Lithium-deficient and halide-rich solid electrolytes

Abstract

The present invention relates to lithium-deficient and halide-rich solid electrolytes. These solid electrolytes exhibit enhanced ionic conductivity.

Description

Technical Field

[0001] The present invention relates to a solid electrolyte that is lithium-deficient and rich in halides, a method for manufacturing the solid electrolyte, and a battery including the solid electrolyte.

Background Art

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

[0003] However, the electrolytes conventionally used in lithium secondary batteries are liquid electrolytes made of lithium salts dissolved in organic solvents. Therefore, safety problems such as electrolyte leakage and the risk of fire can continuously occur.

[0004] Recently, in order to improve the safety characteristics of lithium secondary batteries, solid batteries including solid electrolytes instead of liquid electrolytes have been used and have received much attention. For example, solid electrolytes are typically safer than liquid electrolytes due to their incombustibility or flame retardancy.

[0005] Examples of solid electrolytes include oxide-based solid electrolytes, polymer-based electrolytes, and sulfide-based electrolytes. Sulfide-based electrolytes, for example, sulfide-based solid electrolytes having a thioargentite (argyrodite) type crystal structure, are generally used because they have a higher lithium ion conductivity range compared to oxide-based and polymer-based solid electrolytes.

[0006] International Publication No. 2020 / 033809 (A1) and Patel et al. (Chem. Mater. 2021, 33, 4, 1435 - 1443) disclose a general formula Li 6-ω PS 5-ω Cl 1.0 Brω A lithium-deficient halide-rich solid electrolyte having, for example, Li 5.7 PS 4.7 Cl 1.0 Br 0.3 and Li 5.5 PS 4.5 Cl 1.0 Br 0.5 etc. are described for synthesis.

[0007] An object of the present invention is to provide a lithium-deficient and halide-rich solid electrolyte.

[0008] A further object of the present invention is to provide a method for manufacturing the solid electrolyte.

[0009] A further object of the present invention is to provide a battery including the solid electrolyte.

Summary of the Invention

[0010] In a first aspect of the present invention, the object of the present invention is achieved by providing a solid electrolyte having a composition according to formula (I) Li 6-y PS 5-y BrX y (I) wherein 0.0 < y < 0.8 and X is F, Cl, I, or a combination thereof.

[0011] The inventors have surprisingly found that these lithium-deficient halide-rich solid electrolyte compositions exhibit increased ionic conductivities up to 9.9 mS·cm -1 as demonstrated in the attached examples. In particular, high conductivities are measured even at low temperatures, making these compositions suitable for low-temperature applications. Furthermore, these solid electrolyte compositions according to the present invention show a reduction in H2S gas generation upon contact with moisture, making them more attractive for commercial production and use in batteries.

[0012] While not wishing to be bound by any theory, the inventors believe that X- / S 2- The site irregularity is increased by excessive and / or mixed halide substitution, whereby S 2- and X - is considered to affect the lithium substructure by altering the position of the Li + site. Furthermore, when a sulfide electrolyte containing a PS4 tetrahedron reacts with moisture, sulfur in the PS4 is replaced by oxygen, generating H2S gas. This insufficient moisture stability of known thio-germanite such as Li6PS5Br and Li6PS5Cl may be mainly due to the oxophilicity of phosphorus. However, substituting S 2- in the composition with halides reduces H2S generation, as shown in the attached examples.

[0013] In a further aspect, the present invention provides a method for manufacturing the solid electrolyte.

[0014] The inventors have surprisingly found that an electrolyte precursor mixture containing stoichiometric ratios of Li2S, P2S5, LiBr, and LiCl needs to be ball-milled for at least 0.5 hours. WO 2020 / 033809 (A1) teaches that disclosed solid electrolyte compositions such as Li 5.7 PS 4.7 Cl 1.0 Br 0.3 and Li 5.7 PS 4.7 Cl 1.0 I 0.3 are obtained after 10 minutes of ball-milling. However, these ball-milling conditions, particularly the ball-milling time of the solid electrolyte precursor, are not sufficient to obtain the solid electrolyte composition according to the present invention.

[0015] In a further aspect, the present invention provides a battery comprising the solid electrolyte according to the present invention.

Brief Description of the Drawings

[0016]

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Mode for Carrying Out the Invention

[0017] To enable the implementation of the present invention, preferred embodiments will be described in detail in the drawings and the following forms for carrying out the invention. The present invention is described with reference to these specific preferred embodiments, but it will be understood that the present invention is not limited to these preferred embodiments. On the contrary, the present invention includes numerous alternatives, modifications, and equivalents as will become apparent by considering the following forms for carrying out the invention and the accompanying drawings.

[0018] As used in this specification and the claims, the term "comprising" should not be construed as being limited to the means recited thereafter, and does not exclude other elements or steps. It should be construed as specifying the presence of the described features, integers, steps, or components as recited, but does not exclude the presence or addition of one or more other features, integers, steps, or components, or groups thereof. Thus, the scope of the expression "a composition comprising components A and B" should not be limited to a composition consisting only of components A and B. It means, with respect to the present invention, that the only relevant components of the composition are A and B. Thus, the terms "comprising" and "including" encompass the more restrictive terms "consisting essentially of" and "consisting of".

[0019] As used herein, the term "solid battery" refers to a cell or battery that includes only solid or substantially solid components such as solid electrodes (e.g., an anode and a cathode) and a solid electrolyte.

[0020] As used herein, the term "argyrodite-type crystal structure" refers to a crystal structure having a crystal structure or system similar to that of naturally occurring Ag8GeS6 and Li7S6 (argyrodite). The argyrodite-type crystal structure can be orthorhombic symmetry, but is more likely to be cubic symmetry and can be described by the F-43m space group. In some embodiments, the argyrodite-type crystal structure can also be experimentally determined by X-ray diffraction, for example, by observing diffraction peaks around 2θ = 15.5 ± 1°, 18 ± 1°, 26 ± 1°, 30.5 ± 1° and 32 ± 1° using CuKα radiation wavelength.

[0021] As referred to herein, X-ray diffraction (XRD) refers to an XRD experiment performed using a Bruker D8 diffractometer equipped with either Cu(Kα1-Kα2) or Mo(Kα1-Kα2) radiation in a θ-θ configuration.

[0022] Preferably, an airtight sample holder capped with a Be window (almost transparent to X-rays) is used. Preferably, the pattern was collected between 2θ = 10° and 70° with a step size of 0.02°.

[0023] As referred to herein, Raman spectroscopy refers to a Raman experiment performed using a Raman DXR microscope (Thermo Fischer Scientific) equipped with a green laser with an excitation wavelength of 532 nm. Preferably, a laser output of 0.1 mW was used to avoid sample damage due to excessive local heating. Preferably, the spectrum was collected with an exposure time of 1 second and 180 exposures.

[0024] Unless otherwise specified, the ionic conductivity referred to in this specification refers to the ionic conductivity measured at 25°C. Preferably, it was measured for a sample cold-pressed at 625 MPa in a 10 mm die using a BioLogic CESH cell, and the spectrum was recorded using an MTZ 35 frequency response analyzer by applying an AC perturbation of 50 mV at frequencies in the range of 30 MHz to 1 Hz. Preferably, the relative density of the pellet was 85 - 87% and the thickness was about 1.4 mm. Preferably, indium foil was pressed onto the surface of the pellet as an ion-blocking electrode. More preferably, spectra were collected at intervals of 10°C between -20 and 50°C in an ITS temperature controller.

[0025] The moisture stability referred to in this specification refers to measuring the amount of H2S recorded in ppm every 20 seconds for 20 minutes using an H2S sensor (model - INS - H2S - 03 (0 - 400 ppm, 20 - 90% RH)). Preferably, about 45 mg of powder was pelletized in a 10 mm die, the pellet was placed on a rectangular polymer container in a desiccator, and the lid of the desiccator was closed. The number of moles of H2S produced per liter of ambient air and per gram of sample was calculated using the following formula.

Equation

[0026] As will be understood by those skilled in the art, the bromine content present in the composition according to formula (I), particularly the composition according to formula (I), has the following stoichiometric ratio. Li 6-y PS 5-y BrX y (I)=Li 6-y PS 5-y Br 1.0 X y (I)’

[0027] As used herein, the term "solid electrolyte precursor mixture" refers to an electrolyte precursor mixture that is essentially free of liquid. The term "essentially free of liquid" means that the solid electrolyte precursor mixture contains less than 10% by weight, preferably less than 7.5% by weight, more preferably less than 5% by weight, even more preferably less than 2.5% by weight, and most preferably less than 1% by weight of liquid, based on the total weight of the solid electrolyte precursor mixture. In a more preferred embodiment, the solid electrolyte precursor mixture contains less than 1000 ppm, preferably less than 500 ppm, more preferably less than 100 ppm, even more preferably less than 50 ppm, and most preferably less than 10 ppm of liquid, based on the total weight of the solid electrolyte precursor mixture.

[0028] In the context of the present invention, a liquid is considered to be an organic or aqueous compound that is liquid under standard conditions of temperature and pressure as defined by the IUPAC. Accordingly, the boiling point and melting point are considered to be those at standard atmospheric pressure, i.e., 101325 Pa. As will be understood by those skilled in the art, the presence of an organic liquid can be determined by thermogravimetric analysis (TGA) or nuclear magnetic resonance (NMR) spectroscopy, and the presence of an aqueous liquid can be determined by Karl Fischer titration.

[0029] As used herein, the term "solid electrolyte mixture" refers to an electrolyte mixture that is essentially free of any liquid. The term "essentially free of liquid" means that the solid electrolyte mixture contains less than 10% by weight, preferably less than 7.5% by weight, more preferably less than 5% by weight, even more preferably less than 2.5% by weight, and most preferably less than 1% by weight of liquid, based on the total weight of the solid electrolyte mixture. In a more preferred embodiment, the solid electrolyte mixture contains less than 1000 ppm, preferably less than 500 ppm, more preferably less than 100 ppm, even more preferably less than 50 ppm, and most preferably less than 10 ppm of liquid, based on the total weight of the solid electrolyte mixture.

[0030] As used herein, the term "solid electrolyte" refers to an electrolyte that essentially contains no liquid. The term "essentially free of liquid" means that the solid electrolyte contains less than 10% by weight, preferably less than 7.5% by weight, more preferably less than 5% by weight, even more preferably less than 2.5% by weight, and most preferably less than 1% by weight of liquid based on the total weight of the solid electrolyte. In a more preferred embodiment, the solid electrolyte contains less than 1000 ppm, preferably less than 500 ppm, more preferably less than 100 ppm, even more preferably less than 50 ppm, and most preferably less than 10 ppm of liquid based on the total weight of the solid electrolyte.

[0031] Solid electrolyte In a first aspect, the present invention provides a solid electrolyte having a composition according to formula (I) Li 6-y PS 5-y BrX y (I) where 0.0 < y < 0.8 and X is F, Cl, I, or a combination thereof.

[0032] In a preferred embodiment, the solid electrolyte is according to the present invention and 0.01 ≤ y ≤ 0.79, preferably 0.05 ≤ y ≤ 0.75, more preferably 0.075 ≤ y ≤ 0.725, even more preferably 0.09 ≤ y ≤ 0.71, and most preferably 0.1 ≤ y ≤ 0.7. In certain preferred embodiments, the solid electrolyte is according to the present invention and 0.4 ≤ y ≤ 0.7, preferably 0.5 ≤ y ≤ 0.7, more preferably 0.55 ≤ y ≤ 0.65.

[0033] In certain preferred embodiments, the solid electrolyte is according to the present invention and 0.01 ≤ y ≤ 0.59, preferably 0.05 ≤ y ≤ 0.55, more preferably 0.075 ≤ y ≤ 0.52, even more preferably 0.09 ≤ y ≤ 0.51, and most preferably 0.1 ≤ y ≤ 0.5.

[0034] In certain preferred embodiments, the solid electrolyte is according to the present invention, where X is F, Cl, I, or a combination thereof, preferably X is Cl, I, or a combination thereof, and preferably X is Cl.

[0035] In certain preferred embodiments, the solid electrolyte is according to the present invention, where X is F, Cl, or I, preferably X is Cl or I, and preferably X is Cl.

[0036] According to a preferred embodiment of the present invention, there is provided a solid electrolyte in which at least 50 mol% of X represents Cl, preferably at least 80 mol% of X represents Cl, and most preferably X represents Cl.

[0037] According to a preferred embodiment of the present invention, there is provided a solid electrolyte in which X represents Cl, F, I, or a combination thereof, and at least 50 mol% of X represents Cl, preferably at least 80 mol% of X represents Cl.

[0038] According to a preferred embodiment of the present invention, there is provided a solid electrolyte in which at least 50 mol% of X represents F, preferably at least 80 mol% of X represents F, and most preferably X represents F.

[0039] According to a preferred embodiment of the present invention, there is provided a solid electrolyte in which X represents Cl, F, I, or a combination thereof, and at least 50 mol% of X represents F, preferably at least 80 mol% of X represents F.

[0040] According to a preferred embodiment of the present invention, there is provided a solid electrolyte in which at least 50 mol% of X represents I, preferably at least 80 mol% of X represents I, and most preferably X represents I.

[0041] According to a preferred embodiment of the present invention, there is provided a solid electrolyte in which X represents Cl, Br, I, or a combination thereof, and at least 50 mol% of X represents I, preferably at least 80 mol% of X represents I.

[0042] In certain preferred embodiments, the solid electrolyte is according to the present invention, wherein, · X is Cl, · 0.01 ≤ y ≤ 0.79, preferably 0.09 ≤ y ≤ 0.71, most preferably 0.1 ≤ y ≤ 0.7.

[0043] In certain preferred embodiments, the solid electrolyte is according to the present invention, wherein, · X is Cl, · 0.4 ≤ y ≤ 0.7, preferably 0.5 ≤ y ≤ 0.7, most preferably 0.55 ≤ y ≤ 0.65.

[0044] In certain preferred embodiments, the solid electrolyte is according to the present invention, wherein, · X is Cl, · 0.01 ≤ y ≤ 0.59, preferably 0.05 ≤ y ≤ 0.55, more preferably 0.075 ≤ y ≤ 0.52, even more preferably 0.09 ≤ y ≤ 0.51, most preferably 0.1 ≤ y ≤ 0.5.

[0045] In certain preferred embodiments, the solid electrolyte is according to the present invention, wherein, · X is I, · 0.0 < y < 0.5, preferably 0.01 ≤ y ≤ 0.49, more preferably 0.05 ≤ y ≤ 0.45, even more preferably 0.09 ≤ y ≤ 0.41, most preferably 0.1 ≤ y ≤ 0.4.

[0046] In certain preferred embodiments, the solid electrolyte is according to the present invention, wherein, · X is I, · 0.05 ≤ y ≤ 0.35, preferably 0.075 ≤ y ≤ 0.325, more preferably 0.1 ≤ y ≤ 0.3.

[0047] In a more preferred embodiment, the solid electrolyte is according to the present invention, and the solid electrolyte is according to Formula (I) a - g. [Table 1]

[0048] In a preferred embodiment, the solid electrolyte is according to the present invention, has an F-43m space group, and preferably has a lattice constant a (Å) of 10.00 to 9.90, preferably 9.99 to 9.91, more preferably 9.985 to 9.915, as determined by XRD profile and / or least-squares refinement of Rietveld analysis.

[0049] In a preferred embodiment, the solid electrolyte is according to the present invention and has a thio-germanate silver ore type crystal structure.

[0050] In a preferred embodiment, the solid electrolyte is according to the present invention, and the molar ratio of Li:P:S:Br:X is (5 to 6):(0.9 to 1.1):(4 to 5):(0.9 to 1.1):(0.01 to 0.79), preferably (5.1 to 5.9):(0.91 to 1.09):(4.1 to 4.9):(0.91 to 1.09):(0.05 to 0.75), more preferably (5.29 to 5.91):(0.99 to 1.01):(4.29 to 4.91):(0.99 to 1.01):(0.09 to 0.71), and most preferably (5.3 to 5.9):1:(4.3 to 4.9):1:(0.1 to 0.7).

[0051] In a preferred embodiment, the solid electrolyte is according to the present invention and has a conductivity of 1 to 12 mS / cm, preferably 2 to 10 mS / cm, and most preferably 6 to 10 mS / cm.

[0052] In a specific preferred embodiment, the solid electrolyte is according to the present invention, wherein ·X is Cl, ·0.4 ≦ y ≦ 0.7, preferably 0.5 ≦ y ≦ 0.7, and most preferably 0.55 ≦ y ≦ 0.65, ·The solid electrolyte is 5 to 12 mS·cm -1 preferably 5.5 to 11 mS·cm -1 and most preferably 6 to 10 mS·cm -1has a conductivity of

[0053] In certain preferred embodiments, the solid electrolyte is according to the present invention, · The solid electrolyte is Li 5.5 PS 4.5 BrCl 0.5 and · The solid electrolyte has a conductivity of 0.1 mS·cm -1 ~1.9 mS·cm -1 , preferably 0.5 mS·cm -1 ~1.5 mS·cm -1 , most preferably about 1 mS·cm -1 and the conductivity is measured at -20 °C.

[0054] 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 XRD.

[0055] In a preferred embodiment, the solid electrolyte is according to the present invention and has peaks at 420 cm -1 ~430 cm -1 , preferably 421 cm -1 ~429 cm -1 , most preferably 422 cm -1 ~428 cm -1 as determined by Raman spectroscopy.

[0056] In a preferred embodiment, the solid electrolyte is according to the present invention and has good moisture stability. In particular, the solid electrolyte generates or releases less than 5.0 mmol·L -1 .g -1 of H2S after 15 minutes, preferably less than 4.5 mmol·L -1 .g -1 of H2S after 15 minutes, more preferably less than 4.0 mmol·L -1 .g -1 of H2S as determined by moisture stability.

[0057] Manufacturing method In a second aspect, the present invention is a method for manufacturing a solid electrolyte, comprising: a) providing a solid electrolyte precursor mixture comprising Li2S, P2S5, LiBr, and LiX; b) mixing the solid electrolyte precursor mixture to obtain a solid electrolyte mixture; c) heat-treating the solid electrolyte mixture to obtain a solid electrolyte, where X is a halogen selected from F, Cl, I, or combinations thereof, preferably X is selected from Cl, I, or combinations thereof, and most preferably X is Cl.

[0058]

[0058] In a highly preferred embodiment, the method is according to the present invention, and the solid electrolyte is the solid electrolyte according to the first aspect of the present invention.

[0059] As will be understood by those skilled in the art, all embodiments related to the solid electrolyte according to the first aspect of the present invention are equally applicable to the method for manufacturing the solid electrolyte according to the present invention.

[0060] In a preferred embodiment, the method is according to the present invention, and the mixing of the solid electrolyte precursors in step b) is for at least 15 minutes, preferably at least 0.5 hour, and most preferably at least 1 hour.

[0061] In a preferred embodiment, the method is according to the present invention, and the mixing of the solid electrolyte precursors in step b) is for 1 hour to 60 hours, preferably 5 hours to 45 hours, and most preferably 10 hours to 30 hours.

[0062] In a preferred embodiment, the method is according to the present invention, and the mixing of the solid electrolyte precursors in step b) is carried out at a mixing speed of 100 to 1000 rpm, preferably 300 to 900 rpm, and most preferably 400 to 800 rpm.

[0063] In a preferred embodiment, the method is according to the present invention, and the mixing of the solid electrolyte precursor in step b) is carried out 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 the mixing of the solid electrolyte precursor in step b) is carried out 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 the mixing of the solid electrolyte precursor in step b) is carried out at a temperature of 5 to 50°C, preferably 10 to 40°C, more preferably 15 to 30°C.

[0064] In a specific preferred embodiment, the method is according to the present invention, and the mixing of the solid electrolyte precursor in step b) is · carried out with a mixing time of 1 hour to 60 hours, preferably 5 hours to 45 hours, most preferably 10 hours to 30 hours, · carried out at a mixing speed of 100 to 1000 rpm, preferably 300 to 900 rpm, most preferably 400 to 800 rpm.

[0065] In a specific preferred embodiment, the method is according to the present invention, and step b) is b1) a step of mixing the solid electrolyte precursor mixture to obtain a solid electrolyte pre-mixture, · carried out with a mixing time of 1 minute to 10 hours, preferably 5 minutes to 5 hours, most preferably 15 minutes to 3 hours, · carried out at a mixing speed of 1 to 500 rpm, preferably 50 to 300 rpm, most preferably 100 to 200 rpm, and b2) a step of mixing the solid electrolyte pre-mixture to obtain a solid electrolyte mixture, · carried out with a mixing time of 1 hour to 60 hours, preferably 5 hours to 45 hours, most preferably 10 hours to 30 hours, · carried out at a mixing speed of 100 to 1000 rpm, preferably 300 to 900 rpm, most preferably 400 to 800 rpm, and includes.

[0066] In a preferred embodiment, the method is according to the present invention, and the heat treatment of the solid electrolyte mixture in step c) is carried out at a temperature of at least 100°C, preferably at least 200°C, more preferably at least 300°C, even more preferably at least 350°C, and most preferably at least 400°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) is carried out 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) is carried out at a temperature of 100 to 1000°C, preferably 300 to 750°C, and most preferably 450 to 550°C.

[0067] In a preferred embodiment, the method is according to the present invention, and the heat treatment of the solid electrolyte mixture in step c) is at least 1 minute, preferably at least 0.5 hour, more preferably at least 1 hour, even more preferably at least 1.5 hours, and most preferably at least 2 hours. In a preferred embodiment, the method is according to the present invention, and the heat treatment of the solid electrolyte mixture in step c) is less than 48 hours, preferably less than 24 hours, more preferably less than 18 hours, even more preferably less than 12 hours, and 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 in step c) is 0.5 hour to 24 hours, preferably 1 hour to 12 hours, and more preferably 1.5 hours to 10 hours.

[0068] In a specific preferred embodiment, the method is according to the present invention, and the heat treatment of the solid electrolyte mixture in step c) is · carried out at a temperature of 100 to 1000°C, preferably 300 to 750°C, and most preferably 450 to 550°C, · 0.5 hour to 24 hours, preferably 1 hour to 12 hours, and most preferably 1.5 hours to 10 hours.

[0069] Composite positive electrode active material The third aspect of the present invention relates to a composite positive electrode active material including a positive electrode active material and a solid electrolyte according to the first aspect of the present invention.

[0070] As used herein and in the claims, the term "positive electrode active material" (also known as a cathode active material) is defined as a material that is electrochemically active in a positive electrode or cathode. It should be understood that an active material is a material that can capture and release Li ions when exposed to a voltage change over a predetermined period of time.

[0071] In a preferred embodiment, the positive electrode active material (also known as a cathode active material) contains Li, M, and O, and M contains Ni and one or both of Mn and Co. Preferably, the cathode active material contains Li, M, and O, and M is - Ni with a content x of 50.0 mol% ≤ x ≤ 95.0 mol% with respect to M, - Mn with a content y of 0.0 mol% ≤ y ≤ 40.0 mol% with respect to M, - Co with a content z of 0.0 mol% ≤ z ≤ 40.0 mol% with respect to M, - D with a content a of 0.0 mol% ≤ a ≤ 2.0 mol% with respect to M, where D is at least one element other than Li, Ni, Mn, Co, and O, - x + y + z + a is 100.0 mol%, More preferably, M is - Ni with a content x of 55.0 mol% ≤ x ≤ 85.0 mol% with respect to M, - Mn with a content y of 10.0 mol% ≤ y ≤ 30.0 mol% with respect to M, - Co with a content z of 10.0 mol% ≤ z ≤ 30.0 mol% with respect to M, - D with a content a of 0.0 mol% ≤ a ≤ 2.0 mol% with respect to M, where D is at least one element other than Li, Ni, Mn, Co, and O, - x + y + z + a is 100.0 mol%, Most preferably, M is - Ni with a content x of 58.0 mol% ≤ x ≤ 70.0 mol% with respect to M, - Mn with a content y of 15.0 mol% ≤ y ≤ 25.0 mol% with respect to M, - Co with a content z of 15.0 mol% ≤ z ≤ 25.0 mol% with respect to M, - D with a content a of 0.0 mol% ≤ a ≤ 2.0 mol% with respect to M, where D is at least one element other than Li, Ni, Mn, Co, and O, - x + y + z + a is 100.0 mol%.

[0072] In some particularly preferred embodiments, x is about 60 mol%, y is about 20 mol%, and z is about 20 mol%. This is also known as NMC 622.

[0073] In a preferred embodiment of the present invention, D is at least one element selected from the group consisting of Al, Ti, B, Ba, Ca, Cr, Fe, Mg, Mo, Nb, S, Si, Sr, V, W, Y, Zn, and Zr; preferably, Al, B, Ti, Cr, Nb, S, Si, Y, Zr, and W; more preferably, Al, B, Ti, Nb, Zr, and W.

[0074] In some particularly preferred embodiments, a = 0.0 mol%.

[0075] In a preferred embodiment, the Li / M ratio (mol / mol) is 0.9 to 1.1, preferably 0.95 to 1.05, more preferably 0.99 to 1.01, and most preferably about 1.

[0076] As will be understood by those skilled in the art, the amounts of Li and M, preferably Li, Ni, Mn, and Co, in the positive electrode active material are measured by Inductively Coupled Plasma - Optical Emission Spectroscopy (ICP - OES). For example, without limitation to the present invention, Agilent ICP 720 - ES is used in ICP - OES analysis.

[0077] In certain preferred embodiments, the solid electrolyte is of formula (I), where 0.4 ≤ y ≤ 0.7, preferably 0.5 ≤ y ≤ 0.7, more preferably 0.55 ≤ y ≤ 0.65. In certain preferred embodiments, the solid electrolyte is of formula (I)f.

[0078] In certain preferred embodiments, the solid electrolyte is of formula (I), where 0.01 ≤ y ≤ 0.59, preferably 0.05 ≤ y ≤ 0.55, more preferably 0.075 ≤ y ≤ 0.52, even more preferably 0.09 ≤ y ≤ 0.51, and most preferably 0.1 ≤ y ≤ 0.5.

[0079] In a preferred embodiment, the composite cathode active material is - 55 to 95 wt%, preferably 65 to 85 wt%, more preferably 65 to 75 wt% of the cathode active material based on the total weight of the composite cathode active material, and - 5 to 55 wt%, preferably 15 to 35 wt%, more preferably 25 to 35 wt% of the solid electrolyte according to the first aspect of the present invention based on the total weight of the composite cathode active material.

[0080] In a highly preferred embodiment, the composite cathode active material of the present invention comprises a cathode active material as defined herein and a solid electrolyte according to the first aspect of the present invention, The cathode active material contains Li, M, and O, where M is - Ni with a content x of 58.0 mol% ≤ x ≤ 70.0 mol% relative to M, - Mn with a content y of 15.0 mol% ≤ y ≤ 25.0 mol% relative to M, - Co with a content z of 15.0 mol% ≤ z ≤ 25.0 mol% relative to M, - D with a content a of 0.0 mol% ≤ a ≤ 2.0 mol% relative to M, where D is at least one element other than Li, Ni, Mn, Co, and O, - x + y + z + a = 100.0 mol%, The solid electrolyte is of the formula (I), where 0.4 ≦ y ≦ 0.7, preferably 0.5 ≦ y ≦ 0.7, more preferably 0.55 ≦ y ≦ 0.65.

[0081] In a highly preferred embodiment, the composite cathode active material of the present invention comprises a cathode active material as defined herein and a solid electrolyte according to the first aspect of the present invention, and the cathode active material comprises Li, M, and O, where M is - Ni with a content of x = 60 mol% relative to M, - Mn with a content of y = 20 mol% relative to M, - Co with a content of z = 20 mol% relative to M, and the solid electrolyte is of the formula (I)f.

[0082] Battery A fourth aspect of the present invention relates to a battery comprising a negative electrode, a positive electrode, and a solid electrolyte layer, wherein at least one of the cathode, anode, and solid electrolyte layer contains the solid electrolyte according to the present invention. The solid electrolyte of the present invention can be used as the solid electrolyte layer of a solid lithium-ion battery or a solid primary lithium battery, or as a solid electrolyte mixed with the electrode mixture of the positive electrode or the negative electrode.

[0083] In a preferred embodiment, the battery is a solid-state battery, preferably a lithium solid-state battery.

[0084] As will be understood by those skilled in the art, the negative electrode is the anode and the positive electrode is the cathode. Accordingly, the present invention relates to a battery comprising a negative electrode, a positive electrode, and a solid electrolyte layer, wherein at least one of the positive electrode, negative electrode, and solid electrolyte layer contains the solid sulfide electrolyte according to the present invention.

[0085] As will be understood by those skilled in the art, the solid electrolyte layer is a separator layer or a membrane layer that separates the anode and the cathode from each other. A specific preferred embodiment is a battery according to the present invention, wherein the positive electrode contains the composite cathode active material according to the third aspect of the present invention.

[0086] A specific preferred embodiment is a battery according to the present invention, wherein the positive electrode contains a further positive electrode active material containing Li, M', and O, and the solid electrolyte layer contains a solid electrolyte according to the first aspect of the present invention.

[0087] As will be appreciated, the positive electrode as defined herein may contain a composite positive electrode active material according to the third aspect of the present invention and / or a further positive electrode active material as defined herein, but may further contain other components that are not electrochemically active, in particular a conductive agent such as carbon black or a binder such as PVDF.

[0088] The further positive electrode active material contains Li, M', and O, and M' contains Ni and one or both of Mn and Co. Preferably, the positive electrode active material contains Li, M', and O, and M' is - Ni with a content x' of 50.0 mol% ≤ x' ≤ 95.0 mol% with respect to M', - Mn with a content y' of 0.0 mol% ≤ y' ≤ 40.0 mol% with respect to M', - Co with a content z' of 0.0 mol% ≤ z' ≤ 40.0 mol% with respect to M', - D' with a content a' of 0.0 mol% ≤ a' ≤ 2.0 mol% with respect to M', where D' is at least one element other than Li, Ni, Mn, Co, and O, and - x' + y' + z' + a' = 100.0 mol%, More preferably, M' is - Ni with a content x' of 55.0 mol% ≤ x' ≤ 85.0 mol% with respect to M', - Mn with a content y' of 10.0 mol% ≤ y' ≤ 30.0 mol% with respect to M', - Co with a content z' of 10.0 mol% ≤ z' ≤ 30.0 mol% with respect to M', - D' with a content a' of 0.0 mol% ≤ a' ≤ 2.0 mol% with respect to M', where D' is at least one element other than Li, Ni, Mn, Co, and O, and - x' + y' + z' + a' = 100.0 mol%, Most preferably, M' is - Ni with a content x' of 58.0 mol% ≤ x' ≤ 70.0 mol% with respect to M', - Mn with a content y' of 15.0 mol% ≤ y' ≤ 25.0 mol% with respect to M', - Co with a content z' of 15.0 mol% ≤ z' ≤ 25.0 mol% with respect to M', - D' with a content a' of 0.0 mol% ≤ a' ≤ 2.0 mol% with respect to M', where D' is at least one element other than Li, Ni, Mn, Co, and O, - x' + y' + z' + a' is 100.0 mol%.

[0089] In a preferred embodiment of the present invention, D' is Al, Ti, B, Ba, Ca, Cr, Fe, Mg, Mo, Nb, S, Si, Sr, V, W, Y, Zn, and Zr; preferably, Al, B, Ti, Cr, Nb, S, Si, Y, Zr, and W; more preferably, at least one element selected from the group consisting of Al, B, Ti, Nb, Zr, and W.

[0090] In some particularly preferred embodiments, a' = 0.0 mol%.

[0091] In some particularly preferred embodiments, x' is about 60 mol%, y' is about 20 mol%, and z' is about 20 mol%. This is also known as NMC 622.

[0092] In a preferred embodiment, the Li / M' ratio (mol / mol) is 0.9 to 1.1, preferably 0.95 to 1.05, more preferably 0.99 to 1.01, and most preferably about 1.

[0093] As will be understood by those skilled in the art, the amounts of Li and M, preferably Li, Ni, Mn, and Co, in the further cathode active material are measured by inductively coupled plasma optical emission spectrometry (ICP-OES). For example, without limitation to the present invention, an Agilent ICP 720-ES is used in ICP-OES analysis.

[0094] In certain preferred embodiments, the solid electrolyte layer comprises a solid electrolyte according to the first aspect of the present invention. More preferably, the solid electrolyte layer consists of a solid electrolyte according to the first aspect of the present invention.

[0095] In certain preferred embodiments, the solid electrolyte layer comprises a further solid electrolyte having a composition different from that of the solid electrolyte according to the first aspect of the present invention. Preferably, the further solid electrolyte having a composition different from that of the solid electrolyte according to the present invention is a sulfide solid electrolyte, and more preferably, the further solid electrolyte having a composition different from that of the solid electrolyte according to the present invention contains Li, P, and S. Typically, the following sulfur-containing compounds, where X = Cl, Br, I, or a combination thereof, are Li6PS5X, thio-LISICON (Li 3.25 Ge 0.25 P 0.75 S4), Li2S-P2S5-LiCl, Li2S-SiS2, LiI-Li2S-SiS2, Li2S-P2S5-LiCl, Li2S-SiS2, LiI-Li2S-SiS2, LiI-Li2S-P2S5, LiI-Li2S-P2O5, LiI-Li3PO4-P2S5, Li2S-P2S5, Li3PS4, Li7P3S 11 、LiI-Li2S-B2S3, Li3PO4-Li2S-SiS2, Li3PO4-Li2S-SiS2, Li3PO4-Li2S-SiS2, Li 10 GeP2S 12 、Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 、and / or Li7P3S 11 can be preferably used. Even more preferably, the further solid electrolyte having a composition different from that of the solid electrolyte according to the present invention is a thio-germanium silver ore type solid electrolyte, most preferably Li6PS5Cl.

[0096] Thus, in certain preferred embodiments, it is a battery according to the present invention, · The positive electrode contains a composite positive electrode active material as defined herein, · The solid electrolyte layer contains a solid electrolyte according to the first aspect of the present invention.

[0097] In another specific preferred embodiment, a battery according to the present invention, · The positive electrode contains a composite positive electrode active material as defined herein, · The solid electrolyte layer contains a further solid electrolyte having a composition different from that of the solid electrolyte of the first aspect of the present invention.

[0098] In another specific preferred embodiment, a battery according to the present invention, · The positive electrode contains a further positive electrode active material containing Li, M', and O as defined herein and a further solid electrolyte having a composition different from that of the solid electrolyte as defined herein, · The solid electrolyte layer contains the solid electrolyte according to the first aspect of the present invention.

[0099] In a specific very preferred embodiment, a battery according to the present invention, · The positive electrode contains a positive electrode active material containing Li, M, and O, where M is - Ni with a content x of 58.0 mol% ≤ x ≤ 70.0 mol% with respect to M, - Mn with a content y of 15.0 mol% ≤ y ≤ 25.0 mol% with respect to M, - Co with a content z of 15.0 mol% ≤ z ≤ 25.0 mol% with respect to M, - D with a content a of 0.0 mol% ≤ a ≤ 2.0 mol% with respect to M, where D is at least one element other than Li, Ni, Mn, Co, and O, D, - x + y + z + a is 100.0 mol%, and contains a solid electrolyte according to formula (I), where 0.4 ≤ y ≤ 0.7, preferably 0.5 ≤ y ≤ 0.7, more preferably 0.55 ≤ y ≤ 0.65, · The solid electrolyte layer contains the solid electrolyte according to formula (I), where 0.4 ≤ y ≤ 0.7, preferably 0.5 ≤ y ≤ 0.7, more preferably 0.55 ≤ y ≤ 0.65.

[0100] In a more specific very preferred embodiment, a battery according to the present invention, · The positive electrode contains a positive electrode active material containing Li, M, and O, where M is - Ni with a content x = 60 mol% relative to M, - Mn with a content y = 20 mol% relative to M, - Co with a content z = 20 mol% relative to M, and includes It includes a solid electrolyte according to formula (I)f, · The solid electrolyte layer contains a solid electrolyte according to formula (I)f.

[0101] In a preferred embodiment, the negative electrode contains a negative electrode active material. Suitable electrochemically active negative electrode materials are known in the art. For example, the anode may contain a lithium-containing metal alloy such as graphite carbon, metallic lithium, or a Li-In alloy as the negative electrode active material. Preferably, the negative electrode further includes a solid sulfide electrolyte according to the first aspect of the present invention and / or a further solid electrolyte having a composition different from that of the solid electrolyte of the first aspect of the present invention as defined herein. Preferably, the further solid electrolyte having a composition different from that of the solid electrolyte according to the present invention is a sulfide solid electrolyte, more preferably, the further solid electrolyte having a composition different from that of the solid electrolyte according to the present invention contains Li, P, and S, and even more preferably, the further solid electrolyte having a composition different from that of the solid electrolyte according to the present invention is a thio-Li6PS5Cl.

[0102] In a preferred embodiment, the battery of the present invention has a discharge capacity of at least 150 mAh / g, preferably at least 155 mAh / g, and more preferably at least 160 mAh / g. As understood by those skilled in the art, the discharge capacity is obtained within a voltage range of 1.9 - 3.6 V with respect to the LiIn / In reference electrode at room temperature at a C rate of C / 30.

[0103] Method for manufacturing a battery The fifth aspect of the present invention is a method for manufacturing a battery, preferably a battery according to the fourth aspect of the present invention, comprising the following steps: (a) Providing a positive electrode, preferably a positive electrode as defined herein; (b) Providing a negative electrode, preferably a negative electrode as defined herein; (c) Providing a solid electrolyte layer as defined herein; (d) Forming a battery by assembling the positive electrode, negative electrode, and solid electrolyte layer into the battery. A method is related to this.

[0104] A preferred embodiment is a method for manufacturing a battery, wherein step (d) includes forming the battery by pressing the positive electrode, negative electrode, and solid electrolyte layer at 300 - 400 MPa, preferably about 375 MPa, for 1 - 30 minutes, preferably about 5 minutes.

[0105] As will be understood by those skilled in the art, all embodiments related to the battery according to the fourth aspect of the present invention are applied with the necessary modifications to the method for manufacturing the battery. For example, various embodiments regarding the compositions of the cathode, anode, and solid electrolyte layer described herein in the context of the battery are equally applicable to the method for manufacturing the battery.

[0106] Use The sixth aspect of the present invention relates to the use of the solid electrolyte according to the present invention in a battery, preferably a solid battery, most preferably a lithium solid battery.

[0107] The seventh aspect of the present invention relates to the use of the battery according to the present invention in any one of a portable computer, a tablet, a mobile phone, an energy storage system, an electric vehicle, or a hybrid electric vehicle, preferably in any one of an electric vehicle or a hybrid electric vehicle.

[0108] The present invention is further illustrated in the following examples.

Examples

[0109] Description of the test method Synthesis protocol All synthesis operations and sample treatments were carried out in an Ar-filled glove box with O2 and H2O levels <0.1 ppm. For each example of the stoichiometric ratio of the reagents, Li2S (Sigma Aldrich, 99.98%), P2S5 (Sigma Aldrich, 99%), LiBr (Alfa Aesar, 99%), and LiCl (Alfa Aesar, 99%) were mixed to obtain a 2 g batch of the precursor. The precursor was transferred to a Fritsch Pulverisette 7 premium line 80 mL zirconia ball mill grinding jar together with 20 zirconia balls with a diameter of 10 mm (the ball:powder ratio was 30:1 (mass ratio)). The precursor was first ground at 150 rpm for 30 minutes to homogenize the mixture, and then ball milled at 600 rpm for a total of 20 hours. Each cycle consisted of 15 minutes of grinding and 10 minutes of rest, and the direction of grinding was reversed every cycle. After every 8 hours of grinding, the ball mill grinding jar was opened inside the glove box, and the material adhering to the cap and the inner surface of the jar was scraped off. After the ball milling process, approximately 90 wt% of the material was recovered. The ball milled powder was uniaxially pressed into 10 mm pellets, placed in a pre-dried quartz tube, and then this was frame sealed under vacuum (10 -2 mbar) and placed in a furnace (manufactured by Nabertherm) for annealing. The temperature of the furnace was slowly raised to 450 °C at a heating rate of 1.5 °C / min, held for 5 hours, and then naturally cooled to room temperature. Then, the reacted pellets were ground using a mortar and pestle and stored in the glove box for further analysis.

[0110] X-ray diffraction Powder X-ray diffraction patterns were collected using a Bruker D8 diffractometer equipped with Cu(Kα1-Kα2) or Mo(Kα1-Kα2) radiation in θ-θ configuration. An airtight sample holder with a Be window was used for the measurement. The patterns were collected between 2θ = 10° and 50° with a step size of 0.02°. Profile matching was performed using the Le Bail method with the Fullprof suite to determine the lattice constants of the samples.

[0111] Raman spectroscopy The 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 output of 0.1 mW was used to avoid sample damage due to excessive local heating. The spectra were collected with an exposure time of 1 second and 180 exposures.

[0112] Ionic conductivity Approximately 200 mg of the sample was uniaxially cold pressed at 625 MPa in a 10 mm die. The relative density of the pellet was 85 - 87% and the thickness was approximately 1.4 mm. Indium foil was pressed onto the surface of the pellet as an ion blocking electrode. By mounting these pellets in a BioLogic CESH cell, AC impedance spectroscopy was performed on these pellets, and the spectra were recorded using an MTZ 35 frequency response analyzer by applying an AC perturbation of 50 mV at frequencies in the range of 30 MHz to 1 Hz. Spectra were collected at temperatures in the range of -20 to 50 °C at 10 °C intervals in an ITS temperature controller. The AC impedance data was analyzed using Zview or RelaxIS software.

[0113] Water stability All measurements were performed on the same day to avoid changes in humidity in the ambient air. The H2S sensing experiment was carried out in the following setup: Approximately 45 mg of the powder was pelletized in a 10 mm die, and these pellets were used for the measurements. To start the measurement, the pellet was placed on a rectangular polymer container inside a desiccator, and the lid of the desiccator was closed. The H2S value in ppm was recorded every 20 seconds for 20 minutes using an H2S sensor (model - INS - H2S - 03 (0 - 400 ppm, 20 - 90% RH)). The number of moles of H2S generated per liter of ambient air and per gram of sample was calculated using the following equation.

Equation

[0114] Since the desiccator has a volume of 10 L, the right side is multiplied by 10. Assuming that H2S behaves like an ideal gas, both sides are divided by V m which is the molar volume of an ideal gas at 1 bar and RT (24.79 L / mol -1 ). [Number]

[0115] Normalizing both sides with respect to the weight (m sample ) of the sample gives the following. [Number]

[0116] Using this equation, the number of moles of H2S generated per liter of air and per gram of sample was plotted as a function of time, which is useful for designing larger-scale production and assembly stages. Further, the reactivity of S atoms in each material in the presence of moisture is compared. For this purpose, the number of moles of H2S generated per liter of air and per mole of sample after 15 minutes of exposure is calculated using the following equation. [Number] where MM sample is the molar mass of the sample in g / mol -1 assuming 100% purity).

[0117] Examples Synthesis of Solid Electrolytes Table 1 shows the overall formulas of the examples synthesized via the above general synthesis protocol, along with their corresponding ionic conductivities. Also, EX6 was observed to exhibit an ionic conductivity of 1 mS / cm -1 even at -20 °C, which makes EX6 a very interesting composition for low-temperature applications.

[0118] Profile matching of the powder X-ray diffraction data suggests that the argyrodite structure is preserved in EX1-7 (space group: F4-3m). Peaks corresponding to precursors or other impurity phases are not observed except for the peak at 2θ = 45.6° from the Be-containing sample holder. Further increase in the Cl content (CEX5) results in the formation of further impurities (see Figures 1a and 1b). As shown in Figure 2, the success of the synthesis of CEX1-3 and EX5 without any impurities is confirmed from the powder diffraction patterns.

Table 2

[0119] The calculated lattice constant values obtained by performing profile matching using the Le Bail method in the fullprof suite collected in Figure 3 show a linear variation of the lattice constant values according to Vegard's law with x, confirming the successful preparation of EX1-7. Cl - As the content is increased, as shown in Figure 3, it is shown that the cubic lattice constant a gradually decreases from 9.993 Å for CEX4 to 9.908 Å for EX7.

[0120] Raman spectroscopy was performed to further confirm the effect of Cl - substitution on the structures of EX1-7 and CEX5. As shown in Figures 4a and 4b, the Raman spectra of all samples show sharp peaks at 421 cm -1 (ν sym ) and further prominent peaks at approximately 200, 268, 568, and 593 cm -1 , all of which correspond to different reference modes of the PS4 tetrahedron. As the Cl - content increases, the position of the symmetric stretching mode (ν -1 ) at 421 cm sym gradually shifts towards higher wavenumbers (see Figures 4a and 4b).

[0121] To maintain a constant relative humidity, the H2S generation measurements for all samples were taken on the same day. Figure 5 shows the amount of H2S generated over 15 minutes for EX3, EX5, and EX7 with respect to CEX4 and commercially available sulfide germanite Li6PS5Cl. As shown in Figure 5, it is clear that H2S generation is significantly less for EX3, EX5, and EX7 compared to commercially available Li6PS5Cl and CEX4.

[0122] Battery assembly 1) Preparation of cathode composite: The cathode composite was prepared by manually grinding 70 wt% NMC-622 and 30 wt% solid electrolyte in an agate mortar and pestle for 20 minutes. No additional conductive carbon was added to the composite.

[0123] 2) Anode composite: The anode composite was prepared by manually grinding a 60:40 weight ratio of Li 0.5 In alloy and Li6PS5Cl for 1 hour until a dark gray powder was obtained.

[0124] 3) Battery assembly: Battery assembly and electrochemical tests were carried out using a PMMA (polymethyl methacrylate) matrix and two stainless steel pistons with a diameter of 10 mm. All assembly procedures were carried out under an argon atmosphere in a glove box ([O2] < 1 ppm, [H2O] < 1 ppm).

[0125] The cell was assembled as follows. a. Approximately 49 mg of solid electrolyte was added to the PMMA matrix and cold pressed at 125 MPa for 1 minute under hydraulic pressure. b. 20 - 22 mg of the cathode composite was evenly spread on one side of the solid electrolyte (NMC filling amount: 14 - 15 mg). c. 85 mg of the anode composite was evenly spread on the other side of the solid electrolyte. d. The entire stack was compressed at 375 MPa for 5 minutes. e. The cell was transferred to a stainless-steel frame and a uniaxial stack pressure of 100 MPa was applied using a torque wrench. f. Subsequently, the entire assembly was transferred to a sealed glass jar for further electrochemical testing.

[0126] Electrochemical cycle protocol: A constant-current cycle test was performed at room temperature within a potential range of 1.9 - 3.6 V versus a LiIn / In reference electrode. The first charge-discharge cycle was carried out at a C-rate of C / 30. (C corresponds to 0.6 moles of Li per mole of active material in 1 hour). Subsequently, cycling was performed at different C-rates including C / 15, C / 10, C / 5, C / 2, and 1C. Each C-rate was repeated for a total of 6 cycles. For the evaluation of long-term cycle stability, the cell was subjected to 50 consecutive cycles at a C / 5 rate.

[0127] Results: Table 2 shows the specific capacity and retention rate of a battery (EX8) comprising a cathode composite that is NMC622 and Li 5.4 PS 4.4 BrCl 0.6 and a solid electrolyte layer that is Li 5.4 PS 4.4 BrCl 0.6 and a battery (CEX6) comprising a cathode composite that is NMC622 and Li6PS5Cl and a solid electrolyte that is Li6PS5Cl.

Table 3

[0128] Figures 6 and 7 show the rate performance and long-term cycle stability of batteries comprising cathode composites containing different weight % of NMC-622 and Li 5.4 PS 4.4 BrCl 0.6 In these batteries, the solid electrolyte layer is also Li 5.4 PS 4.4 BrCl 0.6 as well.

Claims

1. A solid electrolyte having a composition according to formula (I), where 0.0 < y < 0.8, and X is F, Cl, I, or a combination thereof. Li ６－ｙ PS ５－ｙ BrX ｙ (I)

2. The solid electrolyte according to claim 1, wherein 0.05 ≤ y ≤ 0.75, preferably 0.075 ≤ y ≤ 0.725, more preferably 0.1 ≤ y ≤ 0.

7.

3. The solid electrolyte according to claim 1 or 2, wherein X is F, Cl, or I, preferably X is Cl or I, and more preferably X is Cl.

4. The solid electrolyte according to any one of claims 1 to 3, wherein 0.4 ≤ y ≤ 0.7, preferably 0.5 ≤ y ≤ 0.7, more preferably 0.55 ≤ y ≤ 0.

65.

5. The solid electrolyte according to any one of claims 1 to 4, wherein 0.01 ≤ y ≤ 0.59, preferably 0.05 ≤ y ≤ 0.55, more preferably 0.09 ≤ y ≤ 0.

51.

6. The solid electrolyte according to any one of claims 1 to 5, wherein X is Cl and 0.1 ≤ y ≤ 0.

7.

7. The solid electrolyte according to any one of claims 1 to 3, wherein X is I and 0.0 < y < 0.

4.

8. The solid electrolyte according to claim 7, wherein 0.05 ≤ y ≤ 0.35, preferably 0.075 ≤ y ≤ 0.325, more preferably 0.1 ≤ y ≤ 0.

3.

9. a - g of formula (I): 【Table 1】 The solid electrolyte according to any one of claims 1 to 6, having a composition according to the following.

10. The solid electrolyte according to any one of claims 1 to 9, having the F - 43m space group and preferably having a lattice constant a (Å) of 10.00 - 9.90 as determined by Rietveld analysis.

11. The solid electrolyte according to any one of claims 1 to 10, having an ionic conductivity of 1 - 12 mS / cm, preferably 2 - 10 mS / cm, more preferably 6 - 10 mS / cm.

12. The solid electrolyte according to any one of claims 1 to 11, having a purity of at least 90%, preferably at least 95%, more preferably at least 99% as determined by XRD.

13. As determined by the water stability, 5.0 mmol.L after 15 minutes －１ .g －１ Less than H ２ The solid electrolyte according to any one of claims 1 to 12, which generates S A method for manufacturing a solid electrolyte, preferably the solid electrolyte according to any one of claims 1 to 13, comprising: a) Li ２ S, P ２ S ５ providing a solid electrolyte precursor mixture comprising S, LiBr, and LiX b) mixing the solid electrolyte precursor mixture to obtain a solid electrolyte mixture; c) heat - treating the solid electrolyte mixture to obtain a solid electrolyte. In the formula, X is a halogen selected from F, Cl, I, or a combination thereof. A method for manufacturing a solid electrolyte.

15. The method according to claim 14, wherein the mixing of the solid electrolyte precursor in step b) is at least 0.5 hours.

16. A composite positive electrode active material comprising a positive electrode active material and the solid electrolyte according to any one of claims 1 to 13, wherein the positive electrode active material contains Li, M, and O, and M contains Ni and one or both of Mn and Co. A composite positive electrode active material.

17. M is - Ni with a content x of 50.0 mol% ≤ x ≤ 95.0 mol% with respect to M, - Mn with a content y of 0.0 mol% ≤ y ≤ 40.0 mol% with respect to M, - Co with a content z of 0.0 mol% ≤ z ≤ 40.0 mol% with respect to M, - D with a content a of 0.0 mol% ≤ a ≤ 2.0 mol% with respect to M, where D is at least one element other than Li, Ni, Mn, Co, and O, and D, - The composite positive electrode active material according to claim 16, wherein x + y + z + a = 100.0 mol%.

18. 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 contains the solid electrolyte according to any one of claims 1 to 13.

19. The battery according to claim 18, wherein the positive electrode contains the composite positive electrode active material according to claim 16 or 17.

20. The battery according to claim 18 or 19, wherein the solid electrolyte layer contains the solid electrolyte according to any one of claims 1 to 13.

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