Sulfide solid electrolyte and preparation method therefor, solid electrolyte membrane, electrode sheet, solid-state battery and electric device

Abstract

The present application relates to a sulfide solid electrolyte and a preparation method therefor, a solid electrolyte membrane, an electrode sheet, a solid-state battery and an electric device. The sulfide solid electrolyte comprises an argyrodite-type crystal phase comprising an Li element, a P element, an S element, an X element and an M element, wherein the X element is a halogen, and the X element comprises one or more elements of Cl and Br; and the M element comprises at least one of Sb and Sn. The atomic number ratio of the X element to the P element in the argyrodite-type crystal phase is denoted as RX / P, and RX / P>1; and the atomic number ratio of the S element to the P element in the argyrodite-type crystal phase is denoted as RS / P, and RS / P>4.1.

Description

Sulfide solid electrolyte, preparation method thereof, solid electrolyte membrane, electrode sheet, solid-state battery and electric device

[0001] Related Applications

[0002] The present application claims priority to the Chinese patent application No. CN2024104372948, filed on April 11, 2024, and entitled “Sulfide solid electrolyte, preparation method thereof, solid electrolyte membrane, electrode sheet, solid-state battery and electric device”, the content of which is hereby incorporated by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the technical field of secondary batteries, further relates to the technical field of solid-state batteries, and more further relates to a sulfide solid electrolyte, a preparation method thereof, a solid electrolyte membrane, an electrode sheet, a solid-state battery and an electric device. BACKGROUND

[0004] The statements herein are provided only to enhance understanding of the present application and are not necessarily prior art.

[0005] Solid-state batteries introduce non-flammable solid electrolytes to replace organic electrolytes in conventional liquid secondary batteries, greatly improving the safety of the batteries. Among the numerous solid electrolyte materials, sulfide solid electrolytes have become the most practical and industrialized solid electrolyte material due to their ultra-high ionic conductivity and excellent mechanical properties. However, the stability of sulfide solid electrolytes is poor, and they easily react to release hydrogen sulfide toxic gas when exposed to moisture in the air, which seriously restricts the practical application of sulfide solid electrolytes. SUMMARY

[0006] According to various embodiments and various examples of the present application, the present application provides a sulfide solid electrolyte, a preparation method thereof, a solid electrolyte membrane, an electrode sheet, a solid-state battery and an electric device. The sulfide solid electrolyte significantly reduces the release of hydrogen sulfide of the sulfide electrolyte in a water-containing environment.

[0007] In a first aspect of the present application, a sulfide solid electrolyte is provided, comprising a argyrodite-type crystal phase;

[0008] The argyrodite-type crystal phase comprises Li element, P element, S element, X element and M element, the X element is halogen;

[0009] The X element comprises one or more elements of Cl and Br, and the M element comprises at least one of Sb element and Sn element;

[0010] The atomic number ratio of the X element to the P element in the argyrodite-type crystal phase is denoted as R X / P, the argyrodite-type crystal phase satisfies R X / P >1;

[0011] The atomic number ratio of S element and P element in the argyrodite-type crystal phase is denoted as R S / P , the argyrodite-type crystal phase satisfies R S / P >4.1.

[0012] The sulfide solid electrolyte includes an argyrodite-type crystal phase, by introducing M element, the content of phosphorus (P) element can be partially replaced, while controlling the atomic number ratio (R X / P ) of X element and P element to be greater than 1, the atomic number ratio (R S / P ) of S element and P element can be controlled to be greater than 4.1; based on the hard soft acid base theory (Hard Soft Acid Base-HSAB), compared with the bonding strength of hard acid (P) and soft base (S), soft acid (M element) and soft base (S) can form a stronger chemical bond, which is not easily destroyed by water molecules, which can significantly reduce the release amount of hydrogen sulfide gas of the sulfide solid electrolyte in a water-containing environment (such as air).

[0013] In some embodiments, 4.1 < R S / P <12.5; optionally, 4.5≤R S / P ≤12; further optionally, 4.5≤R S / P ≤10.25.

[0014] By controlling the atomic number ratio (R S / P ) of S element and P element in the above range, it is more beneficial to maintain good ionic conductivity while reducing the release amount of hydrogen sulfide gas of the sulfide solid electrolyte in a water-containing environment.

[0015] In some embodiments, the argyrodite-type crystal phase satisfies one or more of the following characteristics:

[0016] The atomic number ratio of M element and P element in the argyrodite-type crystal phase is denoted as R M / P , the argyrodite-type crystal phase satisfies 0 < R M / P ≤1.5, optionally, 0.1≤R M / P ≤1.5;

[0017] The M element is at least one of Sb element and Sn element;

[0018] The atomic number ratio of X element and P element in the argyrodite-type crystal phase is denoted as R X / P , the argyrodite-type crystal phase satisfies 1 < R X / P ≤4.75, optionally, 1.3≤R X / P≤ 4.7;

[0019] The X element is at least one of a Cl element and a Br element.

[0020] By controlling the atomic number ratio of the M element and the P element (R M / P ) in the aforementioned range, it is more advantageous to reduce the hydrogen sulfide gas release amount of the sulfide solid electrolyte in a water-containing environment while also maintaining a good ionic conductivity.

[0021] Both the Sb element and the Sn element can form a stronger chemical bond with the soft acid and the soft base (S), so that the chemical bond is not easily destroyed by water molecules, and the chemical stability of the material is significantly improved, which can significantly reduce the hydrogen sulfide gas release amount of the sulfide solid electrolyte in a water-containing environment.

[0022] In some embodiments, in the argyrodite-type crystal phase, the atomic number ratio of the Li element, the P element, the M element, the S element, and the X element is (6-x+z):(1-y-z):(y+z):(5-x):(1+x); wherein 0

[0023] In some embodiments, in the argyrodite-type crystal phase, the atomic number ratio of the Li element, the P element, the Sb element, the Sn element, the S element, and the Cl element is (6-x+z):(1-y-z):y:z:(5-x):(1+x); wherein 0

[0024] In some embodiments, the chemical formula of the argyrodite-type crystal phase is Li 6-x+z P 1-y-z M y+z S 5-x X 1+x ;

[0025] Optionally, the chemical formula of the argyrodite-type crystal phase is Li 6-x+z P 1-y-z Sb y Sn z S 5-x Cl 1+x .

[0026] By controlling the atomic number ratio of the Li element, the P element, the M element, the S element, and the X element in the argyrodite-type crystal phase in the aforementioned range, it is more advantageous to reduce the hydrogen sulfide gas release amount of the sulfide solid electrolyte in a water-containing environment while also maintaining a good ionic conductivity.

[0027] In some embodiments, the argyrodite-type crystal phase satisfies one or more of the following characteristics:

[0028] x satisfies 0.2≤x≤0.9;

[0029] y satisfies 0.05≤y≤0.2;

[0030] z satisfies 0.05≤z≤0.4;

[0031] y and z satisfy 0.1≤(y+z)≤0.6.

[0032] By controlling one or more of x, y, and z within the aforementioned ranges, it is more advantageous to reduce the amount of hydrogen sulfide gas released by the sulfide solid electrolyte in an aqueous environment while also maintaining a good ionic conductivity.

[0033] By controlling y within the aforementioned range, it is possible to reduce the content of P element while also achieving sufficient solid solution of Sb element in the crystal structure, which is advantageous for reducing impurities and achieving a good ionic conductivity.

[0034] By controlling z within the aforementioned range, it is possible to reduce the content of P element while also achieving sufficient solid solution of Sn element in the crystal structure, which is advantageous for reducing impurities and achieving a good ionic conductivity.

[0035] In some embodiments, the argyrodite-type crystal phase satisfies one or more of the following characteristics:

[0036] In the argyrodite-type crystal phase, the atomic ratio of Li element to P element is denoted as R Li / P , which satisfies 5.1<R Li / P <16>Optionally, 6.5≤R Li / P ≤13.7;

[0037] In the argyrodite-type crystal phase, the atomic ratio of Cl element to P element is denoted as R Cl / P , which satisfies 1<R Cl / P ≤4.75, optionally, 1.3≤R Cl / P ≤4.7;

[0038] In the argyrodite-type crystal phase, the atomic ratio of Sb element to P element is denoted as R Sb / P , and the atomic ratio of Sn element to P element is denoted as R Sn / P , which satisfies 0<(R Sb / P +R Sn / P )≤1.5, optionally, 0.1≤(R Sb / P +R Sn / P )≤1.5.

[0039] by controlling one or more of the atomic number ratio of Li element to P element (R Li / P ), the atomic number ratio of Cl element to P element (R Cl / P ), and the atomic number ratio of the sum of Sb element and Sn element to P element (R Sb / P + R Sn / P ) within the aforementioned ranges, the amount of hydrogen sulfide gas released from the sulfide solid electrolyte in a water-containing environment can be reduced while maintaining a good ionic conductivity.

[0040] In some embodiments, in the argyrodite-type crystal phase, the atomic number ratio of Sb element to Sn element is denoted as R Sb / Sn , and satisfies 0≤R Sb / Sn ≤1, and can be 0.5≤R Sb / Sn ≤1.

[0041] By controlling the atomic number ratio of Sb element to Sn element (R Sb / Sn ) within the aforementioned ranges, the content of P element can be reduced while achieving sufficient solid solution of Sb element and Sn element, which is beneficial to reducing the amount of hydrogen sulfide gas released from the sulfide solid electrolyte in a water-containing environment while maintaining a good ionic conductivity.

[0042] In some embodiments, the argyrodite-type crystal phase has any one of the following chemical formulas: Li 5.5 P 0.9 Sb 0.1 S 4.5 Cl 1.5 , Li 5.6 P 0.7 Sn 0.3 S 4.3 Cl 1.7 , and Li 5.2 P 1.8 Sb 0.1 Sn 0.1 S 4.1 Cl 1.9 .

[0043] By providing one or more of the aforementioned argyrodite-type crystal phases in the sulfide solid electrolyte, the amount of hydrogen sulfide gas released and the ionic conductivity can be both reduced.

[0044] In some embodiments, the sulfide solid electrolyte has a characteristic peak in the 2θ (°) diffraction angle in the X-ray diffraction pattern of the sulfide solid electrolyte.

[0045] In some embodiments, the sulfide solid electrolyte satisfies at least one of the following characteristics:

[0046] the sulfide solid electrolyte has peaks at 2-theta (°) diffraction angles of 15.5±0.2°, 18.1±0.2°, 25.6±0.2°, 30.1±0.2°, 31.4±0.2°, 39.8±0.2°, 45.1±0.2°, 47.9±0.2°, and 52.5±0.2° in an X-ray diffraction pattern thereof;

[0047] The X-ray diffraction pattern of the sulfide solid electrolyte is obtained by using Cu Kα rays.

[0048] The X-ray diffraction pattern of the sulfide solid electrolyte is obtained by a powder X-ray diffraction test.

[0049] The chemical composition in the sulfide solid electrolyte can be confirmed by X-ray diffraction (XRD) detection.

[0050] In a second aspect of the present application, a preparation method of a sulfide solid electrolyte is provided, which can be used to prepare the sulfide solid electrolyte of the first aspect of the present application.

[0051] In some embodiments, the preparation method of the sulfide solid electrolyte comprises the following steps:

[0052] A precursor mixture comprising Li2S, P2S5, LiX, a M source, and elemental sulfur is provided according to a desired stoichiometric ratio of raw materials; wherein X is a halogen, X includes one or more of Cl and Br; the M source is a raw material providing a M element, the M element includes at least one of an Sb element and a Sn element; when the sulfide solid electrolyte contains an Sb element, the precursor mixture further includes Sb2S3; when the sulfide solid electrolyte contains a Sn element, the precursor mixture includes SnS2;

[0053] The precursor mixture is sintered in an inert atmosphere to prepare a sulfide solid electrolyte comprising a argyrodite-type crystal phase; the atomic number ratio of X element to P element in the argyrodite-type crystal phase is denoted as R X / P The atomic number ratio of S element to P element in the argyrodite-type crystal phase is denoted as R S / P The argyrodite-type crystal phase satisfies R X / P > 1 and R S / P > 4.1.

[0054] In some embodiments, the preparation method of the sulfide solid electrolyte satisfies one or more of the following features:

[0055] The weight ratio of the elemental sulfur to the precursor mixture is 3.9wt% to 4.1wt%;

[0056] The inert atmosphere is an argon atmosphere;

[0057] The sintering temperature is 450-530°C;

[0058] The sulfide solid electrolyte prepared is the sulfide solid electrolyte according to the first aspect of the application.

[0059] The sulfide solid electrolyte according to the first aspect of the application can be obtained by sintering a corresponding precursor mixture in the presence of excess elemental sulfur at a certain sintering temperature.

[0060] In the third aspect of the application, a solid electrolyte membrane is provided, which comprises at least one of the sulfide solid electrolyte according to the first aspect of the application and the sulfide solid electrolyte prepared by the preparation method according to the second aspect of the application.

[0061] For the solid electrolyte membrane provided with the aforementioned sulfide solid electrolyte, the sulfide solid electrolyte has high stability in a water-containing environment (such as air) and low hydrogen sulfide release, and the material has good chemical stability, so that the sulfide solid electrolyte in the solid electrolyte membrane has good quality stability, which is conducive to making the corresponding solid-state battery fully exert the high ionic conductivity advantage of the sulfide solid electrolyte and having good cycle performance.

[0062] In the fourth aspect of the application, an electrode tab is provided, which comprises an electrode active material layer comprising an electrode active substance and at least one of the sulfide solid electrolyte according to the first aspect of the application and the sulfide solid electrolyte prepared by the preparation method according to the second aspect of the application.

[0063] In some embodiments, the electrode tab is a positive electrode tab, the electrode active material layer is referred to as a positive electrode active material layer, and the electrode active substance is referred to as a positive electrode active substance;

[0064] Alternatively, the electrode tab is a negative electrode tab, the electrode active material layer is referred to as a negative electrode active material layer, and the electrode active substance is referred to as a negative electrode active substance.

[0065] For the electrode tab provided with the aforementioned sulfide solid electrolyte, the sulfide solid electrolyte has high stability in a water-containing environment (such as air) and low hydrogen sulfide release, and the material has good chemical stability, so that the electrode tab has good quality stability, and the solid-state battery assembled using the electrode tab can fully exert the high ionic conductivity advantage of the sulfide solid electrolyte and have good cycle performance.

[0066] The electrode tab can be a positive electrode tab or a negative electrode tab.

[0067] In a fifth aspect of the present application, a solid-state battery is provided, which comprises at least one of the sulfide solid electrolyte of the first aspect of the present application, the sulfide solid electrolyte prepared by the preparation method of the second aspect of the present application, the solid electrolyte film of the third aspect of the present application, and the electrode tab of the fourth aspect of the present application.

[0068] In some embodiments, the solid-state battery is a sulfide all-solid-state battery.

[0069] For the solid-state battery provided with the aforementioned sulfide solid electrolyte, the sulfide solid electrolyte can be provided at one or more of the positive electrode layer, the negative electrode layer, and the solid electrolyte layer.

[0070] In a sixth aspect of the present application, a power utilization device is provided, which comprises at least one of the sulfide solid electrolyte of the first aspect of the present application, the sulfide solid electrolyte prepared by the preparation method of the second aspect of the present application, the solid electrolyte film of the third aspect of the present application, the electrode tab of the fourth aspect of the present application, and the solid-state battery of the fifth aspect of the present application.

[0071] The details of one or more embodiments or examples of the present application are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the present application will be apparent from the description, drawings, and claims. BRIEF DESCRIPTION OF DRAWINGS

[0072] In order to better describe and illustrate the embodiments, examples or examples provided by the present application, one or more drawings can be referred to. Additional details or examples used to describe the drawings should not be considered as limiting the scope of any one of the disclosed applications, the presently described embodiments, examples or examples, and the best mode of these applications currently understood. It should be noted that the drawings are all drawn in a simplified form, only for the convenience, clarity of the description of the present application. The various sizes of each component shown in the drawings are arbitrarily shown, which can be accurate or not drawn according to the actual proportion. For example, in order to make the drawing clearer, the size of some components in the drawing is appropriately exaggerated. Unless otherwise specified, the components in the drawing are not drawn to scale. The drawings of the present application do not limit the size of each component. Moreover, the same reference numerals are used to represent the same components in all the drawings. In the drawings:

[0073] Figure 1 is a schematic view of the structure of a solid-state battery cell according to an embodiment of the present application, which comprises a positive electrode layer, a solid electrolyte layer and a negative electrode layer stacked in sequence.

[0074] Figure 2 is a schematic view of a solid-state battery monomer according to an embodiment of the present application.

[0075] Figure 3 is an exploded view of the solid-state battery monomer shown in Figure 2 according to an embodiment of the present application.

[0076] FIG. 4 is a schematic view of a battery module according to an embodiment of the present application.

[0077] FIG. 5 is a schematic view of a battery pack according to an embodiment of the present application.

[0078] FIG. 6 is an exploded view of the battery pack according to an embodiment of the present application shown in FIG. 5.

[0079] FIG. 7 is a schematic view of an electric device using a solid-state battery as a power source according to an embodiment of the present application.

[0080] FIG. 8 is an X-ray diffraction (XRD) pattern of the sulfide solid electrolyte prepared in Preparation Example 8 and Comparative Example 3 of the present application, in which the horizontal axis represents 2θ (degree) and the vertical axis represents intensity.

[0081] BRIEF DESCRIPTION OF DRAWINGS 100: solid electrolyte layer; 200: positive electrode layer; 300: negative electrode layer; 1: battery pack; 2: upper case; 3: lower case; 4: battery module; 5: solid-state battery cell; 51: housing; 52: solid-state battery core; 53: cover plate; 6: electric device. DETAILED DESCRIPTION

[0082] Hereinafter, some embodiments of a sulfide solid electrolyte and a method for preparing the same, a solid electrolyte film, an electrode sheet, a solid-state battery, an electric device, and the like according to the present application are described in detail with appropriate reference to the accompanying drawings. However, there can be cases where unnecessary detailed descriptions are omitted. For example, there can be cases where detailed descriptions of matters well known in the art, repetitive descriptions of substantially identical structures are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate understanding by those skilled in the art. In addition, the accompanying drawings and the following description are provided so that those skilled in the art can fully understand the present application, and are not intended to limit the subject matter recited in the claims.

[0083] The ranges disclosed herein can be limited by both a lower limit and an upper limit, to define a range by selecting a lower limit and an upper limit, the selected lower limit and upper limit define the boundaries of the particular range. Ranges defined by such limits can be either inclusive or exclusive of the end values, either end value can be included or excluded independently, and can be combined in any manner, i.e., any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a particular parameter, it is understood that ranges of 60-110 and 80-120 are also contemplated. In addition, if minimum range values of 1 and 2 are listed, and if maximum range values of 3, 4, and 5 are also listed, then the following ranges are all contemplated: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise indicated, a numerical range "a-b" indicates a shorthand way of describing each and every intervening real number, integer or combination thereof between the upper and lower limits of that range, in which "a" and "b" are both real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed herein, "0-5" is merely a shorthand way of describing those numerical combinations. In addition, when a parameter is stated to be an integer ≥ 2, it is equivalent to listing the parameter as, for example, integer 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc. For example, when a parameter is stated to be an integer selected from "2-10", it is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0084] In this application, unless otherwise specified, "about" means within a reasonable range, the fluctuation range can vary depending on the type and value of the number. For example, it can be allowed within the range of ±10%, ±5%, ±2%, ±1%, etc. For example, taking "about 20°C" and its approximation ±1°C as an example, the approximation values of 19°C, 19.5°C, etc. within the approximation range indicated by "about 20°C" should also be included in the range indicated by "about 20°C".

[0085] In this application, unless otherwise specified, "a plurality of", "a plurality of", "a plurality of", "several", etc. means more than 2 or equal to 2 in quantity. For example, "one or more" means one or ≥(greater than or equal to) two. It can be understood that when referring to "any number of" items, it means any suitable combination of a plurality of items, i.e., in a manner that does not conflict and can implement the present application.

[0086] If not specifically stated, all embodiments and optional embodiments of the present application can be combined to form new technical solutions.

[0087] Reference to "an embodiment" herein means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another. As used herein, the term "implementation" is understood similarly.

[0088] Those skilled in the art understand that the order in which steps are written in the methods of the various implementations or embodiments does not imply a strict execution order and does not constitute any limitation on the implementation process, and the detailed execution order of each step should be determined by its function and possible internal logic. If not specifically stated, all steps of the application can be performed sequentially or randomly, and can be preferably performed sequentially. For example, method M includes steps (a) and (b), which means that the method can include steps (a) and (b) performed sequentially, or steps (b) and (a) performed sequentially. For example, method M also includes step (c), which means that step (c) can be added to method M in any order, for example, method M can include steps (a), (b) and (c), or steps (a), (c) and (b), or steps (c), (a) and (b), etc.

[0089] In this application, the open technical features or technical solutions described with the words "containing", "including", "comprising" and the like, if not otherwise stated, do not exclude additional members from the listed members, which can be regarded as providing both a closed feature or solution composed of the listed members, and an open feature or solution including additional members in addition to the listed members. For example, A includes a1, a2 and a3, if not otherwise stated, it can also include other members, or it can not include additional members, which can be regarded as providing the feature or solution that "A is composed of a1, a2 and a3" or "A is selected from a1, a2 and a3", and also providing the feature or solution that "A includes a1, a2 and a3, and also includes other members".

[0090] In this application, A (such as B) means that B is a non-limiting example of A, and A can be understood as not limited to B, if not otherwise stated.

[0091] In this application, "optionally", "optional" and "optional" mean optional, i.e. selected from "yes" or "no" two parallel solutions. If there are multiple "optional" in a technical solution, if not specifically stated, and there is no contradictory relationship or mutual restriction. If not otherwise stated, "optionally includes", "optionally contains" and the like are described in this application, for example, "optionally includes" means "may include or not include".

[0092] In the present application, "and / or" corresponds to any one of two or more related listed items, and also includes any and all combinations of the related listed items, where any and all combinations include any two related listed items, any more related listed items, or all related listed items. For example, "A and / or B" represents a group consisting of A, B, and a combination of A and B. Where "including A and / or B" can mean "including A, including B, and including A and B", and can also mean "including A, including B, or including A and B", which can be properly understood according to the sentence.

[0093] As used herein, "combinations thereof", "any combination thereof", "any combination manner thereof", and the like include all suitable combination manners of any two or more of the listed items.

[0094] As used herein, "suitable combination manner", "suitable manner", "any suitable manner", and the like, "suitable" is subject to the implementation of the technical solutions of the present application.

[0095] As used herein, "preferred", "better", "better", "as appropriate", "better", "better" are only to describe the implementation mode or embodiment with better effect, and it should be understood that it does not constitute a limitation on the protection scope of the present application. If there are multiple "preferred" in a technical solution, if there is no special description, and there is no contradictory relationship or mutual restriction, each "preferred" is independent.

[0096] In the present application, "further", "more further", "in particular", "for example", "such as", "example", "for example" are used for description purposes, indicating differences in content, but should not be understood as limiting the scope of protection of the present application.

[0097] In the present application, "first aspect", "second aspect", "third aspect", "fourth aspect", "fifth aspect", "sixth aspect", and the like, the terms "first", "second", "third", "fourth", "fifth", "sixth" are only for description purposes, and cannot be understood as indicating or implying relative importance or quantity, nor can it be understood as implying the importance or quantity of the indicated technical features. Moreover, "first", "second", "third", "fourth", "fifth", "sixth" only serve the purpose of non-exhaustive enumeration description, and it should be understood that it does not constitute a closed limitation on the quantity.

[0098] In the present application, unless specifically stated and limited otherwise, a first feature is "on" or "under" a second feature can mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. In the present application, unless specifically stated and limited otherwise, a first feature is "on" or "under" a second feature can mean a horizontal height reciprocal position relationship, or can only mean an attachment relationship without limiting the horizontal height reciprocal position relationship.

[0099] In the present application, the term "room temperature" generally refers to 4°C to 35°C, and can refer to 20°C ± 5°C. In some embodiments or examples of the present application, room temperature refers to 20°C to 30°C.

[0100] In the present application, the units related to the data range, if only the right end point is followed by a unit, it means that the units of the left end point and the right end point are the same. For example, 3-5h or 3-5h means that the units of the left end point "3" and the right end point "5" are both h (hours), and both have the same meaning as 3h-5h. In addition, similar descriptions of other parameters such as temperature, size, etc. are also understood in the same way.

[0101] The weight or mass of the related components mentioned in the embodiments or examples of the present application can not only refer to the content of each component, but also represent the proportional relationship between the weight or mass of each component, so as long as the content of the related components in the embodiments or examples of the present application is enlarged or reduced in proportion, it is within the scope described in the present application. Further, the mass involved in the embodiments or examples of the present application can be micrograms (μg), milligrams (mg), grams (g), kilograms (kg), etc. Mass ratio is equal to the corresponding weight ratio, for example, the mass of substance A is m1, the weight is W1, the mass of substance B is m2, and the weight is W2. The mass ratio m1 / m2 is equal to the corresponding weight ratio W1 / W2 in numerical value.

[0102] In the present application, unless otherwise specified, wt% means weight percentage by weight, which is equal in numerical value to the corresponding mass percentage by mass. In the present application, for weight percentage, "0" has the same meaning as "0wt%" and can be used interchangeably.

[0103] In the present application, unless otherwise specified, nm represents nanometer, μm represents micrometer, S / cm represents siemens per centimeter, V represents volt, kV represents kilovolt, mA represents milliamperes, Hz represents hertz, mPa·S represents millipascal·second, mg / cm 2 represents milligrams per square centimeter, g / cm 2 represents grams per square centimeter, g / cm 3 represents grams per cubic centimeter, and °C represents Celsius.

[0104] In the present application, “greater than or equal to”, “greater than or equal to” and “≥” have the same meaning and can be used interchangeably; “less than or equal to”, “less than or equal to” and “≤” have the same meaning and can be used interchangeably; “greater than” can be equivalent to “>”, and “less than” can be equivalent to “<”. In the present application, unless otherwise specified, “greater than or equal to” and “≥” can be considered to provide both “greater than” and “equal to” options. In the present application, unless otherwise specified, “less than or equal to” and “≤” can be considered to provide both “less than” and “equal to” options.

[0105] In the present application, exemplary descriptions involving “in some embodiments (or examples)”, “in an embodiment (or example)” and the like can cover, but are not limited to, the following meanings: these options can be combined with other options in a suitable manner to form new technical solutions.

[0106] In the present application, unless otherwise specified, the “solid-state battery” provided in the present application refers to a battery in which the electrolyte in the battery comprises a solid electrolyte; generally, a solid-state battery comprises a positive electrode layer, a solid electrolyte layer and a negative electrode layer. During the charging and discharging process of the battery, active ions are embedded and extracted between the positive electrode layer and the negative electrode layer. The solid electrolyte layer plays a role in conducting ions between the positive electrode layer and the negative electrode layer, and can also isolate the positive electrode layer from the negative electrode layer to prevent short circuiting of the positive and negative electrodes, therefore, the solid-state battery can not be provided with a separator film in a traditional lithium-ion battery. The introduction of non-flammable solid electrolyte in the solid-state battery instead of organic electrolyte in the traditional liquid lithium-ion battery greatly improves the safety of the battery. In addition to improving safety, solid-state batteries can also better adapt to high-energy-density positive and negative electrode materials, and reduce system weight, which is conducive to improving energy density.

[0107] In the present application, unless otherwise specified, “solid electrolyte” refers to an electrolyte material or electrolyte substance that exists in a solid state during the storage and preparation of solid-state batteries and components constituting solid-state batteries, and during the working process of solid-state batteries. It can be understood that the solid electrolyte exists in a solid state at room temperature, including but not limited to.

[0108] In the present application, unless otherwise specified, the electrode layer can be a positive electrode layer or a negative electrode layer, and the electrode layer comprises an electrode active material. The electrode active material can be a positive electrode active material or a negative electrode active material. The electrode active material can be in the form of a particle itself or can be contained in an electrode active particle. The electrode active particle can be a positive electrode active particle or a negative electrode active particle. The “electrode active material” in the electrode layer refers to a material capable of reversibly intercalating and deintercalating active ions. Unless otherwise specified, the “negative electrode active material” refers to a material capable of reversibly intercalating and deintercalating active ions used in the negative electrode layer; the “positive electrode active material” refers to a material capable of reversibly deintercalating and intercalating active ions used in the positive electrode layer. During charging of the solid-state battery, active ions are deintercalated from the positive electrode, intercalate the negative electrode through the solid electrolyte layer; and during discharging of the solid-state battery, active ions are deintercalated from the negative electrode and intercalate the positive electrode. The active ion is not particularly limited, and non-limitingly, the active ion can be a lithium ion, in which case a lithium ion solid-state battery corresponds.

[0109] In the present application, the “electrode active particle” refers to a particle containing an electrode active material.

[0110] In the present application, “electrode active material”, “electrode active substance”, “active material” and “active substance” have the same meaning and can be used interchangeably; “positive electrode active material” and “positive electrode active substance” have the same meaning and can be used interchangeably; “negative electrode active material” and “negative electrode active substance” have the same meaning and can be used interchangeably. “Positive electrode active material” and “positive electrode active substance” have the same meaning and can be used interchangeably; “negative electrode active material” and “negative electrode active substance” have the same meaning and can be used interchangeably.

[0111] In the present application, unless otherwise specified, the “electrode active material layer” comprises at least one of the positive electrode active material layer in the positive electrode layer and the negative electrode active material layer in the negative electrode layer, and according to the specific circumstances, the electrode active material layer can refer to the positive electrode active material layer or the negative electrode active material layer. It can be understood that the positive electrode active material layer contains a positive electrode active material, and the negative electrode active material layer contains a negative electrode active material. In the present application, the “electrode active material layer” can also be abbreviated as “active material layer”.

[0112] In the present application, unless otherwise specified, the positive electrode layer comprises at least a positive electrode active material layer.

[0113] In the present application, unless otherwise specified, the positive electrode active material layer comprises at least positive electrode active particles, and usually further comprises positive electrode electrolyte particles.

[0114] In the present application, unless otherwise specified, the “positive electrode active particle” refers to a particle containing a positive electrode active material, which has the ability to reversibly deintercalate and intercalate active ions.

[0115] In the present application, unless otherwise specified, "positive electrode electrolyte particles" have the same meaning as "positive electrode solid electrolyte" and "positive electrode electrolyte material", and can be used interchangeably, referring to a solid electrolyte that can be used in a positive electrode film or positive electrode layer. The positive electrode electrolyte particles can enhance the ion conduction ability of the positive electrode film or positive electrode layer, reduce the interface impedance, and promote the charge transfer efficiency of the positive electrode active material to the outside and the full release of its capacity.

[0116] In the present application, unless otherwise specified, the negative electrode layer at least includes a negative electrode active material layer.

[0117] In the present application, unless otherwise specified, the negative electrode active material layer at least includes negative electrode active particles, and can or can not include negative electrode electrolyte particles.

[0118] In the present application, unless otherwise specified, "negative electrode active particles" refer to particles containing negative electrode active materials, which have the ability to reversibly intercalate and deintercalate active ions.

[0119] In the present application, unless otherwise specified, "negative electrode electrolyte particles" have the same meaning as "negative electrode solid electrolyte" and "negative electrode electrolyte material", and can be used interchangeably, referring to a solid electrolyte that can be used in a negative electrode film or negative electrode layer. The negative electrode electrolyte particles can enhance the ion conduction ability of the negative electrode film or negative electrode layer, reduce the interface impedance, and promote the charge transfer efficiency of the negative electrode active material to the outside and the full release of its capacity.

[0120] In solid-state batteries, interface contact and interface stability are one of the pain points that limit the performance of the batteries. Poor interface contact can affect the cycle performance of the batteries. Due to the "solid-solid contact" characteristics in solid-state batteries, the contact between the particles in the electrode layer includes a large number of point contacts, which cannot completely wet the electrode active material like the electrolyte in liquid batteries. This causes insufficient ion transmission at the interface in the electrode layer, and further leads to unsatisfactory performance of the solid-state batteries. By doping solid electrolyte materials into the electrode layer, the ion conduction ability of the electrode layer can be theoretically enhanced, the charge transfer efficiency of the electrode active material to the outside and the full release of its capacity can be promoted, and the impedance can be reduced. Among the many solid electrolyte materials, sulfide solid electrolyte has ultra-high ion conductivity (about 10 -3 ~ 10 -2 S / cm) and excellent mechanical properties, such as good flexibility, making it have excellent ion conduction ability and good deformation ability, and is a solid electrolyte material with the most practical and industrialization prospects. However, the stability of sulfide solid electrolyte is poor, and it can easily react with moisture in the air to release hydrogen sulfide toxic gas, which can also cause a decrease in ion conductivity. In addition, hydrogen sulfide gas is also flammable and explosive, which seriously restricts the practical application of sulfide solid electrolyte.

[0121] According to various embodiments and various examples of the present application, the present application at least provides a sulfide solid electrolyte and a preparation method thereof, a solid electrolyte film, an electrode sheet, a solid-state battery, and an electric device. The present application can also provide a positive electrode film, a negative electrode film, and a secondary battery. The sulfide solid electrolyte significantly reduces the amount of hydrogen sulfide released by the sulfide electrolyte in a water-containing environment.

[0122] In a first aspect of the present application, a sulfide solid electrolyte is provided, which includes a argyrodite-type crystal phase.

[0123] In some embodiments, the argyrodite-type crystal phase includes Li elements, P elements, S elements, X elements, and M elements, the X elements being halogens; wherein the X elements include one or more of Cl and Br, and the M elements include at least one of Sb elements and Sn elements.

[0124] In some embodiments, the atomic number ratio of the X elements to the P elements in the argyrodite-type crystal phase is denoted as R X / P , and the argyrodite-type crystal phase satisfies R X / P > 1.

[0125] In some embodiments, the atomic number ratio of the S elements to the P elements in the argyrodite-type crystal phase is denoted as R S / P , and the argyrodite-type crystal phase satisfies R S / P > 4.1.

[0126] In some embodiments, a sulfide solid electrolyte is provided, which includes an argyrodite-type crystal phase;

[0127] The argyrodite-type crystal phase includes Li elements, P elements, S elements, X elements, and M elements, the X elements being halogens;

[0128] The X elements include one or more of Cl and Br, and the M elements include at least one of Sb elements and Sn elements.

[0129] The atomic number ratio of the X elements to the P elements in the argyrodite-type crystal phase is denoted as R X / P , and the argyrodite-type crystal phase satisfies R X / P > 1.

[0130] The atomic number ratio of the S elements to the P elements in the argyrodite-type crystal phase is denoted as R S / P , and the argyrodite-type crystal phase satisfies R S / P > 4.1.

[0131] In the present application, unless otherwise specified, "sulfide electrolyte" and "sulfide solid electrolyte" have the same meaning and can be used interchangeably, and refer to a solid electrolyte in the form of a sulfide, and the sulfide electrolyte includes sulfur (S) in the form of a sulfide. The "sulfide electrolyte" referred to in the embodiments or examples of the present application can be included in any one of a solid electrolyte layer, a positive electrode layer, and a negative electrode layer, can be included in an electrolyte material of a solid electrolyte layer, can be included in a positive electrode electrolyte particle, and can be included in a negative electrode electrolyte particle.

[0132] In some embodiments of the present application, "M element" can be used to replace phosphorus (P) in a argyrodite-type crystal phase.

[0133] In the present application, unless otherwise specified, "X element" is a halogen and can include one or more of Cl and Br, and can be at least one of Cl and Br.

[0134] In the present application, unless otherwise specified, "argyrodite-type crystal phase" refers to a crystal structure that is the same as or similar to that of a sulfide solid electrolyte Li6PS5Cl, and belongs to a cubic system, and the argyrodite-type crystal phase corresponds to an argyrodite-type sulfide solid electrolyte; and "argyrodite-type sulfide solid electrolyte" refers to a sulfide solid electrolyte having a crystal structure that is the same as or similar to that of a sulfide solid electrolyte Li6PS5Cl.

[0135] In the sulfide solid electrolyte provided in the present application, in the crystal structure of the argyrodite-type crystal phase, the P element is partially replaced by the M element, and the atomic number ratio (R X / P ) of the X element to the P element is greater than 1, and the atomic number ratio (R S / P ) of the S element to the P element can be controlled to be R S / P > 4.1.

[0136] In the present application, unless otherwise specified, "atomic number ratio" refers to the number ratio of a specified element or atom, and can be measured in moles, in which case it corresponds to "atomic mole ratio".

[0137] In the present application, unless otherwise specified, whether the sulfide solid electrolyte includes argyrodite-type crystal phase can be determined according to X-ray diffraction (XRD) pattern. In the present application, unless otherwise specified, the X-ray diffraction pattern of the sulfide solid electrolyte is obtained by using Cu Kα ray with powder sample. Generally, the 2θ(°) scanning range includes at least 10°-50° (the scanning range can include 10°-80°), and the 2θ(°) scanning speed can be 0.02° / second. In some embodiments, the XRD testing instrument and parameters are as follows: Bruker-D8 advance, using Cu target Kα1 ray, wavelength λ is 0.15406 nm, X-ray tube is controlled at 40 kV and 40 mA, 2θ(°) scanning range is 10°-80°, and 2θ(°) scanning speed is 0.02° / second. Whether the sulfide solid electrolyte to be tested includes argyrodite-type crystal phase can be confirmed by the skilled person in the art according to the comparison analysis with the XRD standard spectrum of Li6PS5Cl. In some embodiments, the X-ray diffraction pattern of the sulfide solid electrolyte has peaks near 15.5°, 18.1°, 25.6°, 30.1°, 31.4°, 39.8°, 45.1°, 47.9° and 52.5° of 2θ(°) diffraction angle in the following group. Due to the difference of measurement instruments and measurement conditions and other measurement factors, the position of a certain peak or some peaks in the actually obtained X-ray diffraction pattern can be slightly shifted (for example, ±δ°), but it can be understood that the skilled person in the art can identify whether the X-ray diffraction pattern including slightly different characteristic peaks constitutes argyrodite-type crystal phase in essence. Unless otherwise specified, “±δ°” only represents the error of the peak value in the diffraction angle position, and is irrelevant to the peak shape and peak width of the peak. Numerically, regarding the aforementioned peak position shift ±δ°, δ can be 0.4, 0.3, 0.2, 0.1 and the like according to the measurement conditions, for example, in some embodiments, δ=0.2.

[0138] In the present application, unless otherwise specified, the element types and the atomic number ratio of each element in the sulfide solid electrolyte can be determined according to element analysis methods such as inductively coupled plasma spectrometer (ICP method), so as to determine the chemical formula.

[0139] The sulfide solid electrolyte includes argyrodite-type crystal phase, and the P element can be partially replaced by introducing M element, so as to reduce the content of phosphorus (P) element, and control the atomic number ratio (R X / P ) of X element and P element to be greater than 1, so as to realize the control of the atomic number ratio (R S / P) is greater than 4.1; based on the Hard Soft Acid Base (HSAB) theory, compared to the bonding strength of a hard acid (P) and a soft base (S), a soft acid (M element) and a soft base (S) can form a stronger chemical bond, which is not easily broken by water molecules, which can significantly reduce the release of hydrogen sulfide gas from the sulfide solid electrolyte in a water-containing environment (such as air).

[0140] In some embodiments, R S / P may be denoted as the ratio of N2 and N1 (N2 / N1), where N2 is a suitable positive number less than 50, and N1 is a suitable positive number less than 10. In some embodiments, 41≤N2<50, and N2 can also be any of the following values: 41, 42, 43, 44, 45, 46, 47, 48, 49, 49.5, etc. In some embodiments, 4≤N1<10, and N1 can also be any of the following values: 4, 4.5, 5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, etc. For R S / P , N2 and N1 can be any combination. In some embodiments, R S / P may be selected from a suitable interval of any two N2 / N1 values.

[0141] In some embodiments, 4.1<R S / P <12.5; optionally, 4.5≤R S / P ≤12; further optionally, 4.5≤R S / P ≤10.25. Without limitation, R S / P may also be any of the following values, greater than 4.1 and less than or equal to any of the following values, greater than or equal to any of the following values and less than 12.5, or selected from an interval of any two of the following values: 4.2, 4.3, 4.4, 4.5, 4.6, 43 / 9, 4.75, 45 / 9.5, 4.8, 41 / 8.5, 5, 41 / 8, 5.2, 43 / 8, 5.4, 5.5, 5.6, 45 / 8 (i.e. 5.625), 5.75, 5.8, 41 / 7, 6, 43 / 7, 6.25, 6.4, 6.5, 6.6, 6.8, 7, 43 / 6, 7.5, 8, 8.5, 9, 9.5, 10, 10.2, 10.25 (equal to 41 / 4), 10.5, 11, 11.5, 12, etc.

[0142] In this application, when referring to a value, fractions are allowed, for example, "41 / 4" means four forty-firsts.

[0143] By adjusting the ratio of the number of atoms of S element and P element (R S / P) control in the foregoing range, while reducing the amount of hydrogen sulfide gas released by the sulfide solid electrolyte in the aqueous environment, it is also more conducive to maintaining a better ionic conductivity.

[0144] In the present application, in the argyrodite-type crystal phase, the atomic number ratio of the M element and the P element can be denoted as R M / P .

[0145] In some embodiments, R M / P may be denoted as the ratio of N3 and N1 (N3 / N1), where N3 is a suitable value greater than 0, and N1 can refer to the definition above. In some embodiments, 0 < N3 ≤ 6, N3 can also be any of the following values: 0.5, 1, 1.5, 1 / 8.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, etc. For R M / P , N3 and N1 can be any combination. In some embodiments, R M / P may be selected from a suitable interval consisting of any two N3 / N1 values.

[0146] In some embodiments, N3+N1 = 10.

[0147] In some embodiments, 0 < R M / P ≤ 1.5, optionally, 0.1 ≤ R M / P ≤ 1.5. Without limitation, R M / P may also be any of the following values, greater than 0 and less than or equal to any of the following values, or selected from an interval consisting of any two of the following values: 0.05, 0.053, 5 / 9.5, 0.1, 1 / 9, 0.125, 0.15, 0.2, 0.25 (equal to 2 / 8), 0.3, 0.35, 0.4, 0.425, 3 / 7, 0.45, 0.5, 0.6, 0.625, 0.64, 0.65, 4 / 6, 0.7, 0.75, 0.8, 0.825, 0.9, 0.95, 1, 1.05, 1.1, 1.2, 1.25, 1.3, 1.4, 1.45, 1.5 (equal to 6 / 4), etc.

[0148] In the present application, in the argyrodite-type crystal phase, the atomic number ratio of the X element and the P element can be denoted as R X / P .

[0149] In some embodiments, R X / Pmay be denoted as a ratio of N4 and N1 (N4 / N1), where N4 is a suitable value greater than 10, and N1 is as defined above. In some embodiments, 10 < N4 < 19, and N4 can also be any one of the following values: 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, 15, 15.5, 16, 16.5, 17, 17.5, 18, 18.5, 19, etc. For R X / P , N4 and N1 can be any combination. In some embodiments, R X / P may be selected from a suitable range of any two N4 / N1 values.

[0150] In some embodiments, 1 < R X / P ≤ 4.75 (equivalent to 10 / 10 < R X / P ≤ 19 / 4), and optionally, 1.3 < R X / P ≤ 4.7. Without limitation, R X / P may also be any one of the following values, greater than 1 and less than or equal to any one of the following values, or selected from a range of any two of the following values: 1.1, 1.2, 1.25, 1.3, 12 / 9, 1.4, 1.5, 1.6, 1.75, 1.8, 2, 2.2, 2.25, 2.4, 2.5, 2.6, 2.75, 2.8, 3, 3.2, 3.25, 3.5, 3.6, 3.75, 3.8, 4, 4.25, 4.5, 4.6, 4.75, etc.

[0151] In some embodiments, the M element is at least one of an Sb element and a Sn element.

[0152] In some embodiments, the M element includes an Sb element, and further can be an Sb element.

[0153] In some embodiments, the M element includes a Sn element, and further can be a Sn element.

[0154] In some embodiments, the M element is a combination of an Sb element and a Sn element.

[0155] In some embodiments, the X element is at least one of a Cl element and a Br element.

[0156] In some embodiments, the M element includes a Cl element, and further can be a Cl element.

[0157] In some embodiments, the M element includes a Br element, and further can be a Br element.

[0158] In some embodiments, the M element is a combination of a Cl element and a Br element.

[0159] In some embodiments, the argyrodite-type crystal phase satisfies one or more of the following characteristics (any numerical parameter in the following characteristics can also be selected from any suitable numerical value or range in the context):

[0160] The atomic number ratio of the M element and the P element in the argyrodite-type crystal phase is denoted as R M / P , the argyrodite-type crystal phase satisfies 0 < R M / P ≤ 1.5, and optionally, 0.1 ≤ R M / P ≤ 1.5;

[0161] The M element is at least one of an Sb element and a Sn element;

[0162] The atomic number ratio of the X element and the P element in the argyrodite-type crystal phase is denoted as R X / P , the argyrodite-type crystal phase satisfies 1 < R X / P ≤ 4.75, and optionally, 1.3 ≤ R X / P ≤ 4.7;

[0163] The X element is at least one of a Cl element and a Br element.

[0164] By controlling the atomic number ratio (R M / P ) of the M element and the P element in the above range, it is more conducive to maintaining good ionic conductivity while reducing the amount of hydrogen sulfide gas released by the sulfide solid electrolyte in a water-containing environment.

[0165] Both the Sb element and the Sn element can form stronger chemical bonds with soft acid and soft base (S), so that the chemical bonds are not easily destroyed by water molecules, the chemical stability of the material is significantly improved, and the amount of hydrogen sulfide gas released by the sulfide solid electrolyte in a water-containing environment can be significantly reduced.

[0166] In some embodiments, in the argyrodite-type crystal phase, the atomic number ratio of the Li element, the P element, the M element, the S element, and the X element is (6-x+z):(1-y-z):(y+z):(5-x):(1+x); wherein 0 < x ≤ 0.9, 0 ≤ y ≤ 0.2, 0 ≤ z ≤ 0.4, and (y+z) > 0;

[0167] At this time, R S / P = (5-x) / (1-y-z), R M / P = (y+z) / (1-y-z), and R X / P = (1+x) / (1-y-z).

[0168] In some embodiments, in the argyrodite-type crystal phase, the atomic amount ratio of Li element, P element, Sb element, Sn element, S element and Cl element is (6-x+z):(1-y-z):y:z:(5-x):(1+x); wherein, 0

[0169] In some embodiments, the chemical formula of the argyrodite-type crystal phase is Li 6-x+z P 1-y-z M y+z S 5-x X 1+x .

[0170] In some embodiments, the chemical formula of the argyrodite-type crystal phase is Li 6-x+z P 1-y-z Sb y Sn z S 5-x Cl 1+x .

[0171] By controlling the atomic amount ratio of Li element, P element, M element, S element and X element in the argyrodite-type crystal phase within the aforementioned range, it is more conducive to reducing the hydrogen sulfide gas release amount of the sulfide solid electrolyte in the aqueous environment while maintaining a better ionic conductivity.

[0172] Non-limitingly, 0

[0173] Non-limitingly, 0

[0174] Without limitation, 0 < z < 0.4, optionally, 0.05 < z < 0.4. Without limitation, z can also be any of the following values, or be selected from an interval consisting of any two of the following values: 0, 0.02, 0.04, 0.05, 0.06, 0.08, 0.1, 0.12, 0.14, 0.15, 0.16, 0.18, 0.2, 0.22, 0.24, 0.25, 0.26, 0.28, 0.3, 0.32, 0.34, 0.35, 0.36, 0.38, 0.4, etc.

[0175] In the present application, (y + z) > 0, unless otherwise specified.

[0176] Without limitation, 0 < (y + z) < 0.6, optionally, 0.1 < (y + z) < 0.6. Without limitation, y + z can also be any of the following values, greater than 0 and less than or equal to any of the following values, or be selected from an interval consisting of any two of the following values: 0.02, 0.04, 0.05, 0.06, 0.08, 0.1, 0.12, 0.14, 0.15, 0.16, 0.18, 0.2, 0.22, 0.24, 0.25, 0.26, 0.28, 0.3, 0.32, 0.34, 0.35, 0.36, 0.38, 0.4, 0.42, 0.44, 0.45, 0.46, 0.48, 0.5, 0.52, 0.54, 0.55, 0.56, 0.58, 0.6, etc.

[0177] In some embodiments, the argyrodite-type crystalline phase satisfies one or more of the following characteristics (any of the numerical parameters in the following characteristics can also be selected from any suitable value or range in the context):

[0178] x satisfies 0 < x < 0.9, optionally, 0.2 < x < 0.9;

[0179] y satisfies 0 < y < 0.2, optionally, 0.05 < y < 0.2;

[0180] z satisfies 0 < z < 0.4, optionally, 0.05 < z < 0.4;

[0181] y and z satisfy 0 < (y + z) < 0.6, optionally, 0.1 < (y + z) < 0.6.

[0182] By controlling one or more of the parameters x, y, z within the aforementioned ranges, it is more advantageous to reduce the amount of hydrogen sulfide gas released by the sulfide solid electrolyte in an aqueous environment while also maintaining a good ionic conductivity.

[0183] By controlling y in the aforementioned range, the P element content can be reduced while achieving sufficient solid solution of the Sb element in the crystal structure, which is conducive to reducing impurities and achieving better ionic conductivity.

[0184] By controlling z in the aforementioned range, the P element content can be reduced while achieving sufficient solid solution of the Sn element in the crystal structure, which is conducive to reducing impurities and achieving better ionic conductivity.

[0185] In the present application, in the argyrodite-type crystal phase, the atomic ratio of Li element to P element can be denoted as R Li / P .

[0186] In some embodiments, R Li / P may be denoted as the ratio of N5 and N1 (N5 / N1), where N5 can be a suitable value greater than or equal to 51, and N1 can refer to the definition above. In some embodiments, 51≤N5<64, and N5 can also be any of the following values: 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 63.5, etc. N5 and N1 can be any combination for R Li / P . Li / P In some embodiments, R Li / P may be selected from a suitable interval of any two N5 / N1 values.

[0187] In some embodiments, 5.1<R Li / P <16, and optionally, 6.5≤R Li / P ≤13.7. Without limitation, R Li / P may also be any of the following values, greater than 5.1 and less than or equal to any of the following values, greater than or equal to any of the following values and less than 16, greater than or equal to any of the following values and less than 12.5, or selected from an interval of any two of the following values: 5.2, 5.5, 55 / 9.5, 55 / 9, 6, 52 / 8.5, 57.5 / 9, 6.5 (equal to 52 / 8), 55 / 8 (equal to 6.875), 7, 7.5, 53 / 7, 8 (equal to 56 / 7), 8.5, 9, 9.5 (equal to 57 / 6), 10, 10.2, 10.25, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 13.7, 13.75 (equal to 55 / 4), 14, 14.5, 15, 15.5, etc.

[0188] In the present application, in the argyrodite-type crystal phase, the atomic ratio of Cl element to P element can be denoted as R Cl / P .

[0189] In some embodiments, R Cl / Pmay be denoted by the ratio of N4 and N1 (N4 / N1), where N4 can be defined as above and N1 can be defined as above. For R Cl / P , N4 and N1 can be in any combination. In some embodiments, R Cl / P may be selected from a suitable interval of any two N4 / N1 values.

[0190] In some embodiments, 1 < R Cl / P ≤ 4.75 (equivalent to 10 / 10 < R Cl / P ≤ 19 / 4), and further optionally, 1.3 < R Cl / P ≤ 4.7. R Cl / P may also be any of the following values, greater than 1 and less than or equal to any of the following values, or selected from an interval of any two of the following values: 1.1, 1.2, 1.25, 1.3, 12 / 9, 1.4, 1.5, 1.6, 1.75, 1.8, 2, 2.2, 2.25, 2.4, 2.5, 2.6, 2.75, 2.8, 3, 3.2, 3.25, 3.5, 3.6, 3.75, 3.8, 4, 4.25, 4.5, 4.6, 4.75, etc. As non-limiting examples, R Cl / P may also be selected from any of the following ranges: 12 / 9 < R Cl / P ≤ 4.75, 1.3 < R Cl / P ≤ 4.75, 12 / 9 < R Cl / P ≤ 4.7, etc.

[0191] In this application, in the argyrodite-type crystal phase, the atomic number ratio of Sb element and P element can be denoted by R Sb / P , the atomic number ratio of Sn element and P element can be denoted by R Sn / P , and the atomic number ratio of the sum of Sb element and Sn element relative to P element can be denoted by R (Sb+Sn) / P . Numerically, R (Sb+Sn) / P = R Sb / P + R Sn / P .

[0192] In some embodiments, numerically, R (Sb+Sn) / P may be denoted by the ratio of N3 and N1 (N3 / N1), where N3 can be defined as above and N1 can be defined as above. For R (Sb+Sn) / P , N3 and N1 can be in any combination. In some embodiments, R (Sb+Sn) / P may be selected from a suitable interval of any two N3 / N1 values. In some of these embodiments, N3+N1=10.

[0193] In some embodiments, 0 < R (Sb+Sn) / P ≤ 1.5, and optionally, 0.1 < R (Sb+Sn) / P ≤ 1.5. R(Sb+Sn) / P Also, each of the following values, greater than 0 and less than or equal to each of the following values, or selected from the interval consisting of any two of the following values, can be satisfied: 0.05, 0.053, 5 / 9.5, 0.1, 1 / 9, 0.125, 0.15, 0.2, 0.25 (equal to 2 / 8), 0.3, 0.35, 0.4, 0.425, 3 / 7, 0.45, 0.5, 0.6, 0.625, 0.64, 0.65, 4 / 6, 0.7, 0.75, 0.8, 0.825, 0.9, 0.95, 1, 1.05, 1.1, 1.2, 1.25, 1.3, 1.4, 1.45, 1.5 (equal to 6 / 4), and the like.

[0194] In some embodiments, 0 < (R Sb / P + R Sn / P ) ≤ 1.5, optionally, 0.1 ≤ (R Sb / P + R Sn / P ) ≤ 1.5.

[0195] In some embodiments, the argyrodite-type crystal phase satisfies one or more of the following characteristics (any numerical parameter in the following characteristics can also be selected from any suitable numerical value or range in the context):

[0196] In the argyrodite-type crystal phase, the atomic number ratio of Li element and P element is denoted as R Li / P , which satisfies 5.1 < R Li / P < 16, optionally, 6.5 ≤ R Li / P ≤ 13.7;

[0197] In the argyrodite-type crystal phase, the atomic number ratio of Cl element and P element is denoted as R Cl / P , which satisfies 1 < R Cl / P ≤ 4.75, optionally, 1.3 ≤ R Cl / P ≤ 4.7;

[0198] In the argyrodite-type crystal phase, the atomic number ratio of Sb element and P element is denoted as R Sb / P , the atomic number ratio of Sn element and P element is denoted as R Sn / P , which satisfies 0 < (R Sb / P + R Sn / P ) ≤ 1.5, optionally, 0.1 ≤ (R Sb / P + R Sn / P ) ≤ 1.5.

[0199] By the atomic number ratio of Li element and P element (R Li / P ), the atomic number ratio of Cl element and P element (R Cl / P ), the sum of the atomic number ratio of Sb element and Sn element and the atomic number ratio of P element (R Sb / P + RSn / P controlling the one or more parameters in the foregoing ranges is conducive to reducing the release of hydrogen sulfide gas from the sulfide solid electrolyte in an aqueous environment while maintaining a good ionic conductivity.

[0200] In some embodiments, R Sb / P ≤ R Sn / P , and R Sb / Sn ≤ 1.

[0201] In some embodiments, R Sb / P < R Sn / P , and R Sb / Sn < 1.

[0202] In some embodiments, in the argyrodite crystal phase, the atomic ratio of the Sb element to the Sn element is denoted as R Sb / Sn Non-limitingly, R Sb / Sn may be (0-1):(0-1), optionally (0-1):1, and further optionally 1:(0-1).

[0203] In some embodiments, 0≤ R Sb / Sn ≤ 1, and optionally 0.5≤ R Sb / Sn ≤ 1. Non-limitingly, R Sb / Sn may also be any of the following values, or a range selected from any two of the following values: 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.55, 0.6, 0.625, 0.64, 0.65, 0.7, 0.75, 0.8, 0.825, 0.9, 0.95, 1, etc.

[0204] By controlling the atomic ratio of the Sb element to the Sn element (R Sb / Sn ) in the foregoing ranges, it is more conducive to achieving sufficient solid solution of the Sb element and the Sn element while reducing the content of the P element, and more conducive to reducing the release of hydrogen sulfide gas from the sulfide solid electrolyte in an aqueous environment while maintaining a good ionic conductivity.

[0205] In some embodiments, in the argyrodite crystal phase, the atomic ratio of the Sn element to the Sb element is denoted as R Sn / Sb , and satisfies 0≤ R Sn / Sb ≤ 1, and optionally 0.5≤ R Sn / Sb ≤ 1. Non-limitingly, R Sn / Sb may also be any of the following values, or a range selected from any two of the following values: 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.55, 0.6, 0.625, 0.64, 0.65, 0.7, 0.75, 0.8, 0.825, 0.9, 0.95, 1, etc.

[0206] In some embodiments, the argyrodite-type crystal phase has any one of the following chemical formulae: Li 5.5 P 0.9 Sb 0.1 S 4.5 Cl 1.5 , Li 5.6 P 0.7 Sn 0.3 S 4.3 Cl 1.7 , and Li 5.2 P 1.8 Sb 0.1 Sn 0.1 S 4.1 Cl 1.9 .

[0207] By disposing one or more of the aforementioned argyrodite-type crystal phases in the sulfide solid electrolyte, it is more advantageous to balance the reduction of hydrogen sulfide gas release and better ionic conductivity.

[0208] In some embodiments, the 2theta (°) diffraction angles in the X-ray diffraction pattern of the sulfide solid electrolyte have characteristic peaks consistent with the argyrodite-type crystal phase. For the definition and identification method of the “argyrodite-type crystal phase”, please refer to the foregoing.

[0209] In some embodiments, the 2theta (°) diffraction angles in the X-ray diffraction pattern of the sulfide solid electrolyte have peaks at 15.5±δ°, 18.1±δ°, 25.6±δ°, 30.1±δ°, 31.4±δ°, 39.8±δ°, 45.1±δ°, 47.9±δ°, and 52.5±δ°, wherein δ can be referred to the foregoing; optionally, δ is 0.2 or 0.1.

[0210] In some embodiments, the 2theta (°) diffraction angles in the X-ray diffraction pattern of the sulfide solid electrolyte have peaks at 15.5±0.2°, 18.1±0.2°, 25.6±0.2°, 30.1±0.2°, 31.4±0.2°, 39.8±0.2°, 45.1±0.2°, 47.9±0.2°, and 52.5±0.2°.

[0211] In some embodiments, the X-ray diffraction pattern of the sulfide solid electrolyte is obtained by using Cu Kα rays, and in some of the embodiments, the X-ray diffraction pattern of the sulfide solid electrolyte is obtained by using Cu Kα1 rays.

[0212] In some embodiments, the X-ray diffraction pattern of the sulfide solid electrolyte is obtained by powder X-ray diffraction testing.

[0213] In some embodiments, the sulfide solid electrolyte satisfies at least one of the following characteristics:

[0214] The sulfide solid electrolyte has peaks at 2-theta (°) diffraction angles of 15.5±δ°, 18.1±δ°, 25.6±δ°, 30.1±δ°, 31.4±δ°, 39.8±δ°, 45.1±δ°, 47.9±δ°, and 52.5±δ° in the X-ray diffraction pattern thereof, wherein δ can refer to the foregoing; optionally, δ is 0.2 or 0.1 (in some embodiments, δ is 0.2; in other embodiments, δ is 0.1);

[0215] The X-ray diffraction pattern of the sulfide solid electrolyte is obtained by using Cu Kα rays;

[0216] The X-ray diffraction pattern of the sulfide solid electrolyte is obtained by powder X-ray diffraction testing.

[0217] The chemical composition in the sulfide solid electrolyte can be confirmed by X-ray diffraction (XRD) detection.

[0218] In a second aspect of the present application, a preparation method of a sulfide solid electrolyte is provided, which can be used to prepare the sulfide solid electrolyte described in the first aspect of the present application.

[0219] In some embodiments, the preparation method of the sulfide solid electrolyte comprises the following steps:

[0220] S100: providing a precursor mixture comprising Li2S, P2S5, LiX, a M source, and elemental sulfur according to the stoichiometric ratio of the required raw materials; wherein X is a halogen; the M source is a raw material providing M elements;

[0221] Optionally, X comprises one or more elements of Cl and Br;

[0222] Optionally, the M elements comprise at least one of Sb elements and Sn elements; further optionally, when the sulfide solid electrolyte contains Sb elements, the precursor mixture further comprises Sb2S3; when the sulfide solid electrolyte contains Sn elements, the precursor mixture comprises SnS2;

[0223] S200: sintering the precursor mixture in an inert atmosphere to prepare a sulfide solid electrolyte comprising argyrodite-type crystal phase;

[0224] The atomic number ratio of X elements to P elements in the argyrodite-type crystal phase is denoted as R X / P The atomic number ratio of S elements to P elements in the argyrodite-type crystal phase is denoted as R S / P In some embodiments, the argyrodite-type crystal phase satisfies R X / P >1 and RS / P >4.1.

[0225] In the present application, unless otherwise specified, the "providing in stoichiometric ratio required by the raw materials" involved in step S100 refers to providing in stoichiometric ratio required by the raw materials to obtain the target chemical formula. In the case where the target chemical formula is determined, the skilled person in the art can select appropriate precursor raw materials and appropriate stoichiometric ratio of raw materials. During the sintering process of step S200, evaporation loss of sulfur usually occurs. Therefore, in step S100, elemental sulfur is usually added in excess.

[0226] Non-limitingly, the weight percentage of elemental sulfur relative to the precursor mixture can be 3.9wt%~4.1wt%, for example 3.9wt%, 4wt%, 4.1wt%, etc.

[0227] Non-limitingly, in step S200, the sintering temperature can be 450℃~530℃, and can also be any two temperatures selected from the following or a range formed by any two temperatures selected from the following: 450℃, 460℃, 470℃, 480℃, 490℃, 500℃, 510℃, 520℃, 530℃, etc.

[0228] Non-limitingly, in step S200, the inert atmosphere can be an argon atmosphere.

[0229] In some embodiments, the method for preparing the sulfide solid electrolyte satisfies one or more of the following characteristics (any numerical parameter in the following characteristics can also be selected from any suitable numerical value or range in the context):

[0230] The weight ratio of elemental sulfur relative to the precursor mixture is 3.9wt%~4.1wt%;

[0231] The inert atmosphere is an argon atmosphere;

[0232] The temperature for sintering is 450℃~530℃;

[0233] The prepared sulfide solid electrolyte is the sulfide solid electrolyte described in the first aspect of the present application.

[0234] The sulfide solid electrolyte described in the first aspect of the present application can be obtained by sintering the corresponding precursor mixture in the presence of excess elemental sulfur at a certain sintering temperature.

[0235] In the third aspect of the present application, a solid electrolyte film is provided, which comprises at least one of the sulfide solid electrolyte described in the first aspect of the present application and the sulfide solid electrolyte prepared by the method described in the second aspect of the present application.

[0236] Without limitation, the solid electrolyte film can be a stand-alone solid electrolyte film piece, which in turn is used to assemble a solid-state battery; the solid electrolyte film can also be a solid electrolyte film layer present in a composite structure.

[0237] The solid electrolyte film can be prepared using conventional methods in the field of solid-state batteries, such as pressing the solid electrolyte material into a film.

[0238] In some embodiments, the solid electrolyte film is a full solid-state electrolyte film.

[0239] In the present application, unless otherwise specified, a “full solid-state electrolyte film” refers to a solid electrolyte film whose constituent materials are all in solid state.

[0240] In another aspect of the present application, a solid electrolyte film piece is provided, which includes at least one of the sulfide solid electrolyte described in the first aspect of the present application and the sulfide solid electrolyte prepared by the preparation method described in the second aspect of the present application.

[0241] In another aspect of the present application, a positive electrode film is provided, which includes a positive electrode active material layer, the positive electrode active material layer including at least one of the sulfide solid electrolyte described in the first aspect of the present application and the sulfide solid electrolyte prepared by the preparation method described in the second aspect of the present application.

[0242] Without limitation, the positive electrode film can be a stand-alone positive electrode film piece or a positive electrode tab, which in turn is used to assemble a solid-state battery; the positive electrode film can also be a positive electrode film layer present in a multi-layer composite structure, for example, the constituent materials of the positive electrode film layer can be pressed into a film on the surface of a solid electrolyte layer. As a non-limiting example, the positive electrode film can be a positive electrode layer or a portion of a positive electrode layer of a solid-state battery.

[0243] In some embodiments, the negative electrode film is a full solid-state positive electrode film.

[0244] In the present application, unless otherwise specified, a “full solid-state positive electrode film” refers to a positive electrode film whose constituent materials are all in solid state.

[0245] In another aspect of the present application, a positive electrode film piece is provided, which includes a positive electrode current collector and a positive electrode active material layer located on at least one side of the positive electrode current collector, the positive electrode active material layer including at least one of the sulfide solid electrolyte described in the first aspect of the present application and the sulfide solid electrolyte prepared by the preparation method described in the second aspect of the present application.

[0246] In another aspect of the present application, a negative electrode film is provided, which includes a negative electrode active material layer, the negative electrode active material layer including at least one of the sulfide solid electrolyte described in the first aspect of the present application and the sulfide solid electrolyte prepared by the preparation method described in the second aspect of the present application.

[0247] Without limitation, the negative electrode film can be a stand-alone negative electrode film or negative electrode tab, which is further used for assembling a solid-state battery; the negative electrode film can also be a negative electrode film layer present in a multi-layer composite structure, for example, the constituent materials of the negative electrode film layer can be pressed into a film on the surface of a solid electrolyte layer. As a non-limiting example, the negative electrode film can be a negative electrode layer or a part of a negative electrode layer of a solid-state battery.

[0248] In some embodiments, the negative electrode film is a full solid-state negative electrode film.

[0249] In the present application, unless otherwise specified, the "full solid-state negative electrode film" refers to a negative electrode film with all constituent materials in a solid state.

[0250] In another aspect of the present application, a negative electrode tab is provided, which comprises a negative electrode current collector and a negative electrode active material layer located on at least one side of the negative electrode current collector, the negative electrode active material layer comprising at least one of the sulfide solid electrolyte described in the first aspect of the present application and the sulfide solid electrolyte prepared by the preparation method described in the second aspect of the present application.

[0251] For the solid electrolyte film, the positive electrode film or the negative electrode film provided with the aforementioned sulfide solid electrolyte, the sulfide solid electrolyte has high stability in a water-containing environment (such as air) and low hydrogen sulfide release amount, and the material has good chemical stability, so that the sulfide solid electrolyte in the solid electrolyte film, the positive electrode film or the negative electrode film has good quality stability, which is beneficial to make the corresponding secondary battery or solid-state battery fully exert the high ionic conductivity advantage of the sulfide solid electrolyte, and the cycle performance can be good.

[0252] In the fourth aspect of the present application, an electrode tab is provided, which comprises an electrode active material layer, the electrode active material layer comprising an electrode active substance, and the electrode active material layer further comprising at least one of the sulfide solid electrolyte described in the first aspect of the present application and the sulfide solid electrolyte prepared by the preparation method described in the second aspect of the present application.

[0253] In some embodiments, the electrode tab is a positive electrode tab, the electrode active material layer is referred to as a positive electrode active material layer, and the electrode active substance is referred to as a positive electrode active substance.

[0254] Alternatively, the electrode tab is a negative electrode tab, the electrode active material layer is referred to as a negative electrode active material layer, and the electrode active substance is referred to as a negative electrode active substance.

[0255] In the present application, the electrode tab includes an electrode active material layer unless otherwise specified. As previously described, the electrode active material layer includes an electrode active substance. In the electrode tab, the electrode active substance can itself constitute a particulate substance or can be contained in an electrode active particle. Unless otherwise specified, the electrode active material layer in the electrode tab provided in this aspect further includes a sulfide solid electrolyte, and further, the electrode active material layer includes at least one of the sulfide solid electrolyte described in the first aspect of the present application and the sulfide solid electrolyte prepared by the preparation method described in the second aspect of the present application.

[0256] In some embodiments, the electrode active material layer includes an electrode active particle, and the electrode active material layer further includes at least one of the sulfide solid electrolyte described in the first aspect of the present application and the sulfide solid electrolyte prepared by the preparation method described in the second aspect of the present application. The electrode tab can be a positive electrode tab, and the electrode active particle is a positive electrode active particle. In this case, a positive electrode tab is provided, which includes a positive electrode active material layer including the positive electrode active particle and the aforementioned sulfide solid electrolyte. The electrode tab can also be a negative electrode tab, and the electrode active particle is a negative electrode active particle. In this case, a negative electrode tab is provided, which includes a negative electrode active material layer including the negative electrode active particle and the aforementioned sulfide solid electrolyte.

[0257] For the electrode tab provided with the aforementioned sulfide solid electrolyte, the sulfide solid electrolyte has high stability in a water-containing environment (such as air) and low hydrogen sulfide release amount, and the material has good chemical stability, so that the electrode tab has good quality stability. A secondary battery or a solid-state battery assembled using the electrode tab can fully utilize the high ionic conductivity advantage of the sulfide solid electrolyte and can have good cycle performance.

[0258] The electrode tab can be a positive electrode tab or a negative electrode tab.

[0259] In still another aspect of the present application, a secondary battery is provided, which includes at least one of the sulfide solid electrolyte described in the first aspect of the present application, the sulfide solid electrolyte prepared by the preparation method described in the second aspect of the present application, the solid electrolyte film described in the third aspect of the present application, the aforementioned positive electrode film, the aforementioned negative electrode film, and the electrode tab described in the fourth aspect of the present application.

[0260] In the present application, the "secondary battery" provided in the foregoing aspects of the present application includes a positive electrode tab, a negative electrode tab, and a solid electrolyte layer between the positive electrode tab and the negative electrode tab unless otherwise specified.

[0261] In the present application, the "positive electrode tab" includes a positive electrode active material layer unless otherwise specified. In some embodiments, the positive electrode tab in the secondary battery is the aforementioned positive electrode film.

[0262] In the present application, unless otherwise specified, the "negative electrode sheet" includes the negative active material layer. In some embodiments, the negative electrode sheet in the secondary battery is the aforementioned negative electrode film.

[0263] In the present application, unless otherwise specified, the "solid electrolyte layer" includes the solid electrolyte. In some embodiments, the solid electrolyte layer is a solid electrolyte film layer composed of the solid electrolyte film described in the third aspect of the present application.

[0264] During charging of the secondary battery, active ions are extracted from the positive electrode and inserted into the negative electrode through the solid electrolyte layer; while during discharging of the secondary battery, active ions are extracted from the negative electrode and inserted into the positive electrode. The active ions are not particularly limited, and non-limitingly, the active ions can be lithium ions, in which case it is a lithium ion secondary battery.

[0265] In the fifth aspect of the present application, there is provided a solid-state battery comprising at least one of the sulfide solid electrolyte described in the first aspect of the present application, the sulfide solid electrolyte prepared by the preparation method described in the second aspect of the present application, the solid electrolyte film described in the third aspect of the present application, the aforementioned positive electrode film, the aforementioned negative electrode film, and the electrode sheet described in the fourth aspect of the present application.

[0266] In some embodiments, the solid-state battery comprises at least one of the sulfide solid electrolyte described in the first aspect of the present application, the sulfide solid electrolyte prepared by the preparation method described in the second aspect of the present application, the solid electrolyte film described in the third aspect of the present application, and the electrode sheet described in the fourth aspect of the present application.

[0267] In some embodiments, the positive electrode layer in the solid-state battery comprises the aforementioned positive electrode film, and further can be the aforementioned positive electrode film.

[0268] In some embodiments, the negative electrode layer in the solid-state battery comprises the aforementioned negative electrode film, and further can be the aforementioned negative electrode film.

[0269] In some embodiments, the solid electrolyte layer in the solid-state battery comprises the solid electrolyte film described in the third aspect of the present application, and further can be the solid electrolyte film described in the third aspect of the present application.

[0270] In some embodiments, the solid-state battery is a sulfide all-solid-state battery.

[0271] The "solid-state battery" provided in the fifth aspect of the present application comprises at least one of the sulfide solid electrolyte described in the first aspect of the present application and the sulfide solid electrolyte prepared by the preparation method described in the second aspect of the present application, and thus it is a sulfide all-solid-state battery.

[0272] In the present application, unless otherwise specified, "sulfide solid-state battery" refers to a solid-state battery in which the electrolyte involved in the battery includes a sulfide solid electrolyte. The sulfide solid electrolyte can be located in at least one of the positive electrode layer, the negative electrode layer, and the solid electrolyte layer of the sulfide solid-state battery. The sulfide solid-state battery can further be a full solid-state battery.

[0273] In the present application, unless otherwise specified, "full solid-state battery" refers to a solid-state battery in which the electrolyte in the battery is a solid electrolyte. At this time, the positive electrode layer, the negative electrode layer, and the electrolyte part all use solid materials, and no liquid electrolyte is provided in the battery, so it can be called a "full solid-state battery".

[0274] In the present application, unless otherwise specified, "solid-state battery" in any embodiment or example can be, but is not limited to, a sulfide full solid-state battery. Unless otherwise specified, "sulfide full solid-state battery" refers to a full solid-state battery in which the electrolyte involved in the battery includes a sulfide solid electrolyte. Among them, the sulfide solid electrolyte can be located in at least one of the positive electrode layer, the negative electrode layer, and the solid electrolyte layer of the sulfide full solid-state battery.

[0275] The types of solid electrolytes present in different film layers of the secondary battery or the solid-state battery can be the same or different. For example, the positive electrode electrolyte particles, the negative electrode electrolyte particles, and the solid electrolyte in the solid electrolyte layer can be the same or different.

[0276] In the secondary battery or the solid-state battery provided in the present application, at least one of the positive electrode electrolyte particles, the negative electrode electrolyte particles, and the solid electrolyte in the solid electrolyte layer comprises the sulfide solid electrolyte described in the first aspect of the present application.

[0277] For the secondary battery or the solid-state battery provided with the aforementioned sulfide solid electrolyte, the sulfide solid electrolyte can be provided in one or more of the positive electrode layer, the negative electrode layer, and the solid electrolyte layer.

[0278] As non-limiting examples, the positive electrode electrolyte particles, the negative electrode electrolyte particles, and the solid electrolyte in the solid electrolyte layer can each independently include a solid electrolyte material known in the art that can be used in a solid-state battery, for example, can each independently include one or more of the following materials: one or more of a sulfide-based solid electrolyte, a halide-based solid electrolyte, an oxide-based solid electrolyte, a polymer-based solid electrolyte, and the like.

[0279] In a sixth aspect of the present application, a power device is provided, which comprises at least one of the sulfide solid electrolyte of the first aspect of the present application, the sulfide solid electrolyte prepared by the preparation method of the second aspect of the present application, the solid electrolyte film of the third aspect of the present application, the positive electrode film, the negative electrode film, the electrode tab of the fourth aspect of the present application, the secondary battery and the solid-state battery of the fifth aspect of the present application.

[0280] In some embodiments, the power device comprises at least one of the sulfide solid electrolyte of the first aspect of the present application, the sulfide solid electrolyte prepared by the preparation method of the second aspect of the present application, the solid electrolyte film of the third aspect of the present application, the electrode tab of the fourth aspect of the present application and the solid-state battery of the fifth aspect of the present application.

[0281] Some descriptions about the solid electrolyte layer are as follows.

[0282] The solid electrolyte layer plays a role of conducting ions between the positive electrode layer and the negative electrode layer, and also plays a role of isolating the positive electrode layer from the negative electrode layer to prevent short circuit between the positive electrode and the negative electrode.

[0283] It can be understood that the solid electrolyte layer comprises a solid electrolyte. The solid electrolyte in the solid electrolyte layer can adopt a solid electrolyte material known in the art and applicable to a solid-state battery.

[0284] In some embodiments, the solid electrolyte layer comprises the sulfide solid electrolyte of the first aspect of the present application.

[0285] In some embodiments, the solid electrolyte layer can be pressed from a solid electrolyte material into a solid electrolyte film, which can be a solid electrolyte film sheet or a solid electrolyte film layer.

[0286] In some embodiments, the thickness of the solid electrolyte layer can be 0.1 μm to 1000 μm, optionally 10 μm to 100 μm, 100 μm to 800 μm, 500 μm to 800 μm, etc.

[0287] Some descriptions about the positive electrode film and the positive electrode layer are as follows.

[0288] In the present application, unless otherwise specified, the "positive electrode film" refers to a film capable of being used as a positive electrode of a solid-state battery, which at least comprises a positive electrode active material layer, and usually further comprises a positive electrode current collector.

[0289] The positive electrode layer can be provided by a positive electrode tab or a positive electrode film sheet applicable to a solid-state battery in the art, or the constituent materials of the positive electrode layer can be directly pressed into a positive electrode film layer on one side surface of the solid electrolyte layer. The positive electrode film sheet can be compounded with other films suitable for a positive electrode to form a positive electrode tab or a positive electrode layer.

[0290] The positive electrode layer can be prepared by a dry method or a wet method. For example, a dry method can be used to press a positive electrode film, which can be a positive electrode sheet or a positive electrode layer. For another example, a wet method can be used to coat a positive electrode film, which can be a positive electrode layer.

[0291] In some embodiments, the positive electrode film comprises a positive electrode current collector and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector, and the positive electrode active material layer is as defined above.

[0292] In some embodiments, the positive electrode current collector can be a metal foil or a composite current collector. For example, as the metal foil, an aluminum foil can be used. In the positive electrode current collector, the composite current collector can comprise a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer. In the positive electrode current collector, the composite current collector can be obtained by forming a metal material on a polymer material base material. In the positive electrode current collector, non-limiting examples of the metal material can include one or more of aluminum, an aluminum alloy, nickel, a nickel alloy, titanium, a titanium alloy, silver, a silver alloy, and the like. In the positive electrode current collector, non-limiting examples of the polymer material base material can include one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), and the like.

[0293] Non-limitingly, in the positive electrode film or the positive electrode layer, the thickness of the positive electrode active material layer is 30 μm to 400 μm, which can be optionally 60 μm to 130 μm, and can also be any one of the following thicknesses or a range of thicknesses selected from any two of the following thicknesses: 30 μm, 40 μm, 50 μm, 60 μm, 80 μm, 100 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 180 μm, 200 μm, and the like.

[0294] In the present application, unless otherwise specified, the "thickness of the positive electrode active material layer" refers to the total thickness in the positive electrode film or the positive electrode layer. When the positive electrode active material layer is disposed on both sides of the positive electrode current collector, the thickness of the positive electrode active material layer refers to the sum of the thicknesses of the two sides.

[0295] As a non-limiting example, the positive electrode current collector has two surfaces facing away from each other in the thickness direction thereof, and the positive electrode active material layer is disposed on any one or both of the two surfaces of the positive electrode current collector facing away from each other.

[0296] The positive electrode film and the positive electrode layer each comprise a positive electrode active material layer, and the positive electrode active material layer comprises positive electrode active particles containing a positive electrode active material.

[0297] Non-limitingly, the weight percentage of the positive electrode active particles or positive electrode active material in the positive electrode active material layer can be ≥ 70 wt%, further can be ≥ 80 wt%, more further can be ≥ 90 wt%, and can also be any one of the following weight percentages or a range consisting of any two of the following weight percentages: 70 wt%, 75 wt%, 80 wt%, 82 wt%, 84 wt%, 85 wt%, 86 wt%, 88 wt%, 90 wt%, 92 wt%, 94 wt%, 95 wt%, 96 wt%, 97 wt%, 98 wt%, 99 wt%, etc.

[0298] In some embodiments, the positive electrode active material layer comprises positive electrode electrolyte particles. Non-limitingly, the weight percentage of the positive electrode electrolyte particles in the positive electrode active material layer can be 0.1 wt% to 30 wt%, and can be optionally 5 wt% to 20 wt%, and the weight percentage of the positive electrode electrolyte particles in the positive electrode active material layer can also be any one of the following weight percentages or a range consisting of any two of the following weight percentages: 0.1 wt%, 0.2 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.8 wt%, 1 wt%, 1.2 wt%, 1.5 wt%, 1.6 wt%, 1.8 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 12 wt%, 14 wt%, 15 wt%, 16 wt%, 18 wt%, 20 wt%, 22 wt%, 24 wt%, 25 wt%, 26 wt%, 28 wt%, 30 wt%, etc.

[0299] In some embodiments, the positive electrode active material layer comprises positive electrode active particles and positive electrode electrolyte particles.

[0300] In some embodiments, the positive electrode active material in the positive electrode active particles can employ a positive electrode active material for a battery known in the art. As non-limiting examples, the positive electrode active material can include one or more of a lithium-containing phosphate of olivine structure, a lithium transition metal oxide, and respective modified compounds thereof. However, the present application is not limited to these materials, and other conventional materials that can be used as a positive electrode active material for a battery can also be used. These positive electrode active materials can be used alone only one kind, or two or more kinds in combination. Among them, examples of the lithium transition metal oxide can include, but are not limited to, one or more of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, and modified compounds thereof. Non-limiting examples of the lithium-containing phosphate of olivine structure can include, but are not limited to, one or more of lithium iron phosphate, a composite of lithium iron phosphate and carbon, lithium manganese phosphate, a composite of lithium manganese phosphate and carbon, lithium manganese iron phosphate, a composite of lithium manganese iron phosphate and carbon. Non-limiting examples of the lithium cobalt oxide can include LiCoO2; non-limiting examples of the lithium nickel oxide can include LiNiO2; non-limiting examples of the lithium manganese oxide can include LiMnO2, LiMn2O4, and the like; non-limiting examples of the lithium nickel cobalt manganese oxide can include LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2(also can be referred to simply as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O2(also can be referred to simply as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2(also can be referred to simply as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2(also can be referred to simply as NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O2(also can be referred to simply as NCM 811 ), and the like. Non-limiting examples of the lithium nickel cobalt aluminum oxide can include LiNi 0.80 Co 0.15 Al 0.05 O2. An example of the lithium iron phosphate is LiFePO4(also can be referred to simply as LFP). An example of the lithium manganese phosphate is LiMnPO4.

[0301] In the case of solid-state batteries with active ions including lithium ions, it is understandable that the solid-state batteries will be accompanied by lithium (Li) deintercalation and consumption during charging and discharging, and the content of Li in the positive electrode layer is different when the battery is discharged to different states. In the exemplary description of the positive electrode active material in this application, unless otherwise stated, the content of Li can be the initial state of the material or the non-initial state after charging and discharging cycle. When the positive electrode active material is applied to the positive electrode layer in the solid-state battery system, the content of Li in the positive electrode active material contained in the positive electrode layer will usually change after charging and discharging cycle. The content of Li can be measured by atomic molar content, but is not limited thereto. As for "the content of Li in the initial state of the material", the initial state of the material refers to the state before being placed in the positive electrode layer. It can be understood that new materials or new substances obtained by proper modification of the listed positive electrode active materials are also within the scope of positive electrode active materials, and the foregoing proper modification refers to acceptable modification methods for positive electrode active materials, and non-limiting examples include coating modification. In the exemplary description of the positive electrode active material in this application, the content of oxygen (O) is usually the theoretical state value, and the release of oxygen from the lattice will cause the atomic molar content of oxygen to change, and the actual content of O will fluctuate. The content of O can be measured by atomic molar content, but is not limited thereto.

[0302] In some embodiments, the positive electrode active material layer includes a conductive agent (which can be referred to as a positive electrode conductive agent). As a non-limiting example, the positive electrode conductive agent can be a carbon conductive agent. Non-limitingly, the carbon conductive agent can include one or more of super P, acetylene black, carbon black, ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers. In some embodiments, the positive electrode conductive agent can include, but is not limited to, one or more of SP, KS-6, acetylene black, branched ketjen black ECP, SFG-6, vapor grown carbon fiber VGCF, carbon nanotubes (CNTs), and graphene. Non-limitingly, the weight percentage of the positive electrode conductive agent in the positive electrode active material layer can be 0-10 wt%, further can be 0-8 wt%, further can be 0-5 wt%, further can be 0.1 wt%-3 wt%, based on the total weight of the positive electrode active material layer. The weight percentage of the positive electrode conductive agent in the positive electrode active material layer can also be 0.1 wt%-5 wt%, 0.2 wt%-5 wt%, 0.5 wt%-5 wt%, 0.1 wt%-3 wt%, etc.

[0303] In some embodiments, the positive electrode active material layer optionally comprises a binder (may be referred to as a positive electrode binder). As non-limiting examples, the positive electrode binder can comprise one or more of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), a vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, a vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, a tetrafluoroethylene-hexafluoropropylene copolymer, and a fluorine-containing acrylate resin. Typically, the weight percentage of the positive electrode binder in the positive electrode active material layer can be 0-10 wt%, further can be 0-8 wt%, further can be 0.1 wt%-5 wt%, further can be 1 wt%-5 wt%, based on the total weight of the positive electrode active material layer.

[0304] Non-limitingly, the positive electrode active material layer can comprise positive electrode active particles, positive electrode electrolyte particles, a positive electrode conductive agent, and a positive electrode binder. The types and contents of the components can be referred to the context of the present application.

[0305] In some embodiments, the positive electrode electrolyte particles comprise the sulfide solid electrolyte described in the first aspect of the present application.

[0306] In some embodiments, the positive electrode film (may be referred to as a positive electrode sheet) can be prepared by dry mixing the components described above for preparing the positive electrode film, such as the positive electrode active particles, the positive electrode electrolyte particles, the positive electrode conductive agent, the optional positive electrode binder, and any other components, followed by heating and pressure kneading the mixed material into a dough-like material, hot rolling the dough-like material to form a self-supporting positive electrode sheet, and hot roll-complexing the self-supporting positive electrode sheet with a positive electrode current collector, the self-supporting positive electrode sheet can be complexed to at least one side (single side or double sides) of the positive electrode current collector to obtain the positive electrode film. Non-limitingly, a double planetary mixer can be used for dry mixing. Non-limitingly, an internal mixer can be used for heating and pressure kneading. Non-limitingly, the temperature for hot rolling can be 75-85 °C, further such as 78 °C, 80 °C, 82 °C, etc. The method for assembling a solid-state battery using the positive electrode film can be suitable for industrial batch production. A similar method can be used to prepare a negative electrode film or a negative electrode sheet.

[0307] In some embodiments, the positive electrode film can be prepared by dispersing the above-mentioned components for preparing the positive electrode film, such as the positive electrode active particles, the positive electrode electrolyte particles, the positive electrode conductive agent, the positive electrode binder and any other components, in an organic solvent to form a positive electrode slurry. Further, the positive electrode slurry is coated on at least one side surface of the positive electrode current collector, and after drying, pressing and other processes, the positive electrode film is obtained. The type of the organic solvent in the positive electrode slurry can include one or more of p-xylene, m-xylene, butyl butyrate, heptane and the like, and further can be p-xylene. The positive electrode slurry can be coated on a single surface of the positive electrode current collector, or on both surfaces of the positive electrode current collector. The solid content of the positive electrode slurry can be 40wt% to 80wt%. The viscosity of the positive electrode slurry at room temperature can be adjusted to 5000mPa·s to 25000mPa·s. When the positive electrode slurry is coated, the coating unit area density (single side) by dry weight (excluding solvent) can be 15mg / cm 2 to 35mg / cm 2 . The positive electrode film can have a compacted density of 3.0g / cm 3 to 3.6g / cm 3 , and optionally 3.3g / cm 3 to 3.5g / cm 3 .

[0308] As used herein, "compacted density" has the meaning commonly known in the art as one of the reference indicators of the energy density of a material. In the present application, unless otherwise specified, the compacted density of an electrode layer refers to the ratio of the mass of the electrode active material layer to its volume. The compacted density of a positive electrode layer, positive electrode tab, positive electrode film or positive electrode film refers to the ratio of the mass of the positive electrode active material layer to its volume, and the compacted density of a negative electrode layer, negative electrode tab, negative electrode film or negative electrode film refers to the ratio of the mass of the negative electrode active material layer to its volume.

[0309] The compacted density = the coating area density / the thickness of the electrode active material layer.

[0310] The coating area density = the dry weight of the slurry / the area of the electrode active material layer.

[0311] The double-sided thickness of the electrode active material layer corresponds to the sum of the double-sided coating area density, and the single-sided thickness corresponds to the single-sided coating area density; when the electrode active material layers on both sides of the current collector are substantially the same, the compacted density can be calculated as follows: the compacted density = the single-sided coating area density / the single-sided thickness of the electrode active material layer.

[0312] The "single-sided" and "double-sided" of the electrode active material layer are relative to the position distribution of the current collector.

[0313] The following is some description of the negative electrode film and negative electrode layer.

[0314] In this application, unless otherwise specified, “negative electrode film” refers to a film that can be used as a negative electrode of a solid-state battery, and at least includes a negative electrode active material layer, and can further include a negative electrode current collector.

[0315] The negative electrode layer can be provided by a negative electrode tab or a negative electrode film sheet that is known in the art for use in a solid-state battery, or the constituent materials of the negative electrode layer can be directly pressed into a negative electrode film layer on one side surface of the solid electrolyte layer. The negative electrode film sheet can be combined with other films suitable for a negative electrode to form a negative electrode tab or a negative electrode layer.

[0316] The negative electrode layer can be prepared by a dry method or a wet method. For example, a dry method can be used to press a negative electrode film, which can be a negative electrode film sheet or a negative electrode film layer. For another example, a wet method can be used to coat a negative electrode film, which can be a negative electrode film layer.

[0317] The negative electrode film and the negative electrode layer each include a negative electrode active material layer, and the negative electrode active material layer includes negative electrode active particles containing a negative electrode active substance. Non-limitingly, the negative electrode active material layer can or can not include negative electrode electrolyte particles.

[0318] In some embodiments, the negative electrode active material layer includes negative electrode electrolyte particles, and further, the negative electrode electrolyte particles can include the sulfide solid electrolyte described in the first aspect of the application.

[0319] Non-limitingly, the weight percentage of the negative electrode active particles or the negative electrode active substance in the negative electrode active material layer can be ≥ 80 wt%, and further can be ≥ 90 wt%.

[0320] In some embodiments, the negative electrode active particles or the negative electrode active substance is a lithium-indium alloy (InLi alloy).

[0321] In some embodiments, the negative electrode layer is an InLi alloy film.

[0322] In some embodiments, the negative electrode active substance can also use a negative electrode active substance known in the art for use in a solid-state battery. As a non-limiting example, the negative electrode active substance can include one or more of the following materials: one or more of elemental silicon, elemental tin, a silicon-carbon negative electrode (i.e., a silicon-carbon composite material), silicon monoxide, graphite, metallic lithium. However, the application is not limited to these materials or substances, and other conventional materials that can be used as a battery negative electrode active substance can also be used. These negative electrode active substances can be used alone or in combination with two or more.

[0323] In some embodiments, the negative electrode tab or the negative electrode sheet can include a negative electrode current collector and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector, the negative electrode active material layer including a negative electrode active material. As a non-limiting example, the negative electrode current collector has two surfaces facing away from each other in the thickness direction thereof, and the negative electrode active material layer is disposed on either one or both of the two surfaces of the negative electrode current collector. In some embodiments, the negative electrode current collector can employ a metal foil or a composite current collector. For example, as the metal foil, a copper foil can be employed. In the negative electrode current collector, the composite current collector can include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer. In the negative electrode current collector, the composite current collector can be formed by forming a metal material on the polymer material base layer. In the negative electrode current collector, non-limiting examples of the metal material can include one or more of copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, silver alloy, and the like. In the negative electrode current collector, non-limiting examples of the polymer material base layer can include one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), and the like.

[0324] In some embodiments, the negative electrode active material layer can optionally include a conductive agent, denoted as a negative electrode conductive agent. Non-limitingly, the negative electrode conductive agent can include one or more of super P, acetylene black, carbon black, ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers. In the negative electrode active material layer, the weight percentage of the negative electrode conductive agent can be 0-10 wt%, further optionally 0-5 wt%, more further optionally 0.1-5 wt%, more further optionally 0.1-3 wt%.

[0325] In some embodiments, the negative electrode active material layer can optionally include a binder, denoted as a negative electrode binder. As a non-limiting example, the negative electrode binder can include one or more of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), a vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, a vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, a tetrafluoroethylene-hexafluoropropylene copolymer, and a fluorine-containing acrylic resin. Non-limitingly, the weight percentage of the negative electrode binder in the negative electrode active material layer can be 0-10 wt%, further optionally 0-5 wt%, more further optionally 1-5 wt%, more further optionally 1-3 wt%.

[0326] In some embodiments, the negative active material layer optionally includes other auxiliary agents, such as thickening agents (e.g., sodium carboxymethyl cellulose (CMC-Na)), and the like. The weight percentage of the other auxiliary agents in the negative active material layer can be 0-15 wt%, further optionally 0-10 wt%, more further optionally 0-5 wt%, more further optionally 0-3 wt%, and more further optionally 0-2 wt%.

[0327] In some embodiments, the negative electrode film (which can be used as a negative electrode sheet) can be prepared by dry mixing the components described above for preparing the negative electrode film, such as the negative active particles, the optional negative electrolyte particles, the negative conductive agent, the optional negative binder, and any other components, and then heating and pressure kneading the mixed material into a dough-like material, hot rolling the dough-like material to form a self-supporting negative electrode sheet, and hot roll-complexing the self-supporting negative electrode sheet with a negative current collector, which can be on at least one side (single side or double sides) of the negative current collector, to obtain the negative electrode film. Non-limitingly, a double planetary mixer can be used for the dry mixing. Non-limitingly, a banbury mixer can be used for the heating and pressure kneading. The method for assembling the solid-state battery using the negative electrode film can be suitable for industrial batch production. When the negative electrode material is prepared into a negative active material layer using a dry method, the negative conductive agent can be disposed in the negative electrode material, which can improve the electronic conductivity of the negative active material layer.

[0328] In some embodiments, the negative electrode sheet or the negative electrode film can be prepared by dispersing the components described above for preparing the negative electrode sheet or the negative electrode film, such as the negative active particles, the optional negative electrolyte particles, the negative conductive agent, the negative binder, and any other components, in a solvent (a non-limiting example of the solvent is p-xylene) to form a negative electrode slurry. Further, the negative electrode slurry is coated on at least one side surface of a negative current collector, and after processes such as drying and pressing, the negative electrode sheet or the negative electrode film can be obtained. The surface of the negative current collector coated with the negative electrode slurry can be on a single surface of the negative current collector or on both surfaces of the negative current collector. The solid content of the negative electrode slurry can be 30-70 wt%, optionally 40-60 wt%. The viscosity of the negative electrode slurry at room temperature can be adjusted to 2000-10000 mPa·s, optionally 3000-10000 mPa·s. When the negative electrode slurry is coated, the coating unit area density (single side) can be 1.5-18 mg / cm 2 2 , but not limited thereto. The negative electrode sheet or the negative electrode film can have a compacted density of 1.0-2.0 g / cm 3 3 , optionally 1.0-1.8 g / cm 3 3 .​​​

[0329] Non-limitingly, the positive electrode sheet, the solid electrolyte membrane sheet and the negative electrode sheet can be sequentially stacked, the solid electrolyte membrane sheet is arranged between the positive electrode sheet and the negative electrode sheet, and a solid-state battery cell is prepared by hot rolling.

[0330] Non-limitingly, the positive electrode sheet, the solid electrolyte membrane sheet and the negative electrode sheet can be sequentially stacked, the solid electrolyte membrane sheet is arranged between the positive electrode sheet and the negative electrode sheet, and a solid-state battery cell is prepared by hot rolling.

[0331] In some embodiments, the solid-state battery cell 5 comprises a solid-state battery cell 52.

[0332] In some embodiments, the solid-state battery cell is a full solid-state battery cell.

[0333] In some embodiments, the solid-state battery cell 52 (which can be a full solid-state battery cell) comprises a positive electrode layer 200, a solid electrolyte layer 100 and a negative electrode layer 300 which are sequentially stacked, for example as shown in FIG. 1.

[0334] In some embodiments, the solid-state battery can comprise an outer package. The outer package can be used to package the solid-state battery cell described above.

[0335] In some embodiments, the outer package of the solid-state battery can be a hard shell, such as a hard plastic shell, an aluminum shell, a steel shell, etc. The outer package of the solid-state battery can also be a soft package, such as a pouch soft package. The material of the soft package can be plastic, and further, non-limiting examples of the plastic can include one or more of polypropylene, polybutylene terephthalate, and polybutylene succinate, etc.

[0336] The shape of the solid-state battery cell is not particularly limited in the present application, and it can be cylindrical, square or any other shape. For example, FIG. 2 is a square structure of the solid-state battery cell 5 as an example.

[0337] In some embodiments, referring to FIG. 3, the outer package can comprise a shell 51 and a cover plate 53. The shell 51 can comprise a bottom plate and a side plate connected to the bottom plate, and the bottom plate and the side plate enclose a receiving cavity. The shell 51 has an opening communicating with the receiving cavity, and the cover plate 53 can be arranged on the opening to close the receiving cavity. The solid-state battery cell 52 is packaged in the receiving cavity. The number of solid-state battery cells 52 contained in the solid-state battery cell 5 can be one or more, which can be selected by those skilled in the art according to actual needs.

[0338] The solid-state battery can be a battery module 4 or a battery pack 1.

[0339] The battery module includes at least one solid-state battery cell. The number of solid-state battery cells included in the battery module can be one or more, and a person skilled in the art can select a suitable number according to the application and capacity of the battery module.

[0340] FIG. 4 is a battery module 4 as an example. Referring to FIG. 4, in the battery module 4, a plurality of solid-state battery cells 5 can be arranged in sequence along the length direction of the battery module 4. Of course, other arbitrary arrangements can also be made. Further, the plurality of solid-state battery cells 5 can be fixed by fasteners.

[0341] Optionally, the battery module 4 can also include a housing having an accommodation space, and the plurality of solid-state battery cells 5 are accommodated in the accommodation space.

[0342] In some embodiments, the above-mentioned battery module can also be assembled into a battery pack, and the number of battery modules included in the battery pack can be one or more, and a person skilled in the art can select a suitable number according to the application and capacity of the battery pack.

[0343] FIGS. 5 and 6 are a battery pack 1 as an example. Referring to FIGS. 5 and 6, the battery pack 1 can include a battery box and a plurality of battery modules 4 arranged in the battery box. The battery box includes an upper box body 2 and a lower box body 3, and the upper box body 2 can be arranged on the lower box body 3 and form a closed space for accommodating the battery modules 4. The plurality of battery modules 4 can be arranged in the battery box in any manner.

[0344] In some embodiments, the electric device includes the solid-state battery of any of the embodiments provided in the present application.

[0345] Without limitation, the solid-state battery can be used as a power supply of an electric device, and can also be used as an energy storage unit of an electric device. The electric device can include a mobile device, an electric vehicle, an electric train, a ship and a satellite, an energy storage system, etc., but is not limited thereto. Among them, the mobile device can be a mobile phone, a notebook computer, etc.; the electric vehicle can be a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric bicycle, an electric scooter, an electric golf cart, an electric truck, an electric motorcycle, an electric tool, etc., but is not limited thereto. The electric device can also be applied to military equipment, aerospace, etc., and can also be applied to hydroelectric, thermal, wind and solar power stations, etc. Energy storage power supply systems.

[0346] As an electric device, the solid-state battery can be selected according to the use requirements thereof.

[0347] FIG. 7 is an example of an electric device 6. The electric device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc. To meet the demand of the electric device for high power and high energy density of solid-state batteries, a battery pack or a battery module can be used.

[0348] An example of the device can be a mobile phone, a tablet, a notebook, etc. The device generally requires thinness, and a solid-state battery can be used as a power source.

[0349] Hereinafter, some embodiments of the present application will be described. The embodiments described below are exemplary and are for the purpose of explanation of the present application only, and are not to be understood as a limitation of the present application. In the embodiments, unless otherwise noted, the techniques or conditions are as described above, or as described in the literature in the art, or as described in the product manual. Unless otherwise noted, the reagents or instruments used are conventional products that can be obtained commercially, or can be synthesized from conventional products available commercially in a conventional manner.

[0350] In the following examples, room temperature refers to 20°C to 30°C.

[0351] In each of the following examples, unless otherwise noted, the amount of "sulfur element" expressed in wt% refers to the weight percentage in the sintered mixture; in each of the following preparation examples, unless otherwise noted, the sintered mixture is the precursor mixture; in each of the following comparative examples, unless otherwise noted, the sintered mixture is the raw material mixture.

[0352] It should be noted that in each of the following embodiments and examples, a sulfide all-solid-state battery is used as a non-limiting example of a solid-state battery.

[0353] I. Preparation of a sulfide solid electrolyte

[0354] Preparation Example 1. A precursor mixture was prepared by weighing 2.0 mol of Li2S, 0.475 mol of P2S5, 0.025 mol of Sb2S3, 0.05 mol of S, and 1.5 mol of LiCl raw material powders in stoichiometric ratios of the chemical formula Li 5.5 P 0.95 Sb 0.05 S 4.5 Cl 1.5 A sulfide solid electrolyte powder was obtained by sintering the precursor mixture at 500°C for 8 hours in an atmosphere (argon) furnace, and then crushing the sintered body. The sulfide solid electrolyte powder was a argyrodite-type sulfide solid electrolyte powder.

[0355] Preparation Example 2. A precursor mixture was prepared by weighing 2.0 mol of Li2S, 0.475 mol of P2S5, 0.025 mol of Sb2S3, 0.05 mol of S, and 1.5 mol of LiCl raw material powders in stoichiometric ratios of the chemical formula Li 5.5 P 0.9 Sb 0.1S 4.5 Cl 1.5 stoichiometric ratio, 2.0 mol of Li2S, 0.45 mol of P2S5, 0.05 mol of Sb2S3, 0.1 mol of S and 1.5 mol of LiCl raw material powders were weighed, and 4 wt% of elemental sulfur was further weighed, mixed, and a precursor mixture was obtained. The precursor mixture was sintered at 500°C for 8 hours in an atmosphere (argon) furnace, and then the sintered body was crushed to obtain a powdery argyrodite sulfide solid electrolyte.

[0356] Preparation Example 3. A precursor mixture was prepared according to the stoichiometric ratio of Li 5.5 P 0.8 Sb 0.2 S 4.5 Cl 1.5 stoichiometric ratio, 2.0 mol of Li2S, 0.45 mol of P2S5, 0.05 mol of Sb2S3, 0.1 mol of S and 1.5 mol of LiCl raw material powders were weighed, and 4 wt% of elemental sulfur was further weighed, mixed, and a precursor mixture was obtained. The precursor mixture was sintered at 500°C for 8 hours in an atmosphere (argon) furnace, and then the sintered body was crushed to obtain a powdery argyrodite sulfide solid electrolyte.

[0357] Preparation Example 4. A precursor mixture was prepared according to the stoichiometric ratio of Li 5.4 P 0.9 Sn 0.1 S 4.3 Cl 1.7 stoichiometric ratio, 1.85 mol of Li2S, 0.45 mol of P2S5, 0.1 mol of SnS2 and 1.7 mol of LiCl raw material powders were weighed, and 4 wt% of elemental sulfur was further weighed, mixed, and a precursor mixture was obtained. The precursor mixture was sintered at 460°C for 8 hours in an atmosphere (argon) furnace, and then the sintered body was crushed to obtain a powdery argyrodite sulfide solid electrolyte.

[0358] Preparation Example 5. A precursor mixture was prepared according to the stoichiometric ratio of Li 5.5 P 0.8 Sn 0.2 S 4.3 Cl 1.7 stoichiometric ratio, 1.9 mol of Li2S, 0.4 mol of P2S5, 0.2 mol of SnS2 and 1.7 mol of LiCl raw material powders were weighed, and 4 wt% of elemental sulfur was further weighed, mixed, and a precursor mixture was obtained. The precursor mixture was sintered at 460°C for 8 hours in an atmosphere (argon) furnace, and then the sintered body was crushed to obtain a powdery argyrodite sulfide solid electrolyte.

[0359] Preparation Example 6. A precursor mixture was prepared according to the stoichiometric ratio of Li5.6 P 0.7 Sn 0.3 S 4.3 Cl 1.7 stoichiometric ratio, 1.95 mol of Li2S, 0.35 mol of P2S5, 0.3 mol of SnS2and 1.7 mol of LiCl raw material powders were weighed, and 4 wt% of elemental sulfur was further weighed, mixed, and a precursor mixture was obtained. The precursor mixture was placed in an atmosphere (argon) furnace and sintered at 450°C for 8 hours, and then the sintered body was crushed to obtain a powdery argyrodite sulfide solid electrolyte.

[0360] Preparation Example 7. A powdery argyrodite sulfide solid electrolyte was prepared according to the substantially same method as in Preparation Example 1, except that the target chemical formula and the corresponding raw material stoichiometric ratio were changed. The target chemical formula for controlling the raw material stoichiometric ratio was Li 5.7 P 0.6 Sn 0.4 S 4.3 Cl 1.7 stoichiometric ratio, 1.95 mol of Li2S, 0.35 mol of P2S5, 0.3 mol of SnS2and 1.7 mol of LiCl raw material powders were weighed, and 4 wt% of elemental sulfur was further weighed, mixed, and a precursor mixture was obtained. The precursor mixture was placed in an atmosphere (argon) furnace and sintered at 450°C for 8 hours, and then the sintered body was crushed to obtain a powdery argyrodite sulfide solid electrolyte.

[0361] Preparation Example 8. A powdery argyrodite sulfide solid electrolyte was prepared according to the substantially same method as in Preparation Example 1, except that the target chemical formula and the corresponding raw material stoichiometric ratio were changed. The target chemical formula for controlling the raw material stoichiometric ratio was Li 5.2 P 0.8 Sb 0.1 Sn 0.1 S 4.1 Cl 1.9 stoichiometric ratio, 1.65 mol of Li2S, 0.4 mol of P2S5, 0.1 mol of SnS2, 0.05 mol of Sb2S3, 0.1 mol of S and 1.9 mol of LiCl raw material powders were weighed, and 4 wt% of elemental sulfur was further weighed, mixed, and a precursor mixture was obtained. The precursor mixture was placed in an atmosphere (argon) furnace and sintered at 450°C for 8 hours, and then the sintered body was crushed to obtain a powdery argyrodite sulfide solid electrolyte.

[0362] Preparation Examples 9 to 12. A powdery sulfide solid electrolyte was prepared according to the substantially same method as in Preparation Example 8, except that the target chemical formula and the corresponding raw material stoichiometric ratio were changed. The target chemical formula for controlling the raw material stoichiometric ratio was Li 5.3 P 0.7 Sb 0.1 Sn 0.2 S 4.1 Cl 1.9 (Preparation Example 9, sintering temperature: 450°C), Li 5.5 P 0.4 Sb 0.2Sn 0.4 S 4.1 Cl 1.9 (Preparation Example 10, sintering temperature: 450°C), Li 5.85 P 0.9 Sb 0.05 Sn 0.05 S 4.8 Cl 1.2 (Preparation Example 11, sintering temperature: 530°C), and Li 5.75 P 0.9 Sb 0.05 Sn 0.05 S 4.7 Cl 1.2 (Preparation Example 12, sintering temperature: 530°C), and the sintering temperature can be appropriately adjusted. See Table 1.

[0363] Preparation Example 13. A sulfide solid electrolyte was prepared in substantially the same manner as in Preparation Example 8, except that the Cl element in the target chemical formula was changed to a Br element (sintering temperature: 450°C), the precursor raw material LiCl was replaced by LiBr accordingly, and the sintering temperature can be appropriately adjusted. See Table 1.

[0364] Comparative Example 1. A raw material mixture was prepared by weighing 2.5 mol of Li2S, 0.5 mol of P2S5, and 1 mol of LiCl raw material powders in stoichiometric proportions according to the chemical formula Li6PS5Cl, and further adding 4 wt% of elemental sulfur, and mixing. The raw material mixture was sintered at 550°C for 8 hours in an atmosphere (argon) furnace, and then the sintered body was crushed to obtain a powdery argyrodite-type sulfide solid electrolyte.

[0365] Comparative Example 2. A raw material mixture was prepared by weighing 2.2 mol of Li2S, 0.5 mol of P2S5, and 1.3 mol of LiCl raw material powders in stoichiometric proportions according to the chemical formula Li 5.7 PS 4.7 Cl 1.3 , and further adding 4 wt% of elemental sulfur, and mixing. The raw material mixture was sintered at 530°C for 8 hours in an atmosphere (argon) furnace, and then the sintered body was crushed to obtain a powdery argyrodite-type sulfide solid electrolyte.

[0366] Comparative Example 3. A raw material mixture was prepared by weighing 2.2 mol of Li2S, 0.5 mol of P2S5, and 1.3 mol of LiCl raw material powders in stoichiometric proportions according to the chemical formula Li 5.5 PS 4.5 Cl 1.5stoichiometric ratio, 2.0 mol of Li2S, 0.5 mol of P2S5, and 1.5 mol of LiCl raw material powders were weighed, and 4 wt% of elemental sulfur was further weighed, and the mixture was mixed to obtain a raw material mixture. The raw material mixture was placed in an atmosphere (argon) furnace and sintered at 500°C for 8 hours, and then the sintered body was crushed to obtain a sulfide solid electrolyte powder of argyrodite type.

[0367] Comparative Example 4. According to the chemical formula Li 5.1 PS 4.2 Cl 1.9 stoichiometric ratio, 2.0 mol of Li2S, 0.5 mol of P2S5, and 1.5 mol of LiCl raw material powders were weighed, and 4 wt% of elemental sulfur was further weighed, and the mixture was mixed to obtain a raw material mixture. The raw material mixture was placed in an atmosphere (argon) furnace and sintered at 500°C for 8 hours, and then the sintered body was crushed to obtain a sulfide solid electrolyte powder of argyrodite type.

[0368] Comparative Example 5. Includes M elements, but M elements do not include any of Sb element and Sn element.

[0369] A sulfide solid electrolyte was prepared by substantially the same method as in Preparation Example 2, except that the Sb element in the target chemical formula was changed to a Ge element.

[0370] According to the chemical formula Li 5.5 P 0.9 Ge 0.1 S 4.5 Cl 1.5 stoichiometric ratio, 2.0 mol of Li2S, 0.5 mol of P2S5, and 1.5 mol of LiCl raw material powders were weighed, and 4 wt% of elemental sulfur was further weighed, and the mixture was mixed to obtain a raw material mixture. The raw material mixture was placed in an atmosphere (argon) furnace and sintered at 500°C for 8 hours, and then the sintered body was crushed to obtain a sulfide solid electrolyte powder of argyrodite type.

[0371] In Preparation Examples 1-13, M elements are exemplified by at least one of Sb element and Sn element.

[0372] Table 1. The target chemical formula of the sulfide solid electrolyte prepared in Preparation Examples 1-13 and Comparative Examples 1-5 can be seen in Table 1; the atomic number ratio between the various elements in the argyrodite-type crystal phase calculated from the chemical formula in Table 1 can be seen in Table 2: the atomic number ratio between S element and P element (R S / P ), the atomic number ratio between M element and P element (R M / P ), the atomic number ratio between X element and P element (R X / P ), and the atomic number ratio between Li element and P element (RLi / P ), the atomic number ratio (R Sb / P ), the atomic number ratio (R Sn / S ), the atomic number ratio (R (Sb+Sn) / P ), the atomic number ratio (R Sb / Sn ), and the definitions described above.

[0373] In Comparative Example 5, the atomic number ratio of Ge element to P element is denoted as R Ge / P .

[0374] Table 1. Target chemical formula of sulfide solid electrolytes prepared in Preparation Examples 1-13 and Comparative Examples 1-5

[0375] Table 2.

[0376] In Preparation Examples 1-13, R M / P = R (Sb+Sn) / P , R (Sb+Sn) / P = R Sb / P + R Sn / P , R X / P = R Cl / P .

[0377] In the following examples, unless otherwise specified, the operation or reaction steps involving sulfide solid electrolyte materials as raw materials were carried out in an argon atmosphere.

[0378] In the following examples, unless otherwise specified, the D 811 50 of NCM v 50 was 4 μm, and the D v 50 of sulfide electrolyte Li6PS5Cl was 1 μm.

[0379] In the present application, unless otherwise specified, the D v 50 represents the particle size corresponding to the cumulative volume distribution percentage of 50% of the mixture of multiple particles.

[0380] Test of D v 50:

[0381] In the following examples and comparative examples, the D v 50 of the positive electrode active material and the sulfide solid electrolyte.50Tested and confirmed by the following method: equipment model: MasterSizer 2000 laser particle size analyzer, reference standard procedure: GB / T19077-2016 / ISO 13320:2009, test procedure: take an appropriate amount of sample to be tested (sample concentration is guaranteed to be 8%-12%(w / v) optical density), add 20mL p-xylene (add dispersant ammonium polycarboxylate when testing sulfide solid electrolyte), and simultaneously external ultrasonic for 5min(53KHz / 120W), ensure that the sample is completely dispersed, then determine the sample according to GB / T19077-2016 / ISO 13320:2009 standard.

[0382] II. The solid electrolyte layer is provided with the sulfide solid electrolyte provided in the present application, and the preparation of the solid-state battery (full solid-state secondary battery, sulfide full solid-state battery).

[0383] 1. Preparation of solid electrolyte film (in the form of solid electrolyte film sheet)

[0384] Examples 1-13 (corresponding to sulfide solid electrolyte powders prepared in Preparation Examples 1-13, respectively):

[0385] In an argon atmosphere, the sulfide solid electrolyte powder (prepared in Preparation Examples 1-13) was pressed into a dense solid electrolyte film sheet under the action of 360MPa.

[0386] In an argon atmosphere, the NCM 811 powder, sulfide solid electrolyte Li6PS5Cl, and conductive carbon fiber (VGCF) were manually ground in a mortar for 10min at a weight ratio of 70:28:2 until they were uniformly mixed, obtaining a composite positive electrode powder. The composite positive electrode powder was weighed and uniformly spread on one side surface of the solid electrolyte film sheet, and cold-pressed into a sheet with a pressure of 420MPa and a pressure holding time of 5min, forming a composite film sheet composed of a positive electrode layer and a solid electrolyte layer. An InLi alloy was laminated on the other side of the solid electrolyte film sheet as a negative electrode layer, and a full solid-state battery was assembled, at this time, the solid electrolyte film sheet was used as the solid electrolyte layer, and the positive electrode film sheet was used as the positive electrode layer.

[0387] Comparative Examples 1-5:

[0388] The same method as in Example 1 was used, except that the sulfide solid electrolyte powder used to prepare the solid electrolyte film sheet was replaced with the sulfide solid electrolyte powder prepared in Comparative Examples 1-5.

[0389] III. The positive electrode layer is provided with the sulfide solid electrolyte provided in the present application, and the preparation of the solid-state battery (full solid-state secondary battery, sulfide full solid-state battery).

[0390] Examples P1 to P13 (corresponding to the sulfide solid electrolyte powders of Preparation Examples 1-13, respectively):

[0391] In an argon atmosphere, the positive electrode active particles NCM 811 The powder, the sulfide solid electrolyte powder (obtained by Preparation Examples 1-13 as the positive electrode electrolyte particles), and the conductive carbon fiber (VGCF as the positive electrode conductive agent) were manually ground in a mortar at a weight ratio of 70:28:2 for 10 min until they were uniformly mixed to obtain a composite positive electrode powder.

[0392] In an argon atmosphere, the sulfide solid electrolyte powder Li6PS5Cl was pressed into a dense solid electrolyte film under the action of 360 MPa.

[0393] The composite positive electrode powder was uniformly spread on one side surface of the solid electrolyte film, and cold-pressed into a sheet at a pressure of 420 MPa for 5 min to form a composite film composed of a positive electrode layer and a solid electrolyte layer. An InLi alloy was laminated on the other side of the solid electrolyte film as a negative electrode layer to assemble a full solid-state battery, at this time, the solid electrolyte film was used as a solid electrolyte layer, and the positive electrode film was used as a positive electrode layer.

[0394] Comparative Example P1.

[0395] A full solid-state battery was prepared by substantially the same method as in Example P2, except that the positive electrode electrolyte particles in the composite positive electrode powder were replaced by Li6PS5Cl in Comparative Example 1.

[0396] Four, the negative electrode layer is provided with the sulfide solid electrolyte and the preparation of the solid-state battery (full solid-state secondary battery, sulfide full solid-state battery) provided in the application.

[0397] Examples N1 to N13 (corresponding to the sulfide solid electrolyte powders of Preparation Examples 1-13, respectively):

[0398] In an argon atmosphere, the sulfide solid electrolyte powder Li6PS5Cl was pressed into a dense solid electrolyte film under the action of 360 MPa.

[0399] In an argon atmosphere, the NCM 811 The powder, the sulfide solid electrolyte LiPSCl, and the conductive carbon fiber (VGCF) were manually ground in a mortar at a weight ratio of 70:28:2 for 10 min until they were uniformly mixed to obtain a composite positive electrode powder. The composite positive electrode powder was uniformly spread on one side surface of the solid electrolyte film, and cold-pressed into a sheet at a pressure of 420 MPa for 5 min to form a composite film composed of a positive electrode layer and a solid electrolyte layer.

[0400] Under argon atmosphere, the negative active particle Si powder, sulfide solid electrolyte powder (prepared in Preparation Example 1-13, as negative electrolyte particles) and negative binder PVDF were dispersed in solvent p-xylene (solid content 60wt%) according to weight ratio 80:17:3, and the coating density was 2.5mg / cm2(dry weight basis, excluding solvent) to form a negative electrode slurry. The slurry was coated on the other side of the solid electrolyte layer in the composite membrane, dried to form a negative electrode layer, and a full solid-state battery was obtained, which included a positive electrode layer (corresponding to the positive electrode membrane), a solid electrolyte layer (corresponding to the solid electrolyte membrane), and a negative electrode layer (corresponding to the negative electrode membrane) stacked in sequence. 2 Coated on the other side of the solid electrolyte layer in the composite membrane, dried to form a negative electrode layer, and a full solid-state battery was obtained, which included a positive electrode layer (corresponding to the positive electrode membrane), a solid electrolyte layer (corresponding to the solid electrolyte membrane), and a negative electrode layer (corresponding to the negative electrode membrane) stacked in sequence.

[0401] Comparative Example N1.

[0402] A full solid-state battery was prepared by substantially the same method as in Example N2, except that the negative electrolyte particles in the negative electrode layer were replaced by Li6PS5Cl in Comparative Example 1.

[0403] The preparation parameters and test results of the partial examples and comparative examples in the second, third, and fourth parts can be referred to Table 4.

[0404] V. Test and analysis of materials

[0405] (I) Test and analysis method

[0406] 1. Elemental analysis

[0407] The inductively coupled plasma spectrometer (ICP instrument) was used to analyze the elemental types and proportions of the sulfide solid electrolyte, and determine its chemical formula.

[0408] Test instrument: ThermoFisher ICAP Pro.

[0409] 2. Crystal phase analysis

[0410] The X-ray diffraction (XRD) pattern was used to determine whether the sulfide solid electrolyte included argyrodite-type crystal phase and the amount of impurities.

[0411] Test sample: sulfide solid electrolyte powder.

[0412] Test instrument: Bruker-D8 advance. Cu target Kα1 ray was used, with wavelength λ of 0.15406 nm, X-ray tube controlled at 40 kV and 40 mA, 2θ(°) scanning range of 10°-80°, and 2θ(°) scanning speed of 0.02° / s.

[0413] Analysis method: According to the comparison and analysis of the XRD standard spectrum of Li6PS5Cl, it was confirmed whether the tested sulfide solid electrolyte included argyrodite-type crystal phase.

[0414] 3. Hydrogen sulfide (H2S) release amount test

[0415] Test sample: sulfide solid electrolyte powder

[0416] Test method: 100 mg of the solid electrolyte powder to be tested was evenly spread in a petri dish with a diameter of 5 cm in a dew point environment of -55°C. The petri dish containing the solid electrolyte powder was then placed in a 50 L box through a sealed transfer box. The sealed transfer box containing the solid electrolyte powder was quickly opened in the box, and the 50 L box was sealed. A hydrogen sulfide sensor (PGM-2500) was placed in the box to record the cumulative value of hydrogen sulfide in the 50 L box in real time. The reaction continued until the detection value of the hydrogen sulfide sensor no longer increased, indicating that the electrolyte had completely reacted with the water molecules in the box. A fan with a blade diameter of 8 cm was also placed in the box. Since the density of hydrogen sulfide is greater than that of air, the fan can prevent the hydrogen sulfide gas from settling and ensure uniform distribution of the hydrogen sulfide gas in the 50 L box, thereby improving the reliability of the hydrogen sulfide gas concentration test. Before testing, the 50 L box was placed in an environment with a relative humidity of 70% R.H.

[0417] The sulfide solid electrolyte powders prepared in Preparation Examples 1-13 correspond to Test Examples 1-13, respectively. The sulfide solid electrolyte powders prepared in Comparative Examples 1-5 correspond to Test Comparative Examples 1-5, respectively. The test results can be found in Table 3 “Hydrogen sulfide release amount”.

[0418] 4. Ionic conductivity test

[0419] Ionic conductivity was determined by electrochemical impedance spectroscopy (EIS).

[0420] Test sample: sulfide solid electrolyte powder

[0421] Test sample preparation: 120 mg of the solid electrolyte powder to be tested was poured into a tablet press die with a diameter of 10 mm. The electrolyte powder was pressed into a dense disc at a pressure of 360 MPa to obtain a solid electrolyte membrane as the test sample.

[0422] Test method: The prepared solid electrolyte membrane was clamped in the die with a 10 mm diameter cylindrical stainless steel current collector at a pressure of 120 MPa. The current collector was then connected to an electrochemical workstation. Electrochemical impedance spectroscopy (EIS) was performed on the electrolyte disc at a bias of 10 mV and a frequency range of 10 6 Hz to 10 Hz. The intersection of the curve in the electrochemical impedance spectrum from high frequency to low frequency with the Z' axis was recorded as the resistance R. The ionic conductivity (σ) was calculated by formula (1):

[0423] where d is the thickness of the solid electrolyte membrane, and A is the contact area of the electrolyte disc and the current collector.

[0424] The sulfide solid electrolyte powders prepared in Preparation Examples 1-13 correspond to Test Examples 1-13, respectively; the sulfide solid electrolyte powders prepared in Comparative Examples 1-5 correspond to Test Comparative Examples 1-5, respectively; and the test results can be found in Table 3, “Ionic conductivity”.

[0425] 5. Cycle performance test

[0426] The assembled battery to be tested was first activated by charging and discharging at 0.1C for 3 cycles, and then long cycle test was performed by charging and discharging at 0.33C for 200 cycles, and the cycle capacity retention rate of the battery was calculated. The voltage test window of the battery was 2.8-4.3V vs. Li + vs. Li (lithium potential, active ion is Li + ), and the battery was tested at 25±3°C, wherein 1C=200mA / g. The test results can be found in Table 4, “200 cycle capacity retention rate, 0.33C”.

[0427] (II) Analysis of test results

[0428] 1. Elemental analysis

[0429] ICP test confirmed that the chemical formula of the sulfide solid electrolyte prepared in each of Preparation Examples 1-13 and Comparative Examples 1-5 was basically consistent with the target chemical formula. Taking Example 1 as an example, the target sulfide solid electrolyte Li 5.5 P 0.95 Sb 0.05 S 4.5 Cl 1.5 The actual test results of the elemental composition of Li

[0430] 2. According to the XRD analysis results, the sulfide solid electrolyte prepared in each of Preparation Examples 1-13 and Comparative Examples 1-5 formed a sulfide solid electrolyte. In addition, the impurity phase content of each preparation example was relatively low. As an example, the X-ray diffraction (XRD) pattern of the sulfide solid electrolyte prepared in Preparation Example 8 and Comparative Example 3 can be found in FIG. 8.

[0431] 3. Hydrogen sulfide release amount and ionic conductivity

[0432] The test results of the hydrogen sulfide release amount and ionic conductivity of the sulfide solid electrolyte prepared in each of Preparation Examples 1-13 and Comparative Examples 1-5 can be found in Table 3.

[0433] Compared with Comparative Example 1, the sulfide solid electrolyte of Preparation Examples 1-13 satisfies the following characteristics: (1) the atomic number ratio R M / Pgreater than 0, more specifically, the M element includes at least one of an Sb element and a Sn element; (2) the atomic number ratio R of the X element to the P element is greater than 0 and less than 1; (3) the atomic number ratio R of the S element to the P element is greater than 1 and less than 4.1 X / P >1; (3) the atomic number ratio R of the S element to the P element is greater than 1 and less than 4.1 S / P >4.1. Compared with Comparative Example 1, the sulfide solid electrolyte prepared in each of Preparation Examples 1-13 has a significantly reduced hydrogen sulfide release amount, while also having a good ionic conductivity. In addition, the sulfide solid electrolyte prepared in Preparation Example 12 compared with Comparative Example 2, Preparation Examples 1-3 compared with Comparative Example 3, and Preparation Examples 8-10 compared with Comparative Example 4 also all have a significantly reduced hydrogen sulfide release amount, while also having a good ionic conductivity.

[0434] In each of the preparation examples, a lower hydrogen sulfide release amount indicates that the sulfide solid electrolyte has better chemical stability.

[0435] The sulfide solid electrolyte of Comparative Example 5 was tested for the argyrodite-type crystal phase, which includes the M element, but the M element does not include any of the Sb element and the Sn element, and the M element is Ge. Compared with Test Example 2, the hydrogen sulfide release amount of Comparative Example 5 increased, and the ionic conductivity decreased significantly.

[0436] 4. Cycle performance

[0437] The solid-state batteries prepared in Examples 1-13, Examples P1-P13, and Examples N1-N13 all have good cycle performance. Among them, Examples 1-13 are provided with the sulfide solid electrolyte of the first aspect of the present application in the solid electrolyte layer, Examples P1-P13 are provided with the sulfide solid electrolyte of the first aspect of the present application in the positive electrode layer, and Examples N1-N13 are provided with the sulfide solid electrolyte of the first aspect of the present application in the negative electrode layer.

[0438] For example, compared with Examples 1-13, the cycle performance of Comparative Example 1, which is not provided with the sulfide solid electrolyte of the first aspect of the present application in the solid electrolyte layer, is significantly worse; compared with Examples 12, 3, and 8, the cycle performance of Comparative Examples 2-3, which are not provided with the sulfide solid electrolyte of the first aspect of the present application in the solid electrolyte layer, is significantly worse; compared with Example 2, the cycle performance of Comparative Example 5, which is not provided with the sulfide solid electrolyte of the first aspect of the present application, is significantly worse.

[0439] For example, compared with Example P2, the cycle performance of Comparative Example P1, which is not provided with the sulfide solid electrolyte of the first aspect of the present application in the positive electrode layer, is significantly worse.

[0440] For example, compared with Example N2, the cycle performance of Comparative Example N1, which is not provided with the sulfide solid electrolyte of the first aspect of the present application in the negative electrode layer, is significantly worse.

[0441] Table 3.

[0442] Table 4.

[0443] The above description of various embodiments tends to emphasize differences between various embodiments, and the same or similar parts can be referred to each other, and for the sake of brevity, will not be described herein. The technical features of the above-described embodiments can be combined in any combination, and for the sake of brevity, all possible combinations of the technical features in the above-described embodiments are not described, but as long as the combination of the technical features does not contradict, it should be considered within the scope of the present specification. It should be noted that the present application is not limited to the above-described embodiments. The above-described embodiments are merely examples, and embodiments having substantially the same configuration and playing the same role and effects as the technical idea within the scope of the technical solutions of the present application are included within the technical scope of the present application. The above-described embodiments only express several embodiments of the present application, and the description is relatively detailed, but it should not be construed as limiting the scope of the patent. In addition, within the scope of the gist of the present application, various modifications that can be thought of by those skilled in the art, other modes constructed by combining part of the elements of the embodiments are also included within the scope of the present application.

Claims

1. A sulfide solid electrolyte comprising an argyrodite-type crystal phase; The argyrodite-type crystal phase includes Li element, P element, S element, X element and M element, wherein the X element is a halogen; in, The X element includes one or more elements of Cl and Br, and the M element includes at least one of Sb and Sn; The atomic ratio of the X element to the P element in the argyrodite-type crystal phase is denoted as R X / P , the argyrodite-type crystal phase satisfies R X / P >1; The atomic ratio of S element to P element in the argyrodite crystal phase is denoted as R S / P , the argyrodite-type crystal phase satisfies R S / P >4.

1.

2. The sulfide solid electrolyte according to claim 1, wherein 4.1<R S / P <12.5； Optionally, 4.5≤R S / P ≤12; Further optionally, 4.5≤R S / P ≤10.

25.

3. The sulfide solid electrolyte according to claim 1 or 2, wherein The argyrodite-type crystal phase satisfies one or more of the following characteristics: The atomic ratio of the M element to the P element in the argyrodite-type crystal phase is denoted as R M / P , the argyrodite-type crystal phase satisfies 0 <R M / P ≤1.5, optionally, 0.1≤R M / P ≤1.5; The M element is at least one of Sb and Sn; 1 <R X / P ≤4.75, optionally, 1.3≤R X / P ≤4.7; The X element is at least one of Cl and Br.

4. The sulfide solid electrolyte according to any one of claims 1 to 3, wherein In the argyrodite-type crystal phase, the atomic number ratio of the Li element, the P element, the M element, the S element, and the X element is (6-x+z):(1-yz):(y+z):(5-x):(1+x); wherein, 0<x≤0.9,0≤y≤0.2,0≤z≤0.4,(y+z)> 0.

5. The sulfide solid electrolyte according to any one of claims 1 to 4, wherein In the argyrodite-type crystal phase, the atomic number ratio of the Li element, the P element, the Sb element, the Sn element, the S element and the Cl element is (6-x+z):(1-yz):y:z:(5-x):(1+x); wherein, 0<x≤0.9,0≤y≤0.2,0≤z≤0.4,(y+z)> 0.

6. The sulfide solid electrolyte according to claim 5, wherein The chemical formula of the argyrodite-type crystal phase is Li 6-x+z P 1-y- z M y+z S 5-x X 1+x ; Optionally, the chemical formula of the argyrodite-type crystal phase is Li 6-x+z P 1-y-z Sb y Sn z S 5-x Cl 1+x .

7. The sulfide solid electrolyte according to any one of claims 4 to 6, wherein The argyrodite-type crystal phase satisfies one or more of the following characteristics: x satisfies 0.2≤x≤0.9; y satisfies 0.05≤y≤0.2; z satisfies 0.05≤z≤0.4; y and z satisfy 0.1≤(y+z)≤0.

6.

8. The sulfide solid electrolyte according to any one of claims 1 to 6, which satisfies one or more of the following characteristics: In the argyrodite-type crystal phase, the atomic ratio of Li element to P element is denoted as R Li / P , meeting 5.1 <R Li / P <16, optionally, 6.5≤R Li / P ≤13.7; In the argyrodite-type crystal phase, the atomic ratio of Cl element to P element is denoted as R Cl / P , satisfying 1 <R Cl / P ≤4.75, optionally, 1.3≤R Cl / P ≤4.7; In the argyrodite-type crystal phase, the atomic ratio of Sb element to P element is denoted as R Sb / P , the atomic ratio of Sn element and P element is recorded as R Sn / P , satisfying 0<(R Sb / P +R Sn / P )≤1.5, optionally, 0.1≤(R Sb / P +R Sn / P )≤1.

5.

9. The sulfide solid electrolyte according to any one of claims 1 to 8, wherein In the argyrodite-type crystal phase, the atomic ratio of Sb element to Sn element is denoted as R Sb / Sn , satisfying 0≤R Sb / Sn ≤1, optional 0.5≤R Sb / Sn ≤1.

10. The sulfide solid electrolyte according to any one of claims 1 to 9, wherein The argyrodite-type crystal phase has any of the following chemical formulas: Li 5.5 P 0.9 Sb 0.1 S 4.5 Cl 1.5 、Li 5.6 P 0.7 Sn 0.3 S 4.3 Cl 1.7 He Li 5.2 P 1.8 Sb 0.1 Sn 0.1 S 4.1 Cl 1.9 .

11. The sulfide solid electrolyte according to any one of claims 1 to 10, wherein The 2θ (°) diffraction angle in the X-ray diffraction pattern of the sulfide solid electrolyte has a characteristic peak consistent with the argyrodite-type crystal phase.

12. The sulfide solid electrolyte according to claim 11, which satisfies at least one of the following characteristics: The sulfide solid electrolyte has a 2θ (°) diffraction angle having peaks at 15.5±0.2°, 18.1±0.2°, 25.6±0.2°, 30.1±0.2°, 31.4±0.2°, 39.8±0.2°, 45.1±0.2°, 47.9±0.2°, and 52.5±0.2° in an X-ray diffraction pattern; The X-ray diffraction pattern of the sulfide solid electrolyte is obtained by using Cu Kα radiation; The X-ray diffraction pattern of the sulfide solid electrolyte is obtained by powder X-ray diffraction testing.

13. A method for preparing a sulfide solid electrolyte, comprising the following steps: A precursor mixture comprising Li2S, P2S5, LiX, M source and sulfur element is provided according to the required raw material stoichiometric ratio; wherein, X is a halogen, and X includes one or more elements of Cl and Br; the M source is a raw material for providing the M element, and the M element includes at least one of Sb and Sn; when the sulfide solid electrolyte contains Sb, the precursor mixture also includes Sb2S3; when the sulfide solid electrolyte contains Sn, the precursor mixture includes SnS2; The precursor mixture is sintered in an inert atmosphere to prepare a sulfide solid electrolyte including an argyrodite-type crystal phase; the atomic number ratio of the X element to the P element in the argyrodite-type crystal phase is recorded as R X / P The atomic ratio of S element to P element in the argyrodite-type crystal phase is recorded as R S / P , the argyrodite-type crystal phase satisfies R X / P >1 and R S / P >4.

1.

14. The method for preparing a sulfide solid electrolyte according to claim 13, which satisfies one or more of the following characteristics: The weight ratio of the sulfur element to the precursor mixture is 3.9 wt% to 4.1 wt%; The inert atmosphere is an argon atmosphere; The sintering temperature is 450°C to 530°C; The prepared sulfide solid electrolyte is the sulfide solid electrolyte described in any one of claims 1 to 12.

15. A solid electrolyte membrane comprising at least one of the sulfide solid electrolyte according to any one of claims 1 to 12 and the sulfide solid electrolyte prepared by the preparation method according to claim 13 or 14.

16. An electrode plate, comprising an electrode active material layer, wherein the electrode active material layer comprises an electrode active substance, and further comprises at least one of the sulfide solid electrolyte according to any one of claims 1 to 12 and the sulfide solid electrolyte prepared by the preparation method according to claim 13 or 14.

17. The electrode plate according to claim 16, wherein: The electrode sheet is a positive electrode sheet, the electrode active material layer is referred to as a positive electrode active material layer, and the electrode active substance is referred to as a positive electrode active substance; Alternatively, the electrode plate is a negative electrode plate, the electrode active material layer is recorded as a negative electrode active material layer, and the electrode active substance is recorded as a negative electrode active substance.

18. A solid-state battery comprising at least one of the sulfide solid electrolyte according to any one of claims 1 to 12, the sulfide solid electrolyte prepared by the preparation method according to claim 13 or 14, the solid electrolyte membrane according to claim 15, and the electrode sheet according to claim 16 or 17.

19. The solid-state battery according to claim 18, wherein: The solid-state battery is a sulfide all-solid-state battery.

20. An electrical device comprising at least one of the sulfide solid electrolyte according to any one of claims 1 to 12, the sulfide solid electrolyte prepared by the preparation method according to claim 13 or 14, the solid electrolyte membrane according to claim 15, the electrode plate according to claim 16 or 17, and the solid-state battery according to claim 18 or 19.

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