Electrode assembly, battery cell, battery, and power consumption device

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 to Related Applications This application claims priority to Chinese Patent Application No. 202310070849.5, titled "Electrode Assembly, Battery Cell, Battery, and Power Consumption Device", filed on January 17, 2023, and all contents of the said application are incorporated herein by reference.

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

Background Art

[0003] With the shortage of conventional energy, new energy has gradually become one of the important types of energy in various industries. Here, the battery is one of the representatives of new energy. With the rapid development of technology, batteries are widely used in various industries such as electric tools, electric vehicles, and energy storage facilities. To meet the increasing needs in various industries, the requirements for battery performance, such as the safety performance of the battery, are also becoming increasingly high. Therefore, in order to meet the increasing needs in various industries, there is a strong demand for improving the safety performance of batteries.

Summary of the Invention

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

[0005] The first aspect of this application provides an electrode assembly including 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 organic coating containing organic particles that react with dendrites composed 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. During the use of the battery, dendrites containing a single metal may be generated inside it. When these dendrites grow to a certain extent, they come into contact with and react with the organic particles in the organic coating, generating gas. As a result, the probability of a 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, so 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 and negative electrodes 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 easily reacts with dendrites containing a single sodium metal, and can further effectively reduce the electrical connection between the positive and negative electrodes 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, indoleacetic acid, phenol, and biphenyl.

[0010] According to any of the above embodiments of the first aspect of the present application, the organic coating includes one or more of 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 the present application, the organic coating is provided on the side facing the separator of the positive electrode sheet. By providing the organic coating on the side facing the separator of the positive electrode sheet, the occurrence of internal short circuit of the battery caused by the electrical connection between the positive electrode and the negative electrode due to 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 the present application, the thickness H1 of the organic coating is 2 μm to 10 μm. When the thickness of the organic coating is within the above range, the safety performance of the battery can be further improved, and by giving the organic coating an appropriate thickness, more active material can be filled, contributing to the improvement of the energy density of the battery.

[0013] According to any of the above embodiments of the first aspect of the present 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 base film and the second base film in the separator, the mechanical strength of the separator can be increased, and further, the penetration of the separator by dendrites can be suppressed. Also, by providing the organic coating between the first base film and the second base film, the organic particles in the organic coating react with the dendrites that have penetrated the first base film or the second base film, further suppressing 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 the present application, the thickness of the organic coating is 2 μm to 10 μm. When the thickness of the organic coating is within the above range, the probability that the positive electrode and the negative electrode are electrically connected by dendrites is reduced, improving the safety performance of the battery. At the same time, the filling space of the active material can be increased, and the energy density of the battery can be improved.

[0015] According to any of the above embodiments of the first aspect of the present 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 the present 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 the present application, the areal density of the organic coating is 1.5 g / m 2 ~4.0 g / m 2 . When the areal density of the organic coating is within the above range, the organic coating can effectively reduce the electrical connection between the positive electrode and the negative electrode by dendrites.

[0018] According to any of the above embodiments of the first aspect of the present application, the organic coating further contains an adhesive. Based on the mass of the organic coating, the mass ratio of the adhesive to the organic particles is (1 to 5):(10 to 90). By adding the adhesive, the viscosity of the organic coating increases, and furthermore, the bonding force between the organic coating and the positive electrode sheet, the negative electrode sheet, and the separator becomes stronger, reducing the peeling of the organic coating. In addition, when the mass ratio of the adhesive to the organic particles satisfies the above relationship, the organic coating can react with dendrites to reduce dendrites 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 the present 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 the present application, the mass content of the organic particles in the organic coating is 80% to 90%. When the mass content of the organic particles in the organic coating is within the above range, the organic coating reacts with more elemental metals, further reducing the possibility that the positive and negative electrodes are electrically connected by dendrites, thereby more effectively improving the safety performance of the battery.

[0021] The second aspect of the present application provides a battery cell including the electrode assembly according to the first aspect of the present application.

[0022] The third aspect of the present application provides a battery including the battery cell according to the second aspect of the present application.

[0023] The fourth aspect of the present application provides a power consumption device including the battery according to the third aspect of the present application.

[0024] The above description is only a summary of the technical solutions of the present application. In order to more clearly understand the technical means of the present application, it can be implemented according to the content of the specification. Also, in order to more clearly and easily understand the above and other objects, features and advantages of the present application, specific embodiments of the present application are listed below.

Brief Description of the Drawings

[0025] Those skilled in the art will appreciate various other advantages and effects by reading the detailed description of the following alternative embodiments. The drawings are only for showing alternative embodiments and do not limit the present application. Also, in all the drawings, the same members are denoted by the same reference numerals. The drawings are not necessarily drawn to actual scale.

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

[0026] [[ID=1N2]] 1 Battery pack, 2 Upper housing, 3 Lower housing, 4 Battery module, 5 Battery cell, 51 Housing, 52 Electrode assembly, 53 Cover plate.

Embodiments for Carrying Out the Invention

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

[0028] Unless otherwise specified, all technical terms and scientific terms used in this specification have the same meaning as those commonly understood by those skilled in the technical field to which the present application belongs. The terms used in this specification are merely for explaining specific embodiments, and are not intended to limit the present application. The terms "including" and "having" and any variations thereof included in the description of the specification, claims, and above drawings of the present application are intended to cover non-exclusive inclusion.

[0029] In the description of the embodiments of the present application, technical terms such as "first" and "second" are merely for distinguishing different objects, and should not be understood as indicating or implying relative importance, or implicitly indicating the number or specific order of the indicated technical features, or their primary-secondary relationship. In the description of the embodiments of the present application, "a plurality" means two or more unless specifically and clearly limited.

[0030] As used herein, the term "example" means that the specific features, structures, or characteristics described in connection with the example may be included in at least one example of the present application. Each occurrence of this phrase described in each part of this specification does not necessarily refer to the same example, nor is it an independent or alternative example mutually exclusive with other examples. It can 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 examples of the present application, the term "and / or" is only used to explain the relationship of the relevant objects, indicating that there may be three situations. For example, A and / or B indicates that there may be three cases: A exists alone, A and B exist simultaneously, and B exists alone. Also, the character " / " in this specification generally indicates that the relevant objects before and after are in an "or" relationship.

[0032] In the description of the examples of the present application, the term "plurality" means two or more (including two). Similarly, "a plurality of sets" means two or more sets (including two sets), and "a plurality of sheets" means two or more sheets (including two sheets).

[0033] In the description of the examples of the present application, the orientation or positional relationship indicated by technical terms such as "center", "longitudinal direction", "lateral direction", "length", "width", "wall thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial direction", "radial direction", "circumferential direction", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience and simplification of the description of the examples of the present application, and does not imply or suggest that the indicated device or element necessarily has a specific orientation or is structured and operated in a specific orientation. Therefore, it should not be understood as limiting the examples of the present application.

[0034] In the description of the embodiments of the present application, unless otherwise clearly defined or limited, technical terms such as "attachment", "coupling", "connection", "fixation", etc. should be understood in a broad sense. For example, it may be a fixed connection, a removable connection, or an integration, and may be a mechanical connection or an electrical connection, and may be a direct connection or an indirect connection through an intermediate medium, or may be a communication within two elements or an interaction relationship between two elements. A person skilled in the art can understand the specific meaning of the above terms in the embodiments of the present application according to the specific situation.

[0035] In the present application, a battery is mainly composed of one or more battery cells. A battery cell includes a housing, an end cover, and an electrode assembly accommodated in the housing. The electrode assembly is a member 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 usually, a separator is provided between the positive electrode sheet and the negative electrode sheet.

[0036] During the use of the battery, as the number of cycles increases, dendrites are formed on the surface of the negative electrode sheet due to the non-uniform deposition of metal ions. When this dendrite grows to a certain extent, it breaks through the separator and continues to grow in the longitudinal direction of the dendrite to contact the positive electrode sheet, thereby electrically connecting the positive electrode and the negative electrode in the battery, resulting in an internal short circuit, and as a result, the safety performance of the battery decreases.

[0037] In view of this, the present application provides an electrode assembly, a battery cell, a battery, and an electric power consumption device capable of improving the safety performance of the battery. Electrode assembly

[0038] The first aspect of the present application provides an electrode assembly including 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 organic coating including organic particles that react with dendrites containing a single metal.

[0039] 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 containing a single metal. During the use of the battery, dendrites containing a single metal may be generated inside the battery. When these dendrites grow to a certain extent, they come into contact with and react with the organic particles in the organic coating, generating gas. As a result, the probability of a short circuit inside the battery due to the electrical connection between the positive electrode sheet and the negative electrode sheet is reduced, and at the same time, the pressure inside the battery rises, breaking 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.

[0040] In some embodiments of the present application, the organic particles contain a reactive group that reacts with dendrites containing a single sodium metal. The reactive group can contribute to a rapid reaction with dendrites containing a single sodium metal, and further effectively reduce the occurrence of internal short circuits in the battery and the risk of battery explosion caused by the electrical connection between the positive and negative electrodes by dendrites, improving the safety performance of the battery.

[0041] In some embodiments 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 groups are likely to react with dendrites containing a single sodium metal, and can further effectively reduce the electrical connection between the positive and negative electrodes by the above dendrites, further improving the safety performance of the battery.

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

[0043] a. Start the optical bench, printer, and computer in this order, and wait for 3 minutes for the optical bench to reach a stable state after startup. b. Select the necessary operating software by clicking "Start", "All Programs", and "Thermo sciScientific OMNIC" in this order, or by clicking the shortcut on the desktop. c. Self-test of the device: After starting the software, the device will perform a self-test. d. The two indicators in the upper left corner of the host represent the laser and the scan respectively. The laser indicator is always on, and the scan indicator blinks. In case of a malfunction, the laser indicator will turn off. (2) Sample measurement

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

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

[0046] In some embodiments of the present application, the material of the organic particles includes one or more of benzoic acid, benzophenone, indoleacetic acid, phenol, and biphenyl. The above material of the organic particles is likely to react with the dendrite containing the sodium metal alone, and a large amount of gas (such as hydrogen gas) is generated during the reaction with the dendrite, so that the pressure inside the battery rises rapidly, breaking the explosion-proof valve and releasing the pressure early, further improving the safety performance of the battery.

[0047] In an embodiment of the present application, the organic coating may include a coating having an appropriate shape, and in this way, it can contribute to the discharge of gas generated by the reaction between the organic coating and the dendrite and the directional deposition of sodium ions, further improving the safety performance and cycle performance of the battery.

[0048] In some embodiments of the present application, the organic coating includes one or more of a mesh-like organic coating, a dot-like organic coating, and a stripe-like organic coating.

[0049] It should be understood that the organic coating may include one of a mesh-like organic coating, a dot-like organic coating, and a stripe-like organic coating, or may include a combination of two or more types, and is not specifically limited in the embodiments of the present application.

[0050] In the above embodiment, by using a dot-like organic coating and a stripe-like organic coating, the gas generated by the reaction between the organic coating and the dendrite can be guided and discharged, the explosion-proof valve of the battery can be quickly broken through to release the pressure, and the safety performance of the battery can be further improved. The mesh-like organic coating can improve the safety performance of the battery and also contribute to the directional deposition of sodium ions, contributing to the improvement of the cycle performance of the battery.

[0051] In the present application, the shape of the organic coating may also be formed using devices and methods well known in the art. For example, a scanning electron microscope (SEM) can be used to observe the distribution shape of the organic coating on the separator and the positive electrode sheet.

[0052] In some embodiments of the present application, the organic coating includes a dot-shaped organic coating. In the organic coating, the distance between adjacent dot-shaped organic coatings is 0.5 μm to 50 μm. When the distance between adjacent dot-shaped organic coatings is within the above range, the organic coating can react with dendrites to reduce the electrical connection between the positive electrode and the negative electrode caused by dendrites. Further, the gas generated by the reaction between the organic coating and dendrites is discharged from the electrode assembly along the gaps between the dot-shaped organic coatings, and further, the explosion-proof valve of the battery can be quickly broken to release the pressure, thereby further improving the safety performance of the battery.

[0053] In the present application, the distance between adjacent dot-shaped organic coatings has the meaning known in the art and can be measured using devices and methods well-known in the art. For example, a scanning electron microscope (SEM) can be used to measure the distance between adjacent dot-shaped organic coatings.

[0054] In the above embodiments, the distances between adjacent dot-shaped organic coatings may be the same or different, but can be designed according to the difficulty of the process and actual needs.

[0055] In some examples, the distance between adjacent dot-like organic coatings may be 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, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, 21 μm, 22 μm, 23 μm, 24 μm, 25 μm, 26 μm, 27 μm, 28 μm, 29 μm, 30 μm, 31 μm, 32 μm, 33 μm, 34 μm, 35 μm, 36 μm, 37 μm, 38 μm, 39 μm, 40 μm, 41 μm, 42 μm, 43 μm, 44 μm, 45 μm, 46 μm, 47 μm, 48 μm, 49 μm, 50 μm, or a range combined by any two of the above numerical values. For example, the distance range between adjacent dot-like organic coatings may be 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, 20 μm to 30 μm.

[0056] In some embodiments of the present application, the organic coating includes stripe-like organic coatings, and in the organic coating, the distance between adjacent stripe-like organic coatings is 0.5 μm to 50 μm. When the distance between adjacent stripe-like organic coatings is within the above range, the reaction between the organic coating and the dendrite is facilitated, and the gas generated by the reaction between the organic coating and the dendrite is quickly discharged from the electrode assembly, so that the explosion-proof valve of the battery can be broken to release the pressure, thereby further improving the safety performance of the battery.

[0057] In the present application, the distance between adjacent stripe-like organic coatings has the meaning known in the art and can be measured using devices and methods well-known in the art. For example, an electron scanning microscope (SEM) is used to measure the distance between adjacent stripe-like organic coatings.

[0058] In the above embodiments, the distance between adjacent stripe-shaped organic coatings may be the same or different, but it can be designed according to the difficulty of the process and actual needs.

[0059] In some examples, the distance between adjacent stripe-shaped organic coatings is 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, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, 21 μm, 22 μm, 23 μm, 24 μm, 25 μm, 26 μm, 27 μm, 28 μm, 29 μm, 30 μm, 31 μm, 32 μm, 33 μm, 34 μm, 35 μm, 36 μm, 37 μm, 38 μm, 39 μm, 40 μm, 41 μm, 42 μm, 43 μm, 44 μm, 45 μm, 46 μm, 47 μm, 48 μm, 49 μm, 50 μm, or it may be in the range combined by any two of the above numerical values. For example, the range of the distance between adjacent stripe-shaped organic coatings may be 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, 14 μm to 20 μm.

[0060] In some embodiments of the present application, the organic coating includes a mesh-shaped organic coating. In the organic coating, the average pore diameter of the pores included in the mesh-shaped organic coating is 0.5 μm to 50 μm. When the average pore diameter of the pores included in the mesh-shaped organic coating is within the above range, it can improve the safety performance of the battery, contribute to the directional deposition of sodium ions, and contribute to the improvement of the cycle performance of the battery.

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

[0062] In some examples, the average pore diameter of the pores included in the network-like organic coating may be 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, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, 21 μm, 22 μm, 23 μm, 24 μm, 25 μm, 26 μm, 27 μm, 28 μm, 29 μm, 30 μm, 31 μm, 32 μm, 33 μm, 34 μm, 35 μm, 36 μm, 37 μm, 38 μm, 39 μm, 40 μm, 41 μm, 42 μm, 43 μm, 44 μm, 45 μm, 46 μm, 47 μm, 48 μm, 49 μm, 50 μm, or may be in the range of any combination of two of the above numerical values. For example, the range of the average pore diameter of the pores in the network-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, 16 μm to 20 μm.

[0063] In some embodiments of this application, the organic coating is provided on the side facing the separator of the positive electrode sheet. By providing the organic coating on the side facing the separator of the positive electrode sheet, the occurrence of internal short circuit of the battery caused by the dendrite electrically connecting the positive electrode and the negative electrode can be effectively reduced, and the safety performance of the battery can be further improved.

[0064] In some embodiments of the present application, the thickness of the organic coating is 2 μm to 10 μm. When the thickness of the organic coating is within the above range, the safety performance of the battery can be further improved. Moreover, by giving the organic coating an appropriate thickness, a large amount of active material can be filled, contributing to the improvement of the energy density of the battery.

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

[0066] In some examples, the thickness of the organic coating is 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, 3.9 μm, 4 μm, 4.1 μm, 4.2 μm, 4.3 μm, 4.4 μm, 4.5 μm, 4.6 μm, 4.7 μm, 4.8 μm, 4.9 μm, 5 μm, 5.1 μm, 5.2 μm, 5.3 μm, 5.4 μm, 5.5 μm, 5.6 μm, 5.7 μm, 5.8 μm, 5.9 μm, 6 μm, 6.1 μm, 6.2 μm, 6.3 μm, 6.4 μm, 6.5 μm, 6.6 μm, 6.7 μm, 6.8 μm, 6.9 μm, 7 μm, 7.1 μm, 7.2 μm, 7.3 μm, 7.4 μm, 7.5 μm, 7.6 μm, 7.7 μm, 7.8 μm, 7.9 μm, 8 μm, 8.1 μm, 8.2 μm, 8.3 μm, 8.4 μm, 8.5 μm, 8.6 μm, 8.7 μm, 8.8 μm, 8.9 μm, 9 μm, 9.1 μm, 9.2 μm, 9.3 μm, 9.4 μm, 9.5 μm, 9.6 μm, 9.7 μm, 9.8 μm, 9.9 μm, 10 μm, or it may be in the range of any combination of two of the above numerical values, but is not limited thereto. For example, the range of the thickness 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, 4.3 μm to 6.8 μm.

[0067] In some embodiments of the present 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 base film and the second base film in the separator, the mechanical strength of the separator can be enhanced, and furthermore, dendrite penetration of the separator can be suppressed. Also, by providing the organic coating between the first base film and the second base film, the organic particles in the organic coating react with dendrites that have penetrated the first base film or the 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 the present application, the thickness of the organic coating is 2 μm to 10 μm.

[0069] In some embodiments of the present application, the thicknesses of the first base film and the second base film are each independently 5 μm to 20 μm.

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

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

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

[0073] It should be noted that all the related parameters of the above separator and organic coating are single-sided parameters.

[0074] In some embodiments of the present application, the areal density of the organic coating is 1.5 g / m 2 ~4.0 g / m 2 When the areal density of the organic coating is within the above range, the organic coating can effectively reduce the electrical connection between the positive electrode and the negative electrode caused by dendrites.

[0075] In the present application, the above areal density means the areal density of the organic coating on one side, which is a meaning known in the art and can be tested by a method known in the art. For example, it can be tested according to the following steps. The sampled sample is punched into a small circular sheet with an area of S1, its mass is weighed and recorded as M1. Then, the coating on the above weighed sample is removed, the mass of the substrate is weighed and recorded as M0, (1) When there is an organic coating only on one side of the substrate, the areal density of the organic coating on one side = (M1 - M0) / S1, (2) When there are organic coatings on both sides of the substrate, the areal density of the organic coating on one side = (M1 - M0) / S1 / 2.

[0076] In some examples, the areal density of the organic coating is 1.5 g / m 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 , 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 to 3.8 g / m 2 , 1.8 g / m 2 to 2.5 g / m 2 , 2 g / m 2 to 2.3 g / m 2 .

[0077] In some embodiments of the present application, the organic coating further includes an adhesive, and based on the mass of the organic coating, the mass ratio of the adhesive to the organic particles is (1 to 5):(10 to 90). When the adhesive is added, the viscosity of the organic coating increases, and further, the bonding force between the organic coating and the positive electrode sheet, the negative electrode sheet, and the separator becomes stronger, and the peeling of the organic coating can be reduced. In addition, when the mass ratio of the adhesive to the organic particles satisfies the above relationship, the organic coating can react with dendrites to reduce dendrites while maintaining good viscosity, thereby further improving the safety performance of the battery.

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

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

[0080] In some embodiments of the present application, the mass content of the organic particles in the organic coating is 80% to 90%. When the mass content of the organic particles in the organic coating is within the above range, the organic coating can react with more metal monomers, further reducing the possibility that the positive electrode and the negative electrode are electrically connected by dendrites, thereby more effectively improving the safety performance of the battery.

[0081] In some embodiments of the present 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 the present 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 adopted.

[0082] In some embodiments of the present application, the positive electrode active material may include one or more of sodium transition metal oxides, polyanion-type compounds, and Prussian blue-based compounds. In some other embodiments of the present application, some other known materials that can be used as the positive electrode active material of the sodium-ion battery may also be used.

[0083] In some examples, the transition metal in the sodium transition metal oxide may include one or more of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr, and Ce. For example, when the sodium transition metal oxide is Na x MO2, M may be one or more of Ti, V, Mn, Co, Ni, Fe, Cr, and Cu, and 0 < x ≦ 1.

[0084] In some other examples, the polyanion-type compound may be a group of compounds containing sodium ions, transition metal ions, and tetrahedral (YO4) n- anion 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 represents the valence of (YO4) n- .

[0085] The polyanion-type compound may be a group of compounds containing sodium ions, transition metal ions, tetrahedral (YO4) n- anion 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, n represents the valence of (YO4) n- , and the halogen may include one or more of F, Cl, and Br.

[0086] In some specific embodiments, the polyanion-type compound may include one or more of NaFePO4, Na3V2(PO4)3, NaM’PO4F (M’ includes one or more of V, Fe, Mn, and Ni), and Na3(VOy)2(PO4)2F 3-2y (where 0 ≦ y ≦ 1).

[0087] In some examples, the Prussian blue-based compound may be a group of compounds having sodium ions, transition metal ions, and cyanur ions (CN - ). The transition metal may be at least one of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr, and Ce. The Prussian blue-based compound is, for example, Na a Me b Me’ c (CN)6, where Me and Me’ each independently include one or more of Ni, Cu, Fe, Mn, Co, and Zn, and 0 < a ≦ 2, 0 < b < 1, 0 < c < 1.

[0088] In some embodiments of the present application, the positive electrode active material layer may further include a conductive agent and an adhesive. In the embodiments of the present application, the types of the conductive agent and the adhesive included 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, ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers, but is not limited thereto. The adhesive may be one or more of styrene-butadiene rubber (SBR), aqueous acrylic resin, carboxymethyl cellulose (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 thereto.

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

[0091] In an embodiment of the present application, the positive electrode active material, the conductive agent, and the adhesive are sufficiently stirred and mixed in an appropriate amount of N-methylpyrrolidone (NMP) at a certain mass ratio to form a uniform positive electrode slurry, and the positive electrode slurry is applied to the surface of the aluminum foil, which is the positive electrode current collector, and dried, cold-pressed, and die-cut to obtain a positive electrode sheet.

[0092] In some embodiments of the present application, the negative electrode sheet includes a negative electrode current collector. In some examples, the negative electrode current collector may be made of a material having electron conductivity. Exemplarily, the material of the negative electrode current collector may be a copper foil, a nickel foil, a stainless steel foil, or the like.

[0093] In some embodiments of the present application, the negative electrode sheet may be provided on the negative electrode current collector side and further include a negative electrode active material layer containing a negative electrode active material. However, the type of the negative electrode active material is not particularly limited and can be selected by those skilled in the art according to actual needs. For example, the negative electrode active material may include one or more of a carbon material, an alloy material, a transition metal oxide, a transition metal sulfide, a phosphorus-based material, and a titanate material. 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 natural graphite, artificial graphite, mesophase carbon microspheres (MCMB), hard carbon, and soft carbon. The alloy material may include one or more of alloy materials combined with a plurality of elements among Si, Ge, Sn, Pb, and Sb. The chemical formula of the transition metal oxide is, for example, M 1 u O v where M 1 may be one or more selected from Fe, Co, Ni, Cu, Mn, Sn, Mo, Sb, and V, au = 2v, and a is the valence of M 1 . The chemical formula of the transition metal sulfide is, for example, M 2 i S j where M 2 may include one or more of Fe, Co, Ni, Cu, Mn, Sn, Mo, Sb, and V, bi = 2j, and b is the valence of M 2 . The phosphorus-based material may include one or more of red phosphorus, white phosphorus, and black phosphorus. The titanate material may include one or more of Na2Ti3O7, Na2Ti6O 13 , Na4Ti5O 12 , Li4Ti5O 12 , and NaTi2(PO4)3.

[0095] In some embodiments of the present application, the negative electrode active material layer may further include a conductive agent and an adhesive. In the embodiments of the present application, the types of the conductive agent and the 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 thereto. The adhesive may be one or more of styrene-butadiene rubber (SBR), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyvinyl butyral (PVB), aqueous acrylic resin, and carboxymethyl cellulose (CMC), but is not limited thereto.

[0097] In the embodiments of the present application, the negative electrode active material, the conductive agent, and the adhesive are mixed in a certain mass ratio, and sufficiently stirred with an appropriate amount of deionized water to form a uniform negative electrode slurry. The negative electrode slurry is applied to the surface of the negative electrode current collector, dried, cold pressed, and die cut to obtain a negative electrode sheet.

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

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

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

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

[0102] In some embodiments of the present application, the molar concentration of the electrolyte sodium salt in the electrolyte solution is 0.5 mol / L to 3 mol / L, and the electrolyte sodium salt may include one or more of sodium hexafluorophosphate, sodium tetrafluoroborate, sodium bis(trifluoromethylsulfonyl)amide, sodium bis(fluorosulfonyl)amide, and sodium bis(oxalato)borate.

[0103] In some embodiments of the present application, the electrolyte solution may optionally further include an additive. For example, the additive may include a film-forming additive for the negative electrode, a film-forming additive for the positive electrode, or an additive that can improve any performance of the battery cell, such as the overcharge performance, high-temperature performance, or low-temperature output performance of the battery cell.

[0104] In some embodiments of the present application, the battery cell may further include an outer packaging structure. The outer packaging structure can be used to package the above electrode assembly and electrolyte solution.

[0105] In some embodiments of the present application, the outer packaging structure of the battery cell may be a hard case such as a hard plastic case, an aluminum case, or a steel case. The outer packaging structure of the battery cell may also be, for example, a soft pack in the form of a bag-shaped soft pack. The material of the soft bag may be plastic, for example, 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 arbitrary shape. FIG. 1 shows a rectangular-structured battery cell 5 as an example.

[0107] In some embodiments of the present application, as shown in FIG. 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 an accommodation cavity is formed by enclosing the bottom plate and the side plates. The housing 51 has an opening communicating with the accommodation cavity, and the cover plate 53 covers the opening so as to seal the accommodation cavity. Further, an explosion-proof valve is provided on the cover plate 53. When the internal pressure of the housing reaches a predetermined value, the gas pressure breaks the explosion-proof valve, causing the explosion-proof valve to open and discharge the gas, thereby avoiding the explosion of the battery cell. The positive electrode sheet, the negative electrode sheet, and the separator can form an electrode assembly 52 through a winding process and / or a lamination process. The electrode assembly 52 is packaged in the accommodation cavity. The electrolytic solution is impregnated in the electrode assembly 52. The number of electrode units 52 included in the battery cell 5 may be one or more and can be increased or decreased according to needs.

[0108] The manufacturing method of the battery cell of the present application is a known method. In some embodiments of the present application, the positive electrode sheet, the separator, the negative electrode sheet, and the electrolytic solution can be assembled to form a battery cell. For example, a positive electrode sheet, a separator, and a negative electrode sheet are formed into an electrode assembly through a winding process and / or a lamination process, the electrode assembly is placed in the exterior structure, the electrolytic solution is injected after drying, and processes such as vacuum packaging, standing, formation, and shaping are performed to obtain a battery cell. Battery

[0109] The third aspect of the present application provides a battery including the battery cell according to the second aspect of the present application.

[0110] In an embodiment of the present application, in order to meet different power requirements, a battery may include a plurality of battery cells, and a battery cell refers to the minimum unit that constitutes a battery module or a battery pack. The plurality of battery cells are connected in series and / or in parallel via electrode terminals and can be applied to various applications. The battery according to the embodiment of the present application includes a battery module or a battery pack. Here, the plurality of battery cells can be connected in series, in parallel, or in a combination of series and parallel, and the combination of series and parallel means combining series connection and parallel connection. In an embodiment of the present application, the plurality of battery cells may directly assemble a battery pack, or may first assemble a battery module and then assemble a battery pack with the battery module.

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

[0112] FIG. 3 is a schematic configuration diagram of a battery module as an example. As shown in FIG. 3, in the battery module 4, a plurality of battery cells 5 may be sequentially arranged along the longitudinal direction of the battery module 4. Of course, they may be arranged in any other manner. Further, the plurality of battery cells 5 may be fixed by a fastener.

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

[0114] In some embodiments of the present application, the above battery module may be assembled as a battery pack, and the number of battery modules included in the battery pack can be increased or decreased according to the application and capacity of the battery pack.

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

[0116] A fourth aspect of the present application provides a power consumption device including one or more of a battery cell, a battery module, or a battery pack according to the second aspect of the present application. The battery cell, battery module, or battery pack may be used as a power source of the power consumption device or as an energy storage unit of the power consumption device.

[0117] In the present application, the power consumption device may be, but is not limited to, a mobile phone, a tablet computer, a notebook computer, an electric toy, an electric tool, a battery-powered vehicle, an electric vehicle, a ship, an aircraft, an energy storage system, etc. However, the electric toy may be a stationary or mobile electric toy, and may include, for example, a game machine, an electric vehicle toy, an electric ship toy, and an electric airplane toy, and the spacecraft may include an airplane, a rocket, a space shuttle, and a spaceship.

[0118] Further, the power consumption device may select a battery cell, a battery module, or a battery pack according to its usage needs.

[0119] FIG. 6 is a schematic configuration diagram of a power consumption device as an example. The power consumption device is a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or the like. In order to meet the requirements for high output and high energy density of the power consumption device, a battery pack or a battery module can be used.

[0120] The following examples are to explain the content disclosed in the present application in more detail. It is obvious to those skilled in the art that various modifications and changes are possible within the scope of the content disclosed in the present application. Therefore, these examples are merely illustrative for the purpose of explanation. All reagents used in the examples may be commercially available, synthesized according to conventional methods, and may be used as they are without further treatment. All equipment used in the examples is commercially available. Example 1

[0121] Manufacture of the positive electrode sheet

[0122] NaFePO4 as the positive electrode active material, acetylene black as the conductive agent, and carboxymethyl cellulose as the binder are stirred and mixed well in an appropriate amount of N-methylpyrrolidone (NMP) at a mass ratio of 95:2:3 to form a uniform positive electrode slurry. The positive electrode slurry is applied to the surface of an aluminum foil which is the positive electrode current collector, followed by drying, cold pressing, and die cutting to obtain a positive electrode sheet. Manufacture of the negative electrode sheet

[0123] Artificial graphite as the negative electrode active material, acetylene black as the conductive agent, and carboxymethyl cellulose as the binder are mixed at a mass ratio of 94:5:1 and stirred well with an appropriate amount of deionized water to form a uniform negative electrode slurry. The negative electrode slurry is applied to the surface of a copper foil which is the negative electrode current collector, followed by drying, cold pressing, and die cutting to obtain a negative electrode sheet. Separator

[0124] A two-layer polyethylene film with a thickness of 10 μm each is used. Manufacture of the organic coating

[0125] Biphenyl organic particles and carboxymethyl cellulose as the binder are stirred and mixed at a mass ratio of 7:1, and then an organic coating slurry is prepared. Then, the organic coating slurry is applied between the two-layer polyethylene films, dried, and after that, it has a thickness of 4 μm and a surface density of 2.0 g / m 2An organic coating is obtained. Manufacture of electrolyte

[0126] In a glove box filled with argon gas with a water content of less than 1 ppm, diethylene glycol dimethyl ether and tetrahydrofuran are mixed at a mass ratio of 1:3, and sodium hexafluorophosphate (NaPF6) with a concentration of 1.0 mol / L is added and stirred uniformly, and then an electrolyte is obtained. Manufacture of sodium-ion secondary battery

[0127] An electrode assembly is formed by a winding process and / or a lamination process for the positive electrode sheet, separator, and negative electrode sheet, and the electrode assembly is placed in an outer packaging structure. After drying, an electrolyte is injected, and then processes such as vacuum packaging, standing, formation, and shaping are performed to obtain a sodium-ion secondary battery. Examples 2 to 10

[0128] It is similar to the manufacturing method of Example 1, and the difference lies in the components and their contents of the organic coating. Comparative Example 1

[0129] It is similar to the manufacturing method of Example 1, and the difference is that the electrode assembly does not contain an organic coating. Examples 11 to 18

[0130] It is similar to the manufacturing method of Example 1, and the difference lies in the thickness and surface density of the organic coating. Test part (1) Gas generation rate test

[0131] The test method is After baking the assembled battery, injecting the electrolyte, then sealing the liquid injection hole of the battery, and activating it at room temperature, welding a metal band to the positive electrode sheet and the negative electrode sheet of the battery to obtain an activated battery, where the liquid injection hole of the battery is sealed with an OPP beige-colored tape masking tape, an aluminum band is welded to the positive electrode sheet by an ultrasonic welder, and a nickel band is welded to the negative electrode sheet by an internal resistance electric welder. Fixing the activated battery to a jig and connecting the metal bands of the positive electrode sheet and the negative electrode sheet to the positive and negative electrodes of the charge and discharge equipment respectively with leads, where the leads are 2.5 mm 2 copper wires, a crocodile clip is welded to one end connected to the metal band, the charge and discharge equipment is a lithium battery formation test cabinet, and the charge and discharge equipment is installed in a dry factory with a dew point of 5°C or less, a humidity of 20%RH or less, and a temperature of 28°C or less. Turn on the power, pre-charge the activated battery, and record the time and the value of the digital display pressure gauge when the explosion-proof valve breaks before and during charging. Based on the values of the digital display pressure gauge recorded before and after charging, calculate the time t and pressure P required for the explosion-proof valve to break, calculate the volume V of the gas based on PV=nRT, and further calculate the gas generation rate based on V / t, where the threshold value when the explosion-proof valve breaks is 0.65 MPa.

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

[0133]

Table 1

[0134] According to Table 1, when comparing the test structures of Examples 1 to 10 and Comparative Example 1, in the electrode assembly according to the present 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. Since the organic coating contains organic particles that react with dendrites containing a single metal, when the battery is in use, dendrites containing a single metal may be generated inside the battery. However, when this dendrite grows to a certain extent, it contacts and reacts with the organic particles in the organic coating to generate gas. As a result, the probability of short circuit inside the battery due to electrical connection between the positive electrode sheet and the negative electrode sheet decreases, and the pressure inside the battery increases to break the explosion-proof valve of the battery to release the pressure. Therefore, it can be seen that 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 of the organic coating in Examples 11 to 18 respectively.

[0136]

Table 2

[0137] From Table 2, it can be seen that when the thickness and surface density of the organic coating are within appropriate ranges respectively, the gas generation rate due to the reaction between the dendrite and the organic particles contained in the organic coating can be increased. As a result, the probability of short circuit inside the battery due to electrical connection between the positive electrode sheet and the negative electrode sheet decreases, and the pressure inside the battery increases rapidly to break the explosion-proof valve of the battery to release the pressure. Therefore, it can be seen that the risk of the battery exploding is reduced and the safety performance of the battery can be improved.

[0138] Note that each of the above embodiments does not limit the technical solution of the present application, but is merely for illustration purposes. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art can make modifications to the technical solutions described in the above embodiments, or make equivalent substitutions for some or all of the technical features therein, as long as the essence of the corresponding technical solutions does not deviate from the scope of the technical solutions of the embodiments of the present application, all of them should be understood to be included within the scope of the claims and the specification of the present application. In particular, the technical features mentioned in each embodiment can be combined in any way as long as there is no structural contradiction. The present application is not limited to the specific embodiments disclosed in this specification, but includes all technical solutions included in the claims.

Claims

1. a positive electrode sheet, a negative electrode sheet, a separator provided between the positive electrode sheet and the negative electrode sheet, an organic coating provided on a side of the positive electrode sheet facing the separator and / or on one side of the separator, the organic coating containing organic particles that react with dendrites containing a single metal; and an electrode assembly.

2. The organic particles include a reactive group that reacts with dendrites containing a single sodium metal, Optionally, the reactive group includes 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 electrode assembly according to claim 1.

3. The material of the organic particles includes one or more of benzoic acid, benzophenone, indoleacetic acid, phenol, and biphenyl, The electrode assembly according to claim 1 or 2.

4. The organic coating includes one or more of a mesh-like organic coating, a dot-like organic coating, and a stripe-like organic coating, The electrode assembly according to any one of claims 1 to 3.

5. The organic coating is provided on a side of the positive electrode sheet facing the separator, The electrode assembly according to any one of claims 1 to 4.

6. The thickness of the organic coating is 2 μm to 10 μm, The electrode assembly according to any one of claims 1 to 5.

7. 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, The electrode body according to any one of claims 1 to 6.

8. The thickness of the 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 according to claim 7.

9. The areal density of the organic coating is 1.5 g / m ２ to 4.0 g / m ２ is as follows. The electrode assembly according to any one of claims 1 to 8.

10. The organic coating further includes an adhesive, and based on the mass of the organic coating, the mass ratio of the adhesive to the organic particles is (1 to 5):(10 to 90), Optionally, the mass content of the adhesive in the organic coating is 1% to 5%, Optionally, the mass content of the organic particles in the organic coating is 80% to 90%. The electrode assembly according to any one of claims 1 to 9.

11. A battery cell including the electrode assembly according to any one of claims 1 to 10.

12. A battery including the battery cell according to claim 11.

13. An electric power consumption device including the battery according to claim 12.

Images