranged in the form of a sintered body between the positive electrode 1 and the negative electrode 2 and is subjected to compression deformation.

[0107] The solid electrolyte layer 3 of the present embodiment contains the solid electrolyte of the present embodiment having a high ionic conductivity.

[0108] Therefore, the solid electrolyte battery 10 of the present embodiment including the solid electrolyte layer 3 of the present embodiment has a low internal resistance and a large discharge capacity.

[0109] So far, the embodiment of the present invention has been described in detail with reference to the drawings. The respective configurations in the embodiment, a combination thereof, and the like are examples, and addition, omission, replacement, and other modifications of the configuration are possible within the scope of the features of the present invention. EXAMPLES (Example 1 to Example 79 and Comparative Example 1)

[0110] Solid electrolytes of Example 1 to Example 79 in the form of powders composed of compounds having the compositions shown in Table 5 to Table 8 were prepared by a method in which raw material powders containing predetermined raw materials in the molar ratios shown in Table 1 to Table 4 were mixed and reacted for 24 hours using a planetary ball mill with the rotation speed set to 1 rpm, the orbital speed set to 500 rpm, and the rotation direction and the orbital direction set to opposite directions.

[0111] The compositions of the respective solid electrolytes were obtained by analyzing the respective elements, excluding oxygen, using a high-frequency inductively coupled plasma (ICP) atomic emission spectrometer (manufactured by Shimadzu Corporation). For solid electrolytes containing fluorine, the amounts of fluorine contained in the solid electrolytes were analyzed using an ion chromatography device (manufactured by Thermo Fisher Scientific Inc.).

[0112] In addition, the oxygen contents in the raw material powders listed in Tables 1 to 4 were indicated as the oxygen contents in the respective solid electrolytes in Tables 5 to 8. It was confirmed that the oxygen content in the solid electrolyte could be considered the same as the oxygen content in the raw material powder by conducting a preliminary experiment.

[0113] In addition, a zirconia container and zirconia balls were used as the sealed container and balls for the planetary ball mill. Therefore, zirconium from the sealed container and balls was included as a contaminant in the produced compounds. It was known that the contamination amount of zirconium from the sealed container and balls was a certain constant. Tables 5 to 8 show the actual measured values ​​of the zirconium amounts in the compounds. (Example 80 to Example 84)

[0114] Li2O, LiCl, ZrO2, ZrCl4, and CaO were added or mixed as additives (0.1 mass%) to the solid electrolyte (Li2ZrOCl4) prepared in Example 16, and solid electrolytes were thereby prepared.

[0115] Table 1 to Table 4 show the raw materials used for the respective solid electrolytes, the mixing ratios (molar ratio) of the raw materials, the ionic radii of “X” when the compositions of the respective solid electrolytes were substituted into the formula (1), and the ratios of the ionic radius of “X” to the ionic radius per valence of “E”, respectively.

[0116] Furthermore, in Table 5 to Table 8, for the compositions of the respective solid electrolytes, "O" is indicated in a case where the above-described formula (1) was satisfied, and "-" is indicated in a case where the above-described formula (1) was not satisfied. Furthermore, Table 5 to Table 8 show "A", "E", "G", "D", "valence of G", "X", "a", "b", "a", "c", and "d" when the compositions of the respective solid electrolytes were respectively applied to the formula (1). Table 1 Raw materials Proportions of mixed raw materials (molar ratio) Ionic radius of X (Å) Ratio of the ionic radius of X to the ionic radius per valence of E Material A Material B Material C Material D Material E Material A Material B Material C Material D Material E Example 1 LiCl Li2O YCl3 - - 2,98 0,01 1,0 - - 1,81 6,0 Example 2 LiCl Li2O YCl3 - - 2,94 0,03 1,0 - - 1,81 6,0 Example 3 LiCl Li2O YCl3 - - 2,80 0,1 1,0 - - 1,81 6,0 Example 4 LiCl Li2O YCl3 - - 2,40 0,3 1,0 - - 1,81 6,0 Example 5 LiCl Li2O YCl3 - - 2,00 0,5 1,0 - - 1,81 6,0 Example 6 LiCl Li2O YCl3 - - 1,00 1,0 1,0 - - 1,81 6,0 Example 7 Li2O - YCl3 - - 1,50 - 1,0 - - 1,81 6,0 Example 8 Li2O Y2O3 YCl3 - - 1,50 0,17 0,67 - - 1,81 6,0 Example 9 Li2O Y2O3 YCl3 - - 1,50 0,33 0,33 - - 1,81 6,0 Example 10 Li2O Y2O3 YCl3 - - 1,50 0,48 0,03 - - 1,81 6,0 Example 11 LiCl Li2O ZrCl4 - - 1,98 0,01 1,0 - - 1,81 10,1 Example 12 LiCl Li2O ZrCl4 - - 1,94 0,03 1,0 - - 1,81 10,1 Example 13 LiCl Li2O ZrCl4 - - 1,80 0,1 1,0 - - 1,81 10,1 Table 1 (continued) Raw materials Proportions of mixed raw materials (molar ratio) Ionic radius of X (Å) Ratio of the ionic radius of X to the ionic radius per valence of E Material A Material B Material C Material D Material E Material A Material B Material C Material D Material E Example 14 LiCl Li2O ZrCl4 - - 1,40 0,3 1,0 - - 1,81 10,1 Example 15 LiCl Li2O ZrCl4 - - 1,00 0,5 1,0 - - 1,81 10,1 Example 16 - Li2O ZrCl4 - - - 1,0 1,0 - - 1,81 10,1 Example 17 ZrO2 Li2O ZrCl4 - - 0,25 1,0 0,75 - - 1,81 10,1 Example 18 ZrO2 Li2O ZrCl4 - - 0,50 1,0 0,50 - - 1,81 10,1 Example 19 ZrO2 Li2O ZrCl4 - - 0,75 1,0 0,25 - - 1,81 10,1 Example 20 ZrO2 Li2O ZrCl4 - - 0,975 1,0 0,025 - - 1,81 10,1 Example 21 - Li2O HfCl4 - - - 1,0 1,0 - - 1,81 10,2 Example 22 - Li2O TiCl4 - - - 1,0 1,0 - - 1,81 12,0 Example 23 - Li2O SnCl4 - - - 1,0 1,0 - - 1,81 10,5 Example 24 LiCl Li2O ZrCl4 CsCl - 0,3 1,0 0,9 0,1 - 1,81 10,1 Example 25 LiCl Li2O ZrCl4 CsCl - 0,6 1,0 0,8 0,2 - 1,81 10,1 Table 2 Raw materials Proportions of mixed raw materials (molar ratio) Ionic radius of X (Å) Ratio of the ionic radius of X to the ionic radius per valence of E Material A Material B Material C Material D Material E Material A Material B Material C Material D Material E Example 26 LiCl Li2O ZrCl4 CsCl - 0,9 1,0 0,7 0,3 - 1,81 10,1 Example 27 LiCl Li2O ZrCl4 AuCl - 0,3 1,0 0,9 0,1 - 1,81 10,1 Example 28 LiCl Li2O ZrCl4 MgCl2 - 0,2 1,0 0,9 0,1 - 1,81 10,1 Example 29 LiCl Li2O ZrCl4 CaCl2 - 0,2 1,0 0,9 0,1 - 1,81 10,1 Example 30 LiCl Li2O ZrCl4 BaCl2 - 0,2 1,0 0,9 0,1 - 1,81 10,1 Example 31 LiCl Li2O ZrCl4 SnCl2 - 0,2 1,0 0,9 0,1 - 1,81 10,1 Example 32 LiCl Li2O ZrCl4 SrCl2 - 0,2 1,0 0,9 0,1 - 1,81 10,1 Example 33 LiCl - ZrCl4 B2O3 - 2,1 - 0,9 0,05 - 1,81 10,1 Example 34 LiCl Li2O ZrCl4 BiCl3 - 0,1 1,0 0,9 0,1 - 1,81 10,1 Example 35 LiCl Li2O ZrCl4 InCl3 - 0,1 1,0 0,9 0,1 - 1,81 10,1 Example 36 LiCl Li2O ZrCl4 SbCl3 - 0,1 1,0 0,9 0,1 - 1,81 10,1 Example 37 LiCl Li2O ZrCl4 YCl3 - 0,1 1,0 0,95 0,05 - 1,81 9,8 Example 38 LiCl Li2O ZrCl4 YCl3 - 0,1 1,0 0,9 0,1 - 1,81 9,5 Example 39 LiCl Li2O ZrCl4 YCl3 - 0,2 1,0 0,8 0,2 - 1,81 9,0 Example 40 LiCl Li2O ZrCl4 YCl3 - 0,3 1,0 0,7 0,3 - 1,81 8,5 Example 41 LiCl Li2O ZrCl4 YCl3 - 0,4 1,0 0,6 0,4 - 1,81 8,1 Example 42 LiCl Li2O ZrCl4 YCl3 - 0,5 1,0 0,5 0,5 - 1,81 7,7 Example 43 LiCl Li2O ZrCl4 AlCl3 - 0,1 1,0 0,9 0,1 - 1,81 10,1 Example 44 LiCl Li2O ZrCl4 ScCl3 - 0,1 1,0 0,9 0,1 - 1,81 10,1 Example 45 LiCl Li2O ZrCl4 LaCl3 - 0,1 1,0 0,9 0,1 - 1,81 10,1 Table 3 Raw materials Proportions of mixed raw materials (molar ratio) Ionic radius of X (Å) Ratio of the ionic radius of X to the ionic radius per valence of E Material A Material B Material C Material D Material E Material A Material B Material C Material D Material E Example 46 LiCl Li2O ZrCl4 CeCl3 - 0,1 1,0 0,9 0,1 - 1,81 10,1 Example 47 LiCl Li2O ZrCl4 PrCl3 - 0,1 1,0 0,9 0,1 - 1,81 10,1 Example 48 LiCl Li2O ZrCl4 NdCl3 - 0,1 1,0 0,9 0,1 - 1,81 10,1 Example 49 LiCl Li2O ZrCl4 PmCl3 - 0,1 1,0 0,9 0,1 - 1,81 10,1 Example 50 LiCl Li2O ZrCl4 SmCl3 - 0,1 1,0 0,9 0,1 - 1,81 10,1 Example 51 LiCl Li2O ZrCl4 EuCl3 - 0,1 1,0 0,9 0,1 - 1,81 10,1 Example 52 LiCl Li2O ZrCl4 GdCl3 - 0,1 1,0 0,9 0,1 - 1,81 10,1 Example 53 LiCl Li2O ZrCl4 TbCl3 - 0,1 1,0 0,9 0,1 - 1,81 10,1 Example 54 LiCl Li2O ZrCl4 DyCl3 - 0,1 1,0 0,9 0,1 - 1,81 10,1 Example 55 LiCl Li2O ZrCl4 HoCl3 - 0,1 1,0 0,9 0,1 - 1,81 10,1 Example 56 LiCl Li2O ZrCl4 ErCl3 - 0,1 1,0 0,9 0,1 - 1,81 10,1 Example 57 LiCl Li2O ZrCl4 TmCl3 - 0,1 1,0 0,9 0,1 - 1,81 10,1 Example 58 LiCl Li2O ZrCl4 YbCl3 - 0,1 1,0 0,9 0,1 - 1,81 10,1 Example 59 LiCl Li2O ZrCl4 LuCl3 - 0,1 1,0 0,9 0,1 - 1,81 10,1 Example 60 LiCl - ZrCl4 SiO2 - 2,0 - 0,9 0,1 - 1,81 10,1 Example 61 LiCl Li2O ZrCl4 SnCl4 - - 1,0 0,9 0,1 - 1,81 10,1 Example 62 ZrO2 Li2O ZrCl4 NbCl5 - 0,025 0,95 0,875 0,1 - 1,81 10,1 Example 63 ZrO2 Li2O ZrCl4 TaCl5 - 0,025 0,95 0,875 0,1 - 1,81 10,1 Example 64 ZrO2 Li2O ZrCl4 WCl6 - 0,050 0,90 0,850 0,1 - 1,81 10,1 Example 65 - Li2O ZrF4 - - - 1,0 1,0 - - 1,33 7,4 Table 4 Raw materials Proportions of mixed raw materials (molar ratio) Ionic radius of X (Å) Ratio of the ionic radius of X to the ionic radius per valence of E Material A Material B Material C Material D Material E Material A Material B Material C Material D Material E Example 66 - Li2O ZrBr4 - - - 1,0 1,0 - - 1,96 10,9 Example 67 - Li2O ZrI4 - - - 1,0 1,0 - - 2,20 12,2 Example 68 - Li2O ZrCl4 ZrF4 - - 1,0 0,75 0,25 - 1,69 9,4 Example 69 - Li2O ZrCl4 ZrBr4 - - 1,0 0,75 0,25 - 1,85 10,3 Example 70 - Li2O ZrCl4 ZrI4 - - 1,0 0,75 0,25 - 1,91 10,6 Example 71 - Li2O ZrF4 ZrBr4 - - 1,0 0,25 0,75 - 1,80 10,0 Example 72 - Li2O ZrF4 ZrI4 - - 1,0 0,25 0,75 - 1,98 11,0 Example 73 - Li2O ZrBr4 ZrI4 - - 1,0 0,50 0,50 - 2,08 11,6 Example 74 - Li2O ZrCl4 ZrF4 ZrBr4 - 1,0 0,50 0,25 0,25 1,73 9,6 Example 75 - Li2O ZrCl4 ZrF4 ZrI4 - 1,0 0,50 0,25 0,25 1,79 9,9 Example 76 - Li2O ZrCl4 ZrBr4 ZrI4 - 1,0 0,50 0,25 0,25 1,95 10,8 Example 77 - Li2O ZrF4 ZrBr4 ZrI4 - 1,0 0,25 0,25 0,50 1,92 10,7 Example 78 - Li2Se ZrCl4 - - - 1,0 1,0 - - 1,81 10,1 Example 79 - Li2Te ZrCl4 - - - 1,0 1,0 - - 1,81 10,1 Example 80 - Li2O ZrCl4 - - - 1,0 1,0 - - 1,81 10,1 Example 81 - Li2O ZrCl4 - - - 1,0 1,0 - - 1,81 10,1 Example 82 - Li2O ZrCl4 - - - 1,0 1,0 - - 1,81 10,1 Example 83 - Li2O ZrCl4 - - - 1,0 1,0 - - 1,81 10,1 Example 84 - Li2O ZrCl4 - - - 1,0 1,0 - - 1,81 10,1 Comparison example 1 - LiCl ZrCl4 - - - 2,0 1,0 - - 1,81 10,1 Table 5 A 2+a E 1-b+α GBD c X d 0 ≤ b ≤ 0.5, -0.3 ≤ α ≤ 0.3, 0.01 ≤ c ≤ 3, 0.1 ≤ d ≤ 6.1 Fulfillment of formula (1) Solid electrolyte Ionic conductivity (mS cm -1 ) Discharge capacity (mAh) A E G D Value of G X a b α c d Example 1 Li Y - - - - - - - - - - - Li3YO 0,01 Cl 5,98 0,4 2,2 Example 2 Li Y - - - - - - - - - - - Li3YO 0,03 Cl 5,94 0,4 2,2 Example 3 Li Y - - - - - - - - - - - Li3YO 0,1 Cl 5,8 0,5 2,3 Example 4 Li Y - - - - - - - - - - - Li3YO 0,3 Cl 5,4 0,7 2,5 Example 5 Li Y - - - - - - - - - - - Li3YO 0,5 Cl5 0,8 2,6 Example 6 Li Y - - - - - - - - - - - Li3YOCl4 1,0 2,8 Example 7 Li Y - - - - - - - - - - - Li3YO 1,5 Cl3 0,9 2,7 Example 8 Li Y - - - - - - - - - - - Li3YO2Cl2 0,8 2,6 Example 9 Li Y - - - - - - - - - - - Li3YO 2,5 Cl 0,7 2,5 Example 10 Li Y - - - - - - - - - - - Li3YO 2,95 Cl 0,1 0,5 2,3 Example 11 Li Zr - 0 - Cl - - 0,0 0,0 0,0 0,01 5,98 O Li2ZrO 0,01 Cl 5,98 1,7 3,8 Example 12 Li Zr - 0 - Cl - - 0,0 0,0 0,0 0,03 5,94 O Li2ZrO 0,03 Cl 5,94 1,8 4,0 Example 13 Li Zr - 0 - Cl - - 0,0 0,0 0,0 0,1 5,8 O Li2ZrO 0,1 Cl 5,8 1,8 4,1 Table 5 (continued) A 2+a E 1-b+α GBD c X d 0 ≤ b ≤ 0.5, -0.3 ≤ α ≤ 0.3, 0.01 ≤ c ≤ 3, 0.1 ≤ d ≤ 6.1 Fulfillment of formula (1) Solid electrolyte Ionic conductivity (mS cm -1 ) Discharge capacity (mAh) A E G D Value of G X a b α c d Example 14 Li Zr - 0 - Cl - - 0,0 0,0 0,0 0,3 5,4 O Li2ZrO 0,3 Cl 5,4 1,9 4,4 Example 15 Li Zr - 0 - Cl - - 0,0 0,0 0,0 0,5 5,0 O Li2ZrO 0,5 Cl5 2,0 4,6 Example 16 Li Zr - 0 - Cl - - 0,0 0,0 0,0 1,0 4,0 O Li2ZrOCl4 2,1 4,6 Example 17 Li Zr - 0 - Cl - - 0,0 0,0 0,0 1,5 3,0 O Li2ZrO 1,5 Cl3 2,0 4,5 Example 18 Li Zr - 0 - Cl - - 0,0 0,0 0,0 2,0 2,0 O Li2ZrO2Cl2 1,9 4,3 Example 19 Li Zr - 0 - Cl - - 0,0 0,0 0,0 2,5 1,0 O Li2ZrO 2,5 Cl 1,8 4,2 Example 20 Li Zr - 0 - Cl - - 0,0 0,0 0,0 2,95 0,1 O Li2ZrO 2,95 Cl 0,1 1,7 3,7 Example 21 Li Hf - 0 - Cl - - 0,0 0,0 0,0 1,0 4,0 O Li2HfOCl4 2,0 4,5 Example 22 Li Ti - 0 - Cl - - 0,0 0,0 0,0 1,0 4,0 O Li2TiOCl4 2,4 4,7 Example 23 Li Sn - 0 - Cl - - 0,0 0,0 0,0 1,0 4,0 O Li2SnOCl4 2,5 4,8 Example 24 Li Zr Cs 0 1 Cl - - 0,3 0,1 0,0 1,0 4,0 O Li 2,3 Zr 0,9 Cs 0,1 OCl4 2,5 4,7 Example 25 Li Zr Cs 0 1 Cl - - 0,6 0,2 0,0 1,0 4,0 O Li 2,6 Zr 0,8 Cs 0,2 OCl4 2,8 4,9 Table 6 A 2+a E 1-b+α GBD c X d 0 ≤ b ≤ 0.5, -0.3 ≤ α ≤ 0.3, 0.01 ≤ c ≤ 3, 0.1 ≤ d ≤ 6.1 Fulfillment of formula (1) Solid electrolyte Ionic conductivity (mS cm -1 ) Discharge capacity (mAh) A E G D Value of G X a b α c d Example 26 Li Zr Cs 0 1 Cl - - 0,9 0,3 0,0 1,0 4,0 O Li 2,9 Zr 0,7 Cs 0,3 OCl4 2,4 4,7 Example 27 Li Zr Au 0 1 Cl - - 0,3 0,1 0,0 1,0 4,0 O Li 2,3 Zr 0,9 Oh! 0,1 OCl4 2,1 4,4 Example 28 Li Zr Mg 0 2 Cl - - 0,2 0,1 0,0 1,0 4,0 O Li 2,2 Zr 0,9 Mg 0,1 OCl4 2,3 4,8 Example 29 Li Zr Ca 0 2 Cl - - 0,2 0,1 0,0 1,0 4,0 O Li 2,2 Zr 0,9 Ca 0,1 OCl4 2,3 4,7 Example 30 Li Zr Ba 0 2 Cl - - 0,2 0,1 0,0 1,0 4,0 O Li 2,2 Zr 0,9 Ba 0,1 OCl4 2,2 4,7 Example 31 Li Zr Sn 0 2 Cl - - 0,2 0,1 0,0 1,0 4,0 O Li 2,2 Zr 0,9 Sn 0,1 OCl4 2,2 4,8 Example 32 Li Zr Sr 0 2 Cl - - 0,2 0,1 0,0 1,0 4,0 O Li 2,2 Zr 0,9 Sr 0,1 OCl4 2,3 4,9 Example 33 Li Zr B 0 3 Cl - - 0,1 0,1 0,0 0,2 5,7 O Li 2,1 Zr 0,9 B 0,1 ON 0,15 Cl 5,7 2,3 4,9 Example 34 Li Zr Bi 0 3 Cl - - 0,1 0,1 0,0 1,0 4,0 O Li 2,1 Zr 0,9 Bi 0,1 OCl4 2,2 4,8 Example 35 Li Zr In 0 3 Cl - - 0,1 0,1 0,0 1,0 4,0 O Li 2,1 Zr 0,9 I n0,1 OCl4 2,3 4,8 Example 36 Li Zr Sb 0 3 Cl - - 0,1 0,1 0,0 1,0 4,0 O Li 2,1 Zr 0,9 Sb 0,1 OCl4 2,2 4,8 Example 37 Li Zr Y 0 3 Cl - - 0,05 0,05 0,0 1,0 4,0 O Li 2,05 Zr 0,95 Y 0,05 OCl4 2,3 4,7 Example 38 Li Zr Y 0 3 Cl - - 0,1 0,1 0,0 1,0 4,0 O Li 2,1 Zr 0,9 Y 0,1 OCl4 2,4 4,9 Example 39 Li Zr Y 0 3 Cl - - 0,2 0,2 0,0 1,0 4,0 O Li 2,2 Zr 0,8 Y 0,2 OCl4 2,3 4,8 Example 40 Li Zr Y 0 3 Cl - - 0,3 0,3 0,0 1,0 4,0 O Li 2,3 Zr 0,7 Y 0,3 OCl4 2,0 4,4 Example 41 Li Zr Y 0 3 Cl - - 0,4 0,4 0,0 1,0 4,0 O Li 2,4 Zr 0,6 Y 0,4 OCl4 1,8 4,2 Example 42 Li Zr Y 0 3 Cl - - 0,5 0,5 0,0 1,0 4,0 O Li 2,5 Zr 0,5 Y 0,5 OCl4 1,7 3,7 Example 43 Li Zr Al 0 3 Cl - - 0,1 0,1 0,0 1,0 4,0 O Li 2,1 Zr 0,9 Al 0,1 OCl4 2,0 4,3 Example 44 Li Zr Sc 0 3 Cl - - 0,1 0,1 0,0 1,0 4,0 O Li 2,1 Zr 0,9 Sc 0,1 OCl4 2,1 4,4 Example 45 Li Zr La 0 3 Cl - - 0,1 0,1 0,0 1,0 4,0 O Li 2,1 Zr 0,9 La 0,1 OCl4 2,3 4,8 Table 7 TO 2+a AND 1-b+α G b D c X d 0 ≤ b ≤ 0.5, -0.3 ≤ α ≤ 0.3, 0.01 ≤ c ≤ 3, 0.1 ≤ d ≤ 6.1 Fulfillment of formula (1) Solid electrolyte Ionic conductivity (mS cm -1 ) Discharge capacity (mAh) A E G D Value of G X a b α c d Example 46 Li Zr Ce 0 3 Cl - - 0,1 0,1 0,0 1,0 4,0 O Li 2,1 Zr 0,9 Ce 0,1 OCl4 2,2 4,6 Example 47 Li Zr Pr 0 3 Cl - - 0,1 0,1 0,0 1,0 4,0 O Li 2,1 Zr 0,9 Pr 0,1 OCl4 2,1 4,4 Example 48 Li Zr Nd 0 3 Cl - - 0,1 0,1 0,0 1,0 4,0 O Li 2,1 Zr 0,9 Nd 0,1 OCl4 2,3 4,6 Example 49 Li Zr PM 0 3 Cl - - 0,1 0,1 0,0 1,0 4,0 O Li 2,1 Zr 0,9 Pm 0,1 OCl4 2,1 4,4 Example 50 Li Zr Sm 0 3 Cl - - 0,1 0,1 0,0 1,0 4,0 O Li 2,1 Zr 0,9 S m0,1 OCl4 2,3 4,7 Example 51 Li Zr Eu 0 3 Cl - - 0,1 0,1 0,0 1,0 4,0 O Li 2,1 Zr 0,9 EU 0,1 OCl4 2,1 4,4 Example 52 Li Zr Gd 0 3 Cl - - 0,1 0,1 0,0 1,0 4,0 O Li 2,1 Zr 0,9 Mr. 0,1 OCl4 2,0 4,3 Example 53 Li Zr Tb 0 3 Cl - - 0,1 0,1 0,0 1,0 4,0 O Li 2,1 Zr 0,9 Tb 0,1 OCl4 2,2 4,6 Example 54 Li Zr Dy 0 3 Cl - - 0,1 0,1 0,0 1,0 4,0 O Li 2,1 Zr 0,9 Those 0,1 OCl4 2,1 4,5 Example 55 Li Zr Ho 0 3 Cl - - 0,1 0,1 0,0 1,0 4,0 O Li 2,1 Zr 0,9 Cough 0,1 OCl4 2,0 4,3 Example 56 Li Zr Er 0 3 Cl - - 0,1 0,1 0,0 1,0 4,0 O Li 2,1 Zr 0,9 Is 0,l OCl4 2,0 4,4 Example 57 Li Zr Tm 0 3 Cl - - 0,1 0,1 0,0 1,0 4,0 O Li 2,1 Zr 0,9 Tm 0,1 OCl4 2,0 4,3 Example 58 Li Zr Yb 0 3 Cl - - 0,1 0,1 0,0 1,0 4,0 O Li 2,1 Zr 0,9 Yb 0,1 OCl4 2,3 4,6 Example 59 Li Zr Lu 0 3 Cl - - 0,1 0,1 0,0 1,0 4,0 O Li 2,1 Zr 0,9 Lu 0,1 OCl4 2,2 4,6 Example 60 Li Zr Si 0 4 Cl - - 0,0 0,1 0,0 0,2 5,6 O Li2Zr 0,9 Yes 0,1 The 0,2 Cl 5,6 2,2 4,6 Example 61 Li Zr Sn 0 4 Cl - - 0,0 0,1 0,0 1,0 4,0 O Li2Zr 0,9 Sn 0,1 OCl4 2,0 4,2 Example 62 Li Zr Nb 0 5 Cl - - -0,1 0,1 0,0 1,0 4,0 O Li 1,9 Zr 0,9 Nb 0,1 OCl4 2,0 4,3 Example 63 Li Zr Ta 0 5 Cl - - -0,1 0,1 0,0 1,0 4,0 O That 1,9 Zr 0,9 Of 0,1 OCl4 1,9 4,2 Example 64 Li Zr W 0 6 Cl - - -0,2 0,1 0,0 1,0 4,0 O Li 1,8 Zr 0,9 W 0,1 OCl4 1,8 4,1 Example 65 Li Zr - 0 - F - - 0,0 0,0 0,0 1,0 4,0 O Li2ZrOF4 1,5 3,6 Table 8 A 2+a E 1-b+α GBD c X d 0 ≤ b ≤ 0.5, -0.3 ≤ α ≤ 0.3, 0.01 ≤ c ≤ 3, 0.1 ≤ d ≤ 6.1 Fulfillment of formula (1) Solid electrolyte Ionic conductivity (mS cm -1 ) Discharge capacity (mAh) A E G D Value of G X a b α c d Example 66 Li Zr - 0 - Br - - 0,0 0,0 0,0 1,0 4,0 O Li2ZrOBr4 1,5 3,7 Example 67 Li Zr - 0 - I - - 0,0 0,0 0,0 1,0 4,0 O Li2ZrOI4 1,8 4,0 Example 68 Li Zr - 0 - Cl F - 0,0 0,0 0,0 1,0 4,0 O Li2ZrOCl3F 1,7 3,9 Example 69 Li Zr - 0 - Cl Br - 0,0 0,0 0,0 1,0 4,0 O Li2ZrOCl3Br 1,6 3,7 Example 70 Li Zr - 0 - Cl I - 0,0 0,0 0,0 1,0 4,0 O Li2ZrOCl3I 1,7 3,8 Example 71 Li Zr - 0 - F Br - 0,0 0,0 0,0 1,0 4,0 O Li2ZrOFBr3 1,6 3,7 Example 72 Li Zr - 0 - F I - 0,0 0,0 0,0 1,0 4,0 O Li2ZrOFI3 1,8 4,0 Example 73 Li Zr - 0 - Br I - 0,0 0,0 0,0 1,0 4,0 O Li2ZrOBr2I2 1,8 4,2 Example 74 Li Zr - 0 - Cl F Br 0,0 0,0 0,0 1,0 4,0 O Li2ZrOCl2FBr 1,7 3,7 Example 75 Li Zr - 0 - Cl F I 0,0 0,0 0,0 1,0 4,0 O Li2ZrOCl2FI 1,6 3,8 Example 76 Li Zr - 0 - Cl Br I 0,0 0,0 0,0 1,0 4,0 O Li2ZrOCl2BrI 1,6 3,7 Example 77 Li Zr - 0 - F Br I 0,0 0,0 0,0 1,0 4,0 O Li2ZrOFBrI2 1,5 3,7 Example 78 Li Zr - See - Cl - - 0,0 0,0 0,0 1,0 4,0 O Li2ZrSeCl4 2,2 4,7 Example 79 Li Zr - The - Cl - - 0,0 0,0 0,0 1,0 4,0 O Li2ZrTeCl4 1,5 3,5 Example 80 Li Zr - 0 - Cl - - 0,0 0,0 0,0 1,0 4,0 O Li2ZrOCl4+Li2O 2,3 4,7 Example 81 Li Zr - 0 - Cl - - 0,0 0,0 0,0 1,0 4,0 O Li2ZrOCl4+LiCl 2,4 4,7 Example 82 Li Zr - 0 - Cl - - 0,0 0,0 0,0 1,0 4,0 O Li2ZrOCl4+ZrO2 2,5 4,7 Example 83 Li Zr - 0 - Cl - - 0,0 0,0 0,0 1,0 4,0 O Li2ZrOCl4+ZrCl4 2,5 4,8 Example 84 Li Zr - 0 - Cl - - 0,0 0,0 0,0 1,0 4,0 O Li2ZrOCl4+CaO 2,3 4,6 Comparison example 1 Li Zr - - - Cl - - 0,0 0,0 0,0 0,0 6,0 - Li2ZrCl6 0,3 2,1 (Measurement of ionic conductivities)

[0117] Each of the solid electrolytes of Example 1 to Example 84 and Comparative Example 1 was placed in a compression molding die and compression molded at a pressure of 373 MPa, thereby obtaining test specimens.

[0118] Specifically, resin mounts with a diameter of 10 mm and upper and lower punches with a diameter of 9.99 mm were manufactured. The upper and lower punches were made of die steel (SKD material). The lower punch was inserted into the resin mount, and each of the solid electrolytes from Example 1 to Example 84 and Comparative Example 1 (110 mg) was injected into it from above. The upper punch was placed on the solid electrolyte. The resin mount with the upper and lower punches inserted into it is referred to as the set below. The set was placed in a press, and the solid electrolyte was molded at a pressure of 373 MPa. This set was removed from the press.

[0119] Two stainless steel discs and two Teflon (registered trademark) discs were prepared, each with a diameter of 50 mm and a thickness of 5 mm, respectively. The stainless steel discs and Teflon (registered trademark) discs each had four screw holes. The stainless steel discs and Teflon (registered trademark) discs were placed on top of and underneath the set, and the set was pressurized by screwing screws through the four screw holes and tightening the screws.

[0120] Specifically, a laminate consisting of the stainless steel disc, the TEFLON (registered trademark) disc, the set, the TEFLON (registered trademark) disc, and the stainless steel disc was pressed together with screws in that order to create a device for measuring ionic conductivity. Screw holes were provided on the side surfaces of the upper and lower dies, into which screws were screwed. The screws were screwed into the upper and lower dies and used as connections for measuring ionic conductivity.

[0121] The ionic conductivity of each test specimen, which was included in the set in the ionic conductivity measuring device, was then measured. The ionic conductivity was measured with a potentiostat equipped with a frequency response analyzer using an electrochemical impedance measurement method. The ionic conductivity was measured in a frequency range of 7 MHz to 0.1 Hz under conditions where the amplitude was 10 mV and the temperature was 30°C. The results are shown in Tables 5 to 8. [Production of solid electrolyte batteries]

[0122] Solid electrolyte batteries containing a solid electrolyte layer composed of each of the solid electrolytes from Example 1 to Example 84 and Comparative Example 1 were each manufactured according to a method described below. The solid electrolyte batteries were manufactured in a glove box in which an argon atmosphere with a dew point of -70°C or lower was created. Furthermore, charge and discharge tests were conducted according to a method to be described below, and the discharge capacities were measured.

[0123] First, lithium cobalt oxide (LiCoO2), each of the solid electrolytes from Example 1 to Example 84 and Comparative Example 1, and carbon black were weighed in a ratio of 81:16:3 (by weight) and mixed in an agate mortar; thus, a positive electrode mixture was prepared. Next, graphite, each of the solid electrolytes from Example 1 to Example 84 and Comparative Example 1, and carbon black were weighed in a ratio of 67:30:3 (by weight) and mixed in an agate mortar; thus, a negative electrode mixture was prepared.

[0124] The lower die was inserted into the resin holder, and each of the solid electrolytes from Example 1 to Example 84 and Comparative Example 1 (110 mg) was injected into the resin holder from above. The upper die was placed on top of the solid electrolyte. The set was placed in a press, and the solid electrolyte was molded at a pressure of 373 MPa. The set was removed from the press, and the upper die was removed.

[0125] Each of the positive electrode mixtures (39 mg) was injected onto the (pellet-shaped) solid electrolyte in the resin holder. The upper punch was placed on the positive electrode mixture, and the set was placed in the press machine and molded at a pressure of 373 MPa. The set was then removed, turned over, and the lower punch was removed. Each of the negative electrode mixtures (20 mg) was injected onto the solid electrolyte (pellet), the lower punch was placed on the negative electrode mixture, and the set was placed in the press machine and molded at a pressure of 373 MPa.

[0126] As described above, battery elements consisting of the positive electrode, solid electrolyte, and negative electrode were fabricated in the resin mold. Screws were inserted into the screw holes on the sides of the upper and lower dies to serve as charging and discharging terminals.

[0127] An aluminum laminate material was used as the outer casing to seal the battery cells. This was a laminate material composed of PET (12), Al (40), and PP (50), in that order. PET stands for polyethylene terephthalate, and PP stands for polypropylene. The numerical values ​​in parentheses indicate the thickness (unit: µm) of the individual layers. This aluminum laminate material was cut to A4 size and folded in the middle of the long side so that PP formed the inner side.

[0128] Aluminum foils (4 mm wide, 40 mm long, and 100 µm thick) were used as positive electrode terminals. Nickel foils (4 mm wide, 40 mm long, and 100 µm thick) were also used as negative electrode terminals. Acid-modified PP was wrapped around each of these external terminals (the positive electrode terminals and the negative electrode terminals), and the external terminals were thermally bonded to the outer casings. This was intended to improve the seal between the external terminal and the outer casing.

[0129] The positive electrode terminal and the negative electrode terminal were placed approximately in the middle of the two facing sides of the folded aluminum laminate material, sandwiched by the aluminum laminate material, and heat-sealed. The assembly was then inserted into the outer casing, and the screw on the side surface of the upper die and the positive electrode terminal in the outer casing were connected with a lead to electrically connect the positive electrode and the positive electrode terminal. Furthermore, the screw on the side surface of the lower die and the negative electrode terminal in the outer casing were connected with a lead to electrically connect the negative electrode and the negative electrode terminal. Afterward, an opening portion of the outer casing was heat-sealed to form a solid electrolyte battery.

[0130] The charging and discharging tests were conducted in a constant-temperature chamber (25°C). The C-rate notation is used below to represent the charging and discharging current. nC (mA) represents the current that can charge and discharge the nominal capacity (mAh) for 1 / n (h). For example, for a battery with a nominal capacity of 70 mAh, a current of 0.05C is 3.5 mA (calculation formula: 70 × 0.05 = 3.5). Similarly, a current of 0.2C is 14 mA, and a current of 2C is 140 mA. The solid-electrolyte batteries were charged with a constant current / constant voltage (CCCV) up to 4.2 V at 0.2C. Charging was stopped when the current reached 1 / 20C. During discharge, the solid electrolyte batteries were discharged to 3.0 V at 0.2 C. The results are shown in Tables 5 to 8.

[0131] As shown in Table 5 to Table 8, the solid electrolytes of Example 1 to Example 84 all had sufficiently high ionic conductivity compared to the solid electrolyte of Comparative Example 1. Furthermore, all solid electrolyte batteries having a solid electrolyte layer composed of the solid electrolytes of Example 1 to Example 84 had sufficiently large discharge capacity compared to the solid electrolyte of Comparative Example 1. Explanation of reference symbols 1 Positive electrode 1A positive electrode current collector 1B Positive electrode mixed layer 2 Negative electrode 2A negative electrode current collector 2B Negative electrode mixed layer 3 Solid electrolyte layer 10 solid electrolyte batteries

Claims

[1] Solid electrolyte comprising a compound composed of: an alkali metal; at least one metal element with a valence of 1 to 6; an element of group XVII of the periodic table and an element of group XVI of the periodic table and is represented by the following formula (1), A2+aE1−b+αGbDcXd (In formula (1), A is an element selected from the group consisting of Li, K, and Na, E is at least one tetravalent element selected from the group consisting of Zr, Hf, Ti, and Sn, G is at least one element selected from the group consisting of B, Si, Mg, Ca, Sr, Cs, Ba, Y, Al, Sc, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Cu, Au, Pb, Bi, In, Sn, Sb, Nb, Ta, and W, D is at least one element selected from the group consisting of O, Se, and Te, X is at least one element selected from the group consisting of F, Cl, Br, and I, a is -2b in a case where G is a hexavalent element, a is -b in a case where G is a pentavalent element, a is zero in a case where G is a tetravalent element or G is not included, a is b in a case, where G is a trivalent element, a is 2b in a case where G is a divalent element, and a is 3b in a case where G is a monovalent element, b is 0 to 0.5, α is -0.3 to 0.3, c is 0,01 to 3 and d is 0.1 to 6.1). [2] The solid electrolyte according to claim 1, wherein in the compound represented by formula (1), G is a monovalent element. [3] The solid electrolyte according to claim 1, wherein in the compound represented by formula (1), G is a divalent element. [4] The solid electrolyte according to claim 1, wherein in the compound represented by formula (1), G is a trivalent element. [5] The solid electrolyte according to claim 1, wherein in the compound represented by formula (1), G is a tetravalent element. [6] The solid electrolyte according to claim 1, wherein in the compound represented by formula (1), G is a pentavalent element. [7] The solid electrolyte according to claim 1, wherein in the compound represented by formula (1), G is a hexavalent element. [8] The solid electrolyte according to any one of claims 1 to 7, wherein in the compound represented by formula (1), X is F. [9] The solid electrolyte according to any one of claims 1 to 7, wherein in the compound represented by formula (1), X is Cl. [10] The solid electrolyte according to any one of claims 1 to 7, wherein in the compound represented by formula (1), X is Br. [11] The solid electrolyte according to any one of claims 1 to 7, wherein in the compound represented by formula (1), XI is. [12] The solid electrolyte according to any one of claims 1 to 11, wherein in the compound represented by formula (1), DO is D. [13] The solid electrolyte according to any one of claims 1 to 11, wherein in the compound represented by formula (1), D is Se. [14] The solid electrolyte according to any one of claims 1 to 11, wherein in the compound represented by formula (1), D is Te. [15] The solid electrolyte according to claim 1, wherein in the compound represented by formula (1), A is Li, E is Zr, DO is O, and X is Cl. [16] The solid electrolyte according to claim 1, wherein in the compound represented by formula (1), A is Li, E is Zr, DO is D, and XI is X. [17] Solid electrolyte according to one of claims 1 to 16, further comprising 0.1 to 1.0 mass% of at least one compound selected from the group consisting of: A2O (A is an element selected from the group consisting of Li, K and Na); AX (A is an element selected from the group consisting of Li, K and Na, and X is at least one element selected from the group consisting of F, Cl, Br and I); EO2 (E is at least one tetravalent element selected from the group consisting of Zr, Hf, Ti and Sn); EX4 (E is at least one tetravalent element selected from the group consisting of Zr, Hf, Ti and Sn, and X is at least one element selected from the group consisting of F, Cl, Br and I) and GO n(G is at least one element selected from the group consisting of B, Si, Mg, Ca, Sr, Cs, Ba, Y, Al, Sc, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Eu, Tm, Yb, Lu, Cu, Ag, Au, Pb, Bi, In, Sn, Sb, Nb, Ta and W, and n is 0.5 in a case where G is a monovalent element, n is 1 in a case where G is a divalent element, n is 1.5 in a case where G is a trivalent element, n is 2 in a case where G is a tetravalent element, n is 2.5 in a case where G is a pentavalent element, and n is 3 in a case where G is a hexavalent element). [18] A solid electrolyte layer comprising: the solid electrolyte according to any one of claims 1 to 17, [19] A solid electrolyte battery comprising: a solid electrolyte layer; a positive electrode and a negative electrode, wherein at least one of the solid electrolyte layer, the positive electrode and the negative electrode contains the solid electrolyte according to any one of claims 1 to 17. [20] Solid electrolyte battery, comprising: a solid electrolyte layer; a positive electrode and a negative electrode, wherein the solid electrolyte layer contains the solid electrolyte according to any one of claims 1 to 17.

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