Solid-state electrolyte membrane and preparation method therefor, electrical battery cell, battery, and use thereof

Abstract

The present application relates to the technical field of batteries, and discloses a solid-state electrolyte membrane and a preparation method therefor, an electrical battery cell, a battery, and a use thereof. The solid-state electrolyte membrane at least comprises a fiber-free thermoplastic polymer and multiple solid electrolyte particles, the solid electrolyte particles being bonded by means of the fiber-free thermoplastic polymer. The tensile strength of the solid-state electrolyte membrane is 0.1 MPa-50 MPa, and / or the ionic conductivity of the solid-state electrolyte membrane is 0.1 mS / cm-100 mS / cm. The solution of the present application enhances the mechanical properties of the solid-state electrolyte membrane, and does not affect the ionic conductivity of the solid-state electrolyte membrane, thereby improving the cycling and safety of the solid-state electrolyte membrane.

Description

Solid electrolyte membranes and their preparation methods, battery cells, batteries and their applications

[0001] This application claims priority to Chinese Patent Application No. 202411812915.2, filed on December 10, 2024, entitled "Solid Electrolyte Membrane and Preparation Method Thereof, Electrolytic Battery Cell, Battery and Application Thereof", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of battery technology, specifically to a solid electrolyte membrane and its preparation method, an electrical battery cell, a battery and its application. Background Technology

[0003] Solid-state batteries are batteries with a solid electrolyte, offering higher energy density and better safety compared to traditional liquid batteries. Solid-state batteries feature a solid electrolyte membrane, which is an indispensable component separating the positive and negative electrodes; its performance is one of the key factors affecting the overall performance of the solid-state battery.

[0004] Currently, solid electrolyte membranes are prepared using either wet coating or dry film deposition processes. However, wet coating processes require the introduction of organic solvents, which can negatively impact the performance of solid electrolyte membranes. Therefore, dry film deposition processes are receiving increasing research and application because they can reduce costs while avoiding the adverse effects of organic solvents on solid electrolyte membranes.

[0005] However, the mechanical properties of solid electrolyte membranes produced by the commonly used dry film-forming process are usually poor, such as tensile strength. This makes the solid electrolyte membranes prone to cracking and breakage during the preparation process. At the same time, it is also impossible to prevent the dendrites of the negative electrode from piercing the solid electrolyte membrane, which leads to short circuit failure of the battery cells. This not only seriously affects the overall performance of the battery, but also hinders industrial production. Summary of the Invention

[0006] In view of the above problems, this application provides a solid electrolyte membrane and its preparation method, an electric battery cell, a battery and its application, aiming to solve the problem that the mechanical properties such as tensile strength of solid electrolyte membranes produced by traditional dry processes are poor, which makes the solid electrolyte membrane prone to cracking and breakage during the preparation process, and also cannot suppress the dendrites of the negative electrode from piercing the solid electrolyte membrane.

[0007] In a first aspect, embodiments of this application provide a solid electrolyte membrane, comprising at least a non-fibrous thermoplastic polymer and a plurality of solid electrolyte particles, wherein each of the solid electrolyte particles is bonded together by the non-fibrous thermoplastic polymer;

[0008] Wherein, the tensile strength of the solid electrolyte membrane is 0.1 MPa to 50 MPa; and / or,

[0009] The ionic conductivity of the solid electrolyte membrane is 0.1 mS / cm to 100 mS / cm.

[0010] The solid electrolyte membrane provided in this application embodiment coats the surface of multiple solid electrolyte particles with a non-fibrous thermoplastic polymer, forming an effective bond. This improves the tensile strength and other mechanical properties of the solid electrolyte membrane. Simultaneously, the solid electrolyte particles not coated by the non-fibrous thermoplastic polymer still achieve good lithium-ion (Li) ionization. + The transmission process does not affect the ionic conductivity of the solid electrolyte membrane, thus improving the overall performance of the solid electrolyte membrane.

[0011] In some embodiments, the non-fibrous thermoplastic polymer comprises 0.1 wt% to 20 wt% of the solid electrolyte membrane; and / or,

[0012] The total mass ratio of the solid electrolyte particles to the non-fibrous thermoplastic polymer is 95-99:1-5.

[0013] By setting a slightly higher content of non-fibrous thermoplastic polymer in the solid electrolyte membrane, more surface area of ​​the solid electrolyte particles can be coated in the membrane, resulting in better adhesion. Meanwhile, the portion of the solid electrolyte particles not coated by the non-fibrous thermoplastic polymer still achieves good Li-ion bonding. + This transmission ensures the ionic conductivity of the solid electrolyte membrane.

[0014] In some embodiments, the solid electrolyte membrane further includes a fibrous thermoplastic polymer that extends throughout the solid electrolyte membrane.

[0015] The fibrous thermoplastic polymer is wound around the surface of at least one of the solid electrolyte particles; and / or,

[0016] The fibrous thermoplastic polymer forms a network structure in the solid electrolyte membrane.

[0017] By adding non-fibrous thermoplastic polymers as binders, and fibrous thermoplastic polymers running through the solid electrolyte membrane, the non-fibrous thermoplastic polymers can further enhance the adhesion between multiple solid electrolyte particles. In this way, through the combined action of fibrous and non-fibrous thermoplastic polymers, the mechanical properties of the solid electrolyte membrane, such as tensile strength, are significantly improved without affecting the ionic conductivity of the solid electrolyte membrane, thus greatly improving the overall performance of the solid electrolyte membrane.

[0018] In some embodiments, the total mass percentage of the non-fibrous thermoplastic polymer and the fibrous thermoplastic polymer in the solid electrolyte membrane is 0.1 wt% to 20 wt%.

[0019] By designing the mass percentages of non-fibrous thermoplastic polymers and fibrous thermoplastic polymers in the solid electrolyte membrane, effective bonding can be formed between multiple solid electrolyte particles without affecting the ionic conductivity of the solid electrolyte membrane.

[0020] In some embodiments, the fibrous thermoplastic polymer comprises 0.01% to 49% of the total mass of the non-fibrous thermoplastic polymer and the fibrous thermoplastic polymer; and / or,

[0021] The mass ratio of the total mass of the solid electrolyte particles, the non-fibrous thermoplastic polymer, and the fibrous thermoplastic polymer is 95–99:0.5–3:0.5–3; and / or,

[0022] The fibrous thermoplastic polymer includes polytetrafluoroethylene.

[0023] By designing the weight ratio of multiple solid electrolyte particles, non-fibrous thermoplastic polymers, and fibrous thermoplastic polymers, effective bonding can be formed between multiple solid electrolyte particles without affecting the ionic conductivity of the solid electrolyte membrane.

[0024] In some embodiments, the non-fibrous thermoplastic polymer includes at least one selected from polyamide, polyethylene, polypropylene, polystyrene, polymethyl methacrylate, polyvinyl chloride, nylon, polycarbonate, polyurethane, polyethylene terephthalate, and polyoxymethylene.

[0025] By selecting non-fibrous thermoplastic polymers that melt when heated to temperatures above their melting point and then rapidly solidify upon cooling as binders, multiple solid electrolyte particles can be well bonded in the molten state. This significantly improves the tensile strength and other mechanical properties of the solid electrolyte membrane without affecting its ionic conductivity, thus greatly enhancing the overall performance of the solid electrolyte membrane.

[0026] In some embodiments, the solid electrolyte particles include at least one of sulfide solid electrolyte particles and halide solid electrolyte particles; and / or,

[0027] The particle size of the solid electrolyte particles is 0.1 μm to 100 μm;

[0028] The sulfide solid electrolyte particles include Li 5.4 PS 4.5 Cl 1.5 Li3PS4(LPS), Li10 GeP2S 12 At least one of (LGPS), Li6PS5Cl (LPSCl), Li6PS5I (LPSI), and Li6PS5Br (LPSBr);

[0029] The halide solid electrolyte particles include Li3InCl6, Li3YCl6, Li3ScCl6, Li3TaCl6, Li3ZrCl6, and Li3Y. 1-x In x At least one of Cl6 (0≤x≤1), Li3YbCl6, and Li3HoCl6.

[0030] Solid electrolyte membranes can have better electrochemical performance through sulfide solid electrolyte particles and / or halide solid electrolyte particles.

[0031] In some embodiments, the thickness of the solid electrolyte membrane is less than or equal to 200 μm.

[0032] By setting the thickness of the solid electrolyte membrane to be relatively thin, the battery using this solid electrolyte membrane can achieve high energy density and good performance.

[0033] Secondly, embodiments of this application provide a method for preparing a solid electrolyte membrane, comprising the following steps:

[0034] A non-fibrous thermoplastic polymer and multiple solid electrolyte particles are mixed to form a mixture, which is then subjected to at least one first calendering treatment at a temperature higher than the melting point of the non-fibrous thermoplastic polymer, followed by a cooling treatment to obtain the solid electrolyte membrane; wherein the tensile strength of the solid electrolyte membrane is 0.1 MPa to 50 MPa; and / or the ionic conductivity of the solid electrolyte membrane is 0.1 mS / cm to 100 mS / cm.

[0035] The solid electrolyte membrane preparation method provided in this application involves calendering a non-fibrous thermoplastic polymer and multiple solid electrolyte particles at a temperature higher than the melting point of the non-fibrous thermoplastic polymer. The non-fibrous thermoplastic polymer is in a molten state and forms an effective bond between the multiple solid electrolyte particles. The solid electrolyte membrane prepared by this dry process has enhanced mechanical properties such as tensile strength and can effectively prevent negative electrode dendrites from piercing the solid electrolyte membrane, reducing the risk of battery short-circuit failure. It does not affect the ionic conductivity of the solid electrolyte membrane, thus improving battery performance. In addition, this preparation method is simple and easy to implement, which is conducive to industrial production.

[0036] In some embodiments, performing at least one first calendering process at a temperature above the melting point of the non-fibrous thermoplastic polymer includes:

[0037] The mixture is subjected to at least one second calendering treatment at a temperature lower than the melting point of the non-fibrous thermoplastic polymer to obtain an initial solid electrolyte membrane with a thickness of less than or equal to 200 μm.

[0038] The initial solid electrolyte membrane is subjected to the first calendering process at least once at a temperature higher than the melting point of the non-fibrous thermoplastic polymer.

[0039] By mixing multiple solid electrolyte particles and a non-fibrous thermoplastic polymer together, the mixture is first calendered to a target thickness at a temperature below the melting point of the non-fibrous thermoplastic polymer, and then calendered again at a temperature above the melting point of the non-fibrous thermoplastic polymer to melt the polymer, encapsulating and binding the solid electrolyte particles. This dry process further enhances the tensile strength and other mechanical properties of the solid electrolyte membrane, and better mitigates the risk of negative electrode dendrites piercing the solid electrolyte membrane, thus significantly reducing the risk of battery failure. It does not affect the ionic conductivity of the solid electrolyte membrane. Furthermore, the very thin thickness of the solid electrolyte membrane results in excellent battery performance. This preparation method is simple and easy to implement, making it suitable for industrial production.

[0040] In some embodiments, the method for preparing a solid electrolyte membrane includes the following steps:

[0041] The non-fibrous thermoplastic polymer and the plurality of solid electrolyte particles are mixed to obtain an initial mixed material;

[0042] A fibrous thermoplastic polymer is added to the initial mixed material and mixed to obtain a mixture;

[0043] The mixture is subjected to a fiberization treatment to obtain a fiberized mixture; wherein the fiberized thermoplastic polymer runs through the solid electrolyte membrane, and the fiberized thermoplastic polymer is wrapped around the surface of at least one of the solid electrolyte particles; and / or, the fiberized thermoplastic polymer forms a network structure in the solid electrolyte membrane;

[0044] The fibrous mixture is subjected to the first calendering process at least once at a temperature higher than the melting point of the non-fibrous thermoplastic polymer and lower than the melting point of the fibrous thermoplastic polymer, followed by the cooling process, to obtain the solid electrolyte membrane.

[0045] By first fiberizing a mixture of solid electrolyte particles, non-fibrous thermoplastic polymer, and fibrous thermoplastic polymer, the fibrous filaments of the fibrous thermoplastic polymer penetrate the solid electrolyte membrane, initially bonding multiple solid electrolyte particles. Then, calendering is performed at a temperature higher than the melting point of the non-fibrous thermoplastic polymer but lower than its melting point, causing the non-fibrous thermoplastic polymer to melt and encapsulate the solid electrolyte particles, further bonding them. This significantly enhances the tensile strength and other mechanical properties of the solid electrolyte membrane, and more effectively prevents dendrite penetration from the negative electrode, further reducing the risk of battery short-circuit failure. Furthermore, it does not affect the ionic conductivity of the solid electrolyte membrane, resulting in a substantial improvement in battery performance. In addition, this preparation method is simple and easy to implement, facilitating industrial production.

[0046] In some embodiments, after the step of fiberizing the mixture to obtain a fiberized mixture and before the cooling treatment, the following steps are further included:

[0047] The fibrous mixture is subjected to at least one second calendering treatment at a temperature lower than the melting point of the non-fibrous thermoplastic polymer to obtain an initial solid electrolyte membrane with a thickness of less than or equal to 200 μm.

[0048] The initial solid electrolyte membrane is subjected to the first calendering process at least once at a temperature higher than the melting point of the non-fibrous thermoplastic polymer and lower than the melting point of the fibrous thermoplastic polymer.

[0049] By mixing multiple solid electrolyte particles, a non-fibrous thermoplastic polymer, and a fibrous thermoplastic polymer together, the mixture is first subjected to a fibrous treatment. At this point, the fibrous filaments of the fibrous thermoplastic polymer penetrate the solid electrolyte membrane and bind the multiple solid electrolyte particles together. Then, it is calendered to a target thickness at a temperature lower than the melting point of the non-fibrous thermoplastic polymer. Next, it is calendered again at a temperature higher than the melting point of the non-fibrous thermoplastic polymer but lower than the melting point of the fibrous thermoplastic polymer, causing the non-fibrous thermoplastic polymer to melt, encapsulate and bind the solid electrolyte particles, and then cooled. This dry process further enhances the tensile strength and other mechanical properties of the solid electrolyte membrane, and better improves the resistance to dendrite penetration of the solid electrolyte membrane by the negative electrode, thus significantly reducing the risk of battery failure without affecting the ionic conductivity of the solid electrolyte membrane. Furthermore, the very thin thickness of the solid electrolyte membrane results in excellent battery performance. This preparation method is simple and easy to implement, which is beneficial for industrial production.

[0050] Thirdly, embodiments of this application provide an electrical battery cell, including the solid electrolyte membrane described above or the solid electrolyte membrane prepared by the above-described preparation method.

[0051] The battery cells provided in this application have a low risk of short-circuit failure, high safety, and good performance.

[0052] Fourthly, embodiments of this application provide a battery comprising the aforementioned electrical battery cell.

[0053] The battery provided in this application embodiment has a low risk of short-circuit failure, high safety, and good performance.

[0054] Fifthly, embodiments of this application provide an electrical device including the battery described above.

[0055] The electrical device provided in this application embodiment has a low risk of short-circuit failure, high safety, and good performance.

[0056] Sixthly, embodiments of this application provide an energy storage device, including the battery described above.

[0057] The energy storage device provided in this application embodiment has a low risk of short-circuit failure, high safety, and good performance.

[0058] 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

[0059] 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:

[0060] Figure 1 is a schematic diagram of the structure of a solid electrolyte membrane according to some embodiments of this application;

[0061] Figure 2 is a schematic diagram of the structure of a solid electrolyte membrane according to some embodiments of this application;

[0062] Figure 3 is a process flow diagram of the preparation of solid electrolyte membranes according to some embodiments of this application;

[0063] Figure 4 is a process flow diagram of the preparation of solid electrolyte membranes according to some embodiments of this application;

[0064] Figure 5 is a process flow diagram of the preparation of solid electrolyte membranes according to some embodiments of this application;

[0065] Figure 6 is a process flow diagram of the preparation of solid electrolyte membranes according to some embodiments of this application;

[0066] Figure 7 is a schematic diagram of a square-structured battery cell according to some embodiments of this application;

[0067] Figure 8 is a schematic diagram of the exploded structure of an electric battery cell according to some embodiments of this application;

[0068] Figure 9 is a schematic diagram of the structure of the positive electrode, negative electrode and solid electrolyte membrane in some embodiments of this application;

[0069] Figure 10 is a schematic diagram of the exploded structure of a battery according to some embodiments of this application;

[0070] Figure 11 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: 1. Solid electrolyte membrane; 2. Positive electrode; 21. Shell; 22. Cover plate; 3. Negative electrode; 30. Single cell of battery; 40. Battery; 401. Box; 4011. Box body; 4012. Box cover; 50. Vehicle; 501. Controller; 502. Motor. Detailed Implementation

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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).

[0078] 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.

[0079] 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.

[0080] Against the backdrop of energy conservation and emission reduction, new energy technologies are developing rapidly, with breakthroughs and applications in battery technology being one such area. As battery applications become increasingly widespread, especially with the rapid development of electric vehicles in recent years, power batteries have seen rapid growth and a dramatic increase in demand. Simultaneously, battery safety has received increasing attention. Solid-state batteries, compared to traditional liquid batteries, offer higher energy density and better safety, and are considered one of the important future directions for battery development.

[0081] Solid-state batteries are a type of battery that uses solid electrodes (positive and negative electrodes) and a solid electrolyte, where the solid electrolyte can form a solid electrolyte membrane. The solid electrolyte membrane, as an indispensable part separating the positive and negative electrodes, is one of the key factors affecting the overall performance of solid-state batteries.

[0082] There are two main methods for preparing solid electrolyte membranes: wet coating and dry film formation. Current wet coating processes primarily involve high-speed stirring and dispersion of solid electrolyte particles, binders, and organic solvents to create a uniform slurry for coating. However, most solid electrolyte particles are unstable in water, oxygen, and organic solvents. For example, solid electrolyte particles are prone to side reactions with organic solvents, which affects the performance of the solid electrolyte membrane; for instance, the ionic conductivity of the solid electrolyte membrane may not meet requirements.

[0083] Dry film deposition processes for preparing solid-state electrolyte membranes (SEMs) eliminate the need for organic solvents, reducing costs and avoiding their adverse effects. This has led to their increasing research and application. However, current dry film deposition processes generally produce SEMs with poor tensile strength and other mechanical properties. The process is prone to cracking or breakage, and it cannot suppress dendrite penetration of the SEM, posing a risk of short-circuit failure in solid-state batteries. These issues severely impact the overall performance of SEMs and hinder the large-scale, rapid production of dry film deposition processes.

[0084] Currently, the conventional solution to the problem of generally poor tensile strength and other mechanical properties of solid electrolyte membranes prepared by dry film deposition processes is to add additional materials, such as insulating ceramic materials to the solid electrolyte particles and binders. However, insulating ceramic materials cannot effectively improve the adhesion between solid electrolyte particles and binders, resulting in insufficient improvement in the tensile strength and other mechanical properties of the solid electrolyte membrane. Furthermore, inorganic insulating ceramic materials have low ionic conductivity, which, when added, will further reduce the ionic conductivity of the solid electrolyte membrane, leading to a deterioration in the electrochemical performance of the solid-state battery.

[0085] To improve the tensile strength and other mechanical properties of solid electrolyte membranes without reducing their ionic conductivity, research has shown that non-fibrous thermoplastic polymers can remain in a molten state at temperatures above their melting point. Molten non-fibrous thermoplastic polymers exhibit excellent adhesion, enabling effective bonding of solid electrolyte particles. Therefore, using non-fibrous thermoplastic polymers as binders to bond solid electrolyte particles can effectively improve the tensile strength and other mechanical properties of the solid electrolyte membrane without reducing its ionic conductivity, thereby significantly improving the electrochemical performance of solid-state batteries. Based on this research, the following scheme is proposed in this application.

[0086] Solid electrolyte membrane

[0087] In a first aspect, embodiments of this application provide a solid electrolyte membrane. In some embodiments, the solid electrolyte membrane of this application embodiment may be as shown in FIG1, wherein the solid electrolyte membrane 1 comprises at least a non-fibrous thermoplastic polymer and a plurality of solid electrolyte particles, wherein each solid electrolyte particle is bonded together by the non-fibrous thermoplastic polymer; wherein the tensile strength of the solid electrolyte membrane is 0.1 MPa to 50 MPa; and / or, the ionic conductivity of the solid electrolyte membrane is 0.1 mS / cm to 100 mS / cm.

[0088] It should be understood that the statement that a solid electrolyte membrane includes at least a non-fibrous thermoplastic polymer and multiple solid electrolyte particles means that the solid electrolyte membrane may only include a non-fibrous thermoplastic polymer and multiple solid electrolyte particles, or, in addition to including a non-fibrous thermoplastic polymer and multiple solid electrolyte particles, the solid electrolyte membrane may also include other components, without specific limitations here.

[0089] The aforementioned non-fibrous thermoplastic polymers are specifically used as non-fibrous thermoplastic polymer binders. These binders can bond to a large portion of the surface of all solid electrolyte particles, achieving effective bonding of all solid electrolyte particles. As an example, non-fibrous thermoplastic polymers may include one or more combinations of polycarbonate (PC), thermoplastic polyamide elastomers (PA), polyethylene (PE), polypropylene (PP), polystyrene (PS), polymethyl methacrylate (PMMA), polyvinyl chloride (PVC), nylon, polyurethane (PU), polyethylene terephthalate (PET), and polyformaldehyde (POM). These materials can achieve tight bonding between multiple solid electrolyte particles.

[0090] In practical applications, solid electrolyte particles can enable solid electrolyte membranes to achieve better ionic conductivity, thereby giving them better lithium-ion (Li₂) conductivity. +(Transmission function.) The solid electrolyte particles can specifically be solid electrolyte powder particles, with a particle size ranging from 0.1 μm to 100 μm, optionally from 0.5 μm to 20 μm. For example, the particle size of the solid electrolyte powder particles can be 0.5 μm, 1 μm, 5 μm, 10 μm, 15 μm, or 20 μm, etc. This allows for a suitable ionic conductivity in the solid electrolyte membrane, ease of processing, and a relatively thin thickness of the processed solid electrolyte membrane.

[0091] As an example, solid electrolyte particles may include sulfide solid electrolyte particles and / or halide solid electrolyte particles.

[0092] 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 a sulfide solid electrolyte as the electrolyte can improve the electrochemical stability of the solid electrolyte membrane, thereby enhancing the safety performance of solid-state batteries using this solid electrolyte membrane.

[0093] 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 a halide solid electrolyte as the electrolyte enables the solid electrolyte membrane to have strong resistance to oxidation and etching and higher electrochemical stability, thereby improving the safety performance of solid-state batteries using this solid electrolyte membrane.

[0094] In practical applications, the mass ratio of the total mass of multiple solid electrolyte particles to the non-fibrous thermoplastic polymer is 95–99:1–5, optionally 95–97:3–5. For example, the mass ratio of the total mass of multiple solid electrolyte particles to the non-fibrous thermoplastic polymer can be 95:5, 96:4, or 97:3, etc. The non-fibrous thermoplastic polymer allows for better bonding between the multiple solid electrolyte particles, maximizing the tensile strength and other mechanical properties of the solid electrolyte membrane, while ensuring that the amount of non-fibrous thermoplastic polymer is not excessive and does not reduce the ionic conductivity of the solid electrolyte membrane.

[0095] The tensile strength of the solid electrolyte membrane in this application embodiment can be from 0.1 MPa to 50 MPa, and optionally from 0.1 MPa to 10 MPa. For example, the tensile strength of the solid electrolyte membrane can be 0.1 MPa, 0.2 MPa, 0.4 MPa, 0.6 MPa, 0.8 MPa, or 10 MPa, etc. The solid electrolyte membrane has high tensile strength and good mechanical properties.

[0096] In this embodiment, the solid electrolyte particles are bonded together by a non-fibrous thermoplastic polymer. The non-fibrous thermoplastic polymer coats at least a portion of the surface of the solid electrolyte particles; that is, when the non-fibrous thermoplastic polymer coats a portion of the surface of the solid electrolyte particles, it can coat the entire surface of the solid electrolyte particles excluding that portion. Therefore, the ionic conductivity of the solid electrolyte membrane in this embodiment can be 0.1 mS / cm to 100 mS / cm, optionally 0.5 mS / cm to 10 mS / cm. Exemplarily, the ionic conductivity of the solid electrolyte membrane can be 0.5 mS / cm, 1 mS / cm, 2 mS / cm, 4 mS / cm, 6 mS / cm, 8 mS / cm, or 10 mS / cm, etc. The solid electrolyte membrane has a high ionic conductivity, which is beneficial for Li... + The transmission effect is relatively good.

[0097] The solid electrolyte membrane provided in this application embodiment has a non-fibrous thermoplastic polymer forming an effective bond between multiple solid electrolyte particles. Because the solid electrolyte particles are more tightly bonded, the mechanical properties of the solid electrolyte membrane, such as tensile strength, can be improved. Furthermore, since at least some of the solid electrolyte particles do not have non-fibrous thermoplastic polymer on part of their surface, the ionic conductivity of the solid electrolyte membrane remains high. While taking into account both the tensile strength and ionic conductivity of the solid electrolyte membrane, it can also effectively improve the problem of the solid electrolyte membrane being pierced by negative electrode dendrites. Therefore, the solid electrolyte membrane has excellent overall performance.

[0098] In some embodiments, the solid electrolyte membrane further includes a fibrous thermoplastic polymer that extends throughout the solid electrolyte membrane and is wrapped around the surface of at least one solid electrolyte particle; and / or, the fibrous thermoplastic polymer forms a network structure in the solid electrolyte membrane.

[0099] The network structure of the aforementioned fibrous thermoplastic polymer can be used to wrap and support multiple solid electrolyte particles, and the fibrous thermoplastic polymer can be used as a binder to achieve bonding between multiple solid electrolyte particles.

[0100] In practical applications, fibrous thermoplastic polymers can include polytetrafluoroethylene (PTFE). The network-like skeleton structure formed by PTFE fibers can effectively entangle and support multiple solid electrolyte particles, achieving bonding between them.

[0101] In practical applications, the total mass percentage of the non-fibrous thermoplastic polymer and the fibrous thermoplastic polymer in the solid electrolyte membrane is 0.1 wt% to 20 wt%, optionally 0.5 wt% to 10 wt%. For example, the total mass percentage of the non-fibrous thermoplastic polymer and the fibrous thermoplastic polymer in the solid electrolyte membrane can be 0.5 wt%, 1 wt%, 2 wt%, 4 wt%, 6 wt%, 8 wt%, or 10 wt%, etc. This precise total mass allows for effective bonding of multiple solid electrolyte particles while ensuring a high ionic conductivity of the solid electrolyte membrane.

[0102] As an example, the mass ratio of multiple solid electrolyte particles, non-fibrous thermoplastic polymer, and fibrous thermoplastic polymer can be 95–99:0.5–3:0.5–3, or optionally 95–98:1–3:1–2. For example, the mass ratio of multiple solid electrolyte particles, non-fibrous thermoplastic polymer, and fibrous thermoplastic polymer can be 95:2.5:2.5, 96:2:2, 97:1.5:1.5, 98:1:1, 95:3:2, or 97:2:1, etc. By designing the mass ratio of multiple solid electrolyte particles, non-fibrous thermoplastic polymer, and fibrous thermoplastic polymer, effective bonding of multiple solid electrolyte particles can be achieved without affecting the ionic conductivity of the solid electrolyte particles.

[0103] As an example, the mass ratio of non-fibrous thermoplastic polymers in the solid electrolyte membrane and the mass ratio of fibrous thermoplastic polymers in the solid electrolyte membrane can be any ratio.

[0104] Further, the fibrous thermoplastic polymer accounts for 0.01% to 49.9% of the total mass of the non-fibrous thermoplastic polymer and the fibrous thermoplastic polymer, optionally 10% to 49.9%. For example, the fibrous thermoplastic polymer accounts for 10%, 15%, 20%, 25%, 30%, or 49.9% of the total mass of the non-fibrous thermoplastic polymer and the fibrous thermoplastic polymer, etc. Therefore, the higher proportion of non-fibrous thermoplastic polymer compared to fibrous thermoplastic polymer allows for better bonding of multiple solid electrolyte particles without affecting the ionic conductivity of the solid electrolyte particles.

[0105] By using non-fibrous thermoplastic polymers and fibrous thermoplastic polymers to act as a binder between multiple solid electrolyte particles, the mechanical properties of the solid electrolyte membrane, such as tensile strength, are significantly improved without affecting the ionic conductivity of the solid electrolyte membrane, thereby greatly enhancing the overall performance of the solid electrolyte membrane.

[0106] In some embodiments, the thickness of the solid electrolyte membrane is less than or equal to 200 μm, optionally between 20 μm and 200 μm. For example, the thickness of the solid electrolyte membrane can be 20 μm, 50 μm, 100 μm, 130 μm, 180 μm, or 200 μm, etc.

[0107] By setting the thickness of the solid electrolyte membrane to be relatively thin, the battery using this solid electrolyte membrane can achieve high energy density, good cycle stability, and good overall performance.

[0108] Preparation method of solid electrolyte membrane

[0109] Secondly, embodiments of this application provide a method for preparing a solid electrolyte membrane, wherein the solid electrolyte membrane comprises a non-fibrous thermoplastic polymer and a plurality of solid electrolyte particles.

[0110] The fabrication process of the solid electrolyte membrane in this embodiment is shown in Figure 3, and may include the following steps:

[0111] S1. A mixture is obtained by mixing a non-fibrous thermoplastic polymer and multiple solid electrolyte particles;

[0112] S2. The mixture is subjected to at least one first calendering treatment at a temperature higher than the melting point of the non-fibrous thermoplastic polymer, followed by a cooling treatment to obtain a solid electrolyte membrane.

[0113] In the preparation method of the solid electrolyte membrane in the embodiments of this application, the solid electrolyte membrane is the solid electrolyte membrane 1 of the above embodiments.

[0114] The solid electrolyte membrane preparation method provided in this application involves molten non-fibrous thermoplastic polymer at a temperature above its melting point. The molten non-fibrous thermoplastic polymer has strong adhesive properties, initially bonding itself to a portion of the surface of multiple solid electrolyte particles. After cooling, the non-fibrous thermoplastic polymer rapidly solidifies, effectively bonding together with the multiple solid electrolyte particles to form a membrane. This enhances the tensile strength and other mechanical properties of the solid electrolyte membrane, making it less prone to cracking or breakage during preparation. Furthermore, because the non-fibrous thermoplastic polymer tightly bonds the multiple solid electrolyte particles together, the solid electrolyte membrane has high density, making it difficult for lithium dendrites generated at the negative electrode to pierce the membrane. In addition, the multiple solid electrolyte particles still have surfaces not covered by the non-fibrous thermoplastic polymer, ensuring that the ionic conductivity of the solid electrolyte membrane remains high. This improves the overall performance of the solid electrolyte membrane and facilitates continuous production and large-scale rapid mass production of solid electrolyte membranes.

[0115] [Step S1]

[0116] In step S1, the non-fibrous thermoplastic polymer and multiple solid electrolyte particles can be added to a container and stirred thoroughly to obtain the mixture.

[0117] It should be noted that the solid electrolyte particles and non-fibrous thermoplastic polymer in step S1 can be referred to the above embodiments, and will not be repeated here.

[0118] [Step S2]

[0119] There are many types of non-fibrous thermoplastic polymers, each with its own melting point. Therefore, simply selecting a temperature higher than the melting point of the non-fibrous thermoplastic polymer will allow it to reach a molten state. 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 thermoplastic polymer, the first calendering temperature can be set higher than 155°C, for example, 160°C. If both PC and PA are selected as the non-fibrous thermoplastic polymers, the first calendering temperature can be set higher than 250°C, for example, 260°C. No specific limitations are made here.

[0120] The first calendering process in step S2 may include any one of flat plate hot pressing, hot roll pressing, etc.

[0121] Taking the first 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, 60 MPa, 70 MPa, or 80 MPa, etc. The solid electrolyte membrane produced under this pressure has good surface flatness.

[0122] The cooling temperature in step S2 can be room temperature, for example, around 25°C.

[0123] In some embodiments, the fabrication process of the solid electrolyte membrane according to this application is shown in Figure 4, and may include the following steps:

[0124] S1. A mixture is obtained by mixing a non-fibrous thermoplastic polymer and multiple solid electrolyte particles;

[0125] S3. The mixture is subjected to at least one second calendering treatment at a temperature lower than the melting point of the non-fibrous thermoplastic polymer to obtain an initial solid electrolyte membrane with a thickness of less than or equal to 200 μm;

[0126] S4. The initial solid electrolyte membrane is subjected to at least one first calendering treatment at a temperature higher than the melting point of the non-fibrous thermoplastic polymer, followed by a cooling treatment to obtain a solid electrolyte membrane.

[0127] The solid electrolyte membrane preparation method provided in this application embodiment makes the solid electrolyte membrane thinner, resulting in a solid battery with higher energy density, better cycle stability, and better performance.

[0128] [Step S3]

[0129] Because the non-fibrous thermoplastic polymer binds multiple solid electrolyte particles together when it forms a molten state, it makes it difficult to thin the solid electrolyte membrane. Therefore, a thinning process is performed first, and then the non-fibrous thermoplastic polymer is molten.

[0130] The initial solid electrolyte membrane thickness can optionally be less than or equal to 100 μm. For example, the initial solid electrolyte membrane thickness can be 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, or 100 μm, etc. Thus, the initial solid electrolyte membrane is very thin, resulting in a very thin final solid electrolyte membrane.

[0131] The second calendering process in step S3 can be performed once or multiple times. The second calendering process can include any one of the following: hot pressing on a flat plate, hot rolling, etc.

[0132] Taking the second calendering process as an example of hot rolling of the fibrous blend using a roller press, the hot rolling temperature of the roller press can be 25℃~150℃, optionally 50℃~150℃. For example, the hot rolling temperature of the roller press can be 50℃, 70℃, 90℃, 100℃, 120℃, or 150℃, etc.; the rotation speed of the roller press can be 1rpm~50rpm, optionally 1rpm~20rpm. For example, the rotation speed of the roller press can be 1rpm, 5rpm, or 10rpm. The rolling mill can have pressures ranging from 20 rpm, 30 rpm, 40 rpm, or 50 rpm, etc.; the horizontal rolling pressure of the rolling mill can be from 1 t to 80 t, optionally from 10 t to 80 t. For example, the horizontal rolling pressure of the rolling mill can be 10 t, 30 t, 50 t, 70 t, or 80 t, etc.; the vertical rolling pressure of the rolling mill can be from 1 t to 80 t, optionally from 10 t to 80 t. For example, the vertical rolling pressure of the rolling mill can be 10 t, 30 t, 50 t, 70 t, or 80 t, etc. This allows for the formation of a relatively thin initial solid electrolyte film with good flatness, and also enables the subsequent formation of a thinner solid electrolyte film.

[0133] In some embodiments, the solid electrolyte membrane comprises a non-fibrous thermoplastic polymer, a fibrous thermoplastic polymer, and a plurality of solid electrolyte particles.

[0134] The fabrication process of the solid electrolyte membrane in this embodiment is shown in Figure 5, and may include the following steps:

[0135] S10. Mix the non-fibrous thermoplastic polymer, the fibrous thermoplastic polymer and multiple solid electrolyte particles to obtain a mixture;

[0136] S20. The mixture is subjected to fiberization treatment to obtain a fiberized mixture;

[0137] S30. The fibrous mixture is subjected to at least one first calendering treatment at a temperature higher than that of the non-fibrous thermoplastic polymer and lower than that of the fibrous thermoplastic polymer, followed by a cooling treatment to obtain a solid electrolyte membrane.

[0138] The solid electrolyte membrane preparation method provided in this application first involves fiberizing a thermoplastic polymer into fibrous filaments. These filaments are wound around the surface of at least one solid electrolyte particle and penetrate the solid electrolyte membrane, bonding multiple solid electrolyte particles together. However, since the filaments cannot wrap around the surface of the solid electrolyte particles over a large area, a non-fibrous thermoplastic polymer is then melted at a temperature higher than the melting point of the non-fibrous thermoplastic polymer but lower than the melting point of the fibrous thermoplastic polymer. The molten non-fibrous thermoplastic polymer bonds itself to a portion of the surface of the multiple solid electrolyte particles. After cooling, the non-fibrous... The rapid solidification of the non-fibrous thermoplastic polymer allows for effective bonding with more surfaces of the multiple solid electrolyte particles, thereby enhancing the tensile strength and other mechanical properties of the solid electrolyte membrane. This makes it less prone to cracking or breakage during the preparation process. Furthermore, because the non-fibrous thermoplastic polymer tightly bonds the multiple solid electrolyte particles together, it is difficult for negative electrode dendrites to pierce the solid electrolyte membrane. In addition, many surfaces of the multiple solid electrolyte particles are still not coated with the non-fibrous thermoplastic polymer, which ensures the ionic conductivity of the solid electrolyte membrane, improves the overall performance of the solid electrolyte membrane, and facilitates the continuous production and large-scale rapid mass production of solid electrolyte membranes.

[0139] [Step S10]

[0140] As an example, step S10 may include:

[0141] S101. A non-fibrous thermoplastic polymer, a fibrous thermoplastic polymer, and multiple solid electrolyte particles are mixed simultaneously to obtain a mixture.

[0142] It's simple and easy to operate by mixing all the ingredients at the same time.

[0143] As another example, step S10 may include:

[0144] S102. Mix the non-fibrous thermoplastic polymer and multiple solid electrolyte particles to obtain an initial mixed material;

[0145] S103. Add the fibrous thermoplastic polymer to the initial mixed material and mix to obtain a mixture.

[0146] Fiberized thermoplastic polymers have large particles and a certain degree of viscosity. If added at the beginning, they may cause the solid electrolyte particles to agglomerate, making it difficult to mix evenly. Non-fiberized thermoplastic polymers, on the other hand, are not viscous. Therefore, mixing the solid electrolyte particles and non-fiberized thermoplastic polymers evenly first, and then mixing them with the fiberized thermoplastic polymers, results in a more uniform mixture.

[0147] [Step S20]

[0148] In applications, fiberization equipment can be used to fiberize the mixture, processing the thermoplastic polymer into fibrous filaments. The network-like skeleton constructed from these filaments can be used to wrap and support solid electrolyte powder particles, thereby binding multiple solid electrolyte particles together. Fiberization equipment may include high-intensity mixers, high-speed shear mills, and high-speed ball mills.

[0149] 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 thermoplastic polymers.

[0150] 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 thermoplastic polymer can be fully fibroinated.

[0151] [Step S30]

[0152] Fibrous thermoplastic polymers also possess the characteristic of melting in a molten state when heated to a temperature above their melting point, and then rapidly solidifying upon cooling. Therefore, when the first calendering temperature is higher than that of the fibrous thermoplastic polymer, the polymer melts, its fibrous network structure breaks down, and the adhesive properties cannot be achieved using the fibrous structure. Thus, the first calendering temperature is set to be higher than the melting point of the non-fibrous thermoplastic polymer but lower than the melting point of the fibrous thermoplastic polymer.

[0153] Taking PTFE as an example, its melting point is generally 327℃, while the melting points of PC, TPA, PE, PP, PS, PMMA, PVC, nylon, PU, ​​PET, and POM are generally lower than 327℃. Therefore, in order to maintain the network structure of PTFE and keep the non-fibrous thermoplastic polymer in a molten state, taking flatbed hot pressing as an example of the first calendering process, the temperature of the flatbed hot pressing can be 0.1℃ to 326℃, optionally 50℃ to 326℃. For example, the temperature of the flatbed hot pressing can be 50℃, 100℃, 200℃, 230℃, 300℃, or 326℃. When flatbed hot pressing is performed at a temperature higher than the melting point of the non-fibrous thermoplastic polymer, the mixture is heated uniformly, which can form a solid electrolyte film with good surface smoothness and good mechanical properties such as tensile strength. At the same time, the flatbed hot pressing temperature is lower than that of the fibrous thermoplastic polymer, so it will not destroy the network structure of the fibrous thermoplastic polymer.

[0154] It should be noted that good surface flatness of the solid electrolyte membrane means that the thickness deviation of different areas of the solid electrolyte membrane is less than or equal to 3μm.

[0155] In some embodiments, the solid electrolyte membrane comprises a non-fibrous thermoplastic polymer, a fibrous thermoplastic polymer, and a plurality of solid electrolyte particles.

[0156] The fabrication process of the solid electrolyte membrane in this embodiment is shown in Figure 6, and may include the following steps:

[0157] S10. Mix multiple solid electrolyte particles, non-fibrous thermoplastic polymer and fibrous thermoplastic polymer to obtain a mixture;

[0158] S20. The mixture is subjected to fiberization treatment to obtain a fiberized mixture;

[0159] S40. The fibrous mixture is subjected to at least one second calendering treatment at a temperature lower than the melting point of the non-fibrous thermoplastic polymer to obtain an initial solid electrolyte membrane with a thickness of less than or equal to 200 μm.

[0160] S50. The initial solid electrolyte membrane is subjected to at least one first calendering treatment at a temperature higher than the melting point of the non-fibrous thermoplastic polymer and lower than the melting point of the fibrous thermoplastic polymer, followed by a cooling treatment to obtain a solid electrolyte membrane.

[0161] [Step S40]

[0162] Step S40 can be set with reference to the second rolling process in step S3, and will not be repeated here.

[0163] [Step S50]

[0164] Step S50 can be set with reference to the first rolling process in step S2, and will not be repeated here.

[0165] The solid electrolyte membrane preparation method provided in this application embodiment makes the solid electrolyte membrane thinner, resulting in higher energy density, better cycle performance, and better overall performance of the battery using the solid electrolyte membrane.

[0166] Electrolytic cell

[0167] Thirdly, embodiments of this application provide an electrical battery cell. The electrical battery cell provided in this application includes a positive electrode, a negative electrode, and a solid electrolyte membrane, with the solid electrolyte membrane stacked between the positive and negative electrodes. The solid electrolyte membrane is solid electrolyte membrane 1 as shown in Figures 1 and 2 of the embodiments of this application above.

[0168] Since the battery cell of this application embodiment contains the solid electrolyte membrane 1 of Figures 1 and 2 of the above-mentioned embodiments of this application, the cycle performance of the battery cell of this application embodiment is significantly improved, and the safety and other electrochemical performance of the battery cell are also significantly improved.

[0169] The battery cell in this application refers to the basic unit for realizing 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 mixed. Mixed connection means that multiple battery cells are connected in both series and parallel configurations. Multiple battery cells can be directly connected in series, parallel, or mixed together; alternatively, multiple battery cells can first be connected in series, parallel, or mixed to form a battery module, and then multiple battery modules can be connected in series, parallel, or mixed 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.

[0170] 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 a solid-state battery cell with a square structure as shown in Figure 7.

[0171] Figure 8 is an exploded view of an electric battery cell 30 provided in some embodiments of this application. Referring to Figure 8, the outer packaging of the electric 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, and the solid electrolyte membrane 1 of Figures 1 and 2 in the embodiments of this application is encapsulated within the receiving cavity.

[0172] Figure 9 is a schematic diagram of a solid electrolyte membrane 1 stacked between the positive electrode 2 and the negative electrode 3 according to some embodiments of this application.

[0173] In practical applications, the positive electrode 2 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.

[0174] As in the example, the positive electrode 2 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.

[0175] The positive electrode active material layer in positive electrode 2 may contain components such as positive electrode active material, conductive agent, and binder. The types and amounts of these components are not specifically limited and can be determined according to actual needs.

[0176] 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.

[0177] 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.

[0178] 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.

[0179] In addition, the positive electrode 2 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.

[0180] In practical applications, the negative electrode 3 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.

[0181] As an example, negative electrode 3 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.

[0182] The negative electrode active material layer in negative electrode 3 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.

[0183] As an example, the negative electrode active material may include one or more combinations of carbon-based materials and silicon-based materials.

[0184] 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).

[0185] 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.

[0186] In addition, the negative electrode 3 can also be a lithium indium alloy negative electrode or a lithium metal negative electrode.

[0187] The battery cell provided in this application uses a solid electrolyte membrane with good mechanical properties such as tensile strength, which reduces the risk of short-circuit failure, and also has good electrochemical performance and high safety.

[0188] Battery

[0189] Fourthly, embodiments of this application provide a battery, which includes an electrical battery cell. The electrical battery cell described in the embodiments of this application is the same as the one described above.

[0190] In some embodiments of this application, battery 40 may be a solid-state battery. Specifically, solid-state batteries may include all-solid-state batteries, semi-solid-state batteries, and quasi-solid-state batteries. Solid-state batteries come in various forms, including but not limited to any one of the following: battery cells, battery modules, and battery packs.

[0191] Figure 10 is an exploded view of a battery 40 provided in some embodiments of this application. Referring to Figure 10, the battery 40 may include a housing 401 and an electric battery cell 30, wherein the electric battery cell 30 is housed within the housing 401. The housing 401 is a component that provides housing space for the electric battery cell 30, and the housing 401 may adopt various structures.

[0192] 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.

[0193] In battery 40, multiple battery cells 30 can be directly connected in series, parallel, or in a hybrid configuration, and then the entire assembly of the multiple battery cells 30 is housed within housing 401. Alternatively, battery 40 can also be in the form of a battery module composed of multiple battery cells 30 first connected in series, parallel, or in a hybrid configuration, and then multiple battery modules are connected in series, parallel, or in a hybrid configuration to form an entire assembly, which is also housed within housing 401. Battery 40 may also include other structures, such as a busbar (not shown in Figure 10), which can be used to realize the electrical connection between multiple battery cells 30.

[0194] The battery provided in this application embodiment uses a single battery cell with good electrochemical performance, thus significantly improving the battery's cycle performance and safety.

[0195] Electrical appliances

[0196] 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.

[0197] 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.

[0198] 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.

[0199] Figure 11 is a structural schematic diagram of a vehicle 50 provided in some embodiments of this application. Referring to Figure 11, a battery 40 is disposed inside the vehicle 50. The battery 40 can be disposed 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.

[0200] As shown in Figure 11, 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 needs of the vehicle 50 during startup, navigation and driving.

[0201] The power device provided in this application embodiment has good safety and long standby and battery life because it uses a battery with good overall performance.

[0202] Energy storage devices

[0203] 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.

[0204] 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.

[0205] The energy storage device provided in this application embodiment has good safety and a long service life because it uses a battery with good overall performance.

[0206] Example

[0207] 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.

[0208] Example A1

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

[0210] The solid electrolyte membrane in this embodiment includes: Li 5.4 PS 4.5 Cl 1.5 And PC, Li 5.4 PS 4.5 Cl 1.5 :PC = 99:1, Li 5.4 PS 4.5 Cl 1.5 The particle size is 0.1 μm.

[0211] The method for preparing the solid electrolyte membrane in this embodiment includes the following steps:

[0212] Step 1: Place Li 5.4 PS 4.5 Cl 1.5 It is mixed with PC to obtain a mixture.

[0213] Step 2: The mixture is hot-pressed on a flat plate at a temperature of 230°C and a pressure of 10 MPa, and then cooled to room temperature to obtain a solid electrolyte membrane.

[0214] Examples A2 to A3

[0215] Examples A2 to A3 respectively provide a solid electrolyte membrane and its preparation method. The solid electrolyte membranes provided in Examples A2 to A3 differ from those provided in Example A1 in that Li... 5.4 PS 4.5 Cl 1.5 Compared to PC, Li 5.4 PS 4.5 Cl 1.5 They differ in at least one of the relevant parameters such as particle size, but are the same in the others.

[0216] The preparation methods of the solid electrolyte membranes provided in Examples A2 to A3 differ from those in Example A1 in that the temperature and pressure of the hot pressing of the plate are controlled differently in step 2 to realize the solid electrolyte membranes provided in each of Examples A2 to A3 respectively. The other steps are the same as those in Example A1.

[0217] Specifically, in step 2 of the solid electrolyte membrane preparation method in Example A2, the mixture is subjected to flat plate hot pressing at a temperature of 235°C and a pressure of 20MPa, and then cooled to room temperature to obtain a solid electrolyte membrane.

[0218] In step 2 of the solid electrolyte membrane preparation method in Example A3, the mixture is subjected to flat plate hot pressing at a temperature of 240°C and a pressure of 30 MPa, and then cooled to room temperature to obtain a solid electrolyte membrane.

[0219] Example A4

[0220] This embodiment A4 provides a solid electrolyte membrane and its preparation method. The solid electrolyte membrane provided in this embodiment A4 has the same relevant parameters as the solid electrolyte membrane provided in embodiment A3.

[0221] The method for preparing the solid electrolyte membrane provided in Example A4 differs from that in Example A3 in that step 3 is added between step 1 and step 2, and step 2 is changed to step 4 to realize the solid electrolyte membrane provided in Example A4. All other steps are the same as those in Example A3.

[0222] Specifically, the solid electrolyte membrane preparation method of Example A4 includes step 3 after step 1 and before step 2: placing the mixture in a roller press and performing multiple hot rolling presses at a speed of 50 rpm, a temperature of 100°C, a horizontal rolling pressure of 80t, and a vertical rolling pressure of 80t to obtain an initial solid electrolyte membrane; step 4: hot pressing the initial solid electrolyte membrane on a flat plate at a temperature of 240°C and a pressure of 30MPa, and then cooling it to room temperature to obtain a solid electrolyte membrane.

[0223] Example A5

[0224] This embodiment A5 provides a solid electrolyte membrane and its preparation method.

[0225] The solid electrolyte membrane in embodiment A5 includes: Li 5.4 PS 4.5 Cl 1.5 , PC and PTFE, Li 5.4 PS 4.5 Cl 1.5 The solid electrolyte membrane contains 80 wt% PC, 16 wt% PC, and 4 wt% PTFE. Li 5.4 PS 4.5 Cl 1.5 The particle size is 0.1 μm.

[0226] The preparation method of the solid electrolyte membrane in Example A5 includes the following steps:

[0227] Step 1: Place Li 5.4 PS 4.5 Cl 1.5 PC and PTFE are mixed to obtain a mixture;

[0228] Step 2: Place the mixture in a high-intensity mixer and perform fiberization treatment at 3000 rpm for 100 minutes to obtain a fiberized mixture;

[0229] Step 3: The fibrous mixture is hot-pressed on a flat plate at a temperature of 240°C and a pressure of 30 MPa, and then cooled to room temperature to obtain a solid electrolyte membrane.

[0230] Examples A6 to A9 each provide a solid electrolyte membrane and a method for preparing the same. The solid electrolyte membranes provided in Examples A6 to A9 differ from the solid electrolyte membrane provided in Example A5 in that Li... 5.4 PS 4.5 Cl 1.5 The mass ratio of PC to PTFE, Li 5.4 PS 4.5 Cl1.5 They differ in at least one of the relevant parameters such as particle size, but are the same in the others.

[0231] The preparation methods of the solid electrolyte membranes provided in Examples A6 to A9 differ from those in Example A5 in that: the fiberization speed and time in step 2 are controlled differently, and the hot pressing temperature and pressure of the plate in step 3 are controlled differently, so as to realize the solid electrolyte membranes provided in each of Examples A6 to A9 respectively. All other steps are the same as those in Example A5.

[0232] Specifically, in step 2 of the solid electrolyte membrane preparation method of Example A6, the initial mixed material is placed in a high-power mixer and subjected to fiberization treatment at a speed of 4000 rpm for 50 min to obtain a fiberized mixture; in step 3, the fiberized mixture is subjected to flat plate hot pressing at a temperature of 240°C and a pressure of 20 MPa, and then cooled to room temperature to obtain a solid electrolyte membrane.

[0233] In step 2 of the solid electrolyte membrane preparation method of Example A7, the initial mixed material is placed in a high-intensity mixer and subjected to fiberization treatment at a speed of 5000 rpm for 100 min to obtain a fiberized mixture; in step 3, the fiberized mixture is subjected to flat plate hot pressing at a temperature of 250°C and a pressure of 10 MPa, and then cooled to room temperature to obtain a solid electrolyte membrane.

[0234] In step 2 of the solid electrolyte membrane preparation method of Example A8, the initial mixed material is placed in a high-intensity mixer and subjected to fiberization treatment at a speed of 6000 rpm for 150 min to obtain a fiberized mixture; in step 3, the fiberized mixture is subjected to flat plate hot pressing at a temperature of 260°C and a pressure of 40 MPa, and then cooled to room temperature to obtain a solid electrolyte membrane.

[0235] In step 2 of the solid electrolyte membrane preparation method of Example A9, the initial mixed material is placed in a high-intensity mixer and subjected to fiberization treatment at a speed of 7000 rpm for 200 min to obtain a fiberized mixture; in step 3, the fiberized mixture is subjected to flat plate hot pressing at a temperature of 270°C and a pressure of 50 MPa, and then cooled to room temperature to obtain a solid electrolyte membrane.

[0236] Example A10:

[0237] This embodiment A10 provides a solid electrolyte membrane and its preparation method. The solid electrolyte membrane provided in this embodiment A10 has the same relevant parameters as the solid electrolyte membrane provided in embodiment A5.

[0238] The method for preparing the solid electrolyte membrane provided in Example A10 differs from that in Example A5 in that step 4 is added between step 2 and step 3, and step 3 is changed to step 5 to realize the solid electrolyte membrane provided in Example A10. All other steps are the same as those in Example A5.

[0239] Specifically, the solid electrolyte membrane preparation method of Example A10 includes step 4 after step 2 and before step 3: placing the fibrous mixture in a roller press and performing multiple hot rolling presses at a speed of 50 rpm, a temperature of 100°C, a horizontal calendering pressure of 80t, and a vertical calendering pressure of 80t to obtain an initial solid electrolyte membrane; step 5: hot pressing the initial solid electrolyte membrane on a flat plate at a temperature of 240°C and a pressure of 30MPa, and then cooling it to room temperature to obtain a solid electrolyte membrane.

[0240] Comparative Example A1

[0241] Comparative Example A1 provides a solid electrolyte membrane and its preparation method.

[0242] The solid electrolyte membrane of Comparative Example A1 includes: Li 5.4 PS 4.5 Cl 1.5 And PTFE, Li 5.4 PS 4.5 Cl 1.5 The solid electrolyte membrane contains 80 wt% PTFE and 20 wt% Li. 5.4 PS 4.5 Cl 1.5 The particle size is 0.1 μm.

[0243] The preparation method of the solid electrolyte membrane in Comparative Example A1 includes the following steps:

[0244] Step 1: Place Li 5.4 PS 4.5 Cl 1.5 It is mixed with PTFE to obtain a mixture.

[0245] Step 2: Place the mixture in a high-intensity mixer and perform fiberization treatment at 3000 rpm for 100 minutes to obtain a fiberized mixture;

[0246] Step 3: The fibrous mixture is hot-pressed on a flat plate at a temperature of 240°C and a pressure of 30 MPa, and then cooled to room temperature to obtain a solid electrolyte membrane.

[0247] Comparative Example A2

[0248] The solid electrolyte membrane provided in Comparative Example A2 differs from the solid electrolyte membrane in Comparative Example A1 in that: Li 5.4 PS 4.5 Cl 1.5 The particle size is 200 μm, and everything else is the same.

[0249] Comparative Example A3

[0250] The preparation method of the solid electrolyte membrane provided by Comparative Example A3 differs from that of Comparative Example A1 in that: a step 4 is added between step 2 and step 3, and step 3 is changed to step 5 to realize the solid electrolyte membrane provided by Comparative Example A3. All other steps are the same as those of Comparative Example A1.

[0251] The relevant characteristic parameters of the solid electrolyte membranes provided in Examples A1 to A10 and Comparative Examples A1 to A3 are shown in Table 1 below.

[0252] 2. Characterization and related performance tests of the solid electrolyte membranes in each embodiment and comparative example:

[0253] The relevant characteristic parameters of the solid electrolyte membranes provided in Examples A1 to A10 and Comparative Examples A1 to A3 above were then used to perform the relevant characteristic detections in Table 1 below according to the following methods. The detection results are shown in Table 1.

[0254] The detection methods for relevant characteristics of solid electrolyte membranes in Table 1 are as follows:

[0255] (1). Dv50 test method: The test shall be carried out in accordance with the method and procedure in GB / T16418.

[0256] (2) Method for detecting the mass percentage of each component in a solid electrolyte: 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.

[0257] Table 1

[0258] 3. In order to verify the progressiveness of the embodiments of this application, the samples prepared in Examples A1 to A10 and Comparative Examples A1 to A3 are tested below.

[0259] The testing method is as follows:

[0260] (1). Tensile strength test:

[0261] The tensile strength of a high-strength solid electrolyte membrane was tested using a universal tensile testing machine at room temperature.

[0262] The specific steps are as follows: use a punching machine to punch out a 15mm×70mm sample, fix the sample on the test fixture of the universal tensile testing machine, and conduct the test at a tensile speed of 5mm / min and a standard distance S0 between the two fixtures of the tensile testing machine of 50mm.

[0263] Record the tensile strength and displacement, and select the maximum tensile strength value in the displacement curve as the required tensile strength.

[0264] (2). Thickness test:

[0265] The thickness of the high-strength solid electrolyte membrane was measured using a micrometer.

[0266] (3). Ionic conductivity test:

[0267] The ionic conductivity of a high-strength solid electrolyte membrane was tested using an AC impedance analyzer at room temperature.

[0268] The specific steps are as follows: the impedance of the high-strength solid electrolyte membrane is tested under an AC impedance of 107Hz at a constant temperature of 25±0.1℃, and the ionic conductivity is calculated in combination with the measured thickness of the high-strength solid electrolyte membrane.

[0269] The samples prepared in Examples A1 to A10 and Comparative Examples A1 to A3 were tested, and the data on tensile strength, ionic conductivity and thickness were obtained, as shown in Table 2 below.

[0270] Table 2

[0271] First, compared with Comparative Examples A1 to A3 in Table 1, Examples A1 to A10 have higher tensile strength, and although the ionic conductivity is slightly reduced, the difference is not significant. The thickness can be made thinner.

[0272] Secondly, comparing Examples A1 to A3 in Table 1, it can be seen that as the content of PC in the solid electrolyte membrane increases, the tensile strength of the solid electrolyte membrane increases, the ionic conductivity decreases slightly but not by much, and the thickness can be made thinner.

[0273] Comparing Examples A3 and A4 in Table 1, it can be seen that the thickness of the solid electrolyte membrane obtained after the thinning process can be thinner.

[0274] Comparing Examples A4 to A7 in Table 1, it can be seen that replacing part of the PC with PTFE results in a lower tensile strength and a slightly higher ionic conductivity of the solid electrolyte membrane, but the difference is not significant.

[0275] Comparing Examples A5, A8, and A9 in Table 1, it can be seen that as Li5.4 PS 4.5 Cl 1.5 As the particle size increases, the tensile strength of the solid electrolyte membrane decreases slightly but not by much, while the ionic conductivity increases slightly but not by much.

[0276] Comparing Examples A10 and A5 in Table 1, it can be seen that the thickness of the solid electrolyte membrane obtained after the thinning process can be thinner.

[0277] 4. Solid-state battery examples

[0278] Examples B1 to B10 and Comparative Examples B1 to B3

[0279] Examples B1 to B10 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 solid electrolyte film, and a negative electrode sheet.

[0280] The solid-state battery cells in Examples B1 to B10 and Comparative Examples B1 to B3 are assembled as follows:

[0281] (1). Preparation of the positive electrode film:

[0282] 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 weight 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 obtain a positive electrode film.

[0283] (2). Preparation of negative electrode sheet:

[0284] Lithium-indium alloy is used as the negative electrode.

[0285] (3) Assembly of solid-state battery cells:

[0286] The prepared positive electrode film is placed in a mold, and the high-strength solid electrolyte film and lithium indium alloy are stacked in sequence. Then, it is cold-pressed under a pressure of 200 MPa to obtain a solid battery cell.

[0287] 5. Electrochemical performance testing of solid-state battery cells in each embodiment:

[0288] The solid-state battery cells provided in Examples B1 to B10 and Comparative Examples B1 to B3 were subjected to the relevant electrochemical performance tests shown in Table 3 below, and the test results are shown in Table 3.

[0289] The relevant performance testing methods for solid-state battery cells are listed in Table 3.

[0290] (1). Charge-discharge cycle performance test of solid-state battery cells:

[0291] The test was conducted using a prototype battery mold at a temperature of 45°C.

[0292] 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, and record the capacity retention rate, number of charge-discharge cycles, and specific capacity of each solid-state battery cell.

[0293] The solid-state battery cells assembled from the samples prepared in Examples B1 to B10 and Comparative Examples B1 to B3 were tested to obtain data on the capacity retention rate at 0.2C, the number of cycles at 80% capacity retention rate at 0.2C, and the specific capacity, as shown in Table 3 below.

[0294] Table 3

[0295] First, based on the data in Tables 1 to 3, and comparing Examples B1 to B10 in Table 3 with Comparative Examples B1 to B3, the solid-state battery can cycle approximately 200 to 400 times at 0.2C at 45°C, with a capacity retention rate of 70% to 90% and a specific capacity of 180 mAh / g to 200 mAh / g. This means that the solid-state battery has a high 0.2C capacity retention rate and a high number of cycles when the 0.2C capacity retention rate is 80%. Although the specific capacity is slightly lower, the cycle stability of the solid-state battery cells is better.

[0296] Secondly, comparing Examples B1 to B3 in Table 3, it can be seen that as the PC content increases, the number of cycles of the solid-state battery cell at 80% capacity retention at 0.2C increases slightly, and the specific capacity decreases slightly, but the difference is not significant.

[0297] Comparing Examples B4 to B7 in Table 1, it can be seen that by replacing part of the PC with PTFE, the number of cycles of the solid-state battery cell at 0.2C capacity retention of 80% decreases slightly, and the specific capacity increases slightly, but the difference is not significant.

[0298] Comparing Examples B5, B8, and B9 in Table 1, it can be seen that as Li 5.4 PS 4.5 Cl 1.5With increased particle size, the number of cycles of solid-state battery cells at 0.2C with 80% capacity retention decreases slightly, while the specific capacity increases slightly, but the difference is not significant.

[0299] In contrast, the solid-state battery cell made from the solid electrolyte membrane without added PC provided by Comparative Example B1 experienced a short circuit failure after only 150 cycles, indicating poor performance.

[0300] Comparative example B2 provided without PC and Li 5.4 PS 4.5 Cl 1.5 Solid-state battery cells made with solid electrolyte membranes with larger particle sizes experienced short-circuit failure after only 140 cycles, indicating poor performance.

[0301] The solid-state battery cell provided by Comparative Example B3, which was made without PC and with a thinned solid electrolyte membrane, failed to short-circuit after only 150 cycles, indicating poor performance.

[0302] 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 solid electrolyte membrane, characterized in that, It includes at least a non-fibrous thermoplastic polymer and a plurality of solid electrolyte particles, wherein each of the solid electrolyte particles is bonded together by the non-fibrous thermoplastic polymer; Wherein, the tensile strength of the solid electrolyte membrane is 0.1 MPa to 50 MPa; and / or, The ionic conductivity of the solid electrolyte membrane is 0.1 mS / cm to 100 mS / cm.

2. The solid electrolyte membrane according to claim 1, characterized in that, The non-fibrous thermoplastic polymer in the solid electrolyte membrane has a mass percentage content of 0.1 wt% to 20 wt%; and / or, The total mass ratio of the solid electrolyte particles to the non-fibrous thermoplastic polymer is 95-99:1-5.

3. The solid electrolyte membrane according to claim 1 or 2, characterized in that, The solid electrolyte membrane further includes a fibrous thermoplastic polymer, which extends throughout the solid electrolyte membrane. The fibrous thermoplastic polymer is wound around the surface of at least one of the solid electrolyte particles; and / or, The fibrous thermoplastic polymer forms a network structure in the solid electrolyte membrane.

4. The solid electrolyte membrane according to claim 3, characterized in that, The total mass percentage of the non-fibrous thermoplastic polymer and the fibrous thermoplastic polymer in the solid electrolyte membrane is 0.1 wt% to 20 wt%.

5. The solid electrolyte membrane according to claim 3 or 4, characterized in that, The fibrous thermoplastic polymer comprises 0.01% to 49% of the total mass of the non-fibrous thermoplastic polymer and the fibrous thermoplastic polymer; and / or, The mass ratio of the total mass of the solid electrolyte particles, the non-fibrous thermoplastic polymer, and the fibrous thermoplastic polymer is 95–99:0.5–3:0.5–3; and / or, The fibrous thermoplastic polymer includes polytetrafluoroethylene.

6. The solid electrolyte membrane according to any one of claims 1 to 5, characterized in that, The non-fibrous thermoplastic polymer includes at least one of polyamide, polyethylene, polypropylene, polystyrene, polymethyl methacrylate, polyvinyl chloride, nylon, polycarbonate, polyurethane, polyethylene terephthalate, and polyoxymethylene.

7. The solid electrolyte membrane according to any one of claims 1 to 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 particle size of the solid electrolyte particles is 0.1 μm to 100 μm; The sulfide solid electrolyte particles include Li 5.4 PS 4.5 Cl 1.5 Li3PS4(LPS), Li 10 GeP2S 12 At least one of (LGPS), Li6PS5Cl (LPSCl), Li6PS5I (LPSI), and Li6PS5Br (LPSBr); The halide solid electrolyte particles include Li3InCl6, Li3YCl6, Li3ScCl6, Li3TaCl6, Li3ZrCl6, and Li3Y. 1-x In x At least one of Cl6 (0≤x≤1), Li3YbCl6, and Li3HoCl6.

8. The solid electrolyte membrane according to any one of claims 1 to 7, characterized in that, The thickness of the solid electrolyte membrane is less than or equal to 200 μm.

9. A method for preparing a solid electrolyte membrane, characterized in that, Includes the following steps: A non-fibrous thermoplastic polymer and multiple solid electrolyte particles are mixed to form a mixture, which is then subjected to at least one first calendering treatment at a temperature higher than the melting point of the non-fibrous thermoplastic polymer, followed by a cooling treatment to obtain the solid electrolyte membrane; wherein the tensile strength of the solid electrolyte membrane is 0.1 MPa to 50 MPa; and / or the ionic conductivity of the solid electrolyte membrane is 0.1 mS / cm to 100 mS / cm.

10. The method for preparing a solid electrolyte membrane according to claim 9, characterized in that, The first calendering process, performed at least once at a temperature above the melting point of the non-fibrous thermoplastic polymer, includes: The mixture is subjected to at least one second calendering treatment at a temperature lower than the melting point of the non-fibrous thermoplastic polymer to obtain an initial solid electrolyte membrane with a thickness of less than or equal to 200 μm. The initial solid electrolyte membrane is subjected to the first calendering process at least once at a temperature higher than the melting point of the non-fibrous thermoplastic polymer.

11. The method for preparing a solid electrolyte membrane according to claim 9, characterized in that, Includes the following steps: The non-fibrous thermoplastic polymer and the plurality of solid electrolyte particles are mixed to obtain an initial mixed material; A fibrous thermoplastic polymer is added to the initial mixed material and mixed to obtain a mixture; The mixture is subjected to a fiberization treatment to obtain a fiberized mixture; wherein the fiberized thermoplastic polymer runs through the solid electrolyte membrane, and the fiberized thermoplastic polymer is wrapped around the surface of at least one of the solid electrolyte particles; and / or, the fiberized thermoplastic polymer forms a network structure in the solid electrolyte membrane; The fibrous mixture is subjected to the first calendering process at least once at a temperature higher than the melting point of the non-fibrous thermoplastic polymer and lower than the melting point of the fibrous thermoplastic polymer, followed by the cooling process, to obtain the solid electrolyte membrane.

12. The method for preparing a solid electrolyte membrane according to claim 11, characterized in that, After the step of obtaining the fibrous mixture and before the cooling treatment, the following steps are also included: The fibrous mixture is subjected to at least one second calendering treatment at a temperature lower than the melting point of the non-fibrous thermoplastic polymer to obtain an initial solid electrolyte membrane with a thickness of less than or equal to 200 μm. The initial solid electrolyte membrane is subjected to the first calendering process at least once at a temperature higher than the melting point of the non-fibrous thermoplastic polymer and lower than the melting point of the fibrous thermoplastic polymer.

13. A single battery cell, characterized in that, This includes solid electrolyte membranes according to any one of claims 1 to 8 or solid electrolyte membranes prepared by the preparation method according to any one of claims 9 to 12.

14. A battery, characterized in that, Includes the battery cell according to claim 13.

15. An electrical appliance, characterized in that, Includes the battery according to claim 14.

16. An energy storage device, characterized in that, Includes the battery according to claim 14.

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