Solid halide electrolytes

Abstract

The present invention relates to a solid electrolyte material of the following formula (I), M3Me 1-x In x Cl 6-y Br y , Here, M includes alkali metal elements, particularly lithium (Li), Me is a trivalent element selected from Y, Al, Sc, La, Ce, Gd, Er, and Yb, x is greater than 0 and less than 0.50, and y is greater than 1.0 and less than 3.0. The present invention further relates to a production process for obtaining the above-mentioned solid electrolyte material, and to a battery in which at least one of the cathode, anode, and electrolyte layer comprises the above-mentioned solid electrolyte material.

Description

Technical Field

[0001] The present invention belongs to the field of all-solid-state rechargeable batteries (ASSBs), and particularly relates to a new composition of solid electrolytes.

Background Art

[0002] ASSBs have received particular attention as an alternative to conventional Li-ion batteries because, in particular, they have relatively few safety concerns and relatively high capacities.

[0003] To obtain an ASSB, a solid electrolyte is used instead of the liquid electrolyte used in Li-ion batteries. Also, the ASSB uses a lithium metal anode and high-energy NMC cathode particles, which are incorporated into the solid electrolyte.

[0004] Such solid electrolytes are selected from, for example, lithium thiophosphate (β-Li3PS4, LPS), argyrodite (Li6PS5Cl), such as those described in "Li6PS5X: A Lithium-Rich Crystalline Solid with Very High Li+ Mobility" by H.J. Deiseroth et al. (Angew. Chem. Int. Ed., 47 (2008), pp. 755-758), and halides, such as Li3InCl6, such as those described below: "Air-Stable Li3InCl6 Electrolyte with High-Voltage Compatibility for All-Solid-State Batteries" by X. Li et al. (Energy Environ. Sci., 2019, 12, pp. 2665-267); "Zur Kristallstruktur von Li3InCl6." by Schmidt, M.O. et al. (Zeitschrift fur Anorg. und Allg. 19,99, 625(4), 539-540; and "Handbook of Physics and Chemistry of Rare Earths" by G. Meyer et al. (V. 28, Chapter 177, 2000 Elsevier Sci.).

[0005] However, the main drawback of these compounds is their chemical and electrochemical interactions with electrode materials.

[0006] Halide solid electrolytes are attracting particular attention because they exhibit good ionic conductivity (greater than 2 mS / cm), high electrochemical stability against oxidation on the cathode side, and better processability (deformability) than other inorganic solid electrolytes.

[0007] However, while halide solid electrolytes exhibit good electrochemical resistance to high-energy NMC cathodes, they also have the disadvantage of being highly hygroscopic. Thus, they are unstable in the presence of trace amounts of water, which leads to highly complex applications on an industrial scale.

[0008] Furthermore, in European Patent Application Publication No. 3736830, the formula Li3YBr is given for 0.5 ≤ x ≤ 5. 6-x Cl x It has been demonstrated that this halide solid electrolyte has higher ionic conductivity than the conventional halide solid electrolytes Li3YCl6, Li3YBr6, and Li3InBr6. This last electrolyte, in particular, has very low ionic conductivity and exhibits a phase transition at 55°C.

[0009] European Patent Application Publication No. 3 965 199 focuses on providing a halide solid electrolyte with high ionic conductivity and improved stability in air and water. From among the many candidates presented, this application concerns the formula Li3Y 1-d In d Cl6, specifically Li3In 0.8 Y 0.2 Cl6 and Li3In 0.2 Y 0.8 This document discloses a solid halide electrolyte of Cl6. However, this document indicates that the degree of crystallinity of the solid halide electrolyte is a factor in improving stability and ionic conductivity. This document does not include any reference to the chemical composition of a specific solid halide electrolyte. [Overview of the project]

Problems to be Solved by the Invention

[0010] The present application aims to provide a novel halide solid electrolyte having high ionic conductivity and improved stability. In particular, the halide solid electrolyte provided herein has lower hygroscopicity than known halide solid electrolytes.

[0011] For this purpose, the halide solid electrolyte of the general formula M3Me 1-x In x Cl 6-y Br y where M contains an alkali metal element and Me is a trivalent element selected from Y, Al, Sc, La, Ce, Gd, Er, and Yb, was investigated.

[0012] However, while solving this technical problem, the inventors surprisingly discovered that only a part of the mixture assumed to lead to this general formula results in a solid solution, i.e., a pure compound.

Means for Solving the Problems

[0013] Thus, according to a first aspect, the present invention relates to a solid electrolyte material of formula (I). M3Me 1-x In x Cl 6-y Br y (I), where M contains an alkali metal element, particularly Li, Me is a trivalent element selected from Y, Al, Sc, La, Ce, Gd, and Er, x is greater than 0 and less than 0.50, y is greater than 1.0 and less than 3.0.

[0014] According to a second aspect, the present invention also relates to a process for producing the solid electrolyte material according to the present invention, which is the following: - Mixing a precursor containing ammonium halide, NH4Cl, NH4Br, one or more Me metal compounds, one or more In metal compounds, and one or more M metal compounds in stoichiometric ratios in a medium selected from aqueous solutions, alcoholic solutions, or other polar molecular solutions. - The resulting mixture is heated at a temperature in the range of 200°C to 800°C, particularly 400°C to 700°C, preferably 500°C to 650°C, for a period of 1 hour to 100 hours, particularly 10 hours to 80 hours, preferably 20 hours to 60 hours. Includes.

[0015] According to a third aspect, the present invention relates to another process for producing a solid electrolyte material according to the present invention, the following: - Mixing a precursor containing ammonium halide, NH4Cl, NH4Br, one or more Me metal compounds, one or more In metal compounds, and one or more M metal compounds in stoichiometric ratios in a medium selected from aqueous solutions, alcoholic solutions, or other polar molecular solutions. - Dry the mixture to obtain the formula (NH4)3M3Me 1-x In x Cl 6-y+3z Br y+3z’ Here, we obtain a solid solution where z+z'=1. - The solid solution is heated at a temperature in the range of 150°C to 800°C, particularly 250°C to 700°C, preferably 300°C to 650°C, for a period of 15 minutes to 12 hours, particularly 30 minutes to 10 hours, preferably 1 hour to 5 hours. Includes.

[0016] According to a fourth aspect, the present invention further relates to a battery, particularly an all-solid-state battery, having a cathode, an anode, and at least one electrolyte layer provided between the cathode and the anode, wherein the cathode, anode, and at least one of the electrolyte layers include a solid electrolyte material according to the present invention.

[0017] Advantages of the present invention

[0018] This invention maximizes the properties of so-called "composite halide" solid electrolytes and halide solid electrolytes incorporating indium.

[0019] In this specification, a "complex halide" solid electrolyte refers to a halide solid electrolyte comprising at least two halide anions, particularly a halide solid electrolyte comprising at least one chloride and at least one bromide. In other words, the chemical formula of the compound of the present invention is X 6-y X' y This includes, where X and X' are two different halide anions selected from fluoride, chloride, bromide, and iodide, in particular, X is chloride and X' is bromide.

[0020] Some composite halide solid electrolytes are known to potentially possess both relatively higher ionic conductivity and relatively better oxidative stability than their single halide solid electrolyte counterparts.

[0021] Furthermore, the inventors surprisingly discovered that introducing indium into a composite halide solid electrolyte makes it possible to improve its stability in water.

[0022] However, the mixing of different elements required to obtain a solid electrolyte results in a crystalline solid solution only under a specific stoichiometry, and this specific stoichiometry constitutes the present invention.

[0023] This invention provides a cost-effective solution and offers a halide solid electrolyte that is relatively easy to implement on an industrial scale because it has high ionic conductivity while also exhibiting improved stability. [Brief explanation of the drawing]

[0024] [Figure 1]Figure 1 shows the X-ray diffraction (XRD) patterns of embodiments according to the present invention, from top to bottom, including: Li3Y0.75In0.25Br2Cl4; Li3Y0.80In0.20Br2Cl4; Li3Y0.85In0.15Br2Cl4; Li3Y0.90In0.10Br2Cl4; and Li3Y0.85In0.15Br2.5Cl3.5. Figure 1 also includes a mark indicating the peak position of Li3YBr6.

[0025] [Figure 2] Figure 2 shows the XRD patterns of comparative examples of synthesis described herein, from top to bottom: Li3Y0.75In0.25BrCl5; Li3Y0.5In0.5BrCl5; Li3Y0.5In0.5Br2Cl4; and Li3Y0.5In0.5Br3Cl3.

[0026] [Figure 3] Figure 3 shows the XRD pattern of Li3Y0.5In0.5Cl6, a reference example of synthesis described herein, where the peak positions corresponding to the crystal structure of Li3InCl6 are superimposed by solid vertical lines. [Modes for carrying out the invention]

[0027] The solid electrolyte material according to the present invention is represented by the following formula (I): M3Me 1-x In x Cl 6-y Br y (I) Here, M, Me, x, and y are as defined herein.

[0028] In certain embodiments, M may include Li, Na, K, Rb, Cs, or any combination thereof. For example, M may include at least one of Li and Na, or a combination thereof. In further embodiments, M may consist of at least one alkali metal element. For example, M may essentially consist of at least one alkali metal element selected from the group consisting of Li, Na, K, Rb, and Cs. In another example, M may consist of Li. In yet another example, M may consist of a combination of Li and at least one of Na, K, Rb, and Cs. In yet another example, M may consist of Na and at least one of Cs and Rb. In yet another example, M may consist of at least one of Na and Cs.

[0029] Preferably, M is Li.

[0030] In certain embodiments, Me is a trivalent rare earth element that can be selected from Y, Sc, Ce, Gd, Er, La, Yb, and combinations thereof. In further examples, Me may be Al.

[0031] Preferably, Me is Y.

[0032] In some embodiments of the present invention, x is in the range of 0.05 to 0.40, particularly 0.07 to 0.35, and preferably 0.10 to 0.30.

[0033] In a preferred embodiment of the present invention, x is in the range of 0.10 to 0.25.

[0034] In another preferred embodiment of the present invention, x is at least 0.015, particularly in the range of 0.015 to 0.50, and preferably in the range of 0.015 to 0.30.

[0035] According to the present invention, x can be 0.1, 0.15, 0.2, or 0.25.

[0036] If x exceeds the upper limit of the range listed above, it is demonstrated herein that a single single-phase and pure compound cannot be obtained with respect to the corresponding formula.

[0037] In some embodiments of the present invention, y is in the range of 1.75 to 3.0, particularly 1.50 to 3.50, and preferably 2.0 to 3.50.

[0038] In a preferred embodiment of the present invention, y is in the range of 2.0 to 2.5.

[0039] According to the present invention, y can be 2 or 2.5.

[0040] If y is smaller than the lower limit of the ranges listed above, it is demonstrated herein that a single, single-phase, and pure compound cannot be obtained with respect to the corresponding formula.

[0041] If y exceeds the upper limit of the range listed above, the electrochemical stability of the resulting compound will not be satisfactory. In particular, since oxidation of the compound begins at a relatively low voltage, a relatively low operating voltage will be required for the battery containing this material.

[0042] In a preferred embodiment of the present invention, the solid electrolyte material of formula (I) is Li3Y 0.75 In 0.25 Cl4Br2, Li3Y 0.8 In 0.2 Cl4Br2, Li3Y 0.85 In 0.15 Cl4Br2, Li3Y 0.9 In 0.1 Cl4Br2, Li3Y 0.85 In 0.15 Cl 3.5 Br 2.5 , and Li3Y 0.985 In 0.015 A selection may be made from the group consisting of Cl4Br2, preferably Li3Y 0.75 In 0.25 Cl4Br2, Li3Y 0.8 In 0.2 Cl4Br2, Li3Y0.85 In 0.15 Cl4Br2, Li3Y 0.9 In 0.1 Cl4Br2 and Li3Y 0.85 In 0.15 Cl 3.5 Br 2.5 You may choose from the group consisting of the following.

[0043] In another preferred embodiment of the present invention, the solid electrolyte material of formula (I) is Li3Y 0.985 In 0.015 It is Cl4Br2.

[0044] Regarding the solid electrolyte material according to the present invention, Cu(K α The X-ray diffraction (XRD) patterns obtained using a radiation source (=1.54060 nm) include at least one peak in each of the following 2θ ranges: [13.7~14.7]; [28.2~29.2]; [32.4~33.4]; [46.9~47.9].

[0045] The parentheses indicate that these ranges include their minimum and maximum values.

[0046] battery

[0047] A battery can be obtained by assembling it using the solid electrolyte material according to the present invention, using techniques well known to those skilled in the art. In particular, such a battery is an all-solid-state battery. Such a battery forms part of the present invention.

[0048] Accordingly, the present invention relates to a battery, particularly an all-solid-state battery, comprising a cathode, an anode, and at least one electrolyte layer provided between the cathode and the anode, wherein at least one of the cathode, anode, and electrolyte layer comprises a solid electrolyte material according to the present invention.

[0049] The above-described battery comprises a cathode, an anode, and at least one electrolyte layer. The electrolyte layer is provided between the cathode and the anode. At least one of the cathode, anode, and electrolyte layer comprises a solid electrolyte material according to the present invention.

[0050] In the battery according to the present invention, the anode may include an anode active material.

[0051] Anode active material is a material that can store and release metal ions, particularly alkali metal ions, such as Li ions or Na ions.

[0052] Metals, carbon, oxides, or nitrides can be used as the anode active material.

[0053] Suitable metals for use as anode active materials can be single metals or alloys, such as lithium metal or lithium alloys. Suitable metals for use as anode active materials can be selected from silicon, tin, silicon compounds, tin compounds, lithium, and lithium alloys.

[0054] Examples of carbon suitable for use as an anode active material include natural graphite, coke, development carbon, carbon fibers, spheroidal carbon, artificial graphite, and amorphous carbon.

[0055] Therefore, the anode active material is the following: - Oxides, - Nitride - Carbon, such as natural graphite, coke, carbon for development, carbon fibers, spheroidal carbon, artificial graphite, and amorphous carbon, - Metals, such as silicon, tin, sodium, or lithium, their compounds and alloys, The anode active material may be selected from among, in particular, silicon, tin, lithium, their compounds and alloys, for example, Li x In y The anode active material is selected from those in the range of 0 to 1 and y in the range of 0 to 1, and preferably Li 0.5 It is In.

[0056] The anode active material may exist in particulate form in the battery according to the present invention. The median diameter of the anode active material particles may be in the range of 0.1 μm to 100 μm. Preferably, the median diameter of the anode active material particles is larger than the median diameter of the sulfide solid electrolyte particles.

[0057] The thickness of the anode in the battery according to the present invention may be in the range of 10 μm to 500 μm.

[0058] In the battery according to the present invention, the cathode may take the form of a cathode composite containing a cathode active material.

[0059] Preferably, the cathode composite contains the solid electrolyte according to the present invention. In particular, the cathode may contain particles comprising the solid electrolyte according to the present invention, and preferably the solid electrolyte according to the present invention.

[0060] Cathode active material is a material that can store and release metal ions, particularly alkali metal ions, such as Li ions or Na ions.

[0061] As cathode active materials, transition metal fluorides, polyanionic materials, fluorinated polyanionic materials, transition metal sulfides, transition metal oxyfluorides, transition metal oxysulfides, transition metal oxynitrides, and lithium-containing transition metal oxides, doped or undoped, coated or uncoated, can be used. In particular, the cathode active material may be a transition metal oxide, such as lithium cobalt oxide, lithium nickel cobalt aluminum oxide, or lithium nickel manganese cobalt oxide, or a transition metal phosphate, such as lithium iron phosphate, lithium cobalt phosphate, lithium nickel phosphate, or lithium manganese phosphate. Suitable transition metal oxides for use as cathode active materials include, for example, LiNi 0.6 Mn 0.2 Co 0.2 It can be O2, Li(NiCoAl)O2, and LiCoO2. Preferably, the cathode active material is LiNi 0.6 Mn0.2 Co 0.2 It is a transition metal oxide with the formula O2. Alternatively, the cathode active material can be LiFePO4.

[0062] The cathode active material may exist in particle form in the battery according to the present invention. The median diameter of the anode active material particles may be in the range of 0.1 μm to 100 μm.

[0063] The thickness of the anode in the ASSB or assembly of the present invention may be in the range of 10 μm to 500 μm.

[0064] In the battery of the present invention, a buffer layer may be deposited on at least one surface of the cathode, anode, or electrolyte layer. The buffer layer may include, and more particularly may consist of, a buffer material selected from the following: lithium phosphate, e.g., Li3PO4, or lithium oxynitride phosphate; lithium nitride; NASICON, e.g., LiTi2(PO4)3; perovskite, e.g., (LaLi)TiO3; LISICON, e.g., Li 14 ZnGe4O 16 , Li4SiO4, or LiGeO4; and garnet, for example Li7La3Zr2O 12 Preferably, the buffer layer contains Li3PO4, and more particularly consists of Li3PO4.

[0065] In the battery according to the present invention, at least one of the anode and cathode may contain an electron conductor compound selected from natural or artificial graphite, graphene, carbon nanotubes, acetylene black, ketogen black, activated carbon, carbon fluoride, metal powder, conductive whiskers, conductive metal oxides, conductive polymers, metal fibers, or carbon fibers, and preferably the electron conductor is a vapor-deposited carbon fiber.

[0066] Generation process

[0067] Generally, the solid electrolyte material according to the present invention can be produced from ordinary precursors according to the prior art, which is well known to those skilled in the art.

[0068] Specifically, the solid electrolyte material according to the present invention can be produced by a dry method or a liquid-phase method.

[0069] In one embodiment, the solid electrolyte material according to the present invention is obtained by a dry method.

[0070] In this embodiment, the precursors are MCl, MBr, InCl3, and MeCl3, where M and Me are as defined above herein, and preferably the precursors are LiCl, LiBr, InCl3, and YCl3.

[0071] The above precursors can be mixed in stoichiometric ratios in powder form.

[0072] The powder mixture may be heated at a temperature in the range of 200°C to 800°C, particularly 400°C to 700°C, preferably 500°C to 650°C, for a period of 1 hour to 100 hours, particularly 10 hours to 80 hours, preferably 20 hours to 60 hours.

[0073] Therefore, the process for producing the solid electrolyte material according to the present invention is as follows: - Mixing precursors, such as MCl, MBr, InCl3, MeCl3, and especially LiCl, LiBr, InCl3, and YCl3, in stoichiometric ratios. - The resulting mixture is heated at a temperature in the range of 200°C to 800°C, particularly in the range of 400°C to 700°C, preferably in the range of 500°C to 650°C, for a period of 1 hour to 100 hours, particularly in the range of 10 hours to 80 hours, preferably in the range of 20 hours to 60 hours. Includes.

[0074] In an alternative embodiment, the solid electrolyte material according to the present invention is obtained by a liquid-phase method.

[0075] According to this embodiment, (NH4)3Me 1-x In x Cl 6-y Bry MCl and MBr are formed from a reaction mixture comprising a medium selected from aqueous solutions, alcoholic solutions, or other polar molecular solutions, and a precursor comprising ammonium halide, NH4Cl, NH4Br, one or more Me metal compounds, one or more In metal compounds, one or more M metal compounds, or any combination thereof, where Me, M, x, and y are as defined herein above.

[0076] Metal compounds can exist in the form of oxides, carbonates, sulfides, sulfates, hydrates, hydroxides, oxalates, acetates, nitrates, or any combination thereof.

[0077] In particular, Me and In metal compounds may include oxides of In2O3 and / or Me2O3, for example, Y2O3.

[0078] In particular, the M metal compound may include carbonates, such as lithium carbonate, sodium carbonate, cesium carbonate, or combinations thereof. Preferably, the M metal compound is lithium carbonate.

[0079] The M metal compound may include halides such as LiCl, LiBr, NaCl, NaBr, CsCl, and CsBr.

[0080] The precursor may further contain an acid, which promotes acidic synthesis in the medium.

[0081] The above precursor is introduced into the medium in stoichiometric ratios.

[0082] In certain embodiments, the reaction mixture may be formed in water and may include NH4Cl;NH4Br;Y2O3;In2O3;lithium carbonate (Li2CO3), and at least one lithium metal compound selected from lithium halides, particularly LiCl and / or LiBr, preferably LiCl; and hydrochloric acid (HCl) and / or hydrobromic acid (HBr).

[0083] The above reaction mixture yields a mixture of reaction products, which, as previously mentioned, are (NH4)3Me 1-x In x Cl 6-y Br y These are MCl and MBr.

[0084] The mixture of the above reaction products may be dried to promote the solid-phase reaction between the reaction products. Drying may be carried out in air or dry air and / or under vacuum or reduced pressure, for example, at 100 mbar, 40 mbar, 1 mbar, or even 0.01 mbar. An N2 stream or an Ar stream may be used to promote the removal of water. Heating may be applied to promote the evaporation of water. The heating temperature may be in the range of 100°C to 160°C. Drying may be carried out until a small amount of moisture, for example, 1% to 3% by weight, remains in the mixture.

[0085] The above reaction products result in the following solid solution: (NH4)3M3Me 1-x In x Cl 6-y+3z Br y+3z’ Here, z+z'=1.

[0086] The solid electrolyte material of the present invention can be obtained by decomposing ammonium halide from a solid solution.

[0087] The solid solution may be heated to a temperature in the range of 150°C to 800°C, particularly 250°C to 700°C, preferably 300°C to 650°C, thereby producing NH4Cl, NH4Br, and / or NH4Cl z Br z’ This enables the sublimation of ammonium halides.

[0088] The heating temperature can be selected based on the composition of the solid solution. For example, in the case of a relatively volatile solid solution, the heating temperature may be relatively low. In another example, the heating temperature may be at least 150°C lower than the melting point and / or up to 50°C higher than the melting point of the solid solution.

[0089] Heating may be carried out in a crucible made of a material inert to the reactants and products. For example, the crucible may be made of quartz, alumina, silica-alumina, BN, glassy carbon, or graphite, such as graphite with a pyrolysis carbon coating. Heating may be carried out in a dry and neutral atmosphere, such as air or dry air. An inert gas, such as N2 or Ar, may be used to accelerate the process. Heating may be carried out for at least 15 minutes to a maximum of 12 hours, particularly 30 minutes to 10 hours, preferably 1 hour to 5 hours.

[0090] The sublimation of the ammonium halide can be monitored by recovering and waiting for the dispersed ammonium halide to complete. In particular, the sublimation may be allowed to complete, thereby essentially eliminating the ammonium halide from the solid electrolyte material of formula (I).

[0091] Finally, cooling can be carried out, for example, in air, dry air, or an N2 atmosphere. This cooling can be carried out at temperatures below 200°C, for example, a maximum of 100°C, particularly a maximum of 70°C, preferably a maximum of 50°C, and even more preferably a maximum of 30°C. Preferably, this cooling can be carried out at room temperature (20-25°C). Optionally, this cooling can be assisted by a flow of Ar or N2. This cooling can be carried out at a cooling rate range of 10-100°C / min.

[0092] Care must be taken to carefully control the amount of oxygen-containing species (e.g., oxides, hydroxides, and / or water) that may be present in the process of forming the solid electrolyte material of the present invention. Excessive oxygen-containing species may cause the formation of impurity phases, which may reduce certain performance characteristics of the battery components formed using the solid electrolyte material, such as ionic conductivity. For example, solid-phase or melting reactions may be carried out in a neutral atmosphere with limited water content or an oxygen level of less than 10 ppm. In further examples, the initial amount of halogenated compounds, such as acids or ammonium halides, may be greater than the stoichiometric amount based on the theoretical chemical equilibrium (e.g., at least 10% more), thereby ensuring the yield of the composite halide material and reducing the level of oxygen-containing phases derived from metal oxide or metal carbonate raw materials to a level undetectable by XRD.

[0093] Therefore, the process for producing the solid electrolyte material according to the present invention is as follows: - Mixing a precursor containing ammonium halide, NH4Cl, NH4Br, one or more Me metal compounds, one or more In metal compounds, and one or more M metal compounds in stoichiometric ratios in a medium selected from aqueous solutions, alcohol solutions, or other polar molecular solutions. - Dry the mixture to obtain the formula (NH4)3M3Me 1-x In x Cl 6-y+3z Br y+3z’ Here, we obtain a solid solution where z+z'=1. - The solid solution is heated at a temperature in the range of 150°C to 800°C, particularly 250°C to 700°C, preferably 300°C to 650°C, for a period of 15 minutes to 12 hours, particularly 30 minutes to 10 hours, preferably 1 hour to 5 hours. Includes. [Examples]

[0094] Synthesis of solid halogen electrolytes

[0095] [Table 1]

[0096] The halide solid electrolytes shown in the last column of Table 1 above were synthesized by weighing the mass of a precursor selected from LiCl, LiBr, InCl3, YCl3, and YBr3 according to the corresponding row in the table.

[0097] For each synthesis, the above precursor was introduced into a mortar and manually ground using a pestle for 15 minutes. Then, the resulting ground powder was placed in a quartz ampoule, and 10 -2 The ampoules were sealed under a high vacuum of mBar. The sealed ampoules were placed in a box-type furnace at 600°C for 30 hours. After this heat treatment, the ampoules were opened in a nitrogen-filled glove box and the resulting halogen solid electrolyte powder was recovered.

[0098] The above powder was sampled for XRD analysis.

[0099] XRD analysis

[0100] XRD analysis was performed using a Bruker D2 Phaser diffractometer to determine Cu(K) α The test was performed using a source (=1.54060nm).

[0101] Li3Y is an example of this. 0.5 In 0.5 Cl6 was synthesized, and its XRD pattern showed that of the pure compound. Comparison with the peak position of Li3InCl6 demonstrates that these compounds are not identical, and consequently, Y is clearly incorporated into the synthesized compound.

[0102] Furthermore, Figure 1 shows the XRD pattern, and the peak positions are similar to those of Li3Ybr6 (C2 / m space group), differing only in the lattice constant. These patterns correspond to the pure compound.

[0103] On the one hand, Figure 2 shows the XRD pattern corresponding to the comparative example. The diffraction pattern was compared with the database without finding a match with a pure phase. Furthermore, the correspondence with the diffraction pattern of a single phase was negated using the two-unit cell search by DICVOL software.

[0104] As a conclusion, as demonstrated by the XRD pattern, the compound of formula (I) according to the present invention could be obtained as a pure compound, whereas the compounds not corresponding to the parameters of this formula became mixtures of different phases and could not be obtained.

[0105] Ionic conductivity

[0106] Approximately 100 mg of the powder was introduced into a polyetherimide (PEI) cylinder with a diameter of 8 mm, and then compressed to a pressure of 4 t·cm -1 between two stainless steel plungers. The pressure was maintained and each piston was connected to the terminals of a potentiostat. The ionic resistance measurement was performed by electrochemical impedance spectroscopy (EIS) at OCV, and an excitation amplitude of 50 mV was applied in the frequency range of 7 MHz to 1 Hz at 15 points per decade using an MTZ impedance analyzer (BioLogic). At the end of the measurement, both pistons were removed and the pressure was reduced to 0. Inside the PEI cylinder, the powder took the form of a dense pellet, and its thickness was measured. Then, the ionic conductivity of the material was calculated using the resistance value, thickness, and surface area of the pellet. The ionic conductivity of the halide solid electrolyte measured in this way is reported in Table 2 below.

[0107]

Table 2

[0108] Thus, the composite halide solid electrolyte according to the present invention exhibits an ionic conductivity 2 times higher compared to a similar electrolyte without indium and 40 times higher compared to a "single halide" solid electrolyte containing only chloride as the halide.

[0109] Hygroscopic

[0110] Approximately 10 grams of electrolyte powder were spread uniformly across the entire surface of a flat plate in a glove box under nitrogen (DP = -80°C) to form a uniform surface with a thickness of 1 millimeter. The plate was then placed on a balance in the glove box at -50°C DP and humidity. The mass of the electrolyte was measured every hour for 10 hours. The mass absorption from t=0 to t=10 hours (10h) was calculated and reported in Table 3 below.

[0111] [Table 3]

[0112] Therefore, the composite halide solid electrolyte according to the present invention has half the hygroscopicity of an equivalent composite halide solid electrolyte that does not contain indium.

Claims

1. A solid electrolyte material of formula (I): M ３ Me １－ｘ In ｘ Cl ６－ｙ Br ｙ (I)、 Here, M contains alkali metal elements, and in particular Li, Me is a trivalent element selected from Y, Al, Sc, La, Ce, Gd, and Er. x is greater than 0 and less than 0.50, y is greater than 1.0 and less than 3.

0. Solid electrolyte material.

2. The solid electrolyte material according to claim 1, wherein M is Li.

3. The solid electrolyte material according to claim 1 or 2, wherein Me is Y.

4. The solid electrolyte material according to any one of claims 1 to 3, wherein x is in the range of 0.05 to 0.40, particularly 0.07 to 0.35, and preferably 0.10 to 0.

30.

5. A solid electrolyte material according to any one of claims 1 to 4, wherein x is in the range of 0.10 to 0.

25.

6. The solid electrolyte material according to any one of claims 1 to 5, wherein y is in the range of 1.75 to 3.0, particularly 1.50 to 3.50, and preferably 2.0 to 3.

50.

7. A solid electrolyte material according to any one of claims 1 to 6, wherein y is in the range of 2.0 to 2.

5.

8. Cu(K α The solid electrolyte material according to any one of claims 1 to 7, wherein the X-ray diffraction (XRD) pattern obtained using a radiation source (= 1.54060 nm) includes at least one peak in each of the following 2θ ranges: [13.7–14.7]; [28.2–29.2]; [32.4–33.4]; [46.9–47.9].

9. where the formula (I) is Li ３ Y ０．７５ In ０．２５ Cl ４ Br ２ 、Li ３ Y ０．８ In ０．２ Cl ４ Br ２ 、Li ３ Y ０．８５ In ０．１５ Cl ４ Br ２ 、Li ３ Y ０．９ In ０．１ Cl ４ Br ２ 、Li ３ Y ０．８５ In ０．１５ Cl ３．５ Br ２．５ 、及びLi ３ Y ０．９８５ In ０．０１５ Cl ４ Br ２ selected from the group consisting of, preferably, Li ３ Y ０．７５ In ０．２５ Cl ４ Br ２ 、Li ３ Y ０．８ In ０．２ Cl ４ Br ２ 、Li ３ Y ０．８５ In ０．１５ Cl ４ Br ２ 、Li ３ Y ０．９ In ０．１ Cl ４ Br ２ 、及びLi ３ Y ０．８５ In ０．１５ Cl ３．５ Br ２．５ The solid electrolyte material according to any one of claims 1 to 8, selected from the group consisting of.

10. A process for producing a solid electrolyte material according to any one of claims 1 to 9, wherein the following: - Precursors, e.g., MCl, MBr, InCl ３ MeCl ３ In particular, LiCl, LiBr, InCl ３ , and YCl ３ To mix them in stoichiometric ratios, - The resulting mixture is heated at a temperature in the range of 200°C to 800°C, particularly 400°C to 700°C, preferably 500°C to 650°C, for a period of 1 hour to 100 hours, particularly 10 hours to 80 hours, preferably 20 hours to 60 hours. The generation process, including the generation process.

11. A process for producing a solid electrolyte material according to any one of claims 1 to 9, wherein the following: - Ammonium halide, NH in a medium selected from aqueous solutions, alcohol solutions, or other polar molecular solutions. ４ Cl, NH ４ Mixing a precursor containing Br, one or more Me metal compounds, one or more In metal compounds, and one or more M metal compounds in stoichiometric ratios. - Dry the mixture to obtain formula (NH ４ ) ３ M ３ Me １－ｘ In ｘ Cl ６－ｙ＋３ｚ Br ｙ＋３ｚ’ Here, we obtain a solid solution where z + z' = 1. - The solid solution is heated at a temperature in the range of 150°C to 800°C, particularly 250°C to 700°C, preferably 300°C to 650°C, for a period of 15 minutes to 12 hours, particularly 30 minutes to 10 hours, preferably 1 hour to 5 hours. The generation process, including the generation process.

12. The medium is water, and the precursor is NH ４ Cl;NH ４ Br;Y ２ O ３ In ２ O ３ Li ２ CO ３ The production process according to claim 11, further comprising: a lithium halide, and at least one lithium metal compound, particularly LiCl and / or LiBr, preferably selected from LiCl; and HCl and / or HBr.

13. A battery, particularly an all-solid-state battery, comprising a cathode, an anode, and at least one electrolyte layer provided between the cathode and the anode, wherein at least one of the cathode, the anode, and the electrolyte layer comprises a solid electrolyte material according to any one of claims 1 to 9.

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