Electrode assemblies, battery cells, batteries, and power consumption devices

Abstract

Provided are an electrode assembly, a battery cell, a battery, and an electric power consumption device. The electrode assembly includes a positive electrode sheet, a negative electrode sheet, a separator, and an organic coating. The separator is provided between the positive electrode sheet and the negative electrode sheet. The organic coating is provided on a side of the positive electrode sheet facing the separator and / or on one side of the separator. The organic coating includes organic particles that react with dendrites containing a single metal.

Description

[Technical Field]

[0001] Cross-reference of related applications This application claims priority to Chinese Patent Application No. 202310070849.5, filed on 17 January 2023, titled "Electrode Assembly, Battery Cell, Battery and Power Consumption Device," the entirety of which is incorporated herein by reference.

[0002] This application relates to the battery technology field, and more specifically to electrode assemblies, battery cells, batteries, and power consumption devices. [Background technology]

[0003] With the increasing scarcity of conventional energy sources, new energy sources are gradually becoming an important type of energy in various industries. Batteries are a prime example of this new energy source. With rapid technological advancements, batteries are widely used in various industries, such as power tools, electric vehicles, and energy storage equipment. To meet the growing needs of these industries, the demands on battery performance, such as safety features, are also increasing. Therefore, there is a strong need to improve the safety performance of batteries to meet the growing needs of various industries. [Overview of the project]

[0004] This application provides an electrode assembly, a battery cell, a battery, and a power consumption device that can improve the safety performance of a battery.

[0005] A first aspect of this application provides an electrode assembly comprising a positive electrode sheet, a negative electrode sheet, a separator interposed between the positive electrode sheet and the negative electrode sheet, and an organic coating provided on the side of the positive electrode sheet facing the separator and / or on one side of the separator, the coating containing organic particles that react with dendrites made of a single metal.

[0006] In the electrode assembly according to the present application, the organic coating is provided on the side facing the separator of the positive electrode sheet and / or on one side of the separator, and contains organic particles that react with dendrites composed of a single metal. When dendrites containing a single metal are generated inside the battery during use, once these dendrites grow to a certain extent, they will contact and react with the organic particles in the organic coating to generate gas. As a result, the probability of short circuit inside the battery due to the electrical connection between the positive electrode sheet and the negative electrode sheet is reduced, and the pressure inside the battery rises to break the explosion-proof valve of the battery to release the pressure. Therefore, the risk of the battery exploding is reduced, and the safety performance of the battery can be improved.

[0007] According to any of the above embodiments of the first aspect of the present application, the organic particles contain a reactive group that reacts with dendrites containing a single sodium metal. The reactive group can be advantageous for a rapid reaction with dendrites containing a single sodium metal, and further effectively reduces the occurrence of internal short circuits in the battery and the risk of battery explosion caused by the electrical connection between the positive electrode and the negative electrode by dendrites, improving the safety performance of the battery.

[0008] According to any of the above embodiments of the first aspect of the present application, the reactive group contains one or more of a carboxyl group, a hydroxyl group, an amino group, a thiol group, a phenolic hydroxyl group, and a biphenyl group. The above reactive group is likely to react with dendrites containing a single sodium metal, and can further effectively reduce the electrical connection between the positive electrode and the negative electrode by the above dendrites, further improving the safety performance of the battery.

[0009] According to any of the above embodiments of the first aspect of the present application, the material of the organic particles contains one or more of benzoic acid, benzophenone, indole acetic acid, phenol, and biphenyl.

[0010] According to any of the above embodiments of the first aspect of this application, the organic coating includes one or more of the following: a mesh-like organic coating, a dot-like organic coating, and a stripe-like organic coating. The above coating can contribute to improving the safety performance and cycle performance of the battery.

[0011] According to any of the above embodiments of the first aspect of this application, the organic coating is provided on the side of the positive electrode sheet facing the separator. By providing the organic coating on the side of the positive electrode sheet facing the separator, the occurrence of internal short circuits in the battery caused by the electrical connection between the positive and negative electrodes by dendrites can be effectively reduced, and the safety performance of the battery can be further improved.

[0012] According to any of the above embodiments of the first aspect of this application, the thickness H1 of the organic coating is 2 μm to 10 μm. Setting the thickness of the organic coating within this range further improves the safety performance of the battery, and by providing an appropriate thickness to the organic coating, more active material can be filled in, contributing to an improvement in the energy density of the battery.

[0013] According to any of the above embodiments of the first aspect of this application, the separator includes a first base film and a second base film, and the organic coating is provided between the first base film and the second base film. By including the first and second base films in the separator, the mechanical strength of the separator can be increased and dendrites can be prevented from penetrating the separator. Furthermore, by providing the organic coating between the first and second base films, the organic particles in the organic coating react with dendrites that have penetrated the first or second base film, further preventing the dendrites from completely penetrating the separator, thereby further improving the safety performance of the battery.

[0014] According to any of the above embodiments of the first aspect of this application, the thickness of the organic coating is 2 μm to 10 μm. By setting the thickness of the organic coating within this range, the probability of the positive and negative electrodes being electrically connected by dendrites is reduced, thereby improving the safety performance of the battery, and the filling space for the active material is increased, thereby improving the energy density of the battery.

[0015] According to any of the above embodiments of the first aspect of this application, the thickness of the first base film is 5 μm to 20 μm.

[0016] According to any of the above embodiments of the first aspect of this application, the thickness of the second base film is 5 μm to 20 μm.

[0017] According to any of the above embodiments of the first aspect of this application, the surface density of the organic coating is 1.5 g / m². 2 ~4.0g / m 2 Therefore, by setting the surface density of the organic coating within the above range, the organic coating can effectively reduce the electrical connection between the positive and negative electrodes due to dendrites.

[0018] According to any of the above embodiments of the first aspect of this application, the organic coating further comprises an adhesive, and the mass ratio of the adhesive to the organic particles is (1-5):(10-90) based on the mass of the organic coating. The addition of the adhesive increases the viscosity of the organic coating, further strengthens the bonding force between the organic coating and the positive electrode sheet, negative electrode sheet, and separator, and reduces peeling of the organic coating. Furthermore, when the mass ratio of the adhesive to the organic particles satisfies the above relationship, the organic coating can react with dendrites to reduce them while maintaining good viscosity, thereby further improving the safety performance of the battery.

[0019] According to any of the above embodiments of the first aspect of this application, the mass content of the adhesive in the organic coating is 1% to 5%.

[0020] According to any of the above embodiments of the first aspect of this application, the mass content of organic particles in the organic coating is 80% to 90%. By setting the mass content of organic particles in the organic coating to the above range, the organic coating reacts with more elemental metals, further reducing the possibility of the positive and negative electrodes being electrically connected by dendrites, thereby more effectively improving the safety performance of the battery.

[0021] A second aspect of this application provides a battery cell including an electrode assembly according to the first aspect of this application.

[0022] A third aspect of this application provides a battery including a battery cell according to a second aspect of this application.

[0023] A fourth aspect of this application provides a power consumption device including a battery according to a third aspect of this application.

[0024] The above description is merely an outline of the technical solution of this application. To better understand the technical means of this application, it can be implemented according to the specifications. Furthermore, to make the above and other objectives, features, and advantages of this application easier to understand, specific embodiments of this application are listed below. [Brief explanation of the drawing]

[0025] Those skilled in the art will find various other advantages and effects apparent by reading the detailed description of the following selectable embodiments. The drawings are for illustrative purposes only and do not limit this application. In all drawings, the same components are denoted by the same reference numerals. The drawings are not necessarily drawn to actual scale. [Figure 1] This is a schematic diagram showing a battery cell according to several embodiments of this application. [Figure 2] Figure 1 is a conceptual diagram of a battery cell in an exploded view. [Figure 3] This is a schematic diagram showing a battery module according to several embodiments of this application. [Figure 4] This is a schematic diagram showing a battery pack according to several embodiments of this application. [Figure 5] Figure 4 is a conceptual exploded view showing the battery pack. [Figure 6] This is a schematic diagram showing a power consumption device according to several embodiments of this application. (Reference numeral explanation)

[0026] 1 Battery pack, 2 Upper housing, 3 Lower housing, 4 Battery module, 5 Battery cell, 51 Housing, 52 Electrode assembly, 53 Cover plate. [Modes for carrying out the invention]

[0027] The embodiments of the technical solution of this application will be described in detail below with reference to the drawings. The embodiments described below are merely illustrative to more clearly explain the technical solution of this application and are not intended to limit the scope of protection of this application.

[0028] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present application. Terms used herein are solely for the purpose of describing specific embodiments and are not intended to limit this application. The terms “including” and “having,” as well as any variations thereof, contained in the description, claims, and drawings of this application are intended to cover non-exclusive inclusion.

[0029] In the description of the embodiments of this application, technical terms such as “first” and “second” are merely for distinguishing different subjects and should not be understood as indicating or implying relative importance, or implicitly indicating the number, specific order, or hierarchical relationship of the indicated technical features. In the description of the embodiments of this application, “multiple” means two or more unless otherwise clearly and specifically limited.

[0030] The “Examples” as used herein mean that certain features, structures, or properties described in relation to the Examples may be included in at least one Example of this Application. The phrases used in each part of this Specification do not necessarily all refer to the same Example, nor are they mutually exclusive, independent, or alternative Examples. It will be explicitly and implicitly understood by those skilled in the art that the Examples described herein can be combined with other Examples.

[0031] In the description of the embodiments of this application, the term "and / or" merely describes the relationship between the related objects and indicates that three different situations may exist. For example, A and / or B indicates that there may be three cases: A existing alone, A and B existing together, and B existing alone. In this specification, the letter " / " generally indicates that the preceding and following related objects are in an "or" relationship.

[0032] In the description of the embodiments of this application, the term "multiple" means two or more (including two), similarly, "multiple sets" means two or more sets (including two sets), and "multiple sheets" means two or more sheets (including two sheets).

[0033] In the description of the embodiments of this application, the orientations or positional relationships indicated by technical terms such as "center," "vertical direction," "horizontal direction," "length," "width," "wall thickness," "top," "bottom," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inside," "outside," "clockwise," "counterclockwise," "axial direction," "radial direction," and "circumferential direction" are based on the orientations or positional relationships shown in the drawings and are merely for the convenience and simplification of the description of the embodiments of this application. They do not necessarily suggest or imply that the shown devices or elements have a specific orientation or are constructed and operated in a specific orientation, and should not be understood as limiting the embodiments of this application.

[0034] In the description of the embodiments of this application, unless otherwise explicitly stated or limited, technical terms such as “attachment,” “coupling,” “connection,” and “fixing” should be understood in a broad sense. For example, these may be fixed connections, removable connections, or integrations; they may be mechanical or electrical connections; they may be direct connections or indirect connections via an intermediate medium; and they may refer to internal communication between two elements or an interaction relationship between two elements. Those skilled in the art will be able to understand the specific meaning of the above terms in the embodiments of this application depending on the specific circumstances.

[0035] In this application, the battery mainly consists of one or more battery cells, and the battery cell includes a housing, an end cover, and an electrode assembly housed within the housing, the electrode assembly being a component in which an electrochemical reaction occurs within the battery cell. Specifically, the electrode assembly is mainly formed by winding or laminating a positive electrode sheet and a negative electrode sheet, and a separator is usually provided between the positive electrode sheet and the negative electrode sheet.

[0036] During battery use, as the number of cycles increases, non-uniform deposition of metal ions causes dendrites to form on the surface of the negative electrode sheet. Once these dendrites grow to a certain extent, they can penetrate the separator and continue to grow along their longitudinal direction, coming into contact with the positive electrode sheet. This results in an electrical connection between the positive and negative electrodes within the battery, causing an internal short circuit and consequently reducing the battery's safety performance.

[0037] In view of this, this application provides an electrode assembly, a battery cell, a battery, and a power consumption device that can improve the safety performance of a battery. Electrode assembly

[0038] A first aspect of this application provides an electrode assembly comprising a positive electrode sheet, a negative electrode sheet, a separator provided between the positive electrode sheet and the negative electrode sheet, and an organic coating provided on the side of the positive electrode sheet facing the separator and / or on one side of the separator, the coating comprising organic particles that react with dendrites containing a metal element.

[0039] In the electrode assembly according to this application, the organic coating is provided on the side of the positive electrode sheet facing the separator and / or on one side of the separator, and contains organic particles that react with dendrites containing elemental metals. When the battery is in use, dendrites containing elemental metals may form inside it. When these dendrites grow to a certain extent, they come into contact with the organic particles in the organic coating and react, generating gas. This reduces the probability of a short circuit occurring inside the battery due to the electrical connection between the positive electrode sheet and the negative electrode sheet, and also increases the pressure inside the battery, causing the battery's explosion-proof valve to break and the pressure to be released. As a result, the risk of the battery exploding is reduced, and the safety performance of the battery can be improved.

[0040] In some embodiments of this application, the organic particles include a reactive group that reacts with dendrites containing elemental sodium metal. This reactive group can contribute to a rapid reaction with the dendrites containing elemental sodium metal, and furthermore, it effectively reduces the risk of internal short circuits and battery explosions caused by the electrical connection between the positive and negative electrodes by the dendrites, thereby improving the safety performance of the battery.

[0041] In some embodiments of this application, the reactive group includes one or more of the following: a carboxyl group, a hydroxyl group, an amino group, a thiol group, a phenolic hydroxyl group, and a biphenyl group. The above reactive groups readily react with dendrites containing elemental sodium metal and can further effectively reduce the electrical connection between the positive and negative electrodes due to the above dendrites, thereby further improving the safety performance of the battery.

[0042] In this application, the reactive groups contained in organic particles can be measured using instruments and methods known in the art. For example, they can be measured using an infrared spectrophotometer by the following method. (1) Power-on and self-test

[0043] a. Start the optical bench, printer, and computer in this order, and wait 3 minutes for the optical bench to stabilize after startup. b. Select the required software by clicking "Start" / "All Programs" / "Thermo sciScientific OMNIC" in that order, or by clicking the shortcut on the desktop. c. Self-test of the device: Once the software is started, the device will perform a self-test. d. The two indicators in the upper left corner of the host represent the laser and scanning indicators, respectively. The laser indicator is always on, and the scanning indicator blinks. If a malfunction occurs, the laser indicator will turn off. (2) Sample measurement

[0044] a. Set up the attenuated total reflectance (ATR) test stand vertically, attach the probe so that the tip of the probe is at a constant height from the stand, and click "Confirm" after the instrument self-test. b. Place the sample on the measurement window of the stand, and rotate the probe clockwise while keeping it aligned with the measurement window until it is very close to the sample. When a sound is heard, collect data and obtain an infrared absorption spectrum showing that the transmittance or absorbance changes according to the wavenumber or wavelength.

[0045] In the embodiments of this application, by selecting an appropriate material for the organic particles, the difficulty of reaction with sodium-containing metal elements can be reduced, thereby improving the safety performance of the battery and reducing the difficulty and cost of manufacturing the battery.

[0046] In some embodiments of this application, the material of the organic particles includes one or more of benzoic acid, benzophenone, indoleacetic acid, phenol, and biphenyl. The material of the above organic particles readily reacts with dendrites containing elemental sodium metal, and a large amount of gas (e.g., hydrogen gas) is generated during the reaction with the dendrites, causing the pressure inside the battery to rise rapidly, rupture the explosion-proof valve, and release the pressure early, thereby further improving the safety performance of the battery.

[0047] In embodiments of this application, the organic coating may include a coating having an appropriate shape, thereby contributing to the discharge of gases generated by the reaction between the organic coating and the dendrites and the directed deposition of sodium ions, and further improving the safety performance and cycle performance of the battery.

[0048] In some embodiments of this application, the organic coating includes one or more of the following: a network-type organic coating, a dot-type organic coating, and a stripe-type organic coating.

[0049] It should be understood that the organic coating may include one of the following: a network-type organic coating, a dot-type organic coating, and a stripe-type organic coating, or a combination of two or more types, and is not specifically limited to the embodiments of this application.

[0050] In the above embodiments, by using dot-shaped and stripe-shaped organic coatings, the gas generated by the reaction between the organic coating and dendrites can be guided and discharged, allowing the explosion-proof valve of the battery to be quickly punctured and the pressure released, further improving the safety performance of the battery. The mesh-shaped organic coating not only improves the safety performance of the battery but can also contribute to the directional deposition of sodium ions, thereby contributing to improved battery cycle performance.

[0051] In this application, the shape of the organic coating may be determined using equipment and methods well known in the art. For example, the distribution shape of the organic coating on the separator and cathode sheet can be observed using a scanning electron microscope (SEM).

[0052] In some embodiments of this application, the organic coating includes a dotted organic coating, where the distance between adjacent dotted organic coatings is 0.5 μm to 50 μm. By setting the distance between adjacent dotted organic coatings within this range, the organic coating can react with dendrites to reduce the electrical connection between the positive and negative electrodes caused by the dendrites. Furthermore, the gas generated by the reaction between the organic coating and the dendrites can be discharged from the electrode assembly along the gaps between the dotted organic coatings, and the explosion-proof valve of the battery can be rapidly ruptured to release the pressure, thereby further improving the safety performance of the battery.

[0053] In this application, the distance between adjacent point organic coatings is as known in the art and can be measured using instruments and methods known in the art, for example, by measuring the distance between adjacent point organic coatings using a scanning electron microscope (SEM).

[0054] In the above embodiment, the distance between adjacent point-like organic coatings may be the same or different, and can be designed according to the difficulty of the process and the actual needs.

[0055] In some examples, the distances between adjacent point-like organic coatings were 0.5 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, 5.5 μm, 6 μm, 6.5 μm, 7 μm, 7.5 μm, 8 μm, 8.5 μm, 9 μm, 9.5 μm, 10 μm, 10.5 μm, 11 μm, 11.5 μm, 12 μm, 12.5 μm, 13 μm, 13.5 μm, 14 μm, 14.5 μm, 15 μm, 15.5 μm, and 16 μm. , 17μm, 18μm, 19μm, 20μm, 21μm, 22μm, 23μm, 24μm, 25μm, 26μm, 27μm, 28μm, 29μm, 30μm, 31μm, 32μm, 33μm, 34μm, 35μm, 36μm, 37μm, 38μm, 39μm, 40μm, 41μm, 42μm, 43μm, 44μm, 45μm, 46μm, 47μm, 48μm, 49μm, 50μm, or a range that is a combination of any two of the above values. For example, the distance between adjacent point-like organic coatings may range from 1 μm to 49 μm, 2 μm to 46 μm, 5 μm to 41 μm, 10 μm to 36 μm, 15 μm to 32 μm, or 20 μm to 30 μm.

[0056] In some embodiments of this application, the organic coating includes a striped organic coating, where the distance between adjacent striped organic coatings is 0.5 μm to 50 μm. Setting the distance between adjacent striped organic coatings within this range facilitates the reaction between the organic coating and the dendrites, and allows the gas generated by the reaction between the organic coating and the dendrites to be quickly discharged from the electrode assembly, thereby causing the explosion-proof valve of the battery to rupture and release the pressure, and thereby further improving the safety performance of the battery.

[0057] In this application, the distance between adjacent striped organic coatings is as known in the art and can be measured using instruments and methods known in the art, for example, by measuring the distance between adjacent striped organic coatings using an electron scanning microscope (SEM).

[0058] In the above embodiment, the distance between adjacent striped organic coatings may be the same or different, and can be designed according to the difficulty of the process and the actual needs.

[0059] In some examples, the distance between adjacent striped organic coatings was 0.5 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, 5.5 μm, 6 μm, 6.5 μm, 7 μm, 7.5 μm, 8 μm, 8.5 μm, 9 μm, 9.5 μm, 10 μm, 10.5 μm, 11 μm, 11.5 μm, 12 μm, 12.5 μm, 13 μm, 13.5 μm, 14 μm, 14.5 μm, 15 μm, 15.5 μm, 1 The range may be 6μm, 17μm, 18μm, 19μm, 20μm, 21μm, 22μm, 23μm, 24μm, 25μm, 26μm, 27μm, 28μm, 29μm, 30μm, 31μm, 32μm, 33μm, 34μm, 35μm, 36μm, 37μm, 38μm, 39μm, 40μm, 41μm, 42μm, 43μm, 44μm, 45μm, 46μm, 47μm, 48μm, 49μm, 50μm, or a combination of any two of the above values. For example, the distance between adjacent striped organic coatings may range from 1 μm to 48 μm, 1.5 μm to 46 μm, 2.5 μm to 40 μm, 4 μm to 35 μm, 8 μm to 30 μm, 12 μm to 25 μm, or 14 μm to 20 μm.

[0060] In some embodiments of this application, the organic coating includes a mesh-like organic coating, where the average pore size of the pores in the mesh-like organic coating is 0.5 μm to 50 μm. Setting the average pore size of the pores in the mesh-like organic coating within this range improves the safety performance of the battery and also contributes to the directional deposition of sodium ions, thereby improving the battery's cycle performance.

[0061] In this application, the average pore diameter of the pores in the network organic coating has the meaning known in the art and can be measured using instruments and methods known in the art. The average pore diameter of the pores in the point-like organic coating can be measured, for example, using a scanning electron microscope (SEM).

[0062] In some examples, the average pore diameters of the pores in the mesh-like organic coating were 0.5 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, 5.5 μm, 6 μm, 6.5 μm, 7 μm, 7.5 μm, 8 μm, 8.5 μm, 9 μm, 9.5 μm, 10 μm, 10.5 μm, 11 μm, 11.5 μm, 12 μm, 12.5 μm, 13 μm, 13.5 μm, 14 μm, 14.5 μm, 15 μm, 15.5 μm, and 16 μm. The range may be μm, 17μm, 18μm, 19μm, 20μm, 21μm, 22μm, 23μm, 24μm, 25μm, 26μm, 27μm, 28μm, 29μm, 30μm, 31μm, 32μm, 33μm, 34μm, 35μm, 36μm, 37μm, 38μm, 39μm, 40μm, 41μm, 42μm, 43μm, 44μm, 45μm, 46μm, 47μm, 48μm, 49μm, 50μm, or a combination of any two of the above values. For example, the average pore diameter range in a mesh-like organic coating may be 1 μm to 49 μm, 1.5 μm to 45 μm, 2 μm to 41 μm, 4 μm to 34 μm, 9 μm to 29 μm, 13 μm to 23 μm, or 16 μm to 20 μm.

[0063] In some embodiments of this application, the organic coating is provided on the separator-facing side of the positive electrode sheet. By providing the organic coating on the separator-facing side of the positive electrode sheet, the occurrence of internal short circuits in the battery caused by the electrical connection between the positive and negative electrodes by dendrites can be effectively reduced, and the safety performance of the battery can be further improved.

[0064] In some embodiments of this application, the thickness of the organic coating is 2 μm to 10 μm. By setting the thickness of the organic coating within this range, the safety performance of the battery can be further improved, and by providing an appropriate thickness to the organic coating, a larger amount of active material can be filled, contributing to an improvement in the energy density of the battery.

[0065] In this application, the thickness of the organic coating is as known in the art and can be measured using methods well known in the art, such as a micrometer (e.g., Mitutoyo 293-100, with an accuracy of 0.1 μm).

[0066] In some examples, the thickness of the organic coating was 2 μm, 2.1 μm, 2.2 μm, 2.3 μm, 2.4 μm, 2.5 μm, 2.6 μm, 2.7 μm, 2.8 μm, 2.9 μm, 3 μm, 3.1 μm, 3.2 μm, 3.3 μm, 3.4 μm, 3.5 μm, 3.6 μm, 3.7 μm, 3.8 μm, 3.9μm, 4μm, 4.1μm, 4.2μm, 4.3μm, 4.4μm, 4.5μm, 4.6μm, 4.7μm, 4.8μm, 4.9μm, 5μm , 5.1μm, 5.2μm, 5.3μm, 5.4μm, 5.5μm, 5.6μm, 5.7μm, 5.8μm, 5.9μm, 6μm, 6.1μm, 6. The range may be 2μm, 6.3μm, 6.4μm, 6.5μm, 6.6μm, 6.7μm, 6.8μm, 6.9μm, 7μm, 7.1μm, 7.2μm, 7.3μm, 7.4μm, 7.5μm, 7.6μm, 7.7μm, 7.8μm, 7.9μm, 8μm, 8.1μm, 8.2μm, 8.3μm, 8.4μm, 8.5μm, 8.6μm, 8.7μm, 8.8μm, 8.9μm, 9μm, 9.1μm, 9.2μm, 9.3μm, 9.4μm, 9.5μm, 9.6μm, 9.7μm, 9.8μm, 9.9μm, 10μm, or any combination of any two of the above values, but is not limited to these ranges. For example, the thickness range of the organic coating may be 2.1 μm to 9.8 μm, 2.5 μm to 9.2 μm, 3.1 μm to 8.5 μm, 3.5 μm to 8 μm, 3.9 μm to 7.4 μm, or 4.3 μm to 6.8 μm.

[0067] In some embodiments of this application, the separator comprises a first base film and a second base film, and the organic coating is provided between the first and second base films. By including the first and second base films in the separator, the mechanical strength of the separator can be enhanced, and penetration of the separator by dendrites can be suppressed. Furthermore, by providing the organic coating between the first and second base films, the organic particles in the organic coating react with dendrites that have penetrated the first or second base film, further suppressing the dendrites from completely penetrating the separator, thereby further improving the safety performance of the battery.

[0068] In some embodiments of this application, the thickness of the organic coating is 2 μm to 10 μm.

[0069] In some embodiments of this application, the thickness of the first base film and the second base film is independently 5 μm to 20 μm.

[0070] In this application, the thicknesses of the first base film and the second base film are as known in the art and can be measured using methods well known in the art, such as a micrometer (e.g., Mitutoyo 293-100, with an accuracy of 0.1 μm).

[0071] In the embodiments described above, the material and thickness of the first base film and the second base film may be the same or different, but the material and thickness of the first base film and the second base film can be selected according to the actual application needs, and the embodiments of this application are not specifically limited.

[0072] In some examples, any known separator with excellent chemical and mechanical stability can be selected as the separator. For example, the separator may include one or more porous polyolefin resin films (e.g., polyethylene, polypropylene, polyvinylidene fluoride), porous glass fibers, and porous nonwoven fabrics. The porous separator may be a single-layer film or a multilayer composite film. If the porous separator is a multilayer composite film, the materials of each layer may be the same or different.

[0073] Note that the above-mentioned parameters related to the separator and organic coating are all one-sided parameters.

[0074] In some embodiments of this application, the surface density of the organic coating is 1.5 g / m². 2 ~4.0g / m 2 Therefore, by setting the surface density of the organic coating within the above range, the organic coating can effectively reduce the electrical connection between the positive and negative electrodes due to dendrites.

[0075] In this application, the above-mentioned surface density refers to the surface density of the organic coating on one side surface, and is in the sense known in the art and can be tested by methods known in the art. For example, it can be tested according to the following steps: The sampled sample is punched out into a small circular sheet with an area of ​​S1, its mass is weighed and recorded as M1. Then, the coating on the weighed sample is removed, the mass of the substrate is weighed and recorded as M0, (1) When the organic coating is present on only one side of the substrate, the surface density of the organic coating on that side is (M1-M0) / S1, (2) When both sides of the substrate have an organic coating, the surface density of the organic coating on one side is (M1-M0) / S1 / 2.

[0076] In some examples, the surface density of the organic coating is 1.5 g / m². 2, 1.6 g / m 2 , 1.7 g / m 2 , 1.8 g / m 2 , 1.9 g / m 2 , 2 g / m 2 , 2.1 g / m 2 , 2.2 g / m 2 , 2.3 g / m 2 , 2.4 g / m 2 , 2.5 g / m 2 , 2.6 g / m 2 , 2.7 g / m 2 , 2.8 g / m 2 , 2.9 g / m 2 , 3 g / m 2 , 3.1 g / m 2 , 3.2 g / m 2 , 3.3 g / m 2 , 3.4 g / m 2 , 3.5 g / m 2 , 3.6 g / m 2 , 3.7 g / m 2 , 3.8 g / m 2 , 3.9 g / m 2 , 4 g / m 2 [[ID=五十]], or it may be a range combined with any two of the above numerical values, but is not limited thereto. For example, the range of the areal density of the organic coating is 1.6 g / m 2 ~3.8 g / m 2 , 1.8 g / m 2 ~2.5 g / m 2 , 2 g / m 2 ~2.3 g / m 2 may also be.

[0077] In some embodiments of this application, the organic coating further contains an adhesive, and the mass ratio of the adhesive to the organic particles is (1-5):(10-90) based on the mass of the organic coating. The addition of the adhesive increases the viscosity of the organic coating, further strengthens the bonding force between the organic coating and the positive electrode sheet, negative electrode sheet, and separator, and reduces peeling of the organic coating. Furthermore, when the mass ratio of the adhesive to the organic particles satisfies the above relationship, the organic coating can react with the dendrites to reduce them while maintaining good viscosity, thereby further improving the safety performance of the battery.

[0078] In some embodiments of this application, the mass content of the adhesive in the organic coating is 1% to 5%.

[0079] In some examples, the adhesive may contain one or more of the following: styrene-butadiene rubber (SBR), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyvinyl butyral (PVB), aqueous acrylic resin, and carboxymethylcellulose (CMC).

[0080] In some embodiments of this application, the mass content of organic particles in the organic coating is 80% to 90%. By setting the mass content of organic particles in the organic coating to the above range, the organic coating reacts with more elemental metals, further reducing the possibility of the positive and negative electrodes being electrically connected by dendrites, thereby more effectively improving the safety performance of the battery.

[0081] In some embodiments of this application, the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer provided on one side of the positive electrode current collector and containing a positive electrode active material. In the embodiments of this application, the positive electrode current collector and the positive electrode active material are not particularly limited, and well-known positive electrode current collectors and positive electrode active materials in the art can be used.

[0082] In some embodiments of this application, the positive electrode active material may include one or more of the following: sodium transition metal oxides, polyanionic compounds, and Prussian blue compounds. In some other embodiments of this application, several other known materials that can be used as positive electrode active materials for sodium-ion batteries may be used.

[0083] In some examples, the transition metal in sodium transition metal oxides may include one or more of the following: Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr, and Ce. For example, if the sodium transition metal oxide is Na x In the case of MO2, M may be one or more of the following: Ti, V, Mn, Co, Ni, Fe, Cr, and Cu. <x≦1である。

[0084] In several other examples, polyanionic compounds include sodium ions, transition metal ions, and tetrahedral (YO4) ions. n- The group of compounds may include anionic units, where the transition metal may include one or more of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr, and Ce, Y may include one or more of P, S, and Si, and n is (YO4) n- It represents the valence.

[0085] Polyanionic compounds include sodium ions, transition metal ions, and tetrahedral (YO4) ions. n- The group of compounds may include anionic units and halogen anions, where the transition metal may include one or more of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr, and Ce, Y may include one or more of P, S, and Si, and n is (YO4) n- This represents the valency, and the halogen may include one or more of F, Cl, and Br.

[0086] In some specific embodiments, the polyanionic compound is NaFePO4, Na3V2(PO4)3, NaM'PO4F (where M' includes one or more of V, Fe, Mn, and Ni), and Na3(VOy)2(PO4)2F 3-2y It may include one or more of the following types (0≦y≦1):

[0087] In some cases, Prussian blue compounds contain sodium ions, transition metal ions, and cyanuric ions (CN - The group of compounds may also have ). The transition metal may be at least one of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr, and Ce. The Prussian blue compound is, for example, Na a Me b Me' c (CN)6, where Me and Me' each independently contain one or more of Ni, Cu, Fe, Mn, Co, and Zn, 0 <a≦2、0<b<1、0<c<1である。

[0088] In some embodiments of this application, the positive electrode active material layer may further contain a conductive agent and an adhesive. In embodiments of this application, the types of conductive agent and adhesive contained in the positive electrode active material layer are not particularly limited and may be selected according to actual needs.

[0089] For example, the conductive agent may be one or more of graphite, superconducting carbon, acetylene black, carbon black, Ketjenblack, carbon dots, carbon nanotubes, graphene, and carbon nanofibers, but is not limited to these. The adhesive may be one or more of styrene-butadiene rubber (SBR), aqueous acrylic resin, carboxymethylcellulose (CMC), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyvinyl butyral (PVB), ethylene vinyl acetate copolymer (EVA), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, fluorine-containing acrylic resin, and polyvinyl alcohol (PVA), but is not limited to these.

[0090] In some embodiments of this application, the positive electrode current collector may be made of a material such as metal foil or a porous metal plate. For example, the material of the positive electrode current collector may be, but is not limited to, foil or a porous plate made of a metal such as copper, nickel, titanium, or silver, or an alloy thereof. Furthermore, in some specific embodiments of this application, aluminum foil is used as the positive electrode current collector.

[0091] In the embodiments of this application, a positive electrode active material, a conductive agent, and an adhesive are thoroughly stirred and mixed in a suitable amount of N-methylpyrrolidone (NMP) in a constant mass ratio to form a uniform positive electrode slurry, and a positive electrode sheet is obtained by applying the positive electrode slurry to the surface of an aluminum foil which is a positive electrode current collector, drying, cold pressing, and die cutting.

[0092] In some embodiments of this application, the negative electrode sheet includes a negative electrode current collector. In some examples, the negative electrode current collector may be made of an electronically conductive material. For example, the material of the negative electrode current collector may be copper foil, nickel foil, stainless steel foil, etc.

[0093] In some embodiments of this application, the negative electrode sheet is provided on the negative electrode current collector side and may further include a negative electrode active material layer containing a negative electrode active material, but the type of negative electrode active material is not particularly limited and can be selected by those skilled in the art according to their actual needs. For example, the negative electrode active material may include one or more types of carbon materials, alloy materials, transition metal oxides, transition metal sulfides, phosphorus-based materials, and titanate materials. In some specific embodiments, the negative electrode active material includes a carbon material.

[0094] In some examples, the carbon material may include one or more of the following: natural graphite, artificial graphite, mesophase carbon microspheres (MCMB), hard carbon, and soft carbon. The alloy material may include one or more of the following: alloy materials composed of multiple elements from Si, Ge, Sn, Pb, and Sb. The chemical formula of the transition metal oxide is, for example, M 1 u O v And here, M 1 may be one or more types selected from Fe, Co, Ni, Cu, Mn, Sn, Mo, Sb, and V, where au = 2v and a is M 1 This is the valency. The chemical formula of a transition metal sulfide is, for example, M 2 i S j And M 2 may include one or more of the following elements: Fe, Co, Ni, Cu, Mn, Sn, Mo, Sb, and V, where bi = 2j and b is M 2 This is the valence. The phosphorus-based material may contain one or more types of red phosphorus, white phosphorus, and black phosphorus. The titanate material is Na2Ti3O7, Na2Ti6O 13 Na4Ti5O 12 Li4Ti5O 12 It may contain one or more types of NaTi2(PO4)3.

[0095] In some embodiments of this application, the negative electrode active material layer may further include a conductive agent and an adhesive. In embodiments of this application, the types of conductive agent and adhesive in the negative electrode active material layer are not particularly limited and may be selected according to actual needs.

[0096] For example, the conductive agent may be one or more of graphite, superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers, but is not limited to these. The adhesive may be one or more of styrene-butadiene rubber (SBR), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyvinyl butyral (PVB), aqueous acrylic resin, and carboxymethylcellulose (CMC), but is not limited to these.

[0097] In the embodiments of this application, a negative electrode sheet is obtained by mixing a negative electrode active material, a conductive agent, and an adhesive in a fixed mass ratio, stirring thoroughly with an appropriate amount of deionized water to form a uniform negative electrode slurry, and then applying the negative electrode slurry to the surface of a negative electrode current collector, followed by drying, cold pressing, and diamond cutting.

[0098] In embodiments of this application, the electrode assembly can be manufactured using methods well known in the art, for example, by performing a winding process and / or a lamination process on a positive electrode sheet, a separator, and a negative electrode sheet. battery cell

[0099] A second aspect of this application provides a battery cell including an electrode assembly according to the first aspect of this application.

[0100] In some embodiments of this application, the battery cell further comprises an electrolyte, the electrolyte comprising an organic solvent and an electrolyte sodium salt. The types of electrolyte sodium salt and organic solvent are not particularly limited and may be selected according to actual needs. The electrolyte may also comprise an organic solvent and an electrolyte sodium salt.

[0101] In some embodiments of this application, the organic solvent includes an ether-based organic solvent, for example, the ether-based organic solvent includes one or more of diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, or tetraethylene glycol dimethyl ether, and tetrahydrofuran.

[0102] In some embodiments of this application, the molar concentration of the electrolyte sodium salt in the electrolyte is 0.5 mol / L to 3 mol / L, and the electrolyte sodium salt may include one or more of the following: sodium hexafluoride phosphate, sodium borofluoride, sodium bis(trifluoromethylsulfonyl)amide, sodium bis(fluorosulfonyl)amide, and sodium bis(oxalato)boric acid.

[0103] In some embodiments of this application, the electrolyte may optionally further include additives. For example, the additives may include negative electrode film-forming additives, positive electrode film-forming additives, or additives capable of improving some performance of the battery cell, such as overcharge performance, high-temperature performance, or low-temperature output performance.

[0104] In some embodiments of this application, the battery cell may further include an outer casing, which may be used to package the electrode assembly and electrolyte.

[0105] In some embodiments of this application, the exterior structure of the battery cell may be a hard case, such as a rigid plastic case, an aluminum case, or a steel case. The exterior structure of the battery cell may also be a soft pack, such as a bag-shaped soft pack. The material of the soft bag may be plastic, and may be at least one of polypropylene (PP), polybutylene terephthalate (PBT), and polybutylene succinate (PBS).

[0106] In this application, the shape of the battery cell is not particularly limited and may be cylindrical, rectangular, or any other shape. Figure 1 shows a rectangular battery cell 5 as an example.

[0107] In some embodiments of this application, as shown in Figure 2, the exterior structure may include a housing 51 and a cover plate 53. The housing 51 may include a bottom plate and side plates connected to the bottom plate, and the bottom plate and side plates surround and form a housing cavity. The housing 51 has an opening that communicates with the housing cavity, and the cover plate 53 covers the opening to seal the housing cavity. Furthermore, the cover plate 53 is provided with an explosion-proof valve, and when the internal pressure of the housing reaches a predetermined value, the gas pressure ruptures the explosion-proof valve, causing the valve to open and release the gas, thereby preventing the explosion of the battery cell. The positive electrode sheet, negative electrode sheet and separator can be formed by a winding process and / or a lamination process to form an electrode assembly 52. ​​The electrode assembly 52 is packaged in the housing cavity. The electrolyte is impregnated into the electrode assembly 52. ​​The number of electrode units 52 contained in the battery cell 5 may be one or more and can be increased or decreased according to the needs.

[0108] The method for manufacturing a battery cell described in this application is a known method. In some embodiments of this application, a positive electrode sheet, a separator, a negative electrode sheet, and an electrolyte can be assembled to form a battery cell. For example, a battery cell can be obtained by forming an electrode assembly by winding and / or laminating the positive electrode sheet, a separator, and a negative electrode sheet, placing the electrode assembly in an outer structure, injecting the electrolyte after drying, and performing processes such as vacuum packaging, settling, chemical conversion, and shaping. battery

[0109] A third aspect of this application provides a battery including a battery cell according to a second aspect of this application.

[0110] In embodiments of this application, to meet different power requirements, the battery may include multiple battery cells, where a battery cell refers to the smallest unit constituting a battery module or battery pack. Multiple battery cells are connected in series and / or parallel via electrode terminals and can be applied to a variety of applications. The battery according to embodiments of this application includes a battery module or battery pack, where multiple battery cells can be connected in series, parallel, or a combination of series and parallel, where a combination of series and parallel means a combination of series and parallel connections. In embodiments of this application, multiple battery cells may be assembled directly into a battery pack, or battery modules may be assembled first, and then the battery modules may be used to assemble the battery pack.

[0111] In some embodiments of this application, the battery cell according to the second aspect of this application may be assembled as a battery module, and the number of battery cells included in the battery module may be multiple, and the specific number can be increased or decreased depending on the application and capacity of the battery module.

[0112] Figure 3 is a schematic diagram of an example battery module. As shown in Figure 3, multiple battery cells 5 may be arranged sequentially along the longitudinal direction of the battery module 4. Of course, they may be arranged in any other manner. Furthermore, these multiple battery cells 5 may be fixed together with fasteners.

[0113] Optionally, the battery module 4 may further include a housing having a housing space for accommodating multiple battery cells 5.

[0114] In some embodiments of this application, the above-mentioned battery modules may be assembled as a battery pack, and the number of battery modules included in the battery pack can be increased or decreased depending on the application and capacity of the battery pack.

[0115] Figures 4 and 5 are schematic diagrams of an example battery pack configuration. As shown in Figures 4 and 5, the battery pack 1 may include a battery case and a plurality of battery modules 4 provided in the battery case. The battery case includes an upper housing 2 and a lower housing 3, the upper housing 2 is provided so as to cover the lower housing 3 and forms a sealed space for housing the battery modules 4. The plurality of battery modules 4 may be arranged in any way within the battery case. power consumption equipment

[0116] A fourth aspect of this application provides a power consumption device comprising one or more types of battery cells, battery modules, or battery packs according to a second aspect of this application. The battery cells, battery modules, or battery packs may be used as a power source for the power consumption device or as an energy storage unit for the power consumption device.

[0117] In this application, power consumption devices may include, but are not limited to, mobile phones, tablet computers, laptop computers, electric toys, power tools, battery cars, electric vehicles, ships, aircraft, and energy storage systems. However, electric toys may be stationary or mobile electric toys, and may include, for example, game consoles, electric vehicle toys, electric boat toys and electric airplane toys, and spacecraft may include airplanes, rockets, space shuttles and spaceships.

[0118] Furthermore, the power consumption device may select battery cells, battery modules, or battery packs according to its usage needs.

[0119] Figure 6 is a schematic diagram of an example power consumption device. This power consumption device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc. A battery pack or battery module can be used to meet the high power and high energy density requirements of this power consumption device.

[0120] The following examples illustrate the contents disclosed in this application in more detail, and are provided only as illustrative examples, as it will be apparent to those skilled in the art that various modifications and changes are possible within the scope of the contents disclosed in this application. All reagents used in the examples may be commercially available, synthesized according to conventional methods, and may be used as is without further processing. All equipment used in the examples is commercially available. Example 1

[0121] Manufacturing of positive electrode sheets

[0122] A positive electrode sheet is obtained by thoroughly stirring and mixing NaFePO4, a positive electrode active material, acetylene black, a conductive agent, and carboxymethylcellulose, an adhesive, in a mass ratio of 95:2:3 in an appropriate amount of N-methylpyrrolidone (NMP) to form a uniform positive electrode slurry, and then applying the positive electrode slurry to the surface of aluminum foil, which is a positive electrode current collector, followed by drying, cold pressing, and die cutting. Manufacturing of negative electrode sheets

[0123] A negative electrode sheet is obtained by mixing artificial graphite, which is the negative electrode active material, acetylene black, which is the conductive agent, and carboxymethylcellulose, which is the adhesive, in a mass ratio of 94:5:1 and stirring thoroughly with an appropriate amount of deionized water to form a uniform negative electrode slurry, and then applying the negative electrode slurry to the surface of copper foil, which is the negative electrode current collector, and drying, cold pressing, and die cutting. Separator

[0124] A double-layer polyethylene film with each layer having a thickness of 10 μm is used. Manufacturing of organic coatings

[0125] Biphenyl organic particles and carboxymethylcellulose adhesive were stirred and mixed in a mass ratio of 7:1 to prepare an organic coating slurry. This organic coating slurry was then applied between two layers of polyethylene film and dried to a thickness of 4 μm and a surface density of 2.0 g / m². 2Obtain an organic coating. Manufacturing of electrolyte

[0126] In a glove box filled with argon gas containing less than 1 ppm of water, diethylene glycol dimethyl ether and tetrahydrofuran are mixed in a mass ratio of 1:3, and sodium hexafluoride phosphate (NaPF6) at a concentration of 1.0 mol / L is added and the mixture is homogenized to obtain the electrolyte. Manufacturing of sodium-ion rechargeable batteries

[0127] A sodium-ion secondary battery is obtained by forming an electrode assembly on a positive electrode sheet, a separator, and a negative electrode sheet using a winding process and / or a lamination process, placing the electrode assembly in an outer structure, injecting an electrolyte after drying, and then performing processes such as vacuum packaging, standing, chemical conversion, and shaping. Examples 2-10

[0128] The manufacturing method is similar to that of Example 1, with the difference being the components of the organic coating and their content. Comparative Example 1

[0129] The manufacturing method is similar to that of Example 1, the only difference being that the electrode assembly does not include an organic coating. Examples 11-18

[0130] The manufacturing method is similar to that of Example 1, with the differences being the thickness and surface density of the organic coating. Test section (1) Gas generation rate test

[0131] The test method is: The steps include: baking an assembled battery, injecting electrolyte, sealing the battery's electrolyte injection port, activating it at room temperature, and then welding metal bands to the positive and negative electrode sheets of the battery to obtain an activated battery, wherein the battery's electrolyte injection port is sealed with masking tape made of OPP beige tape, an aluminum band is welded to the positive electrode sheet using an ultrasonic welding machine, and a nickel band is welded to the negative electrode sheet using an internal resistance electric welding machine. The step involves fixing the activated battery to a jig and connecting the metal bands of the positive electrode sheet and negative electrode sheet to the positive and negative electrodes of the charging and discharging equipment with leads, the leads being 2.5 mm 2 It is a copper wire, with an alligator clip welded to one end connected to a metal band, the charge / discharge equipment is a lithium battery chemical formation test cabinet, the charge / discharge equipment is installed in a drying plant with a dew point of 5°C or less, humidity of 20%RH or less, and a temperature of 28°C or less, The steps include turning on the power, pre-charging the activated battery, recording the time and the value of the numerical pressure gauge when the explosion-proof valve ruptures before and during charging, The process includes the steps of calculating the time t and pressure P required for the explosion-proof valve to rupture based on the numerical values ​​of a numerical pressure gauge recorded before and after charging, calculating the gas volume V based on PV=nRT, and further calculating the gas generation rate based on V / t, wherein the threshold for the explosion-proof valve to rupture is 0.65 MPa.

[0132] Table 1 shows the relevant parameters and test results for the organic coatings in Examples 1-10 and Comparative Example 1, respectively.

[0133] [Table 1]

[0134] According to Table 1, a comparison of the test structures of Examples 1-10 and Comparative Example 1 shows that in the electrode assembly according to this application, an organic coating is provided on the side of the positive electrode sheet facing the separator and / or on one side of the separator. The organic coating contains organic particles that react with dendrites containing elemental metals. Therefore, when the battery is in use, dendrites containing elemental metals may be generated inside the battery. When these dendrites grow to a certain extent, they come into contact with the organic particles in the organic coating and react, generating gas. This reduces the probability of a short circuit occurring inside the battery due to the electrical connection between the positive electrode sheet and the negative electrode sheet, and also increases the pressure inside the battery, causing it to break the explosion-proof valve and release the pressure. As a result, the risk of the battery exploding is reduced, and the safety performance of the battery can be improved.

[0135] Table 2 shows the relevant parameters and test results for the organic coatings in Examples 11 to 18, respectively.

[0136] [Table 2]

[0137] Table 2 shows that when the thickness and surface density of the organic coating are within appropriate ranges, the rate of gas generation due to the reaction between the dendrites and the organic particles contained in the organic coating can be increased. This reduces the probability of internal short circuits occurring due to electrical connection between the positive and negative electrode sheets, and also reduces the risk of the battery exploding because the internal pressure rises quickly, rupturing the battery's explosion-proof valve and releasing the pressure. Thus, the safety performance of the battery can be improved.

[0138] The above embodiments are not intended to limit the technical solutions of this application, but are merely illustrative. While this application is described in detail with reference to the above embodiments, those skilled in the art will understand that modifications to the technical solutions described in the above embodiments, or substitution of some or all of the technical features therein, are possible, and that any such modifications should be included within the scope of the claims and specification of this application, as long as they deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of this application. In particular, the technical features referred to in each embodiment can be combined in any way, provided there is no structural inconsistency. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions included within the claims.

Claims

1. Positive electrode sheet and Negative electrode sheet and A separator comprising a first base film and a second base film, and provided between the positive electrode sheet and the negative electrode sheet, The system comprises an organic coating provided between the first base film and the second base film, which contains organic particles that react with dendrites containing elemental sodium metal to generate gas, Electrode assembly for sodium-ion secondary batteries.

2. The organic particles contain a reactive group that reacts with a dendrite containing elemental sodium metal. The electrode assembly for a sodium-ion secondary battery according to claim 1.

3. The reactive group comprises one or more of the following: a carboxyl group, a hydroxyl group, an amino group, a thiol group, a phenolic hydroxyl group, and a biphenyl group. The electrode assembly for a sodium-ion secondary battery according to claim 2.

4. The material of the organic particles includes one or more of the following: benzoic acid, benzophenone, indoleacetic acid, phenol, and biphenyl. The electrode assembly for a sodium-ion secondary battery according to claim 1.

5. The organic coating includes one or more types from among a network-type organic coating, a dot-type organic coating, and a stripe-type organic coating. The electrode assembly for a sodium-ion secondary battery according to claim 1.

6. The thickness of the aforementioned organic coating is 2 μm to 10 μm. The electrode assembly for a sodium-ion secondary battery according to claim 1.

7. The thickness of the aforementioned organic coating is 2 μm to 10 μm. and / or, the thickness of the first base film is 5 μm to 20 μm, and / or, the thickness of the second base film is 5 μm to 20 μm. The electrode assembly for a sodium-ion secondary battery according to claim 1.

8. The surface density of the aforementioned organic coating is 1.5 g / m². ２ ~4.0 g / m ２ That is, The electrode assembly for a sodium-ion secondary battery according to claim 1.

9. The organic coating further comprises an adhesive, and based on the mass of the organic coating, the mass ratio of the adhesive to the organic particles is (1-5):(10-90). The electrode assembly for a sodium-ion secondary battery according to claim 1.

10. The mass content of the adhesive in the organic coating is 1% to 5%, The mass content of the organic particles in the organic coating is 80% to 90%. The electrode assembly for a sodium-ion secondary battery according to claim 9.

11. A battery cell comprising an electrode assembly for a sodium-ion secondary battery according to any one of claims 1 to 10.

12. A battery comprising the battery cell described in claim 11.

13. A power consumption device including a battery as described in claim 12.

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