Sulfide-based solid electrolyte, its production and use, and solid-state battery cell containing it

Abstract

The invention relates to a sulfide-based solid electrolyte comprising or consisting of the general chemical formula (I): Li 6 M1 a M2 b S 5 X1 x X2y formula (I), where M1 is selected from the group consisting of P and Sb; M2 is selected from the group consisting of Si, Sn and W; a = 1.0 and 0.1 ≤ b ≤ 1.0; X1 and X2 are each independently selected from the group consisting of Cl, Br and I; where: x + y = 2 and X1 ≠ X2. The sulfide-based solid electrolyte is characterized by high electrochemical performance, such as high ionic conductivity and (electro-)chemical stability. The sulfide-based solid electrolyte according to the invention can be produced in a two-stage milling process without a heating step and in a shorter time than the known crystalline sulfide-based solid electrolytes, whereby the time, energy and cost required for production can be significantly reduced.

Description

[0001] The invention relates to a sulfide-based solid electrolyte, its production and use, and a solid-state battery cell containing it.

[0002] In battery technology, lithium-ion-based battery systems have become increasingly popular in recent years. These systems are characterized in particular by their high energy density and expected long service life, enabling more efficient battery configurations. The high chemical reactivity and low mass of lithium ions, as well as their high mobility, play a key role here. In solid-state batteries, both electrodes and the electrolyte are made of solid material. In lithium-ion batteries, lithium compounds are present in all three phases of the electrochemical cell; i.e., the negative electrode, the positive electrode, and the electrolyte contain lithium ions from solid-state lithium-ion conductors.The general advantage of lithium-based solid-state batteries is that they replace a liquid electrolyte, which is often highly flammable or toxic and prone to decomposition, thus improving the safety and reliability of lithium-based batteries.

[0003] The development of lithium-based solid-state batteries with high power output, high capacity, and good (electro)chemical stability is of great interest, especially for electric vehicles. For high battery performance, a solid-state electrolyte material with good ionic conductivity is generally desirable to achieve the highest possible battery power output.

[0004] One problem with the production of known sulfide solid-state electrolytes with a crystalline structure for solid-state batteries is that the process is time-consuming, energy-intensive, and costly. This is particularly important in the context of scaling up sulfide solid-state electrolytes, i.e., with regard to suitability for mass production.

[0005] Conventional sulfide solid-state electrolytes for solid-state batteries are produced via a so-called solid-state synthesis, which consists of two steps: 1. The starting materials are ground in a ball mill to obtain a homogeneous powder mixture, the powder having an amorphous morphology. 2. The resulting powder is heated to approximately 550 °C for 20 hours or more under vacuum or argon. Heating produces a powder with a crystalline morphology, with the degree of crystallization generally increasing with increasing heating temperature and longer heating time.

[0006] The disadvantages of this conventional solid-state synthesis for obtaining crystalline or glass-ceramic sulfide solid-state electrolytes are the high temperatures, the long processing time, the high energy consumption, and the high costs. However, these disadvantages must be accepted in order to obtain the desired material properties.

[0007] Representative of the conventional solid-state synthesis to produce crystalline, sulfidic solid electrolytes, reference is made, for example, to Thorben Krauskopf et al. (1)where the starting mixture for the production of a solid electrolyte is ball milled at 400 rpm for 48 hours, and then pressed as a pellet under vacuum to 773 K (499.85 °C) and annealed for 20 hours.

[0008] According to Laidong Zhou et al. (2) Although the conventional ball milling process is not used, high temperatures and a long time are still necessary to produce the solid electrolyte. Thus, the starting materials are used as mixtures for the production of Li 6+x Si x Sb 1-x S 5 l was heated in vacuum for 7 days to 550 °C (0.5 ≤ x ≤ 0.7) or 500 °C (0.1 ≤ x ≤ 0.4), each at a ramp rate of 5 °C / min. To produce Li 6 Sb x P 1-x S 5 l is heated to 550 °C (0.1 ≤ x ≤ 0.4) or 500 °C (0.5 ≤ x ≤ 1) for 100 h at a ramp rate of 5 °C / min and used to produce Li 6+x Ge x Sb 1-x S 5I is heated to 550 °C for 50 hours at the same ramp rate.

[0009] Furthermore, Subin Song et al. (3) Solid-state electrolytes from Li 10 GeP 2 S 12 -type. For their production, the starting materials Li 2 S, P 2 S 5 , LiBr and LiI were weighed in the specified molar ratios and ground by planetary ball milling for 40 h. Subsequently, the pellets were sealed in a quartz tube at 5 Pa and heated in an oven in the temperature range of 463 - 493 K (189.85 °C - 219.85 °C) for 4 h. For example, the solid-state electrolytes Li 10 P 3 S 12 Br and Li 10.25 P 3 S 12.25 I 0.75 described.

[0010] There are also state-of-the-art approaches to improve manufacturing conditions: For example, Tomoyuki Tsujimura et al. (4) the compounds (1-x)LiCl-xLiBr-2Li3 PS 4 (x = 0, 0.25, 0.50, 0.75, and 1.0), which are produced by high-energy ball milling, which involves grinding for 16.5 h under argon and crystallizing in a furnace at various heat treatment temperatures for 12 h under vacuum. For example, Li 7 P 2 S 8 I, Li 7 P 2 S 8 Br 0.5 I 0.5 , Li 7 P 2 S e I 0.5 Cl 0.5 or Li 7 P 2 S 8 I 0.7 sBr 0.25 manufactured.

[0011] Furthermore, Wo Dum Jung et al. (5) the production of Li 5,2 Si 0,2 Sb 0,8 S 4 Br 0,25 I 17,5in a mechanical-chemical synthesis without annealing. The starting materials are weighed in the specified stoichiometric ratios, mixed, and then subjected to a two-stage milling process in a planetary ball mill. The first milling process is carried out at 550 rpm for 12 hours, with milling for 30 minutes followed by a 30-minute break, and this cycle is repeated 12 times. The second milling process is carried out at 800 rpm for 3 hours, with milling for 30 minutes followed by a 15-minute break, and this cycle is repeated 4 times.

[0012] There remains a great need to provide sulfide-based solid-state electrolytes with improved manufacturing processes and good performance.

[0013] The present invention is therefore based on the object of avoiding the disadvantages of the prior art and providing a sulfide-based solid electrolyte which has comparable electrochemical performance, in particular ionic conductivity and (electro-)chemical stability, as known crystalline, sulfidic solid electrolytes, but does not require the disadvantageous conditions for the production process known from the prior art.

[0014] According to the invention, the above object is achieved by a sulfide-based solid electrolyte with a crystalline or glass-ceramic structure, comprising or consisting of the general chemical formula (I): Li 6 M1 a M2 b S 5 X1 x X2 y Formula (I), where M1 is selected from the group consisting of P and Sb; M2 is selected from the group consisting of Si, Sn and W; a = 1.0 and 0.1 ≤ b ≤ 1.0; X1 and X2 are each independently selected from the group consisting of Cl, Br and I; where x + y = 2 and X1 # X2.

[0015] Therefore, a sulfide-based solid electrolyte with the general chemical formula (I) is provided. The terms "sulfide-based solid electrolyte," "sulfidic solid electrolyte," and "sulfide solid electrolyte" should be understood as synonymous and interchangeable.

[0016] The sulfide-based solid electrolyte of the invention represents a novel solid electrolyte which can have a glass-ceramic or crystalline morphology, i.e. it can have either both crystalline and amorphous components simultaneously or exclusively a crystalline structure.

[0017] It is known that crystalline, sulfidic solid-state electrolytes, such as Li 10 GeP 2 S 12 (LGPS) and Li 6 PS 5 Cl (argyrodite) (see Subin Song et al. (3) and Laidong Zhou et al. (2) ), usually have a higher electrochemical performance than amorphous or glass-ceramic solid-state electrolytes, ie solid-state electrolytes with crystalline and amorphous components. However, the sulfide-based solid-state electrolyte according to the invention, which can have a glass-ceramic or crystalline structure, also shows high electrical performance. The sulfide-based solid-state electrolyte has a high ionic conductivity at 25°C (σ RT ) of > 4 mS*cm -1 Stable high current densities of 1 mA* cm -2 or more measured.

[0018] In the general chemical formula (I), M1 is either phosphorus (P) or antimony (Sb) and M2 is either silicon (Si), tin (Sn) or tungsten (W).

[0019] For the parameters a and b, a = 1.0 and 0.1 ≤ b ≤ 1.0; where a + b = 1.1 to 2.0.

[0020] According to a preferred embodiment, the following applies to the general chemical formula (I): 0.1 ≤ b ≤ 0.95 or 0.15 ≤ b ≤ 0.95 or 0.2 ≤ b ≤ 0.9 or 0.25 ≤ b ≤ 0.85 or 0.25 ≤ b ≤ 0.8, in particular 0.3 ≤ b ≤ 0.75 or 0.3 ≤ b ≤ 0.7 or 0.35 ≤ b ≤ 0.7.

[0021] According to a preferred embodiment, the general chemical formula (I) is: 1.2 ≤ a + b ≤ 2.0 or 1.25 ≤ a + b ≤ 2.0 or 1.3 ≤ a + b ≤ 2.0 or 1.35 ≤ a + b ≤ 1.9 or 1.4 ≤ a + b ≤ 1.9, in particular 1.4 ≤ a + b ≤ 1.85 or 1.4 ≤ a + b ≤ 1.8 .

[0022] In the general chemical formula (I), X1 is selected from Cl, Br, or I; X2 is also selected from Cl, Br, or I. However, X1 and X2 should be selected differently from each other, such that X1 ≠ X2. This means that if, for example, X1 = Cl, then X2 cannot be Cl, but only Br or I.

[0023] The variables x + y together equal 2, where x > 0 and y > 0 also apply. According to one embodiment, x can be in the range from 0.1 to 1.9 and y is then in the range from 1.9 to 0.1. Preferably, x is in the range from 0.3 to 1.7, in particular in the range from 0.4 to 1.7 or 0.5 to 1.65 or 0.6 to 1.6, in particular in the range from 0.75 to 1.5. Preferably, y is in the range from 1.7 to 0.3, in particular in the range from 1.6 to 0.3 or 1.5 to 0.35 or 1.4 to 0.4, in particular in the range from 1.25 to 0.5.

[0024] According to a preferred embodiment, x = 1 and y = 1.

[0025] It has been found to be particularly advantageous if the halogens in the general chemical formula (I) are present in a superstoichiometric amount, ie (x + y) > 1. In particular, if this is maintained, advantageous electrochemical properties such as high ionic conductivity and stable high current density are achieved.

[0026] The invention also relates to a process for producing the sulfide-based solid electrolyte comprising the following steps: (a) providing the starting materials of the sulfide-based solid electrolyte, preferably in the form of sulfide and / or halide salts, (b) weighing the starting materials in the amounts according to the specified stoichiometry in the general formula (I) of the sulfide-based solid electrolyte of the present invention; (c) first grinding the weighed quantities of starting materials in a ball mill at 300 to 500 rpm for more than 10 h; (d) second grinding of the mixture obtained in step (c) at 500 to 800 rpm in a ball mill for less than 10 h and (e) obtaining the sulfide-based solid electrolyte, wherein steps (b), (c) and (d) are carried out in an inert gas atmosphere with exclusion of moisture or in a vacuum with exclusion of moisture.

[0027] In step (a), the starting materials of the sulfide-based solid-state electrolyte are first prepared. These are, for example, commercially available salts, preferably in the form of sulfide and / or halide salts. The salts are preferably used in a purity of ≥ 98%, more preferably ≥ 98.5%, even more preferably ≥ 99.0%, in particular ≥ 99.5% or ≥ 99.9% or ≥ 99.98%, or even ≥ 99.99% purity.

[0028] In step (b), the starting materials are then weighed in (super-)stoichiometric amounts according to the general formula (I). The weighing is carried out under an inert gas atmosphere or in a vacuum, i.e., without the presence of oxygen, and with exclusion of moisture. An inert gas atmosphere is, for example, a noble gas such as argon or nitrogen gas, and the like. Exclusion of moisture means, for example, a content of H 2 O < 0.6 ppm. Compliance with an O 2 -content < 0.6 ppm may be appropriate.

[0029] After weighing in step (b), the starting materials can optionally be mixed, or you can proceed directly to step (c). If mixing is carried out, this should also be done under an inert gas atmosphere or under vacuum, and preferably under an O 2 -content < 0.6 ppm and preferably under exclusion of moisture, e.g. H 2O < 0.6 ppm.

[0030] In the subsequent step (c), the weighed quantities of starting materials are subjected to a first grinding step. The first grinding step is carried out at a relatively low number of revolutions per minute in a ball mill. Grinding takes place at 300 to 500 rpm. Preferably, 300 to 450 rpm is used, more preferably 350 to 450 rpm, and in particular, about 400 rpm is used.

[0031] The first milling step according to step (c) is preferably carried out for a duration in the range of 11 h to 18 h, more preferably 11 h to 16 h, even more preferably 11 h to 14 h or 11 h to 13 h or 11 h to 12 h, in particular about 11 h. Preferably, the milling in the first milling step (c) is not interrupted, but carried out continuously.

[0032] In a second milling step (d), the mixture obtained in step (c) is milled in a ball mill, preferably at a higher number of revolutions per minute than in the first milling step. Milling in the second milling step takes place at 500 to 800 rpm. Preferably, 500 to 750 rpm are used, more preferably 500 to 700 rpm, even more preferably 550 to 700 rpm, and in particular, about 650 rpm are used.

[0033] The second milling step according to step (d) is preferably carried out for a duration in the range of 3 h to 9 h, more preferably 4 h to 8 h, even more preferably 5 h to 7 h, especially 5 h to 6 h, or about 5.5 h. The milling in step (d) is preferably not interrupted, but carried out continuously.

[0034] The first milling step (c) is therefore preferably carried out at a lower number of revolutions per minute and for a longer duration than in step (d) in a ball mill and the second milling step (d) is preferably carried out at a higher number of revolutions per minute and for a shorter duration than in step (c) in a ball mill.

[0035] In the two grinding steps (c) and (d) any type of ball mill can be used in which the material is milled under an inert gas atmosphere or under vacuum and preferably under an O 2 -content < 0.6 ppm and preferably under exclusion of moisture, e.g. H 2 O < 0.6 ppm, grinding can be carried out. A planetary ball mill is particularly preferably used according to the invention. The balls of the ball mill can be selected, for example, from steel, stone, porcelain, or ceramic. Balls made of ceramic materials, e.g., ZrO, are preferred. 2. The same ball mill is preferably used in both grinding steps (c) and (d).

[0036] Preferably, the second grinding step (step (d)) follows the first grinding step (step (c)) immediately and without an intermediate step.

[0037] After the two milling steps, the sulfide-based solid electrolyte is obtained in step (e).

[0038] The form in which the sulfide-based solid electrolyte with a crystalline or glass-ceramic structure can be present is not further restricted. Preferably, the sulfide-based solid electrolyte obtained in step (e) is subjected to a further grinding step to obtain a powder. The average particle diameter (d50) of this powder is preferably in the range of 0.1 µm to 50 µm. Grinding is preferably carried out again under an inert gas atmosphere or under vacuum and with the exclusion of moisture and oxygen, as already explained.

[0039] In the process according to the invention, a heating step is no longer required for the synthesis of the sulfide-based solid electrolyte. In particular, annealing is no longer necessary. The costs of the manufacturing process can therefore be significantly reduced. In addition, a significantly shorter period of time is required to prepare the solid electrolyte than with conventional solid-state synthesis. This also means a significant reduction in energy consumption. This has a particularly significant impact on large-scale production, enabling easier upscaling of the solid electrolyte material for industrial-scale production. Overall, the process of the invention is improved over the known prior art processes in terms of both time, energy, and cost. This also means a significant improvement in CO 2 -Balance sheet.

[0040] In addition, the sulfide-based solid-state electrolytes produced by the process according to the invention show a similarly high electrochemical performance compared to other crystalline sulfide-based solid-state electrolytes, such as LGPS or argyrodite, which are generally known for their high electrochemical performance (ionic conductivity / (electro-)chemical stability).

[0041] The invention also relates to the use of the sulfide-based solid electrolyte in a solid-state battery cell.

[0042] The invention also relates to a solid-state battery cell comprising the sulfide-based solid electrolyte according to the present invention. Preferably, the solid-state battery cell is a high-power cell.

[0043] The solid-state battery cell of the present invention can be a primary battery or a secondary battery, preferably a secondary battery that can be repeatedly charged and discharged. Primary batteries can be discharged only once and cannot be recharged thereafter. Secondary batteries, also referred to as accumulators, are rechargeable. For example, the solid-state battery cell of the present invention can be installed in an electrically powered vehicle (BEV, battery electric vehicle).

[0044] Preferably, a solid-state battery cell comprises a cathode material layer, an anode material layer and an electrolyte layer arranged therebetween, wherein the sulfide-based solid-state electrolyte according to the invention is present in one, two or all three layers.

[0045] The anode material layer of a solid-state battery cell, for example, comprises at least one anode-active material and may contain a solid electrolyte material, a conductive material, and a binder. The anode-active material layer preferably contains the inventive sulfide-based solid electrolyte with a crystalline or glass-ceramic structure, for example in a proportion of 0.1 to 80 vol.%. Furthermore, a metal such as In, Al, Si, and Sn may be present as anode-active material. The anode material layer may further contain a conductive material, for example selected from carbon black, graphitized carbon black, graphite, carbon nanotubes, and carbon nanofibers, or combinations thereof. Furthermore, the anode material layer may comprise a binder, such as polyvinylidene fluoride (PVDF). The thickness of the anode material layer is preferably in a range from 0.1 µm to 1000 µm.

[0046] The cathode material layer of a solid-state battery cell, for example, comprises at least one cathode-active material and may contain a solid electrolyte material, a conductive material, and a binder. The cathode-active material layer preferably contains the sulfide-based solid electrolyte according to the invention, for example in a proportion of 0.1 to 80 vol.%. For example, a cathode-active material may be LiCoO. 2 , LiNiO 2 or Li y No (1-p-w )M p N w O 2 where 0.8 ≤ y ≤ 1.2, 0 ≤ p ≤ 0.33, 0 ≤ w ≤ 0.33, where M and N are selected from Mn, Co, Al. Furthermore, in particular, a conductive material and a binder, as described, for example, for the anode material layer, are present. The thickness of the cathode material layer is preferably in the range from 0.1 µm to 1000 µm.

[0047] The electrolyte layer of a solid-state battery cell is located between the cathode material layer and the anode material layer and enables ionic conduction. The electrolyte layer preferably contains the sulfide-based solid electrolyte according to the invention, present in a proportion of 10 to 100 vol. The thickness of the electrolyte layer is preferably in the range of 0.1 µm to 1000 µm, for example in the range of 0.1 µm to 300 µm.

[0048] The solid-state battery cell has a separator that spatially and electrically separates the anode and cathode. According to a preferred embodiment, the separator of the solid-state battery cell has a sulfide-based solid electrolyte.

[0049] It is further preferred if the particle size (d50) of the sulfide-based solid electrolyte of the cathode composition is smaller than the particle size (d50) of the active cathode material. It is further preferred if the particle size (d50) of the sulfide-based solid electrolyte used in the cathode composition is smaller than the particle size (d50) of the sulfide-based solid electrolyte used for the separator.

[0050] The sulfide-based solid-state electrolyte exhibits particularly good properties, is particularly advantageous to manufacture and can therefore be used advantageously in solid-state battery cells. Manufacturing example:

[0051] Sulfide-based solid electrolyte materials of the present invention according to formula (I) were prepared using a mechanical ball mill as described below: For this purpose, Li 2 S (99.9%+ purity), P 2 S5 (99.9%+ purity), SnS 2 (99.9%+ purity), LiBr (99.9%+ purity) and LiI (99.9%+ purity) in the amounts for the specified stoichiometry in an argon-filled glove box with < 0.6 ppm H 2 O and < 0.6 ppm O 2 weighed. The weighed chemicals were mixed and ground in a zirconia planetary ball mill in a glove box for 11 hours using a Fritsch Pulverisette 7 Premium Series at 450 rpm in the first grinding step. The powder was then ground in the same zirconia planetary ball mill (Fritsch Pulverisette 7 Premium Series) for 5.5 hours at 650 rpm in the second grinding step. After grinding, the desired sulfide-based solid-state electrolyte was obtained. Literature list (1) Thorben Krauskopf et al.: “Bottleneck of Diffusion and Inductive Effects in Li 10 Ge 1-x Sn x P 2 S 12“ in Chem. Mater. 2018, 30, S. 1791-1798; (2) Laidong Zhou et al.: „New Family of Argyrodite Thioantimonate Lithium Superionic Conductors“ in J. Am. Chem. Soc. 2019, 141, S. 19002-19013; (3) Subin Song et al.: „Material Search for a Li 10 GeP 2 S 12 -Type Solid Electrolyte in the Li-P-S-X (X = Br, I) System via Clarification of the Composition-Structure-Property Relationships“ in Chem Mater. 2022, 34, S. 8237-8247; (4) Tomoyuki Tsujimura et al.: „Synthesis and characterization of low-temperature lithium-ion conductive phase of LiX(X = Cl, Br)-Li 3 PS 4 solid electrolytes“ in Solid State lonics 383, 2022, 115970, S. 1-8; und (5) Wo Dum Jung et al.: „Annealing-Free Thioantimonate Argyrodites with High Li-Ion Conductivity and Low Elastic Modulus“ in Adv. Funct. Mater. 2023, 33, 2211185, S. 1 bis 11. ZITATE ENTHALTEN IN DER BESCHREIBUNG

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited non-patent literature

[0000] Thorben Krauskopf et al.: “Bottleneck of Diffusion and Inductive Effects in Li 10 Ge 1-x Sn x P 2 S 12 “ in Chem. Mater. 2018, 30, pp. 1791-1798

[0051] Laidong Zhou et al.: “New Family of Argyrodite Thioantimonate Lithium Superionic Conductors” in J. Am. Chem. Soc. 2019, 141, pp. 19002-19013

[0051] Subin Song et al.: “Material Search for a Li 10 GeP 2 S 12-Type Solid Electrolyte in the Li-P-S-X (X = Br, I) System via Clarification of the Composition-Structure-Property Relationships“ in Chem Mater. 2022, 34, S. 8237-8247

[0051] Tomoyuki Tsujimura et al.: „Synthesis and characterization of low-temperature lithium-ion conductive phase of LiX(X = Cl, Br)-Li 3 PS 4 solid electrolytes“ in Solid State lonics 383, 2022, 115970, S. 1-8

[0051] Wo Dum Jung et al.: „Annealing-Free Thioantimonate Argyrodites with High Li-Ion Conductivity and Low Elastic Modulus“ in Adv. Funct. Mater. 2023, 33, 2211185, S. 1 bis 11

[0051]

Claims

[1] Sulfide-based solid electrolyte comprising or consisting of the general chemical formula (I): Li 6 M1 a M2 b S 5 X1 x X2 y Formula (I), where M1 is selected from the group consisting of P and Sb; M2 is selected from the group consisting of Si, Sn and W; a = 1.0 and 0.1 ≤ b ≤ 1.0; X1 and X2 are each independently selected from the group consisting of Cl, Br and I; where x + y = 2 and X1 ≠ X2. [2] Solid electrolyte according to claim 1, characterized by , that x in the range of 0.1 to 1.9 or 0.3 to 1.7, preferably in the range of 0.4 to 1.7 or 0.5 to 1.65 or 0.6 to 1.6, in particular in the range 0.75 to 1.5; and / or y in the range of 1.9 to 0.1 or 1.7 to 0.3, preferably in the range of 1.6 to 0.3 or 1.5 to 0.35 or 1.4 to 0.4, in particular in the range 1.25 to 0.

5. [3] Solid electrolyte according to claim 1 or 2, characterized by that x = 1 and y = 1. [4] Solid electrolyte according to one of claims 1 to 3, characterized by , that in the general chemical formula (I) applies: 0.1 ≤ b ≤ 0.95 or 0.15 ≤ b ≤ 0.95 or 0.2 ≤ b ≤ 0.9 or 0.25 ≤ b ≤ 0.85 or 0.25 ≤ b ≤ 0.8, in particular 0.3 ≤ b ≤ 0.75 or 0.3 ≤ b ≤ 0.7 or 0.35 ≤ b ≤ 0.7; and / or 1.2 ≤ a + b ≤ 2.0 or 1.25 ≤ a + b ≤ 2.0 or 1.3 ≤ a + b ≤ 2.0 or 1.35 ≤ a + b ≤ 1.9 or 1.4 ≤ a + b ≤ 1.9, in particular 1.4 ≤ a + b ≤ 1.85 or 1.4 ≤ a + b ≤ 1.

8. [5] A method for producing the sulfide-based solid electrolyte according to any one of claims 1 to 4, comprising the steps of: (a) providing the starting materials of the sulfide-based solid electrolyte, preferably in the form of sulfide and / or halide salts, (b) weighing the starting materials in the amounts according to the specified stoichiometry in the general formula (I) of the sulfide-based solid electrolyte according to claim 1; (c) first grinding the weighed quantities of starting materials in a ball mill at 300 to 500 rpm for more than 10 h; (d) second grinding of the mixture obtained in step (c) at 500 to 800 rpm in a ball mill for less than 10 h and (e) obtaining the sulfide-based solid electrolyte, wherein steps (b), (c) and (d) are carried out in an inert gas atmosphere with exclusion of moisture or in a vacuum with exclusion of moisture. [6] Method according to claim 5, characterized bythat the grinding in step (c) is carried out at 300 to 450 rpm, more preferably at 350 to 450 rpm, in particular at 400 rpm. [7] Method according to claim 5 or 6, characterized by that in step (c) the grinding in the ball mill is carried out for a duration in the range of 11 h to 18 h, preferably 11 h to 16 h, more preferably 11 h to 14 h or 11 h to 13 h or 11 h to 12 h, in particular 11 h. [8] Method according to one of claims 5 to 7, characterized by that the grinding in step (d) is carried out at 500 to 750 rpm, more preferably 500 to 700 rpm, even more preferably 550 to 700 rpm, in particular about 650 rpm. [9] Method according to one of claims 5 to 8, characterized by that in step (d) the grinding in the ball mill is carried out for a period in the range of 3 h to 9 h, preferably 4 h to 8 h, more preferably 5 h to 7 h, even more preferably 5 h to 6 h, in particular 5.5 h. [10] Method according to one of claims 5 to 9, characterized by that after step (b) and before step (c) mixing of the starting materials is carried out under an inert gas atmosphere and exclusion of moisture or in a vacuum with exclusion of moisture. [11] Use of the sulfide-based solid electrolyte according to any one of claims 1 to 4 in a solid-state battery cell. [12] A solid-state battery cell comprising the sulfide-based solid electrolyte according to any one of claims 1 to 4, wherein the solid-state battery cell is in particular a high power output cell. [13] Solid-state battery cell according to claim 12, characterized by that the solid-state battery cell has a cathode material layer, an anode material layer and an electrolyte layer arranged therebetween, wherein the sulfide-based solid electrolyte according to one of claims 1 to 3 is present in one, two or all three layers. [14] A solid-state battery cell according to claim 12 or 13 in the form of a primary battery or a secondary battery.