Lithium-deficient halide-rich solid electrolyte substituted with trivalent elements

Abstract

The present invention relates to a lithium-deficient halide-rich solid electrolyte substituted with aluminum. The inventors have surprisingly discovered that such an aluminum-substituted lithium-deficient halide-rich solid electrolyte exhibits increased ionic conductivity and reduced H2S gas generation upon contact with moisture.

Description

Technology Field

[0001] The present invention relates to a lithium-deficient halide-rich solid electrolyte substituted with a trivalent element, a method for manufacturing the solid electrolyte, and a battery comprising the solid electrolyte. Background Technology

[0002] With the rapid development of small and lightweight electronic products, electronic devices, and communication devices, and the widespread emergence of demand for electric vehicles due to environmental issues, there is a need to improve the performance of secondary batteries used as power sources for these products. Among them, lithium secondary batteries are attracting attention as high-performance batteries due to their high energy density and high reference electrode potential.

[0003] However, the electrolytes typically used in lithium-ion batteries are liquid electrolytes, such as organic solvents. Consequently, safety issues such as electrolyte leakage and fire hazards can occur continuously.

[0004] Recently, all-solid-state batteries containing solid electrolytes instead of liquid electrolytes have been used to improve the safety characteristics of lithium-ion batteries and are receiving significant attention. For example, solid electrolytes are typically safer than liquid electrolytes due to their non-flammable or flame-retardant properties.

[0005] Solid electrolytes may include oxide-based solid electrolytes, polymer-based electrolytes, and sulfide-based electrolytes. Sulfide-based electrolytes have been widely used because they have a wider range of lithium ion conductivity compared to oxide-based and polymer-based solid electrolytes, and an example is a sulfide-based solid electrolyte having an azirodite-type crystal structure.

[0006] Zhang etc. (Journal of Power Sources Volume 450, 29 February 2020, 227601) has the chemical formula Li 6-3x Al xDisclosed is an aluminum-substituted lithium azirodite having PS5Br (0 < x < 0.4).

[0007] Gao etc. (Sci. China Technol. Sci. 66, 2059-2068 (2023)) has the chemical formula Li 6-3x Al x Disclosed is an aluminum-substituted lithium azirodite having PS5I (0 ≤ x ≤ 0.1).

[0008] Ramos etc. (ACS Appl. Mater. Interfaces 2022, 14, 51, 56767-56779) has the chemical formula Li 3+2x P 1-x Al x The synthesis of lithium-deficient halide-rich solid electrolytes having S4 (x = 0.15, 0.20, and 0.33) is described.

[0009] However, there remains a need to provide sulfide-based electrolytes that have high ionic conductivity and reduce H2S gas generation upon contact with moisture.

[0010] The object of the present invention is to provide a lithium-deficient halide-rich solid electrolyte substituted with a trivalent element.

[0011] Another objective of the present invention is to provide a method for manufacturing the solid electrolyte.

[0012] Another objective of the present invention is to provide a battery comprising the solid electrolyte.

[0013] In a first embodiment, the object of the present invention is achieved by providing a solid electrolyte having a composition according to formula (I):

[0014] Li 6-b-3a M 1 a PS 5-b YZ b (I)

[0015] [In the equation, 0 < a < 0.1 and 0 < b < 1.0, and M 1 [Y is a trivalent element, Y is selected from the group consisting of F, Cl, Br, and I, Z is selected from the group consisting of F, Cl, Br, and I, and Y and Z are not the same halogen].

[0016] As demonstrated in the attached examples, the inventors have surprisingly discovered that lithium-deficient halide-rich solid electrolytes substituted with these trivalent elements exhibit increased ionic conductivity. Furthermore, these solid electrolyte compositions according to the present invention exhibit reduced H2S gas generation upon contact with moisture, making them more attractive as solid electrolytes for commercial production and use in batteries.

[0017] Although I do not wish to be bound by a specific theory, these lithium sulfide-based solid electrolytes having an azyrodite structure, such as Li6PS5Cl, exhibit high lithium cation mobility. The addition of trivalent metals, such as aluminum, can replace lithium cations at lithium cation sites within the azyrodite crystal structure, and ideally, each aluminum cation will coordinate with one sulfide anion, thereby suppressing H2S formation. On the other hand, the presence of halogen sites indicates significant disorder, which enables trivalent metal atoms, such as aluminum, to coordinate with more than one sulfide anion center. Furthermore, the fact that these solid electrolyte compositions according to the present invention exhibit reduced H2S gas generation upon contact with moisture is an important safety feature that makes them even more attractive for commercial production and use in batteries.

[0018] In a further embodiment, the present invention provides a method for manufacturing the solid electrolyte.

[0019] In a further embodiment, the present invention provides a battery comprising a solid electrolyte according to the present invention. Brief explanation of the drawing

[0020] Fig. 1a: Li recorded at 298 K in a beryllium-capped closed cell 5.4-3x Al x PS 4.4 BrCl 0.6 Cu K (where x = 0, 0.025, 0.05, 0.075, and 0.1) α X-ray diffraction pattern using radiation. Fig. 1b: Li at 2θ = 43° to 48° 5.4-3x Al x PS 4.4 BrCl 0.6 Enlarged area of ​​the XRD pattern (where x = 0, 0.025, 0.05, 0.075, and 0.1). Fig. 2: Li 5.4-3x Al x PS 4.4 BrCl 0.6 Lattice constant as a function of x for (where x = 0, 0.025, 0.05, and 0.075) a Change of. Fig. 3: Li 5.4-3x Al x PS 4.4 BrCl 0.6 Raman spectra of (x = 0, 0.025, 0.05, 0.075, and 0.1). Fig. 4: 1 liter of air and Li 5.4-3x Al x PS 4.4 BrCl 0.6 H2S produced per 1 mole of (nominal x = 0, 0.025, 0.05, and 0.075). Fig. 5a: Li 5.4 PS 4.4 BrCl 0.6 Voltage profile of a symmetric cell. Fig. 5b: Li 5.25 Al 0.05 PS 4.4 BrCl 0.6 Voltage profile of a symmetric cell. Specific details for implementing the invention

[0021] In the drawings and the following detailed description, preferred embodiments are described in detail to enable the practice of the present invention. While the present invention is described with reference to these specific preferred embodiments, it will be understood that the present invention is not limited to these preferred embodiments. Rather, as will become apparent from the following detailed description and a review of the accompanying drawings, the present invention includes a number of alternatives, modifications, and equivalents.

[0022] The term “comprising,” as used in this application and the claims, should not be interpreted as being limited to the means subsequently listed; it does not exclude other elements or steps. It should be interpreted as specifying the presence of the mentioned features, integers, steps, or components, but does not exclude the presence or addition of one or more other features, integers, steps, or components, or groups thereof. Accordingly, the scope of the expression “composition comprising components A and B” should not be limited to a composition consisting only of components A and B. This means that, in relation to the present invention, the relevant components of the composition are only A and B. Accordingly, the term “comprising” encompasses the more restrictive terms “consisting essentially of” and “consisting of”.

[0023] The term “all-solid-state battery” as used herein refers to a cell or battery comprising only solid or substantially solid components, such as solid electrodes (e.g., anode and cathode) and a solid electrolyte.

[0024] The term “azirodite-type crystal structure” as used herein refers to a crystal structure or crystal system having a crystal structure or crystal system similar to naturally occurring Ag8GeS6 and Li7PS6 (azirodite). An azirodite-type crystal structure may be orthorhombic symmetric, but is more likely cubic symmetric and can be described by the F-43m space group. In some embodiments, an azirodite-type crystal structure may be empirically determined by X-ray diffraction by observing diffraction peaks near 2θ = 15.5±1°, 18±1°, 26±1°, 30.5±1°, and 32±1° using CuKα-line wavelengths, for example.

[0025] X-ray diffraction (XRD) as referred to herein refers to an XRD experiment performed using a Bruker D8 diffractometer equipped with Cu(Kα1-Kα2) or Mo(Kα1-Kα2) radiation in a θ-θ configuration. Preferably, an airtight sample holder capped with a Be window (mostly transparent to X-rays) is used. Preferably, patterns were collected with a step size of 0.02° at 2θ = 10° to 50°.

[0026] Raman spectroscopy as defined herein refers to Raman experiments performed using a Raman DXR Microscope (Thermo Fischer Scientific) equipped with a green laser having an excitation wavelength of 532 nm. Preferably, a laser power of 0.1 mW was used to prevent sample damage due to excessive local heating. Preferably, spectra were collected with an exposure time of 1 second and 180 exposures.

[0027] Ionic conductivity as referred to herein refers to ionic conductivity determined at 25°C unless otherwise noted. This was preferably determined for a cold-pressed sample in a 10 mm die at 625 MPa using a BioLogic CESH cell, and the spectrum was recorded using an MTZ 35 frequency response analyzer by applying a 50 mV AC perturbation in the frequency range of 30 MHz to 1 Hz. Preferably, the relative density of the pellet was 85 to 87% and the thickness was approximately 1.4 mm. Preferably, an indium foil was pressed onto the surface of the pellet as an ion-blocking electrode. More preferably, spectra were collected at 10°C intervals between temperatures ranging from -20 to 50°C using an ITS temperature controller.

[0028] Moisture stability as referred to herein refers to measuring the amount of H2S recorded in ppm units every 20 seconds for 20 minutes using an H2S sensor (model-INS-H2S-03) (0 to 400 ppm, 20 to 90%RH). Preferably, approximately 30 mg of powder was pelletized in a 10 mm die, the pellets were placed on a rectangular polymer container inside a desiccator, and the lid of the desiccator was closed. The temperature during measurement was 22°C, and the relative humidity was 29 to 30%. The number of moles of H2S generated per liter of ambient air and per gram of sample was calculated using the following formula:

[0029]

[0030] In the context of the present invention, liquids will be considered organic or aqueous compounds that are liquids under standard conditions for temperature and pressure as defined by IUPAC. Accordingly, the boiling point and melting point are at standard atmospheric pressure, in other wordsThe boiling point and melting point will be considered to be 101325 Pa. As is understood by those skilled in the art, the presence of organic liquids can be determined through thermogravimetric analysis (TGA) or nuclear magnetic resonance (NMR) spectroscopy, and the presence of aqueous liquids can be determined through Karl Fischer titration.

[0031] The term “solid electrolyte mixture” as used herein refers to an electrolyte mixture that essentially does not contain any liquid. The term “essentially not containing liquid” means that the solid electrolyte mixture contains liquid in an amount of less than 10 wt.% based on the total weight of the solid electrolyte mixture, preferably less than 7.5 wt.%, more preferably less than 5 wt.%, even more preferably less than 2.5 wt.%, and most preferably less than 1 wt.% based on the total weight of the solid electrolyte mixture. In a more preferred embodiment, the solid electrolyte mixture contains liquid in an amount of less than 1000 ppm based on the total weight of the solid electrolyte mixture, preferably less than 500 ppm based on the total weight of the solid electrolyte mixture, more preferably less than 100 ppm based on the total weight of the solid electrolyte mixture, even more preferably less than 50 ppm based on the total weight of the solid electrolyte mixture, and most preferably less than 10 ppm based on the total weight of the solid electrolyte mixture.

[0032] The term “solid electrolyte” as used herein refers to an electrolyte that essentially does not contain any liquid. The term “essentially not containing liquid” means that the solid electrolyte contains liquid in an amount of less than 10 wt.% based on the total weight of the solid electrolyte, preferably less than 7.5 wt.%, more preferably less than 5 wt.%, even more preferably less than 2.5 wt.%, and most preferably less than 1 wt.% based on the total weight of the solid electrolyte. In a more preferred embodiment, the solid electrolyte contains liquid in an amount of less than 1000 ppm based on the total weight of the solid electrolyte, preferably less than 500 ppm based on the total weight of the solid electrolyte, more preferably less than 100 ppm based on the total weight of the solid electrolyte, even more preferably less than 50 ppm based on the total weight of the solid electrolyte, and most preferably less than 10 ppm based on the total weight of the solid electrolyte.

[0033] solid electrolyte

[0034] In a first embodiment, the present invention provides a solid electrolyte having a composition according to formula (I):

[0035] Li 6-b- 3aM1aPS5 -b YZ b (I)

[0036] [In the equation, 0 < a < 0.1 and,

[0037] 0 < b < 1.0, and

[0038] M 1 is selected from the group consisting of B, Al, Y, Sc, Ga, In, and combinations thereof, and

[0039] Y is selected from the group consisting of F, Cl, Br, and I, and

[0040] Z is selected from the group consisting of F, Cl, Br, and I, and

[0041] Y and Z are not the same halogen.

[0042] In a preferred embodiment, the solid electrolyte is according to the present invention and is 0.01 ≤ a < 0.1, preferably 0.02 ≤ a ≤ 0.09, and more preferably 0.025 ≤ a ≤ 0.075. In a specific preferred embodiment, the solid electrolyte is according to the present invention and is 0.01 ≤ a ≤ 0.085, preferably 0.025 ≤ a ≤ 0.08, and more preferably 0.050 ≤ a ≤ 0.75. In a specific preferred embodiment, the solid electrolyte is according to the present invention and is 0.015 ≤ a ≤ 0.035, preferably 0.02 ≤ a ≤ 0.03, and more preferably about 0.025. In a specific preferred embodiment, the solid electrolyte is according to the present invention and is 0.04 ≤ a ≤ 0.06, preferably 0.045 ≤ a ≤ 0.055, and more preferably about 0.05. In a specific preferred embodiment, the solid electrolyte is according to the present invention and is 0.065 ≤ a ≤ 0.085, preferably 0.07 ≤ a ≤ 0.08, and more preferably about 0.075.

[0043] In a preferred embodiment, the solid electrolyte is according to the present invention, and 0.1 ≤ b < 0.9, preferably 0.3 ≤ b ≤ 0.8, and more preferably 0.4 ≤ b ≤ 0.7. In a specific preferred embodiment, the solid electrolyte is according to the present invention, and 0.5 ≤ b ≤ 0.6, preferably b is about 0.6.

[0044] In a preferred embodiment, the solid electrolyte is according to the present invention, and M 1 is selected from the group consisting of B, Al, Y, Sc, Ga, and In, preferably from the group consisting of B, Al, Ga, and In, and most preferably M 1 It is Al.

[0045] In a preferred embodiment, the solid electrolyte is according to the present invention, and Y is Cl, Br or I, more preferably Y is Br or I, and most preferably Y is Br.

[0046] In a preferred embodiment, the solid electrolyte is according to the present invention, where Z is Cl, Br, or I, more preferably Z is Cl or I, and most preferably Z is Cl.

[0047] In a preferred embodiment, the solid electrolyte is according to the present invention, and the molar ratio of Li:M1:P:S:Y:Z, preferably the molar ratio of Li:Al:P:S:Y:Z is (5 to 6):(0 to 0.1):(0.9 to 1.1):(4.1 to 5.1):(0.1 to 1.0):(0.1 to 1.0), preferably (5.1 to 5.9):(0.01 to 0.1):(0.91 to 1.09):(4.2 to 5.0):(0.91 to 1.09):(0.2 to 0.8), more preferably (5.1 to 5.5):(0.025 to 0.075):(0.99 to 1.01):(4.3 to 4.6):(0.99 to 1.01):(0.4 to 0.7), and most preferably (5.1 It is 5.4):(0.025 to 0.075):1.0:4.4:1.0:0.6.

[0048] In a preferred embodiment, the solid electrolyte is according to the present invention and has a purity of at least 90%, preferably at least 95%, more preferably at least 99% as determined by X-ray diffraction.

[0049] In a preferred embodiment, the solid electrolyte is according to the present invention and has an F-43m space group, and preferably, as determined by least squares refinement of the XRD profile at 298 K and / or Rietveld analysis, the lattice parameters a (Å) is 9.900 to 9.9180.

[0050] In a preferred embodiment, the solid electrolyte is according to the present invention and has a conductivity of 1 to 12 mS / cm, preferably 3 to 11 mS / cm, more preferably 6 to 10 mS / cm, and most preferably 9.0 to 9.7 mS / cm.

[0051] In a preferred embodiment, the solid electrolyte is according to the present invention and, as determined by Raman spectroscopy, is 420 cm⁻¹ -1 to 430 cm -1 , preferably 421 cm -1 to 429 cm -1 , most preferably 422 cm -1 to 428 cm -1 It shows a peak at.

[0052] In some preferred embodiments, the solid electrolyte according to the present invention has diffraction peaks near 2θ = 15.5±1°, 18±1°, 25.4±1°, 30±1°, and 31±1° as determined by X-ray diffraction. In some more preferred embodiments, the solid electrolyte according to the present invention has diffraction peaks near 2θ = 44.75±0.02° and 47.63±0.02° as determined by X-ray diffraction.

[0053] In a preferred embodiment, the solid electrolyte is according to the present invention and has good moisture stability, and in particular, as determined by moisture stability, the solid electrolyte is 2.0 mmol / L after 15 minutes. -1 .g -1 Less than H2S, preferably 1.9 mmol / L after 15 minutes -1 .g -1 Less than H2S, more preferably 1.8 mmol / L after 15 minutes -1 .g -1 Less than H2S, most preferably 1.4 mmol / L after 15 minutes -1 .g -1 Less than [amount] of H2S was generated or emitted.

[0054] In a preferred embodiment, the solid electrolyte is according to the present invention and has an azirodite-type crystal structure.

[0055] In a specific preferred embodiment, the solid electrolyte is according to the present invention, and

[0056] ● Y is Br and;

[0057] ● Z is Cl and;

[0058] ● 0.01 ≤ a ≤ 0.1, preferably 0.02 ≤ a ≤ 0.09, more preferably 0.025 ≤ a ≤ 0.075;

[0059] ● 0.1 ≤ b < 0.9, preferably 0.3 ≤ b ≤ 0.8, and more preferably 0.4 ≤ b ≤ 0.7.

[0060] In a specific preferred embodiment, the solid electrolyte is according to the present invention, and

[0061] ● Y is Br and;

[0062] ● Z is Cl and;

[0063] ● 0.01 ≤ a ≤ 0.09, preferably 0.025 ≤ a ≤ 0.08, and more preferably 0.050 ≤ a ≤ 0.75;

[0064] ● 0.5 ≤ b ≤ 0.6, and preferably b is about 0.6.

[0065] In a specific preferred embodiment, the solid electrolyte is according to the present invention and has a composition according to formula (II):

[0066] Li 6-b-3a Al a PS 5-b BrCl b (II)

[0067] In a specific preferred embodiment, the solid electrolyte of the present invention is according to formula (II), 0.01 ≤ a < 0.1, preferably 0.02 ≤ a ≤ 0.09, more preferably 0.025 ≤ a ≤ 0.075, 0.1 ≤ b < 0.9, preferably 0.3 ≤ b ≤ 0.8, more preferably 0.4 ≤ b ≤ 0.7. In a specific preferred embodiment, the solid electrolyte is according to the present invention, 0.01 ≤ a ≤ 0.09, preferably 0.025 ≤ a ≤ 0.08, more preferably 0.050 ≤ a ≤ 0.75, 0.5 ≤ b ≤ 0.6, and most preferably b is about 0.6.

[0068] In a more preferred embodiment, the solid electrolyte is according to the present invention, and the solid electrolyte is according to formulas (II)a to c:

[0069]

[0070] In a preferred embodiment, the solid electrolyte of the present invention is according to formula (II) and has a purity of at least 90%, preferably at least 95%, more preferably at least 99% as determined by XRD.

[0071] In a specific preferred embodiment, the solid electrolyte of the present invention is according to formula (II) and has an F-43m space group, and preferably, the lattice parameter a (Å) is 9.900 to 9.9180 as determined by least squares refinement of the XRD profile and / or Rietveld analysis.

[0072] In a preferred embodiment, the solid electrolyte is of formula (II), preferably of formulas (II)a to c, and has a conductivity of 1 to 12 mS / cm, preferably 3 to 11 mS / cm, more preferably 6 to 10 mS / cm.

[0073] In a preferred embodiment, the solid electrolyte is according to formula (II), preferably according to formulas (II)a to (II)c, and 420 cm⁻¹ as determined by Raman spectroscopy. -1 to 430 cm -1 , preferably 421 cm -1 to 429 cm -1 , most preferably 422 cm -1 to 428 cm -1 It has a peak at.

[0074] In a preferred embodiment, the solid electrolyte is according to formula (II), preferably according to formulas (II)a to (II)c, has good moisture stability, and in particular, as determined by moisture stability, the solid electrolyte is 2.0 mmol.L after 15 minutes. -1 .g -1 Less than H2S, preferably 1.9 mmol / L after 15 minutes -1 .g -1 Less than H2S, more preferably 1.7 mmol / L after 15 minutes -1 .g -1 Less than H2S, most preferably 1.4 mmol / L after 15 minutes -1 .g -1 Less than [amount] of H2S was generated or emitted.

[0075] In a preferred embodiment, the solid electrolyte is of formula (II), preferably of formulas (II)a to c, and has an azirodite-type crystal structure.

[0076] In a specific preferred embodiment, the solid electrolyte of the present invention is according to formula (II)a and preferably has a conductivity of 9.0 to 10 mS / cm, preferably 9.25 to 9.75 mS / cm, most preferably about 9.6 mS / cm.

[0077] In a specific preferred embodiment, the solid electrolyte of the present invention is according to formula (II)b and preferably has a conductivity of 9.0 to 10 mS / cm, preferably 9.25 to 9.75 mS / cm, most preferably about 9.3 mS / cm.

[0078] In a specific preferred embodiment, the solid electrolyte of the present invention is according to formula (II)c and preferably has a conductivity of 6.0 to 7.0 mS / cm, preferably 6.25 to 6.75 mS / cm, most preferably about 6.7 mS / cm.

[0079] manufacturing method

[0080] In a second aspect, the present invention provides a method for manufacturing a solid electrolyte, and the method

[0081] a) Li, P, S, M 2 A step of providing a set of precursors including , Y and Z;

[0082] b) a step of mixing a set of precursors to obtain a solid electrolyte mixture; and

[0083] c) a step of obtaining a solid electrolyte by heat-treating a solid electrolyte mixture, and

[0084] M 2 is selected from the group consisting of B, Al, Y, Sc, Ga, In, and combinations thereof, and

[0085] Y' is selected from the group consisting of F, Cl, Br, and I, preferably Y' is F, Br, or I, more preferably Y' is Br or I, and most preferably Y' is Br,

[0086] Z' is selected from the group consisting of F, Cl, Br, and I, preferably Z' is F, Cl, or I, more preferably Z' is F or Cl, and most preferably Z' is Cl;

[0087] Y' and Z' are not the same halogen.

[0088] In a highly preferred embodiment, the method is according to the present invention, and the precursor set comprises Li2S, P2S5, Al2S3, LiY' and LiZ'.

[0089] In a preferred embodiment, the solid electrolyte is according to the present invention, and M 2 is selected from the group consisting of B, Al, Y, Sc, Ga, In and combinations thereof, preferably the group consisting of B, Al, Y, Sc, Ga, and In, more preferably the group consisting of B, Al, Ga, and In, and most preferably M 2 is Al.

[0090] In a highly preferred embodiment, the method is according to the present invention, and the solid electrolyte is a solid electrolyte according to the first aspect of the present invention, preferably a solid electrolyte according to formula (I) and / or formula (II), preferably according to formulas (II)a to c.

[0091] As understood by those skilled in the art, all embodiments relating to the solid electrolyte according to the first aspect of the present invention are methods for manufacturing the solid electrolyte according to the present invention. It is applied by analogy For example, various embodiments related to the chemical formula (I), chemical formula (II), purity level, conductivity level and moisture level described herein in the context of solid electrolytes are equally applicable to the method for manufacturing a solid electrolyte according to the present invention.

[0092] In a preferred embodiment, the method is according to the present invention, and mixing the solid electrolyte precursor of step b) may include mixing, grinding, stirring, ball milling, or a combination thereof.

[0093] In a preferred embodiment, the method is according to the present invention, and mixing the precursor set of step b) is performed at a mixing speed of at least 100 rpm, preferably at least 300 rpm, and most preferably at least 400 rpm. In a preferred embodiment, the method is according to the present invention, and mixing the precursor set of step b) is performed at a mixing speed of up to 1000 rpm, preferably at a mixing speed of up to 900 rpm, and most preferably at a mixing speed of up to 800 rpm. In a preferred embodiment, the method is according to the present invention, and mixing the precursor set of step b) is performed at a mixing speed of 100 to 1000 rpm, preferably at a mixing speed of 300 to 900 rpm, and most preferably at a mixing speed of 400 to 800 rpm.

[0094] In a preferred embodiment, the method is according to the present invention, and mixing the precursor set of step b) is performed for at least 1 hour, preferably at least 5 hours, most preferably at least 10 hours. In a preferred embodiment, the method is according to the present invention, and mixing the precursor set of step b) is performed for up to 70 hours, preferably up to 50 hours, most preferably up to 30 hours. In a preferred embodiment, the method is according to the present invention, and mixing the precursor set of step b) is performed for 1 hour to 70 hours, preferably 5 hours to 50 hours, most preferably 10 hours to 30 hours.

[0095] In a preferred embodiment, the method is according to the present invention, and mixing the solid electrolyte precursor mixture of step b) occurs at a temperature of at least 5°C, preferably at least 10°C, more preferably at least 15°C. A preferred embodiment is the method according to the present invention, and mixing the solid electrolyte precursor mixture of step b) occurs at a temperature of less than 50°C, preferably less than 40°C, more preferably less than 30°C. A preferred embodiment is the method according to the present invention, and mixing the solid electrolyte precursor mixture of step b) occurs at a temperature of 5 to 50°C, preferably 10 to 40°C, more preferably 15 to 30°C.

[0096] In a specific preferred embodiment, the method is according to the present invention, and mixing the solid electrolyte precursor of step b) is

[0097] ● With a mixing time of 1 to 70 hours, preferably 5 to 50 hours, most preferably 10 to 30 hours;

[0098] ● It is carried out at a mixing speed of 100 to 1000 rpm, preferably at a mixing speed of 300 to 900 rpm, and most preferably at a mixing speed of 400 to 800 rpm.

[0099] In a preferred embodiment, the method is according to the present invention, and the heat treatment of the solid electrolyte mixture in step c) occurs at a pressure of up to 100 Pa, preferably up to 10 Pa, more preferably up to 1 Pa. In a preferred embodiment, the method is according to the present invention, and the heat treatment of the solid electrolyte mixture in step c) occurs at least 10 -4 Pa, preferably at least 10 -3 Pa, more preferably at least 10 -2It occurs at a pressure of Pa. In a preferred embodiment, the method is according to the present invention, and heat-treating the solid electrolyte mixture of step c) is 10 -4 To 100 Pa, preferably 10 -3 To 10 Pa, more preferably 10 -2 It occurs at a pressure of 1 to 1 Pa. In a specific highly preferred embodiment, the method is according to the present invention, and before heat treatment in step c), the solid electrolyte mixture from step b) is compressed into pellets, preferably 10 mm pellets, preferably uniaxially compressed to obtain a compressed solid electrolyte mixture. Preferably, the compressed solid electrolyte mixture is placed in a pre-dried quartz tube, and then, preferably under vacuum, preferably 10 -4 To 100 Pa, preferably 10 -3 To 10 Pa, more preferably 10 -2 Flame-sealed at a pressure of 1 Pa. Afterwards, the compressed and heat-sealed solid electrolyte mixture underwent the heat treatment step of step c).

[0100] In a preferred embodiment, the method is according to the present invention, and the heat treatment of the solid electrolyte mixture in step c) occurs at a temperature of at least 100°C, preferably at least 200°C, more preferably at least 300°C, even more preferably at least 400°C, and most preferably at least 450°C. In a preferred embodiment, the method is according to the present invention, and the heat treatment of the solid electrolyte mixture in step c) occurs at a temperature of less than 1000°C, preferably less than 900°C, more preferably less than 750°C, even more preferably less than 600°C, and most preferably less than 500°C. In a preferred embodiment, the method is according to the present invention, and the heat treatment of the solid electrolyte mixture in step c) occurs at a temperature of 100 to 1000°C, preferably 300 to 750°C, and most preferably 450 to 550°C.

[0101] In a preferred embodiment, the method is according to the present invention, and the heat treatment of the solid electrolyte mixture of step c) is performed for at least 1 minute, preferably at least 0.5 hours, more preferably at least 1 hour, even more preferably at least 2.5 hours, most preferably at least 5 hours. In a preferred embodiment, the method is according to the present invention, and the heat treatment of the solid electrolyte mixture of step c) is performed for less than 48 hours, preferably less than 24 hours, more preferably less than 18 hours, even more preferably less than 12 hours, even more preferably less than 10 hours. In a preferred embodiment, the method is according to the present invention, and the heat treatment of the solid electrolyte mixture of step c) is performed for 0.5 hours to 24 hours, preferably 1 hour to 12 hours, more preferably 2.5 hours to 10 hours.

[0102] In a specific preferred embodiment, the method is according to the present invention, and heat-treating the solid electrolyte mixture of step c) is

[0103] ● Occurs at a temperature of 100 to 1000℃, preferably 300 to 750℃, most preferably 450 to 550℃;

[0104] ● It is performed for 0.5 to 24 hours, preferably 1 to 12 hours, most preferably 2.5 to 10 hours.

[0105] In a specific preferred embodiment, the method is according to the present invention, and heat-treating the solid electrolyte mixture of step c) is

[0106] ● Occurs at a temperature of 100 to 1000℃, preferably 300 to 750℃, most preferably 450 to 550℃;

[0107] ● 10 -2 To 100 Pa, preferably 10 to 10 -3 Pa, more preferably 1 to 10 -4 It occurs at a pressure of Pa.

[0108] In a specific preferred embodiment, the method is according to the present invention, and heat-treating the solid electrolyte mixture of step c) is

[0109] ● Occurs at a temperature of 100 to 1000℃, preferably 300 to 750℃, most preferably 450 to 550℃;

[0110] ● 10 -4 To 100 Pa, preferably 10 -3 To 10 Pa, more preferably 10 -2 Occurs at a pressure of 1 Pa or less;

[0111] ● It is performed for 0.5 to 24 hours, preferably 1 to 12 hours, most preferably 2.5 to 10 hours.

[0112] Quite limited product (product-by-process)

[0113] In a third aspect, the present invention relates to a solid electrolyte obtainable by the method according to the second aspect of the present invention.

[0114] As understood by those skilled in the art, all embodiments relating to a solid electrolyte according to the first aspect of the present invention and / or a method according to the second aspect of the present invention relate to a solid electrolyte obtainable by the method according to the present invention. It is applied by analogy For example, various embodiments related to the chemical formula (I), chemical formula (II), purity level, conductivity level and moisture stability level described herein in the context of solid electrolytes apply equally to solid electrolytes obtainable by methods for manufacturing solid electrolytes.

[0115] battery

[0116] A fourth aspect of the present invention relates to a battery comprising a cathode, an anode, and a solid electrolyte layer, wherein at least one of the anode, the cathode, and the solid electrolyte layer comprises a solid electrolyte according to the present invention. The solid electrolyte of the present invention may be used as a solid electrolyte layer of a solid lithium-ion battery or a solid lithium primary cell, or as a solid electrolyte mixed with an electrode mixture for a cathode or anode.

[0117] In a preferred embodiment, the battery is an all-solid-state battery, and preferably a lithium all-solid-state battery.

[0118] use

[0119] A fifth aspect of the present invention relates to the use of a solid electrolyte according to the present invention in a battery, preferably an all-solid-state battery, most preferably a lithium all-solid-state battery.

[0120] A sixth aspect of the present invention relates to the use of a battery according to the present invention in any one of a portable computer, tablet, mobile phone, energy storage system, electric vehicle, or hybrid electric vehicle, preferably in an automobile or hybrid electric vehicle.

[0121] The present invention is further illustrated in the following examples:

[0122] Examples

[0123] Explanation of the method

[0124] Synthesis protocol

[0125] All synthesis operations and sample processing were performed in an Ar-filled glove box with O2 and H2O levels below 0.1 ppm. A 2 g batch of precursor was obtained by mixing the reagents Li2S (Sigma Aldrich, 99.98%), Al2S3 (Aldrich, 98%), P2S5 (Sigma Aldrich, 99%), LiBr (Alfa Aesar, 99%), and LiCl (Alfa Aesar, 99%) in stoichiometric ratios. For CEX1, Al2S3 was not added. The precursor was transferred into an 80 mL Fritsch Pulverisette 7 premium line zirconia ball milling vessel along with 20 10 mm diameter zirconia balls (the ball-to-powder ratio was 30:1). First, the precursor was milled at 150 rpm for 30 minutes to homogenize the mixture, and then ball-milled at 600 rpm for a total duration of 20 hours. Each cycle consisted of 15 minutes of milling and 10 minutes of rest, and the milling direction was reversed for every cycle. At the end of every 8 hours of milling, the ball-milling container was opened inside a glove box to scrape off material attached to the inside of the cap and the surface of the container. The ball-milled powder was uniaxially compressed into 10 mm pellets, placed into a pre-dried quartz tube, and then vacuum (10 -2 to 10 -4It was flame-sealed under mbar and placed in a furnace (Nabertherm) for annealing. The furnace temperature was slowly increased to 525°C at a heating rate of 1.5°C / min, maintained for 5 hours, and then naturally cooled to room temperature. Afterward, the reacted pellet was ground using a mortar and pestle and stored in a glove box for further analysis.

[0126] X-ray diffraction

[0127] Powder X-ray diffraction patterns were collected using a Bruker D8 diffractometer equipped with Cu(Kα1-Kα2) or Mo(Kα1-Kα2) radiation in a θ-θ configuration. An airtight sample holder equipped with a Be window was used for the measurements. Patterns were collected at step sizes of 0.02° from 2θ = 10° to 50°. To determine the lattice parameters of the sample, profile matching using the Le Bail method was performed using the Fullprof suite.

[0128] Raman spectroscopy

[0129] Since the sample is sensitive to air, a small amount of powder was flame-sealed in a disposable glass micropipette. Spectra were collected using a Raman DXR Microscope (Thermo Fischer Scientific) equipped with a green laser with an excitation wavelength of 532 nm. A laser power of 0.1 mW was used to prevent sample damage due to excessive localized heating. Spectra were collected with an exposure time of 1 second and 180 exposures.

[0130] Ionic conductivity

[0131] Approximately 200 mg of samples were uniaxially cold-pressed in a 10 mm die at 625 MPa. The relative density of the pellets was 85 to 87%, and the thickness was approximately 1.4 mm. Indium foil was pressed onto the surface of the pellets as an ion-blocking electrode. These pellets were mounted in a BioLogic CESH cell, and AC impedance spectroscopy was performed on them. Spectra were recorded using an MTZ 35 frequency response analyzer by applying a 50 mV AC perturbation in the frequency range of 30 MHz to 1 Hz. Spectra were collected at 10°C intervals within a temperature range of -20 to 50°C using an ITS temperature controller. The AC impedance data were analyzed using Zview or RelaxIS software.

[0132] moisture stability

[0133] To prevent variations in ambient air humidity (22°C, relative humidity 29–35%), all measurements were performed on the same day. H2S detection experiments were conducted with the following configuration: approximately 30 mg of powder was pelletized in a 10 mm die, and these pellets were used for measurement. To begin the measurement, the pellets were placed on top of a rectangular polymer container inside a desiccator, and the lid of the desiccator was closed. Using an H2S sensor (Model-INS-H2S-03 (0–400 ppm, 20–90%RH)), H2S values ​​in ppm were recorded every 20 seconds for 20 minutes. The number of moles of H2S generated per liter of ambient air and per gram of sample was calculated using the following formula:

[0134]

[0135] Since the volume of the desiccator is 10 L, multiply the right-hand side by 10. Assuming that H2S behaves like an ideal gas, the inventors [describe] both sides as V, the molar volume of the ideal gas at 1 bar and RT. m (24.79 L.mol -1 Divided into ):

[0136]

[0137] Both sides are the weight of the sample (m 샘플 Normalizing with respect to ) yields the following equation:

[0138]

[0139] Using this equation, the number of moles of H2S generated per 1 L of air and 1 g of sample was plotted as a function of time, which is useful for designing large-scale production and assembly stages. In addition, the reactivity of S atoms in each material in the presence of moisture was compared. To this end, the number of moles of H2S generated per 1 L of air and 1 mol of sample after 15 minutes of exposure was calculated using the following equation:

[0140]

[0141] Here, MM 샘플 is the molar mass of the sample (assuming 100% purity) (Unit: g·mol -1 ).

[0142] Examples

[0143] Table 1 shows the overall chemical formulas and corresponding ionic conductivity of the examples synthesized through the general synthesis protocol described above.

[0144] [Table 1]

[0145] The overall chemical formulas, ionic conductivity, and lattice constants of CEX1 and EX1 to 4.

[0146]

[0147] Profile matching of powder X-ray diffraction data suggests that the azirodite structure is preserved for EX1 to 3 (space group: F4-3m; see Figs. 1a and 1b). Except for the peak at 2θ=45.86° from the Be-containing sample holder, no peaks corresponding to precursors or other impurity phases are observed. The successful synthesis of the solid electrolyte according to the present invention can be confirmed through a comparison of powder diffraction patterns, e.g., a comparison of EX1 to 3 with CEX1 (Figs. 1a and 1b). Profile matching of powder X-ray diffraction data for EX4 shows a mixed phase, which suggests that the azirodite structure is not preserved. Table 2 shows the different XRD diffraction peak positions for CEX1 and EX1 to 3.

[0148] [Table 2]

[0149] XRD diffraction peak positions

[0150]

[0151] The calculated lattice parameter values ​​obtained by performing profile matching using the Le Weil method are compiled in Fig. 2 and Table 1, showing a linear change in lattice constant values ​​following Vegard's law and confirming the successful fabrication of EX1 to 3. When the Al content increases, the cubic lattice parameters a It is shown that it gradually decreases from 9.9197 Å in CEX1 to 9.9136 Å in EX1, 9.9106 Å in EX2, and 9.9095 Å in EX3 (Fig. 2, Table 1).

[0152] Raman spectroscopy was performed to further confirm the effect of Al substitution on the structures of EX1 to 3 and CEX1. As shown in Fig. 3, the Raman spectra of all samples were 421 cm⁻¹. -1 (ν symIt exhibits a sharp peak at ), along with approximately 200, 268, 568, and 593 cm⁻¹. -1 It is accompanied by other distinct peaks, all of which correspond to different normal modes of the PS4 tetrahedron. As the Al content increases, 421 cm⁻¹ -1 Symmetric stretching mode (ν) at sym The position of ) gradually shifts toward a higher wavenumber (Fig. 3).

[0153] To maintain constant relative humidity, H2S generation measurements for all samples were performed on the same day (see Table 2). Figure 4 shows the amount of H2S generated over 15 minutes in EX1 to 3 compared to CEX1, and it is clear that the H2S generation in EX1 to 3 is significantly lower compared to CEX1.

[0154] [Table 2]

[0155] H2S measurements over 15 minutes for CEX1 and EX1 to 3.

[0156]

[0157] Electrochemical results

[0158] To achieve better performance in all-solid-state batteries, a high critical current density (CCD) of the solid electrolyte is required; this refers to the maximum current density that the cell can withstand before a short circuit caused by Li dendrites occurs. To understand the effect of Al substitution on dendrite suppression capability, CCD measurements were performed on a Li|SE|Li symmetric cell (Figs. 5a and 5b). A symmetric Li|SE|Li cell was fabricated, in which 150 mg of solid electrolyte powder was compressed at 375 MPa within a PMMA matrix between two stainless steel pistons, each having a diameter of 10 mm. Subsequently, two Li metal foils (thickness 120 to 150 microns), also having a diameter of 10 mm, were compressed on both sides of the solid electrolyte layer. The charge-discharge conditions were 25°C and a constant stack pressure of approximately 25 MPa. In the following experiment, under the same conditions, Li 5.4 PS 4.4 BrCl 0.6 and Li 5.25 Al 0.05 PS 4.4 BrCl 0.6 The constant current Li plating and stripping profiles of Li were measured. 5.4 PS 4.4 BrCl 0.6 In this case, the CCD value is 0.9 mA·cm -2 While it was, Li 5.25 Al 0.05 PS 4.4 BrCl 0.6 In this case, 1.1 mA·cm -2 It is observed that it increased. In Fig. 5b, smaller polarization was observed, which also indicates Li for Li metal 5.25 Al 0.05 PS 4.4 BrCl 0.6 It confirms the improved interfacial stability of.

Claims

Claim 1 Solid electrolyte having a composition according to chemical formula (I). 6-b-3a M 1 a PS 5-b YZ b (I) In the above chemical formula (I), 0 < a < 0.1, 0 < b < 1.0, and M 1 Y is Al, Y is selected from the group consisting of F, Cl, Br and I, Z is selected from the group consisting of F, Cl, Br and I, and Y and Z are not the same halogen. Claim 2 A solid electrolyte according to claim 1, wherein 0.01 ≤ a < 0.1, preferably 0.02 ≤ a ≤ 0.09, and more preferably 0.025 ≤ a ≤ 0.

075. Claim 3 A solid electrolyte according to claim 1 or 2, wherein 0.01 ≤ a ≤ 0.09, preferably 0.025 ≤ a ≤ 0.08, and more preferably 0.050 ≤ a ≤ 0.

75. Claim 4 A solid electrolyte according to any one of claims 1 to 3, wherein 0.1 ≤ b < 0.9, preferably 0.3 ≤ b ≤ 0.8, and more preferably 0.4 ≤ b ≤ 0.

7. Claim 5 A solid electrolyte according to any one of claims 1 to 4, wherein 0.5 ≤ b ≤ 0.6, preferably b is about 0.

6. Claim 6 A solid electrolyte according to any one of claims 1 to 5, wherein Y is F, Br, or I, more preferably Y is Br or I, and most preferably Y is Br. Claim 7 A solid electrolyte according to any one of claims 1 to 6, wherein Z is F, Cl, or I, preferably Z is Cl or I, and more preferably Z is Cl. Claim 8 A solid electrolyte having a composition according to formula (II) in any one of claims 1 to 7. 6-b-3a Al a PS 5-b BrCl b (II) Claim 9 A solid electrolyte having a composition according to formulas (II)a to (II)c in any one of claims 1 to 8. Claim 10 A solid electrolyte according to any one of claims 1 to 9, having an ionic conductivity of 1 to 12 mS / cm, preferably 3 to 11 mS / cm, more preferably 6 to 10 mS / cm. Claim 11 In any one of claims 1 to 10, measured by moisture stability, 2.0 mmol·L after 15 minutes -1 .mol -1 Less than H2S, preferably 1.9 mmol / L after 15 minutes -1 .mol -1 Less than H2S, more preferably 1.8 mmol / L after 15 minutes -1 .mol -1 Solid electrolyte that generates less than H2S. Claim 12 A method for manufacturing a solid electrolyte, preferably a solid electrolyte according to any one of claims 1 to 11, comprising: a) Li, P, S, M 2 a) providing a set of precursors including , Y' and Z'; b) mixing the set of precursors to obtain a solid electrolyte mixture; and c) heat-treating the solid electrolyte mixture to obtain a solid electrolyte; M 2 is a trivalent metal, and preferably M 2 is Al, Y' is selected from the group consisting of F, Cl, Br and I, preferably Y' is F, Br or I, more preferably Y' is Br or I, most preferably Y' is Br, Z' is selected from the group consisting of F, Cl, Br and I, preferably Z' is F, Cl or I, more preferably Z' is F or Cl, most preferably Z' is Cl, and Y' and Z' are not the same halogen, method. Claim 13 In claim 13, the set of precursors comprises Li2S, P2S5, Al2S3, LiY' and LiZ'. Claim 14 A battery comprising a negative electrode, a positive electrode, and a solid electrolyte layer, wherein at least one of the positive electrode, the negative electrode, and the solid electrolyte layer comprises a solid electrolyte according to any one of claims 1 to 12.

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