SOLID IONIC CONDUCTOR COMPOUND, SOLID ELECTROLYTE CONTAINING THE SAME, ELECTROCHEMICAL CELL CONTAINING THE SAME, AND METHOD FOR MANUFACTURING THE SAME

Abstract

To provide a solid ion conductor compound, a solid electrolyte including the solid ion conductor compound, an electrochemical cell including the solid ion conductor compound and a method of preparing the solid ion conductor compound.SOLUTION: There are provided: a solid ion conductor compound represented by Chemical Formula 1 and having an argyrodite-type crystal structure; a solid electrolyte including the solid ion conductor compound; an electrochemical cell including the solid ion conductor compound; and a method of preparing the solid ion conductor compound. [Chemical Formula 1] LixM1vPSyM2wM3z In the Chemical Formula 1, M1 is at least one metal element selected from Group 1 to Group 15 of the periodic table, except Li, M2 is SOn, M3 is at least one element selected from Group 17 of the periodic table, and 4≤x≤8, 0≤v<1, 3≤y≤7, 0<w<2, 0≤z≤2 and 1.5≤n≤5.SELECTED DRAWING: Figure 1A

Description

Technical Field

[0001] The present invention relates to a solid ion conductor compound, a solid electrolyte containing the same, a lithium battery containing the same, and a method for manufacturing the same.

Background Art

[0002] An all-solid-state lithium battery includes a solid electrolyte as an electrolyte. Since the all-solid-state lithium battery does not contain a flammable organic solvent, it has excellent stability.

[0003] Conventional solid electrolyte materials are not sufficiently stable against lithium metal. In addition, the lithium ion conductivity of conventional solid electrolytes is lower than that of liquid alternatives.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The problem to be solved by the present invention is to provide a solid ion conductor compound having improved lithium ion conductivity, oxidation stability, and air stability by having a new composition.

[0005] The problem to be solved by the present invention is also to provide a solid electrolyte containing the solid ion conductor compound.

[0006] The problem to be solved by the present invention is also to provide an electrochemical cell containing the solid ion conductor compound.

[0007] The problem to be solved by the present invention is also to provide a method for manufacturing the solid ion conductor.

Means for Solving the Problems

[0008] According to one aspect, a solid ion conductor compound represented by the following Chemical Formula 1 and having an al-dilaurite type crystal structure is provided: [Chemical Formula 1] Li x M1 v PS y M2 w M3 z In the above chemical formula 1, M1 is one or more metal elements other than Li selected from Groups 1 to 15 of the periodic table, M2 is SO n and M3 is one or more elements selected from Group 17 of the periodic table, 4 ≦ x ≦ 8, 0 ≦ v < 1, 3 ≦ y ≦ 7, 0 < w < 2, 0 ≦ z ≦ 2, and 1.5 ≦ n ≦ 5.

[0009] According to another aspect, a solid electrolyte containing the solid ion conductor compound as described above is provided.

[0010] According to still another aspect, a positive electrode layer including a positive electrode active material layer, a negative electrode layer including a negative electrode active material layer, and an electrolyte layer disposed between the positive electrode layer and the negative electrode layer, are provided, and an electrochemical cell in which the positive electrode active material layer and the electrolyte layer contain the solid ion conductor compound as described above is provided.

[0011] According to still another aspect, a lithium transition metal oxide, a transition metal sulfide, a lithium transition metal sulfide, or a combination thereof, and the solid ion conductor compound as described above disposed on the surface of the lithium transition metal oxide, the transition metal sulfide, or the lithium transition metal sulfide, are provided to form a protected positive electrode active material.

[0012] According to still another aspect, a compound containing lithium, one or more compounds containing a metal element other than Li selected from Groups 1 to 15 of the periodic table, a compound containing phosphorus (P), and SO nContacting a compound containing (1.5 ≦ n ≦ 5) with a compound selectively containing a Group 17 element of the periodic table to provide a mixture; Heat-treating the mixture in an inert atmosphere to provide a solid ion conductor compound. A method for producing a solid ion conductor compound is provided.

Advantages of the Invention

[0013] According to the present invention, by including a solid ion conductor compound with improved lithium ion conductivity and stability against lithium metal, an electrochemical cell having improved stability and cycle characteristics is provided.

Brief Description of the Drawings

[0014]

Figure 1A

Figure 1B

Figure 1C

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0015] Various embodiments are illustrated in the accompanying drawings. However, the inventive concept can be embodied in many other forms and is not to be construed as limited to the embodiments described herein. Rather, those embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art. Like reference numerals refer to like elements.

[0016] When a component is referred to as being "on" another component, it can be understood that it is also directly above the other component and that other components may intervene therebetween. In contrast, when a component is referred to as being "directly on" another component, no component intervenes therebetween.

[0017] Terms such as "first", "second", and "third" are also used herein to describe various components, elements, regions, layers, and / or sections, but those components, elements, regions, layers, and / or sections are not limited by those terms. Those terms are used to distinguish one component, element, region, layer, or section from another component, element, region, layer, or section. Thus, the first component, element, region, layer, or section described below may also be referred to as the second component, element, region, layer, or section without departing from the teachings of this specification.

[0018] The terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the inventive concept. The singular forms used in this application are intended to include the plural forms as well, unless the content clearly dictates otherwise. "At least one" is not to be construed as being limited to the singular. As used herein, the term "and / or" includes any and all combinations of one or more of the listed items. The terms "comprising" and / or "comprises" used in the detailed description specify the presence of the stated features, regions, integers, steps, operations, components, and / or elements, and do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, components, elements, and / or groups thereof.

[0019] Spatially relative terms such as "lower", "lower side", "lower part", "upper", "upper side", "upper part" are also used to easily describe the relationship of one component or feature to another component or feature. It is understood that spatially relative terms are intended to include different orientations of the device when additionally used or operated in the directions illustrated in the drawings. For example, if the device in the drawing is turned upside down, a component described as "lower" or "lower part" of another component or feature will be oriented "above" the other component or feature. Thus, the exemplary term "lower" can encompass either the up or down direction. The device can also be arranged in other directions (rotated 90 degrees or rotated in other directions), and the spatially relative terms used herein are to be interpreted accordingly.

[0020] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Also, terms defined as in a commonly used dictionary are to be interpreted as having a meaning consistent with their meaning in the context of the relevant art and the content of this disclosure, and are not to be interpreted in an idealized or overly formalized sense.

[0021] For exemplary embodiments, reference is made to cross-sectional views which are schematic illustrations of idealized embodiments, and which are described herein. As such, for example, variations from the illustrated shapes can be expected as a result of, for example, manufacturing techniques and / or tolerances. Accordingly, the embodiments described herein are not to be construed as being limited to the particular shapes of regions as illustrated herein, but include, for example, shape deviations resulting from manufacturing. For example, regions that are illustrated or described as being flat can typically have rough and / or non-linear features. Additionally, sharp corners illustrated are also rounded. Accordingly, regions illustrated in the drawings are essentially schematic in nature, and their shapes are not intended to illustrate the exact shape of a region nor to limit the scope of the claims.

[0022] "Group" means a group of the Periodic Table according to the group classification system of the International Union of Pure and Applied Chemistry (IUPAC) groups 1-18.

[0023] Although specific embodiments have been described, at present, alternatives, modifications, variations, improvements, and substantial equivalents that are not anticipated or cannot be anticipated by the applicant or a person skilled in the art may arise. Accordingly, the claims that are filed and may be amended are intended to include all such alternatives, modifications, variations, improvements, and substantial equivalents.

[0024] As used herein, "azirodite", "azide structure" or "azirodite-type structure" means a compound having a crystal structure that is isostructural with airodite, Ag8GeS6. As used herein, the term "metal element" includes metals and metalloids.

[0025] In the following, solid ion conductor compounds, solid electrolytes containing them, electrochemical cells containing them, and methods for producing the solid ion conductor compounds according to one or more exemplary embodiments will be described in more detail.

[0026] [Solid Ion Conductor Compound] A compound having ionic conductivity according to an embodiment, that is, a solid ion conductor compound, is represented by the following Chemical Formula 1 and has an argyrodite-type crystal structure: [Chemical Formula 1] Li x M1 v PS y M2 w M3 z

[0027] In Chemical Formula 1, M1 is one or more metal elements other than Li selected from Groups 1 to 15 of the periodic table, M2 is SO n and M3 is one or more elements selected from Group 17 of the periodic table, where 4 ≦ x ≦ 8, 0 ≦ v < 1, 3 ≦ y ≦ 7, 0 < w < 2, 0 ≦ z ≦ 2, and 1.5 ≦ n ≦ 5, or 5 < x < 8, 0 < v < 1, 4 < y < 7, 0 < w < 2, 0 < z < 2, and 1.5 < n < 5. For example, 5 ≦ x ≦ 8, 0 ≦ v < 1, 4 ≦ y ≦ 7, 0 < w < 2, 0 ≦ z ≦ 2, and 1.5 ≦ n ≦ 5, or 5 < x < 8, 0 < v < 1, 4 < y < 7, 0 < w < 2, 0 < z < 2, and 1.5 < n < 5. For example, 5 ≦ x ≦ 7, 0 ≦ v < 1, 4 ≦ y ≦ 6, 0 < w < 2, 0 ≦ z ≦ 2, and 1.5 ≦ n ≦ 5. For example, 5.4 ≦ x ≦ 7, 0 ≦ v < 1, 4.5 ≦ y ≦ 6, 0 < w < 2, 0.2 ≦ z ≦ 1.8, and 1.5 ≦ n ≦ 5, or 5.4 < x < 7, 0 < v < 1, 4.5 < y < 6, 0 < w < 2, 0.2 < z < 1.8, and 1.5 < n < 5.

[0028] The compound represented by Chemical Formula 1 is a crystalline compound having an argyrodite-type crystal structure. In the crystal structure, by including SO4 to be substituted in part of the sulfur (S) sites, the ionic conductivity of lithium ions can be improved and the activation energy can be reduced within the compound. For example, by arranging other ions having a larger ionic radius than sulfur ions in part of the sulfur (S) sites included in the solid ion conductor compound represented by Chemical Formula 1, the crystal lattice volume can be increased. Due to the increase in the volume of the crystal lattice, the movement of lithium ions within the crystal lattice becomes easier. Also, by arranging SO4 containing oxygen atoms, which are superior in oxidation stability and / or air stability compared to sulfur atoms, in part of the sulfur (S) sites included in the solid ion conductor compound represented by Chemical Formula 1, the structural stability of the compound can be improved.

[0029] Also, the compound represented by Chemical Formula 1 can improve the ionic conductivity of lithium ions and reduce the activation energy within the compound by including a metal and / or a metalloid to be substituted in part of the lithium sites in the crystal structure. For example, by arranging other ions having an ionic radius similar to or larger than that of lithium ions while having the same oxidation number as lithium in part of the lithium sites included in the solid ion conductor compound represented by Chemical Formula 1, the crystal lattice volume increases. Due to the increase in the volume of the crystal lattice, the movement of lithium ions within the crystal lattice becomes easier. Also, for example, due to electrical neutrality, by arranging ions having a larger oxidation number than lithium ions, that is, ions with an oxidation number of 2 or more, in part of the lithium sites included in the solid ion conductor compound represented by Chemical Formula 1, part of the lithium sites also become vacant sites. The presence of vacant sites within the crystal lattice makes the movement of lithium ions within the crystal lattice easier.

[0030] In the solid ion conductor compound represented by Chemical Formula 1, for example, 0 ≦ v / (x + v) < 0.2 and 0 < w / (y + w) < 0.2; 0 ≦ v / (x + v) < 0.15 and 0 < w / (y + w) < 0.15, or 0 ≦ v / (x + v) < 0.1 and 0 < w / (y + w) < 0.1 are also applicable.

[0031] In the solid ion conductor compound represented by Chemical Formula 1, for example, 0 ≦ v / (x + v) < 0.2 and 0 < w / (y + w + z) < 0.2, 0 ≦ v / (x + v) < 0.15 and 0 < w / (y + w + z) < 0.15, 0 ≦ v / (x + v) < 0.1 and 0 < w / (y + w + z) < 0.1 are also applicable.

[0032] In the solid ion conductor compound represented by Chemical Formula 1, for example, SO n is also S4O6, S3O6, S2O3, S2O4, S2O5, S2O6, S2O7, S2O8, SO4, SO5, or a combination thereof. SO n is, for example, also a divalent anion. SO n 2- is, for example, S4O6 2- , S3O6 2- , S2O3 2- , S2O4 2- , S2O5 2- , S2O6 2- , S2O7 2- , S2O8 2- , SO4 2- , SO5 2- or a combination thereof.

[0033] In the solid ion conductor compound represented by Chemical Formula 1, for example, 0 ≦ v / (x + v) < 0.08 and 0 < w / (y + w) < 0.08, and it may contain SO4.

[0034] In the solid ion conductor compound represented by Chemical Formula 1, for example, 0 ≦ v / (x + v) < 0.08 and 0 < w / (y + w + z) < 0.08, and it may contain SO4.

[0035] In the solid ion conductor compound represented by Chemical Formula 1, for example, M1 may include Na, K, Mg, Ag, Cu, Hf, In, Ti, Pb, Sb, Fe, Zr, Zn, Cr, B, Sn, Ge, Si, Ta, Nb, V, Ga, Al, As, or a combination thereof.

[0036] In the solid ion conductor compound represented by Chemical Formula 1, for example, M1 may include Na, K, Mg, Ag, Cu, or a combination thereof.

[0037] In the solid ion conductor compound represented by Chemical Formula 1, for example, M3 may include F, Cl, Br, I, or a combination thereof.

[0038] The solid ion conductor compound represented by Chemical Formula 1 is also, for example, a solid ion conductor compound represented by the following Chemical Formula 2: [Chemical Formula 2] Li 7-m×v-z M1 v PS 6-w-z M2 w M3 z

[0039] In Chemical Formula 2, M1 is one or more metal elements other than Li selected from Groups 1 to 15 of the periodic table, m is the oxidation number of M1, M2 is SO n and M3 is an element selected from Group 17 of the periodic table, where 0 ≦ v < 1, 0 < w < 2, 0 ≦ z ≦ 2, 1.5 ≦ n ≦ 5, and 1 ≦ m ≦ 2. For example, m is 1 or 2.

[0040] Suitable monovalent cations selected from Groups 1 and 11 of the periodic table are also, for example, Na, K, Rb, Cs, Cu, Ag.

[0041] The solid ion conductor compound represented by Chemical Formula 1 is also, for example, a solid electrolyte compound represented by the following Chemical Formula 3 or 4: [Chemical Formula 3] (Li 1-d M1d ) a P(S 1-e M2 e ) b M3 c [Chemical Formula 4] (Li 1-d M1 d ) a Li fc P(S 1+fc-e M2 e ) b (M3 1-f M2 f ) c

[0042] In Chemical Formulas 3 and 4, M1 is Na, K, Mg, Ag, Cu, Hf, In, Ti, Pb, Sb, Fe, Zr, Zn, Cr, B, Sn, Ge, Si, Ta, Nb, V, Ga, Al, As, or a combination thereof; M2 is SO4; M3 is one or more elements selected from Group 17 of the periodic table; 5 ≦ a ≦ 7, 4 ≦ b ≦ 6, 0 ≦ c ≦ 2; 0 < d ≦ 0.08, 0 < e ≦ 0.08, 0 < f ≦ 0.08, 0 < e + f ≦ 0.08. In one embodiment, the solid ion conductor is a compound of Chemical Formula 3 or Chemical Formula 4. In one embodiment, M3 is one Group 17 element.

[0043] In the solid ion conductor compound represented by Chemical Formula 4, for example, when M2 is substituted at the S site, a part of Cl is precipitated as LiCl.

[0044] The solid ion conductor compound represented by Chemical Formula 1 is also, for example, a solid ion conductor compound represented by the following Chemical Formula 5 or 6: [Chemical Formula 5] (Li 1-d M1 d ) a P(S 1-e (SO4) e ) b M3 c [Chemical Formula 6] (Li 1-d M1 d ) aLi fc P(S 1+fc-e (SO4) e ) b (M3 1-f (SO4) f ) c

[0045] In Chemical Formulas 5 and 6, M1 is Na, K, Mg, Ag, Cu, or a combination thereof; M3 is one or more elements selected from Group 17 of the periodic table; 5 ≤ a ≤ 7, 4 ≤ b ≤ 6, 0 ≤ c ≤ 2; 0 < d < 0.08, 0 < e < 0.08, 0 < f < 0.08, 0 < e + f < 0.08. In one embodiment, M3 is one Group 17 element.

[0046] In the solid ion conductor compound represented by Chemical Formula 6, for example, when SO4 substitutes at the S site, a part of Cl precipitates as LiCl.

[0047] The solid ion conductor compound represented by Chemical Formula 1 is also, for example, a solid ion conductor compound represented by the following Chemical Formulas 5a to 6e: [Chemical Formula 5a] (Li 1-d Na d ) a P(S 1-e (SO4) e ) b M3 c [Chemical Formula 5b] (Li 1-d K d ) a P(S 1-e (SO4) e ) b M3 c [Chemical Formula 5c] (Li 1-d Mg d ) a P(S 1-e (SO4) e ) b M3 c [Chemical Formula 5d] (Li 1-dAg d ) a P(S 1-e (SO4) e ) b M3 c [Chemical formula 5e] (Li 1-d Cu d ) a P(S 1-e (SO4) e ) b M3 c [Chemical formula 6a] (Li 1-d Na d ) a Li fc P(S 1+fc-e (SO4) e ) b (M3 1-f (SO4) f ) c [Chemical formula 6b] (Li 1-d K d ) a Li fc P(S 1+fc-e (SO4) e ) b (M3 1-f (SO4) f ) c [Chemical formula 6c] (Li 1-d Mg d ) a Li fc P(S 1+fc-e (SO4) e ) b (M3 1-f (SO4) f ) c [Chemical formula 6d] (Li 1-d Ag d ) a Li fc P(S 1-e (SO4) e ) b (M3 1-f (SO4) f ) c [Chemical formula 6e] (Li 1-d Cu d ) a Li fc P(S 1+fc-e (SO4) e ) b (M3 1-f (SO4) f ) c

[0048] In Chemical Formulas 5a to 6e, M3 is one or more elements selected from Group 17 of the periodic table, 5 ≤ a ≤ 7, 4 ≤ b ≤ 6, 0 ≤ c ≤ 2, 0 < d ≤ 0.06, 0 < e ≤ 0.06, 0 < f ≤ 0.06, and 0 < e + f ≤ 0.06. In one embodiment, M3 is one Group 17 element.

[0049] In the solid ion conductor compound represented by Chemical Formulas 6a to 6e, for example, when SO4 substitutes for the S site, a part of Cl precipitates as LiCl.

[0050] The solid ion conductor compound represented by Chemical Formula 1 is also, for example, a solid ion conductor compound represented by the following chemical formula: (Li 1-d Cu d ) a P(S 1-e (SO4) e ) b F c 、(Li 1-d Cu d ) a P(S 1-e (SO4) e ) b Cl c 、(Li 1-d Cu d ) a P(S 1-e (SO4) e ) b Br c 、(Li 1-d Cu d ) a P(S 1-e (SO4) e ) b I c 、 (Li 1-d Cu d ) a Li fc P(S 1+fc-e (SO4) e ) b (F 1-f (SO4) f ) c 、(Li 1-d Cu d ) a Li fc P(S 1+fc-e (SO4) e ) b (Cl 1-f (SO4) f ) c 、(Li 1-d Cu d ) a Li fc P(S 1+fc-e (SO4) e ) b (Br 1-f (SO4) f ) c 、(Li 1-d Cu d ) a Li fc P(S 1+fc-e (SO4) e ) b (I 1-f (SO4) f ) c 、 (Li 1-d Na d ) a P(S 1-e (SO4) e ) b F c 、(Li 1-d Na d ) a P(S 1-e (SO4) e ) b Cl c 、(Li 1-d Na d ) a P(S 1-e (SO4) e ) b Br c 、(Li 1-d Nad ) a P(S 1-e (SO4) e ) b I c 、 (Li 1-d Na d ) a Li fc P(S 1+fc-e (SO4) e ) b (F 1-f (SO4) f ) c 、(Li 1-d Na d ) a Li fc P(S 1+fc-e (SO4) e ) b (Cl 1-f (SO4) f ) c 、(Li 1-d Na d ) a Li fc P(S 1+fc-e (SO4) e ) b (Br 1-f (SO4) f ) c 、(Li 1-d Na d ) a Li fc P(S 1+fc-e (SO4) e ) b (I 1-f (SO4) f ) c 、 (Li 1-d K d ) a P(S 1-e (SO4) e ) b F c 、(Li 1-d K d ) a P(S 1-e (SO4) e ) b Cl c 、(Li 1-d K d ) aP(S 1-e (SO4) e ) b Br c 、(Li 1-d K d ) a P(S 1-e (SO4) e ) b I c 、 (Li 1-d K d ) a Li fc P(S 1+fc-e (SO4) e ) b (F 1-f (SO4) f ) c 、(Li 1-d K d ) a Li fc P(S 1+fc-e (SO4) e ) b (Cl 1-f (SO4) f ) c 、(Li 1-d K d ) a Li fc P(S 1+fc-e (SO4) e ) b (Br 1-f (SO4) f ) c 、(Li 1-d K d ) a Li fc P(S 1+fc-e (SO4) e ) b (I 1-f (SO4) f ) c 、 (Li 1-d Mg d ) a P(S 1-e (SO4) e ) b F c 、(Li 1-d Mg d ) a P(S 1-e (SO4)e ) b Cl c 、(Li 1-d Mg d ) a P(S 1-e (SO4) e ) b Br c 、(Li 1-d Mg d ) a P(S 1-e (SO4) e ) b I c 、 (Li 1-d Mg d ) a Li fc P(S 1+fc-e (SO4) e ) b (F 1-f (SO4) f ) c 、(Li 1-d Mg d ) a Li fc P(S 1+fc-e (SO4) e ) b (Cl 1-f (SO4) f ) c 、(Li 1-d Mg d ) a Li fc P(S 1+fc-e (SO4) e ) b (Br 1-f (SO4) f ) c 、(Li 1-d Mg d ) a Li fc P(S 1+fc-e (SO4) e ) b (I 1-f (SO4) f ) c 、 (Li 1-d Ag d ) a P(S 1-e (SO4) e ) bF c 、(Li 1-d Ag d ) a P(S 1-e (SO4) e ) b Cl c 、(Li 1-d Ag d ) a P(S 1-e (SO4) e ) b Br c 、(Li 1-d Ag d ) a P(S 1-e (SO4) e ) b I c 、 (Li 1-d Ag d ) a Li fc P(S 1+fc-e (SO4) e ) b (F 1-f (SO4) f ) c 、(Li 1-d Ag d ) a Li fc P(S 1+fc-e (SO4) e ) b (Cl 1-f (SO4) f ) c 、(Li 1-d Ag d ) a Li fc P(S 1+fc-e (SO4) e ) b (Br 1-f (SO4) f ) c 、(Li 1-d Ag d ) a Li fc P(S 1+fc-e (SO4) e ) b (I 1-f (SO4) f ) c ; Combinations of two or more of them may be used.

[0051] In the above chemical formula, a, b, c, d, e, and f are independently selected from each other, 5 ≤ a ≤ 7, 4 ≤ b ≤ 6, 0 ≤ c ≤ 2, 0 < d ≤ 0.06, 0 < e < 0.06, 0 < f < 0.06, and 0 < e + f < 0.06.

[0052] The solid ion conductor compound represented by Chemical Formula 1 is also, for example, a solid ion conductor compound represented by the following Chemical Formula 7: [Chemical Formula 7] Li 7-p×v-u-z M4 v M5 u PS 6-w-z M2 w M3 z

[0053] In Chemical Formula 7, M4 is a metal element selected from Groups 2 to 15 of the periodic table, p is the oxidation number of M4, M2 is SO n and M3 is an element selected from Group 17 of the periodic table, M5 is a metal element other than Li selected from Group 1 of the periodic table, is a monovalent cation, 0 ≤ v < 1, 0 ≤ u < 1, 0 < w < 2, 0 ≤ z ≤ 2, 1.5 ≤ n ≤ 5, and 1 ≤ p ≤ 2. For example, p is 1 or 2. In one embodiment, M4 is one or more elements selected from Groups 2 to 15 of the periodic table. In one embodiment, M3 is one or more elements selected from Group 17 of the periodic table.

[0054] In the solid ion conductor compound represented by Chemical Formula 7, for example, M4 may include Cu, Ag, Mg, Hf, In, Ti, Pb, Sb, Fe, Zr, Zn, Cr, B, Sn, Ge, Si, Ta, Nb, V, Ga, Al, As, or a combination thereof. In the solid ion conductor compound represented by Chemical Formula 7, for example, M5 may include Na, K, Rb, Cs, or a combination thereof.

[0055] Suitable monovalent cations selected from Groups 2 and 11 of the periodic table include, for example, Cu and Ag. Suitable divalent cations selected from Groups 2 and 11 of the periodic table include, for example, Ca, Zn, Mg, and Fe. The solid ionic conductor compound represented by Chemical Formula 1 is also, for example, a solid ionic conductor compound represented by the following Chemical Formula 8: [Chemical formula 8] Li 7-z PS 6-w-z M2 w M3 z

[0056] In the formula 8, M2 is SO n M3 is an element selected from Group 17 of the periodic table, and 0 <w<2、0≦z≦2及び1.5≦n≦5である。一具現例において、M3は、周期律表17族のうちから選択された1以上の元素である。

[0057] The solid ionic conductor compound represented by Chemical Formula 1 is also, for example, a solid ionic conductor compound represented by Chemical Formula 9 or 10 below: [Chemical formula 9] Li a+fc P(S 1+fc-e M2 e ) b (M3 1-f M2 f ) c [Chemical formula 10] Li a P(S 1-e M2 e ) b M3 c

[0058] In the formulas 9 and 10, M2 is SO4, M3 is one or more elements selected from Group 17 of the periodic table, and 5≦a≦7, 4≦b≦6, 0≦c≦2, and 0 <e≦0.08、0<f≦0.08、0<e+f≦0.08である。一具現例において、M3は、周期律表17族のうちから選択された1つの元素である。化学式9によって表される固体イオン伝導体化合物において、例えば、SサイトにM2が置換されることにより、Clの一部がLiClとして析出される。

[0059] The solid ionic conductor compound represented by Chemical Formula 1 is also, for example, a solid ionic conductor compound represented by the following Chemical Formula 11 or 12: [Chemical formula 11] Li a+fc P(S 1+fc-e (SO4) e ) b (M3 1-f (SO4) f ) c [Chemical formula 12] Li a P(S 1-e (SO4) e ) b M3 c

[0060] In the formulas 11 and 12, M3 is one or more elements selected from Group 17 of the periodic table, and 5≦a≦7, 4≦b≦6, 0≦c≦2; <e<0.08、0<f<0.08、0<e+f<0.08である。一具現例において、M3は、周期律表17族のうちから選択された1以上の元素である。一具現例において、M3、は周期律表17族のうちから選択される1つの17族元素である。

[0061] In the solid ionic conductor compound represented by Chemical Formula 11, for example, SO4 is substituted at the S site, causing part of Cl to precipitate as LiCl.

[0062] The solid ionic conductor compound represented by Chemical Formula 1 is also, for example, a solid ionic conductor compound represented by the following chemical formula: Li a+fc P(S 1+fc-e (SO4) e ) b (F 1-f (SO4) f ) c , Li a+fc P(S 1+fc-e (SO4) e ) b (Cl 1-f (SO4) f ) c , Li a+fc P(S 1+fc-e (SO4) e ) b (Br 1-f (SO4) f ) c , Li a+fc P(S 1+fc-e (SO4) e ) b (I 1-f (SO4) f ) c , Li a P(S 1-e (SO4) e ) b F c , Li a P(S 1-e (SO4) e ) b Cl c , Li a P(S 1-e (SO4) e ) b Br c , Li a P(S 1-e (SO4) e ) b I c

[0063] In the formula, a, b, c, d, e, and f are independently selected and are 5≦a≦7, 4≦b≦6, and 0≦c≦2; <e<0.06、0<f<0.06、0<e+f<0.06である。

[0064] The solid ion conductor compound represented by Chemical Formula 1 provides improved lithium ion conductivity. The solid ion conductor compound represented by Chemical Formula 1 provides an ion conductivity of 1.0 mS / cm or more, 1.5 mS / cm or more, 2.0 mS / cm or more, 2.5 mS / cm or more, 3.0 mS / cm or more, 3.5 mS / cm or more, 4.0 mS / cm or more, or 5.0 mS / cm or more at room temperature, for example, at about 25°C. The solid ion conductor compound represented by Chemical Formula 1 provides an ion conductivity of 1.0 to 500 mS / cm, 1.5 to 400 mS / cm, 2.0 to 300 mS / cm, 2.5 to 200 mS / cm, 3.0 to 150 mS / cm, 3.5 to 100 mS / cm, 4.0 to 100 mS / cm, or 5.0 to 100 mS / cm at room temperature, for example, at about 25°C. Therefore, in an electrochemical cell including a positive electrode, a negative electrode, and the solid ion conductor compound represented by Chemical Formula 1 disposed between the positive electrode and the negative electrode, ion transfer between the positive electrode and the negative electrode can be effectively performed, and the internal resistance between the positive electrode and the negative electrode can be reduced. The ion conductivity can be measured using the DC polarization method. As an alternative, the ion conductivity can be measured using the complex impedance method.

[0065] The solid ion conductor compound represented by Chemical Formula 1 can have an ion conductivity retention rate of 70% or more, 75% or more, or 80% or more, for example, 70% to 99.9%, or 80% to 99%, after 10 days in a dry condition of an air atmosphere having a dew point of less than -60°C. The ion conductivity retention rate is also represented, for example, by the following Mathematical Formula 1. In the following Mathematical Formula 1, the ion conductivity of the initial solid ion conductor compound means the ion conductivity of the solid ion conductor compound before storage under dry conditions. The ion conductivity retention rate can be measured by the method disclosed in Evaluation Example 3.

[0066] [Mathematical Formula 1] Ion conductivity retention rate [%] = [Ion conductivity of solid ionic conductor compound after 10 days / Initial ionic conductivity of solid ionic conductor compound] × 100

[0067] The solid ionic conductor compound represented by Chemical Formula 1 may belong to a cubic crystal system, more specifically, to the F-43m space group. The solid ionic conductor compound represented by Chemical Formula 1 may also be an argyrodite-type sulfide having an argyrodite-type crystal structure. The solid ionic conductor compound represented by Chemical Formula 1 has an argyrodite-type crystal structure in which SO4 is present in some of the sulfur (S) sites. 2- The solid ion conductor compound represented by Chemical Formula 1 contains oxygen atoms substituted with anions, which can simultaneously provide improved lithium ion conductivity, improved oxidation resistance to lithium metal, and improved atmospheric stability. In addition, the solid ion conductor compound represented by Chemical Formula 1 has an argyrodite-type crystal structure in which M1 is present at a portion of the lithium site. + Cationic element, M1 2+ Cation elements and M1 3+ Substitution of one or more of the cationic elements can simultaneously provide improved lithium ion conductivity and electrochemical stability relative to lithium metal.

[0068] Referring to FIG. 1C, the solid ion conductor compound represented by Chemical Formula 1 includes, for example, in an XRD (X-ray diffraction) spectrum using CuKα rays, a first peak at a diffraction angle 2θ = 30.1° ± 0.5° and a second peak at a diffraction angle 2θ = 31.5° ± 0.5°. Except that M2 is changed to S, a compound having the same composition as the solid ion conductor compound represented by Chemical Formula 1 includes, in an XRD spectrum using CuKα rays, a third peak at a diffraction angle 2θ = 30.1° ± 0.5° and a fourth peak at a diffraction angle 2θ = 31.5° ± 0.5°. The positions of the first peak and the second peak are downshifted by 0.01° or more, 0.02° or more, 0.03° or more, or 0.04° or more, respectively, compared to the third peak and the fourth peak. Such a downshift of the peak is because, compared with sulfur (S), SO4 having a larger ionic radius is substituted, increasing the interplanar distance of the crystal lattice. The solid ion conductor compound having such an increased interplanar distance of the crystal lattice can provide improved oxidation resistance and air stability.

[0069] Referring to FIG. 1B, the solid ion conductor compound represented by Chemical Formula 1 may further include, for example, in an XRD spectrum using CuKα rays, a peak corresponding to LiM3 reprecipitated by M2 at a diffraction angle 2θ = 35.0° ± 1.0°. Such LiM3 is, for example, LiCl. The solid ion conductor compound having such an additional peak can provide improved oxidation resistance and air stability.

[0070] In another aspect, the disclosed compound of Chemical Formula 1 can be used to provide a protected positive electrode active material. The positive electrode active material may include a lithium transition metal oxide, a transition metal sulfide, a lithium transition metal sulfide, or a combination thereof. The compound of Chemical Formula 1 can also be disposed on the surface of the positive electrode active material. The compound of Chemical Formula 1 can also be disposed on the surface of the positive electrode active material, for example, as a layer. The thickness of the layer can be, for example, 1 nm to 1,000 nm, or 10 nm to 100 nm.

[0071] [Solid electrolyte] A solid electrolyte according to another embodiment includes a solid ion conductor compound represented by Chemical Formula 1. The solid electrolyte may be, for example, made of the compound of Chemical Formula 1 or may be in the form of a layer including the compound of Chemical Formula 1. The layer may be disposed between a positive electrode and a negative electrode, disposed on a positive electrode active material, or disposed on a negative electrode active material. By including such a solid ion conductor compound, the solid electrolyte may have high ionic conductivity and high chemical stability. A solid electrolyte including the solid ion conductor compound represented by Chemical Formula 1 may provide improved stability against air and electrochemical stability against lithium metal. Therefore, the solid ion conductor compound represented by Chemical Formula 1 may also be used, for example, as a solid electrolyte in an electrochemical cell.

[0072] The solid electrolyte may further include a second solid electrolyte in addition to the solid ion conductor compound represented by Chemical Formula 1. For example, the second solid electrolyte may further include a conventional sulfide-based solid electrolyte and / or an oxide-based solid electrolyte. Examples of the second solid electrolyte further include Li2O-Al2O3-TiO2-P2O5 (LATP), LISICON (lithium super ionic conductor), LIPON (Li 3-y PO 4-x N x , 0 <y<3、0<x<4)、thio‐LISICON(Li 3.25 Ge0.25 P 0.75 S4), Li2S, Li2S-P2S5, Li2S-SiS2, Li2S-GeS2, Li2S-B2S5, and Li2S-Al2S5, but are not necessarily limited thereto, and any of them is possible as long as it is used in the relevant technical field.

[0073] The solid electrolyte may be in powder form or in the form of a monolithic body. The monolithic solid electrolyte may be in the form of, for example, pellets, sheets, thin films, etc., but is not necessarily limited thereto, and can have various forms depending on the application.

[0074] [Electrochemical cell] An electrochemical cell according to another embodiment includes a positive electrode layer including a positive electrode active material layer, a negative electrode layer including a negative electrode active material layer, and an electrolyte layer disposed between the positive electrode layer and the negative electrode layer, wherein the positive electrode active material layer and / or the electrolyte layer includes a solid ion conductor compound represented by Chemical Formula 1. By including the solid ion conductor compound represented by Chemical Formula 1, the lithium ion conductivity and the stability with respect to lithium metal of the electrochemical cell are improved.

[0075] The electrochemical cell may be, for example, an all-solid-state secondary battery, a secondary battery containing a liquid electrolyte, or a lithium-air battery, but is not necessarily limited thereto, and any of them is possible as long as it is an electrochemical cell that can be used in the relevant technical field.

[0076] Hereinafter, the all-solid-state secondary battery will be described in more detail.

[0077] [All-solid-state secondary battery: Type 1] The all-solid-state secondary battery may include a solid ion conductor compound represented by Chemical Formula 1.

[0078] The all-solid-state secondary battery may include, for example, a positive electrode layer including a positive electrode active material layer, a negative electrode layer including a negative electrode active material layer, and an electrolyte layer disposed between the positive electrode layer and the negative electrode layer, and the positive electrode active material layer and / or the electrolyte layer may include a solid ion conductor compound represented by Chemical Formula 1.

[0079] An all-solid-state secondary battery according to an embodiment may be prepared as follows.

[0080] (solid electrolyte layer) First, a solid electrolyte layer is prepared.

[0081] The solid electrolyte layer can be produced by mixing the solid ion conductor compound represented by Chemical Formula 1 with a binder and drying the mixture, or by rolling the powder of the solid ion conductor compound represented by Chemical Formula 1 into a certain shape under a pressure of 1 to 10 tons. The solid ion conductor compound represented by Chemical Formula 1 is used as the solid electrolyte.

[0082] The solid electrolyte may have an average particle size of, for example, 0.5 μm to 20 μm, 0.5 μm to 15 μm, or 1 μm to 10 μm. When the solid electrolyte has such an average particle size, the binding strength during the sintering process may be improved, and the ionic conductivity and life characteristics of the solid electrolyte particles may be improved.

[0083] The thickness of the solid electrolyte layer is 10 μm to 200 μm, 20 μm to 150 μm, or 30 μm to 100 μm, which ensures a sufficient lithium ion migration rate and results in high ionic conductivity.

[0084] In addition to the solid ion conductor compound represented by Chemical Formula 1, the solid electrolyte layer may further include a solid electrolyte such as a conventional sulfide-based solid electrolyte and / or an oxide-based solid electrolyte.

[0085] Conventional sulfide-based solid electrolytes (e.g., containing sulfide) may include, for example, lithium sulfide, silicon sulfide, phosphorus sulfide, boron sulfide, or a combination thereof. Conventional sulfide-based solid electrolyte particles may include Li2S, P2S5, SiS2, GeS2, B2S3, or a combination thereof. Conventional sulfide-based solid electrolyte particles may also be Li2S or P2S5. Conventional sulfide-based solid electrolyte particles are known to have higher lithium ion conductivity than other inorganic compounds. For example, conventional sulfide-based solid electrolytes include Li2S and P2S5. When the sulfide solid electrolyte material constituting the conventional sulfide-based solid electrolyte includes Li2S-P2S5, the molar ratio of Li2S to P2S5 may range, for example, from about 50:50 to about 90:10. Furthermore, Li3PO4, halogen compounds, Li 2+2x Zn 1-x GeO4("LISICON", 0 <x<1)、Li 3+y PO 4-x N x ("LIPON", 0 <x<4、0<y<3)、Li 3.25 Ge 0.25 P 0.75 Inorganic solid electrolytes prepared by adding S4 ("thio-LISICON"), Li2O-Al2O3-TiO2-P2O5 ("LATP"), etc. to inorganic solid electrolytes of Li2S-P2S5, SiS2, GeS2, B2S3, or combinations thereof are also used as conventional sulfide solid electrolytes. Non-limiting examples of conventional sulfide solid electrolyte materials include Li2S-P2S5, Li2S-P2S5-LiX (X is a halogen), Li2S-P2S5-Li2O, Li2S-P2S5-Li2O-LiI, Li2S-SiS2, Li2S-SiS2-LiI, Li2S-SiS2-LiBr, Li2S-SiS2-LiCl, Li2S-SiS2-B2S3-LiI, Li2S-SiS2-P2S5-LiI, Li2S-B2S3, Li2S-P2S5-Z m S n (m and n are positive numbers, and Z is Ge, Zn, or G), Li2S-GeS2, Li2S-SiS2-Li3PO4, and Li2S-SiS2-Li p MO q(In the above chemical formula, p and q are positive numbers, and M is P, Si, Ge, B, Al, Ga, or In). In this regard, the conventional sulfide-based solid electrolyte material is a starting material for the sulfide-based solid electrolyte material (e.g., Li2 S , P2S5, etc.) by melt quenching method, mechanical milling method, etc. A calcination step is also carried out after the treatment.

[0086] The binder contained in the solid electrolyte layer may be, for example, but not limited to, styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polyvinyl alcohol, etc. Any binder used in the art may be used. The binder for the solid electrolyte layer may be the same as or different from the binders for the positive electrode layer and the negative electrode layer.

[0087] (positive electrode layer) Next, the positive electrode layer is prepared.

[0088] The positive electrode layer can be produced by forming a positive electrode active material layer containing a positive electrode active material on a current collector. The positive electrode active material has an average particle size of, for example, 2 μm to 10 μm.

[0089] The positive electrode active material may be any material commonly used in secondary batteries without limitation. For example, lithium transition metal oxides, lithium transition metal sulfides, and transition metal sulfides may be used. For example, one or more of composite oxides of lithium and a metal selected from cobalt, manganese, nickel, and combinations thereof may be used. Specific examples thereof include Li a A 1-b B' b D2 (wherein the formula is 0.90≦a≦1.8 and 0≦b≦0.5), Li a E 1-b B' b O 2-c Dc (In the chemical formula, 0.90 ≦ a ≦ 1.8, 0 ≦ b ≦ 0.5, 0 ≦ c ≦ 0.05), LiE 2-b B’ b O 4-c D c (In the chemical formula, 0 ≦ b ≦ 0.5, 0 ≦ c ≦ 0.05), Li a Ni 1-b-c Co b B’ c D α (In the chemical formula, 0.90 ≦ a ≦ 1.8, 0 ≦ b ≦ 0.5, 0 ≦ c ≦ 0.05, 0 < α ≦ 2), Li a Ni 1-b-c Co b B’ c O 2-α F’ α (In the chemical formula, 0.90 ≦ a ≦ 1.8, 0 ≦ b ≦ 0.5, 0 ≦ c ≦ 0.05, 0 < α < 2), Li a Ni 1-b-c Co b B’ c O 2-α F’2 (In the chemical formula, 0.90 ≦ a ≦ 1.8, 0 ≦ b ≦ 0.5, 0 ≦ c ≦ 0.05, 0 < α < 2), Li a Ni 1-b-c Mn b B’ c D α (In the chemical formula, 0.90 ≦ a ≦ 1.8, 0 ≦ b ≦ 0.5, 0 ≦ c ≦ 0.05, 0 < α ≦ 2), Li a Ni 1-b-c Mn b B’ c O 2-α F’ α (In the chemical formula, 0.90 ≦ a ≦ 1.8, 0 ≦ b ≦ 0.5, 0 ≦ c ≦ 0.05, 0 < α < 2), Li a Ni 1-b-c Mn b B’ c O 2-α F’2 (In the chemical formula, 0.90 ≦ a ≦ 1.8, 0 ≦ b ≦ 0.5, 0 ≦ c ≦ 0.05, 0 < α < 2), Li a Ni b E c G dO2 (in the above chemical formula, 0.90 ≦ a ≦ 1.8, 0 ≦ b ≦ 0.9, 0 ≦ c ≦ 0.5, 0.001 ≦ d ≦ 0.1), Li a Ni b Co c Mn d G e O2 (in the above chemical formula, 0.90 ≦ a ≦ 1.8, 0 ≦ b ≦ 0.9, 0 ≦ c ≦ 0.5, 0 ≦ d ≦ 0.5, 0.001 ≦ e ≦ 0.1), Li a NiG b O2 (in the above chemical formula, 0.90 ≦ a ≦ 1.8, 0.001 ≦ b ≦ 0.1), Li a CoG b O2 (in the above chemical formula, 0.90 ≦ a ≦ 1.8, 0.001 ≦ b ≦ 0.1), Li a MnG b O2 (in the above chemical formula, 0.90 ≦ a ≦ 1.8, 0.001 ≦ b ≦ 0.1), Li a Mn2G b O4 (in the above chemical formula, 0.90 ≦ a ≦ 1.8, 0.001 ≦ b ≦ 0.1), QO2; QS2, LiQS2, V2O5, LiV2O2, LiI’O2, LiNiVO4, Li 3-f J2(PO4)3 (0 ≦ f ≦ 2), Li 3-f Fe2(PO4)3 (0 ≦ f ≦ 2), A compound represented by any one of the chemical formulas of LiFePO4 can be used. In the above chemical formula, A is Ni, Co, Mn, or a combination thereof, B' is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof, D is O, F, S, P, or a combination thereof, E is Co, Mn, or a combination thereof, F' is F, S, P, or a combination thereof, G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof, Q is Ti, Mo, Mn, or a combination thereof, I' is Cr, V, Fe, Sc, Y, or a combination thereof, and J is V, Cr, Mn, Co, Ni, Cu, or a combination thereof.

[0090] The positive electrode active material is, for example, LiCoO2, LiMn x O2x (x=1,2), LiNi 1-x Mn x O 2x (0 <x<1)、LiNi 1-x-y Co x Mn y O2 (0≦x≦0.5, 0≦y≦0.5), LiNi 1-x-y Co x Al y Examples of suitable coating layers include O2 (0≦x≦0.5, 0≦y≦0.5), LiFePO4, TiS2, FeS2, TiS3, and FeS3. Compounds with a coating layer added to the surface of such compounds can also be used, as can mixtures of the aforementioned compounds with coating layers. Examples of coating layers added to the surface of such compounds include oxides of the coating elements, hydroxides of the coating elements, oxyhydroxides of the coating elements, oxycarbonates of the coating elements, and hydroxycarbonates of the coating elements. Compounds forming such coating layers can be amorphous or crystalline. Examples of coating elements included in the coating layer include Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr, or mixtures thereof. The coating layer formation method is selected within a range that does not adversely affect the physical properties of the positive electrode active material. Examples of suitable coating methods include spray coating and dipping. The specific coating method is well known to those skilled in the art, and therefore a detailed description thereof will be omitted.

[0091] The positive electrode active material contains, for example, the lithium salt of the transition metal oxide having a layered rock salt type structure in the lithium transition metal oxide described above. The "layered rock salt type structure" refers to, for example, a cubic rock salt type structure. <111> In this structure, oxygen atomic layers and metal atomic layers are regularly arranged in the direction of the crystal structure, and each atomic layer forms a two-dimensional plane. The "cubic rock salt structure" refers to a sodium chloride (NaCl) type structure, which is a type of crystal structure, and specifically refers to a structure in which face-centered cubic lattices (fcc) formed by cations and anions are shifted from each other by about half the ridge of a unit lattice. Lithium transition metal oxides having such a layered rock salt structure include, for example, LiNi x Co y Al z O2(NCA) or LiNi x Co y Mn z O2(NCM)(0 <x<1、0<y<1、0<z<1、x+y+z=1)のような三元系リチウム遷移金属酸化物である。該正極活物質が層状岩塩型構造を有する三元系リチウム遷移金属酸化物を含む場合、全固体二次電池のエネルギー密度及び熱安定性がさらに向上する。

[0092] The positive electrode active material is also covered with a coating layer as described above. The coating layer may be any known coating layer for positive electrode active materials in all-solid-state secondary batteries. The coating layer may be, for example, Li2O-ZrO2 (LZO).

[0093] When the positive electrode active material contains nickel (Ni) as a ternary lithium transition metal oxide such as NCA or NCM, the capacity density of the all-solid-state secondary battery can be increased and metal elution from the positive electrode active material can be reduced in a charged state, resulting in improved cycle characteristics of the all-solid-state secondary battery.

[0094] The shape of the positive electrode active material is, for example, a particle shape such as a true spherical shape or an elliptical spherical shape. The particle size of the positive electrode active material is not particularly limited and is within the range applicable to the positive electrode active materials of conventional all-solid-state secondary batteries. The content of the positive electrode active material in the positive electrode layer is also not particularly limited and is within the range applicable to the positive electrode layers of conventional all-solid-state secondary batteries. In the positive electrode active material layer, the content of the positive electrode active material is, for example, also 50 to 95% by weight.

[0095] The positive electrode active material layer may further contain a solid ion conductor compound represented by Chemical Formula 1.

[0096] The positive electrode active material layer may contain a binder. The binder is, for example, styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, etc.

[0097] The positive electrode active material layer may contain a conductive agent. The conductive agent is, for example, graphite, carbon black, acetylene black, Ketjen black, carbon fiber, metal powder, etc.

[0098] In addition to the aforementioned positive electrode active material, solid electrolyte, binder, and conductive agent, the positive electrode active material layer may further contain additives such as fillers, coating agents, dispersants, and ion conductivity assisting agents.

[0099] As the fillers, coating agents, dispersants, ion conductivity assisting agents, etc. contained in the positive electrode active material layer, generally, known materials used for the electrodes of all-solid-state secondary batteries can be used.

[0100] As the positive electrode current collector, for example, a plate or foil made of aluminum (Al), indium (In), copper (Cu), magnesium (Mg), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), germanium (Ge), lithium (Li), or an alloy thereof is used. The positive electrode current collector can be omitted.

[0101] The positive electrode current collector may further include a carbon layer disposed on one or both sides of the metal substrate. The additional carbon layer disposed on the metal substrate prevents the metal of the metal substrate from being corroded by the solid electrolyte contained in the positive electrode layer, thereby reducing the interfacial resistance between the positive electrode active material layer and the positive electrode current collector. The carbon layer may have a thickness of, for example, 1 μm to 5 μm. If the carbon layer is too thin, it is difficult to completely block contact between the metal substrate and the solid electrolyte. If the carbon layer is too thick, the energy density of the all-solid-state secondary battery will decrease. The carbon layer may include amorphous carbon, crystalline carbon, etc.

[0102] (negative electrode layer) Next, the negative electrode layer is prepared.

[0103] The negative electrode layer may be fabricated by the same method as the positive electrode layer, except that a negative electrode active material is used instead of a positive electrode active material, and may be fabricated by forming a negative electrode active material layer containing the negative electrode active material on a negative electrode current collector.

[0104] The negative electrode active material layer may additionally contain a solid ion conductor compound represented by Chemical Formula 1 above.

[0105] The negative electrode active material can be lithium metal, a lithium metal alloy, or a combination thereof.

[0106] In addition to lithium metal, a lithium metal alloy, or a combination thereof, the negative electrode active material layer may further contain a conventional negative electrode active material. The conventional negative electrode active material may include, for example, one or more selected from the group consisting of metals alloyable with lithium, transition metal oxides, non-transition metal oxides, and carbon-based materials. Metals alloyable with lithium include, for example, Ag, Si, Sn, Al, Ge, Pb, Bi, SbSi-Y alloy (where Y is an alkali metal, alkaline earth metal, Group 13 element, Group 14 element, Group 15 element, Group 16 element, transition metal, rare earth element, or a combination thereof, and not Si), Sn-Y alloy (where Y is an alkali metal, alkaline earth metal, Group 13 element, Group 14 element, Group 15 element, Group 16 element, transition metal, rare earth element, or a combination thereof, and not Sn). Examples of the element Y also include Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Tc, Re, Bh, Fe, Pb, Ru, Os, Hs, Rh, Ir, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, Sn, In, Ti, Ge, P, As, Sb, Bi, S, Se, Te, Po, or a combination thereof. The transition metal oxide is also, for example, lithium titanate, vanadium oxide, or lithium vanadate. The non-transition metal oxide is, for example, SnO2, SiO x (0 < x < 2). The carbon-based material is also, for example, crystalline carbon, amorphous carbon, or a mixture thereof. The crystalline carbon is also graphite such as amorphous, plate-like, flaky, spherical, or fibrous natural graphite or artificial graphite, and the amorphous carbon is also soft carbon (low-temperature calcined carbon), hard carbon, mesophase pitch carbide, or calcined coke.

[0107] 2, an all-solid-state secondary battery 40 according to an embodiment includes a solid electrolyte layer 30, a positive electrode layer 10 disposed on one side of the solid electrolyte layer 30, and a negative electrode layer 20 disposed on the other side of the solid electrolyte layer 30. The positive electrode layer 30 includes a positive electrode active material layer 12 in contact with the solid electrolyte layer 30 and a positive electrode current collector 11 in contact with the positive electrode active material layer 12, and the negative electrode layer 20 includes a negative electrode active material layer 22 in contact with the solid electrolyte layer 30 and a negative electrode current collector 21 in contact with the negative electrode active material layer 22. The all-solid-state secondary battery 40 is completed, for example, by forming the positive electrode active material layer 12 and the negative electrode active material layer 22 on both sides of the solid electrolyte layer 30, and then forming the positive electrode current collector 11 and the negative electrode current collector 21 on the positive electrode active material layer 12 and the negative electrode active material layer 22, respectively. As an alternative, an all-solid-state secondary battery 40 is completed by sequentially stacking an anode active material layer 22, a solid electrolyte layer 30, a cathode active material layer 12, and a cathode current collector 11 on an anode current collector 21, for example.

[0108] [All-solid-state secondary battery: Type 2] 3 and 4, the all-solid-state secondary battery 1 includes, for example, a positive electrode layer 10 including a positive electrode active material layer 12 disposed on a positive electrode current collector 11, a negative electrode layer 20 including a negative electrode active material layer 22 disposed on a negative electrode current collector 21, and an electrolyte layer 30 disposed between the positive electrode layer 10 and the negative electrode layer 20, and the positive electrode active material layer 12 and / or the electrolyte layer 30 may include a solid ion conductor compound represented by Chemical Formula 1.

[0109] An all-solid-state secondary battery according to another embodiment may be prepared as follows.

[0110] The positive electrode layer and the solid electrolyte layer are manufactured in the same manner as in the above-described all-solid-state secondary battery.

[0111] (negative electrode layer) Next, the negative electrode layer is prepared.

[0112] 3 and 4, the negative electrode layer 20 includes a negative electrode current collector 21 and a negative electrode active material layer 22 disposed on the negative electrode current collector 21, and the negative electrode active material layer 22 includes, for example, a negative electrode active material and a binder.

[0113] The negative electrode active material contained in the negative electrode active material layer 22 has, for example, a particulate form. The average particle size of the particulate negative electrode active material is, for example, 4 μm or less, 3 μm or less, 2 μm or less, 1 μm or less, or 900 nm or less. The average particle size of the particulate negative electrode active material is, for example, 10 nm to 4 μm or less, 10 nm to 3 μm or less, 10 nm to 2 μm or less, 10 nm to 1 μm or less, or 10 nm to 900 nm or less. Having an average particle size within such a range of particle size makes it easier to reversibly absorb and / or desorb lithium during charging and discharging. The average particle size of the negative electrode active material is, for example, the median diameter (D50) measured using a laser particle size distribution analyzer.

[0114] The negative electrode active material contained in the negative electrode active material layer 22 includes, for example, one or more selected from a carbon-based negative electrode active material, a metal negative electrode active material, and a semi-metal negative electrode active material.

[0115] The carbon-based negative electrode active material is, in particular, amorphous carbon. Examples of amorphous carbon include, but are not limited to, carbon black (CB), acetylene black (AB), furnace black (FB), ketjen black (KB), and graphene. Any material classified as amorphous carbon in the art is acceptable. Amorphous carbon is carbon with no or very low crystallinity, and is distinguished from crystalline carbon or graphite-based carbon.

[0116] The metal negative electrode active material or the metalloid negative electrode active material includes, but is not necessarily limited to, one or more selected from the group consisting of gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn). Any material can be used as long as it is a metal negative electrode active material or a metalloid negative electrode active material that forms an alloy or a compound with lithium in the technical field. For example, nickel (Ni) does not form an alloy with lithium, so it is not the metal negative electrode active material.

[0117] The negative electrode active material layer 22 contains one kind of negative electrode active material among such negative electrode active materials, or a mixture of a plurality of different negative electrode active materials. For example, the negative electrode active material layer 22 contains only amorphous carbon, or contains one or more selected from the group consisting of gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn). As an alternative, the negative electrode active material layer 22 contains a mixture of amorphous carbon and one or more selected from the group consisting of gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn). The mixing ratio of the mixture of the amorphous carbon and gold or the like is, for example, 10:1 to 1:2, 5:1 to 1:1, or 4:1 to 2:1 as a weight ratio, but is not necessarily limited to such a range and is selected according to the required characteristics of the all-solid-state secondary battery 1. When the negative electrode active material has such a composition, the cycle characteristics of the all-solid-state secondary battery 1 are further improved.

[0118] The negative electrode active material included in the negative electrode active material layer 22 includes a mixture of first particles made of amorphous carbon and second particles made of a metal or semi-metal. Examples of the metal or semi-metal include gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn). Alternatively, the semi-metal may be a semiconductor. The content of the second particles is 8 to 60 wt %, 10 to 50 wt %, 15 to 40 wt %, or 20 to 30 wt %, based on the total weight of the mixture. By including the second particles in such a range, the cycle characteristics of the all-solid-state secondary battery 1 may be further improved.

[0119] The binder contained in the negative electrode active material layer 22 may be, for example, styrene-butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, vinylidene fluoride / hexafluoropropylene copolymer, polyacrylonitrile, polymethyl methacrylate, etc., but is not necessarily limited thereto, and any binder used in the relevant technical field may be used. The binder may be configured as a single binder or a plurality of different binders.

[0120] The inclusion of a binder in the negative electrode active material layer 22 stabilizes the negative electrode active material layer 22 on the negative electrode current collector 21. Furthermore, cracking of the negative electrode active material layer 22 is suppressed despite volume changes and / or relative position changes of the negative electrode active material layer 22 during charge / discharge cycles. For example, if the negative electrode active material layer 22 does not include a binder, the negative electrode active material layer 22 can be easily separated from the negative electrode current collector 21. When the negative electrode active material layer 22 is separated from the negative electrode current collector 21, the negative electrode current collector 21 comes into contact with the solid electrolyte layer 30 at the exposed portion of the negative electrode current collector 21, increasing the possibility of a short circuit. The negative electrode active material layer 22 is produced, for example, by applying a slurry, in which materials constituting the negative electrode active material layer 22 are dispersed, onto the negative electrode current collector 21 and drying the slurry. The inclusion of the binder in the negative electrode active material layer 22 allows stable dispersion of the negative electrode active material in the slurry. For example, when the slurry is applied onto the negative electrode current collector 21 by screen printing, clogging of the screen (for example, clogging due to aggregates of the negative electrode active material) can be suppressed.

[0121] The negative electrode active material layer 22 can further contain additives used in conventional all-solid-state secondary batteries 1, such as fillers, coating agents, dispersants, and ion-conducting auxiliary agents.

[0122] The thickness of the negative electrode active material layer 22 is, for example, 50% or less, 40% or less, 30% or less, 20% or less, 10% or less, or 5% or less of the thickness of the positive electrode active material layer 12. The thickness of the negative electrode active material layer 22 is, for example, 1 μm to 20 μm, 2 μm to 10 μm, or 3 μm to 7 μm. If the thickness of the negative electrode active material layer 22 is excessively thin, lithium dendrites formed between the negative electrode active material layer 22 and the negative electrode current collector 21 will cause the negative electrode active material layer 22 to collapse, making it difficult to improve the cycle characteristics of the all-solid-state secondary battery 1. If the thickness of the negative electrode active material layer 22 is excessively large, the energy density of the all-solid-state secondary battery 1 will decrease, and the internal resistance of the all-solid-state secondary battery 1 due to the negative electrode active material layer 22 will increase, making it difficult to improve the cycle characteristics of the all-solid-state secondary battery 1.

[0123] If the thickness of the negative electrode active material layer 22 is reduced, for example, the charge capacity of the negative electrode active material layer 22 also decreases. The charge capacity of the negative electrode active material layer 22 is, for example, 50% or less, 40% or less, 30% or less, 20% or less, 10% or less, 5% or less, or 2% or less of the charge capacity of the positive electrode active material layer 12. The charge capacity of the negative electrode active material layer 22 is, for example, 0.1% to 50%, 0.1% to 40%, 0.1% to 30%, 0.1% to 20%, 0.1% to 10%, 0.1% to 5%, or 0.1% to 2% of the charge capacity of the positive electrode active material layer 12. If the charge capacity of the negative electrode active material layer 22 is excessively small, the thickness of the negative electrode active material layer 22 becomes very thin, and therefore, during repeated charge and discharge processes, lithium dendrites formed between the negative electrode active material layer 22 and the negative electrode current collector 21 collapse the negative electrode active material layer 22, making it difficult to improve the cycle characteristics of the all-solid-state secondary battery 1. If the charge capacity of the negative electrode active material layer 22 is excessively increased, the energy density of the all-solid-state secondary battery 1 decreases and the internal resistance of the all-solid-state secondary battery 1 due to the negative electrode active material layer 22 increases, making it difficult to improve the cycle characteristics of the all-solid-state secondary battery 1.

[0124] The charge capacity of the positive electrode active material layer 12 is obtained by multiplying the charge capacity density (mAh / g) of the positive electrode active material by the mass of the positive electrode active material in the positive electrode active material layer 12. When multiple positive electrode active materials are used, the charge capacity density x mass value is calculated for each positive electrode active material, and the sum of these values is the charge capacity of the positive electrode active material layer 12. The charge capacity of the negative electrode active material layer 22 is calculated in the same manner. That is, the charge capacity of the negative electrode active material layer 22 is obtained by multiplying the charge capacity density (mAh / g) of the negative electrode active material by the mass of the negative electrode active material in the negative electrode active material layer 22. When multiple negative electrode active materials are used, the charge capacity density x mass value is calculated for each negative electrode active material, and the sum of these values is the capacity of the negative electrode active material layer 22. Here, the charge capacity densities of the positive electrode active material and the negative electrode active material are capacities estimated using an all-solid-state half-cell using lithium metal as the counter electrode. The charge capacity of the positive electrode active material layer 12 and the negative electrode active material layer 22 is directly measured by measuring the charge capacity using the all-solid-state half-cell. The charge capacity density is obtained by dividing the measured charge capacity by the mass of each active material. Alternatively, the charge capacity of the positive electrode active material layer 12 and the negative electrode active material layer 22 can also be the initial charge capacity measured during the first cycle charge.

[0125] Referring to FIG. 4, the all-solid-state secondary battery 1a may further include a metal layer 23 disposed between the negative electrode current collector 21 and the negative electrode active material layer 22. The metal layer 23 includes lithium or a lithium alloy. Thus, the metal layer 23 functions as a lithium reservoir. The lithium alloy may be, but is not limited to, a Li-Al alloy, a Li-Sn alloy, a Li-In alloy, a Li-Ag alloy, a Li-Au alloy, a Li-Zn alloy, a Li-Ge alloy, or a Li-Si alloy. Any lithium alloy known in the art may be used. The metal layer 23 may be made of one of these alloys, lithium, or a variety of alloys.

[0126] The thickness of the metal layer 23 is not particularly limited. For example, it may be 1 μm to 1,000 μm, 1 μm to 500 μm, 1 μm to 200 μm, 1 μm to 150 μm, 1 μm to 100 μm, or 1 μm to 50 μm. If the thickness of the metal layer 23 is excessively thin, it is difficult for the metal layer 23 to play the role of a lithium storage reservoir. If the thickness of the metal layer 23 is excessively thick, the mass and volume of the all-solid-state secondary battery 1 will increase, and the cycle characteristics may instead deteriorate. The metal layer 23 is, for example, also a metal foil having a thickness within such a range.

[0127] In the all-solid-state secondary battery 1a, the metal layer 23 is disposed, for example, between the negative electrode current collector 21 and the negative electrode active material layer 22 before assembling the all-solid-state secondary battery 1, or is precipitated between the negative electrode current collector 21 and the negative electrode active material layer 22 by charging after assembling the all-solid-state secondary battery 1. When the metal layer 23 is disposed between the negative electrode current collector 21 and the negative electrode active material layer 22 before assembling the all-solid-state secondary battery 1a, the metal layer 23 is a metal layer containing lithium and therefore acts as a lithium reservoir. For example, before assembling the all-solid-state secondary battery 1a, lithium foil is disposed between the negative electrode current collector 21 and the negative electrode active material layer 22. This further improves the cycle characteristics of the all-solid-state secondary battery 1a including the metal layer 23. When the metal layer 23 is precipitated by charging after assembling the all-solid-state secondary battery 1a, the all-solid-state secondary battery 1a does not include the metal layer 23 during assembly, and therefore the energy density of the all-solid-state secondary battery 1a is increased. For example, when charging the all-solid-state secondary battery 1, charging is performed beyond the charge capacity of the anode active material layer 22. That is, the anode active material layer 22 is overfilled. At the beginning of charging, lithium is absorbed into the anode active material layer 22. The anode active material contained in the anode active material layer 22 forms an alloy or a compound with lithium ions migrated from the cathode layer 10. If charging is performed beyond the capacity of the anode active material layer 22, for example, lithium is deposited on the back surface of the anode active material layer 22, i.e., between the anode current collector 21 and the anode active material layer 22, and the deposited lithium forms a metal layer corresponding to the metal layer 23. The metal layer 23 is a metal layer mainly composed of lithium (i.e., metallic lithium). Such a result can be achieved, for example, by configuring the anode active material contained in the anode active material layer 22 with a material that forms an alloy or a compound with lithium. During discharge, the lithium in the anode active material layer 22 and the metal layer 23, i.e., the metal layer, is ionized and migrates toward the cathode layer 10. Therefore, lithium can be used as the negative electrode active material in the all-solid-state secondary battery 1a. Furthermore, the negative electrode active material layer 22 covers the metal layer 23, and therefore serves as a protective layer for the metal layer 23 and also serves to suppress the precipitation and growth of lithium dendrites. Therefore, short circuits and capacity reductions of the all-solid-state secondary battery 1a are suppressed, and as a result, the cycle characteristics of the all-solid-state secondary battery 1a are improved.Furthermore, after the all-solid-state secondary battery 1a is assembled, when the metal layer 23 is disposed by charging, the negative electrode current collector 21, the negative electrode active material layer 22, and the region therebetween are Li-free regions that do not contain lithium (Li), for example, in the initial state or post-discharge state of the all-solid-state secondary battery 1a.

[0128] The negative electrode current collector 21 is made of, for example, a material that does not react with lithium, i.e., does not form any alloy or compound. Materials constituting the negative electrode current collector 21 include, but are not limited to, copper (Cu), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), and nickel (Ni), and any material commonly used as an electrode current collector in the art is acceptable. The negative electrode current collector 21 may be made of one of the aforementioned metals, or an alloy of two or more metals, or a coating material. The negative electrode current collector 21 is, for example, in the form of a plate or foil.

[0129] The all-solid-state secondary battery 1 may further include, for example, a thin film on the negative electrode current collector 21, the thin film including an element capable of forming an alloy with lithium. The thin film is disposed between the negative electrode current collector 21 and the negative electrode active material layer 22. The thin film includes, for example, an element capable of forming an alloy with lithium. The element capable of forming an alloy with lithium may be, but is not limited to, gold, silver, zinc, tin, indium, silicon, aluminum, or bismuth. Any element known in the art to be capable of forming an alloy with lithium may be used. The thin film may be composed of one of these metals or an alloy of multiple metals. By disposing the thin film on the negative electrode current collector 21, for example, the deposition morphology of the metal layer 23 deposited between the thin film and the negative electrode active material layer 22 may be further flattened, thereby further improving the cycle characteristics of the all-solid-state secondary battery 1.

[0130] The thickness of the thin film is, for example, 1 nm to 800 nm, 10 nm to 700 nm, 50 nm to 600 nm, or 100 nm to 500 nm. When the thickness of the thin film is less than 1 nm, it becomes difficult to exhibit the function of the thin film. If the thickness of the thin film is excessively thick, the thin film itself occludes lithium, the amount of lithium deposition in the negative electrode decreases, the energy density of the all-solid-state battery decreases, and the cycle characteristics of the all-solid-state secondary battery 1 deteriorate. The thin film can be disposed on the negative electrode current collector 21 by, for example, a vacuum evaporation method, a sputtering method, a plating method, etc., but is not necessarily limited to such a method, and in the technical field, any method capable of forming a thin film is possible.

[0131] According to another embodiment, a method for manufacturing a solid ion conductor compound includes contacting a compound containing lithium, a compound containing a metal element other than Li selected from Groups 1 to 15 of the periodic table, a compound containing phosphorus (P), and a compound containing SO n (1.5 ≦ n ≦ 5) to provide a mixture, and heat-treating the mixture in an inert atmosphere to provide a solid ion conductor compound. The solid ion conductor compound is, for example, a solid ion conductor compound represented by Chemical Formula 1.

[0132] The compound containing lithium includes a sulfide containing lithium. For example, lithium sulfide is mentioned.

[0133] The compound containing a metal element other than Li selected from Groups 1 to 15 of the periodic table includes an element selected from Groups 1 to 15 of the periodic table and a sulfide not containing Li. For example, copper sulfide, silver sulfide, sodium sulfide (Na2S), magnesium sulfide, potassium sulfide (K2S), etc. are mentioned.

[0134] The compound containing phosphorus (P) includes a sulfide containing phosphorus. For example, P2S5 is mentioned. A compound containing sulfur (S) can be additionally used in the mixture.

[0135] SO n Compounds containing (1.5 ≦ n ≦ 5) include SO n and include lithium salts containing the same. For example, Li2S4O6, Li2S3O6, Li2S2O3, Li2S2O4, Li2S2O5, Li2S2O6, Li2S2O7, Li2S2O8, Li2SO4, Li2SO5, etc. are mentioned. Compounds containing Group 17 elements include lithium salts containing Group 17 elements. For example, LiCl, LiF, LiBr, LiI are mentioned.

[0136] Such compounds can also be produced by bringing starting materials into contact in an appropriate amount, for example, in a stoichiometric amount, to form a mixture and subjecting the mixture to heat treatment. The contact may include milling or grinding such as ball milling.

[0137] A mixture of precursors mixed in a stoichiometric composition can be heat-treated in an inert atmosphere to produce a solid ion conductor compound.

[0138] The heat treatment is also carried out, for example, at 400 to 700 °C, 400 to 650 °C, 400 to 600 °C, 400 to 550 °C, or 400 to 500 °C. The heat treatment time is, for example, 1 to 36 hours, 2 to 30 hours, 4 to 24 hours, 10 to 24 hours, or 16 to 24 hours. The inert atmosphere is an atmosphere containing an inert gas. The inert gas is, for example, nitrogen, argon, but is not necessarily limited thereto, and any gas can be used as long as it is used as an inert gas in the art.

[0139] The inventive concept will be described in more detail through the following examples and comparative examples. However, the examples are for illustrative purposes only, and the scope of the inventive concept is not limited thereto.

[0140] (Production of Solid Ion Conductor Compound) Example 1: (Li 5.69 Cu 0.06 )P(S4.70 (SO4) 0.05 )Cl 1.25 Manufacturing In a glove box under an Ar atmosphere, a lithium precursor, Li2S, a phosphorus (P) precursor, P2S5, a chlorine (Cl) precursor, LiCl, a copper (Cu) precursor, Cu2S, and an SO4 precursor, Li2SO4, were mixed to obtain the desired composition (Li 5.69 Cu 0.06 )P(S 4.70 (SO4) 0.05 )Cl 1.25 The materials were combined in a stoichiometric ratio to obtain a solid ionic conductor. The mixture was then milled and mixed in a planetary ball mill containing zirconia (YSZ) balls in an Ar atmosphere at 100 rpm for 1 hour, and then milled and mixed at 800 rpm for 30 minutes. The resulting mixture was pressed under uniaxial pressure to prepare pellets approximately 10 mm thick and 13 mm in diameter. The pellets were covered with gold foil and placed in a carbon crucible, which was then vacuum-sealed using a quartz glass tube. The vacuum-sealed pellets were heated from room temperature to 500°C at a rate of 1.0°C / min in an electric furnace, heat-treated at 500°C for 12 hours, and then cooled to room temperature at a rate of 1.0°C / min to produce a solid ionic conductor compound.

[0141] The composition of the produced solid ionic conductor compound is (Li 5.69 Cu 0.06 )P(S 4.70 (SO4) 0.05 )Cl 1.25 (Ratio of substituted cation (Cu): 0.01, ratio of substituted anion (SO4): 0.01).

[0142] Example 2: (Li 5.69+b Cu 0.06 )P(S 4.75+b-a (SO4) a )(Cl 1.25-b (SO4) b ), (SO4) a+b =(SO4) 0.15, (0.05 <a<0.15、0<b<0.15、a+b=0.15)の製造 (Li 5.69 Cu 0.06 )P(S 4.60 (SO4) 0.15 )Cl 1.25 A solid ionic conductor compound was produced in the same manner as in Example 1, except that the stoichiometric mixing ratio of the starting materials was changed to satisfy the composition.

[0143] As can be seen from FIG. 1B, in the above composition, a part of Cl was reprecipitated in the form of LiCl, thereby obtaining a solid ionic conductor compound having the following composition:

[0144] The composition of the produced solid ionic conductor compound is (Li 5.69+b Cu 0.06 )P(S 4.75+b-a (SO4) a )(Cl 1.25-b (SO4) b ), (SO4) a+b =(SO4) 0.15 , (0.05 <a<0.15、0<b<0.15、a+b=0.15)であった。

[0145] Example 3: (Li 5.72 Cu 0.03 )P(S 4.725 (SO4) 0.025 )Cl 1.25 Manufacturing The desired composition (Li 5.72 Cu 0.03 )P(S 4.725 (SO4) 0.025 )Cl 1.25 A solid ionic conductor compound was prepared in the same manner as in Example 1, except that the stoichiometric mixing ratio of the starting materials was changed to obtain

[0146] The composition of the produced solid ionic conductor compound is (Li 5.72 Cu 0.03 )PS 4.725 (SO4) 0.025 Cl 1.25(Ratio of substituted cation (Cu): 0.005, ratio of substituted anion (SO4): 0.005).

[0147] Example 4: (Li 5.72 Na 0.03 )P(S 4.725 (SO4) 0.025 )Cl 1.25 Manufacturing The desired composition (Li 5.72 Na 0.03 )P(S 4.725 (SO4) 0.025 )Cl 1.25 A solid ionic conductor compound was prepared in the same manner as in Example 1, except that the stoichiometric mixing ratio of the starting materials was changed and NaS was used as the sodium precursor instead of the copper precursor.

[0148] The composition of the produced solid ionic conductor compound is (Li 5.72 Na 0.03 )P(S 4.725 (SO4) 0.025 )Cl 1.25 (Ratio of substituted cations (Na): 0.005, ratio of substituted anions (SO4): 0.005).

[0149] Example 5: Li 5.75 P(S 4.725 (SO4) 0.025 )Cl 1.25 Manufacturing The desired composition is Li 5.75 P(S 4.725 (SO4) 0.025 )Cl 1.25 A solid ionic conductor compound was prepared in the same manner as in Example 1, except that Cu2S was not added and the stoichiometric mixing ratio of the starting materials was changed so as to obtain

[0150] The composition of the produced solid ionic conductor compound is Li 5.75 P(S 4.725 (SO4) 0.025 )Cl 1.25(Ratio of substituted anion (SO4): 0.005).

[0151] Comparative example 1: Li 5.75 PS 4.75 Cl 1.25 Manufacturing The desired composition is Li 5.75 PS 4.75 Cl 1.25 A solid ionic conductor compound was prepared in the same manner as in Example 1, except that Cu2S and Li2SO4 were not added and the stoichiometric mixing ratio of the starting materials was changed so as to obtain

[0152] The composition of the produced solid ionic conductor compound was Li 5.75 PS 4.75 Cl 1.25 It was.

[0153] Comparative example 2: Li 5.75 P(S 4.72 O 0.03 )Cl 1.25 Manufacturing The desired composition is Li 5.75 P(S 4.72 O 0.03 )Cl 1.25 A solid ionic conductor compound was prepared in the same manner as in Example 1, except that CuS and LiSO were not added, but LiO was added, and the stoichiometric mixing ratio of the starting materials was changed so that

[0154] The composition of the produced solid ionic conductor compound was Li 5.75 P(S 4.72 O 0.03 )Cl 1.25 (Ratio of substituted anion (O): 0.006).

[0155] Reference example 1: (Li 5.69 Cu 0.06 )PS 4.75 Cl 1.25 Manufacturing The desired composition (Li 5.69 Cu 0.06 )PS 4.75 Cl1.25 A solid ionic conductor compound was prepared in the same manner as in Example 1, except that Li2SO4 was not added and the stoichiometric mixing ratio of the starting materials was changed so as to obtain

[0156] The composition of the produced solid ionic conductor compound is (Li 5.69 Cu 0.06 )PS 4.75 Cl 1.25 (Ratio of substituted cation (Cu): 0.01).

[0157] Reference example 2: (Li 5.72 Cu 0.03 )PS 4.75 Cl 1.25 Manufacturing The desired composition (Li 5.72 Cu 0.03 )PS 4.75 Cl 1.25 A solid ionic conductor compound was prepared in the same manner as in Example 1, except that Li2SO4 was not added and the stoichiometric mixing ratio of the starting materials was changed so as to obtain

[0158] The composition of the produced solid ionic conductor compound is (Li 5.72 Cu 0.03 )PS 4.75 Cl 1.25 (Ratio of substituted cation (Cu): 0.005).

[0159] Example 6: Production of all-solid-state secondary battery (Positive electrode layer manufacturing) As the positive electrode active material, LiNi 0.8 Co 0.15 Al 0.05 O2 (NCA) was prepared. The sulfide-based solid electrolyte powder produced in Example 1 was prepared as the solid electrolyte. Carbon nanofibers (CNF) were prepared as the conductive agent. These materials were mixed in a weight ratio of positive electrode active material: solid electrolyte: conductive agent = 60:35:5 to prepare a positive electrode mixture.

[0160] (Preparation of solid electrolyte powder) The sulfide-based solid ion conductor compound prepared in Example 1 was pulverized using an agate mortar and used as a solid electrolyte powder.

[0161] (Negative electrode layer manufacturing) A metallic lithium foil with a thickness of 30 μm was prepared as the negative electrode.

[0162] (Manufacturing of all-solid-state secondary batteries) The negative electrode layer, 150 mg of solid electrolyte powder, and 15 mg of positive electrode mixture were laminated in this order on the SUS lower electrode, and then the SUS upper electrode was placed on the positive electrode mixture to prepare a laminate. After that, the prepared laminate was subjected to a pressure of 4 ton / cm 2 The pressed laminate was then pressed for 2 minutes at a pressure of 1000 kJ / cm2 using a torque wrench. Next, a torque of 4 Nm was applied to the pressed laminate to prepare an all-solid-state secondary battery.

[0163] Examples 7 to 10 All-solid-state secondary batteries were fabricated in the same manner as in Example 6, except that the solid electrolyte powders prepared in Examples 2 to 5 were used instead of the solid electrolyte powder prepared in Example 1.

[0164] Comparative Example 3 All-solid-state secondary batteries were manufactured in the same manner as in Example 6, except that the solid electrolyte powder prepared in Comparative Example 1 was used instead of the solid electrolyte powder prepared in Example 1.

[0165] Evaluation example 1: X-ray diffraction experiment The solid ion conductor compounds produced in Examples 1 to 5 and Reference Examples 1 and 2 were pulverized using an agate mortar to prepare powders, and then the powder XRD spectra were measured. A part of the results is shown in FIGS. 1A to 1C. CuKα radiation was used for the XRD spectrum measurement. It was confirmed that the solid ion conductor compounds of Examples 1 to 5 and Reference Example 1 belong to the F-43m space group, have a structure belonging to the cubic crystal boundary crystal system, and are argyrodite-type sulfides having an argyrodite-type crystal structure. FIG. 1B is a partially enlarged view of FIG. 1A, and FIG. 1C is a partially enlarged view of FIG. 1B, and is a drawing comparing the peak positions of the solid ion conductor compounds of Example 2 and Reference Example 1.

[0166] In FIGS. 1A and 1B, for the solid ion conductor compound of Example 2, a peak corresponding to the LiCl phase was observed in the vicinity of the diffraction angle 2θ = 35°. Also, no peak due to impurities containing SO4 was observed.

[0167] Therefore, the peak caused by the LiCl phase is judged to be a peak shown by the re-precipitation of a part of Cl in the LiCl form due to the substitution of SO4 at the S(4c) site and / or the Cl(4a) site, excluding the P(4b) site and the S(16c) site of the tetrahedral PS4 group included in the argyrodite-type crystal structure, in the solid ion conductor compound of Example 2. Therefore, it was confirmed that SO4 was substituted at the S(4c) site and / or the Cl(4a) site in the solid ion conductor compound of Example 2. The Cl(4a) site is a site where S exists before Cl is substituted.

[0168] As can be seen from FIG. 1C, the solid ion conductor compound of Example 2 showed a first peak at a diffraction angle 2θ = 30.14° and a second peak at a diffraction angle 2θ = 31.52°.

[0169] 1C, the solid ion conductor compound of Reference Example 1 (having the same composition as the solid ion conductor compound of Example 2 except that SO4 was replaced with S) exhibited a third peak at a diffraction angle 2θ=30.18° and a fourth peak at a diffraction angle 2θ=31.56°. Therefore, it was confirmed that the first and second peaks of the solid ion conductor compound of Example 2 were downshifted by 0.04° to lower angles compared to the third and fourth peaks of the solid ion conductor compound of Reference Example 1.

[0170] Such a downshift was determined to be due to an increase in the distance between adjacent planes (e.g., d spacing) of the crystal lattice caused by the substitution of a portion of S with SO, which has a larger ionic radius than S, in the solid ionic conductor compound of Example 2.

[0171] Evaluation example 2: Ion conductivity measurement The solid ion conductor compounds produced in Examples 1 to 5 and Comparative Examples 1 and 2 were crushed in an agate mortar to prepare powders. Then, 200 mg of the powders were crushed in a mortar at a pressure of 4 ton / cm. 2 The specimen was pressed at a pressure of 0.05 for 2 minutes to prepare a pellet specimen with a thickness of approximately 100 μm and a diameter of approximately 13 mm. Indium (In) electrodes with a thickness of 50 μm and a diameter of 13 mm were placed on both sides of the specimen to prepare a symmetric cell. The preparation of the symmetric cell was carried out in a glove box with an Ar atmosphere.

[0172] For a specimen with indium electrodes arranged on both sides, an impedance analyzer (Material Mates 7260 impedance analyzer) was used to measure the impedance of the pellet by the two-probe method. The frequency range was from 0.1 Hz to 1 MHz, and the amplitude voltage was 10 mV. The measurement was carried out at 25 °C in an Ar atmosphere. The resistance value was obtained from the arc of the Nyquist plot related to the impedance measurement result, and the ionic conductivity was calculated considering the area and thickness of the specimen. The measurement results are shown in Table 1 below.

[0173]

Table 1

[0174] As can be seen from Table 1, the solid ion conductor compounds of Examples 1 to 5 showed a high ionic conductivity of 2.3 mS / cm or more at room temperature.

[0175] The solid ion conductor compounds of Examples 1 to 5 showed improved ionic conductivity compared to the solid ion conductor compound of Comparative Example 1.

[0176] The solid ion conductor compound of Example 5 had the corresponding composition, but showed improved ionic conductivity compared to the solid ion conductor compound of Comparative Example 2 in which O was substituted instead of SO4. In the solid ion conductor compound of Example 5, sulfate ions (SO4 2- ; ionic radius of 0.140 nm) having an increased ionic radius compared to oxygen ions (O 2- ; ionic radius of 147 nm) were substituted, and it was judged that improved ionic conductivity was provided due to distortion of the crystal structure, etc.

[0177] The ionic conductivity of the solid ionic conductor compound of Example 2 was lower than that of the solid ionic conductor compound of Comparative Example 2, and it was determined that such a lowered ionic conductivity was due to the fact that Cu was additionally substituted in addition to SO4, and the substitution contents were high. For example, Examples 1 and 3, which had low substitution contents of Cu and SO4, showed ionic conductivities equal to or higher than those of Comparative Example 2.

[0178] Evaluation example 3: Atmospheric stability evaluation The solid ionic conductor compounds prepared in Examples 1 and 2 and Comparative Example 1 were pulverized using an agate mortar to prepare powders. The prepared powders were then stored in a dry room in an air atmosphere with a dew point below -60°C for 10 days, and then removed and measured for change in ionic conductivity. The change in ionic conductivity was calculated using the ionic conductivity maintenance rate of Equation 1 below. The measurement results are shown in Table 2 below. The initial ionic conductivity is the ionic conductivity of the prepared powder before storage in the dry room. The ionic conductivity was measured using the same method and conditions as in Evaluation Example 2. [Formula 1] Ion conductivity retention rate [%] = [Ion conductivity of solid ionic conductor compound after 10 days / Initial ionic conductivity of solid ionic conductor compound] × 100

[0179] [Table 2]

[0180] As can be seen from Table 2, the solid ionic conductor compounds of Examples 1 and 2 showed improved ionic conductivity retention rates compared to the solid ionic conductor compound of Comparative Example 1.

[0181] The solid ionic conductor compounds of Examples 1 and 2 exhibited improved atmospheric or oxidative stability compared to the solid ionic conductor compound of Comparative Example 1.

[0182] Evaluation example 4: Charge / discharge test, interface stability evaluation The charge-discharge characteristics of all-solid-state secondary batteries manufactured in Examples 6 and 7 and Comparative Example 3 were evaluated by the following charge-discharge test. The charge-discharge test was performed by placing the all-solid-state secondary battery in a chamber at 45°C.

[0183] In the first cycle, until the battery voltage reached 4.25 V, it was charged at a constant current of 0.1 C and a constant voltage of 4.25 V until the current value reached 0.05 C. Next, until the battery voltage reached 2.5 V, discharge was performed at a constant current of 0.1 C.

[0184] The discharge capacity of the first cycle was taken as the standard capacity.

[0185] In the second cycle, until the battery voltage reached 4.25 V, it was charged at a constant current of 0.1 C and a constant voltage of 4.25 V for 50 hours. Next, until the battery voltage reached 2.5 V, discharge was performed at a constant current of 0.1 C.

[0186] The discharge capacity of the second cycle was taken as the retention capacity.

[0187] In the third cycle, until the battery voltage reached 4.25 V, it was charged at a constant current of 0.1 C and a constant voltage of 4.25 V until the current value reached 0.05 C. Next, until the battery voltage reached 2.5 V, discharge was performed at a constant current of 0.1 C.

[0188] The discharge capacity of the third cycle was taken as the recovery capacity.

[0189] For each cycle, a 10-minute rest period was placed after the charging stage and after the discharging stage.

[0190] The capacity recovery rate after high-temperature storage and the capacity retention rate after high-temperature storage of all-solid-state secondary batteries manufactured in Examples 6 to 7 and Comparative Example 3 are shown in Table 3 below.

[0191] The capacity retention rate after high-temperature storage and the capacity recovery rate after high-temperature storage are calculated from the following Formulas 2 and 3. [Formula 2] Maintenance capacity ratio (%) = [Maintenance capacity / Standard capacity] x 100 [Formula 3] Recovery capacity ratio (%) = [Recovery capacity / Standard capacity] x 100

[0192] [Table 3]

[0193] As can be seen from Table 3, the all-solid-state secondary batteries of Examples 6 and 7 exhibited improved retention capacity ratios and recovery capacity ratios after being left in a charged state at high temperature for a long period of time, compared to the all-solid-state secondary battery of Comparative Example 3.

[0194] The all-solid-state secondary batteries of Examples 6 and 7 exhibited improved stability (eg, oxidation resistance) to lithium metal compared to the all-solid-state secondary battery of Comparative Example 3. [Explanation of symbols]

[0195] 1, 1a All-solid-state secondary battery 10 positive electrode 11 Positive electrode current collector 12 Cathode active material layer 20 negative electrode 21 Negative electrode current collector 22 Negative electrode active material layer 23 Metal layer 30 Solid electrolyte layer 40 All-solid-state secondary battery

Claims

1. represented by the following chemical formula 1, having an al-dirodite type crystal structure, [Chemical formula 1] Li ｘ M1 ｖ PS ｙ M2 ｗ M3 ｚ In the chemical formula 1, M1 includes Na, K, Mg, Ag, Cu, Fe, Zn, Cr, Sn, V, or a combination thereof, M2 is SO ｎ and is M3 is one or more elements selected from Group 17 of the periodic table, a solid ion conductor compound where 4 ≦ x ≦ 8, 0 < v < 1, 3 ≦ y ≦ 7, 0 < w < 2, 0 ≦ z ≦ 2, and 1.5 ≦ n ≦ 5.

2. The solid ion conductor compound according to Claim 1, where 0 ≦ v / (x + v) < 0.2 and 0 < w / (y + w) < 0.

2.

3. the SO ｎ is S ４ O ６ 、 S ３ O ６ 、 S ２ O ３ 、 S ２ O ４ 、 S ２ O ５ 、 S ２ O ６ 、 S ２ O ７ 、 S ２ O ８ 、 SO ４ 、 SO ５ 、 or a combination thereof, the solid ion conductor compound according to claim 1 or 2.

4. The solid ion conductor compound according to any one of Claims 1 to 3, where 0 ≦ v / (x + v) < 0.08 and 0 < w / (y + w) < 0.

08.

5. The solid ion conductor compound according to any one of Claims 1 to 4, where the M3 includes F, Cl, Br, I, or a combination thereof.

6. The solid ion conductor compound represented by the chemical formula 1 is represented by the following chemical formula 2, [Chemical formula 2] Li ７－ｍ×ｖ－ｚ M1 ｖ PS ６－ｗ－ｚ M2 ｗ M3 ｚ In the chemical formula 2, M1 includes Na, K, Mg, Ag, Cu, Fe, Zn, Cr, Sn, V, or a combination thereof, and m is the oxidation number of M1, M2 is SO ｎ and M3 is one or more elements selected from Group 17 of the periodic table, a solid ion conductor compound where 0 < v < 1, 0 < w < 2, 0 ≦ z ≦ 2, 1.5 ≦ n ≦ 5, and 1 ≦ m ≦ 2.

7. The solid ion conductor compound represented by the chemical formula 1 is represented by the following chemical formula 3 or 4, [Chemical formula 3] (Li １－ｄ M1 ｄ ) ａ P(S １－ｅ M2 ｅ ) ｂ M3 ｃ [Chemical formula 4] (Li １－ｄ M1 ｄ ) ａ Li ｆｃ P(S １＋ｆｃ－ｅ M2 ｅ ) ｂ (M3 １－ｆ M2 ｆ ) ｃ In the chemical formulas 3 and 4, M1 is Na, K, Mg, Ag, Cu, Fe, Zn, Cr, Sn, V, or a combination thereof, M2 is SO ４ and M3 is one or more elements selected from Group 17 of the periodic table, 5 ≦ a ≦ 7, 4 ≦ b ≦ 6, 0 ≦ c ≦ 2, a solid ion conductor compound where 0 < d ≦ 0.08, 0 < e ≦ 0.08, 0 < f ≦ 0.08, and 0 < e + f ≦ 0.

08. 【Claim ⑧】 The solid ion conductor compound represented by the chemical formula 1 is represented by the following chemical formula 5 or 6, [Chemical formula 5] (Li １－ｄ M1 ｄ ) ａ P(S １－ｅ (SO ４ ) ｅ ) ｂ M3 ｃ [Chemical formula 6] (Li １－ｄ M1 ｄ ) ａ Li ｆｃ P(S １＋ｆｃ－ｅ (SO ４ ) ｅ ) ｂ (M3 １－ｆ (SO ４ ) ｆ ) ｃ In the chemical formulas 5 and 6, M1 is Na, K, Mg, Ag, Cu, or a combination thereof, M3 is one or more elements selected from Group 17 of the periodic table, 5 ≦ a ≦ 7, 4 ≦ b ≦ 6, 0 ≦ c ≦ 2, The solid ion conductor compound according to claim 1, wherein 0 < d < 0.08, 0 < e < 0.08, 0 < f < 0.08, and 0 < e + f < 0.

08.

9. The solid ion conductor compound represented by the chemical formula 1 is represented by any one of the following chemical formulas 5a to 6e: [Chemical formula 5a] (Li １－ｄ Na ｄ ) ａ P(S １－ｅ (SO ４ ) ｅ ) ｂ M3 ｃ [Chemical formula 5b] (Li １－ｄ K ｄ ) ａ P(S １－ｅ (SO ４ ) ｅ ) ｂ M3 ｃ [Chemical formula 5c] (Li １－ｄ Mg ｄ ) ａ P(S １－ｅ (SO ４ ) ｅ ) ｂ M3 ｃ [Chemical formula 5d] (Li １－ｄ Ag ｄ ) ａ P(S １－ｅ (SO ４ ) ｅ ) ｂ M3 ｃ [Chemical formula 5e] (Li １－ｄ Cu ｄ ) ａ P(S １－ｅ (SO ４ ) ｅ ) ｂ M3 ｃ [Chemical formula 6a] (Li １－ｄ Na ｄ ) ａ Li ｆｃ P(S １＋ｆｃ－ｅ (SO ４ ) ｅ ) ｂ (M3 １－ｆ (SO ４ ) ｆ ) ｃ [Chemical formula 6b] (Li １－ｄ K ｄ ) ａ Li ｆｃ P(S １＋ｆｃ－ｅ (SO ４ ) ｅ ) ｂ (M3 １－ｆ (SO ４ ) ｆ ) ｃ [Chemical formula 6c] (Li １－ｄ Mg ｄ ) ａ Li ｆｃ P(S １＋ｆｃ－ｅ (SO ４ ) ｅ )[[ID=IS]] ｂ (M3 １－ｆ (SO ４ ) ｆ ) ｃ [Chemical formula 6d] (Li １－ｄ Ag ｄ ) ａ Li ｆｃ P(S １＋ｆｃ－ｅ (SO ４ ) ｅ ) ｂ (M3 １－ｆ (SO ４ ) ｆ ) ｃ [Chemical formula 6e] (Li １－ｄ Cu ｄ ) ａ Li ｆｃ P(S １＋ｆｃ－ｅ (SO ４ ) ｅ ) ｂ (M3 １－ｆ (SO ４ ) ｆ ) ｃ In the chemical formulas 5a to 6e, M3 is an element selected from Group 17 of the periodic table; a, b, and c are independently selected from each other, where 5 ≤ a ≤ 7, 4 ≤ b ≤ 6, and 0 ≤ c ≤ 2; d, e, and f are independently selected from each other, where 0 < d ≤ 0.06, 0 < e ≤ 0.06, 0 < f ≤ 0.06, and 0 < e + f ≤ 0.

06. The solid ion conductor compound according to claim 1.

10. The solid ion conductor compound represented by the chemical formula 1 is represented by any of the following chemical formulas, (Li １－ｄ Cu ｄ ) ａ P(S １－ｅ (SO ４ ) ｅ ) ｂ F ｃ 、(Li １－ｄ Cu ｄ ) ａ P(S １－ｅ (SO ４ ) ｅ ) ｂ Cl ｃ 、(Li １－ｄ Cu ｄ ) ａ P(S １－ｅ (SO ４ ) ｅ ) ｂ Br ｃ 、(Li １－ｄ Cu ｄ ) ａ P(S １－ｅ (SO ４ ) ｅ ) ｂ I ｃ 、 (Li １－ｄ Cu ｄ ) ａ Li ｆｃ P(S １＋ｆｃ－ｅ (SO ４ ) ｅ ) ｂ (F １－ｆ (SO ４ ) ｆ ) ｃ 、(Li １－ｄ Cu ｄ ) ａ Li ｆｃ P(S １＋ｆｃ－ｅ (SO ４ ) ｅ ) ｂ (Cl １－ｆ (SO ４ ) ｆ ) ｃ 、(Li １－ｄ Cu ｄ ) ａ Li ｆｃ P(S １＋ｆｃ－ｅ (SO ４ ) ｅ ) ｂ (Br １－ｆ (SO ４ ) ｆ ) ｃ 、(Li １－ｄ Cu ｄ ) ａ Li ｆｃ P(S １＋ｆｃ－ｅ (SO ４ ) ｅ ) ｂ (I １－ｆ (SO ４ ) ｆ ) ｃ 、 (Li １－ｄ Na ｄ ) ａ P(S １－ｅ (SO ４ ) ｅ ) ｂ F ｃ 、(Li １－ｄ Na ｄ ) ａ P(S １－ｅ (SO ４ ) ｅ ) ｂ Cl ｃ 、(Li １－ｄ Na ｄ ) ａ P(S １－ｅ (SO ４ ) ｅ ) ｂ Br ｃ 、(Li １－ｄ Na ｄ ) ａ P(S １－ｅ (SO ４ ) ｅ ) ｂ I ｃ 、 (Li １－ｄ Na ｄ ) ａ Li ｆｃ P(S １＋ｆｃ－ｅ (SO ４ ) ｅ ) ｂ (F １－ｆ (SO ４ ) ｆ ) ｃ 、(Li １－ｄ Na ｄ ) ａ Li ｆｃ P(S １＋ｆｃ－ｅ (SO ４ ) ｅ ) ｂ (Cl １－ｆ (SO ４ ) ｆ ) ｃ 、(Li １－ｄ Na ｄ ) ａ Li ｆｃ P(S １＋ｆｃ－ｅ (SO ４ ) ｅ ) ｂ (Br １－ｆ (SO ４ ) ｆ ) ｃ 、(Li １－ｄ Na ｄ ) ａ Li ｆｃ P(S １＋ｆｃ－ｅ (SO ４ ) ｅ ) ｂ (I １－ｆ (SO ４ ) ｆ ) ｃ 、 (Li １－ｄ K ｄ ) ａ P(S １－ｅ (SO ４ ) ｅ ) ｂ F ｃ 、(Li １－ｄ K ｄ ) ａ P(S １－ｅ (SO ４ ) ｅ ) ｂ Cl ｃ 、(Li １－ｄ K ｄ [[ID=~36]]) ａ P(S １－ｅ (SO ４ ) ｅ ) ｂ Br ｃ 、(Li １－ｄ K ｄ ) ａ P(S １－ｅ (SO ４ ) ｅ ) ｂ I ｃ 、 (Li １－ｄ K ｄ ) ａ Li ｆｃ P(S １＋ｆｃ－ｅ (SO ４ ) ｅ ) ｂ (F １－ｆ (SO ４ ) ｆ ) ｃ 、(Li １－ｄ K ｄ ) ａ Li ｆｃ P(S １＋ｆｃ－ｅ (SO ４ ) ｅ ) ｂ (Cl １－ｆ (SO ４ ) ｆ ) ｃ 、(Li １－ｄ K ｄ ) ａ Li ｆｃ P(S １＋ｆｃ－ｅ (SO ４ ) ｅ ) ｂ (Br １－ｆ (SO ４ ) ｆ ) ｃ 、(Li １－ｄ K ｄ ) ａ Li ｆｃ P(S １＋ｆｃ－ｅ (SO ４ ) ｅ ) ｂ (I １－ｆ (SO ４ ) ｆ ) ｃ 、 (Li １－ｄ Mg ｄ ) ａ P(S １－ｅ (SO ４ ) ｅ ) ｂ F ｃ (Li １－ｄ Mg ｄ ) ａ P(S １－ｅ (SO ４ ) ｅ ) ｂ Cl ｃ (Li １－ｄ Mg ｄ ) ａ P(S １－ｅ (SO ４ ) ｅ ) ｂ Br ｃ (Li １－ｄ Mg ｄ ) ａ P(S １－ｅ (SO ４ ) ｅ ) ｂ I ｃ , (Li １－ｄ Mg ｄ ) ａ Li ｆｃ P(S １＋ｆｃ－ｅ (SO ４ ) ｅ ) ｂ (F １－ｆ (SO ４ ) ｆ ) ｃ 、(Li １－ｄ Mg ｄ ) ａ Li ｆｃ P(S １＋ｆｃ－ｅ (SO ４ ) ｅ ) ｂ (Cl １－ｆ (SO ４ ) ｆ ) ｃ 、(Li １－ｄ Mg ｄ ) ａ Li ｆｃ P(S １＋ｆｃ－ｅ (SO ４ ) ｅ ) ｂ (Br １－ｆ (SO ４ ) ｆ ) ｃ 、(Li １－ｄ Mg ｄ ) ａ Li ｆｃ P(S １＋ｆｃ－ｅ (SO ４ ) ｅ ) ｂ (I １－ｆ (SO ４ ) ｆ ) ｃ 、 (Li １－ｄ Ag ｄ ) ａ P(S １－ｅ (SO ４ ) ｅ ) ｂ F ｃ 、(Li １－ｄ Ag ｄ ) ａ P(S １－ｅ (SO ４ ) ｅ ) ｂ Cl ｃ 、(Li １－ｄ Ag ｄ ) ａ P(S １－ｅ (SO ４ ) ｅ ) ｂ Br ｃ 、(Li １－ｄ Ag ｄ ) ａ P(S １－ｅ (SO ４ ) ｅ ) ｂ I ｃ 、 (Li １－ｄ Ag ｄ ) ａ Li ｆｃ P(S １＋ｆｃ－ｅ (SO ４ ) ｅ ) ｂ (F １－ｆ (SO ４ ) ｆ ) ｃ 、(Li １－ｄ Ag ｄ ) ａ Li ｆｃ P(S １＋ｆｃ－ｅ (SO ４ ) ｅ ) ｂ (Cl １－ｆ (SO ４ ) ｆ ) ｃ 、(Li １－ｄ Ag ｄ ) ａ Li ｆｃ P(S １＋ｆｃ－ｅ (SO ４ ) ｅ ) ｂ (Br １－ｆ (SO ４ ) ｆ ) ｃ 、(Li １－ｄ Ag ｄ ) ａ Li ｆｃ P(S １＋ｆｃ－ｅ (SO ４ ) ｅ ) ｂ (I １－ｆ (SO ４ ) ｆ ) ｃ In the chemical formula, a, b, c, d, e, and f are independently selected from each other, where 5 ≤ a ≤ 7, 4 ≤ b ≤ 6, and 0 ≤ c ≤ 2; and 0 < d ≤ 0.06, 0 < e < 0.06, 0 < f < 0.06, and 0 < e + f < 0.

06. The solid ion conductor compound according to claim 1.

11. The solid ion conductor compound represented by the chemical formula 1 is represented by the following chemical formula ⑦, [Chemical formula 7] Li ７－ｐ×ｖ－ｕ－ｚ M4 ｖ M5 ｕ PS ６－ｗ－ｚ M2 ｗ M3 ｚ In the chemical formula 7, M4 is one or more metal elements selected from Groups 2 to 15 of the periodic table, and p is the oxidation number of M4; M5 is one or more metal elements other than Li selected from Group 1 of the periodic table and is a monovalent cation; M2 is SO ｎ and M3 is one or more elements selected from Group 17 of the periodic table; 0 < v < 1, 0 < u < 1, 0 < w < 2, 0 ≤ z ≤ 2, 1.5 ≤ n ≤ 5, and 1 ≤ p ≤ 2. The solid ion conductor compound according to claim 1.

12. A solid ion conductor compound represented by any of the following chemical formulas, Li ａ＋ｆｃ P(S １＋ｆｃ－ｅ (SO ４ ) ｅ ) ｂ (F １－ｆ (SO ４ ) ｆ ) ｃ 、Li ａ＋ｆｃ P(S １＋ｆｃ－ｅ (SO ４ ) ｅ ) ｂ (Cl １－ｆ (SO ４ ) ｆ ) ｃ 、Li ａ＋ｆｃ P(S １＋ｆｃ－ｅ (SO ４ ) ｅ ) ｂ (Br １－ｆ (SO ４ ) ｆ ) ｃ 、Li ａ＋ｆｃ P(S １＋ｆｃ－ｅ (SO ４ ) ｅ ) ｂ (I １－ｆ (SO ４ ) ｆ ) ｃ 、 Li ａ P(S １－ｅ (SO ４ ) ｅ ) ｂ F ｃ 、Li ａ P(S １－ｅ (SO ４ ) ｅ ) ｂ Br ｃ 、Li ａ P(S １－ｅ (SO ４ ) ｅ ) ｂ I ｃ In the chemical formula, 5 ≤ a ≤ 7, 4 ≤ b ≤ 6, and 0 < c ≤ 2; and 0 < e < 0.06, 0 < f < 0.06, and 0 < e + f < 0.06, The solid ion conductor compound having an alditol type crystal structure.

13. The solid ion conductor compound represented by the above Chemical Formula 1 has an ionic conductivity of 1.0 mS / cm or more at 25°C, and the solid ion conductor compound according to any one of Claims 1 to 12.

14. The solid ion conductor compound represented by the above Chemical Formula 1 has an ionic conductivity retention rate of 70% or more in the analysis after 10 days under the drying conditions of an air atmosphere having a dew point of less than -60°C, The ionic conductivity retention rate is represented by the following Mathematical Formula 1, 【Mathematical Formula 1】 Ionic conductivity retention rate = [Ionic conductivity of the solid ion conductor compound after 10 days / Ionic conductivity of the initial solid ion conductor compound] × 100% and the solid ion conductor compound according to any one of Claims 1 to 13.

15. The solid ion conductor compound represented by the above Chemical Formula 1 belongs to the cubic grain boundary crystal system, and the solid ion conductor compound according to any one of Claims 1 to 14.

16. The solid ion conductor compound represented by the above Chemical Formula 1 belongs to the F-43m space group, and the solid ion conductor compound according to any one of Claims 1 to 15.

17. The solid ion conductor compound represented by Chemical Formula 1 includes a first peak at a diffraction angle 2θ = 30.1° ± 0.5° and a second peak at a diffraction angle 2θ = 31.5° ± 0.5° in an XRD (X-ray diffraction) spectrum using CuKα radiation, A compound having the same composition as the solid ion conductor compound represented by Chemical Formula 1, except that M2 is changed to S, includes a third peak at a diffraction angle 2θ = 30.1° ± 0.5° and a fourth peak at a diffraction angle 2θ = 31.5° ± 0.5° in an XRD spectrum using CuKα radiation, When a part of S in the solid ion conductor compound is substituted with SO4 2-, the positions of the first peak and the second peak are each shifted down by 0.01° or more compared to the third peak and the fourth peak, and the solid ion conductor compound according to any one of Claims 1 to 16.

18. The solid ion conductor compound according to any one of Claims 1 to 17 further includes a peak corresponding to LiM3 reprecipitated by M2 at a diffraction angle 2θ = 35.0° ± 1.0° in an XRD spectrum using CuKα radiation.

19. A lithium transition metal oxide, a transition metal sulfide, a lithium transition metal sulfide, or a combination thereof, and a solid ion conductor compound according to any one of claims 1 to 18 on the surface of the lithium transition metal oxide, the transition metal sulfide or the lithium transition metal sulfide, comprising a protective cathode active material.

20. A solid electrolyte containing the solid ion conductor compound according to any one of claims 1 to 18.

21. A positive electrode layer including a positive electrode active material layer, A negative electrode layer including a negative electrode active material layer, An electrolyte layer disposed between the positive electrode layer and the negative electrode layer, and An electrochemical cell in which one or more of the positive electrode active material layer and the electrolyte layer contain the solid ion conductor compound according to any one of claims 1 to 18.

22. The electrochemical cell according to claim 21, wherein the electrochemical cell is an all-solid-state secondary battery.

23. The negative electrode active material layer includes a negative electrode active material and a binder, The electrochemical cell according to claim 21 or 22, wherein the negative electrode active material is a mixture of amorphous carbon and one or more selected from the group consisting of gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn) and zinc (Zn).

24. A negative electrode current collector, and A metal layer disposed between the negative electrode current collector and the negative electrode active material layer, the metal layer containing lithium or a lithium alloy, the electrochemical cell according to any one of claims 21 to 23.

25. A compound containing lithium, one or more compounds containing a metal element other than Li selected from Groups 1 to 15 of the periodic table, a compound containing phosphorus (P), and SO ｎ (1.5 ≦ n ≦ 5), contacting with a compound containing a Group 17 element of the periodic table to provide a mixture; A method for producing a solid ion conductor compound, comprising the step of heat-treating the mixture in an inert atmosphere to provide a solid ion conductor compound.

26. The method for producing a solid ion conductor compound according to claim 25, wherein the heat treatment includes the step of treating at a temperature of 400 ° C to 600 ° C for 1 to 36 hours.

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