Oxide, method for preparing the same, solid electrolyte comprising the oxide, and electrochemical device comprising the oxide

Abstract

The present invention relates to an oxide, a method for preparing the same, a solid electrolyte including the oxide, and an electrochemical device including the oxide. The oxide includes a compound represented by Formula 1, wherein, in Formula 1, 6 ≤ x ≤ 8, 0 ≤ y < 2, -0.2 ≤ δ ≤ 0.2, -0.2 ≤ ω ≤ 0.2, and 0 ≤ z ≤ 2; M1 is a monovalent cation, a divalent cation, a trivalent cation, or a combination thereof; M2 is a monovalent cation, a divalent cation, a trivalent cation, or a combination thereof; M3 is a monovalent cation, a divalent cation, a trivalent cation, a tetravalent cation, a pentavalent cation, a hexavalent cation, or a combination thereof; wherein at least one of M1, M2, or M3 includes at least four elements; and X is a monovalent anion, a divalent anion, a trivalent anion, or a combination thereof. Formula 1 (Li x M1 y )(M2) 3‑δ (M3) 2‑ω O 12‑z X z。

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2019-0094937, filed on August 5, 2019, in the Korean Intellectual Property Office, and all rights arising therefrom, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] The present disclosure relates to oxides, methods of preparing the oxides, solid electrolytes including the oxides, and electrochemical devices including the oxides. Background Art

[0004] Due to the high electrochemical capacity, high working potential, and excellent charge / discharge cycle characteristics of lithium secondary batteries, the demand for lithium secondary batteries has increased. Lithium secondary batteries are used in portable information terminals, portable electronic devices, small household power storage devices, motorcycles, electric vehicles and hybrid electric vehicles. As lithium secondary batteries are increasingly used in a variety of devices, the improved safety and improved performance of lithium secondary batteries are needed.

[0005] Commercially available lithium secondary batteries use liquid electrolytes that are easily ignited when exposed to water in the air, and therefore stability is a problem about these batteries. With the emergence of electric vehicles, stability issues have become prominent. Therefore, for the purpose of improving safety, all-solid-state secondary batteries using solid electrolytes formed by inorganic materials have been studied. Based on its stability, high energy density, high output, long life, simplified preparation process, increased size, compact size and reduced price, all-solid-state secondary batteries have been paid attention to as next-generation secondary batteries.

[0006] All-solid-state secondary batteries include a positive electrode, a solid electrolyte and a negative electrode. It is important that the solid electrolyte has high ionic conductivity and low electronic conductivity. Examples of solid electrolytes for all-solid-state secondary batteries include sulfide-based solid electrolytes or oxide-based solid electrolytes.

[0007] Although oxide-based solid electrolytes do not produce toxic materials during the preparation process and the stability of the materials is acceptable, the ionic conductivity of oxide-based solid electrolytes at room temperature is low compared to the ionic conductivity of sulfide-based solid electrolytes at room temperature. Therefore, there is still a need for improved oxide-based solid electrolytes having high ionic conductivity at room temperature. Summary of the invention

[0008] Provided are oxides having improved ionic conductivity and methods for preparing the oxides.

[0009] A solid electrolyte including the oxide is provided.

[0010] An electrochemical device including the oxide is provided.

[0011] Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description.

[0012] According to one aspect, the oxide includes a compound represented by Formula 1:

[0013] Formula 1

[0014] (Li x M1 y )(M2) 3-δ (M3) 2-ω O 12-z X z

[0015] Among them, in formula 1,

[0016] 6≤x≤8, 0≤y<2, −0.2≤δ≤0.2, −0.2≤ω≤0.2, and 0≤z≤2;

[0017] M1 is a monovalent cation, a divalent cation, a trivalent cation, or a combination thereof,

[0018] M2 is a monovalent cation, a divalent cation, a trivalent cation, or a combination thereof,

[0019] M3 is a monovalent cation, a divalent cation, a trivalent cation, a tetravalent cation, a pentavalent cation, a hexavalent cation, or a combination thereof, and

[0020] wherein at least one of M1, M2 or M3 comprises at least four elements; and

[0021] X is a monovalent anion, a divalent anion, a trivalent anion, or a combination thereof.

[0022] According to one aspect, a method for preparing an oxide comprises:

[0023] providing a precursor mixture comprising a lithium precursor, optionally an M1 precursor, an M2 precursor, an M3 precursor, and optionally an X precursor; and

[0024] The precursor mixture is heat-treated in an oxidizing gas to prepare a compound represented by Formula 1:

[0025] Formula 1

[0026] (Li x M1 y )(M2) 3-δ (M3) 2-ω O 12-z Xz

[0027] Among them, in formula 1,

[0028] 6≤x≤8, 0≤y<2, −0.2≤δ≤0.2, −0.2≤ω≤0.2, and 0≤z≤2;

[0029] M1 is a monovalent cation, a divalent cation, a trivalent cation, or a combination thereof,

[0030] M2 is a monovalent cation, a divalent cation, a trivalent cation, or a combination thereof,

[0031] M3 is a monovalent cation, a divalent cation, a trivalent cation, a tetravalent cation, a pentavalent cation, a hexavalent cation, or a combination thereof, and

[0032] wherein at least one of M1, M2 or M3 comprises at least four elements; and

[0033] X is a monovalent anion, a divalent anion, a trivalent anion, or a combination thereof.

[0034] According to one aspect, a solid electrolyte includes a binder and the oxide.

[0035] According to one aspect, an electrochemical device includes a positive electrode, a negative electrode, and a solid electrolyte, wherein the positive electrode, the negative electrode, the solid electrolyte, or a combination thereof includes the oxide.

[0036] The electrochemical device may be an electrochemical cell, wherein the solid electrolyte may be between a positive electrode and a negative electrode.

[0037] The solid electrolyte may be in the form of a protective layer, wherein the protective layer is on the positive electrode, the negative electrode, or a combination thereof.

[0038] According to one aspect, the oxide includes a compound represented by Formula 1:

[0039] Formula 1

[0040] (Li x M1 y )(M2) 3-δ (M3) 2-ω O 12-z X z

[0041] Among them, in formula 1,

[0042] 6≤x≤8, 0≤y<2, −0.2≤δ≤0.2, −0.2≤ω≤0.2, and 0≤z≤2;

[0043] M1 is hydrogen, iron, gallium, aluminum, boron, beryllium, or a combination thereof;

[0044] M2 is lanthanum, barium, or a combination thereof; and

[0045] M3 is zirconium, hafnium, tin, niobium, scandium, indium, or a combination thereof;

[0046] wherein at least one of M1, M2 or M3 comprises at least four elements; and

[0047] X is a halogen, a pseudohalogen, or a combination thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The above and other aspects, features and advantages of some embodiments of the present disclosure will become more apparent from the following description considered in conjunction with the accompanying drawings, in which:

[0049] Figure 1 is a schematic diagram of an embodiment of a crystal structure of an oxide;

[0050] Figure 2A is a graph of intensity (arbitrary unit (au)) versus diffraction angle (°, 2θ) and shows the results of X-ray diffraction analysis of the oxides prepared in Example 1, Example 3, Comparative Example 1, and Comparative Example 2 when analyzed by X-ray diffraction (XRD) using Cu Kα radiation;

[0051] Figure 2B show Figure 2A an enlarged view of a portion of;

[0052] Figure 3A is a graph of conductivity (log, Siemens / centimeter (S / cm)) versus temperature (1000 / K) showing the activation energy of the oxide prepared in Example 3;

[0053] Figure 3B is a graph of conductivity (log, Siemens / centimeter (S / cm)) versus temperature (1000 / K) showing the activation energy of the oxide prepared in Example 1;

[0054] Figure 3C is a graph of conductivity (log, Siemens / centimeter (S / cm)) versus temperature (1000 / K) showing the activation energy of the oxide prepared in Comparative Example 1;

[0055] Figure 3D is a graph of conductivity (log, Siemens / centimeter (S / cm)) versus temperature (1000 / K) showing the activation energy of the oxide prepared in Comparative Example 2; and

[0056] Figures 4 to 6 Each is a cross-sectional view of an embodiment of a schematic structure of an all-solid-state battery. DETAILED DESCRIPTION

[0057] Embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings, wherein the same reference numerals refer to the same elements throughout. In this regard, the present embodiment may have different forms and should not be construed as being limited to the description set forth herein. Therefore, the following only describes the embodiments to illustrate aspects by reference to the accompanying drawings. As used herein, the term "and / or" includes any and all combinations of one or more of the related enumerated items. Expressions such as "at least one (kind)" when before or after a list of elements modify the entire list of elements and do not modify the individual elements of the list.

[0058] It will be understood that when an element is referred to as being “on” another element, it can be directly on the other element or intervening elements may be present therebetween. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present.

[0059] It will be understood that although the terms "first", "second", "third", etc. may be used herein to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings herein, the "first element", "component", "region", "layer" or "part" discussed below may be referred to as a second element, component, region, layer or part.

[0060] The terms used herein are only for the purpose of describing specific embodiments and are not intended to be restrictive. As used herein, "one (kind) (indefinite article) (a, an)", "said (the)" and "at least one (kind)" do not represent the limitation of quantity, and are intended to cover both the singular and the plural, unless the context clearly states otherwise. For example, "(one) element" has the same meaning as "at least one element", unless the context clearly states otherwise. "At least one (kind)" will not be interpreted as limiting "one (kind)". "Or" means "and / or". As used herein, the term "and / or" includes any and all combinations of one or more of the related enumerated items. It will be further understood that the term "comprising" or "including" when used in this specification, indicates that there are stated features, regions, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, regions, wholes, steps, operations, elements, components, and / or their sets.

[0061] In addition, relative terms such as "lower" or "bottom" and "upper" or "top" may be used herein to describe the relationship of one element to another element as shown in the figure. It will be understood that, in addition to the orientation shown in the figure, relative terms are also intended to include different orientations of the device. For example, if the device in one of the figures is turned over, the element described as being on the "lower" side of the other element will be oriented on the "upper" side of the other element. Therefore, depending on the specific orientation of the figure, the exemplary term "lower" may include both "lower" and "upper" orientations. Similarly, if the device in one of the figures is turned over, the element described as "below" or "below" the other element will be oriented "above" the other element. Therefore, the exemplary terms "below..." or "below..." may include both "above..." and "below..." orientations.

[0062] As used herein, "about" or "approximately" is inclusive of the stated value and means within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system). For example, "about" can mean within one or more standard deviations, or within ±30%, 20%, 10%, or 5% relative to the stated value.

[0063] 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 the present disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless clearly so defined herein.

[0064] Exemplary embodiments are described herein with reference to cross-sectional views as schematic diagrams of idealized embodiments. Thus, deviations from the shapes of the figures as a result of, for example, manufacturing techniques and / or tolerances are to be expected. Therefore, the embodiments described herein should not be construed as being limited to the specific shapes of the regions as illustrated herein, but rather include deviations in shape caused by, for example, manufacturing. For example, a region illustrated or described as flat may typically have rough and / or nonlinear features. Moreover, the illustrated sharp corners may be rounded. Therefore, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the precise shapes of the regions and are not intended to limit the scope of the claims.

[0065] Hereinafter, according to embodiments, an oxide, a method of preparing the oxide, a solid electrolyte including the oxide, and an electrochemical device including the oxide will be described in further detail.

[0066] According to an embodiment, the oxide includes a compound represented by Formula 1:

[0067] Formula 1

[0068] (Li x M1 y )(M2) 3-δ (M3) 2-ω O 12-z X z

[0069] In formula 1,

[0070] 6≤x≤8, 0≤y<2, −0.2≤δ≤0.2, −0.2≤ω≤0.2, and 0≤z≤2;

[0071] M1 is a monovalent cation, a divalent cation, a trivalent cation, or a combination thereof,

[0072] M2 is a monovalent cation, a divalent cation, a trivalent cation, or a combination thereof,

[0073] M3 is a monovalent cation, a divalent cation, a trivalent cation, a tetravalent cation, a pentavalent cation, a hexavalent cation, or a combination thereof, and

[0074] wherein at least one of M1, M2 or M3 comprises at least four elements; and

[0075] X is a monovalent anion, a divalent anion, a trivalent anion, or a combination thereof.

[0076] For example, in the oxide, M1, M2, or a combination thereof may include at least one element, and M3 may include a combination of multiple elements, for example, at least four elements.

[0077] In the oxide according to the embodiment, M1, M2, or a combination thereof may include at least two elements, and M3 may include a combination of multiple elements, for example, a combination of at least four elements.

[0078] That at least one of M1, M2, or M3 includes at least four elements may, for example, refer to a combination including at least four elements.

[0079] The combination including at least four elements may be a first combination including at least four elements, wherein the at least four elements may be at the M1 position, the M2 position, or the M3 position in the structure of the oxide, and one to three different elements may be at the remaining positions in the structure of the oxide. For example, one element may be at the M1 position, two different elements may be at the M2 position, and four different elements may be at the M3 position.

[0080] The combination including at least four elements may be a second combination including at least four elements, wherein the at least four elements may be at both the M1 position and the M2 position, both the M2 position and the M3 position, or both the M1 position and the M3 position, and one to three different elements may be at the remaining positions.

[0081] The combination including at least four elements may be a third combination including at least four elements, wherein the at least four elements may be introduced into all of the M1 position, the M2 position, and the M3 position.

[0082] As used herein, the term "at least four elements" may refer to, for example, four, five, six, or seven elements.

[0083] For example, in the oxide, at least one of M1 or M2 may include at least two elements; M3 may include at least four elements or a multi-element combination of, for example, four or five elements; and z may be 0, or X may be F.

[0084] In Formula 1, M2 may be La, Ba, or a combination thereof; M3 may include zirconium (Zr), hafnium (Hf), tin (Sn), niobium (Nb), scandium (Sc), indium (In), or a combination thereof, and include at least four elements or, for example, a combination of four or five elements; and z may be 0, or X may be F.

[0085] For example, in Formula 1, the monovalent anion as X may be a halogen, a pseudohalogen, or a combination thereof; the divalent anion as X may be S 2- or Se 2- ; and the trivalent anion as X may be N 3- .

[0086] In Formula 1, 6.6≤x≤8, 6.7≤x≤7.5, or 6.8≤x≤7.1.

[0087] As used herein, the term "pseudohalogen" refers to a molecule similar to a halogen in a free state (free state) formed by at least two electronegative atoms and producing an anion similar to a halide ion. Examples of pseudohalogens may include cyanide, cyanate, thiocyanate, azide, or a combination thereof.

[0088] Examples of halogen may include iodine (I), chlorine (Cl), bromine (Br), fluorine (F), or a combination thereof.

[0089] An example of a trivalent anion is N 3- .

[0090] In order to increase the lithium ion conductivity of an oxide solid electrolyte having a garnet structure, a method of reducing the amount of lithium in the oxide solid electrolyte by introducing a small amount of a dopant into the oxide solid electrolyte has been proposed.

[0091] However, when this method is used, the amount of lithium of the oxide solid electrolyte may be reduced and thus the increase in ion conductivity may be limited, and when an oxide having a reduced amount of lithium is disposed on lithium metal, interface stability between the oxide and lithium metal may deteriorate.

[0092] Thus, an oxide having increased ionic conductivity by stabilizing the cubic phase of the oxide is provided. Without wishing to be bound by theory, it is understood that by increasing the configuration entropy of the cubic phase by increasing the number of species of elements at specific positions of the garnet structure or garnet-like crystal structure, a reduction in the amount of lithium is prevented. When at least four elements are introduced into at least one of the M1, M2 or M3 positions of the oxide of Formula 1, the amount of lithium in the oxide is not reduced; and thus an oxide having improved lithium stability, such as stability to reduction or reduction stability, is provided compared to those of the oxide without the additional elements.

[0093] The oxide may be electrically neutral. In order to provide the oxide with electrical neutrality, Li may be introduced into the oxide. + Here, the introduced vacancies can become capable of Li + The position of the jump, and thus the activation energy for Li migration can be reduced. Moreover, as described above, the oxide may include a cubic phase, and thus may have a low activation energy. When the activation energy is reduced, the ionic conductivity at low temperature can be further increased.

[0094] The oxide may have a garnet structure, and may have a cubic phase. The increase in configuration entropy of the oxide will be described in detail below.

[0095] The composition of the oxide 100 having a garnet structure can be expressed as A x X 3 Q 2 O 12 (6≤x≤10), which contains an A position 120, an X position 130, and a Q position 140, such as Figure 1 Here, the elements located at the A, X, and Q positions may have mutually different oxygen coordinations.

[0096] The garnet structure can be polymorphic and can have either a tetragonal or cubic phase, and the cubic phase can be more stable than the tetragonal phase at relatively high temperatures. 7 X 3 Q 2 O 12In the composition of , it is known that the cubic phase is stable at a relatively high temperature and the tetragonal phase is stable at room temperature, and therefore the oxide having a garnet structure is generally obtained as having a tetragonal phase. Therefore, when the oxide having a garnet structure desirably has a cubic phase, the amount of lithium is controlled to be less than 7 by doping to form a cubic phase in the oxide.

[0097] In the oxide according to the embodiment, when the number of different elements located at a specific crystallographic position of A, X, or Q increases, the phase stability may increase as the Gibbs free energy (ΔG) decreases based on the increase in configuration entropy (ΔS) as shown in Equation 1. This allows room temperature stabilization of the oxide by lowering the phase stabilization temperature range of the cubic phase.

[0098] Equation 1

[0099] ΔG=ΔH-TΔS

[0100] S=S 热力学 +S 位形

[0101] ΔS↑→ΔG↓

[0102] Unlike a conventional oxide having a garnet structure, the oxide according to the embodiment may reduce the phase stable temperature of the cubic phase without reducing the amount of lithium by doping a dopant in the oxide or performing a high-temperature heat treatment process, and thus may contain the cubic phase.

[0103] Figure 1 is a schematic diagram of a crystal structure of an oxide according to an embodiment.

[0104] refer to Figure 1 , the oxide 100 according to the embodiment has a garnet crystal structure including Li (M1 position) 120 , La (M2 position) 130 , and polyatoms (M3 position) 140 .

[0105] Unlike the prior art oxide having a garnet crystal structure including doped elements, the oxide according to the embodiment does not have a Li vacancy, and thus the amount of lithium in the oxide is maintained. Moreover, the number of elements in a specific crystallographic position of the garnet structure in the oxide increases, which causes an increase in configuration entropy, and thus the cubic phase can be stabilized and ion conductivity can be improved. Here, the elements occupying a specific crystallographic position, such as an M3 position, may be at least four elements, or four or five elements.

[0106] Moreover, X may be introduced into the oxygen (O) position of the oxide. Halogens such as chlorine or fluorine, or pseudohalogens may be introduced as X. When an oxide introduced with a halogen or pseudohalogen is used in the preparation of a solid electrolyte, a passivation layer including fluorine may be formed between a lithium metal electrode and a solid electrolyte containing an oxide according to an embodiment, which may improve the lithium stability of the solid electrolyte, and LiF or LiCl may be present in the grain boundary region of the solid electrolyte, which may increase the Li ion conductivity at the grain boundary.

[0107] The oxides can be used as lithium conductors.

[0108] In Formula 1, examples of monovalent cations may include Na, K, Rb, Cs, H, or Fr, and examples of divalent cations may include Mg, Ca, Ba, or Sr. Examples of trivalent cations may include In, Sc, Cr, Au, B, Al, or Ga, and examples of tetravalent cations may include Sn, Ti, Mn, Ir, Ru, Pd, Mo, Hf, Ge, V, or Si.

[0109] Examples of pentavalent cations may include Nb, Ta, Sb, V, or P.

[0110] M3 may include a tetravalent cation. In one aspect, M3 includes a tetravalent cation. In one aspect, M3 may be four tetravalent cations (combination 1); a combination of two tetravalent cations, a trivalent cation, and a pentavalent cation (combination 2); a combination of two tetravalent cations, a divalent cation, and a hexavalent cation (combination 3); a combination of three tetravalent cations, a trivalent cation, and a pentavalent cation (combination 4); a combination of three tetravalent cations, a divalent cation, and a hexavalent cation (combination 5); a combination of a tetravalent cation, two trivalent cations, and two pentavalent cations (combination 6); a combination of four tetravalent cations, a trivalent cation, and a pentavalent cation (combination 7); a combination of four tetravalent cations, a divalent cation, and a hexavalent cation (combination 8); a combination of two tetravalent cations, two trivalent cations, and two pentavalent cations (combination 9); or a combination of two tetravalent cations, two divalent cations, and two hexavalent cations (combination 10).

[0111] Examples of combination 1 may include Zr / Hf / Sn / Ru, Zr / Hf / Sn / Mo, Zr / Hf / Sn / Ir, Zr / Hf / Sn / Pd, Zr / Hf / Ru / Ir, Zr / Hf / Ru / Mo, Zr / Hf / Ru / Pd, Zr / Hf / Ir / Mo, Zr / Hf / Ir / Pd, Zr / Hf / Mo / Pd, or combinations thereof.

[0112] Examples of combination 2 may include Zr / Hf / In / Nb, Zr / Hf / In / Ta, Zr / Hf / In / Sb, Zr / Hf / Sc / Nb, Zr / Hf / Sc / Ta, Zr / Hf / Sc / Sb, Zr / Hf / Cr / Nb, Zr / Hf / Cr / Ta, Zr / Hf / Cr / Sb, Sn / Hf / In / Nb, Sn / Hf / In / Ta, Sn / Hf / In / Sb, Sn / Hf / Sc / Nb, Sn / Hf / Sc / Ta, Sn / Hf / Sc / Sb, Sn / Hf / Cr / Nb, Sn / Hf / Cr / Ta, Sn / Hf / Cr / Sb, Zr / Sn / In / Nb, Zr / Sn / In / Ta, Zr / Sn / In / Sb, Zr / Sn / Sc / Nb, Zr / Sn / Sc / Ta, Zr / Sn / Sc / Sb, Zr / Sn / Cr / Nb, Zr / Sn / Cr / Ta, Zr / Sn / Cr / Sb, or combinations thereof.

[0113] Examples of combination 3 may include Zr / Hf / Ni / Ru, Zr / Hf / Ni / Mo, Zr / Hf / Cu / Ru, Zr / Hf / Cu / Mo, Zr / Hf / Mg / Ru, Zr / Hf / Mg / Mo, Sn / Hf / Ni / Ru, Sn / Hf / Ni / Mo, Sn / Hf / Cu / Ru, Sn / Hf / Cu / Mo, Sn / Hf / Mg / Ru, Sn / Hf / Mg / Mo, Zr / Sn / Ni / Ru, Zr / Sn / Ni / Mo, Zr / Sn / Cu / Ru, Zr / Sn / Cu / Mo, Zr / Sn / Mg / Ru, Zr / Sn / Mg / Mo, or combinations thereof.

[0114] Combination 4 examples possible inclusive Zr / Hf / Sn / In / Nb, Zr / Hf / Sn / In / Ta, Zr / Hf / Sn / In / Sb, Zr / Hf / Sn / Sc / Nb, Zr / Hf / Sn / Sc / Ta, Zr / Hf / Sn / Sc / Sb, Zr / Hf / Sn / Cr / Nb, Zr / Hf / Sn / Cr / Ta, Zr / Hf / Sn / Cr / Sb, Zr / Hf / Ru / In / Nb, Zr / Hf / Ru / In / Ta, Zr / Hf / Ru / In / Sb, Zr / Hf / Ru / Sc / Nb, Zr / Hf / Ru / Sc / Ta, Zr / Hf / Ru / Sc / Sb, Zr / Hf / Ru / Cr / Nb, Zr / Hf / Ru / Cr / Ta, Zr / Hf / Ru / Cr / Sb, Zr / Mo / Sn / In / Nb, Zr / Mo / Sn / In / Ta, Zr / Mo / Sn / In / Sb, Zr / Mo / Sn / Sc / Nb, Zr / Mo / Sn / Sc / Ta, Zr / Mo / Sn / Sc / Sb, Zr / Mo / Sn / Cr / Nb, Zr / Mo / Sn / Cr / Ta, Zr / Mo / Sn / Cr / Sb, or combinations thereof.

[0115] Combination 5 practical examples Inclusive Zr / Hf / Sn / Ni / Ru, Zr / Hf / Sn / Ni / Mo, Zr / Hf / Sn / Cu / Ru, Zr / Hf / Sn / Cu / Mo, Zr / Hf / Sn / Mg / Ru, Zr / Hf / Sn / Mg / M o, Zr / Hf / Pd / Ni / Ru, Zr / Hf / Pd / Ni / Mo, Zr / Hf / Pd / Cu / Ru, Zr / Hf / Pd / Cu / Mo, Zr / Hf / Pd / Mg / Ru, Zr / Hf / Pd / Mg / Mo, or combinations thereof.

[0116] Examples of the combination 6 may include Zr / In / Sc / Nb / Ta, Zr / In / Sc / Nb / Sb, Zr / In / Sc / Ta / Sb, Zr / In / Cr / Nb / Ta, Zr / In / Cr / Nb / Sb, Zr / In / Cr / Ta / Sb, Zr / Cr / Sc / Nb / Ta, Zr / Cr / Sc / Nb / Sb, Zr / Cr / Sc / Ta / Sb, Hf / In / Sc / Nb / Ta, Hf / In / Sc / Nb / Sb, Hf / In / Sc / Ta / Sb, Hf / In / Cr / Nb / Ta, Hf / In / Cr / Nb / Sb, Hf / In / Cr / Ta / Sb, Hf / Cr / Sc / Nb / Ta, Hf / Cr / Sc / Nb / Sb, Hf / Cr / Sc / Ta / Sb, Sn / In / Sc / Nb / Ta, Sn / In / Sc / Nb / Sb, Sn / In / Sc / Ta / Sb, Sn / In / Cr / Nb / Ta, Sn / In / Cr / Nb / Sb, Sn / In / Cr / Ta / Sb, Sn / Cr / Sc / Nb / Ta, Sn / Cr / Sc / Nb / Sb, Sn / Cr / Sc / Ta / Sb, or a combination thereof.

[0117] Examples of the combination 7 may include Zr / Hf / Sn / Ru / In / Nb, Zr / Hf / Sn / Ru / In / Ta, Zr / Hf / Sn / Ru / In / Sb, Zr / Hf / Sn / Ru / Sc / Nb, Zr / Hf / Sn / Ru / Sc / Ta, Zr / Hf / Sn / Ru / Sc / Sb, Zr / Hf / Sn / Ru / Cr / Nb, Zr / Hf / Sn / Ru / Cr / Ta, Zr / Hf / Sn / Ru / Cr / Sb, Zr / Hf / Sn / Mo / In / Nb, Zr / Hf / Sn / Mo / In / Ta, Zr / Hf / Sn / Mo / In / Sb, Zr / Hf / Sn / Mo / Sc / Nb, Zr / Hf / Sn / Mo / Sc / Ta, Zr / Hf / Sn / Mo / Sc / Sb, Zr / Hf / Sn / Mo / Cr / Nb, Zr / Hf / Sn / Mo / Cr / Ta, Zr / Hf / Sn / Mo / Cr / Sb, or a combination thereof.

[0118] Examples of combination 8 may include Zr / Hf / Sn / Mn / Ni / Ru, Zr / Hf / Sn / Mn / Ni / Mo, Zr / Hf / Sn / Mn / Cu / Ru, Zr / Hf / Sn / Mn / Cu / Mo, Zr / Hf / Sn / Mn / Mg / Ru, Zr / Hf / Sn / Mn / Mg / Mo, Zr / Hf / Sn / Pd / Ni / Ru, Zr / Hf / Sn / Pd / Ni / Mo, Zr / Hf / Sn / Pd / Cu / Ru, Zr / Hf / Sn / Pd / Cu / Mo, Zr / Hf / Sn / Pd / Mg / Ru, Zr / Hf / Sn / Pd / Mg / Mo, or combinations thereof.

[0119] Examples of combination 9 may include Zr / Hf / In / Sc / Nb / Ta, Zr / Hf / In / Sc / Nb / Sb, Zr / Hf / In / Sc / Ta / Sb, Zr / Hf / In / Cr / Nb / Ta, Zr / Hf / In / Cr / Nb / Sb, Zr / Hf / In / Cr / Ta / Sb, Zr / Hf / In / Cr / Ta / Sb, Zr / Hf / Cr / Sc / Nb / Ta, Zr / Hf / Cr / Sc / Nb / Sb, Zr / Hf / Cr / Sc / Ta / Sb, or combinations thereof.

[0120] Examples of combination 10 may include Zr / Hf / Cu / Ni / Ru / Mo, Zr / Sn / Cu / Ni / Ru / Mo, Zr / Mn / Cu / Ni / Ru / Mo, Zr / Pd / Cu / Ni / Ru / Mo, Hf / Sn / Cu / Ni / Ru / Mo, Hf / Mn / Cu / Ni / Ru / Mo, Hf / Pd / Cu / Ni / Ru / Mo, Sn / Mn / Cu / Ni / Ru / Mo, Sn / Pd / Cu / Ni / Ru / Mo, or combinations thereof.

[0121] In the combinations, the slash symbol, ie, " / ", means that the elements shown are present in any stoichiometric amount.

[0122] The total number of elements in combinations 1 to 10 may be 2-ω (where -0.2≤ω≤0.2). For example, the mixing ratio of the elements constituting the combination may be changed so that the total number of elements in combinations 1 to 10 is 2. For example, when the combination has four different elements, examples of the mixing ratio of the four elements may include 5:5:5:5, 4:6:4:6, 6:4:6:4, 4:4:6:6, 6:6:4:4, 3:3:7:7, 7:7:3:3, 8:2:8:2, 7:3:7:3, 8:8:2:2, or 2:2:8:8.

[0123] When the composition has five different elements, examples of the mixing ratios of the five elements may include 4:4:4:4:4, 3:5:3:5:4, 5:3:5:3:4, 3:5:4:3:5, or 5:3:4:5:3.

[0124] The compound represented by Formula 1 may be an oxide represented by Formula 2:

[0125] Formula 2

[0126] (Li x M1 y )(La a1 M4 a2 ) 3-δ (M5 b1 M6 b2 M7 b3 M8 b4 M9 b5 ) 2-ω O 12-z X z

[0127] In Formula 2,

[0128] M1 may be hydrogen (H), iron (Fe), gallium (Ga), aluminum (Al), boron (B), beryllium (Be), or a combination thereof,

[0129] M4 may be barium (Ba), calcium (Ca), strontium (Sr), yttrium (Y), bismuth (Bi), praseodymium (Pr), neodymium (Nd), actinium (Ac), samarium (Sm), gadolinium (Gd), or a combination thereof, and

[0130] M5 to M9 may each independently be zirconium (Zr), hafnium (Hf), tin (Sn), niobium (Nb), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), molybdenum (Mo), tungsten (W), tantalum (Ta), magnesium (Mg), technetium (Tc), ruthenium (Ru), palladium (Pd), iridium (Ir), scandium (Sc), cadmium (Cd), indium (In), antimony (Sb), tellurium (Te), thallium (Tl), platinum (Pt), silicon (Si), aluminum (Al), or a combination thereof;

[0131] 6 ≤ x ≤ 8, 0 ≤ y < 2, -0.2 ≤ δ ≤ 0.2, -0.2 ≤ ω ≤ 0.2, 0 ≤ z ≤ 2,

[0132] a1 + a2 = 1, where 0 < a1 ≤ 1, 0 ≤ a2 < 1,

[0133] b1 + b2 + b3 + b4 + b5 = 1, where 0 < b1 < 1, 0 < b2 < 1, 0 < b3 < 1, 0 < b4 < 1, and 0 ≤ b5 < 1; and

[0134] X may be a monovalent anion, a divalent anion, a trivalent anion, or a combination thereof, and M5 to M9 are different from each other.

[0135] In Formula 1, M5 may be zirconium (Zr), hafnium (Hf), or a combination thereof. Also, for example, b1 to b5 may each independently be in the range of about 0.1 to about 0.9, for example, about 0.2 to about 0.8, about 0.3 to about 0.7, or about 0.4 to about 0.6.

[0136] Regarding the oxide according to the embodiment, the compound represented by Formula 1 may be a compound represented by Formula 3:

[0137] Formula 3

[0138] Li x (La a1 M10 a2 ) 3-δ (M11 b1 M12 b2 M13 b3 M14 b4 M15 b5 ) 2-ω O 12-z X z

[0139] In formula 3,

[0140] M10 may be barium (Ba), calcium (Ca), strontium (Sr), yttrium (Y), bismuth (Bi), praseodymium (Pr), neodymium (Nd), actinium (Ac), samarium (Sm), gadolinium (Gd), or a combination thereof.

[0141] M11 may be zirconium (Zr), hafnium (Hf), or a combination thereof, and

[0142] M12 to M15 may each independently be zirconium (Zr), hafnium (Hf), tin (Sn), niobium (Nb), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), molybdenum (Mo), tungsten (W), tantalum (Ta), magnesium (Mg), technetium (Tc), ruthenium (Ru), palladium (Pd), iridium (Ir), scandium (Sc), cadmium (Cd), indium (In), antimony (Sb), tellurium (Te), thallium (Tl), platinum (Pt), silicon (Si), aluminum (Al), or a combination thereof;

[0143] 6≤x≤8, −0.2≤δ≤0.2, −0.2≤ω≤0.2, and 0≤z≤2,

[0144] a1+a2=1, where 0 <a1≤1,0≤a2<1,

[0145] b1 + b2 + b3 + b4 + b5 = 1, where 0 < b1 < 1, 0 < b2 < 1, 0 < b3 < 1, 0 < b4 < 1, and 0 < b5 < 1; and

[0146] X can be a monoanion, dianion, trianion, or a combination thereof, and M12 to M15 are different from each other.

[0147] In Formula 3, M10 can be barium (Ba), M11 can be zirconium (Zr), M12 can be hafnium (Hf), and M13 to M15 can each independently be tin (Sn), niobium (Nb), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), molybdenum (Mo), tungsten (W), tantalum (Ta), magnesium (Mg), technetium (Tc), ruthenium (Ru), palladium (Pd), iridium (Ir), scandium (Sc), cadmium (Cd), indium (In), antimony (Sb), tellurium (Te), thallium (Tl), platinum (Pt), silicon (Si), or a combination thereof; and z can be 0, or if z is not 0, X can be F or Cl.

[0148] In Formula 3, for example, M13 to M15 can each independently be Sn, Nb, Sc, In, or a combination thereof; and z can be 0, or if z is not 0, X can be F or Cl.

[0149] In Formula 3, for example, b1 to b5 can each independently be in the range of about 0.1 to about 0.9 or for example about 0.2 to about 0.8, about 0.3 to about 0.7, or about 0.4 to about 0.6.

[0150] When the anion X substitutes some positions of oxygen, as a result of the inductive effect, the Li ion conductivity can increase. Moreover, when a passivation layer including F is formed, the lithium stability can be improved; and due to the presence of LiF or LiCl at the grain boundary region, the Li ion conductivity at the grain boundary can increase.

[0151] For example, the oxide can be Li x La 3 Zr b1 Hf b2 Sc b3 Nb b4 Sn b5 O 12 (where 6 ≤ x ≤ 8, b1 + b2 + b3 + b4 + b5 = 2, 0 < b1 < 1, 0 < b2 < 1, 0 < b3 < 1, 0 < b4 < 1, and 0 < b5 < 1), Li x La 3 Zr b1 Hf b2 In b3 Nb b4 O 12(where 6 ≤ x ≤ 8, b1 + b2 + b3 + b4 = 2, 0 < b1 < 1, 0 < b2 < 1, 0 < b3 < 1, and 0 < b4 < 1), Li x La 3 Zr b1 Hf b2 Sc b3 Nb b4 O 12 (where 6 ≤ x ≤ 8, b1 + b2 + b3 + b4 = 2, 0 < b1 < 1, 0 < b2 < 1, 0 < b3 < 1, and 0 < b4 < 1), Li x La 3 Zr b1 Hf b2 Sn b3 Ru b4 O 12 (where 6 ≤ x ≤ 8, b1 + b2 + b3 + b4 = 2, 0 < b1 < 1, 0 < b2 < 1, 0 < b3 < 1, and 0 < b4 < 1), Li x La a1 Ba a2 Zr b1 Hf b2 In b3 Nb b 4 Sn b5 O 12 (where 6 ≤ x ≤ 8, a1 + a2 = 3, b1 + b2 + b3 + b4 + b5 = 2, 0 < a1 < 3, 0 < a2 < 3, 0 < b1 < 1, 0 < b2 < 1, 0 < b3 < 1, 0 < b4 < 1, and 0 < b5 < 1), Li x La a1 Ba a2 Zr b1 Hf b2 Sc b3 Nb b4 Sn b5 O 12 (where 6 ≤ x ≤ 8, a1 + a2 = 3, b1 + b2 + b3 + b4 + b5 = 2, 0 < a1 < 3, 0 < a2 < 3, 0 < b1 < 1, 0 < b2 < 1, 0 < b3 < 1, 0 < b4 < 1, and 0 < b5 < 1), Li x La 3 Zr b1 Hf b2 Sn b3 Sc b4 Nb b5 O 12-z F z(where 6 ≤ x ≤ 8, b1 + b2 + b3 + b4 + b5 = 2, 0 < b1 < 1, 0 < b2 < 1, 0 < b3 < 1, 0 < b4 < 1, 0 < b5 < 1, and 0 ≤ z ≤ 2), Li x La 3 Zr b1 Hf b2 Sn b3 Sc b4 Nb b5 O 12-z Cl z (where 6 ≤ x ≤ 8, b1 + b2 + b3 + b4 + b5 = 2, 0 ≤ z ≤ 2, 0 < b1 < 1, 0 < b2 < 1, 0 < b3 < 1, 0 < b4 < 1, and 0 < b5 < 1), or a combination thereof.

[0152] For example, the oxide according to an embodiment may be Li 7 La 3 Zr 0.4 Hf 0.4 Sc 0.4 Nb 0.4 Sn 0.4 O 12 , Li 7 La 3 Zr 0.3 Hf 0.5 Sc 0.3 Nb 0.5 Sn 0.4 O 12 , Li 7 La 3 Zr 0.5 Hf 0.3 Sc 0.5 Nb 0.3 Sn 0.4 O 12 , Li 7 La 3 Zr 0.3 Hf 0.5 Sc 0.4 Nb 0.3 Sn 0.5 O 12 , Li 7 La 3 Zr 0.5 Hf 0.3 Sc 0.4 Nb 0.5 Sn 0.3 O 12 , Li 7 La 3 Zr 0.5 Hf 0.5 In 0.5 Nb0.5 O 12 Li 7 Day 3 Zr 0.4 Hf 0.6 In 0.4 No 0.6 O 12 Li 7 Day 3 Zr 0.6 Hf 0.4 In 0.6 No 0.4 O 12 Li 7 Day 3 Zr 0.4 Hf 0.4 In 0.6 No 0.6 O 12 Li 7 Day 3 Zr 0.6 Hf 0.6 In 0.4 No 0.4 O 12 Li 7 Day 3 Zr 0.5 Hf 0.5 Sc 0.5 No 0.5 O 12 Li 7 Day 3 Zr 0.4 Hf 0.6 Sc 0.4 No 0.6 O 12 Li 7 Day 3 Zr 0.6 Hf 0.4 Sc 0.6 No 0.4 O 12 Li 7 Day 3 Zr 0.4 Hf 0.4 Sc 0.6 No 0.6 O 12 Li 7 Day 3 Zr 0.6 Hf 0.6 Sc 0.4 No 0.4 O 12 Li 7 Day 3Zr 0.5 Hf 0.5 Mr 0.5 Ru 0.5 O 12 Li 7 Day 3 Zr 0.4 Hf 0.6 Mr 0.4 Ru 0.6 O 12 Li 7 Day 3 Zr 0.6 Hf 0.4 Mr 0.6 Ru 0.4 O 12 Li 7 Day 3 Zr 0.4 Hf 0.4 Mr 0.6 Ru 0.6 O 12 Li 7 Day 3 Zr 0.6 Hf 0.6 Mr 0.4 Ru 0.4 O 12 Li 7.1 Day 2.9 Ba 0.1 Zr 0.4 Hf 0.4 In 0.4 No 0. 4 Mr 0.4 O 12 Li 7.1 Day 2.9 Ba 0.1 Zr 0.3 Hf 0.5 In 0.3 No 0.5 Mr 0.4 O 12 Li 7.1 Day 2.9 Ba 0.1 Zr 0.5 Hf 0.3 In 0.5 No 0.3 Mr 0. 4 O 12 Li 7.1 Day 2.9 Ba 0.1 Zr 0.3 Hf 0.5In 0.4 No 0.3 Mr 0.5 O 12 Li 7.1 Day 2.9 Ba 0.1 Zr 0.5 Hf 0.3 In 0.4 No 0.5 Mr 0.3 O 12 Li 7.1 Day 2.9 Ba 0.1 Zr 0.4 Hf 0.4 Sc 0.4 No 0.4 Mr 0.4 O 12 Li 7.1 Day 2.9 Ba 0.1 Zr 0.3 Hf 0.5 Sc 0.3 No 0.5 Mr 0.4 O 12 Li 7.1 Day 2.9 Ba 0.1 Zr 0.5 Hf 0.3 Sc 0.5 No 0.3 Mr 0.4 O 12 Li 7.1 Day 2.9 Ba 0.1 Zr 0.3 Hf 0.5 Sc 0.4 No 0.3 Mr 0.5 O 12 Li 7.1 Day 2.9 Ba 0.1 Zr 0.5 Hf 0.3 Sc 0.4 No 0.5 Mr 0.3 O 12 Li 6.8 Day 3 Zr 0.4 Hf 0.4 Mr 0.4 Sc 0.4 No 0.4 O 11.8 F 0.2,He 6.8 The 3 Zr 0.3 Hf 0.5 Sn 0.3 Sc 0.5 Nb 0.4 Oh 11.8 F 0.2 ,He 6.8 The 3 Zr 0.5 Hf 0.3 Sn 0.5 Sc 0.3 Nb 0.4 Oh 11.8 F 0.2 ,He 6.8 The 3 Zr 0.3 Hf 0.5 Sn 0.4 Sc 0. 3 Nb 0.5 Oh 11.8 F 0.2 ,He 6.8 The 3 Zr 0.5 Hf 0.3 Sn 0.4 Sc 0.5 Nb 0.3 Oh 11.8 F 0.2 ,He 7 The 3 Zr 0.4 Hf 0.4 To 0.4 Nb 0.4 Sn 0.4 Oh 12 ,He 7.0 The 2.9 Y 0.1 Zr 0.4 Hf 0.4 Sc 0.4 Nb 0.4 Sn 0.4 Oh 12 ,He 7 The 3 Zr 0.5 Hf 0.5 To 0.5 Nb 0.5 Oh 12 ,He 6.8 The 3 Zr 0.4 Hf 0.4 Sn 0.4 Sc 0.4 Nb0.4 O 11.8 Cl 0.2 , or a combination thereof.

[0153] The amount of the element located in a specific position of the garnet structure in the oxide may be confirmed by X-ray diffraction (XRD) analysis, inductively coupled plasma (ICP) analysis, and / or neutron diffraction analysis.

[0154] In some embodiments, a singlet peak determined by X-ray diffraction (XRD) analysis of the oxide appears at a diffraction angle 2θ in the range of about 16° to about 20°, or, for example, about 16° to about 17.5° and / or about 19° to about 20°. From the presence of the singlet peak, it can be known that the oxide has a garnet or garnet-like crystal structure including a cubic phase.

[0155] In an embodiment, the ionic conductivity of the lithium conductor including the oxide of Formula 1 at room temperature (25° C.) may be at least about 1.0×10 -4 S / cm or, for example, at least about 2.0×10 -4 S / cm, at least about 2.73×10 -4 S / cm, or at least about 3.78×10 -4 S / cm, or about 3.78×10 -4 S / cm is about 1×10 -1 S / cm. For example, the ionic conductivity of the lithium conductor may be about 1×10 -4 S / cm is about 1×10 -1 S / cm, about 2×10 -4 S / cm is about 1×10 -1 S / cm, about 2×10 -4 S / cm is about 9×10 -2 S / cm, about 4×10 -4 S / cm is about 9×10 -2 S / cm, about 4×10 -4 S / cm is about 5×10 -2 S / cm, about 5×10 -4 S / cm is about 2×10 -2 S / cm, about 6×10 -4 S / cm is about 1×10 -2 S / cm, about 7×10 -4 S / cm is about 9×10 -3 S / cm, about 8×10 -4 S / cm is about 8×10 -3 S / cm, about 9×10 -4 S / cm is about 7×10 -3S / cm, about 1×10 -3 S / cm is about 7×10 -3 S / cm, about 5×10 -3 S / cm is about 8×10 -3 S / cm, or about 1×10 -3 S / cm is about 5×10 -3 S / cm.

[0156] When the oxide has such a high room-temperature ionic conductivity, the internal resistance of an electrochemical cell including the oxide can be further reduced.

[0157] Since the oxide has high room temperature ionic conductivity, the oxide can be used as a solid electrolyte. The solid electrolyte can be used as a solid electrolyte of an electrochemical cell, or a solid electrolyte of, for example, a lithium secondary battery or an all-solid battery.

[0158] The oxide according to the embodiment may be used as an electrode additive. The oxide according to the embodiment may be electrochemically stable, for example, at a voltage in a range of about 2.0 V to about 4.0 V relative to lithium metal.

[0159] The oxide may be in the form of particles. The average particle diameter of the particles may be, for example, in the range of about 5 nanometers (nm) to about 500 micrometers (μm), or, for example, in the range of about 100 nm to about 100 μm or about 1 μm to about 50 μm; and the specific surface area of ​​the particles may be in the range of about 0.01 m 2 / g to about 1000m 2 / g or for example about 0.5m 2 / g to about 100m 2 The specific surface area can be determined as described in EP Barrett, LG Joyner, PP Halenda, "The determination of pore volume and area distributions in porous substances. I. Computations from nitrogen isotherms", J. Am. Chem. Soc. (1951), 73, 373-380, the contents of which are incorporated herein by reference in their entirety.

[0160] Hereinafter, a method of preparing an oxide according to an embodiment will be described.

[0161] For example, the method of preparing oxides can be explained by using, for example, a solid-state method, but other methods other than the solid-state method such as a spark plasma sintering (discharge plasma sintering) method can be used as the method of preparing oxides, and the method is not limited to the solid-state method.

[0162] Precursors for forming an oxide according to an embodiment may be mixed to prepare a precursor mixture, and the precursor mixture may be heat-treated.

[0163] A precursor mixture is provided for preparing the oxide. The precursor mixture can be prepared, pre-prepared, or purchased.

[0164] During the preparation of the precursor mixture, a metal precursor having a combination of at least four elements may be used as at least one of the M1 precursor, the M2 precursor, and the M3 precursor to obtain the oxide of Formula 1.

[0165] In Formula 1, when y is 0, the precursor mixture may be obtained by mixing a lithium precursor, an M2 precursor, and an M3 precursor. In Formula 1, when z is not 0, a lithium precursor containing X may be further added to the precursor mixture. Examples of the lithium precursor containing X may include LiCl or LiF.

[0166] The precursor mixture can be mixed by using a suitable method such as grinding, blending or sputtering. Examples of grinding can include ball milling, air jet milling, bead milling, roller milling or planetary milling.

[0167] When the precursor mixture is prepared, for example, the mixing can be performed by performing a milling process of a precursor for forming an oxide.

[0168] In the precursor mixture, any suitable material that can dissolve or disperse the lithium precursor, M1 precursor, M2 precursor, and M3 precursor can be used. Examples of solvents may include acetone, ethanol, water, ethylene glycol, isopropanol, or a combination thereof. Based on 100 parts by weight of the total weight of the precursor compound, the amount of the solvent may be in the range of about 50 parts by weight to about 1,000 parts by weight or, for example, about 100 parts by weight to about 300 parts by weight.

[0169] The lithium precursor may be, for example, at least one selected from lithium oxide, lithium carbonate, lithium chloride, lithium sulfate, lithium nitrate, lithium phosphate, and lithium hydroxide.

[0170] Each of the M1 precursor, the M2 precursor, or the M3 precursor may be, for example, at least one selected from hydroxides, carbonates, sulfates, nitrides, oxides, phosphates, and nitrates containing M1, M2, or M3, respectively.

[0171] When the M2 precursor is a lanthanum precursor, examples of the lanthanum precursor may include lanthanum oxide and lanthanum sulfate. When the M2 precursor is a barium precursor, examples of the barium precursor may include barium oxide, barium hydroxide, and barium chloride.

[0172] When the M3 precursor is a zirconium precursor, examples of the zirconium precursor may include zirconium oxide, zirconium sulfate, zirconium carbonate, and zirconium hydroxide. Also, when the M3 precursor is a hafnium precursor, examples of the hafnium precursor may include hafnium oxide, hafnium sulfate, hafnium carbonate, and hafnium hydroxide.

[0173] Examples of the M3 precursor may include tungsten oxide, tungsten carbonate, tungsten chloride, tellurium oxide, tellurium hydroxide, tellurium chloride, selenium oxide, selenium hydroxide, selenium chloride, niobium oxide, niobium hydroxide, niobium chloride, indium oxide, indium chloride, indium hydroxide, indium sulfate, tin oxide, tin chloride, tin hydroxide, scandium oxide, ruthenium oxide, ruthenium chloride, or a combination thereof.

[0174] The amounts of the lithium precursor, the M1 precursor, the M2 precursor, and the M3 precursor may be stoichiometrically selected such that the oxide represented by Formula 1 may be obtained.

[0175] Heat treatment of the precursor mixture may be performed at a temperature in the range of about 600°C to about 1100°C or about 700°C to about 1000°C, and may be performed, for example, for about 1 hour to about 48 hours, about 1 hour to about 30 hours, about 2 hours to about 15 hours, or about 5 hours to about 12 hours.

[0176] When heat treatment is performed within these temperature and time ranges, an oxide having a desired crystal structure can be obtained.

[0177] Subsequently, a molded (molded) product can be obtained from the oxide. The molded product is in the form of, for example, powder particles. The size of the molded product (powder particles) obtained by pulverizing can be about 10 μm or less. When the particle size of the pulverized particles is within this range, the particle size is small enough so that the pulverization and mixing of the particles can be fully carried out, which can promote the formation of a crystalline phase.

[0178] As used herein, the term "size" may refer to an average diameter when the particles have a spherical shape, and may refer to a longitudinal length when the particles do not have a spherical shape. The size may be measured by using an electron scanning microscope or a particle size analyzer.

[0179] The molded product may be subjected to additional heat treatment. The rate of temperature increase of the heat treatment may be in the range of about 1°C / minute to about 10°C / minute. Additional heat treatment, such as secondary heat treatment, may be performed at a temperature in the range of about 900°C to about 1500°C or, for example, about 1000°C to about 1200°C. The heat treatment temperature (T 2 ) may be higher than the heat treatment temperature (T 1 ).

[0180] As described above, when the heat treatment is performed at a high temperature, an oxide obtained therefrom may have a high density.

[0181] In an embodiment, before the heat treatment of the molded product as described above, pressure may be applied to the molded product. For example, the molded product may be prepared in the form of a sheet (disk) by subjecting the molded product to a uniaxial pressurization process. When the molded product in sheet form is heat treated, the distance for diffusing the material to be heat treated is shortened, and thus the desired oxide may be prepared. When heat treatment is applied to powder particles (i.e., not in sheet form), oxides may be produced, but longer heat treatment times and higher temperatures may be used because the diffusion distance in the powder particles is increased compared to the diffusion distance in sheet form.

[0182] Furthermore, the heat treatment can be performed by covering the heat-treated molded product (powder) on top of the sheet. When the oxide is heat-treated in this manner, volatilization of lithium from the sheet or change in composition can be prevented.

[0183] The heat treatment of the molded product and the sheet can be carried out, for example, in an oxidizing gas atmosphere, a reducing gas atmosphere or an inert gas atmosphere. The oxidizing gas atmosphere can be prepared by using, for example, air or oxygen; and the reducing gas atmosphere can be prepared by using, for example, a reducing gas such as hydrogen and an inert gas such as nitrogen, argon or helium.

[0184] The heat treatment time of the molded product and the sheet may vary depending on the heat treatment temperature, and may be in the range of about 1 hour to about 50 hours, or, for example, about 2 hours to about 10 hours.

[0185] Furthermore, according to another aspect of the embodiment, an electrochemical device includes the oxide. The electrochemical device may be an electrochemical cell, a storage battery, a supercapacitor, a fuel cell, a sensor, or a color-changing element.

[0186] According to another aspect, an electrochemical cell includes: a positive electrode; a negative electrode; and a solid electrolyte disposed between the positive electrode and the negative electrode and including the oxide.

[0187] The electrochemical cell may include: a positive electrode; a negative electrode including lithium; and a solid electrolyte disposed between the positive electrode and the negative electrode and including the oxide. The solid electrolyte may further include a binder.

[0188] The electrochemical cell may be a lithium secondary battery, a lithium air battery or an all-solid battery. Moreover, the electrochemical cell may be used for both primary and secondary batteries. The shape of the electrochemical cell is not particularly limited, and examples of the shape may include coins, buttons, sheets, piles, cylinders, plates, and cones. The electrochemical cell according to an embodiment may be applied to medium to large batteries for electric vehicles.

[0189] The electrochemical cell may be, for example, an all-solid battery including a conventional negative electrode active material or an all-solid battery using a deposited negative electrode.

[0190] The deposited negative electrode refers to a negative electrode that has a negative electrode coating free of negative electrode active materials when the electrochemical cell is assembled, but on which negative electrode materials such as lithium metal are deposited after charging of the electrochemical cell.

[0191] The solid electrolyte may be in the form of a protective layer, wherein the protective layer is on the positive electrode, the negative electrode, or a combination thereof.

[0192] The solid electrolyte according to the embodiment can be used as a positive electrode protective layer in a battery using a sulfide-based solid electrolyte, and the reaction between the sulfide-based solid electrolyte and the positive electrode can be reduced. Moreover, the solid electrolyte according to the embodiment can be used as a positive electrode coating material and thus as a positive electrode protective layer. Moreover, the solid electrolyte has a high oxidation potential, which can be used as a positive electrode electrolyte or, for example, in an all-solid battery cathode electrolyte (positive electrode electrolyte).

[0193] According to an embodiment, the electrochemical cell may be an all-solid-state cell.

[0194] The structure of the all-solid secondary battery 1 is shown in Figure 4 The all-solid secondary battery 1 may include a positive electrode 10, a negative electrode 20, and a solid electrolyte 30 containing the oxide.

[0195] The positive electrode 10 may include a positive electrode collector 11 and a positive electrode active material layer 12. The positive electrode collector 11 may be a plate or foil formed of, for example, indium (In), copper (Cu), magnesium (Mg), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), aluminum (Al), germanium (Ge), lithium (Li), or an alloy thereof. The positive electrode collector 11 may be omitted.

[0196] The positive electrode active material layer 12 may include a positive electrode active material and a solid electrolyte. Also, the solid electrolyte included in the positive electrode 10 may be similar to (the same as) or different from the solid electrolyte included in the solid electrolyte 30.

[0197] The positive electrode active material may be a positive electrode active material capable of reversibly intercalating and deintercalating lithium ions.

[0198] For example, the positive electrode active material can be formed by using lithium cobalt oxide (hereinafter, also referred to as "LCO"), lithium nickel oxide, lithium nickel cobalt oxide, lithium nickel cobalt aluminum oxide (hereinafter, also referred to as "NCA"), lithium nickel cobalt manganese oxide (hereinafter, also referred to as "NCM"), lithium manganate, lithium salts such as lithium iron phosphate, nickel sulfide, copper sulfide, lithium sulfide, iron oxide, or vanadium oxide. Examples of the positive electrode active material may be used alone or as a combination of at least two selected therefrom.

[0199] The positive electrode active material may be, for example, LiNi x Coy Al z O 2 (NCA) or LiNi x Co y Mn z O 2 A lithium salt of a ternary transition metal oxide (NCM) (where 0 < x < 1, 0 < y < 1, 0 < z < 1, and x + y + z = 1).

[0200] The positive electrode active material may be covered with a coating layer. Here, the coating layer may be any material that can be used as a coating layer for the positive electrode active material of the all-solid-state secondary battery according to the embodiment. Examples of the coating layer may include Li 2 O-ZrO 2 .

[0201] Moreover, the positive electrode active material may be formed of a lithium salt of a ternary transition metal such as NCA or NCM. The all-solid-state secondary battery 1 using the positive electrode active material may have improved long-term stability and improved cycling characteristics.

[0202] Here, the shape of the positive electrode active material may be, for example, a particulate shape such as a true spherical shape or an ellipsoidal shape. Moreover, the particle diameter of the positive electrode active material is not particularly limited, but may be within the range applicable to the positive electrode active material of the all-solid-state secondary battery. In addition, the amount of the positive electrode active material of the positive electrode 10 is not particularly limited and may be within a range suitable for the positive electrode of the all-solid-state secondary battery.

[0203] In addition, in addition to the positive electrode active material and the solid electrolyte, additives such as a conductive agent, a binder, a filler, a dispersant, and an ion conductor may be added to the positive electrode 10 at an appropriate ratio.

[0204] Examples of the conductive agent that can be added to the positive electrode 10 may include graphite, carbon black, acetylene black, Ketjen black, carbon fiber, and metal powder. Moreover, examples of the binder that can be added to the positive electrode 10 may include styrene-butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, and polyethylene. Moreover, the filler, the dispersant, and the ion conductor added to the positive electrode 10 may be materials suitable for use in the electrodes of the solid secondary battery.

[0205] The negative electrode 20 may include a negative electrode current collector 21 and a negative electrode coating-free layer 22. Figure 4 The negative electrode coating-free layer 22 shown in may be a suitable negative electrode active material layer.

[0206] For example, the negative electrode coating-free layer 22 may contain a semi-metal such as silicon and carbon and may have a structure in which a conductive binder is disposed around the metal and carbon.

[0207] The thickness of the negative electrode coating 22 may be in the range of about 1 μm to about 20 μm, or about 5 μm to about 15 μm. The negative electrode current collector 21 may be formed of a material that does not react with lithium, i.e., does not form an alloy or compound with lithium. The negative electrode current collector 21 may be formed of, for example, copper (Cu), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), or nickel (Ni). The negative electrode current collector 21 may be formed of any metal selected therefrom alone or may be formed of an alloy or coating material of at least two different metals. The negative electrode current collector 21 may be, for example, a plate-like type or a thin film type.

[0208] Here, if Figure 5 As shown in , the thin layer 24 may be formed on the surface of the negative electrode current collector 21. The thin layer 24 may include an element that can form an alloy of lithium. Examples of elements that can form an alloy of lithium may include gold, silver, zinc, tin, indium, silicon, aluminum, and bismuth. The thin layer 24 may be formed of a single metal selected therefrom or a plurality of types of alloys. When the thin layer 24 is present, Figure 6 The metal layer 23 shown in FIG. 1 can be flat, and the characteristics of the all-solid secondary battery 1 can be further improved.

[0209] Here, the thickness of the thin layer 24 is not limited, but may be in the range of about 1 nm to about 500 nm. When the thickness of the thin layer 24 is within this range, the amount of lithium deposited from the negative electrode 20 may be suitable for providing excellent characteristics of the all-solid secondary battery 1. The thin layer 24 may be formed on the negative electrode current collector 21 by using, for example, vacuum vapor deposition, sputtering, or plating.

[0210] The negative electrode coating-free layer 22 may include a negative electrode active material that forms an alloy or a compound with lithium.

[0211] Examples of negative electrode active materials may include amorphous carbon, gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), or zinc (Zn). Here, examples of amorphous carbon may include carbon black (CB), acetylene black (AB), furnace black (FB), Ketjen black (KB), and graphene.

[0212] The negative electrode coating 22 may include one of these negative electrode active materials or at least two negative electrode active materials selected therefrom. For example, the negative electrode coating 22 may include only amorphous carbon as a negative electrode active material or may include at least one metal such as gold, platinum, palladium, silicon, silver, aluminum, bismuth, tin or zinc. Moreover, the negative electrode coating 22 may include a mixture of amorphous carbon and at least one of gold, platinum, palladium, silicon, silver, aluminum, bismuth, tin or zinc. The mixed weight ratio of amorphous carbon and at least one of gold, platinum, palladium, silicon, silver, aluminum, bismuth, tin or zinc in the mixture may be, for example, in the range of about 10: 1 to about 1: 2. When the negative electrode active material is formed by these materials, the characteristics of the all-solid secondary battery 1 can be improved.

[0213] Here, when the negative electrode active material is at least one selected from gold, platinum, palladium, silicon, silver, aluminum, bismuth, tin or zinc, the particle size (e.g., average particle diameter) of the negative electrode active material may be about 4 μm or less. In this case, the characteristics of the all-solid secondary battery 1 can be improved. Here, the particle diameter of the negative electrode active material may be a median diameter (D50) measured by using, for example, a laser-type particle size distribution analyzer. In the embodiments and comparative examples, the particle diameter is measured using this method. The lower limit of the particle diameter is not particularly limited, but may be about 10 nm or less.

[0214] Moreover, the negative electrode active material may include a mixture of first particles formed of amorphous carbon and second particles formed of metal or semimetal. Examples of metals or semimetals may include gold, platinum, palladium, silicon, silver, aluminum, bismuth, tin or zinc. Here, based on the total weight of the mixture, the amount of the second particles may be in the range of about 8% by weight (wt%) to about 60 wt% or about 10 wt% to about 50 wt%. The characteristics of the all-solid secondary battery 1 including the negative electrode active material can be further improved.

[0215] The thickness of the non-negative electrode coating layer 22 may be in the range of about 1 μm to about 20 μm. When the thickness of the non-negative electrode coating layer 22 is within this range, the characteristics of the all-solid secondary battery 1 may be sufficiently improved. When a binder is used, the non-negative electrode coating layer 22 may easily have an appropriate thickness.

[0216] In the negative electrode-free coating layer 22 , additives used in all-solid batteries such as a filler, a dispersant, and an ion conductive agent may be appropriately added.

[0217] The solid electrolyte may be a solid electrolyte including the oxide, or another solid electrolyte may be used in addition to the solid electrolyte including the oxide.

[0218] The additional solid electrolyte may be formed, for example, of a sulfide-based solid electrolyte material. Examples of sulfide-based solid electrolyte materials may include Li 2 SP 2 S 5 , Li 2 SP 2 S 5 -LiX (wherein X is a halogen, such as I or Cl), Li 2 SP 2 S 5 -Li 2 O. Li 2 SP 2 S 5 -Li 2 O-LiI、Li 2 S-SiS 2 , Li2 S-SiS 2 -LiI, Li 2 S-SiS 2 -LiBr, Li 2 S-SiS 2 -LiCl, Li 2 S-SiS 2 -B 2 S 3 -LiI, Li 2 S-SiS 2 -P 2 S 5 -LiI, Li 2 SB 2 S 3 , Li 2 SP 2 S 5 -Z m S n (wherein m and n are positive integers, and Z is Ge, Zn or Ga), Li 2 S-GeS 2 , Li 2 S-SiS 2 -Li 3 PO 4 , or Li 2 S-SiS 2 -Li p MO q (wherein p and q are positive integers, and M is P, Si, Ge, B, Al, Ga or In). Here, the sulfide-based solid electrolyte material is prepared by: 2 S or P 2 S 5 ) is melted and quenched, or the starting material is mechanically ground. Subsequently, the resultant may be heat treated. The solid electrolyte may be amorphous or crystalline, and may be a mixed form thereof.

[0219] Furthermore, the solid electrolyte 30 may include sulfur (S), phosphorus (P), lithium (Li), or a combination thereof as a constituent element in the sulfide-based solid electrolyte material, and for example, Li 2 SP 2 S 5 can be used as a solid electrolyte 30. Here, when Li 2 SP 2 S 5 When used as a sulfide-based solid electrolyte material forming the solid electrolyte 30, Li 2 S and P 2 S 5 The molar ratio (Li 2S:P 2 S 5 ) can be selected, for example, in the range of about 50:50 to about 90:10. Moreover, the solid electrolyte layer 30 may further include a binder. The binder included in the solid electrolyte layer 30 may be styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, or polyethylene. The binder included in the solid electrolyte layer 30 may be the same as or different from the binder included in the positive electrode active material layer 12 and the negative electrode coating layer 22.

[0220] One or more embodiments will now be described in more detail with reference to the following examples. However, these examples are not intended to limit the scope of the disclosed embodiments.

[0221] Example

[0222] Preparation of oxides

[0223] Example 1

[0224] Li as a lithium precursor 2 O, La as a lanthanum precursor 2 O 3 , ZrO as a zirconium precursor 2 , HfO as a hafnium precursor 2 Sc as a scandium precursor 2 O 3 , Nb as a niobium precursor 2 O 5 and SnO as a tin precursor 2 The precursors were mixed in a stoichiometric ratio according to the composition ratio of the oxides shown in Table 1. The precursors were mixed for 10 minutes using a planetary mill (Pulverisette 7 premium line) with zirconia balls and rested for 5 minutes. These grinding and resting processes were repeated 12 times to obtain a precursor mixture.

[0225] The precursor mixture was put into an alumina furnace and subjected to a heat treatment at a temperature of about 1000° C. for 12 hours at a temperature increase rate of about 5° C. / min to obtain an oxide.

[0226] Table 1

[0227]

[0228]

[0229] Example 2

[0230] The oxide was prepared in the same manner as in Example 1, except that Li 2 O.La 2 O 3 、ZrO2 , HfO 2 、In 2 O 3 and Nb 2 O 5 As a precursor mixture instead of Li 2 O.La 2 O 3 、ZrO 2 , HfO 2 Sc 2 O 3 , Nb 2 O 5 and SnO 2 mixture.

[0231] Example 3

[0232] The oxide was prepared in the same manner as in Example 1, except that Li 2 O.La 2 O 3 、ZrO 2 , HfO 2 Sc 2 O 3 and Nb 2 O 5 As a precursor mixture instead of Li 2 O.La 2 O 3 、ZrO 2 , HfO 2 Sc 2 O 3 , Nb 2 O 5 and SnO 2 mixture.

[0233] Example 4

[0234] The oxide was prepared in the same manner as in Example 1, except that Li 2 O.La 2 O 3 、ZrO 2 , HfO 2 SnO 2 , and RuO 2 As a precursor mixture instead of Li 2 O.La 2 O 3 、ZrO 2 , HfO 2 Sc 2 O 3 , Nb 2 O5 and SnO 2 mixture.

[0235] Example 5

[0236] The oxide was prepared in the same manner as in Example 1, except that Li 2 O, BaO, La 2 O 3 、ZrO 2 , HfO 2 、In 2 O 3 , Nb 2 O 5 and SnO 2 As a precursor mixture instead of Li 2 O.La 2 O 3 、ZrO 2 , HfO 2 Sc 2 O 3 , Nb 2 O 5 and SnO 2 mixture.

[0237] Example 6

[0238] The oxide was prepared in the same manner as in Example 1, except that Li 2 O, BaO, La 2 O 3 、ZrO 2 , HfO 2 Sc 2 O 3 , Nb 2 O 5 and SnO 2 As a precursor mixture instead of Li 2 O.La 2 O 3 、ZrO 2 , HfO 2 Sc 2 O 3 , Nb 2 O 5 and SnO 2 mixture.

[0239] Example 7

[0240] The oxide was prepared in the same manner as in Example 1, except that Li 2 O.La 2 O 3、ZrO 2 , HfO 2 Sc 2 O 3 SnO 2 , Nb 2 O 5 and LiF as a precursor mixture to replace Li 2 O.La 2 O 3 、ZrO 2 , HfO 2 Sc 2 O 3 , Nb 2 O 5 and SnO 2 The amount of LiF was controlled according to the stoichiometric ratio of the composition ratio in Table 1.

[0241] Embodiment 8-19

[0242] The oxide was prepared in the same manner as in Example 1, except that the molar mixing ratio of each of the precursors was changed so that the oxide having the composition shown in Table 2 was obtained.

[0243] Table 2

[0244] sample composition Example 8 <![CDATA[Li 7 La 3 Zr 0.3 Hf 0.5 Sc 0.3 Nb 0.5 Sn 0.4 O 12 ]]> Example 9 <![CDATA[Li 7 La 3 Zr 0.4 Hf 0.6 In 0.4 Nb 0.6 O 12 ]]> Example 10 <![CDATA[Li 7 La 3 Zr 0.4 Hf 0.6 Sc 0.4 Nb 0.6 O 12 ]]> Embodiment 11 <![CDATA[Li 7 The 3 Zr 0.4 Hf 0.6 Sn 0.4 Ru 0.6 Oh 12 ]]> Example 12 <![CDATA[Li 7.1 La 2.9 Ba 0.1 Zr 0.3 Hf 0.5 In 0.3 Nb 0.5 Sn 0.4 O 12 ]]> Example 13 <![CDATA[Li 7.1 La 2.9 Ba 0.1 Zr 0.5 Hf 0.3 In 0.5 Nb 0.3 Sn 0.4 O 12 ]]> Embodiment 14 <![CDATA[Li 7.1 La 2.9 Ba 0.1 Zr 0.3 Hf 0.5 Sc 0.3 Nb 0.5 Sn 0.4 O 12 ]]> Embodiment 15 <![CDATA[Li 6.8 La 3 Zr 0.3 Hf 0.5 Sn 0.3 Sc 0.5 Nb 0.4 O 11.8 F 0.2 ]]> Example 16 <h2 style=";text-align:left;direction:ltr"><![CDATA[Li <h2 style=";text-align:left;direction:ltr"> 7 <h2 style=";text-align:left;direction:ltr"> No<h2 style=";text-align:left;direction:ltr"> 3 <h2 style=";text-align:left;direction:ltr"> Zr<h2 style=";text-align:left;direction:ltr"> 0.4 <h2 style=";text-align:left;direction:ltr"> Hf<h2 style=";text-align:left;direction:ltr"> 0.4 <h2 style=";text-align:left;direction:ltr"> Al<h2 style=";text-align:left;direction:ltr"> 0.4 <h2 style=";text-align:left;direction:ltr"> Nb<h2 style=";text-align:left;direction:ltr"> 0.4 <h2 style=";text-align:left;direction:ltr"> Sn<h2 style=";text-align:left;direction:ltr"> 0.4 <h2 style=";text-align:left;direction:ltr"> O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ]]><h2 style=";text-align:left;direction:ltr"> Embodiment 17 <![CDATA[Li 7.0 La 2.9 Y 0.1 Zr 0.4 Hf 0.4 Sc 0.4 Nb 0.4 Sn 0.4 O 12 ]]> Embodiment 18 <h2 style=";text-align:left;direction:ltr"><![CDATA[Li <h2 style=";text-align:left;direction:ltr"> 7 <h2 style=";text-align:left;direction:ltr"> No<h2 style=";text-align:left;direction:ltr"> 3 <h2 style=";text-align:left;direction:ltr"> Zr<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Hf<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Al<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Nb<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ]]><h2 style=";text-align:left;direction:ltr"> Embodiment 19 <![CDATA[Li 6.8 La 3 Zr 0.4 Hf 0.4 Sn 0.4 Sc 0.4 Nb 0.4 O 11.8 Cl 0.2 ]]>

[0245] Comparative Example 1

[0246] The oxide was prepared in the same manner as in Example 1, except that Li 2 O.La 2 O 3 and HfO 2 As a precursor mixture instead of Li 2 O.La 2 O 3 、ZrO 2 , HfO 2 Sc 2 O 3 , Nb 2 O 5 and SnO 2 mixture.

[0247] Comparative Example 2

[0248] The oxide was prepared in the same manner as in Example 1, except that Li 2 O.La 2 O 3 、ZrO 2 , HfO 2 and SnO 2As a precursor mixture instead of Li 2 O.La 2 O 3 、ZrO 2 , HfO 2 Sc 2 O 3 , Nb 2 O 5 and SnO 2 mixture.

[0249] Comparative Example 3Li 6.5 La 3 Zr 1.5 Nb 0.5 O 12

[0250] The oxide was prepared in the same manner as in Example 1, except that Li 2 O.La 2 O 3 、ZrO 2 and Nb 2 O 3 As a precursor mixture instead of Li 2 O.La 2 O 3 、ZrO 2 , HfO 2 Sc 2 O 3 , Nb 2 O 5 and SnO 2 mixture.

[0251] The oxide according to Comparative Example 3 has a relatively reduced amount of lithium, and thus exhibits reduced interfacial stability between the oxide and lithium metal when the oxide is disposed on lithium metal.

[0252] Evaluation Example 1: X-ray Diffraction (XRD) Analysis Spectrum

[0253] The XRD spectra of the oxides prepared in Examples 1 and 3 and Comparative Examples 1 and 2 were obtained and the results are shown in Figure 2A and 2B middle. Figure 2B for Figure 2A An enlarged view of a portion of . The X-ray diffraction analysis was performed by using D8 Advance available from Bruker, and Cu Kα radiation was used in the measurement of the XRD spectrum.

[0254] refer to Figure 2AThe XRD pattern analysis shows that the oxides prepared in Examples 1 and 3 have the same garnet crystal structure as the oxides prepared in Comparative Examples 1 and 2, and the Figure 2B , it can be shown that the oxides of Examples 1 and 3 have a cubic phase.

[0255] like Figure 2B As shown in , the oxides of Examples 1 and 3 have a single peak at a diffraction angle 2θ in the range of about 16° to about 17.5°, which indicates that the oxides of Examples 1 and 3 have a garnet crystal structure including a cubic phase. In the oxides of Examples 1 and 3, the configuration entropy increases to stabilize the cubic phase. The cubic phase has increased ion conductivity.

[0256] The oxides of Comparative Examples 1 and 2 have multiple peaks as split peaks determined by XRD spectrum analysis at a diffraction angle 2θ in the range of about 16° to about 17.5°, which indicates that, unlike the oxides of Examples 1 and 3, the oxides of Comparative Examples 1 and 2 have a garnet crystal structure including a tetragonal phase.

[0257] From the XRD analysis, it was confirmed that the oxides of Examples 1 and 3 had a garnet structure including a cubic phase, which was stable at high temperatures due to an increase in configuration entropy.

[0258] Evaluation Example 2: Measurement of ion conductivity and activation energy

[0259] 1.5 g of the oxides prepared in Examples 1 to 7 and Comparative Examples 1 and 2 were each put into a sheet having a diameter of 1 inch, and the oxide was pressed by applying a weight of 5 tons for 2 minutes using a uniaxial press, and thereby a disc-shaped sheet was prepared. The sheet was placed on a MgO single crystal, and the periphery of the sheet was covered with a primary heat-treated oxide powder to prevent lithium volatilization and composition change. Then, the sheet was heat-treated at a temperature of 1200° C. for 4 hours at a temperature increase rate of 5° C. / min.

[0260] The sheet obtained after the secondary heat treatment process was subjected to mirror polishing by sequentially using 1200 / 2000 / 4000 / 7000 sandpaper, and Au electrodes were formed by depositing Au having a diameter of 8 mm on both surfaces of the sheet by sputtering using a sputtering device, thereby completing the preparation of an assembly including Au electrode / oxide sheet / Au electrode

[0261] In an assembly including Au electrode / oxide sheet / Au electrode, a wire was connected to each of the Au electrodes on both surfaces of the sheet and analyzed using electronic impedance spectroscopy (EIS). The amplitude was about 10 millivolts (mV) and the range was about 0.1 Hz to about 10 6 Hz frequency for EIS analysis.

[0262] The results of EIS evaluation are shown in Table 3. The total resistance (R 总 ) value, and the electrode surface area and sheet thickness were corrected based on the total resistance value to calculate the conductivity value. Also, during the EIS measurement, the activation energy E for Li ion conduction was calculated from the results measured by changing the temperature of the chamber of each sample loaded with oxide. a The conductivity values ​​measured at temperatures in the range of about 298 K to about 378 K were converted into an Arrhenius plot using Equation 2, so that the activation energy E was calculated from the slope value determined from the Arrhenius plot. a .

[0263] Equation 2

[0264] σT=A exp(E a / RT)

[0265] In equation 2, E a denotes activation energy, T denotes absolute temperature, A denotes preexponential factor, R denotes gas constant, and σ denotes conductivity.

[0266] The results of the activation energy analysis are shown in Table 3 and Figures 3A to 3D middle.

[0267] Table 3

[0268]

[0269]

[0270] As shown in Table 3, it can be known that the oxides prepared in Examples 1 to 7 have improved ion conductivities at room temperature (25° C.) compared to those of the oxides prepared in Comparative Examples 1 and 2.

[0271] Moreover, as shown in Table 3 and Figures 3A to 3D As shown in , the activation energy of the oxides of Comparative Examples 1 and 2 ( Figure 3C and 3D ), the oxides of Examples 1 and 3 have smaller values. When the activation energy of the oxide is lowered like this, as a result, the ion conductivity at low temperature can be improved.

[0272] refer to Figure 3C In the oxide of Comparative Example 1, the garnet composition (Li x M1 y )(M2) 3 (M3) 2 A 12The number N of elements located at the M3 position in the composition is 1, where Hf is introduced into the composition. As a result of measuring the ionic conductivity, it was confirmed that 1.7×10 -6 S / cm ionic conductivity (where activation energy is E a =459.5 millielectron volts (meV)). As in Comparative Example 2 when N=3, the configuration entropy is insufficient to stabilize the cubic phase, and thus it is confirmed that the oxide of Comparative Example 1 has a tetragonal phase when N is 1, which leads to a sharp decrease in ionic conductivity.

[0273] refer to Figure 3D , the oxide of Comparative Example 2 is when the garnet composition (Li x M1 y )(M2) 3 (M3) 2 A 12 The case where the number N of elements located at the M3 position is 3, wherein Zr, Hf and Sn are introduced into the composition. Figure 3D As shown in FIG. , it is confirmed that the oxide of Comparative Example 2 has a 1.7×10 -6 S / cm ionic conductivity at room temperature (where the activation energy is E a =510.6 meV). When N is less than 4, the configuration entropy is insufficient to stabilize the cubic phase, and thus it is confirmed that the oxide has a tetragonal phase, which leads to a rapid decrease in ionic conductivity.

[0274] Furthermore, the ionic conductivity and activation energy of the oxides of Examples 8 to 15 were analyzed in the same manner as the ionic conductivity and activation energy of the oxides of Examples 1 to 7 were measured.

[0275] As a result of the analysis, the oxides of Examples 8 to 19 each had similar ion conductivity and activation energy to those of the oxides of Examples 1 to 7, respectively.

[0276] Evaluation Example 3: Inductively Coupled Plasma Analysis

[0277] The oxides prepared according to Examples 1, 3, and 4 were subjected to inductively coupled plasma analysis, and the results of the analysis are shown.

[0278] Inductively coupled plasma analysis was performed using ICPS-8100 available from SHIMADZU.

[0279] Referring to inductively coupled plasma analysis, the composition of each element of the oxides prepared in Examples 1 to 3 was confirmed.

[0280] As described above, according to one or more embodiments, the oxide may have excellent lithium metal stability and improved ion conductivity. When the oxide is used, an electrochemical device with improved performance may be prepared.

[0281] It should be understood that the embodiments described herein should be considered in a descriptive sense only and not for limiting purposes. The description of features, aspects, or advantages in each embodiment should be considered to be applicable to other similar features, aspects, or advantages in other embodiments. Although one or more embodiments have been described with reference to the accompanying drawings, it will be understood by those of ordinary skill in the art that various changes in form and detail may be made therein without departing from the spirit and scope as defined by the appended claims.

Claims

1. An oxide comprising a compound represented by Formula 1: Formula 1 <h2 style=";text-align:left;direction:ltr">(Li<h2 style=";text-align:left;direction:ltr"> x <h2 style=";text-align:left;direction:ltr"> M1<h2 style=";text-align:left;direction:ltr"> y <h2 style=";text-align:left;direction:ltr"> (M2)<h2 style=";text-align:left;direction:ltr"> 3-δ <h2 style=";text-align:left;direction:ltr"> (M3)<h2 style=";text-align:left;direction:ltr"> 2-ω <h2 style=";text-align:left;direction:ltr"> O<h2 style=";text-align:left;direction:ltr"> 12-z <h2 style=";text-align:left;direction:ltr"> X<h2 style=";text-align:left;direction:ltr"> z in, In Formula 1, 6 ≤ x ≤ 8, 0 ≤ y < 2, -0.2 ≤ δ ≤ 0.2, -0.2 ≤ ω ≤ 0.2, and 0 ≤ z ≤ 2; M1 is a monovalent cation, divalent cation, trivalent cation, or a combination thereof; M2 is a monovalent cation, divalent cation, trivalent cation, or a combination thereof; M3 is a monovalent cation, divalent cation, trivalent cation, tetravalent cation, pentavalent cation, hexavalent cation, or a combination thereof; wherein at least one of M1, M2, or M3 comprises at least four elements; and X is a monovalent anion, divalent anion, trivalent anion, or a combination thereof, wherein the compound represented by Formula 1 is a compound represented by Formula 2: Formula 2 (Li x M1 y )(The a1 M4 a2 ) 3-δ (M5 b1 M6 b2 M7 b3 M8 b4 M9 b5 ) 2-ω About 12-z X z wherein, in Formula 2, M1 is hydrogen, iron, gallium, aluminum, boron, beryllium, or a combination thereof, M4 is barium, calcium, strontium, yttrium, bismuth, praseodymium, neodymium, actinium, samarium, gadolinium, or a combination thereof, and M5 to M9 are each independently zirconium, hafnium, tin, niobium, titanium, vanadium, chromium, manganese, cobalt, nickel, copper, molybdenum, tungsten, tantalum, magnesium, technetium, ruthenium, palladium, iridium, scandium, cadmium, indium, antimony, tellurium, thallium, platinum, silicon, aluminum, or a combination thereof; 6 ≤ x ≤ 8, 0 ≤ y < 2, -0.2 ≤ δ ≤ 0.2, -0.2 ≤ ω ≤ 0.2, and 0 ≤ z ≤ 2; a1 + a2 = 1, 0 < a1 ≤ 1, and 0 ≤ a2 < 1; b1 + b2 + b3 + b4 + b5 = 1, 0 < b1 < 1, 0 < b2 < 1, 0 < b3 < 1, 0 < b4 < 1, and 0 ≤ b5 < 1; and X is iodine, chlorine, bromine, fluorine, cyanide, cyanate, thiocyanate, azide, or a combination thereof, and M5 to M9 are different from each other.

2. The oxide according to claim 1, wherein at least one of M1 and M2 comprises at least one element, and M3 comprises at least four elements.

3. The oxide according to claim 1, wherein at least one of M1 or M2 comprises at least two elements, and M3 comprises at least four elements.

4. The oxide according to claim 1, wherein M3 comprises the following combinations: Four tetravalent cations; Two tetravalent cations, one trivalent cation, and one pentavalent cation; Two tetravalent cations, one divalent cation, and one hexavalent cation; Three tetravalent cations, one trivalent cation, and one pentavalent cation; Three tetravalent cations, one divalent cation, and one hexavalent cation; One tetravalent cation, two trivalent cations, and two pentavalent cations; Four tetravalent cations, one trivalent cation, and one pentavalent cation; Four tetravalent cations, one divalent cation, and one hexavalent cation; Two tetravalent cations, two trivalent cations, and two pentavalent cations; or Two tetravalent cations, two divalent cations, and two hexavalent cations.

5. The oxide according to claim 1, wherein when analyzed by X-ray diffraction using Cu Kα radiation, the oxide has a single peak at a diffraction angle of 16° 2θ to 20° 2θ.

6. The oxide according to claim 1, wherein the oxide has a garnet structure including a cubic phase.

7. The oxide of claim 1, wherein the lithium ion conductivity of the oxide at 25°C is at least 1×10 -4 Siemens / cm.

8. The oxide according to claim 1, wherein the compound represented by Formula 1 is the compound represented by Formula 3: Formula 3 There x (There a1 M10 a2 ) 3-δ (M11 b1 M12 b2 M13 b3 M14 b4 M15 b5 ) 2-ω OR 12-z X z in, In Formula 3, M10 is barium, calcium, strontium, yttrium, bismuth, praseodymium, neodymium, actinium, samarium, gadolinium, or a combination thereof, M11 is zirconium, hafnium, or a combination thereof, and each of M12 to M15 is independently zirconium, hafnium, tin, niobium, titanium, vanadium, chromium, manganese, cobalt, nickel, copper, molybdenum, tungsten, tantalum, magnesium, technetium, ruthenium, palladium, iridium, scandium, cadmium, indium, antimony, tellurium, thallium, platinum, silicon, aluminum, or a combination thereof; 6 ≤ x ≤ 8, -0.2 ≤ δ ≤ 0.2, -0.2 ≤ ω ≤ 0.2, and 0 ≤ z ≤ 2; a1 + a2 = 1, 0 < a1 ≤ 1, and 0 ≤ a2 < 1; b1 + b2 + b3 + b4 + b5 = 1, 0 < b1 < 1, 0 < b2 < 1, 0 < b3 < 1, 0 < b4 < 1, and 0 < b5 < 1; and X is iodine, chlorine, bromine, fluorine, cyanide, cyanate, thiocyanate, azide, or a combination thereof, and M12 to M15 are different from each other.

9. The oxide according to claim 8, wherein In Formula 3, M10 is barium, M11 is zirconium, M12 is hafnium, and each of M13 to M15 is independently tin, niobium, titanium, vanadium, chromium, manganese, cobalt, nickel, copper, molybdenum, tungsten, tantalum, magnesium, technetium, ruthenium, palladium, iridium, scandium, cadmium, indium, antimony, tellurium, thallium, platinum, silicon, or a combination thereof; and z is 0, or X is fluorine or chlorine.

10. The oxide according to claim 8, wherein each of M13 to M15 is independently tin, niobium, scandium, indium, or a combination thereof, and z is 0, or X is fluorine or chlorine.

11. The oxide according to claim 1, wherein In Formula 1, M2 is lanthanum, barium, or a combination thereof, M3 includes at least four elements selected from zirconium, hafnium, tin, niobium, scandium, or indium, and z is 0, or X is fluorine.

12. The oxide according to claim 1, wherein the oxide is Li x LqCy b1 Hf b2 Sc b3 Nb b4 Sn b5 O 12 , where 6≤x≤8, b1+b2+b3+b4+b5=2,0 <b1<1, 0 < b2 < 1, 0 < b3 < 1, 0 < b4 < 1, and 0 < b5 < 1, Li x LqCy b1 Hf b2 In b3 Nb b4 O 12 , where 6≤x≤8, b1+b2+b3+b4=2,0 <b1<1, 0 < b2 < 1, 0 < b3 < 1, and 0 < b4 < 1, Li x LqCy b1 Hf b2 Sc b3 Nb b4 O 12 , where 6≤x≤8, b1+b2+b3+b4=2,0 <b1<1, 0 < b2 < 1, 0 < b3 < 1, and 0 < b4 < 1, Li x LqCy b1 Hf b2 Sn b3 Ru b4 O 12 , where 6≤x≤8, b1+b2+b3+b4=2,0 <b1<1, 0 < b2 < 1, 0 < b3 < 1, and 0 < b4 < 1, Li x La a1 Ba a2 Zr b1 Hf b2 In b3 Nb b4 Sn b5 O 12 , where 6≤x≤8, a1+a2=3, b1 + b2 + b3 + b4 + b5 = 2, 0 < a1 < 3, 0 < a2 < 3, 0 < b1 < 1, 0 < b2 < 1, 0 < b3 < 1, 0 < b4 < 1, and 0 < b5 < 1, Li x La a1 Ba a2 Zr b1 Hf b2 Sc b3 Nb b4 Sn b5 O 12 , where 6≤x≤8, a1+a2=3, b1 + b2 + b3 + b4 + b5 = 2, 0 < a1 < 3, 0 < a2 < 3, 0 < b1 < 1, 0 < b2 < 1, 0 < b3 < 1, 0 < b4 < 1, and 0 < b5 < 1, Li x LqCy b1 Hf b2 Sn b3 Sc b4 Nb b5 O 12-z F z , where 6≤x≤8, b1+b2+b3+b4+b5=2, 0 < b1 < 1, 0 < b2 < 1, 0 < b3 < 1, 0 < b4 < 1, 0 < b5 < 1, and 0 ≤ z ≤ 2, Li x LqCy b1 Hf b2 Sn b3 Sc b4 Nb b5 O 12-z Cl z , where 6≤x≤8, b1+b2+b3+b4+b5=2, 0 ≤ z ≤ 2, 0 < b1 < 1, 0 < b2 < 1, 0 < b3 < 1, 0 < b4 < 1, and 0 < b5 < 1, or a combination thereof.

13. The oxide according to claim 1, wherein the oxide is Li7La3Zr 0.4 Hf 0.4 Sc 0.4 Nb 0.4 Sn 0.4 O 12 ,Li7La3Zr 0.3 Hf 0.5 Sc 0.3 Nb 0.5 Sn 0.4 O 12 ,Li7La3Zr 0.5 Hf 0.3 Sc 0.5 Nb 0.3 Sn 0.4 O 12 ,Li7La3Zr 0.3 Hf 0.5 Sc 0.4 Nb 0.3 Sn 0.5 O 12 ,Li7La3Zr 0.5 Hf 0.3 Sc 0.4 Nb 0.5 Sn 0.3 O 12 ,Li7La3Zr 0.5 Hf 0.5 In 0.5 Nb 0.5 O 12 ,Li7La3Zr 0.4 Hf 0.6 In 0.4 Nb 0.6 O 12 ,Li7La3Zr 0.6 Hf 0.4 In 0.6 Nb 0.4 O 12 ,Li7La3Zr 0.4 Hf 0.4 In 0.6 Nb 0.6 O 12 ,Li7La3Zr 0.6 Hf 0.6 In 0.4 Nb 0.4 O 12 ,Li7La3Zr 0.5 Hf 0.5 Sc 0.5 Nb 0.5 O 12 ,Li7La3Zr 0.4 Hf 0.6 Sc 0.4 Nb 0.6 O 12 ,Li7La3Zr 0.6 Hf 0.4 Sc 0.6 Nb 0.4 O 12 ,Li7La3Zr 0.4 Hf 0.4 Sc 0.6 Nb 0.6 O 12 ,Li7La3Zr 0.6 Hf 0.6 Sc 0.4 Nb 0.4 O 12 ,Li7La3Zr 0.5 Hf 0.5 Sn 0.5 Ru 0.5 O 12 ,Li7La3Zr 0.4 Hf 0.6 Sn 0.4 Ru 0.6 O 12 ,Li7La3Zr 0.6 Hf 0.4 Sn 0.6 Ru 0.4 O 12 ,Li7La3Zr 0.4 Hf 0.4 Sn 0.6 Ru 0.6 O 12 ,Li7La3Zr 0.6 Hf 0.6 Sn 0.4 Ru 0.4 O 12 ,Li 7.1 La 2.9 Ba 0.1 Zr 0.4 Hf 0.4 In 0.4 Nb 0. 4Sn 0.4 O 12 ,Li 7.1 La 2.9 Ba 0.1 Zr 0.3 Hf 0.5 In 0.3 Nb 0.5 Sn 0.4 O 12 ,Li 7.1 The 2.9 Ba 0.1 Zr 0.5 Hf 0.3 In 0.5 Nb 0.3 Sn 0. 4O 12 ,Li 7.1 The 2.9 Ba 0.1 Zr 0.3 Hf 0.5 In 0.4 Nb 0.3 Sn 0.5 About 12 ,Li 7.1 The 2.9 Ba 0.1 Zr 0.5 Hf 0.3 In 0.4 Nb 0.5 Sn 0.3 About 12 ,Li 7.1 The 2.9 Ba 0.1 Zr 0.4 Hf 0.4 Sc 0.4 Nb 0.4 Sn 0.4 About 12 ,Li 7.1 The 2.9 Ba 0.1 Zr 0.3 Hf 0.5 Sc 0.3 Nb 0.5 Sn 0.4 About 12 ,Li 7.1 The 2.9 Ba 0.1 Zr 0.5 Hf 0.3 Sc 0.5 Nb 0.3 Sn 0.4 About 12 ,Li 7.1 The 2.9 Ba 0.1 Zr 0.3 Hf 0.5 Sc 0.4 Nb 0.3 Sn 0.5 About 12 ,Li 7.1 The 2.9 Ba 0.1 Zr 0.5 Hf 0.3 Sc 0.4 Nb 0.5 Sn 0.3 O 12 ,Li 6.8 La3Zr 0.4 Hf 0.4 Sn 0.4 Sc 0.4 Nb 0.4 O 11.8 F 0.2 ,Li 6.8 La3Zr 0.3 Hf 0.5 Sn 0.3 Sc 0.5 Nb 0.4 O 11.8 F 0.2 ,Li 6.8 La3Zr 0.5 Hf 0.3 Sn 0.5 Sc 0.3 Nb 0.4 O 11.8 F 0.2 ,Li 6.8 La3Zr 0.3 Hf 0.5 Sn 0.4 Sc 0. 3Nb 0.5 O 11.8 F 0.2 ,Li 6.8 La3Zr 0.5 Hf 0.3 Sn 0.4 Sc 0.5 Nb 0.3 O 11.8 F 0.2 ,Li7La3Zr 0.4 Hf 0.4 Al 0.4 Nb 0.4 Sn 0.4 O 12 ,Li 7.0 La 2.9 Y 0.1 Zr 0.4 Hf 0.4 Sc 0.4 Nb 0.4 Sn 0.4 O 12 ,Li7La3Zr 0.5 Hf 0.5 Al 0.5 Nb 0.5 O 12 ,Li 6.8 LqCy 0.4 Hf 0.4 Sn 0.4 Sc 0.4 Nb 0.4 O 11.8 Cl 0.2 , or a combination thereof.

14. A method for preparing the oxide according to any one of claims 1 - 13, the method comprising: providing a precursor mixture comprising a lithium precursor, optionally an M1 precursor, an M2 precursor, an M3 precursor, and optionally an X precursor; and heat - treating the precursor mixture in an oxidizing gas to prepare the compound represented by Formula 1.

15. The method of claim 14, wherein heat treating the precursor mixture comprises heat treating at a temperature of 600°C to 1100°C.

16. The method of claim 14, further comprising grinding the precursor mixture prior to heat treating the precursor mixture.

17. The method of claim 14, further comprising: pressing the heat-treated precursor mixture to form a sheet; and The sheet is heat treated at a temperature in the range of 900°C to 1500°C.

18. The method of claim 17, wherein heat treating the sheet comprises heat treating at a temperature greater than a temperature of heat treating the precursor mixture.

19. Solid electrolytes, including: The oxide according to any one of claims 1 to 13.

20. An electrochemical device comprising: positive electrode; negative electrode; and Solid electrolytes; The positive electrode, the negative electrode, the solid electrolyte, or a combination thereof comprises the oxide according to any one of claims 1 to 13.

21. The electrochemical device of claim 20, wherein the solid electrolyte is between the positive electrode and the negative electrode.

22. The electrochemical device according to claim 20, wherein the solid electrolyte is in the form of a protective layer, and The protective layer is on the positive electrode, the negative electrode, or a combination thereof, or the solid electrolyte is an electrolyte protective layer.

23. The electrochemical device of claim 20, wherein the electrochemical device is an all-solid-state battery.

24. An oxide comprising a compound represented by Formula 1: Formula 1 <h2 style=";text-align:left;direction:ltr">(Li<h2 style=";text-align:left;direction:ltr"> x <h2 style=";text-align:left;direction:ltr"> M1<h2 style=";text-align:left;direction:ltr"> y <h2 style=";text-align:left;direction:ltr"> (M2)<h2 style=";text-align:left;direction:ltr"> 3-δ <h2 style=";text-align:left;direction:ltr"> (M3)<h2 style=";text-align:left;direction:ltr"> 2-ω <h2 style=";text-align:left;direction:ltr"> O<h2 style=";text-align:left;direction:ltr"> 12-z <h2 style=";text-align:left;direction:ltr"> X<h2 style=";text-align:left;direction:ltr"> z in, In formula 1, 6≤x≤8, 0≤y<2, −0.2≤δ≤0.2, −0.2≤ω≤0.2, and 0≤z≤2; M1 is hydrogen, iron, gallium, aluminum, boron, beryllium, or a combination thereof; M2 is lanthanum, barium, or a combination thereof; and M3 is zirconium, hafnium, tin, niobium, scandium, indium, or a combination thereof; wherein at least one of M1, M2 or M3 comprises at least four elements; and X is a halogen, a pseudohalogen, or a combination thereof.

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