Solid-state battery and preparation method therefor, oxyhalide electrolyte, and electric device

Abstract

Provided are a solid-state battery and a preparation method therefor, an oxyhalide electrolyte, and an electric device. The solid-state battery comprises a positive electrode active layer, the positive electrode active layer comprises a positive electrode active material and an oxyhalide electrolyte, and the oxyhalide electrolyte has a structure of formula (1): Li1+xM1-x+0.2yM'xO1+xFyX4-2x (1), wherein M comprises a pentavalent metal ion of a Group V metal element, M' comprises a tetravalent metal ion of a Group IV metal element, X is one or more of Cl-, Br- and I-, 0.1≤x≤0.9, and 0.01≤y≤0.3.

Description

Solid-state batteries and their preparation methods, halide oxide electrolytes and electrical devices

[0001] Related applications

[0002] This application claims priority to Chinese Patent Application No. 2024119974108, filed with the Chinese Patent Office on December 31, 2024, entitled "Solid-state battery and preparation method thereof, halide oxide electrolyte and electrical device", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of battery technology, and in particular to a solid-state battery and its preparation method, a halide oxide electrolyte, and an electrical device thereof. Background Technology

[0004] Solid-state batteries use a non-flammable solid electrolyte to replace the organic electrolyte in traditional liquid secondary batteries, significantly improving battery safety and are considered the next generation of batteries closest to industrialization. However, in practical applications, it has been found that the cycle performance of solid-state batteries is not ideal. Summary of the Invention

[0005] To achieve the above objectives, this application provides a solid-state battery with improved cycle performance and a method for preparing the same; in addition, it also provides a halooxide electrolyte and an electrical device.

[0006] A first aspect of this application provides a solid-state battery, including a positive electrode active layer, the positive electrode active layer comprising a positive electrode active material and a halide oxide electrolyte, the halide oxide electrolyte having a structure of formula (1): Li 1+x M 1-x+0.2y M' x O 1+x F y X 4-2x (1);

[0007] Where M includes pentavalent metal ions of Group 5 transition metals, M' includes tetravalent metal ions of Group 4 transition metals, and X is Cl. - ,Br - and I - One or more of the following, 0.1≤x≤0.9, 0.01≤y≤0.3.

[0008] The solid-state battery described in this application has a positive electrode active layer comprising a positive electrode active material and a halide oxide electrolyte. The halide oxide electrolyte enhances the ion conductivity of the positive electrode layer and reduces the interfacial impedance, thereby promoting the charge transfer efficiency between the positive electrode active material and the external environment and the full release of its capacity. The halide oxide electrolyte has a structure of formula (1), and its anion is doped with fluoride ions to X. Since the radius of fluoride ions is small, the lattice structure is more stable after fluoride ion doping, which can improve the water stability of the halide oxide electrolyte to a certain extent. However, fluoride ion doping will also enhance the interaction between the anion framework and lithium ions, which may reduce the ionic conductivity. Therefore, the cation M' is further introduced to replace the position of the central metal element M, which can regulate the distribution and concentration of lithium ions in the structure, effectively change the local framework structure to promote the rapid migration of lithium ions, and thus improve the ionic conductivity. In this way, the ionic conductivity and water stability of the halide oxide electrolyte are improved by the co-doping of fluoride ions and cation M', thereby improving the cycle performance of the solid-state battery.

[0009] In some embodiments, 0.2 ≤ x ≤ 0.5. The doping ratio of M' ions within this range is beneficial for the halide oxide electrolyte to have better structural stability. Therefore, the prepared halide oxide electrolyte has better ionic conductivity and water stability, and the corresponding solid-state battery can achieve better cycle performance and discharge specific capacity.

[0010] In some embodiments, 0.05 ≤ y ≤ 0.15. Within this range, the doping ratio of fluorine ions results in halide oxide electrolytes with superior ionic conductivity and water stability, leading to better cycle performance in the corresponding solid-state batteries.

[0011] In some implementations, M includes Ta 5+ 、Nb 5+ and V 5+ One or more of them.

[0012] In some implementations, M' includes Zr 4+ Hf 4+ and Ti 4+ One or more of them.

[0013] In some embodiments, the halide electrolyte includes Li 1.1 Ta 0.91 Zr 0.1 O 1.1 F 0.05 Cl 3.8 Li 1.1 Ta 0.92 Zr 0.1 O 1.1 F 0.1 Cl3.8 Li 1.1 Ta 0.93 Zr 0.1 O 1.1 F 0.15 Cl 3.8 Li 1.1 Ta 0.94 Zr 0.1 O 1.1 F 0.2 Cl 3.8 Li 1.1 Ta 0.96 Zr 0.1 O 1.1 F 0.3 Cl 3.8 Li 1.2 Ta 0.82 Zr 0.2 O 1.2 F 0.1 Cl 3.6 Li 1.3 Ta 0.72 Zr 0.3 O 1.3 F 0.1 Cl 3.4 Li 1.4 Ta 0.62 Zr 0.4 O 1.4 F 0.1 Cl 3.2 Li 1.6 Ta 0.42 Zr 0.6 O 1.6 F 0.1 Cl 2.8 Li 1.8 Ta 0.22 Zr 0.8 O 1.8 F 0.1 Cl 2.4 Li 1.9 Ta 0.12 Zr 0.9 O 1.9 F 0.1 Cl 2.2 and Li 1.1 Nb 0.92 Zr 0.1 O 1.1 F 0.1 Cl 3.8 One or more of them.

[0014] In some implementations, one or more of the following conditions are met:

[0015] (1) The halide electrolytes include amorphous and crystalline states;

[0016] (2) The particle size Dv50 of the halide oxide electrolyte is 1μm to 20μm;

[0017] (3) The ionic conductivity of the halide electrolyte at 25°C is 1 mS / cm to 12 mS / cm.

[0018] Controlling the particle size Dv50 of the halide oxide electrolyte within this range can better enhance the ion conductivity of the positive electrode layer and reduce the interfacial impedance, thereby better promoting the charge transfer efficiency between the positive electrode active material and the external environment and the full release of its capacity.

[0019] Controlling the ionic conductivity of the halide oxide electrolyte within this range can better enhance the ion conduction capacity of the positive electrode layer and reduce the interfacial impedance, thereby better promoting the charge transfer efficiency between the positive electrode active material and the external environment and the full release of its capacity.

[0020] In some implementations, one or more of the following conditions are met:

[0021] (1) In the positive electrode active layer, the mass content of the positive electrode active material is 55% to 99%;

[0022] (2) In the positive electrode active layer, the mass content of the halide electrolyte is 1% to 40%;

[0023] (3) The particle size Dv50 of the positive electrode active material is 1nm to 50μm, and can be selected as 50nm to 15μm.

[0024] By controlling the mass content of the halide oxide electrolyte within this range, the ion conduction capacity of the halide oxide electrolyte to enhance the positive electrode layer can be effectively utilized.

[0025] In some implementations, one or more of the following conditions are met:

[0026] (1) In the positive electrode active layer, the mass content of the positive electrode active material is 70% to 85%;

[0027] (2) In the positive electrode active layer, the mass content of the halide electrolyte is 15% to 30%.

[0028] Further controlling the mass content of halide oxide electrolyte within this range can more effectively enhance the ion conductivity of the positive electrode layer and reduce the interfacial impedance, thereby improving the cycle performance of solid-state batteries; while also achieving better discharge specific capacity.

[0029] In some embodiments, the positive electrode active layer further includes one or more of a conductive agent and a binder.

[0030] In some implementations, one or more of the following conditions are met:

[0031] (1) The mass content of the conductive agent in the positive electrode active layer is 0.1% to 5%;

[0032] (2) The mass content of the binder in the positive electrode active layer is 0.1% to 5%.

[0033] In some implementations, one or more of the following conditions are met:

[0034] (1) The conductive agent includes one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphite, graphene and carbon nanofibers.

[0035] (2) The adhesive includes one or more of the following: polyvinylidene fluoride, polytetrafluoroethylene, vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, hydrogenated nitrile rubber, styrene-butadiene rubber, polyacrylic acid, sodium polyacrylate, polyacrylamide, polyvinyl alcohol, sodium alginate, polymethacrylic acid, carboxymethyl chitosan and fluorinated acrylate resin.

[0036] In some embodiments, the thickness of the positive electrode active layer is 20 μm to 150 μm.

[0037] In some embodiments, the solid-state battery includes a solid electrolyte layer, which includes a solid electrolyte, and the solid electrolyte includes one or more of sulfide solid electrolytes, halide solid electrolytes, oxide solid electrolytes, and polymer solid electrolytes.

[0038] Optionally, the solid electrolyte includes a sulfide-based solid electrolyte.

[0039] In some embodiments, the solid-state battery is an all-solid-state battery.

[0040] A second aspect of this application provides a method for preparing a solid-state battery, including the step of preparing a positive electrode active layer, which includes the following steps:

[0041] The lithium source, M source, and M' source are mixed according to the stoichiometric ratio required for the halide oxide electrolyte and then sintered to obtain the halide oxide electrolyte; wherein, the lithium source includes one or more of lithium oxide, lithium carbonate, and lithium hydroxide, and the anions of both the M source and the M' source include fluoride ions and X ions; the halide oxide electrolyte has the structure of formula (1): Li1+x M 1-x+0.2y M' x O 1+x F y X 4-2x (1); where M includes pentavalent metal ions of Group 5 subgroup metals, M' includes tetravalent metal ions of Group 4 subgroup metals, and X is Cl. - ,Br - and I - One or more of the following, 0.1≤x≤0.9, 0.01≤y≤0.3;

[0042] The positive electrode active material and the halide electrolyte are mixed to prepare the positive electrode active layer.

[0043] In a third aspect, this application provides a halide oxide electrolyte having a structure of formula (1): Li 1+x M 1-x+0.2y M' x O 1+x F y X 4-2x (1); where M includes pentavalent metal ions of Group 5 subgroup metals, M' includes tetravalent metal ions of Group 4 subgroup metals, and X is Cl. - ,Br - and I - One or more of the following, 0.1≤x≤0.9, 0.01≤y≤0.3.

[0044] In some embodiments, the halide electrolyte is the halide electrolyte in the solid-state battery provided in the first aspect of this application.

[0045] In a fourth aspect, this application provides an electrical device comprising at least one of the solid-state battery provided in the first aspect of this application, a solid-state battery prepared by the preparation method provided in the second aspect of this application, and a halide electrolyte provided in the third aspect of this application.

[0046] The electrical device of this application includes the solid-state battery provided in this application, and therefore has at least the same advantages as the solid-state battery.

[0047] Details of one or more embodiments of this application are set forth in the following drawings and description. Other features, objects, and advantages of this application will become apparent from the specification, drawings, and claims. Attached Figure Description

[0048] To better describe and illustrate the embodiments or examples provided in this application, reference may be made to one or more accompanying drawings. Additional details or examples used to describe the drawings should not be considered as limiting the scope of any of the disclosed applications, the currently described embodiments or examples, or the best mode of conduct of these applications as currently understood. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0049] Figure 1 is a schematic diagram of a solid-state battery cell according to an embodiment of this application.

[0050] Figure 2 is an exploded view of a solid-state battery cell according to an embodiment of this application shown in Figure 1.

[0051] Figure 3 is a schematic diagram of a battery device according to an embodiment of this application.

[0052] Figure 4 is a schematic diagram of a battery pack according to one embodiment of this application.

[0053] Figure 5 is an exploded view of the battery pack of one embodiment of this application shown in Figure 4.

[0054] Figure 6 is a schematic diagram of an electrical device using a solid-state battery as a power source according to an embodiment of this application.

[0055] Figure 7 shows the XRD patterns of the sintered halide electrolyte and the ball-milled electrolyte material of Example 1 of this application.

[0056] Explanation of reference numerals in the attached drawings: 1, battery pack; 2, upper casing; 3, lower casing; 4, battery assembly; 5, solid-state battery cell; 51, casing; 52, solid-state battery cell; 53, cover plate; 6, electrical device. Detailed Implementation

[0057] Hereinafter, some embodiments of this application are described in detail with appropriate reference to the accompanying drawings. However, some unnecessary details may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of actually identical structures may be omitted. This is to avoid making the following description unnecessarily lengthy and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand this application and are not intended to limit the subject matter of the claims.

[0058] The "range" disclosed in this application can be defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of the specific range. Ranges defined in this way can include or exclude endpoints; any endpoint can be independently included or excluded, and they can be arbitrarily combined, meaning 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 specific parameter, it is expected that ranges of 60–110 and 80–120 are also included. Furthermore, if minimum range values ​​1 and 2 are listed, and maximum range values ​​3, 4, and 5 are also listed, then the following ranges are all expected: 1–3, 1–4, 1–5, 2–3, 2–4, and 2–5. In this application, unless otherwise stated, the numerical range "a–b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0" and "5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is described as an integer ≥ 2, it is equivalent to listing integers such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc. For instance, when a parameter is described as an integer selected from "2-10", it is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0059] In this application, the terms "multiple," "various," "multiple items," "several," etc., unless otherwise specified, refer to a quantity greater than or equal to 2. For example, "one or more" means one or more (greater than or equal to) two. It can be understood that when "any number of" items are involved, it refers to any suitable combination of multiple items, that is, a combination of "any number of" items in a manner that does not conflict and enables the implementation of this application.

[0060] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0061] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment or implementation of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments. The term "implementation" as used herein has a similar understanding.

[0062] Those skilled in the art will understand that the order in which the steps are written in the methods of various embodiments or examples does not imply a strict execution order and does not constitute any limitation on the implementation process. The detailed execution order of each step should be determined by its function and possible internal logic. Unless otherwise specified, all steps of this application may be performed sequentially or randomly, but are preferably performed sequentially. For example, if method M includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, method M may also include step (c), meaning that step (c) can be added to method M in any order. For example, method M may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0063] In this application, unless otherwise specified, M (e.g., m1) means that m1 is a non-limiting example of M, and it is understood that M is not limited to m1.

[0064] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it is selected from either "with" or "without." If multiple "options" appear in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "option" is independent. Unless otherwise specified, the descriptions such as "optionally include" and "optionally contain" in this application, taking "optionally include" as an example, mean "may include or not include."

[0065] In this application, unless otherwise specified, the features or solutions corresponding to "and / or" include any one of two or more of the related listed items, as well as any and all combinations of the related listed items. Any and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. For example, "M and / or N" represents the group consisting of M, N, and "a combination of M and N". "Containing M and / or N" can mean "containing M, containing N, and containing both M and N", or "containing M, containing N, or containing both M and N", and can be appropriately understood according to the context.

[0066] The terms “combinations of,” “any combination of,” and “any combination of” used in this article include all suitable combinations of any two or more of the listed items.

[0067] In this document, the term "suitable" in phrases such as "suitable combination," "suitable method," and "any suitable method" refers to the technical solution that enables the implementation of this application.

[0068] In this document, terms such as "preferred," "better," "more suitable," "ideal," "good," and "superior" are merely descriptions of more effective implementation methods or embodiments, and should be understood not to limit the scope of protection of this application. If multiple "preferred" terms appear in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "preferred" term shall be independent.

[0069] In this application, terms such as "further," "even more," "especially," "for example," "as," "example," and "exemplary" are used for descriptive purposes to indicate differences in content, but should not be construed as limiting the scope of protection of this application.

[0070] In this application, the terms "first aspect," "second aspect," "third aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first," "second," "third," etc., serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on quantity.

[0071] In this application, unless otherwise expressly specified and limited, the phrase "above" or "below" the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. In this application, unless otherwise expressly specified and limited, the phrase "above" or "below" the second feature can indicate a horizontal positional relationship, or it can simply indicate the existence of an attachment relationship without specifying a horizontal positional relationship.

[0072] In this application, the term "room temperature" generally refers to 4℃ to 35℃, and may refer to 20℃ ± 5℃. In some embodiments or examples of this application, room temperature refers to 20℃ to 30℃.

[0073] In this application, if the unit for a data range is only followed by the right endpoint, it indicates that the units for the left and right endpoints are the same. For example, 3~5h or 3-5h both mean that the unit for the left endpoint "3" and the right endpoint "5" is h (hours), and both have the same meaning as 3h~5h. Furthermore, similar descriptions of other parameters such as temperature and size are interpreted in the same way.

[0074] In this application, the exemplary descriptions such as "in some implementations (or embodiments)" and "in one implementation (or embodiment)" may cover, but are not limited to, the following meanings: these solutions can be combined with other solutions in a suitable manner to form new technical solutions.

[0075] Unlike traditional liquid batteries where the electrolyte effectively wets the electrode layer, solid-state batteries typically exhibit poor interfacial compatibility between the solid electrolyte layer and the electrode layer. This results in lower ion conductivity of the positive electrode layer, leading to increased battery impedance and suboptimal battery performance, such as cycle life. Therefore, electrolyte particles are generally added to the positive electrode layer to enhance its ion conductivity, reduce interfacial impedance, and promote efficient charge transfer between the positive electrode active material and the external environment, as well as the full release of its capacity.

[0076] In this application, unless otherwise specified, "electrode layer" includes a layer of electrode active material. The electrode layer can be a positive electrode layer or a negative electrode layer, and "electrode active material" in the electrode layer refers to a substance capable of reversibly inserting and extracting active ions.

[0077] Currently, the electrolytes in the positive electrode layer include sulfide electrolytes and halide solid electrolytes. However, sulfide electrolytes are sensitive to air and easily react with water molecules in the air to produce the toxic gas hydrogen sulfide. While halide solid electrolytes do not react with air to release toxic gases and can improve the safety performance of materials, their interaction with moisture in the air can reduce their ion conductivity, leading to a decline in their long-term cycling performance.

[0078] In view of the above problems, according to various embodiments and examples of this application, this application provides a solid-state battery and a method for preparing the same, a halide oxide electrolyte, and an electrical device thereof. This solid-state battery has improved cycle performance.

[0079] Unless otherwise specified, the term "solid-state battery" in this application refers to a battery in which the electrolyte includes a solid electrolyte. Typically, a solid-state battery includes a positive electrode layer, a solid electrolyte layer, and a negative electrode layer. During charging and discharging, active ions repeatedly insert and extract between the positive and negative electrode layers. The solid electrolyte layer acts as a conductor of ions between the positive and negative electrode layers and also isolates them, preventing short circuits. Therefore, a separator, as found in traditional lithium-ion batteries, is not required in solid-state batteries. Solid-state batteries use a non-flammable solid electrolyte instead of the organic electrolyte in traditional liquid lithium-ion batteries, significantly improving battery safety. In addition to enhanced safety, solid-state batteries are better suited for high-energy-density positive and negative electrode materials and reduce system weight, thus facilitating improvements in energy density.

[0080] In this application, unless otherwise specified, "solid electrolyte" refers to an electrolyte material or substance that exists in solid form during the storage and fabrication of solid-state batteries and their components, as well as during the operation of solid-state batteries. This includes, but is not limited to, solid electrolytes existing in solid form at room temperature.

[0081] In this application, unless otherwise specified, "negative electrode active material" refers to a material used in the negative electrode layer that is capable of reversibly inserting and extracting active ions; "positive electrode active material" refers to a material used in the positive electrode layer that is capable of reversibly extracting and inserting active ions. During solid-state battery charging, active ions are extracted from the positive electrode, pass through the solid electrolyte layer, and insert into the negative electrode; conversely, during solid-state battery discharging, active ions are extracted from the negative electrode and insert into the positive electrode. The active ions are not particularly limited or restrictive; they can be lithium ions, in which case a lithium-ion solid-state battery would be used.

[0082] One embodiment of this application provides a solid-state battery, including a positive electrode layer, the positive electrode layer including a positive electrode active layer, the positive electrode active layer including a positive electrode active material and a halide oxide electrolyte, the halide oxide electrolyte having a structure of formula (1): Li 1+x M 1-x+0.2y M' x O 1+x F y X 4-2x (1);

[0083] Where M includes pentavalent metal ions of Group 5 transition metals, M' includes tetravalent metal ions of Group 4 transition metals, and X is Cl. - ,Br - and I - One or more of the following, 0.1≤x≤0.9, 0.01≤y≤0.3.

[0084] The solid-state battery described in this application has a positive electrode active layer comprising a positive electrode active material and a halide oxide electrolyte. The halide oxide electrolyte enhances the ion conductivity of the positive electrode layer and reduces the interfacial impedance, thereby promoting the charge transfer efficiency between the positive electrode active material and the external environment and the full release of its capacity. The halide oxide electrolyte has a structure of formula (1), and its anion is doped with fluoride ions to X. Since the radius of fluoride ions is small, the lattice structure is more stable after fluoride ion doping, which can improve the water stability of the halide oxide electrolyte to a certain extent. However, fluoride ion doping will also enhance the interaction between the anion framework and lithium ions, which may reduce the ionic conductivity. Therefore, the cation M' is further introduced to replace the position of the central metal element M, which can regulate the distribution and concentration of lithium ions in the structure, effectively change the local framework structure to promote the rapid migration of lithium ions, and thus improve the ionic conductivity. In this way, the ionic conductivity and water stability of the halide oxide electrolyte are improved by the co-doping of fluoride ions and cation M', thereby improving the cycle performance of the solid-state battery.

[0085] The fourth group of transition metals includes titanium (Ti), zirconium (Zr), and hafnium (Hf). The fifth group of transition metals includes tantalum (Ta), vanadium (V), and niobium (Nb).

[0086] In some embodiments, M includes Ta 5+ 、Nb 5+ and V 5+ One or more of them. Optionally, M includes Ta. 5+ 、Nb 5+ One or more of them.

[0087] In some embodiments, M' includes Zr 4+ Hf 4+ and Ti 4+ One or more of them.

[0088] Doping with elements such as Zr (M') can broaden the bottleneck size of lithium-ion diffusion and generate new 3D migration pathways, thereby improving the ionic conductivity of halide oxide electrolytes. Zr is a low-cost element that can also reduce the cost of solid-state electrolytes, which is beneficial for large-scale industrial production. Optionally, M' includes Zr. 4+ .

[0089] 0.1 ≤ x ≤ 0.9, where, as an example, the value of x can be 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, or any two of the above values ​​as endpoints. A doping ratio of M' ions within this range is beneficial for the halide oxide electrolyte to have good structural stability. Therefore, the prepared halide oxide electrolyte exhibits superior ionic conductivity and water stability, and the corresponding solid-state battery can achieve better cycle performance.

[0090] Furthermore, 0.2 ≤ x ≤ 0.5. Within this range, the doping ratio of M' ions is beneficial for the halide oxide electrolyte to have better structural stability. Therefore, the prepared halide oxide electrolyte has better ionic conductivity and water stability, and the corresponding solid-state battery can achieve better cycle performance and better discharge specific capacity.

[0091] 0.01 ≤ y ≤ 0.3, where, as an example, the value of y can be 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.08, 0.1, 0.12, 0.15, 0.16, 0.18, 0.2, 0.22, 0.25, 0.26, 0.28, 0.3, or any two of the above values ​​as endpoints. When the doping ratio of fluoride ions is within this range, the resulting halide oxide electrolyte exhibits good ionic conductivity and water stability, and the corresponding solid-state battery can achieve excellent cycle performance.

[0092] Furthermore, 0.05≤y≤0.15, and even further, 0.1≤y≤0.15. Within this range of fluorine ion doping ratio, the prepared halide oxide electrolyte exhibits superior ionic conductivity and water stability, resulting in solid-state batteries with better cycle performance and improved discharge specific capacity.

[0093] In some embodiments, M is Zr 4+ Hf 4+ Ti 4+ and V 4+ One or more of them; z = 4 - 2x. That is, the structure of formula (1); Li 1+x Ta 1-x+0.2y M x O 1+x F y X 4-2x (1).

[0094] As an example, halide oxide electrolytes include Li 1.1 Ta 0.91 Zr 0.1 O 1.1 F 0.05 Cl 3.8 Li 1.1 Ta 0.92 Zr 0.1 O 1.1 F 0.1 Cl 3.8 Li 1.1 Ta 0.93 Zr 0.1 O 1.1 F 0.15 Cl 3.8 Li 1.1 Ta 0.94 Zr 0.1 O 1.1 F 0.2 Cl 3.8 Li 1.1 Ta 0.96 Zr 0.1 O 1.1 F 0.3 Cl 3.8 Li 1.2 Ta 0.82 Zr 0.2 O 1.2 F 0.1 Cl 3.6 Li 1.3 Ta 0.72 Zr 0.3 O 1.3 F 0.1 Cl 3.4 Li 1.4 Ta0.62 Zr 0.4 O 1.4 F 0.1 Cl 3.2 Li 1.6 Ta 0.42 Zr 0.6 O 1.6 F 0.1 Cl 2.8 Li 1.8 Ta 0.22 Zr 0.8 O 1.8 F 0.1 Cl 2.4 Li 1.9 Ta 0.12 Zr 0.9 O 1.9 F 0.1 Cl 2.2 and Li 1.1 Nb 0.92 Zr 0.1 O 1.1 F 0.1 Cl 3.8 One or more of them.

[0095] In some embodiments, the halide oxide electrolyte comprises both amorphous and crystalline states. XRD analysis confirms that the halide oxide electrolyte comprises both amorphous and crystalline states.

[0096] In some embodiments, the particle size Dv50 of the halide oxide electrolyte is 1 μm to 20 μm. As an example, the particle size Dv50 of the halide oxide electrolyte can be 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, or 20 μm, or within a range defined by any two of the above values. Controlling the particle size Dv50 of the halide oxide electrolyte within this range can better enhance the ion conductivity of the positive electrode layer, reduce interfacial impedance, and better promote the charge transfer efficiency between the positive electrode active material and the external environment, as well as the full release of its capacity.

[0097] Dv50 has a well-known meaning in the art and can be tested using methods known in the art. For example, it can be determined using a laser particle size analyzer (such as the Malvern Master Size 3000). Here, Dv50 represents the particle size at which the percentage of particle volume distribution accumulates to 50% based on the particle size distribution, starting from the smallest particle size.

[0098] Particle size distribution can be obtained by the following method: Take a clean beaker, add an appropriate amount of the sample to be tested, and sonicate thoroughly to ensure complete dispersion. The testing instrument is a Malvern 2000 (USA). After the sample is poured into the injection tower, it circulates with the solution to the test optical path system. Under the illumination of the laser beam, the particle size distribution characteristics can be obtained by receiving and measuring the energy distribution of the scattered light (opause: 8-12%). Particle size distribution diagrams are plotted based on the test data.

[0099] In some embodiments, the ionic conductivity of the halide oxide electrolyte is 1 mS / cm to 12 mS / cm. As an example, the ionic conductivity of the halide oxide electrolyte can be 1 mS / cm, 2 mS / cm, 3 mS / cm, 4 mS / cm, 5 mS / cm, 6 mS / cm, 7 mS / cm, 8 mS / cm, 9 mS / cm, 10 mS / cm, 11 mS / cm, or 12 mS / cm, or any two of the above values ​​as endpoints. Controlling the ionic conductivity of the halide oxide electrolyte within this range can better enhance the ion conduction capability of the positive electrode layer, reduce interfacial impedance, and better promote the charge transfer efficiency and full release of the capacity of the positive electrode active material.

[0100] In some embodiments, the positive electrode layer includes a positive electrode current collector, and the positive electrode active layer is disposed on at least one surface of the positive electrode current collector.

[0101] As a non-limiting example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active layer is disposed on either or both of the two opposite surfaces of the positive current collector.

[0102] In some embodiments, the positive electrode current collector may be a metal foil or a composite current collector. For example, aluminum foil may be used as the metal foil. The composite current collector may include a polymer material substrate and a metal layer formed on at least one surface of the polymer material substrate. The composite current collector can be obtained by forming a metal material on the polymer material substrate. Non-limiting examples of the metal material in the positive electrode current collector may include one or more of aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. Non-limiting examples of the polymer material substrate in the positive electrode current collector may include one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE).

[0103] In some embodiments, the positive electrode active material includes one or more of lithium transition metal oxides, lithium-containing phosphates with an olivine structure, and their respective modified compounds; however, this application is not limited to these materials, and other conventional materials that can be used as battery positive electrode active materials may also be used. These positive electrode active materials may be used alone or in combination of two or more. Optionally, the positive electrode active material includes lithium transition metal oxides.

[0104] Examples of lithium transition metal oxides include, but are not limited to, one or more of lithium cobalt oxides (such as LiCoO2), lithium nickel oxides, lithium manganese oxides, lithium nickel cobalt oxides, lithium manganese cobalt oxides, lithium nickel manganese oxides, lithium nickel cobalt manganese oxides, lithium nickel cobalt aluminum oxides, and their modified compounds. Non-limiting examples of lithium phosphates with an olivine structure include, but are not limited to, one or more of lithium iron phosphate, lithium iron phosphate and carbon composites, lithium manganese phosphate, lithium manganese phosphate and carbon composites, lithium manganese iron phosphate, and lithium manganese iron phosphate and carbon composites. Non-limiting examples of lithium cobalt oxides may include LiCoO2; non-limiting examples of lithium nickel oxides may include LiNiO2; non-limiting examples of lithium manganese oxides may include LiMnO2, LiMn2O4, etc.; non-limiting examples of lithium nickel cobalt manganese oxides may include LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 LiNi 0.83 NiCo 0.12 Mn 0.05 O2, etc. Non-limiting examples of lithium nickel cobalt aluminum oxides may include LiNi. 0.80 Co 0.15 Al 0.05 O2. Examples of lithium iron phosphate include LiFePO4 (also known as LFP). Examples of lithium manganese phosphate include LiMnPO4.

[0105] In some embodiments, the particle size Dv50 of the positive electrode active material is 1 nm to 50 μm, and can be selected as 50 nm to 15 μm. As an example, the particle size Dv50 of the positive electrode active material can be 1nm, 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm, 20μm, 25μm, 30μm, 35μm, 40μm, 50μm, or within the range formed by any two of the above point values ​​as end values.

[0106] In some embodiments, the mass content of the positive electrode active material in the positive electrode active layer is 55% to 99%, and can be selected as 70% to 85%. As an example, the mass content of the positive electrode active material in the positive electrode active layer can be 55%, 60%, 70%, 75%, 80%, 85%, 90%, 95%, or 99%, or within the range formed by any two of the above point values ​​as endpoints.

[0107] In some embodiments, the mass content of halide electrolyte in the positive electrode active layer is 1% to 40%. As an example, the mass content of halide electrolyte in the positive electrode active layer can be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, or 40%, or a range formed by any two of the above values ​​as endpoints. By controlling the mass content of halide oxide electrolyte within this range, the halide oxide electrolyte can effectively enhance the ion conductivity of the positive electrode layer and reduce the interfacial impedance, thereby improving the cycle performance of solid-state batteries; at the same time, it can also ensure good discharge specific capacity.

[0108] Optionally, the mass content of halide oxide electrolyte in the positive electrode active layer is 15% to 30%. Further controlling the mass content of halide oxide electrolyte within this range can more effectively enhance the ion conduction capacity of the positive electrode layer and reduce the interfacial impedance, thereby improving the cycle performance of the solid-state battery; while also taking into account better discharge specific capacity.

[0109] In some embodiments, the positive electrode active layer may optionally include a binder. As a non-limiting example, the binder may include one or more of the following: polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), PVDF-tetrafluoroethylene-propylene terpolymer, PVDF-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, hydrogenated nitrile rubber, styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA), carboxymethyl chitosan (CMCS), and fluorinated acrylate resins.

[0110] Furthermore, the mass content of the binder in the positive electrode active layer is 0.1% to 5%. As an example, the mass content of the binder in the positive electrode active layer can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 2%, 3%, 4%, or 5%, or within the range formed by any two of the above values ​​as endpoints.

[0111] In some embodiments, the positive electrode active layer may optionally include a conductive agent. As a non-limiting example, the conductive agent includes one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphite, graphene, and carbon fibers. The carbon fibers include, but are not limited to, vapor-grown carbon fibers. Further, the carbon fibers may be carbon nanofibers.

[0112] Furthermore, the mass content of the conductive agent in the positive electrode active layer is 0 to 5%, for example, 0.1% to 5%. As an example, the mass content of the conductive agent in the positive electrode active layer can be 0, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 2%, 3%, 4%, 5%, or within the range formed by any two of the above values ​​as endpoints.

[0113] In some embodiments, the positive electrode active layer may optionally include a binder. As a non-limiting example, the binder includes one or more of the following: polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), PVDF-tetrafluoroethylene-propylene terpolymer, PVDF-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, hydrogenated nitrile rubber, styrene-butadiene rubber, polyacrylic acid, sodium polyacrylate, polyacrylamide, polyvinyl alcohol, sodium alginate, polymethacrylic acid, carboxymethyl chitosan, and fluorinated acrylate resins.

[0114] Furthermore, the mass content of the binder in the positive electrode active layer is 0 to 5%, for example, 0.1% to 5%. As an example, the mass content of the conductive agent in the positive electrode active layer can be 0, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 2%, 3%, 4%, or 5%, or within the range formed by any two of the above values ​​as endpoints.

[0115] In some embodiments, the thickness of the positive electrode active layer is 20 μm to 150 μm. As an example, the thickness of the positive electrode active layer can be 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, or 150 μm, or within the range defined by any two of the above values ​​as endpoints.

[0116] An embodiment of this application also provides a halide oxide electrolyte of the above formula (1) and a method for preparing the same, as well as a method for preparing a positive electrode layer containing the halide oxide electrolyte of the above formula (1).

[0117] The preparation method of the halide oxide electrolyte includes the following steps: mixing lithium source, M source and M' source according to the required stoichiometric ratio of halide oxide electrolyte and then sintering to obtain halide oxide electrolyte; wherein, the lithium source includes one or more of lithium oxide, lithium carbonate and lithium hydroxide, and the anions of both M source and M' source include fluoride ions and X ions.

[0118] The inclusion of fluoride ions and X ions in the anions of both M source and M' source means that the anions of both sources as a whole include fluoride ions and X ions. This can mean that one of the M source and M' source contains fluoride ions and the other contains X ions; or it can mean that one of the sources contains both fluoride ions and X ions, while the other is not restricted.

[0119] The M source includes the aforementioned M metal ions. For example, it may include, but is not limited to, one or more of tantalum pentachloride, tantalum pentafluoride, niobium pentafluoride, and niobium pentachloride.

[0120] The M' source includes the aforementioned M' metal ions, which, as an example, may include, but are not limited to, one or more of zirconium tetrachloride, hafnium tetrachloride, and titanium tetrachloride.

[0121] In some embodiments, mixing may be performed using ball milling, which may be carried out using zirconia ball milling media. Further, the mixing speed is 500 rpm, and the mixing time is 16 hours. Further, mixing is carried out in an inert atmosphere.

[0122] In some embodiments, the sintering process is carried out in a protective gas atmosphere, such as argon. In some embodiments, the sintering temperature is 250°C; in some embodiments, the sintering time is 8 hours.

[0123] After obtaining the above-mentioned halide oxide electrolyte, the positive electrode active material and the halide oxide electrolyte are mixed to prepare the positive electrode active layer of the positive electrode layer. Furthermore, the method for preparing the positive electrode active layer of the positive electrode layer can be either a dry method or a wet method.

[0124] The dry method involves directly mixing the positive electrode active material and the halide oxide electrolyte in a solid state without adding a solvent, and then forming a film layer by pressing. As an example, the components used to prepare the positive electrode sheet, such as the positive electrode active material, the halide oxide electrolyte conductive agent, the binder, and any other components, are dry-mixed. The mixed material is then heated and pressurized to form a clump, which is then pressed using methods such as hot rolling to form a self-supporting positive electrode sheet (i.e., the positive electrode active layer). Non-limitingly, a dual planetary mixer can be used for dry mixing. Non-limitingly, a kneading machine can be used for heated and pressurized kneading. Non-limitingly, the temperature for hot rolling can be 75°C to 85°C, and further, such as 78°C, 80°C, 82°C, etc. The method of assembling solid-state batteries using positive electrode sheets is suitable for industrial mass production.

[0125] Furthermore, the self-supporting positive electrode sheet can be combined with the positive current collector hot roller. The self-supporting positive electrode sheet can be combined with at least one side (single or double sides) of the positive current collector to obtain the positive electrode sheet.

[0126] The wet process involves mixing the positive electrode active material and halide electrolyte with a binder, conductive agent, dispersant, and solvent, then coating the mixture onto at least one side of the positive electrode current collector. After drying and cold pressing, the positive electrode sheet is obtained. The solvent used is a low-polarity solvent, including but not limited to one or more of p-xylene, n-heptane, butyl butyrate, and isobutyl isobutyrate.

[0127] In some embodiments, the positive electrode sheet can be prepared by dispersing the components used to prepare the positive electrode sheet, such as the positive electrode active material, conductive agent, binder, and any other components, in an organic solvent to form a positive electrode slurry. Further, the positive electrode slurry is coated onto at least one surface of the positive electrode current collector, and after drying, cold pressing, and other processes, the positive electrode sheet is obtained. Cold pressing can be performed using a cold rolling mill. Non-limitingly, the organic solvent in the positive electrode slurry may include one or more of p-xylene, n-heptane, butyl butyrate, isobutyl isobutyrate, etc. The surface of the positive electrode current collector coated with the positive electrode slurry can be a single surface of the positive electrode current collector or both surfaces of the positive electrode current collector.

[0128] The negative electrode layer can be provided by a pre-fabricated negative electrode sheet, which can be a negative electrode sheet that can be used in solid-state batteries in this field, or it can be directly formed into a negative electrode active layer film by dry pressing and then combined with a negative electrode current collector.

[0129] The negative electrode sheet can be prepared by wet process. Wet coating can be used to form a film.

[0130] In this application, unless otherwise specified, the negative electrode layer includes at least a negative electrode active layer.

[0131] In this application, unless otherwise stated, the negative electrode sheet includes at least a negative electrode active layer.

[0132] Unless otherwise stated in this application, the negative electrode active layer includes at least a negative electrode active material.

[0133] In some embodiments, the negative electrode sheet may include a negative current collector and a negative active layer disposed on at least one surface of the negative current collector, the negative active layer comprising a negative active material.

[0134] In some embodiments, the negative electrode sheet includes a negative electrode active layer, which includes a negative electrode active material.

[0135] Without limitation, the mass content of the negative electrode active material in the negative electrode active layer can be ≥80%, and more specifically 80% to 99%. As an example, the weight content of the negative electrode active material in the negative electrode active layer can be 80%, 85%, 90%, 95%, 99%, or within the range defined by any two of the above points as endpoints.

[0136] As a non-limiting example, the negative electrode current collector has two surfaces that are opposite to each other in its own thickness direction, and the negative electrode active layer is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0137] In some embodiments, the negative electrode current collector may be a metal foil or a composite current collector. For example, copper foil may be used as the metal foil. In the negative electrode current collector, the composite current collector may include a polymer material substrate and a metal layer formed on at least one surface of the polymer material substrate. In the negative electrode current collector, the composite current collector may be formed by forming a metal material on the polymer material substrate. Non-limiting examples of the metal material in the negative electrode current collector may include one or more of copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. Non-limiting examples of the polymer material substrate in the negative electrode current collector may include one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE).

[0138] In some embodiments, the negative electrode active material is a lithium-indium alloy (InLi alloy). In some embodiments, the negative electrode layer or negative electrode sheet is an InLi alloy film.

[0139] In other embodiments, as a non-limiting example, the negative electrode active material may include one or more of the following materials: elemental silicon, elemental tin, silicon-carbon negative electrode composite material, silicon suboxide, graphite, and metallic lithium. However, this application is not limited to these materials or substances, and other conventional materials that can be used as battery negative electrode active materials may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0140] In some embodiments, the negative electrode active layer optionally includes a conductive agent. Non-limitingly, the conductive agent in the negative electrode active layer may include one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphite, graphene, and carbon fibers. The carbon fibers include, but are not limited to, vapor-grown carbon fibers. Further, the carbon fibers may be carbon nanofibers.

[0141] Non-limiting, the mass content of the conductive agent in the negative electrode active layer can be 0-15%, further preferably 0-10%, and even more preferably 0-5%.

[0142] In some embodiments, the negative electrode active layer may optionally include a binder. As a non-limiting example, the binder in the negative electrode active layer may include one or more of polyvinylidene fluoride (PVDF), styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA), and carboxymethyl chitosan (CMCS).

[0143] Non-limitingly, the mass content of the binder in the negative electrode active layer can be 0% to 10%, more preferably 0.1% to 10%, and optionally 1% to 3%. As an example, the mass content of the conductive agent in the negative electrode active layer can be 0.1%, 0.2%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or within the range defined by any two of the above values ​​as endpoints.

[0144] In some embodiments, the negative electrode active layer may optionally include other additives, such as thickeners (e.g., sodium carboxymethyl cellulose (CMC-Na)). The mass content of the other additives in the negative electrode active layer may be 0-15%, more preferably 0-10%, even more preferably 0-5%, even more preferably 0-3%, and even more preferably 0-2%.

[0145] Non-limitingly, the negative electrode active layer may include a solid electrolyte. The solid electrolyte in the negative electrode active layer can enhance the ion conductivity of the negative electrode layer, reduce interfacial impedance, and promote the charge transfer efficiency and full release of the capacity of the negative electrode active material with the external environment.

[0146] Non-limitingly, the mass content of the solid electrolyte in the negative electrode active layer can be 0% to 30%, preferably 0.1% to 30%, and further preferably 5% to 20%.

[0147] The type of solid electrolyte in the negative electrode active layer can be the same as the range of solid electrolytes selected in the solid electrolyte layer described below.

[0148] In some embodiments, the negative electrode sheet can be prepared by dispersing the components used to prepare the negative electrode sheet, such as the negative electrode active material, negative electrode conductive agent, negative electrode binder, and any other components, in a solvent (a non-limiting example of a solvent is p-xylene) to form a negative electrode slurry. Further, the negative electrode slurry is coated onto at least one surface of the negative electrode current collector, and after drying, cold pressing, and other processes, the negative electrode sheet is obtained. Cold pressing can be performed using a cold rolling mill. The surface of the negative electrode current collector coated with the negative electrode slurry can be a single surface of the negative electrode current collector or both surfaces of the negative electrode current collector.

[0149] In some embodiments, the negative electrode layer or negative electrode sheet is an InLi alloy film. The InLi alloy film can be prepared by forming In powder onto a lithium sheet by pressing. Further, the thickness of the lithium sheet is 6μm to 10μm. As an example, the thickness can be 6μm, 7μm, 8μm, 9μm, 10μm, or any two of the above values ​​as end values.

[0150] In some embodiments, the solid-state battery includes a solid electrolyte layer. The electrolyte exists in the form of a solid electrolyte layer, specifically, the solid electrolyte layer is located between the negative electrode layer and the positive electrode layer in the solid-state battery. The solid electrolyte layer serves to conduct ions between the positive and negative electrode layers and can also isolate the positive and negative electrode layers to prevent short circuits between the positive and negative electrodes.

[0151] A solid electrolyte layer can be introduced by forming electrode layers on both sides of the solid electrolyte membrane, or it can be introduced on the electrode layer.

[0152] It is understood that the solid electrolyte layer includes a solid electrolyte. The solid electrolyte in the solid electrolyte layer can be a solid electrolyte known in the art that can be used in solid-state batteries.

[0153] Further, the solid electrolyte includes one or more of sulfide-based solid electrolytes, halide-based solid electrolytes, oxide-based solid electrolytes, and polymer-based solid electrolytes.

[0154] Optionally, the solid electrolyte includes a sulfide-based solid electrolyte.

[0155] In some embodiments, the sulfide electrolyte includes one or more of thioargentite-type sulfide electrolytes, LGPS-type sulfide electrolytes, and lithium sulfide - diphosphorus pentasulfide complex-type sulfide electrolytes.

[0156] Among them, the thioargentite-type sulfide electrolyte includes a sulfide electrolyte with the chemical formula Li 6±s P 1-j A j S 5±s-t B t X 1±s where 0 ≤ s < 1, 0 ≤ j < 1, 0 ≤ t < 1, A includes one or more elements of Ge, Si, Sn, and Sb, B includes one or more elements of O, Se, and Te, and X includes one or more elements of Cl, Br, I, and F. Among them, the LGPS-type sulfide electrolyte includes a sulfide electrolyte with the chemical formula Li 10±δ5 Ge 1-g G g P 2-q Q q S 12-w W w where 0 ≤ δ5 <​​​​​​​​​​​​​​​​​​One or more of the following.

[0159] Non-limiting examples of oxide solid electrolytes may include LISICON-type oxide electrolytes (such as γ-Li3PO4, etc.) and NASICON-type oxide electrolytes (such as Li...). 1+x Al x Ge 2-x (PO4)3,Li 1+x Al x Ti 2-x (PO4)3, etc., 0≤x≤1), Garnet type (such as Li7La3Zr2O12, etc.), perovskite type oxide electrolytes (such as Li 3x La 2 / 3-x One or more of TiO3, etc. (0≤x≤0.5), etc.

[0160] As a non-limiting example, halide solid electrolytes may include one or more of Li3InCl6, Li3YCl6, Li3ScCl6, Li3ErCl6, Li2ZrCl6, etc.

[0161] The solid electrolyte layer can be prepared using a dry method. In some embodiments, the solid electrolyte layer can be formed by pressing a solid electrolyte material into a solid electrolyte membrane. In other embodiments, the solid electrolyte layer is formed by pressing the constituent raw materials of the solid electrolyte layer onto an electrode layer. In still other embodiments, the solid electrolyte membrane can also be prepared using methods such as fibrosis combined with calendering, melt extrusion, or spraying.

[0162] In this application, the sheet-like solid electrolyte membrane may also be referred to as a solid electrolyte membrane sheet.

[0163] Solid electrolyte layers can also be prepared using a wet process. The electrolyte slurry used includes at least a solid electrolyte and an organic solvent, and usually also includes one or more of a binder and a dispersant.

[0164] In some embodiments, the thickness of the solid electrolyte layer can be 0.1 μm to 1000 μm, and can be selected as 10 μm to 100 μm, 100 μm to 800 μm, 500 μm to 800 μm, etc.

[0165] In some implementations, the solid-state battery is an all-solid-state battery.

[0166] In this application, unless otherwise specified, "all-solid-state battery" refers to a solid-state battery in which all electrolytes are solid electrolytes. In this case, the positive electrode layer, negative electrode layer and electrolyte part are all made of solid materials, and no liquid electrolyte is provided in the battery, so it can be called "all-solid-state battery".

[0167] A solid-state battery includes at least one solid-state battery cell. A solid-state battery may include one or more solid-state battery cells.

[0168] In this application, unless otherwise specified, "solid-state battery cell" refers to a basic unit capable of converting chemical energy into electrical energy, and all its components are solid-state. In some embodiments, a solid-state battery cell may be an all-solid-state battery cell.

[0169] In this application, unless otherwise specified, "all-solid-state battery cell" refers to a solid-state battery cell in which all electrolytes are solid electrolytes. In this case, the positive electrode layer, negative electrode layer and electrolyte part are all made of solid materials, and no liquid electrolyte is provided in the battery cell, so it can be called "all-solid-state battery cell".

[0170] Non-limitingly, a solid-state battery cell (which can be an all-solid-state battery cell) may include a positive electrode layer, a solid electrolyte layer, and a negative electrode layer, with the solid electrolyte layer located between the positive and negative electrode layers. During battery charging and discharging, active ions shuttle between the positive and negative electrode layers, inserting and extracting. The solid electrolyte layer serves to conduct ions between the positive and negative electrode layers and also isolates them, thus preventing short circuits between the positive and negative electrodes.

[0171] Another embodiment of this application provides a method for preparing a solid-state battery, including the steps of preparing the positive electrode active layer described above.

[0172] In some embodiments, a positive electrode active layer can be formed on a positive electrode current collector to obtain a positive electrode sheet. A solid-state battery can be assembled in the form of a positive electrode sheet. Alternatively, the positive electrode active layer can be used as a self-supporting film layer and laminated with other film layers, or the positive electrode layer material and negative electrode layer material can be directly laid on both sides of a solid electrolyte membrane and rolled to obtain a solid-state battery cell.

[0173] The positive electrode layer material includes materials used to form the positive electrode active layer, which includes a positive electrode active material and a halide electrolyte. For example, the positive electrode active material is mixed with other components such as a halide electrolyte and a conductive agent to obtain the positive electrode layer material.

[0174] The negative electrode layer material includes materials used to form the negative electrode active layer, which includes negative electrode active materials. For example, the negative electrode active material is mixed with other components such as solid electrolyte, conductive agent, and binder to obtain the negative electrode layer material.

[0175] In other embodiments, without limitation, the positive electrode, the solid electrolyte membrane, and the negative electrode can be stacked sequentially, with the solid electrolyte membrane placed between the positive and negative electrodes, and a solid-state battery cell can be prepared by roll forming.

[0176] In other embodiments, without limitation, the positive electrode layer, the solid electrolyte layer, and the negative electrode layer can be assembled in a stacked manner, with the solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer.

[0177] The rolling process can be either cold rolling or hot rolling. A non-limiting example of a temperature for hot rolling is 180°C.

[0178] In another aspect, this application also provides an electrical device, including at least one of the solid-state battery described above, the negative electrode sheet described above, and the negative electrode sheet prepared by the preparation method described above.

[0179] The solid-state battery and power device of this application will be described below with appropriate reference to the accompanying drawings.

[0180] This application does not impose any particular limitation on the shape of the solid-state battery cell; it can be cylindrical, square, or any other arbitrary shape. For example, Figure 1 shows a square solid-state battery cell 5 as an example.

[0181] In some embodiments, the solid-state battery cell 5 includes a solid-state cell 52.

[0182] In some implementations, the solid-state cell is an all-solid-state cell.

[0183] In some embodiments, the solid-state cell 52 (which may be an all-solid-state cell) includes a positive electrode layer, a solid electrolyte layer, and a negative electrode layer stacked sequentially.

[0184] In some embodiments, the solid-state battery may include an outer packaging. This outer packaging can be used to encapsulate the aforementioned solid-state battery cell.

[0185] In some embodiments, the outer packaging of a solid-state battery can be a rigid shell, such as a hard plastic shell, an aluminum shell, or a steel shell. The outer packaging of a solid-state battery can also be a soft pack, such as a pouch-type soft pack. The material of the soft pack can be plastic; further, non-limiting examples of plastics may include one or more of polypropylene, polybutylene terephthalate, and polybutylene succinate.

[0186] In some embodiments, referring to FIG2, the outer packaging may include a housing 51 and a cover plate 53. The housing 51 may include a base plate and side plates connected to the base plate, the base plate and side plates forming a receiving cavity. The housing 51 has an opening communicating with the receiving cavity, and the cover plate 53 can be placed over the opening to close the receiving cavity. A solid-state battery cell 52 is encapsulated within the receiving cavity. The number of solid-state battery cells 52 contained in the solid-state battery cell 5 may be one or more, which can be selected by those skilled in the art according to actual needs.

[0187] Solid-state batteries can be battery device 4 or battery pack 1.

[0188] The battery device includes at least one solid-state battery cell. The number of solid-state battery cells in the battery device can be one or more, and those skilled in the art can select an appropriate number according to the application and capacity of the battery device.

[0189] Figure 3 shows a battery device 4 as an example. Referring to Figure 3, in the battery device 4, multiple solid-state battery cells 5 can be arranged sequentially along the length of the battery device 4. Of course, they can also be arranged in any other arbitrary manner. Furthermore, the multiple solid-state battery cells 5 can be fixed in place by fasteners.

[0190] Optionally, the battery device 4 may also include a housing with a receiving space in which a plurality of solid-state battery cells 5 are housed.

[0191] In some embodiments, the battery devices described above can also be assembled into a battery pack, and the number of battery devices contained in the battery pack can be one or more. Those skilled in the art can select an appropriate number according to the application and capacity of the battery pack.

[0192] Figures 4 and 5 show a battery pack 1 as an example. Referring to Figures 4 and 5, the battery pack 1 may include a battery compartment and multiple battery devices 4 disposed within the battery compartment. The battery compartment includes an upper compartment 2 and a lower compartment 3, the upper compartment 2 covering the lower compartment 3 to form a closed space for accommodating the battery devices 4. The multiple battery devices 4 can be arranged in any manner within the battery compartment.

[0193] In some embodiments, multiple battery cells 5 can also be arranged in any way in the battery box to directly obtain a solid-state battery.

[0194] This application also provides an electrical device comprising at least one of the solid-state battery described in the first aspect of this application, the negative electrode or solid-state battery described in the second aspect of this application, and the negative electrode or solid-state battery prepared by the above-described preparation method of this application.

[0195] In some embodiments, the electrical device includes at least one of the solid-state batteries of any of the embodiments provided in this application.

[0196] In a non-limiting sense, solid-state batteries can be used as a power source for electrical devices or as an energy storage unit for electrical devices. Electrical devices can include, but are not limited to, mobile devices, electric vehicles, electric trains, ships and satellites, energy storage systems, etc. Mobile devices can be, for example, mobile phones, laptops, etc.; electric vehicles can be, for example, pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, electric motorcycles, power tools, etc., but are not limited to these. This electrical device can also be applied to military equipment, aerospace, and other fields, and can also be applied to energy storage power systems such as hydroelectric, thermal, wind, and solar power plants.

[0197] As an electrical device, solid-state batteries can be selected based on its usage requirements.

[0198] Figure 6 shows an example of an electrical device 6. This electrical device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc. To meet the high power and high energy density requirements of this electrical device for solid-state batteries, a battery device or battery pack can be used as the power source.

[0199] Another example device could be a mobile phone, tablet, or laptop. These devices typically require a thin and light design and can use solid-state battery cells as their power source.

[0200] To make the technical problems, technical solutions, and beneficial effects solved by this application clearer, the application will be further described in detail below with reference to embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this application or its applications. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0201] Where specific techniques or conditions are not specified in the examples, they shall be performed in accordance with the techniques or conditions described in the literature in this field or in accordance with the product instructions. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0202] Example 1

[0203] 1. Synthesis of solid electrolyte. Raw materials were weighed according to a molar ratio of lithium hydroxide: tantalum pentachloride: zirconium tetrachloride: tantalum pentafluoride of 1.1:0.9:0.1:0.02. The mixture was thoroughly mixed in an inert atmosphere glove box, then placed in an 80 mL zirconium oxide ball mill jar and milled at 500 rpm for 16 hours. After milling, the electrolyte material was scraped off. Simultaneously, the ball-milled electrolyte material was sintered at 250 °C for 8 hours under an argon atmosphere to obtain a sintered halide oxide electrolyte, the composition of which is shown in Table 1.

[0204] 2. Preparation of the positive electrode layer material. The positive electrode active material LiNi... 0.83 NiCo 0.12 Mn 0.05 O2 (Dv50 is 4μm), halide oxide electrolyte obtained from sintering in step 1 (Dv50 is 2μm) and VGCF were weighed in a ratio of 70:28:2 and ground in a mortar for 30 minutes until uniform, to obtain a positive electrode layer material with a thickness of 80 micrometers.

[0205] 3. Negative electrode layer material: 100mg In powder and lithium sheet (lithium sheet thickness is 8μm).

[0206] 4. Preparation of solid electrolyte layer. Weigh 120 mg of sulfide electrolyte Li6PS5Cl (LPSCl), add it to the battery mold, and apply pressure at 350 MPa to obtain a solid electrolyte membrane with a thickness of 1 μm.

[0207] 5. Battery assembly.

[0208] A solid electrolyte membrane is placed in a battery mold, and positive and negative electrode materials are respectively laid on both sides of the solid electrolyte membrane. The mixture is then rolled to obtain a solid-state battery cell. 100 mg of In powder is placed between the solid electrolyte membrane and the lithium sheet.

[0209] 6. Performance testing.

[0210] 6.1 XRD detection.

[0211] The X-ray diffractometer used in this experiment was a D8 ADVANCE, and the radiation source was Cu. The detection results are shown in Figure 7. The objects were the sintered halide oxide electrolyte from Example 1 and the electrolyte material obtained by ball milling.

[0212] The XRD patterns of the sintered halide electrolyte and the ball-milled electrolyte material from Example 1 are shown as curves a and b in Figure 7, respectively. The horizontal axis represents 2θ, and the vertical axis represents intensity.

[0213] It can be seen that the curve before sintering is amorphous (non-morphic) and the halide oxide electrolyte after sintering is a combination phase material of amorphous and crystalline states.

[0214] 6.2 Initial ionic conductivity and ionic conductivity after 2 hours of exposure of the halide oxide electrolyte synthesized in step 1.

[0215] The initial ionic conductivity of the halide oxide electrolyte synthesized in step 1 was tested as follows:

[0216] 120 mg of solid electrolyte powder was poured into a 10 mm diameter tableting mold and pressed into a dense disc at 350 MPa. Then, a 10 mm diameter cylindrical stainless steel current collector was used to clamp the solid electrolyte disc within the mold at 120 MPa. The current collector was then connected to an electrochemical workstation with a bias voltage of 10 mV and a frequency range of 10 Hz to 10 Hz. 6 Electrochemical impedance spectroscopy (EIS) was performed on the electrolyte sheet in the range of Hz. The intersection of the curve in the electrochemical impedance spectrum from the high frequency band to the low frequency band with the Z' axis was recorded as the resistance value R. The ionic conductivity can be calculated by formula (1): σ=1 / R·d / A (1);

[0217] Where d is the thickness of the electrolyte sheet in cm; A is the contact area between the electrolyte sheet and the current collector in cm². 2 σ is the ionic conductivity, with units of S / cm.

[0218] The ionic conductivity test after 2 hours of exposure was conducted in a low dew point environment at -40℃, with other test procedures as described above. By comparing the ionic conductivity after 2 hours of exposure with the initial ionic conductivity, the water resistance stability of the halide oxide electrolyte can be determined. A smaller rate of ionic conductivity decay indicates better water resistance stability of the halide oxide electrolyte.

[0219] The decay rate of ionic conductivity = (initial ionic conductivity - ionic conductivity after 2 hours of exposure) / initial ionic conductivity.

[0220] 6.3 Discharge capacity and cycle performance testing.

[0221] At 25°C, the solid-state battery cells were first charged to 4.3V (vs. Li) at a current density of 0.1C. + / Li), let stand for 10 minutes, then discharge at a current density of 0.1C to 2V (vs. Li). + / Li), cycle charge and discharge 5 times, the discharge capacity at this time is recorded as C1, the discharge specific capacity at 0.1C rate = C1 / mass of positive electrode active material;

[0222] The solid-state battery cells were then charged to 4.3V (vs. Li) at a current density of 0.33C. + / Li), let stand for 10 minutes, then discharge to 2V at a current density of 0.33C (vs. Li). + / Li), 5 cycles of charge and discharge, the resulting capacity is recorded as C2, the discharge specific capacity at 0.33C rate = C2 / mass of positive electrode active material;

[0223] The solid-state battery cells were then charged to 4.3V (vs. Li) at a current density of 0.33C. + / Li), let stand for 10 minutes, then discharge to 2V at a current density of 0.33C (vs. Li). + / Li), and after 190 charge-discharge cycles, the discharge capacity at this point is recorded as C3.

[0224] The capacity retention rate of a solid-state battery cell after 200 cycles at a current density of 0.33C is calculated as C3 / C1 × 100%.

[0225] Examples 2-12

[0226] The results are basically the same as in Example 1, except that the proportion of raw materials used in the synthesis of the solid electrolyte is different, resulting in a different composition of the halide oxide electrolyte, as shown in Table 1.

[0227] Examples 13-15

[0228] The process is basically the same as in Example 1, except that the ratio of positive active material and halide electrolyte is different in the preparation steps of the positive electrode layer material. The total mass content of positive active material and halide electrolyte in the positive electrode layer material is kept at 98%. Therefore, the mass content of halide electrolyte in the positive active layer is different, as shown in Table 1.

[0229] Example 16

[0230] The process is basically the same as in Example 1, except that the raw materials used in the synthesis of the solid electrolyte are different. Specifically, tantalum pentachloride and tantalum pentafluoride are replaced with niobium pentachloride and niobium pentafluoride, respectively. The specific synthesis steps are as follows:

[0231] The raw materials were weighed according to the molar ratio of lithium hydroxide: niobium pentachloride: zirconium tetrachloride: niobium pentafluoride of 1.1:0.9:0.1:0.02, mixed evenly in an inert atmosphere glove box, and then placed in an 80mL zirconium oxide ball mill jar. The mixture was milled at 500rpm for 16h. After the milling was completed, the powder was scraped off to obtain the electrolyte material. At the same time, the electrolyte material obtained by ball milling was sintered at 250℃ for 8h under an argon atmosphere to obtain the sintered halide electrolyte, the composition of which is shown in Table 1.

[0232] Comparative Example 1

[0233] This is essentially the same as Example 14, except that the raw materials for synthesizing the solid electrolyte are different; it does not contain zirconium tetrachloride and tantalum pentafluoride. The solid electrolyte synthesis steps are as follows:

[0234] The raw materials were weighed according to a 1:1 molar ratio of lithium hydroxide to tantalum pentachloride, mixed thoroughly in an inert atmosphere glove box, and then placed in an 80 mL zirconia ball mill jar. The mixture was milled at 500 rpm for 16 hours. After milling, the powder was scraped off to obtain the electrolyte material. Simultaneously, the ball-milled electrolyte material was sintered at 250 °C for 8 hours under an argon atmosphere to obtain a sintered halide oxide electrolyte, the composition of which is shown in Table 1. X-ray diffraction phase analysis of the obtained material showed it to be an amorphous material.

[0235] Comparative Example 2

[0236] This is essentially the same as Example 14, except that the raw materials for synthesizing the solid electrolyte are different; it does not contain zirconium tetrachloride. The synthesis steps for the solid electrolyte are as follows:

[0237] The raw materials were weighed according to a molar ratio of lithium hydroxide: tantalum pentachloride: tantalum pentafluoride of 1:1:0.02, mixed evenly in an inert atmosphere glove box, and then placed in an 80 mL zirconia ball mill jar. The mixture was milled at 500 rpm for 16 hours. After milling, the powder was scraped off to obtain the electrolyte material. Simultaneously, the ball-milled electrolyte material was sintered at 250 °C for 8 hours under an argon atmosphere to obtain a sintered halide oxide electrolyte, the composition of which is shown in Table 1. X-ray diffraction phase analysis of the obtained material showed it to be an amorphous material.

[0238] Comparative Example 3

[0239] This is essentially the same as Example 14, except that the raw materials for synthesizing the solid electrolyte are different; it does not contain tantalum pentafluoride. The solid electrolyte synthesis steps are as follows:

[0240] The raw materials were weighed according to a molar ratio of lithium hydroxide:tantalum pentachloride:zirconium tetrachloride of 1:0.8:0.2, mixed evenly in an inert atmosphere glove box, and then placed in an 80 mL zirconia ball mill jar. The mixture was milled at 500 rpm for 16 hours. After milling, the powder was scraped off to obtain the electrolyte material. Simultaneously, the ball-milled electrolyte material was sintered at 250 °C for 8 hours under an argon atmosphere to obtain a sintered halide oxide electrolyte, the composition of which is shown in Table 1. X-ray diffraction phase analysis of the obtained material showed it to be an amorphous material.

[0241] Comparative Example 4

[0242] This is essentially the same as Example 14, except that the raw materials for synthesizing the solid electrolyte are different; it does not contain tantalum pentafluoride. The solid electrolyte synthesis steps are as follows:

[0243] The raw materials were weighed according to the molar ratio of lithium oxide: tantalum pentachlorofluoride: zirconium tetrachloride of 1:0.1:1, mixed evenly in an inert atmosphere glove box, and then placed in an 80 mL zirconium oxide ball mill jar. The mixture was milled at 500 rpm for 16 h. After the milling was completed, the powder was scraped off to obtain the electrolyte material. At the same time, the electrolyte material obtained by ball milling was sintered at 250 °C for 8 h under an argon atmosphere to obtain the sintered halide electrolyte, the composition of which is shown in Table 1.

[0244] Table 1

[0245] The test results for each embodiment and comparative example are shown in Table 2.

[0246] Table 2

[0247] In Comparative Example 1, the halogen oxide electrolyte used was LiTaOCl4, which was free of zirconium and fluorine doping. Its ionic conductivity after 2 hours of exposure showed a significant decrease compared to its initial ionic conductivity, indicating poor water resistance and consequently, poor cycling performance. Comparative Example 2 used LiTaOF as the halogen oxide electrolyte. 0.1 Cl 3.9 Its zirconium-free form is doped only with fluorine, while Comparative Example 3 uses a Li-based halide electrolyte. 1.2 Ta 0.8 Zr 0.2 OCl4, which is undoped of fluorine but doped only with zirconium, exhibits decreased initial ionic conductivity and a still low decay rate, resulting in poor cycling performance. Comparative Example 4 uses Li₂Ta₄ as the halide electrolyte. 0.1 ZrOF 0.5 Cl4, with its high fluorine doping content, can lead to structural instability of the electrolyte material, making it prone to reacting with moisture in the air to generate corrosive HF acid, which damages the structural stability of the electrolyte itself. Secondly, excessive fluorine doping may hinder ion migration pathways, reducing ionic conductivity and consequently resulting in poor battery cycle performance.

[0248] The halide oxide electrolytes used in each embodiment have the structure of formula (1) and contain zirconium fluoride doping. By co-doping with fluorine ions and cations M', the ionic conductivity and water stability of the halide oxide electrolyte are improved, thereby improving the cycle performance stability of the solid-state battery, i.e., cycle life.

[0249] As can be seen from Examples 1 to 6, a fluorine ion doping amount y of 0.01 to 0.3 improves the cycle performance stability of solid-state batteries. Furthermore, a fluorine ion doping amount y of 0.05 to 0.15 can more effectively enhance the ion conductivity of the positive electrode layer and reduce the interfacial impedance of the halide oxide electrolyte, thereby improving the cycle performance of solid-state batteries while also achieving better discharge specific capacity.

[0250] As can be seen from Examples 1 and 7-12, a zirconium ion doping amount x of 0.1 to 0.9 improves the cycle performance stability of solid-state batteries. Furthermore, a zirconium ion doping amount x of 0.2 to 0.5, within which the zirconium ion doping ratio is within this range, is beneficial for the halide oxide electrolyte to have better structural stability. Therefore, the prepared halide oxide electrolyte has better ionic conductivity and water stability, and the corresponding solid-state battery can obtain better cycle performance and discharge specific capacity.

[0251] In Examples 1 and 13-15, the mass content of the halide oxide electrolyte is within this range, which effectively enhances the ion conductivity of the positive electrode layer and reduces interfacial impedance, thereby improving the cycle performance of the solid-state battery; while also maintaining a good discharge specific capacity. Furthermore, if the mass content of the halide oxide electrolyte is 15% to 30%, further controlling the mass content within this range can more effectively enhance the ion conductivity of the positive electrode layer and reduce interfacial impedance, thereby improving the cycle performance of the solid-state battery; while also maintaining a better discharge specific capacity.

[0252] As can be seen from Examples 1 and 16, the central metal element M is Ta. 5+ or Nb 5+ Both can improve the cycle performance of solid-state batteries.

[0253] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0254] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims, and the specification and drawings can be used to interpret the scope of the claims.

Claims

1. A solid-state battery, wherein, The positive electrode includes a positive electrode active layer comprising a positive electrode active material and a halide oxide electrolyte having a structure of formula (1): Li 1+x M 1-x+0.2y M' x O 1+x F y X 4-2x (1); Where M includes pentavalent metal ions of Group 5 transition metals, M' includes tetravalent metal ions of Group 4 transition metals, and X is Cl. - ,Br - and I - One or more of the following, 0.1≤x≤0.9, 0.01≤y≤0.

3.

2. The solid-state battery as described in claim 1, wherein, 0.2≤x≤0.5。 3. The solid-state battery according to any one of claims 1 to 2, wherein, 0.05≤y≤0.15。 4. The solid-state battery according to any one of claims 1 to 3, wherein, M includes Ta 5+ 、Nb 5+ and V 5+ One or more of them.

5. The solid-state battery according to any one of claims 1 to 4, wherein, M' includes Zr 4+ Hf 4+ and Ti 4+ One or more of them.

6. The solid-state battery according to any one of claims 1 to 5, wherein, The oxychloride electrolyte includes Li 1.1 Ta 0.91 Zr 0.1 O 1.1 F 0.05 Cl 3.8 、Li 1.1 Ta 0.92 Zr 0.1 O 1.1 F 0.1 Cl 3.8 、Li 1.1 Ta 0.93 Zr 0.1 O 1.1 F 0.15 Cl 3.8 、Li 1.1 Ta 0.94 Zr 0.1 O 1.1 F 0.2 Cl 3.8 、Li 1.1 Ta 0.96 Zr 0.1 O 1.1 F 0.3 Cl 3.8 、Li 1.2 Ta 0.82 Zr 0.2 O 1.2 F 0.1 Cl 3.6 、Li 1.3 Ta 0.72 Zr 0.3 O 1.3 F 0.1 Cl 3.4 、Li 1.4 Ta 0.62 Zr 0.4 O 1.4 F 0.1 Cl 3.2 、Li 1.6 Ta 0.42 Zr 0.6 O 1.6 F 0.1 Cl 2.8 、Li 1.8 Ta 0.22 Zr 0.8 O 1.8 F 0.1 Cl 2.4 、Li 1.9 Ta<0​​​​​​​​​ 1.1 Nb 0.92 Zr 0.1 O 1.1 F 0.1 Cl 3.8 One or more of them.

7. The solid-state battery according to any one of claims 1 to 6, wherein, One or more of the following conditions must be met: (1) The halide electrolytes include amorphous and crystalline states; (2) The particle size Dv50 of the halide oxide electrolyte is 1μm to 20μm; (3) The ionic conductivity of the halide electrolyte at 25°C is 1 mS / cm to 12 mS / cm.

8. The solid-state battery according to any one of claims 1 to 7, wherein, One or more of the following conditions must be met: (1) In the positive electrode active layer, the mass content of the positive electrode active material is 55% to 99%; (2) In the positive electrode active layer, the mass content of the halide electrolyte is 1% to 40%; (3) The particle size Dv50 of the positive electrode active material is 1nm to 50μm, and can be selected as 50nm to 15μm.

9. The solid-state battery as claimed in claim 8, wherein, One or more of the following conditions must be met: (1) In the positive electrode active layer, the mass content of the positive electrode active material is 70% to 85%; (2) In the positive electrode active layer, the mass content of the halide electrolyte is 15% to 30%.

10. The solid-state battery according to any one of claims 1 to 9, wherein, The positive electrode active layer also includes one or more of a conductive agent and a binder.

11. The solid-state battery of claim 10, wherein, One or more of the following conditions must be met: (1) The mass content of the conductive agent in the positive electrode active layer is 0.1% to 5%; (2) The mass content of the binder in the positive electrode active layer is 0.1% to 5%.

12. The solid-state battery as claimed in claim 10 or 11, wherein, One or more of the following conditions must be met: (1) The conductive agent includes one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphite, graphene and carbon nanofibers. (2) The adhesive includes one or more of the following: polyvinylidene fluoride, polytetrafluoroethylene, vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, hydrogenated nitrile rubber, styrene-butadiene rubber, polyacrylic acid, sodium polyacrylate, polyacrylamide, polyvinyl alcohol, sodium alginate, polymethacrylic acid, carboxymethyl chitosan and fluorinated acrylate resin.

13. The solid-state battery according to any one of claims 1 to 12, wherein, The thickness of the positive electrode active layer is 20 μm to 150 μm.

14. The solid-state battery according to any one of claims 1 to 13, wherein, The solid-state battery includes a solid electrolyte layer, which includes a solid electrolyte, and the solid electrolyte includes one or more of the following: sulfide solid electrolyte, halide solid electrolyte, oxide solid electrolyte, and polymer solid electrolyte. Optionally, the solid electrolyte includes a sulfide-based solid electrolyte.

15. The solid-state battery according to any one of claims 1 to 14, wherein, The solid-state battery is an all-solid-state battery.

16. A method for preparing a solid-state battery, wherein, The step of preparing the positive electrode active layer includes the following steps: The lithium source, M source, and M' source are mixed according to the stoichiometric ratio required for the halide oxide electrolyte and then sintered to obtain the halide oxide electrolyte; wherein, the lithium source includes one or more of lithium oxide, lithium carbonate, and lithium hydroxide, and the anions of both the M source and the M' source include fluoride ions and X ions; the halide oxide electrolyte has the structure of formula (1): Li 1+x M 1-x+0.2y M' x O 1+x F y X 4-2x (1); where M includes pentavalent metal ions of Group 5 subgroup metals, M' includes tetravalent metal ions of Group 4 subgroup metals, and X is Cl. - ,Br - and I - One or more of the following, 0.1≤x≤0.9, 0.01≤y≤0.3; The positive electrode active material and the halide electrolyte are mixed to prepare the positive electrode active layer.

17. A halide oxide electrolyte, wherein, The halide electrolyte has the structure of formula (1): Li 1+x M 1-x+0.2y M' x O 1+x F y X 4-2x (1); where M includes pentavalent metal ions of Group 5 subgroup metals, M' includes tetravalent metal ions of Group 4 subgroup metals, and X is Cl. - ,Br - and I - One or more of the following, 0.1≤x≤0.9, 0.01≤y≤0.

3.

18. The halide oxide electrolyte of claim 17, wherein, The halide oxide electrolyte is the halide oxide electrolyte in the solid-state battery as described in any one of claims 2 to 15.

19. An electrical appliance, wherein, It includes at least one of the solid-state battery according to any one of claims 1 to 15, the solid-state battery prepared by the preparation method according to claim 16, and the halide oxide electrolyte according to any one of claims 17 to 18.

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