Powder of solid material particles containing at least the elements Li, P and S

Abstract

The present disclosure relates to a powder of solid material particles comprising at least the elements Li, P and S, characterized in that the particle surface has a thiol to carbonate surface group ratio, measured by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) on a Bruker FTIR (MIR) Vertex 70 spectrometer, of less than 2. The present disclosure also relates to a process for preparing such a powder, and to the use of such a powder, in particular for manufacturing a solid electrolyte or battery article.

Description

[Technical field]

[0001] This application claims priority to Nr 21315135.0 filed in Europe on August 2, 2021, the entire contents of which are incorporated herein by reference for all purposes.

[0002] The present disclosure relates to powders of solid material particles comprising at least the elements Li, P and S, characterized in that the particle surface has a thiol to carbonate surface group ratio of less than 2, as measured by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) on a Bruker FTIR (MIR) Vertex 70 spectrometer. The present disclosure also relates to a process for preparing such powders, as well as the use of such powders, in particular for manufacturing solid electrolyte or battery articles. [Background technology]

[0003] Lithium-ion batteries are widely used, especially as power sources for consumer electronics. In such secondary batteries, organic solvents are used as organic liquid electrolytes, and lithium ions migrate from one electrode to the other depending on whether the battery is being charged or discharged.

[0004] Since the solvents used as electrolytes are flammable, all-solid-state lithium-ion batteries that do not use organic solvents are very attractive. Such all-solid-state lithium-ion batteries are formed by solidifying the entire battery, i.e., with all solid components: cathode, anode, and electrolyte. Since all components of an all-solid-state battery, including the electrolyte, are solid, all-solid-state batteries have a higher electrical resistance and a lower output current than batteries using liquid electrolytes. This means that an electrolyte with high electrical conductivity and the ability to maintain this high conductivity over time is required.

[0005] It is known that surface groups determine certain performance parameters of solid electrolyte materials, in particular their electrical conductivity. It is also generally known that material surfaces can be modified when they come into contact with moisture and CO2 present in the atmosphere, which changes the electrical conductivity of the solid interface. For example, sulfur atoms in such materials tend to react with moisture in the air to produce hydrogen sulfide, which is undesirable.

[0006] The object of the present invention is to provide an electrolyte that exhibits high electrical conductivity and resistance to ageing, including the ability to maintain such high electrical conductivity over time, without compromising other important properties such as chemical and mechanical stability, while at the same time minimizing the generation of hydrogen sulfide. Summary of the Invention

[0007] The present invention relates to a powder of solid material particles comprising at least the elements Li, P and S, characterized in that the particle surface has a thiol to carbonate surface group ratio of less than 2, as measured by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) on a Bruker FTIR (MIR) Vertex 70 spectrometer (25° C., atmospheric pressure, argon flow rate of 25 Nml / min).

[0008] In some embodiments, the solid material has Formula (I): Li a P.S. b X c (I) (In the formula, -X represents at least one halogen element; -a represents a number between 2.0 and 7.0, -b is a number between 3.5 and 6.0, -c represents a number between 0 and 3.0.

[0009] In some embodiments, the solid material has formula (II): Li 7-x P.S. 6-x X x (II) (In the formula, -X represents at least one halogen element selected from the group consisting of F, Cl, Br, and I, or a combination thereof; -x represents a positive number between 0.5 and 2.0.

[0010] The solid material is preferably Li6PS5Cl, Li4P2S6, Li7PS6, Li7P3S 11 Or Li3PS4.

[0011] The present invention also relates to a method for making the powder of the present invention, the method comprising the steps of: a) mixing the starting materials, optionally with high energy, to obtain a paste in a slurry state; b) drying the paste from step a); b') optionally pressing the dried paste from step b) into pellets; c) heating the dried paste, for example in the form of pellets, to a temperature of from 350° C. to 580° C. for a period of at least 2 hours, for example 4 hours, 6 hours, 8 hours, 10 hours or 12 hours.

[0012] The present invention also relates to the use of the powder of the present invention for producing a solid electrolyte, a solid electrolyte comprising at least such a powder, an electrochemical device comprising at least such a solid electrolyte, a solid-state battery comprising at least such a solid electrolyte, and an electrode or a battery separator comprising at least such a powder. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] In this application: - any description, even if made in relation to a particular embodiment, is applicable and interchangeable with other embodiments of the invention; - when an element or component is said to be included in and / or selected from a list of enumerated elements or components, in the relevant embodiments expressly contemplated herein, it is to be understood that the element or component may be any one of the individual enumerated elements or components, or may also be selected from the group consisting of any two or more of the explicitly enumerated elements or components, and that any element or component enumerated in a list of elements or components may be omitted from such list; Any recitation herein of numerical ranges by endpoints includes all numbers subsumed within the recited range, as well as the endpoints of the range, and equivalents thereof.

[0014] The present invention relates to a solid electrolyte material having a ratio of thiol surface groups to carbonate surface groups of less than 2.0, as measured by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) on a Bruker FTIR (MIR) Vertex 70 spectrometer (25° C., atmospheric pressure, argon flow rate of 25 Nml / min). The ratio between the considered groups is calculated by taking into account the maximum intensity peaks in the relevant spectral regions, i.e. 2400 cm for thiol groups and 2400 cm for thiol groups. -1 ~2570cm -1 and 1370 cm for carbonate groups. -1 ~1570cm -1 The ratio is calculated by considering the maximum intensity peak in the region of 0.5 to 1.0. The inventors show herein that materials exhibiting such a specific ratio of thiol / carbonate surface groups not only increase the electrical conductivity of the material compared to materials having a thiol to carbonate surface group ratio of more than 2.0, but also exhibit improved resistance to ageing, as measured by its change in electrical conductivity and change in weight over time. Indeed, the inventors show that the ratio to carbonate groups actually provides an improved compromise between the electrical conductivity of the material and its resistance to ageing, thereby making the materials of the invention well suited for use in the manufacture of all-solid-state lithium-ion batteries.

[0015] The powder of solid material particles of the present invention includes at least the elements Li, P and S. In some embodiments, the solid material has the formula (I): Li a P.S. b X c (I) (In the formula, -X represents at least one halogen element; -a represents a number from 2.0 to 7.0, for example, a number from 3.0 to 6.0, 4.0 to 6.0, or 5.0 to 6.0; -b represents a number from 3.5 to 5.0, for example, a number from 3.9 to 5.0 or 4.1 to 5.0; -c represents a number from 0 to 3.0, for example, a number from 0.9 to 2.9 or 1.0 to 2.5).

[0016] According to formula (I), c can be equal to zero. In this case, the solid material does not include any halogen components and the solid material has formula (I'): Li a P.S. b (I') (In the formula, -a represents a number from 2.0 to 7.0, for example, a number from 3.0 to 7.0; -b represents a number from 3.5 to 5.0, for example, a number from 3.9 to 4.9 or 4.0 to 4.5).

[0017] According to formula (I), c can be 0.9 to 1.1. In this case, the solid material has the formula (I″): Li a P.S. b X c’ (I'') (In the formula, -c' represents a number between 0.9 and 1.1, e.g., equal to 1.0).

[0018] According to this formula (I″), X is preferably Cl. In this case, formula (I″) is as follows: Li a P.S. b Cl c’ (I'').

[0019] In some embodiments, the solid material has formula (II): Li 7-x P.S. 6-x X x (II) (In the formula, -X represents at least one halogen element selected from the group consisting of F, Cl, Br, and I, or a combination thereof; -x represents a positive number between 0.5 and 2.0.

[0020] According to these embodiments, -x may more particularly range from 0.8 to 1.8, for example x may be equal to 1.0 or 1.5, x may range from 0.95 to 1.05, or from 1.45 to 1.55, and / or -X is more specifically Cl, Br, or a combination thereof, and X can also be more specifically Cl.

[0021] In some preferred embodiments, the solid material is Li6PS5Cl, Li4P2S6, Li7PS6, Li7P3S 11 or Li3PS4, more preferably Li6PS5Cl or Li3PS4.

[0022] The composition of the solid materials described in this disclosure may be determined according to well-known analytical techniques.

[0023] In the present invention, the solid material characterized by the formula, here formula (I) or (II), may be the main component of the powder, the proportion of which may be at least 60% by weight, at least 70% by weight, at least 80% by weight, at least 90% by weight, at least 95% by weight, or even at least 98% or 99% by weight, based on the total weight of the powder.

[0024] The powders may also include, for example, an amorphous phase, and the starting materials used to prepare the powders, such as LiX (wherein X is a halogen, such as Cl), Li2S, phosphorus sulfide (eg, P2S5), and / or Li3PO4.

[0025] The powder can be characterized by its size or particle size distribution (PSD). The size of the particles of the powder is measured by laser diffraction in paraxylene. - d less than 50 μm, for example less than 40 μm, less than 30 μm, or less than 20 μm 50 -value, -d of more than 0.05μm 10 Value, and / or - d less than 100 μm, for example less than 90 μm, less than 80 μm, or less than 70 μm 90 -value may be indicated.

[0026] The powder may be composed of agglomerated particles.

[0027] d 50 -value corresponds to the median of the distribution of particle diameter values. Measurements of particle size distribution (PSD), e.g. d 50 -value, d 10 -value, and d 90 The -value can be carried out on a number of particles, at least 150, using a scanning electron microscope (SEM), or by laser diffraction in paraxylene.

[0028] The particles of the powder may be spherical in shape.

[0029] The particles of the powder may exhibit a circularity SR of 0.8 to 1.0, more specifically 0.85 to 1.0, even more specifically 0.90 to 1.0. SR may preferably be 0.90 to 1.0 or 0.95 to 1.0. The circularity of a particle is calculated from the measured circumference P and projected area A of the particle using the following formula: SR=4πA / P 2 .

[0030] For an ideal sphere, SR is 1.0, and for spherical particles it is less than 1.0. SR can be determined by dynamic image analysis (DIA). Examples of devices that can be used to perform DIA are Retsch's CAMSIZER® P4 or Sympatec's QicPic®. Circularity can be measured more specifically according to ISO 13322-2 (2006). DIA generally requires the analysis of a statistically meaningful large number of particles (e.g., at least 500 or even at least 1000).

[0031] The powders of the invention are also characterized by a low release of H2S under given conditions. This characteristic can be measured by exposing the powder to a moist atmosphere and measuring the amount of H2S released during the first 50 minutes that the powder is in contact with said atmosphere. For example, when the powder of the invention is exposed for 50 minutes to an atmosphere consisting of moist air with a relative humidity of 35%, the release of H2S can preferably be less than 70 mL / g, the measurement being carried out at a temperature of 23°C. Under the same experimental conditions, it is also possible to determine the release rate of H2S in mLH2S / g / h. This rate can, for example, be lower than 84 mLH2S / g / h for the powders of the invention.

[0032] The crystalline phase of the powder (corresponding to a cubic structure belonging to the space group F-43m) can be characterized by X-ray diffraction (XRD) using a Cu radiation source.

[0033] The powder may advantageously exhibit an ionic conductivity of at least 1.5 mS / cm, such as at least 1.7 mS / cm, or from 1.9 to 5.0 mS / cm, such as from 2.0 to 4.5 mS / cm, measured in a compressed (500 MPa) pellet by impedance spectroscopy at 25° C.

[0034] The measurement of ionic conductivity is carried out on pressed pellets. Typically, pressed pellets are produced using uniaxial or isostatic pressure. When applying uniaxial pressure to form pellets, a pressure of more than 100 MPa, advantageously more than 300 MPa, is applied for a time of at least 30 seconds. Measurements are typically carried out under uniaxial pressure of 2 MPa to 200 MPa.

[0035] The powders of the invention can also be characterized by their resistance to aging, as measured in particular by the change in conductivity and weight over time.

[0036] The change in electrical conductivity of the powders of the present invention, measured according to the following formula (1), is preferably less than 50%:

number

[0037] Preferably, the change in electrical conductivity of the powder is less than 45% or less than 40%, measured according to equation (1).

[0038] The powder of the present invention preferably has a weight change of less than 5% as measured according to the following formula (2):

number

[0039] Preferably, the powder has a weight change of less than 4% or less than 3% as measured according to formula (2).

[0040] The present invention also provides a) mixing the starting materials, optionally with high energy, to obtain a paste in a slurry state; b) drying the paste from step a); b') optionally pressing the dried paste from step b) into pellets; c) heating the dried paste, e.g. in the form of pellets, at a temperature between 350°C and 580°C for a period of at least 2 hours, e.g. 4 hours, 6 hours, 8 hours, 10 hours or 12 hours.

[0041] In some embodiments, the starting materials for step a) are at least lithium sulfide (LiS) and phosphorus sulfide.

[0042] In step a), the starting materials, such as Li2S, LiCl and P2S5, are mixed together. These starting materials are generally in powder form to obtain a homogeneous mixture. The amounts of these starting materials are defined to obtain the targeted stoichiometric ratio. A small excess of Li2S can be used, especially to compensate for possible S losses during calcination. The excess Li2S can be added, for example, up to 10% by weight relative to the targeted stoichiometric ratio.

[0043] Step a) is conveniently carried out by wet ball milling the starting material in a liquid hydrocarbon. The liquid hydrocarbon is preferably selected from the group consisting of ketones, aliphatic hydrocarbons, cycloaliphatic hydrocarbons, aromatic hydrocarbons and mixtures thereof. The aliphatic hydrocarbon is, for example, hexane, heptane, octane or nonane. The cycloaliphatic hydrocarbon is, for example, cyclohexane, cyclopentane or cycloheptane. The aromatic hydrocarbon is, for example, benzene, toluene, ethylbenzene, xylene or liquid naphthenes. A convenient liquid hydrocarbon that can be used is xylene or paraxylene.

[0044] The weight ratio of the hydrocarbon / mixture may be from 0.2 to 3.0, for example from 0.4 to 2.0 or from 0.5 to 1.5.

[0045] The duration of the milling may be from 1 to 130 hours, for example, preferably from 3 to 70 hours or from 6 to 40 hours.

[0046] According to step b), the paste from step a) is dried. Drying can be conveniently carried out by evaporation of the liquid hydrocarbon. The evaporation of the liquid hydrocarbon is preferably carried out at a temperature between 100° C. and 150° C., more particularly between 105° C. and 135° C. The evaporation can be carried out under vacuum. The duration of the evaporation is generally between 1 and 20 hours, more particularly between 2 and 20 hours or between 3 and 7 hours.

[0047] At the end of the evaporation, the mixture may contain some residual hydrocarbons. The amount of residual hydrocarbons is generally such that the C content in the mixture is less than 5.0 wt. %. The C content may be between 0.01 and 3.0 wt. %.

[0048] In step c), the mixture of step b) is heated (or calcined), for example in a rotary oven, at a temperature of 350°C to 580°C, for example 370°C to 550°C, or 390°C to 530°C. Step c) is preferably carried out under an inert atmosphere, for example under an atmosphere of N2 or Ar or H2S. The duration of step c) is 1 to 12 hours, more specifically 2 to 10 hours, or 3 to 7 hours. During step c), the crystallinity of the mixture is improved, which results in an improved electrical conductivity.

[0049] The rotary oven that can be used to sinter the dried paste from step b) or the pellets from step b') can rotate at a rotation speed of 0.5 to 10.0 rpm. The size of the granules can be varied by varying the speed. The higher the rotation speed, the larger the size of the particles. This also means that the higher the rotation speed, the higher the yield of the composition exhibiting the target size.

[0050] The process may include an additional step d) of sieving the granules to select a particular size range. This operation can be performed manually or automatically. In laboratory conditions, it is advantageously performed manually.

[0051] The present invention also relates to various end uses of the powders described herein.

[0052] The powders of the present invention can be used to prepare solid electrolytes.

[0053] The present invention also provides a solid electrolyte comprising at least the powder described herein, an electrochemical device comprising at least a solid electrolyte as described herein, a solid-state battery comprising at least the solid electrolyte described herein, -at least, A metal substrate, at least one layer directly adhered to said metal substrate, (i) a powder of the present invention; (ii) at least one electroactive compound (EAC); (iii) optionally at least one lithium ion conducting material (LiCM) other than the solid-state material of the present invention; (iv) optionally, at least one electrically conductive material (ECM); (v) optionally a lithium salt (LIS); (vi) optionally, at least one layer made from a composition comprising at least one polymeric binder material (P); and -at least, a powder according to the invention, optionally at least one polymeric binding material (P), optionally at least one metal salt, in particular a lithium salt, - optionally a separator comprising at least one plasticizer.

[0054] To the extent that the disclosures of any patents, patent applications, and publications incorporated herein by reference conflict with the statements of this application to the extent that a term may be unclear, this statement shall control. EXAMPLES

[0055] The present disclosure will now be described in more detail with reference to the following examples, the purpose of which is merely illustrative and is not intended to limit the scope of the present disclosure.

[0056] material Inventive Material #1 The material of the present invention, Li6PS5Cl, can be obtained by the following process.

[0057] In the first step, 22.7 g LiCl (Sigma-Aldrich, purity >99%), 59.5 g P2S5 (Sigma-Aldrich, 20 purity >99%) and 61.5 g Li2S are added to a zirconia jar equipped with ZrO2 balls (10 mm). Then, 130 g paraxylene (Sigma-Aldrich, purity >99%, dry) is added. The jar is quickly sealed to prevent evaporation of any solvent. Wet ball milling is performed using a planetary ball mill. After 7 hours of milling at 200 rpm, a paste is obtained.

[0058] In a second step, the paste is transferred into a dry alumina crucible and dried in an oven under dynamic vacuum at 130° C. to remove the solvent. After 5 hours of drying, the mill grinding balls are separated from the dry powder through a 4 mm sieve.

[0059] In the third step, the dried mixture is placed in an alumina reactor under dry air (less than 300 ppm water).The reactor is then placed in a rotary kiln and the product is crystallized at 480°C for 5 hours under N2 flow (20L / h) with a rotation of 1 rpm.The reactor is then cooled without rotation.

[0060] The final product is in the form of a polydisperse powder with several agglomerates of different sizes. The finished product is obtained by dry homogenization.

[0061] Comparison Material #2 The comparative material Li6PS5Cl is obtained by the following process, inspired by the procedure disclosed in Angewandte Chemie, International Edition, 2019, 58, 8681-8686.

[0062] In the first step, 0.631 g of LiCl (Sigma-Aldrich, purity >99%), 1.713 g of P2S5 (Sigma-Aldrich, 20 purity >99%) and 1.713 g of Li2S were added to a 45 ml zirconia bottle equipped with ZrO2 balls. Ball milling is performed using a planetary ball mill. After milling at 500 rpm for 2 hours, a powder is obtained.

[0063] In a second step, the powder is homogenized in a mortar in an Ar-filled glove box (<1 ppm H20, <1 ppm O2) and then pelletized at 500 MPa to produce 6 mm diameter pellets with masses ranging from 300 to 500 mg. These pellets are sealed under vacuum in a carbon-lined quartz tube. The product is crystallized at 550 °C for 7 h with a heating rate of 0.5 °C / min and then cooled to room temperature.

[0064] The final product is in the form of dense pellets, which are obtained by dry homogenization using a mortar in an Ar-filled glove box.

[0065] Test Method PSD Dispersions are prepared for PSD measurements by laser diffraction as follows: 150 mg of powder are placed in 50 mL of paraxylene and stirred for at least 5 minutes. The solution is filtered through an 800 μm sieve and introduced into a Malvern Mastersizer 3000. The data are processed with the Fraunhofer optical model.

[0066] In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) studies were carried out on a Bruker FTIR (MIR) Vertex 70 spectrometer. Measurements were performed using a high temperature reactor chamber and a Praying Mantis diffuse reflectance accessory (Harrick). The reactor chamber is equipped with a KBr window and is measured with a type K thermocouple, which measures the temperature close to the powder. The different gases can be aliquoted by mass flow controllers (Bronkhorst). Measurements were carried out at 25°C and atmospheric pressure under an argon flow rate of 25 Nml / min, which was used to inert the analysis chamber and protect the samples from external moisture. All spectra were taken with an acquisition time of 1 min and a 2 cm -1 A total of 250 scans were recorded, with average values ​​ranging from 600 to 6000 cm. -1 The ratio between the studied groups was determined in the relevant spectral region, i.e., 2400 cm for the thiol group. -1 ~2570cm -1 and the carbonate group at 1370 cm -1 ~1570cm -1 The intensity was calculated by taking the maximum intensity peak of the region at

[0067] Conductivity and electrochemical impedance spectroscopy (EIS) Prior to impedance spectroscopy measurements, the powder samples were cold pressed at 500 MPa in an Ar-filled glove box. Electrical conductivity was acquired on pellets made using a uniaxial press operating at 500 MPa. Pelletization was performed using a laboratory-scale uniaxial press in a glove box filled with moisture-free argon atmosphere. Two carbon paper foils (Papyex soft graphite N998 Ref: 496300120050000 from Mersen, thickness 0.2 mm) were used as current collectors. The pellets with their carbon electrodes attached are then packed in an airtight sample holder and a pressure of 40 MPa is applied on the sample holder for the measurements. Impedance spectra are acquired on a Biologic VMP3 device. Impedance measurements were performed at a stable temperature of about 24 °C. Impedance spectroscopy is acquired in PEIS mode with an amplitude of 20 mV and a frequency range of 1 MHz to 1 kHz (25 points per decade, average of 50 measurements per frequency point).

[0068] Aging resistance The ageing resistance is measured after exposing the material in a dry room for 430 hours. More precisely, both the change in electrical conductivity and the change in weight of the material are measured. Approximately 2 grams of powder is spread in an aluminum cup and exposed to a dry atmosphere with a dew point (DP) of -45°C to -50°C. A second empty aluminum cup is placed next to it as a control. The bands monitored are the thiol groups (-HS) and carbonate groups (CO3 2- ) about 2482cm -1 and 1445cm -1 Corresponds to.

[0069] The mass evolution is monitored over time to assess the amount of impurities (mainly carbonate and water) that may adsorb onto the product surface.

[0070] The change in conductivity (i.e., loss) is measured according to the following equation (1):

number

[0071] The change in weight (i.e., the increase) is measured according to the following formula (2):

number

[0072] result PSD results Inventive Material #1 [ka] d 10 - Value = 9.4μm d 50 - Value = 29.3 μm d 90 - Value = 65.6 μm

[0073] Comparison Material #2 d 10 - Value = 6.8μm d 50 - Value = 26.7 μm d 90 - Value = 103.0 μm

[0074] [Table 1]

[0075] [Table 2]

[0076] [Table 3]

[0077] The results summarized in Tables 1 and 2 show that material #1 of the present invention is less susceptible to the effects of aging than comparative material #2, which exhibits a greater decrease in conductivity with aging, with a ΔC of -73.0% after 430 hours, and material #1 of the present invention achieving a ΔC of only -30.0%.

Claims

1. 2400 cm －１ to 2570 cm －１ the maximum intensity peak in the region of, and 1370 cm －１ to 1570 cm －１ By taking into account the maximum intensity peak in the region of, a powder of solid material particles containing at least Li, P and S elements, characterized in that the thiol to carbonate surface group ratio on the particle surface is less than 2, measured by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) in a Bruker FTIR (MIR) Vertex 70 spectrometer (25 °C, atmospheric pressure, argon flow rate of 25 Nml / min).

2. The solid material is of formula (I): Li ａ PS ｂ X ｃ (I) (wherein, -X represents at least one halogen element, -a represents a number from 2.0 to 7.0, -b represents a number from 3.5 to 6.0, -c represents a number from 0 to 3.0) of the powder according to Claim 1.

3. The solid material is of formula (II): Li ７－ｘ PS ６－ｘ X ｘ (II) (wherein, -X represents at least one halogen element selected from the group consisting of F, Cl, Br and I or a combination thereof, -x represents a positive number from 0.5 to 2.0) of the powder according to Claim 1.

4. The solid material is Li ６ PS ５ Cl, Li ４ P ２ S ６ 、Li ７ PS ６ 、Li ７ P ３ S １１ Or Li ３ PS ４ The powder according to claim 1

5. The powder according to Claim 1, measured by laser diffraction in p-xylene. d less than -50 μm ５０ value d exceeding -0.05 μm １０ value, and / or d less than -100 μm ９０ indicating a value of

6. The powder according to Claim 1, showing an ionic conductivity of at least 1.5 mS / cm, measured in a compressed (500 MPa) pellet by impedance spectroscopy at 25 °C.

7. - The change in its conductivity is given by the following formula (1): (wherein, 【Number 1】 ·ΔC refers to the change in the conductivity of the material after exposure in a drying chamber for 430 hours at 20 °C (dew point < -35 °C), measured by impedance spectroscopy at 25 °C - The change in its weight is given by the following formula (2): ・C ｔ１ refers to the conductivity measured at time t1, i.e., the time after exposing the material at 20 °C in a drying chamber for 430 hours ・C ｔ０ is less than 50% as measured according to (wherein C indicates the initial conductivity of the material measured at time t0), and (wherein, 【Number 2】 ·ΔW refers to the change in the weight of the material after exposure in a drying chamber for 430 hours at 20 °C

8. ・W ｔ１ refers to the weight measured at time t1, i.e., the time after exposing the material to the drying chamber at 20°C for 430 hours ・W ｔ０ is less than 5% as measured according to (wherein W indicates the initial weight of the material measured at time t0), showing weather resistance, the powder according to claim 1. A method for producing the powder according to any one of Claims 1 to 7, comprising: a) mixing the starting materials, optionally using high energy, to obtain a slurry-like paste; b) drying the paste from step a); b') optionally, pressing the dried paste from step b) into pellets; c) heating the dried paste, for example in the form of pellets, to a temperature from 350 °C to 580 °C for a period of at least 2 hours, for example 4 hours, 6 hours, 8 hours, 10 hours or 12 hours.

9. The starting material for step a) is at least lithium sulfide (Li ２ 2S) and phosphorus sulfide, the method according to claim 8.

10. Use of the powder according to any one of Claims 1 to 7 for producing a solid electrolyte.

11. A solid electrolyte comprising at least the powder according to any one of Claims 1 to 7.

12. An electrochemical device comprising at least the solid electrolyte according to Claim 11.

13. A solid-state battery comprising at least the solid electrolyte according to Claim 11.

14. At least, - a metal substrate, - at least one layer directly adhered to the metal substrate, comprising (i) the powder according to any one of Claims 1 to 7, (ii) at least one electroactive compound (EAC), (iii) optionally, at least one lithium ion conductive material (LiCM) other than the solid material of the present invention, (iv) optionally, at least one electrically conductive material (ECM), (v) optionally, a lithium salt (LIS), (vi) optionally, at least one polymer binding material (P), and at least one layer made from a composition containing the same, an electrode. [

15. ] At least, - the powder according to any one of claims 1 to 7, - optionally, at least one polymer binding material (P), - optionally, at least one metal salt, particularly a lithium salt, - optionally, at least one plasticizer, a separator.

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