Composite electrolyte membrane, method for preparing the same, battery cell, battery, and application thereof

Abstract

The application relates to the technical field of batteries, and discloses a composite electrolyte film, a preparation method of the composite electrolyte film, a battery monomer, a battery and application of the battery. The composite electrolyte film comprises a solid electrolyte film and a protective film, the protective film coats one side surface of the solid electrolyte film, the protective film comprises non-fiberized adhesive and a plurality of lithium metal stable particles, and each lithium metal stable particle is bonded by the non-fiberized adhesive. The composite electrolyte film of the application scheme is not prone to side reactions with a lithium metal negative electrode, can reduce the generation of lithium dendrites and is not prone to being pierced by lithium dendrites, has a small risk of short-circuit failure, and in addition, the composite electrolyte film has high mechanical properties such as tensile strength.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to a composite electrolyte membrane and its preparation method, a battery cell, a battery and its application. Background Technology

[0002] Solid-state batteries are batteries with a solid electrolyte, offering higher energy density and better safety compared to traditional liquid batteries. Solid-state batteries contain a solid electrolyte membrane, which is an indispensable part separating the positive and negative electrodes; its performance is one of the key factors affecting the overall performance of the solid-state battery.

[0003] Currently, sulfide solid electrolytes and halide solid electrolytes are widely used in solid-state batteries due to their high ionic conductivity at room temperature (e.g., ionic conductivity greater than 1 mS / cm).

[0004] However, when lithium metal is used as the negative electrode of a solid-state battery, sulfide solid electrolytes or halide solid electrolytes are prone to side reactions with the lithium metal negative electrode. At the same time, lithium metal negative electrodes are prone to the formation of lithium dendrites, which may puncture the solid electrolyte membrane, causing the solid-state battery to short-circuit and fail. This not only seriously affects the performance of solid-state batteries, but also hinders industrial production. Summary of the Invention

[0005] In view of the above problems, this application provides a composite electrolyte membrane and its preparation method, a battery cell, a battery and its application, aiming to solve the problems of traditional solid electrolyte membranes being prone to side reactions with lithium metal anodes and being easily pierced by lithium dendrites generated by lithium metal anodes.

[0006] In a first aspect, embodiments of this application provide a composite electrolyte membrane, including a solid electrolyte membrane and a protective membrane. The protective membrane covers one side surface of the solid electrolyte membrane and includes a non-fibrous binder and a plurality of lithium metal stabilizing particles, wherein each lithium metal stabilizing particle is bonded together by the non-fibrous binder.

[0007] The composite electrolyte membrane provided in this application embodiment coats at least one surface of a solid electrolyte membrane with a protective film. Multiple lithium metal stabilizing particles in the protective film are bonded together by a highly adhesive, non-fibrous binder. Thus, when the composite electrolyte membrane contacts a lithium metal anode, the protective film contacts the lithium metal anode, preventing the lithium metal stabilizing particles in the protective film from undergoing side reactions with the lithium metal anode. This also allows the Li... + The composite electrolyte membrane is uniformly dispersed on the surface of the negative electrode, which reduces the formation of lithium dendrites. At the same time, the mechanical properties such as tensile strength of the composite electrolyte membrane are enhanced, making it less likely to be punctured by lithium dendrites generated by the negative electrode. In addition, the composite electrolyte membrane can maintain good energy density and ionic conductivity, and has excellent performance.

[0008] In some embodiments, the lithium metal stabilizing particles include at least one of lithium fluoride, lithium nitride, lithium lanthanum zirconium tantalum oxide, and lithium lanthanum zirconium oxide.

[0009] By selecting these materials that are stable to lithium metal as protective film materials, no side reactions will occur with the lithium metal anode, and Li can also... + It is evenly dispersed on the surface of the negative electrode to reduce the formation of lithium dendrites.

[0010] In some embodiments, the ionic conductivity of the lithium metal stabilizing particles is 0.001 mS / cm to 10 mS / cm; and / or,

[0011] The electronic conductivity of the lithium metal stabilizing particles is less than 10. -6 mS / cm; and / or,

[0012] The particle size of the lithium metal stabilizing particles is less than 1 μm.

[0013] By selecting materials with high ionic conductivity and low electronic conductivity, and with very small particle size to form a protective film, the formation of lithium dendrites can be effectively reduced when in contact with the lithium metal anode, and the protective film can be made more dense, thus better preventing the solid electrolyte membrane from contacting the anode.

[0014] In some embodiments, the non-fibrous binder accounts for 0.01% to 49.9% of the total mass of the lithium metal stabilizing particles and the non-fibrous binder.

[0015] By including more lithium metal stabilizing particles in the protective film compared to the non-fibrous binder, it is possible to ensure that no side reactions occur with the lithium metal anode, and to make Li... + It is more evenly dispersed on the negative electrode, reducing the formation of lithium dendrites.

[0016] In some embodiments, the non-fibrous adhesive includes at least one selected from polyamide, polyethylene, polypropylene, polystyrene, polymethyl methacrylate, polyvinyl chloride, polycarbonate, polyurethane, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polyethylene oxide, nylon, polyethylene terephthalate, and polyoxymethylene.

[0017] By selecting a non-fibrous binder that melts when heated to a temperature above its melting point and then rapidly solidifies upon cooling, multiple lithium metal stable particles can be well bonded in the molten state, and the interfacial impedance caused by the change in negative electrode volume can be reduced when the composite electrolyte membrane is subsequently assembled into a solid-state battery.

[0018] In some embodiments, the solid electrolyte membrane comprises a plurality of solid electrolyte particles and a fibrous binder, the fibrous binder extending throughout the solid electrolyte membrane, and

[0019] The fibrous binder is wound around the surface of at least one of the solid electrolyte particles; and / or

[0020] The fibrous binder forms a network structure in the solid electrolyte membrane.

[0021] The network-like skeleton structure formed by the fiber filaments of the fibrous binder can effectively wrap around and support solid electrolyte particles, achieving effective bonding between multiple solid electrolyte particles, resulting in good performance and mechanical strength of the solid electrolyte membrane.

[0022] In some embodiments, the solid electrolyte particles include at least one of sulfide solid electrolyte particles and halide solid electrolyte particles; and / or,

[0023] The solid electrolyte particles have a particle size of 0.1 μm to 100 μm; and / or,

[0024] The fibrous binder includes polytetrafluoroethylene.

[0025] Composite electrolyte membranes can exhibit better electrochemical performance and higher ionic conductivity at room temperature by using sulfide solid electrolyte particles and / or halide solid electrolyte particles with smaller particle sizes.

[0026] In some embodiments, the thickness of the protective film is less than or equal to 5 μm.

[0027] By making the protective film very thin, its coating on the surface of the solid electrolyte membrane will not affect the ion-conducting properties of the solid electrolyte membrane.

[0028] In some embodiments, the ionic conductivity of the composite electrolyte membrane is 0.1 mS / cm to 100 mS / cm; and / or,

[0029] The thickness of the composite electrolyte membrane is less than or equal to 200 μm; and / or,

[0030] The tensile strength of the composite electrolyte membrane is 0.1 MPa to 5 MPa.

[0031] Therefore, the composite electrolyte membrane has high ionic conductivity, thin thickness, and high tensile strength, resulting in good performance.

[0032] Secondly, embodiments of this application provide a method for preparing a composite electrolyte membrane, comprising the following steps:

[0033] Formation of a solid electrolyte membrane;

[0034] The composite electrolyte membrane is formed by mixing a non-fibrous binder and multiple lithium metal stabilizing particles and coating one side surface of the solid electrolyte membrane.

[0035] The method for preparing the composite electrolyte membrane provided in this application involves forming a protective film on one side surface of a solid electrolyte membrane. Multiple lithium metal stabilizing particles in the protective film are well bonded together by a non-fibrous binder. This isolates the solid electrolyte membrane from the lithium metal anode, preventing direct contact and reducing side reactions. Furthermore, the non-fibrous binder's good adhesion improves the tensile strength and other mechanical properties of the composite electrolyte membrane, making it less susceptible to puncture by lithium dendrites generated at the anode. It also reduces interfacial impedance caused by volume changes at the anode. Moreover, the lithium metal stabilizing particles are unlikely to chemically react with the lithium metal anode, and the Li... + Uniform dispersion on the negative electrode surface can reduce the formation of lithium dendrites. In addition, this dry preparation method does not introduce organic solvents, avoiding the negative impact of organic solvents on the composite electrolyte membrane, which is conducive to the continuous production and large-scale rapid mass production of composite electrolyte membranes.

[0036] In some embodiments, mixing the non-fibrous binder and a plurality of lithium metal stabilizing particles and coating one side surface of the solid electrolyte membrane includes:

[0037] The non-fibrous binder and the plurality of lithium metal stabilizing particles are mixed to form a mixed powder;

[0038] The mixed powder is sprayed onto the surface of the solid electrolyte membrane, calendered at a temperature higher than the melting point of the non-fibrous binder, and then cooled.

[0039] A protective film is formed on the surface of the solid electrolyte membrane through a spraying process, allowing for a very thin film thickness. This ensures the composite electrolyte membrane has high ionic conductivity. Simultaneously, the mixture is calendered at a temperature higher than the melting point of the non-fibrous binder. The non-fibrous binder is in a molten state, which effectively bonds the lithium metal stabilizing particles, improving the mechanical properties of the protective film. Without chemically reacting with the lithium metal anode, this allows the Li... + The electrolyte is more evenly dispersed on the negative electrode, reducing the formation of lithium dendrites and decreasing the risk of being punctured by them. This preparation method is simple and easy to implement, without the addition of any organic solvents, thus avoiding the negative impact of organic solvents on the electrolyte particles. This facilitates the continuous production and large-scale rapid mass production of composite electrolyte membranes.

[0040] In some embodiments, the spraying is electrostatic spraying, wherein the nitrogen pressure for electrostatic spraying is 0.1 MPa to 2 MPa; and / or,

[0041] The nozzle diameter for electrostatic spraying is 1mm to 1.5mm; and / or,

[0042] The voltage for electrostatic spraying is 80KV to 100KV.

[0043] Electrostatic spraying is simple to implement and can produce very thin protective films, which is beneficial for industrial production.

[0044] In some embodiments, mixing the non-fibrous binder and a plurality of lithium metal stabilizing particles and coating one side surface of the solid electrolyte membrane includes:

[0045] The non-fibrous binder and the plurality of lithium metal stabilizing particles are mixed to form a mixed powder;

[0046] The mixed powder is calendered at a temperature higher than the melting point of the non-fibrous binder, and then cooled to form a protective film.

[0047] The protective film is bonded to one side surface of the solid electrolyte membrane to form the composite electrolyte membrane.

[0048] By moltenening the non-fibrous binder at a temperature above its melting point, the molten non-fibrous binder bonds itself to partial surfaces of multiple lithium metal stabilizing particles. After cooling, the non-fibrous binder rapidly solidifies, achieving effective bonding to even more surfaces of the lithium metal stabilizing particles. Finally, this protective film is adhered to the surface of the solid electrolyte membrane using an adhesive, thereby enhancing the mechanical properties of the composite electrolyte membrane and enabling Li... + More uniform dispersion on the negative electrode reduces lithium dendrite formation, decreases the risk of being punctured by lithium dendrites, improves the overall performance of the composite electrolyte membrane, and facilitates continuous production and large-scale rapid mass production of the composite electrolyte membrane.

[0049] Thirdly, embodiments of this application provide a battery cell comprising a positive electrode, a negative electrode, and the aforementioned composite electrolyte membrane or a composite electrolyte membrane prepared by the aforementioned method, wherein the protective membrane is located between the composite electrolyte membrane and the negative electrode.

[0050] The battery cells provided in this application embodiment have a low risk of short-circuit failure, high safety, and good performance.

[0051] Fourthly, embodiments of this application provide a battery including the aforementioned battery cell.

[0052] The battery provided in this application embodiment has a low short-circuit rate, high cycle stability, high safety, and good performance.

[0053] Fifthly, embodiments of this application provide an electrical device including the battery described above.

[0054] The electrical device provided in this application embodiment has high cycle stability, high safety, and good performance.

[0055] Sixthly, embodiments of this application provide an energy storage device, including the battery described above.

[0056] The energy storage device provided in this application embodiment has high cycle stability, high safety, and good performance.

[0057] The above description is merely an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, specific embodiments of this application are given below. Attached Figure Description

[0058] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the alternative embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0059] Figure 1 This is a schematic diagram of the structure of the composite electrolyte membrane in some embodiments of this application;

[0060] Figure 2 This is a schematic diagram of the structure of the protective film in some embodiments of this application;

[0061] Figure 3 This is a schematic diagram of the structure of a solid electrolyte membrane according to some embodiments of this application;

[0062] Figure 4 This is a process flow diagram of the preparation of composite electrolyte membranes according to some embodiments of this application;

[0063] Figure 5 This is a process flow diagram of the preparation of solid electrolyte membranes according to some embodiments of this application;

[0064] Figure 6 This is a process flow diagram of the preparation of composite electrolyte membranes according to some embodiments of this application;

[0065] Figure 7 This is a process flow diagram of the preparation of composite electrolyte membranes according to some embodiments of this application;

[0066] Figure 8 This is a schematic diagram of a square-structured battery cell according to some embodiments of this application;

[0067] Figure 9 This is a schematic diagram of the exploded structure of a battery cell according to some embodiments of this application;

[0068] Figure 10 This is a schematic diagram of the structure of the positive electrode, negative electrode, and composite electrolyte membrane in some embodiments of this application;

[0069] Figure 11 This is a schematic diagram of the exploded structure of a battery according to some embodiments of this application;

[0070] Figure 12 This is a schematic diagram of the structure of a vehicle according to some embodiments of this application.

[0071] The reference numerals in the detailed embodiments are as follows:

[0072] 1. Composite electrolyte membrane; 11. Solid electrolyte membrane; 12. Protective membrane; 102. Positive electrode; 103. Negative electrode;

[0073] 21. Shell; 22. Cover plate;

[0074] 30. Battery cell;

[0075] 40. Battery; 401. Box body; 4011. Box body; 4012. Box cover;

[0076] 50. Vehicle; 501. Controller; 502. Motor. Detailed Implementation

[0077] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0078] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0079] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0080] 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 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 mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0081] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0082] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0083] In the description of the embodiments of this application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0084] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0085] Against the backdrop of energy conservation and emission reduction, new energy technologies are developing rapidly, with breakthroughs and applications in battery technology being one example. As battery applications become increasingly widespread, especially with the rapid development of electric vehicles in recent years, power batteries have experienced rapid growth and a surge in demand. Consequently, battery safety has become a growing concern.

[0086] Solid-state batteries are a type of battery that uses solid electrodes (positive and negative electrodes) and a solid electrolyte. Compared to traditional liquid batteries, solid-state batteries have higher energy density and better safety, and are considered one of the important future directions for battery development. Solid-state batteries contain a solid electrolyte membrane, which is an indispensable part that separates the positive and negative electrodes, and its performance is one of the key factors affecting the overall performance of solid-state batteries.

[0087] Solid electrolyte membranes contain components such as solid electrolyte particles and binders. Currently, commonly used solid electrolyte particles are sulfide electrolyte particles, halide electrolyte particles, and polymer electrolyte particles. Among them, the ionic conductivity of polymer electrolyte particles is usually less than 1 mS / cm at room temperature (usually around 25°C), while sulfide electrolyte particles and halide electrolyte particles have high ionic conductivity at room temperature, for example, greater than 1 mS / cm. Therefore, sulfide electrolyte particles and halide electrolyte particles are widely used in solid-state batteries.

[0088] However, in practical applications, sulfide electrolyte particles or halide electrolyte particles are prone to side reactions with lithium metal anodes. Furthermore, when lithium metal is used as the anode, lithium metal anodes are prone to forming lithium dendrites, which can easily pierce the solid electrolyte membrane and cause short circuit failure of the solid battery. Thus, it not only hinders the simultaneous use of lithium metal anodes, sulfide electrolyte particles or halide electrolyte particles, but also seriously affects the performance of solid batteries.

[0089] Currently, the conventional solution to the aforementioned problems of solid-state batteries that use sulfide or halide electrolyte particles to form solid electrolyte membranes and lithium metal as the negative electrode is to form a polymer electrolyte membrane on the surface of the solid electrolyte membrane through a wet coating process. Since the polymer electrolyte itself is stable to the negative electrode and does not easily react, the polymer electrolyte membrane can serve as a buffer layer between the solid electrolyte membrane and the lithium metal negative electrode, separating the solid electrolyte membrane from the lithium metal negative electrode. This can reduce side reactions between the solid electrolyte membrane and the lithium metal negative electrode and alleviate the problem of lithium dendrites piercing the solid electrolyte membrane.

[0090] However, wet coating processes require the introduction of organic solvents, and sulfide or halide electrolyte particles are prone to side reactions with organic solvents, affecting the performance of the electrolyte particles. At the same time, the polymer electrolyte film formed by wet coating processes is generally thick, for example, its thickness may be greater than or equal to 10 μm, which affects the energy density of solid-state batteries. Moreover, the ionic conductivity of polymer electrolyte films at room temperature is low, resulting in a decrease in the overall ionic conductivity of solid-state electrolyte films, which affects the electrochemical performance of solid-state batteries. In addition, polymer electrolyte films have poor mechanical properties and cannot solve the problem of lithium dendrites piercing solid-state electrolyte films.

[0091] Current research on the solid electrolyte interface (SEI) film in liquid lithium-ion batteries has revealed that SEI can significantly improve the cycle stability of liquid lithium-ion batteries and alleviate the lithium dendrite puncture problem. One of the main components of SEI is lithium fluoride (LiF). Therefore, we attempted to fabricate a LiF-containing protective film using a dry process and place this LiF-containing protective film between the solid electrolyte film and the lithium metal anode. The LiF-containing protective film prevents direct contact between the solid electrolyte film and the lithium metal anode and mitigates the lithium dendrite puncture problem in the solid electrolyte film, thereby improving the cycle stability of the solid-state battery. Based on this research, the following scheme is proposed in this application.

[0092] Composite electrolyte membrane

[0093] Firstly, embodiments of this application provide a composite electrolyte membrane. In some embodiments, the composite electrolyte membrane of this application can be as follows: Figure 1 and Figure 2 As shown, the composite electrolyte membrane 1 includes a solid electrolyte membrane 11 and a protective membrane 12. The protective membrane 12 covers one side surface of the solid electrolyte membrane 11. The protective membrane 12 includes at least a non-fibrous binder and a plurality of lithium metal stabilizing particles, and each lithium metal stabilizing particle is bonded together by the non-fibrous binder.

[0094] It should be understood that when the protective film 12 covers one side of the solid electrolyte membrane 11, it means that the protective film 12 only covers one surface of the solid electrolyte membrane 11, and this surface faces the negative electrode when assembled into a solid-state battery, thus allowing the protective film to directly contact the negative electrode. It should be noted that the protective film 12 is not completely dense, therefore some portion of the solid electrolyte membrane 11 will be exposed, allowing the composite electrolyte membrane to react with Li. + To achieve effective transmission.

[0095] It should be understood that the protective film 12 includes at least a non-fibrous binder and multiple lithium metal stabilizing particles, meaning that the protective film 12 may include only a non-fibrous binder and multiple lithium metal stabilizing particles, or the protective film 12 may include other components in addition to a non-fibrous binder and multiple lithium metal stabilizing particles, without specific limitations here.

[0096] The aforementioned lithium metal stabilizing particles refer to substances that are stable to Li metal and do not chemically react with Li metal, such as lithium fluoride (LiF), lithium nitride (Li3N), lithium lanthanum zirconium tantalum oxide (LLZTO), and lithium lanthanum zirconium oxide (LLZO). The ionic conductivity of these lithium metal stabilizing particles is 0.001 mS / cm to 10 mS / cm, optionally 0.01 mS / cm to 10 mS / cm. For example, the ionic conductivity of the lithium metal stabilizing particles can be 0.01 mS / cm, 0.1 mS / cm, 1 mS / cm, 3 mS / cm, 7 mS / cm, or 10 mS / cm. The electronic conductivity of the lithium metal stabilizing particles is less than 10. -6 mS / cm, optionally less than 10 -7 mS / cm, for example, the electronic conductivity of lithium metal stabilized particles can be 10. -8 mS / cm, 10 -9 mS / cm or 10 -10 The lithium metal stabilizing particles have high ionic conductivity and low electronic conductivity. When in contact with the negative electrode, they can effectively suppress the formation of lithium dendrites and will not undergo side reactions with the lithium metal negative electrode, thus providing good protection.

[0097] The aforementioned non-fibrous binder can bond to a portion of the surface of most lithium metal stabilizing particles in all lithium metal stabilizing particles, thereby achieving effective bonding of all lithium metal stabilizing particles. The non-fibrous binder may include one or more combinations of polyamide (PA), polycarbonate (PC), polyethylene (PE), polypropylene (PP), polystyrene (PS), polymethyl methacrylate (PMMA), polyvinyl chloride (PVC), polyurethane (PU), polyvinylidene fluoride (PVDF), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), polyethylene oxide (PEOX), nylon, polyethylene terephthalate (PET), and polyformaldehyde (POM). Non-fibrous binders can tightly bond lithium metal stable particles, thereby enhancing the mechanical properties of the composite electrolyte membrane, such as tensile strength, and can effectively reduce the interfacial impedance generated by volume changes in the negative electrode during charging and discharging.

[0098] The composite electrolyte membrane provided in this application embodiment, by coating one side surface of the solid electrolyte membrane with a protective film, wherein multiple lithium metal stabilizing particles in the protective film are bonded together by a highly adhesive, non-fibrous binder, ensures that when the composite electrolyte membrane comes into contact with the lithium metal anode, the protective film contacts the lithium metal anode, preventing the lithium metal stabilizing particles in the protective film from undergoing side reactions with the lithium metal anode, and also allowing Li... + The composite electrolyte membrane is uniformly dispersed on the surface of the negative electrode, which reduces the formation of lithium dendrites. At the same time, the mechanical properties such as tensile strength of the composite electrolyte membrane are enhanced, making it less likely to be punctured by lithium dendrites generated by the negative electrode. In addition, the composite electrolyte membrane can maintain good energy density and ionic conductivity, and has excellent performance.

[0099] In some embodiments, the particle size of the lithium metal stabilizing particles is less than 1 μm, optionally less than or equal to 0.5 μm. For example, the particle size of the lithium metal stabilizing particles can be 0.001 μm, 0.01 μm, 0.1 μm, or 0.5 μm, etc. The particle size of the lithium metal stabilizing particles is in the nanometer range. The smaller the particle size, the higher the density of the protective film and the better the protective effect on the solid electrolyte membrane.

[0100] In some embodiments, the non-fibrous binder accounts for 0.01% to 49.9% of the total mass of the lithium metal stabilizing particles and the non-fibrous binder, optionally 1% to 20%. For example, the non-fibrous binder may account for 1%, 5%, 10%, 15%, or 20% of the total mass of the lithium metal stabilizing particles and the non-fibrous binder. By making the lithium metal stabilizing particles slightly more abundant than the non-fibrous binder, it is ensured that no side reactions occur with the lithium metal anode, i.e., better stability of the lithium metal anode, thereby improving the cycle stability of the battery using this composite electrolyte membrane.

[0101] In some embodiments, the thickness of the protective film is less than or equal to 5 μm, and optionally less than or equal to 3 μm. For example, the thickness of the protective film may be 0.1 μm, 0.5 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, or 3 μm, etc.

[0102] Therefore, the protective film in this embodiment is very thin, so the introduction of the protective film has little impact on the ionic conductivity of the composite electrolyte membrane, thus ensuring the ionic conductivity of the composite electrolyte membrane.

[0103] In some embodiments, such as Figure 3 As shown, the solid electrolyte membrane 11 includes a plurality of solid electrolyte particles and a fibrous binder, the fibrous binder extending through the solid electrolyte membrane 11 and wrapped around the surface of at least one solid electrolyte particle, and / or the fibrous binder forming a network structure in the solid electrolyte membrane 11.

[0104] It should be understood that solid electrolyte particles can give composite electrolyte membranes high ionic conductivity and enable them to effectively carry lithium ions (Li₂O₃). + Transmission. The solid electrolyte particles can specifically be solid electrolyte powder particles, and the particle size of the solid electrolyte powder particles can be 0.1μm to 100μm, optionally 0.5μm to 20μm. For example, the particle size of the solid electrolyte powder particles can be 0.5μm, 1μm, 5μm, 10μm, 15μm or 20μm, etc.

[0105] As an example, solid electrolyte particles may include sulfide solid electrolyte particles and / or halide solid electrolyte particles.

[0106] The sulfide solid electrolyte particles may include Li 5.4 PS 4.5 Cl 1.5 Li3PS4(LPS), Li 10 GeP2S 12 One or more combinations of Li6PS5Cl (LPSCl), Li6PS5I (LPSI), and Li6PS5Br (LPSBr) are used. Using sulfide solid electrolyte particles as the electrolyte can improve the electrochemical stability of solid electrolyte membranes, thereby enhancing the electrochemical stability of composite electrolyte membranes.

[0107] Halogenated solid electrolyte particles may include Li3InCl6, Li3YCl6, Li3ScCl6, Li3TaCl6, Li3ZrCl6, and Li3Y 1-x In x Combinations of one or more of Cl6 (0≤x≤1), Li3YbCl6, and Li3HoCl6. Using halide solid electrolyte particles as the electrolyte enables solid electrolyte membranes to possess strong resistance to oxidation and etching and higher electrochemical stability, thereby enabling composite electrolyte membranes to possess strong resistance to oxidation and etching and higher electrochemical stability.

[0108] In applications, the aforementioned fibrous binder can be a fibrous thermoplastic polymer binder, and the network structure of the fibrous thermoplastic polymer binder can be used to wrap around and support multiple solid electrolyte particles.

[0109] The fibrous thermoplastic polymer binder can be polytetrafluoroethylene (PTFE), etc. The network-like skeleton structure formed by PTFE fibers can effectively wrap around and support multiple solid electrolyte particles, achieving bonding between them. Simultaneously, it exposes a portion of the solid electrolyte particles' surface—the surface not wrapped by PTFE—allowing for the Li-ion bonding process to occur through the solid electrolyte particles. + Transmission function.

[0110] This results in composite electrolyte membranes having high ionic conductivity, being easy to process, and being able to be processed into thin composite electrolyte membranes.

[0111] In some embodiments, the fibrous binder comprises any proportion of the total mass of the solid electrolyte particles and the fibrous binder.

[0112] Further, the fibrous binder accounts for 0.01% to 49.9% of the total mass of the solid electrolyte particles and the fibrous binder, optionally 1% to 20%. For example, the fibrous binder can account for 1%, 5%, 10%, 15%, or 20% of the total mass of the solid electrolyte particles and the fibrous binder. By setting the solid electrolyte membrane to have more solid electrolyte particles than fibrous binder, effective bonding of multiple solid electrolyte particles can be achieved, improving the mechanical properties of the solid electrolyte membrane, and also enabling better Li... + transmission.

[0113] In some embodiments, the thickness of the composite electrolyte membrane is less than or equal to 200 μm, optionally between 20 and 200 μm. For example, the thickness of the composite electrolyte membrane can be 20 μm, 50 μm, 80 μm, 100 μm, 130 μm, 160 μm, or 200 μm, etc. Therefore, the composite electrolyte membrane is relatively thin, enabling the solid-state battery using this composite electrolyte membrane to achieve high energy density and good performance.

[0114] In some embodiments, because the protective film is not a completely dense film, a thinner protective film will not affect the solid electrolyte membrane's Li₂ process. + For transport, the ionic conductivity of the composite electrolyte membrane is 0.1 mS / cm to 100 mS / cm, optionally 0.5 mS / cm to 10 mS / cm. For example, the ionic conductivity of the composite electrolyte membrane can be 0.5 mS / cm, 1 mS / cm, 3 mS / cm, 5 mS / cm, 7 mS / cm, or 10 mS / cm, etc. Therefore, the ionic conductivity of the composite electrolyte membrane is still relatively high, especially for Li... + Its transmission performance is relatively good.

[0115] In some embodiments, the tensile strength of the composite electrolyte membrane is 0.1 MPa to 5 MPa, optionally 0.3 MPa to 3 MPa. For example, the tensile strength of the composite electrolyte membrane can be 0.3 MPa, 0.5 MPa, 1 MPa, 2 MPa, or 3 MPa, etc. Therefore, the composite electrolyte membrane has high tensile strength and good mechanical properties, effectively mitigating the lithium dendrite puncture problem.

[0116] Preparation method of composite electrolyte membrane

[0117] Secondly, embodiments of this application provide a method for preparing a composite electrolyte membrane, wherein the composite electrolyte membrane includes a non-fibrous binder and multiple lithium metal stabilizing particles.

[0118] The preparation process of the composite electrolyte membrane in this application embodiment is as follows: Figure 4 As shown, it may include the following steps:

[0119] S10. Formation of a solid electrolyte membrane;

[0120] S20. A non-fibrous binder and a plurality of lithium metal stabilizing particles are mixed and coated onto at least one surface of a solid electrolyte membrane to form a composite electrolyte membrane.

[0121] In the preparation method of the composite electrolyte membrane in the embodiments of this application, the composite electrolyte membrane is the composite electrolyte membrane 1 of the embodiments of the above application.

[0122] The method for preparing the composite electrolyte membrane provided in this application involves forming a protective film on the surface of a solid electrolyte membrane. Multiple lithium metal stabilizing particles in the protective film are well bonded together by a non-fibrous binder. This isolates the solid electrolyte membrane from the lithium metal anode, preventing direct contact and reducing side reactions between them. Furthermore, the non-fibrous binder has good adhesion, improving the tensile strength and other mechanical properties of the composite electrolyte membrane, making it less susceptible to puncture by lithium dendrites generated at the anode. It also reduces interfacial impedance caused by volume changes at the anode. Moreover, the lithium metal stabilizing particles are unlikely to chemically react with the lithium metal anode, and the Li... + Uniform dispersion on the negative electrode surface can reduce the formation of lithium dendrites. In addition, this dry preparation method does not introduce organic solvents, avoiding the negative impact of organic solvents on the composite electrolyte membrane, which is conducive to the continuous production and large-scale rapid mass production of composite electrolyte membranes.

[0123] [Step S10]

[0124] The preparation process of step S10 is as follows: Figure 5 As shown, it may include the following steps:

[0125] S101. The fibrous binder and multiple solid electrolyte particles are mixed to form a mixture;

[0126] S102. The mixture is subjected to fiberization treatment to form a fiberized mixture;

[0127] S103. The fibrous mixture is subjected to at least one first calendering process to form a solid electrolyte membrane.

[0128] It should be noted that the solid electrolyte particles and fibrous binder in step S10 can be referred to the above embodiments, and will not be repeated here.

[0129] The solid electrolyte membrane preparation method provided in this application firstly involves fiberizing the fiber binder into fibrous filaments. These filaments are wound around the surface of at least one solid electrolyte particle and penetrate the solid electrolyte membrane, thus bonding multiple solid electrolyte particles together. Then, a first calendering process is performed to thin the solid electrolyte membrane. The portion of the surface of the multiple solid electrolyte particles not covered with the fiber binder ensures good ionic conductivity of the solid electrolyte membrane. At the same time, the thinner solid electrolyte membrane improves the overall performance of the solid electrolyte membrane, which is beneficial for achieving continuous production and large-scale rapid mass production of solid electrolyte membranes.

[0130] In step S101, the fibrous binder accounts for 0.01% to 49.9% of the total mass of the fibrous binder and solid electrolyte particles, optionally 1% to 20%. For example, the fibrous binder may account for 1%, 5%, 10%, 15%, or 20% of the total mass of the fibrous binder and solid electrolyte particles. As an example, the ratio of solid electrolyte particles to fibrous binder is 99:1. By setting the solid electrolyte membrane to contain more solid electrolyte particles than fibrous binder, effective bonding between multiple solid electrolyte particles can be achieved, improving the mechanical properties of the solid electrolyte membrane, while ensuring minimal impact on the ionic conductivity of the solid electrolyte membrane.

[0131] In step S102, a fiberizing device can be used to fiberize the mixture, processing the fiber binder into fiber filaments. The network structure constructed by the fiber filaments can be used to wrap and support solid electrolyte powder particles to bond multiple solid electrolyte particles. The fiberizing device may include a high-intensity mixer, a high-speed shearing machine, and a high-speed ball mill, etc.

[0132] Taking a high-intensity mixer as an example of a fiberizing device, the speed of the high-intensity mixer can be greater than or equal to 500 rpm, optionally greater than or equal to 3000 rpm. For example, the speed of the high-intensity mixer can be 3000 rpm, 4000 rpm, 5000 rpm, 6000 rpm, 7000 rpm, or 8000 rpm, etc. This speed can effectively fiberize the fiberized binder.

[0133] The mixing time of the high-intensity mixer can be from 6 min to 600 min, optionally from 6 min to 200 min. For example, the mixing time of the high-intensity mixer can be 6 min, 10 min, 50 min, 100 min, 150 min, or 200 min, etc. At this time, the fibrous binder has sufficient time to achieve the fibrous treatment.

[0134] In step S103, the first calendering process can be performed once or multiple times, depending on the actual application. The first calendering process can include any one of hot rolling, flatbed hot pressing, etc.

[0135] Taking hot rolling as an example of the first calendering process, a roller press can be used to hot roll the fibrous mixture. The temperature of the hot rolling process can be 25℃ to 150℃, optionally 50℃ to 150℃. For example, the temperature of the hot rolling process can be 50℃, 70℃, 90℃, 100℃, 120℃, or 150℃, etc. The rotation speed of the hot rolling process can be 1rpm to 50rpm, optionally 1rpm to 20rpm. For example, the rotation speed of the hot rolling process can be 1rpm, 5rpm, etc. The rolling pressure of the hot rolling mill can be 10 rpm, 15 rpm, or 20 rpm, etc.; the horizontal rolling pressure of the hot rolling mill can be 1t to 80t, optionally 10t to 80t. For example, the horizontal rolling pressure of the hot rolling mill can be 10t, 30t, 50t, 70t, or 80t, etc.; the vertical rolling pressure of the hot rolling mill can be 1t to 80t, optionally 10t to 80t. For example, the vertical rolling pressure of the hot rolling mill can be 10t, 30t, 50t, 70t, or 80t, etc. This allows for the formation of a thinner solid electrolyte membrane, and also results in a thinner composite electrolyte membrane subsequently formed.

[0136] After the first calendering process, the thickness of the solid electrolyte membrane can be less than or equal to 200 μm, optionally less than or equal to 100 μm. For example, the thickness of the solid electrolyte membrane can be 10 μm, 20 μm, 40 μm, 60 μm, 80 μm, or 100 μm, etc. A thin solid electrolyte membrane allows for higher energy density and better performance in solid-state batteries using this membrane.

[0137] [Step S20]

[0138] As an example, the preparation process of step S20 is as follows: Figure 6 As shown, it may include the following steps:

[0139] S201. Mix a non-fibrous binder with multiple lithium metal stabilizing particles to form a mixed powder;

[0140] S202. The mixed powder is sprayed onto one side surface of a solid electrolyte membrane using a spraying process to form a mixture;

[0141] S203. The mixture is subjected to at least one second calendering treatment at a temperature higher than the melting point of the non-fibrous binder, followed by a cooling treatment to form a composite electrolyte membrane.

[0142] It should be noted that the solid electrolyte membrane, non-fibrous binder, and lithium metal stabilizing particles in step S20 can be referred to the above embodiments, and will not be repeated here.

[0143] The method for preparing the composite electrolyte membrane provided in this application involves forming a protective film on the surface of a solid electrolyte membrane through a spraying process. This allows for a very thin protective film, minimizing its impact on the ionic conductivity of the solid electrolyte membrane and ensuring high ionic conductivity of the composite electrolyte membrane. Simultaneously, the mixture is calendered at a temperature higher than the melting point of the non-fibrous binder. The non-fibrous binder is in a molten state, which effectively bonds the lithium metal stabilizing particles, improving the mechanical properties of the protective film. Furthermore, without chemically reacting with the lithium metal anode, the protective film, upon contact with the lithium metal anode, allows the Li... + Uniform deposition on the negative electrode reduces lithium dendrite formation and the risk of being pierced by lithium dendrites, without affecting the Li... + The preparation method is simple and easy to implement, without the addition of organic solvents, thus avoiding the negative impact of organic solvents on electrolyte particles and facilitating the continuous production and large-scale rapid mass production of composite electrolyte membranes.

[0144] In step S201, the non-fibrous binder and multiple lithium metal stabilizing particles can be added to a container and stirred thoroughly to obtain a mixed powder.

[0145] The non-fibrous binder accounts for 0.01% to 49.9% of the total mass of the non-fibrous binder and lithium metal stabilizer particles. As an example, the ratio of lithium metal stabilizer particles to non-fibrous binder is 99:1.

[0146] In step S202, the spraying process can be electrostatic spraying, etc. Electrostatic spraying can reduce the protective film thickness to less than 5μm, and no organic solvents are added throughout the process.

[0147] In the electrostatic spraying process, the nitrogen (N2) pressure is 0.1 MPa to 2 MPa, optionally 1 MPa to 2 MPa. For example, the N2 pressure in the electrostatic spraying process can be 1 MPa, 1.2 MPa, 1.4 MPa, 1.6 MPa, 1.8 MPa, or 2 MPa, etc. Electrostatic spraying at this pressure yields better results.

[0148] The nozzle diameter in the electrostatic spraying process is 1mm to 1.5mm, optionally 1.2mm to 1.5mm. For example, the nozzle diameter in the electrostatic spraying process can be 1.2mm, 1.3mm, 1.4mm, or 1.5mm, etc. This results in a better electrostatic spraying effect.

[0149] The operating voltage in the electrostatic spraying process is 80KV to 100KV, optionally 90KV to 100KV. For example, the operating voltage in the electrostatic spraying process can be 90KV, 92KV, 94KV, 96KV, 98KV, or 100KV, etc. This results in better electrostatic spraying effects.

[0150] In step S203, the second calendering process can be performed once or multiple times, depending on the actual application. This second calendering process can include any one of flatbed hot pressing, hot rolling, etc.

[0151] There are many types of non-fibrous adhesives, each with its own melting point. Therefore, simply selecting a temperature higher than the melting point of the non-fibrous adhesive will allow it to melt. For example, PC has a melting point of approximately 155°C, and PA has a melting point of approximately 250°C. If only PC is selected as the non-fibrous adhesive, the second calendering temperature can be set higher than 155°C, for example, 200°C. If both PC and PA are selected as the non-fibrous adhesive, the second calendering temperature can be set higher than 250°C, for example, 260°C. No specific limitation is made here.

[0152] As an example, the second calendering temperature can be from 0.1°C to 400°C, thereby allowing each non-fibrous binder to be in a molten state at a temperature above its melting point.

[0153] Taking the second calendering process as flat plate hot pressing as an example, the pressure of flat plate hot pressing can be 0.1 MPa to 80 MPa, optionally 10 MPa to 80 MPa. For example, the pressure of flat plate hot pressing can be 10 MPa, 20 MPa, 30 MPa, 40 MPa, 50 MPa, or 80 MPa, etc. The composite electrolyte membrane prepared under this pressure has good surface flatness. It should be noted that good surface flatness of the protective film means that the thickness deviation of different areas of the protective film is less than or equal to 3 μm.

[0154] The cooling process in step S203 can be performed at room temperature, for example, around 25°C.

[0155] As another example, the preparation process of step S20 is as follows: Figure 7 As shown, it may include the following steps:

[0156] S204. A non-fibrous binder and multiple lithium metal stabilizing particles are mixed to form a mixed powder;

[0157] S205. The mixed powder is subjected to at least one second calendering treatment at a temperature higher than the melting point of the non-fibrous binder, followed by a cooling treatment to form a protective film;

[0158] S206. A protective film is bonded to one side surface of a solid electrolyte membrane using an adhesive to form a composite electrolyte membrane.

[0159] The method for preparing the composite electrolyte membrane provided in this application involves molten non-fibrous binder at a temperature above its melting point. The molten non-fibrous binder bonds itself to a portion of the surface of multiple lithium metal stabilizing particles. After cooling, the non-fibrous binder rapidly solidifies, achieving effective bonding to more surfaces of the lithium metal stabilizing particles. Finally, the protective film is adhered to the surface of the solid electrolyte membrane using an adhesive. This enhances the mechanical properties of the composite electrolyte membrane, and when the protective film contacts the lithium metal anode, it enables Li... + Uniform deposition on the negative electrode reduces lithium dendrite formation and the risk of being punctured by lithium dendrites, thus improving the overall performance of the composite electrolyte membrane and facilitating continuous production and large-scale rapid mass production of the composite electrolyte membrane.

[0160] It should be noted that the protective film provided in this application embodiment may not be bonded to at least one surface of the solid electrolyte membrane, but rather the protective film may be bonded to one side surface of the negative electrode using an adhesive. In this way, when assembling the battery, the protective film is placed between the negative electrode and the solid electrolyte membrane, allowing the Li... + The lithium dendrites are uniformly dispersed on the surface of the negative electrode to reduce their formation, making the solid electrolyte membrane less susceptible to being pierced by the lithium dendrites generated on the negative electrode. The preparation method is as follows: S207. Mix the non-fibrous binder and multiple lithium metal stabilizing particles to form a mixed powder; S208. Perform at least one second calendering treatment on the mixed powder at a temperature higher than the melting point of the non-fibrous binder, followed by cooling treatment to form a protective film; S209. Adhere the protective film to one side surface of the negative electrode using an adhesive.

[0161] Alternatively, the protective film provided in this application embodiment may not be combined with any structure, but rather formed separately and placed between the solid electrolyte membrane and the negative electrode. When assembled into a battery, the protective film can prevent the solid electrolyte membrane from contacting the negative electrode and causing side reactions, thus protecting Li + The uniform dispersion on the negative electrode surface reduces lithium dendrite formation and makes it less susceptible to being pierced by lithium dendrites generated on the negative electrode. The preparation method is as follows: S207. Mix the non-fibrous binder and multiple lithium metal stabilizing particles to form a mixed powder; S208. Perform at least one second calendering treatment on the mixed powder at a temperature higher than the melting point of the non-fibrous binder, and then perform a cooling treatment to form a protective film.

[0162] In step 206, the adhesive may include glue or the like.

[0163] battery cell

[0164] Thirdly, embodiments of this application provide a single battery cell. The single battery cell provided in this application includes a positive electrode, a negative electrode, and a composite electrolyte membrane, with the composite electrolyte membrane stacked between the positive and negative electrodes. This composite electrolyte membrane is the same as described in the embodiments of the above application. Figure 1 The composite electrolyte membrane 1 in the middle.

[0165] Of course, the battery cell provided in this application embodiment may also include a positive electrode, a composite negative electrode, and a solid electrolyte membrane. The composite negative electrode includes a negative electrode and a protective film, with the protective film covering one surface of the negative electrode. The solid electrolyte membrane is stacked between the positive electrode and the protective film of the composite negative electrode. The protective film is as described in the above application embodiment. Figure 2 The composite electrolyte membrane 12 in the middle.

[0166] Of course, the battery cell provided in this application embodiment may also include a positive electrode, a negative electrode, a solid electrolyte membrane, and a protective film, with the solid electrolyte membrane stacked between the positive electrode and the protective film, and the protective film stacked between the solid electrolyte membrane and the negative electrode. The protective film is as described in the above application embodiment. Figure 2 The composite electrolyte membrane 12 in the middle.

[0167] Because the battery cell in this application embodiment contains the features described in the above-described embodiment of this application. Figure 1 The composite electrolyte membrane 1 or protective membrane 12 are used, therefore, the short-circuit rate of the battery cells in the embodiments of this application is reduced, the cycle performance is significantly improved, and the electrochemical performance such as the safety of the battery cells is also significantly improved.

[0168] In this application, a battery cell refers to the basic unit that realizes the interconversion of chemical energy and electrical energy, and is also the smallest unit that makes up a battery. There can be multiple battery cells, which can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells are connected in both series and parallel. Multiple battery cells can be directly connected in series, parallel, or in a mixed configuration; alternatively, multiple battery cells can first be connected in series, parallel, or in a mixed configuration to form a battery module, and then multiple battery modules can be connected in series, parallel, or in a mixed configuration to form a whole. A battery module can contain multiple battery cells, and the specific number of battery cells can be adjusted according to the application of the battery module. Furthermore, battery cells or battery modules can be assembled into a battery pack, that is, a battery pack can contain multiple battery cells or multiple battery modules, and the specific number of battery cells or battery modules contained in the battery pack can be adjusted according to the application of the battery pack.

[0169] There are no particular restrictions on the shape of the battery cell; it can be cylindrical, flat, cuboid, or any other shape. As an example, the battery cell 30 can be as follows: Figure 8 The solid-state battery cell shown has a square structure.

[0170] Figure 9Exploded views of a battery cell 30 provided in some embodiments of this application. Please refer to... Figure 9 The outer packaging of the battery cell 30 may include a housing 21 and a cover plate 22. The housing 21 may include a bottom plate and side plates connected to the bottom plate, the bottom plate and side plates forming a receiving cavity, and the housing 21 has an opening communicating with the receiving cavity. The cover plate 22 is used to cover the opening to close the receiving cavity. (This is an embodiment of the application.) Figure 1 The composite electrolyte membrane 1 is encapsulated within the containment cavity.

[0171] Figure 10 This is a schematic diagram showing the composite electrolyte membrane 1 stacked between the positive electrode 102 and the negative electrode 103 according to some embodiments of this application.

[0172] In practical applications, the positive electrode 102 may include a positive electrode current collector and a positive electrode active material layer bonded to the positive electrode current collector. The positive electrode active material layer may be disposed on the surface of the positive electrode current collector, or, when the positive electrode current collector has a porous structure, the positive electrode active material layer may be embedded within the positive electrode current collector. The positive electrode current collector is typically a structure or component capable of collecting current, and it can be made of various materials suitable for use as electrochemical energy storage devices. As an example, the positive electrode current collector is typically sheet-like, and its material may include, but is not limited to, metal foil, and more specifically, nickel foil, aluminum foil, etc.

[0173] As in the example, the positive electrode 102 can be a positive electrode sheet, that is, the positive electrode current collector is sheet-shaped and has two opposing surfaces, and the positive electrode active material layer is disposed on one or both surfaces of the sheet-shaped positive electrode current collector.

[0174] The positive electrode active material layer in positive electrode 102 may contain components such as positive electrode active material, conductive agent, and binder. The types and amounts of positive electrode active material, conductive agent, and binder are not specifically limited and can be determined according to actual needs.

[0175] As an example, the positive electrode active material may include one or more combinations of lithium iron phosphate positive electrode materials, ternary positive electrode materials, and lithium-rich manganese positive electrode materials.

[0176] As an example, the adhesive may include one or more of the following: polyvinylidene chloride, soluble polytetrafluoroethylene, styrene-butadiene rubber, hydroxypropyl methylcellulose, methylcellulose, carboxymethylcellulose, polyvinyl alcohol, acrylonitrile copolymer, sodium alginate, chitosan and chitosan derivatives.

[0177] As an example, conductive agents may include one or more of the following: graphite, carbon black, acetylene black, graphene, carbon fiber, C60, and carbon nanotubes.

[0178] In addition, the positive electrode 102 can also be a positive electrode membrane, which can be a membrane composed of components such as positive electrode active material, conductive agent and binder.

[0179] In practical applications, the negative electrode 103 may include a negative electrode current collector and a negative electrode active material layer bonded to the negative electrode current collector, the negative electrode active material layer being bonded to the surface of the negative electrode current collector. Of course, when the negative electrode current collector has a porous structure, the negative electrode active material layer may also be embedded within the porous structure of the negative electrode current collector. This negative electrode current collector is typically a structure or component capable of collecting current, and it can be made of various materials suitable for use as electrochemical energy storage devices. As an example, the negative electrode current collector is typically sheet-like, and its material may include, but is not limited to, metal foil, and more specifically, copper foil, etc.

[0180] As an example, the negative electrode 103 is a negative electrode sheet, that is, the negative electrode current collector is sheet-shaped and has two opposing surfaces. The negative electrode active material layer is bonded to one or both surfaces of the sheet-shaped negative electrode current collector.

[0181] The negative electrode active material layer in negative electrode 103 may contain components such as negative electrode active material, conductive agent, and binder. The types and contents of negative electrode active material, conductive agent, and binder are not specifically limited and can be selected and controlled according to actual needs.

[0182] As an example, the negative electrode active material may include one or more combinations of carbon-based materials and silicon-based materials.

[0183] As an example, the adhesive may include one or more combinations of soluble styrene butadiene rubber (SBR), sodium carboxymethyl cellulose (CMC-Na), and polyacrylic acid (PAA).

[0184] As an example, conductive agents may include one or more of the following: graphite, carbon black, acetylene black, graphene, carbon fiber, C60, and carbon nanotubes.

[0185] In addition, the negative electrode 103 can also be a lithium metal negative electrode or a lithium indium alloy negative electrode.

[0186] The battery cells provided in this application have significantly improved cycle stability, reduced short-circuit rate, good electrochemical performance, and high safety.

[0187] Battery

[0188] Fourthly, embodiments of this application provide a battery, which includes a battery cell. The battery cell described in the embodiments of this application is the same as the battery cell described above.

[0189] In some embodiments of this application, battery 40 can be a solid-state battery, which is a battery that uses solid electrodes and a solid electrolyte. Specifically, solid-state batteries can include all-solid-state batteries, semi-solid-state batteries, and quasi-solid-state batteries, etc. Solid-state batteries come in many different forms, including but not limited to any one of the following: battery cells, battery modules, and battery packs.

[0190] Figure 11 Exploded views of the battery 40 provided for some embodiments of this application. Please refer to... Figure 11 The battery 40 may include a housing 401 and a battery cell 30, with the battery cell 30 housed within the housing 401. The housing 401 is a component that provides housing space for the battery cell 30, and the housing 401 may have various structures.

[0191] In some embodiments, the housing 401 may include a housing body 4011 and a housing cover 4012, which cover each other and together define a receiving space for accommodating the battery cell 30. Optionally, the housing body 4011 may be a hollow structure with one end open, and the housing cover 4012 may be a plate-like structure that covers the open side of the housing body 4011.

[0192] In battery 40, multiple battery cells 30 can be directly connected in series, parallel, or in a mixed manner, and then the entire assembly of multiple battery cells 30 is housed within housing 401. Alternatively, battery 40 can also be a battery module composed of multiple battery cells 30 first connected in series, parallel, or in a mixed manner, and then multiple battery modules are connected in series, parallel, or in a mixed manner to form a whole, which is also housed within housing 401. Battery 40 may also include other structures, such as a busbar component (…). Figure 11 (Not shown in the image), the busbar component can be used to realize electrical connection between multiple battery cells 30.

[0193] The battery provided in this application embodiment has significantly improved cycle stability, reduced short-circuit rate, good electrochemical performance, and high safety.

[0194] Electrical appliances

[0195] Fifthly, embodiments of this application provide an electrical device that includes the battery 40 described in the embodiments above, and may further be a solid-state battery. The battery 40 can be used as a power source for the electrical device, or as an energy storage unit for the electrical device.

[0196] The electrical device in this application embodiment may include, but is not limited to, mobile devices (e.g., mobile phones, laptops, etc.), electric vehicles (e.g., pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc. The electrical device can be configured with individual battery cells, battery modules, or battery packs according to its usage requirements.

[0197] For ease of explanation, the following embodiments will be described using a vehicle 50 as an example of an electrical device according to an embodiment of this application.

[0198] Figure 12 This is a structural schematic diagram of a vehicle 50 provided in some embodiments of this application. Please refer to... Figure 12 The vehicle 50 has a battery 40 installed inside. The battery 40 can be located at the bottom, front or rear of the vehicle 50. The battery 40 can be used to power the vehicle 50. For example, the battery 40 can be used as the operating power source of the vehicle 50, or the battery 40 can also be used as the driving power source of the vehicle 50, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 50.

[0199] like Figure 12 As shown, the vehicle 50 may also include a controller 501 and a motor 502. The controller 501 is used to control the battery 40 to supply power to the motor 502, for example, to meet the power requirements of the vehicle 50 during startup, navigation and driving.

[0200] The electrical device provided in this application embodiment has high safety and long standby and battery life.

[0201] Energy storage devices

[0202] Sixthly, embodiments of this application also provide an energy storage device, which includes the battery 40 described in the above application embodiment, and may further be a solid-state battery. This battery can be used as an energy storage unit of the energy storage device to improve the capacity and lifespan of the energy storage device.

[0203] The energy storage devices in this application embodiment may include, but are not limited to, large-scale energy storage power stations, such as large-scale battery energy storage power stations, stand-alone grid-type energy storage power stations, and pumped storage power stations.

[0204] The energy storage device provided in this application embodiment has good safety and a long service life.

[0205] Example

[0206] The following describes embodiments of this application. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in the art or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0207] 1. Examples of Electrolyte Membranes and Their Preparation Methods

[0208] Example A1

[0209] This embodiment provides a composite electrolyte membrane and its preparation method.

[0210] The composite electrolyte membrane of this embodiment includes: a solid electrolyte membrane and a protective film covering one side surface of the solid electrolyte membrane.

[0211] Among them, solid electrolyte membranes include Li 5.4 PS 4.5 Cl 1.5 And PTFE, PTFE accounts for Li 5.4 PS 4.5 Cl 1.5 And 10% of the total mass of PTFE, Li 5.4 PS 4.5 Cl 1.5 The particle size is 10 μm.

[0212] The protective film consists of LiF and PA, with PA accounting for 10% of the total mass of LiF and PA, and the particle size of LiF is 0.01 μm.

[0213] The preparation method of the composite electrolyte membrane in this embodiment includes the following steps:

[0214] S1: Li 5.4 PS 4.5 Cl 1.5 After being mixed with PTFE and fiberized in a high-intensity mixer at a speed of 3000 rpm for 100 min, it is then subjected to a hot rolling process in a roll press at a temperature of 50℃, a speed of 10 rpm, a horizontal rolling pressure of 10t, and a vertical rolling pressure of 10t to form a solid electrolyte membrane.

[0215] S2: Mix LiF and PA, electrostatically spray them onto the surface of a solid electrolyte membrane under N2 pressure of 1MPa, nozzle diameter of 1.2mm and voltage of 90KV, then perform a flat hot pressing at 200℃ and pressure of 10MPa, followed by cooling treatment at 25℃ to form a composite electrolyte membrane.

[0216] Example A2

[0217] This embodiment A2 provides a composite electrolyte membrane and its preparation method. The composite electrolyte membrane provided in this embodiment A2 differs from the composite electrolyte membrane provided in embodiment A1 in that Li... 5.4 PS 4.5 Cl 1.5 The mass ratio is different from that of PTFE, but everything else is the same.

[0218] Specifically, in embodiment A2, PTFE accounts for a certain percentage of Li. 5.4 PS 4.5 Cl 1.5 And 20% of the total mass of PTFE.

[0219] Example A3

[0220] This embodiment A3 provides a composite electrolyte membrane and its preparation method. The composite electrolyte membrane provided in this embodiment A3 differs from the composite electrolyte membrane provided in embodiment A1 in that Li... 5.4 PS 4.5 Cl 1.5 The particle size is different, but everything else is the same.

[0221] Specifically, in embodiment A3, Li 5.4 PS 4.5 Cl 1.5 The particle size is 100 μm.

[0222] Example A4

[0223] This embodiment A4 provides a composite electrolyte membrane and its preparation method. The composite electrolyte membrane provided in this embodiment A4 differs from the composite electrolyte membrane provided in embodiment A1 in that the fiberization treatment and hot rolling parameters are different; otherwise, they are the same.

[0224] Specifically, in Example A4, the fiberization process is carried out at a speed of 8000 rpm for 200 min; the hot rolling temperature is 150°C, the speed is 50 rpm, the horizontal calendering pressure is 80t, and the vertical calendering pressure is 80t.

[0225] Example A5

[0226] This embodiment A5 provides a composite electrolyte membrane and its preparation method. The composite electrolyte membrane provided in this embodiment A5 differs from the composite electrolyte membrane provided in embodiment A1 in that the mass ratio of LiF to PA is different; otherwise, they are the same.

[0227] Specifically, in Example A5, PA accounts for 15% of the total mass of LiF and PA.

[0228] Example A6

[0229] This embodiment A6 provides a composite electrolyte membrane and its preparation method. The composite electrolyte membrane provided in this embodiment A6 differs from the composite electrolyte membrane provided in embodiment A1 in that the mass ratio of LiF to PA is different; otherwise, they are the same.

[0230] Specifically, in Example A6, PA accounts for 20% of the total mass of LiF and PA.

[0231] Example A7

[0232] This embodiment A7 provides a composite electrolyte membrane and its preparation method. The composite electrolyte membrane provided in this embodiment A7 differs from the composite electrolyte membrane provided in embodiment A1 in that the particle size of LiF is different, but everything else is the same.

[0233] Specifically, the particle size of LiF in Example A7 is 0.1 μm.

[0234] Examples A8 to A9

[0235] Examples A8 to A9 provide a composite electrolyte membrane and its preparation method. The composite electrolyte membranes provided in Examples A8 to A9 differ from those provided in Example A1 in that the parameters of the electrostatic spraying process and the flat plate hot-pressing treatment are different; otherwise, they are the same.

[0236] Specifically, in step S1 of embodiment A8, the N2 pressure of the electrostatic spraying process is 1.6MPa, the nozzle diameter is 1.3mm, the voltage is 96KV, and the temperature of the flat plate hot pressing is 230℃ and the pressure is 40MPa.

[0237] In step S1 of Example A9, the N2 pressure of the electrostatic spraying process is 2.0 MPa, the nozzle diameter is 1.5 mm, the voltage is 100 KV, and the temperature of the flat plate hot pressing is 250 °C and the pressure is 80 MPa.

[0238] Comparative Example A1

[0239] Comparative Example A1 provides a solid electrolyte membrane and its preparation method.

[0240] The solid electrolyte membrane and its preparation method in Comparative Example A1 are the same as those in Example A1, except that there is no protective membrane.

[0241] Comparative Example A2

[0242] Comparative Example A2 provides a composite electrolyte membrane and its preparation method.

[0243] The composite electrolyte membrane and its preparation method in Comparative Example A2 differ from those in Example A1 in that the mass ratio of LiF to PA is different, while the rest are the same.

[0244] Specifically, in Comparative Example A2, PA accounts for 80% of the total mass of LiF and PA.

[0245] Comparative Example A3

[0246] Comparative Example A3 provides a composite electrolyte membrane and its preparation method.

[0247] The composite electrolyte membrane and its preparation method in Comparative Example A3 differ from those in Example A1 in that the LiF particle size is different, but everything else is the same.

[0248] Specifically, the particle size of LiF is 5 μm.

[0249] 2. Characterization and related performance tests of the electrolyte membranes in each embodiment and comparative example:

[0250] The relevant characteristic parameters of the electrolyte membranes provided in Examples A1 to A9 and Comparative Examples A1 to A3 above, and the relevant characteristic detection of the electrolyte membranes provided in Examples A1 to A9 and Comparative Examples A1 to A3 below were performed according to the following methods, and the results are summarized in Table 1.

[0251] The detection methods for the relevant characteristics of the electrolyte membrane in Table 1 are as follows:

[0252] (1). Particle size detection method: The detection shall be carried out in accordance with the method and procedure in GB / T16418.

[0253] (2). Method for detecting the mass percentage of each component in the electrolyte membrane: Weigh each component using a high-precision balance. The ratio of the mass of each component to the total mass is the mass percentage of that component in the electrolyte membrane.

[0254] Table 1

[0255]

[0256]

[0257] 3. Solid-state battery cell examples

[0258] Examples B1 to B9 and Comparative Examples B1 to B3

[0259] Examples B1 to B9 and Comparative Examples B1 to B3 each provide a solid-state battery cell, each solid-state battery cell being formed of a positive electrode film, a composite electrolyte film, and a negative electrode sheet.

[0260] The solid-state battery cells in Examples B1 to B9 and Comparative Examples B1 to B3 are assembled as follows:

[0261] (1). Preparation of the positive electrode film:

[0262] In a room temperature (25°C) environment, ternary cathode material and Li 5.4 PS 4.5 Cl 1.5 Conductive carbon black (SP) and PTFE powder were weighed in a mass ratio of 70:25:3:2 and placed in a high-speed disperser. After being dispersed and stirred at 8000 rpm for 20 minutes, the mixture was placed in a roller press and rolled at a heating temperature of 100℃ and a speed of 3 rpm to form a positive electrode film.

[0263] (2). Preparation of negative electrode sheet:

[0264] Lithium metal is used as the negative electrode.

[0265] (3) Assembly of solid-state battery cells:

[0266] The prepared positive electrode film is placed in a mold, and the prepared composite electrolyte film and lithium metal negative electrode sheet are sequentially stacked on one surface of the positive electrode film. Then, it is cold-pressed under a pressure of 200MPa to obtain a solid-state battery cell.

[0267] 4. Electrochemical performance testing of solid-state battery cells in each embodiment and comparative example:

[0268] The solid-state battery cells provided in Examples B1 to B9 and Comparative Examples B1 to B3 were subjected to the relevant electrochemical performance tests shown in Table 2 below, and the test results are shown in Table 2.

[0269] The relevant performance testing methods for solid-state battery cells are listed in Table 2.

[0270] (1). Ionic conductivity test:

[0271] The ionic conductivity of the composite electrolyte membrane was tested using an AC impedance analyzer at room temperature.

[0272] The specific steps are as follows: at a constant temperature of 25±0.1℃, 10 7 The impedance of the composite electrolyte membrane was tested at an AC impedance of Hz, and the ionic conductivity was calculated by combining the measured thickness of the composite electrolyte membrane.

[0273] (2). Protective film thickness test:

[0274] The protective film thickness of the composite electrolyte membrane cross-section was measured using a scanning electron microscope (SEM).

[0275] (3). Solid electrolyte membrane thickness test:

[0276] The thickness of the solid electrolyte membrane was measured using a micrometer.

[0277] (4) Charge-discharge cycle performance test of solid-state battery cells:

[0278] The test was conducted using a prototype battery mold at a temperature of 45°C.

[0279] The specific steps are as follows: First, charge the battery at a constant current of 0.2C to 4.3V, then charge it at a constant voltage until the current is cut off at 0.05C. After resting for 20 minutes, discharge it at a current of 0.2C to 2.7V, and then rest for another 20 minutes to complete one cycle. Repeat this charge-discharge cycle test and record the capacity retention rate, number of charge-discharge cycles, and specific capacity of the solid-state battery cells.

[0280] Solid-state battery cells assembled from samples prepared in Examples B1 to B9 and Comparative Examples B1 to B3 were tested to obtain data on composite electrolyte membrane thickness, protective membrane thickness, ionic conductivity of composite electrolyte membrane, 0.2C capacity retention, cycle number at 80% 0.2C capacity retention, and specific capacity, as shown in Table 2 below.

[0281] Table 2

[0282]

[0283]

[0284] First, based on the data in Tables 1 to 2, and comparing Examples B1 to B9 in Table 2 with Comparative Examples B1 to B3, the solid-state battery cells can cycle approximately 200 to 400 times at 0.2C with a capacity retention rate of 70% to 90%, and there is no short-circuit failure. That is, the solid-state battery cells have a high 0.2C capacity retention rate, a high number of cycles at 0.2C capacity retention rate of 80%, and good cycle stability.

[0285] Secondly, comparing Examples B1 and B2 in Table 2, it can be seen that as the PTFE content in the solid electrolyte membrane increases, i.e., Li 5.4 PS 4.5 Cl 1.5 With the reduction in content, the number of cycles of solid-state battery cells at 0.2C with 80% capacity retention decreases slightly, but the difference is not significant.

[0286] Comparing Examples B1 and B3 in Table 2, it can be seen that as the PTFE particle size in the solid electrolyte membrane increases, the number of cycles of the solid battery cell at 0.2C capacity retention of 80% decreases slightly, but the difference is not significant.

[0287] Comparing Examples B1 and B4 in Table 2, it can be seen that as the degree of fibrosis and hot rolling is increased, the number of cycles of solid-state battery cells at 80% capacity retention at 0.2C increases slightly, but the difference is not significant.

[0288] Comparing Examples B1, B5, and B6 in Table 2, it can be seen that as the PA content in the protective film increases, i.e., the LiF content decreases, the number of cycles of the solid-state battery cell at 80% capacity retention at 0.2C decreases slightly, but the difference is not significant.

[0289] Comparing Examples B1 and B7 in Table 2, it can be seen that as the LiF particle size in the protective film increases, the number of cycles of the solid-state battery cell at 0.2C capacity retention of 80% decreases slightly, but the difference is not significant.

[0290] Comparing Examples B1 with Examples B8 and B9 in Table 2, it can be seen that as the electrostatic spraying and flat hot pressing processes are enhanced during the preparation of the protective film, the protective film thickness is thinner, resulting in a thinner composite electrolyte membrane. The number of cycles of the solid-state battery cell at 80% capacity retention at 0.2C decreases slightly, but the difference is not significant.

[0291] In contrast, the solid-state battery cell produced without a protective film in Comparative Example B1 failed to short-circuit after only 52 cycles, indicating poor performance.

[0292] Comparing Example B1 and Comparative Example B2 in Table 2, it can be seen that as the PA content is too high, the LiF content is too low, and the solid-state battery cell fails to short-circuit after only 60 cycles, resulting in poor performance.

[0293] Comparing Example B1 and Comparative Example B3 in Table 2, it can be seen that as the LiF particle size becomes too large, the solid-state battery cell experiences short-circuit failure after only 150 cycles, resulting in poor performance.

[0294] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of this application, and they should all be covered by the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A composite electrolyte membrane, characterized in that, It includes a solid electrolyte membrane and a protective membrane. The protective membrane covers one side surface of the solid electrolyte membrane. The protective membrane includes a non-fibrous binder and a plurality of lithium metal stabilizing particles, which are bonded together by the non-fibrous binder.

2. The composite electrolyte membrane according to claim 1, characterized in that, The lithium metal stabilizing particles include at least one of lithium fluoride, lithium nitride, lithium lanthanum zirconium tantalum oxide, and lithium lanthanum zirconium oxide.

3. The composite electrolyte membrane according to claim 2, characterized in that, The lithium metal stabilizing particles have an ionic conductivity of 0.001 mS / cm to 10 mS / cm; and / or, The electronic conductivity of the lithium metal stabilizing particles is less than 10. -6 mS / cm; and / or, The particle size of the lithium metal stabilizing particles is less than 1 μm.

4. The composite electrolyte membrane according to any one of claims 1 to 3, characterized in that, The non-fibrous binder accounts for 0.01% to 49.9% of the total mass of the non-fibrous binder and the lithium metal stabilizing particles.

5. The composite electrolyte membrane according to any one of claims 1 to 4, characterized in that, The non-fibrous adhesive includes at least one of polyamide, polyethylene, polypropylene, polystyrene, polymethyl methacrylate, polyvinyl chloride, polycarbonate, polyurethane, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polyethylene oxide, nylon, polyethylene terephthalate, and polyoxymethylene.

6. The composite electrolyte membrane according to any one of claims 1 to 5, characterized in that, The solid electrolyte membrane comprises multiple solid electrolyte particles and a fibrous binder, the fibrous binder extending throughout the solid electrolyte membrane. The fibrous binder is wound around the surface of at least one of the solid electrolyte particles; and / or The fibrous binder forms a network structure in the solid electrolyte membrane.

7. The composite electrolyte membrane according to claim 6, characterized in that, The solid electrolyte particles include at least one of sulfide solid electrolyte particles and halide solid electrolyte particles; and / or, The solid electrolyte particles have a particle size of 0.1 μm to 100 μm; and / or, The fibrous binder includes polytetrafluoroethylene.

8. The composite electrolyte membrane according to any one of claims 1 to 7, characterized in that, The thickness of the protective film is less than or equal to 5 μm.

9. The composite electrolyte membrane according to any one of claims 1 to 8, characterized in that, The composite electrolyte membrane has an ionic conductivity of 0.1 mS / cm to 100 mS / cm; and / or, The thickness of the composite electrolyte membrane is less than or equal to 200 μm; and / or, The tensile strength of the composite electrolyte membrane is 0.1 MPa to 5 MPa.

10. A method for preparing a composite electrolyte membrane, characterized in that, Includes the following steps: Formation of a solid electrolyte membrane; The composite electrolyte membrane is formed by mixing a non-fibrous binder and multiple lithium metal stabilizing particles and coating one side surface of the solid electrolyte membrane.

11. The method for preparing the composite electrolyte membrane according to claim 10, characterized in that, The process of mixing a non-fibrous binder and multiple lithium metal stabilizing particles and coating one side surface of the solid electrolyte membrane includes: The non-fibrous binder and the plurality of lithium metal stabilizing particles are mixed to form a mixed powder; The mixed powder is sprayed onto the surface of the solid electrolyte membrane, calendered at a temperature higher than the melting point of the non-fibrous binder, and then cooled.

12. The method for preparing the composite electrolyte membrane according to claim 11, characterized in that, The spraying is electrostatic spraying, wherein the nitrogen pressure for electrostatic spraying is 0.1 MPa to 2 MPa; and / or, The nozzle diameter for electrostatic spraying is 1mm to 1.5mm; and / or, The voltage for electrostatic spraying is 80KV to 100KV.

13. The method for preparing the composite electrolyte membrane according to claim 10, characterized in that, The process of mixing a non-fibrous binder and multiple lithium metal stabilizing particles and coating one side surface of the solid electrolyte membrane includes: The non-fibrous binder and the plurality of lithium metal stabilizing particles are mixed to form a mixed powder; The mixed powder is calendered at a temperature higher than the melting point of the non-fibrous binder, and then cooled to form a protective film. The protective film is bonded to one side surface of the solid electrolyte membrane to form the composite electrolyte membrane.

14. A single battery cell, characterized in that, The composite electrolyte membrane includes a positive electrode, a negative electrode, and a composite electrolyte membrane prepared by the method of preparing the composite electrolyte membrane according to any one of claims 1 to 9 or according to any one of claims 10 to 13, wherein the protective membrane is located between the composite electrolyte membrane and the negative electrode.

15. A battery, characterized in that, Includes the battery cell according to claim 14.

16. An electrical appliance, characterized in that, Includes the battery according to claim 15.

17. An energy storage device, characterized in that, Includes the battery according to claim 15.

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