Battery cell assembly, battery and power utilization device
By providing a reinforcement portion on the separator, the absorption capacity of the electrolyte is enhanced, and the problem that it is difficult to be soaked in the central area of the electrode sheet is solved, which significantly improves the electrochemical performance of the battery.
Patent Information
- Application Number
- CN202420373212.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-28
- Publication Date
- 2025-03-07
- Estimated Expiration
- 2034-02-28
AI Technical Summary
In the existing battery technology, the central area of the electrode sheet is difficult to be fully immersed by the electrolyte, resulting in a reduced lithium-ion performance of the negative electrode and poor circulation performance.
At least one side of the thickness direction of the diaphragm is provided, including a first reinforcement layer and a number of second reinforcement layers connected thereto, to enhance the absorption capacity of the electrolyte and thereby improve the wetting condition of the central area of the electrode sheet.
The infiltration situation in the center of the electrode sheet is significantly improved and the electrochemical performance of the battery is improved.
Smart Images
Figure CN222581215U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of batteries, and in particular to a battery core assembly, a battery and an electrical device. Background Art
[0002] With the development of science and technology, the demand for battery energy density is getting higher and higher. In order to meet this demand, high compaction system and increasing battery size are widely used. However, these methods have an adverse effect on the wettability of the electrolyte, that is, in the battery cell, the pole pieces in the top and bottom areas are easier to be infiltrated by the electrolyte, while the pole pieces in the center area are more difficult to be infiltrated by the electrolyte, especially the pole pieces in the core of the battery cell. This poor infiltration will lead to problems such as lithium deposition at the negative electrode and reduced cycle performance.
[0003] In the prior art, the patent with publication number CN115732747A discloses a lithium-ion battery and its preparation method and application, wherein the two ends of the pole piece have high compaction and the central area has low compaction, and the coating is cancelled in the corresponding central area of the diaphragm, so that the low-compacted central area of the pole piece and the uncoated area in the middle of the diaphragm are interlocked, thereby improving the wettability of the central area of the pole piece. However, since the coating layer has good liquid absorption and liquid retention capabilities, the cancellation of the central coating layer will still cause poor wetting for large-sized battery cells.
[0004] Therefore, it is necessary to provide a method that can effectively achieve good wetting of the central area of the pole piece.
[0005] The above information is presented as background information only to assist with understanding the present disclosure and no determination or admission is made as to whether any of the above may be used as prior art with respect to the present disclosure. Utility Model Content
[0006] The utility model provides a battery core assembly, a battery and an electric device, which can realize good wetting of the central area of a pole piece.
[0007] In order to achieve the above purpose, the utility model provides the following technical solutions:
[0008] In a first aspect, the utility model provides a battery cell assembly, comprising a positive electrode sheet, a negative electrode sheet, and a separator disposed between the positive electrode sheet and the negative electrode sheet, wherein at least one side of the separator in the thickness direction is provided with a reinforcement portion for enhancing electrolyte absorption, and the reinforcement portion comprises:
[0009] A first reinforcement layer is arranged in the middle area in the width direction of the diaphragm and extends along the length direction of the diaphragm;
[0010] A plurality of second reinforcement layers are arranged at intervals along the length direction of the diaphragm, and one end of each of the second reinforcement layers extends to the same side edge in the width direction of the diaphragm, and the other end of each of the second reinforcement layers extends to connect with the first reinforcement layer.
[0011] Furthermore, in the battery cell assembly, the diaphragm includes a main body and a bending portion, the main body is wound together with the positive electrode sheet and the negative electrode sheet to form a battery cell body, and the bending portion is bent toward the center of the bottom end face of the battery cell body and fits the bottom end face of the battery cell body.
[0012] Furthermore, in the battery cell assembly, the size of the bent portion does not exceed 1 / 2 of the thickness of the battery cell body.
[0013] Furthermore, in the battery cell assembly, along the winding direction of the battery cell assembly, the separator includes a starting end and an ending end, and the distance between two adjacent second reinforcement layers gradually increases in the direction from the starting end to the ending end.
[0014] Furthermore, in the battery cell assembly, in the width direction of the diaphragm (2), the width of the first reinforcement layer is within 30% of the width of the diaphragm; and / or in the length direction of the diaphragm (2), the width of the second reinforcement layer (32) is ≤10 mm.
[0015] Furthermore, in the battery core assembly, the first reinforcement layer and the second reinforcement layer are any one of perfluorophenyl azide, aramid, and modified SiO2.
[0016] Furthermore, in the battery cell assembly, a groove is provided at a position of the positive electrode sheet and / or the negative electrode sheet corresponding to the reinforcing portion of the diaphragm, and the reinforcing portion is accommodated in the groove.
[0017] Furthermore, in the battery cell assembly, the reinforcing portion is provided on a side of the diaphragm facing the negative electrode sheet, and the groove is provided on a side of the negative electrode sheet facing the diaphragm.
[0018] In a second aspect, the utility model provides a battery, comprising a housing and a battery cell assembly provided in the first aspect and arranged in the housing.
[0019] In a third aspect, the utility model provides an electrical device, comprising the battery provided in the second aspect.
[0020] Compared with the prior art, the utility model has the following beneficial effects:
[0021] The utility model provides a battery cell assembly, a battery and an electrical device, comprising a positive electrode sheet, a negative electrode sheet and a diaphragm. By arranging a first reinforcement layer for enhancing electrolyte absorption and a plurality of second reinforcement layers connected to the first reinforcement layer on at least one side in the thickness direction of the diaphragm, the wetting condition of the central area of the electrode sheet can be significantly improved, thereby effectively improving the electrochemical performance of the battery.
[0022] The present invention has other characteristics and advantages, which will be apparent from the accompanying drawings and subsequent specific embodiments incorporated herein, or will be described in detail in the accompanying drawings and subsequent specific embodiments incorporated herein, which together are used to explain the specific principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0024] Figure 1 It is a structural schematic diagram of a battery core assembly provided in Embodiment 1 of the present utility model;
[0025] Figure 2 It is a schematic diagram of the structure of the diaphragm provided in the first embodiment of the utility model;
[0026] Figure 3 This is a schematic diagram of the structure in which the bending portion provided in the first embodiment of the utility model is bent at the bottom end surface of the battery cell body;
[0027] Figure 4 It is a schematic diagram of the structure of the negative electrode sheet provided in the first embodiment of the present utility model.
[0028] Reference numerals:
[0029] Positive electrode sheet 1, negative electrode sheet 2, separator 3, reinforcement part 4, groove 5;
[0030] A main body portion 31, a bending portion 32;
[0031] A first reinforcement layer 41, a second reinforcement layer 42;
[0032] A first groove 51 and a second groove 52 . DETAILED DESCRIPTION
[0033] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. In addition, ordinary technicians in this field can know that with the development of technology and the emergence of new scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.
[0034] In the description of the present application, it should be understood that, unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as those commonly understood by those skilled in the art of the present application. In addition, any terminology used is only for the purpose of describing specific embodiments and is not intended to limit the present application.
[0035] In addition, in order to better illustrate the present application, numerous specific details are given in the following specific embodiments. It should be understood by those skilled in the art that the present application can also be implemented without certain specific details. In some examples, methods, means, components and circuits well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present application.
[0036] The technical solution of the utility model is further explained below with reference to the accompanying drawings and through specific implementation methods.
[0037] Embodiment 1
[0038] In view of the above-mentioned defects of existing batteries, the applicant, based on many years of rich practical experience and professional knowledge in the design and manufacture of such products, and in conjunction with the application of theory, actively conducts research and innovation in the hope of creating a technology that can solve the defects in the existing technology and make the battery more practical. After continuous research and design, and repeated trial production and improvement, the present utility model with real practical value was finally created.
[0039] Please refer to Figure 1-3 The present invention provides a battery cell assembly, including a positive electrode sheet 1, a negative electrode sheet 2, and a separator 3 disposed between the positive electrode sheet 1 and the negative electrode sheet 2. Figure 1 As shown;
[0040] At least one side of the diaphragm 3 in the thickness direction is provided with a reinforcement portion 4 for enhancing electrolyte absorption, such as Figure 2 As shown, the reinforcement portion 4 includes:
[0041] The first reinforcement layer 41 is arranged in the width direction of the diaphragm 3 (i.e. Figure 2The middle area on the W direction) and extending along the length direction of the diaphragm 3;
[0042] A plurality of second reinforcement layers 42 are provided along the length direction of the diaphragm 3 (i.e. Figure 2 The second reinforcement layers 42 are arranged at intervals in the L direction, and one end of each second reinforcement layer 42 extends to the same side edge in the width direction of the diaphragm 3, and the other end of each second reinforcement layer 42 extends to be connected to the first reinforcement layer 41.
[0043] It should be noted that during the injection process, the two end regions (i.e., the top and bottom) of the electrode (i.e., the positive electrode 1 and the negative electrode 2) can be in direct contact with the electrolyte and the infiltration is relatively good, and generally no additional improvement is required. However, the central region of the electrode cannot be in direct contact with the electrolyte and can only be slowly infiltrated by the electrode and the diaphragm 3 under the action of capillary pressure, so that the infiltration effect of the central region of the electrode is relatively poor. In order to solve this problem, this embodiment provides a reinforcement part 4 on at least one side in the thickness direction of the diaphragm 3 without changing the original coating layer of the diaphragm 3. The reinforcement part 4 has a strong electrolyte absorption capacity, which is beneficial to enhance the penetration of the electrolyte into the central region of the electrode, thereby significantly improving the infiltration of the central region of the electrode, and effectively improving the electrochemical performance of the battery.
[0044] It should be further explained that, when the positive electrode sheet 1, the separator 3 and the negative electrode sheet 2 are stacked and wound in sequence to form a battery cell body, the portion of the second reinforcement layer 42 corresponding to the lower portion of the battery cell body (including the bottom and possibly other portions near the bottom) is convenient for absorbing the electrolyte located in the lower portion of the battery cell body and permeating upward until it permeates into the first reinforcement layer 41, and the first reinforcement layer 41 continues to permeate the electrolyte in the central area of the electrode sheet.
[0045] Please refer again Figure 2 In this embodiment, along the winding direction of the battery cell assembly, the diaphragm 3 includes a starting end and an end, and the distance between two adjacent second reinforcement layers 42 gradually increases in the direction from the starting end to the end, that is, the second reinforcement layers 42 are arranged in a dense to sparse manner as a whole. When winding, the starting end of the diaphragm 3 where the second reinforcement layers 42 are densely arranged is wound first, so as to finally be wound into a battery cell.
[0046] It should be noted that after winding, the core of the battery body is relatively compact and relatively difficult for the electrolyte to infiltrate. The outside of the battery body is easy to infiltrate due to the small tension. Therefore, for the core area of the battery body, the interval between two adjacent second reinforcement layers 42 needs to be set smaller. As the electrode sheet infiltration becomes easier from the core to the outside, the interval between two adjacent second reinforcement layers 42 can be set to gradually increase, and even the outside does not need to be provided with a second reinforcement layer 42. Specifically, it can be determined according to the electrolyte infiltration in the actual battery body structure, thereby determining the interval size and density rule between two adjacent second reinforcement layers 42.
[0047] In this embodiment, in the width direction of the diaphragm 3 , the width of the first reinforcement layer 41 is within 30% of the width of the diaphragm 3 ;
[0048] It should be noted that the first reinforcement layer 41 is located in the middle area in the width direction of the diaphragm 3, and the middle area in the width direction of the diaphragm 3 is exactly the area of poor infiltration. The width of this area is generally within 30% of the width of the diaphragm 3. Therefore, in the width direction of the diaphragm 3, the width of the first reinforcement layer 41 also needs to correspond to within 30% of the width of the diaphragm 3.
[0049] And / or, in the length direction of the diaphragm 3 , the width of the second reinforcement layer 42 is ≤10 mm.
[0050] It should be noted that, in the case where the second reinforcement layer 42 is provided in the length direction of the diaphragm 3, after optimization, the width of the second reinforcement layer 42 is limited to within 10 mm. Such a design not only ensures the purpose of wetting the central area of the pole piece, but also helps to improve the strength and stability of the diaphragm, especially the performance in the length direction.
[0051] In this embodiment, the material selection of the reinforcement part 4 has great flexibility and can be optimized according to specific application requirements to achieve the best performance.
[0052] Exemplarily, the reinforcing part 4 (ie, including the first reinforcing layer 41 and the second reinforcing layer 42 ) is any one of perfluorophenyl azide, aramid, and modified SiO 2 .
[0053] It is understandable that the reinforcing part 4 is not limited to the above materials, and any coating material with strong liquid absorption ability can be considered. This embodiment is only an example and does not constitute a limitation on the material selection of the reinforcing part 4.
[0054] In addition, the reinforcing part 4 can also be any two or more combinations of perfluorophenyl azide compounds, aramid, and modified SiO2. This combination can make full use of the advantages of various materials to achieve better performance effects.
[0055] Please refer again Figure 2-3 In this embodiment, the diaphragm 3 includes a main body 31 and a bending portion 32. The main body 31 is wound together with the positive electrode sheet 1 and the negative electrode sheet 2 to form a battery cell body. The bending portion 32 is bent toward the center of the bottom end surface of the battery cell body and fits the bottom end surface of the battery cell body.
[0056] It should be noted that the edge of one side of the diaphragm 3 on which the second reinforcement layer 42 is provided in the width direction needs to be further extended on the basis of the original overhang design to exceed the edge of the pole piece, and finally be bent at the bottom end surface of the wound battery body to form a bent portion 32.
[0057] This embodiment further optimizes the layout and direction of the bent portion 32. When the bent portions 32 of multiple diaphragms 3 are bent at the bottom end surface of the battery body, they form a stacked structure. This design not only enhances the mechanical stability of the battery cell, but also improves its space utilization.
[0058] The bending direction of each bend portion 32 is toward the center of the bottom end face of the battery cell body. This design makes the overall structure gather from the outside to the inside, presenting a compact and orderly shape. In addition, due to the gravity of the battery cell body, each bend portion 32 will fit the bottom end face of the battery cell body, and each bend portion 32 can fit tightly together. This layout is beneficial to the battery cell body during the liquid injection process. Even if the electrolyte is gathered at the bottom of the battery cell due to the vacuum and gravity, it is still in continuous contact with the electrolyte due to the existence of the bend portion 32, thereby enhancing the absorption of the electrolyte and quickly conducting the infiltrated electrolyte to the central area of the electrode 1.
[0059] In this embodiment, the size of the bent portion 32 does not exceed 1 / 2 of the thickness of the battery cell body.
[0060] It should be noted that the size of the bent portion 32 has an important impact on the performance and safety of the battery cell. In order to ensure the stability and reliability of the battery cell, this size must be strictly controlled. In this embodiment, the size is limited to within 1 / 2 of the thickness of the battery cell, which can ensure continuous enhancement of electrolyte absorption on the one hand, and on the other hand, it can ensure that the performance of the battery cell is not negatively affected.
[0061] Please refer to Figure 4 In this embodiment, a groove 5 is provided in the positive electrode sheet 1 and / or the negative electrode sheet 2 at a position corresponding to the reinforcing portion 4 of the diaphragm 3, and the reinforcing portion 4 is accommodated in the groove 5. Figure 4 The negative electrode sheet 2 is taken as an example.
[0062] It should be noted that, since the addition of the reinforcement part 4 on the diaphragm 3 will occupy space on the thickness of the battery body, it may affect the energy density of the battery body. In order to avoid this situation, the present embodiment is designed to provide a groove 5 on the pole piece (positive pole piece 1 and / or negative pole piece 2). The main purpose of the design of the groove 5 is to accommodate the reinforcement part 4, so that the groove 5 can fill the space occupied by the reinforcement part 4. In this way, the space can be effectively utilized, and the increase in the thickness of the battery body due to the addition of the reinforcement part 4 can be avoided, thereby affecting the energy density of the battery.
[0063] It is understandable that in order to cooperate with the reinforcing portion 4, the design of the groove 5 needs to be further optimized to better cooperate with the function of the reinforcing portion 4, that is, the groove 5 also needs to include a first groove 51 and a plurality of second grooves 52, such as Figure 4 As shown, such a layout can better adapt to the structural characteristics of the reinforcement part 4.
[0064] The first groove 51 is arranged to match the first reinforcement layer 41 . This matching design ensures that the first reinforcement layer 41 can be completely accommodated in the groove 51 .
[0065] The arrangement of the plurality of second grooves 52 matches the arrangement of the plurality of second reinforcement layers 42 . Through this matching design, the second reinforcement layers 42 can be accurately placed in the second grooves 52 .
[0066] It should be noted that, in order to achieve this matching design, corresponding groove processing needs to be performed on the positive electrode sheet 1 and / or the negative electrode sheet 2. Through the precise groove processing, it can be ensured that the first groove 51 matches the first reinforcement layer 41, and the second groove 52 matches the second reinforcement layer 42.
[0067] It is understandable that in this embodiment, considering that the wetting of the negative electrode is usually poor, the negative electrode is more susceptible to lithium deposition than the positive electrode. Therefore, in this embodiment, there is no need to set the groove 5 on both the positive and negative electrodes, but only on the negative electrode sheet 2.
[0068] Specifically, the reinforcement part 4 is arranged on the side of the diaphragm 3 facing the negative electrode sheet 2, and the groove 5 is arranged on the side of the negative electrode sheet 2 facing the diaphragm 3. Such a layout ensures that the reinforcement part 4 on the diaphragm 3 can be accurately accommodated by the groove 5 on the negative electrode sheet 2, thereby optimizing the cooperation between the diaphragm 3 and the negative electrode sheet 2, and improving the wetting effect of the central area of the negative electrode sheet 2 by the reinforcement part 4 on the diaphragm 3.
[0069] In this embodiment, the groove 5 can be formed by laser cutting or solvent cleaning.
[0070] It should be noted that laser cutting is a high-precision processing method that uses a high-energy laser beam to cut, punch or engrave materials. For the processing of groove 5, laser cutting can achieve high-precision shape and size control while avoiding thermal damage or residual stress to the material. By adjusting the laser parameters and cutting path, the various sizes and edge qualities of the grooves can be accurately controlled to meet different application requirements. This grooving processing technology is mature and has been widely used in various battery manufacturing processes.
[0071] Solvent cleaning is a commonly used surface treatment method that uses the interaction between a specific chemical solvent and the material surface to achieve the purpose of cleaning, decontamination, and removal of impurities. When the solvent contacts the surface of the pole piece 1, the solvent molecules interact with the impurity molecules on the surface of the groove 5, causing the impurity molecules to be dissolved and removed. Solvent cleaning has the advantages of simple operation and low cost, so it has been widely used in industrial production.
[0072] In practical applications, the two processing methods of laser cutting and solvent cleaning can be arbitrarily selected to process the groove 5 to obtain a high-quality groove 5 .
[0073] Although the terms such as positive electrode sheet, negative electrode sheet, diaphragm, reinforcement part, groove, etc. are used more frequently in this application, the possibility of using other terms is not excluded. These terms are used only to more conveniently describe and explain the essence of the utility model; interpreting them as any additional restrictions is contrary to the spirit of the utility model.
[0074] The utility model provides a battery cell, comprising a positive electrode sheet, a negative electrode sheet and a diaphragm. By arranging a first reinforcement layer for enhancing electrolyte absorption and a plurality of second reinforcement layers connected to the first reinforcement layer on at least one side in the thickness direction of the diaphragm, the wetting condition of the central area of the electrode sheet can be significantly improved, thereby effectively improving the electrochemical performance of the battery.
[0075] Embodiment 2
[0076] The utility model provides a battery, comprising a shell and a battery core as provided in the above-mentioned embodiment 1, wherein the battery core is accommodated in the shell.
[0077] It is understandable that the battery also includes other component designs in addition to the above-mentioned contents, such as electrolyte, top cover and bottom plate, etc. The specific function of these component designs is to ensure the normal operation of various functions of the battery. In view of the fact that these component designs have been implemented in many existing technologies and are not the focus of the design of this embodiment, they will not be elaborated in depth here.
[0078] The battery provided in this embodiment has good electrode wettability and electrochemical performance due to the battery cell provided in the first embodiment.
[0079] Embodiment 3
[0080] The utility model provides an electric device, comprising the battery provided in the above-mentioned second embodiment.
[0081] It should be noted that the electrical device may be, for example, an electronic device, an electric vehicle or a power storage system. Among them, the electronic device may be, for example, various computers, mobile phones, display screens and other equipment that use batteries as driving power sources. The electric vehicle may be, for example, an electric car, an electric tricycle, an electric bicycle, etc. that use batteries as driving power sources. The power storage system may be, for example, a power storage system that uses batteries as power storage sources.
[0082] The battery refers to a battery cell. In this embodiment, the power-consuming device may be powered directly by the battery cell, or by a battery pack formed by connecting a plurality of battery cells in parallel, in series or in a mixed manner.
[0083] The electric device provided in this embodiment has the battery provided in the above-mentioned second embodiment, so the electrode wettability and electrochemical performance of the battery of the electric device are both good.
[0084] It is understandable that the electrical device includes not only a battery for providing electrical energy, but also an object for receiving electrical energy, namely, the electrical subject. The battery is connected to the electrical subject, and the electrical subject can realize the set functions under the drive of electrical energy.
[0085] In summary, after reading this detailed disclosure, it will be apparent to those skilled in the art that the aforementioned detailed disclosure may be presented only by way of example and may not be restrictive. Although not explicitly stated herein, it will be appreciated by those skilled in the art that this application is intended to encompass various reasonable changes, improvements and modifications to the embodiments. These changes, improvements and modifications are intended to be proposed by this application and are within the spirit and scope of the exemplary embodiments of this application.
[0086] In addition, certain terms in this application have been used to describe embodiments of the present application. For example, "one embodiment", "embodiment" and / or "some embodiments" mean that a particular feature, structure or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. Therefore, it can be emphasized and should be understood that two or more references to "embodiment" or "one embodiment" or "alternative embodiment" in various parts of this specification do not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics may be appropriately combined in one or more embodiments of the present application.
[0087] It should be understood that in the foregoing description of the embodiments of the present application, in order to help understand a feature and for the purpose of simplifying the present application, the present application combines various features in a single embodiment, drawing or its description. However, this does not mean that the combination of these features is necessary. When reading the present application, it is entirely possible for a person skilled in the art to extract some of the features and understand them as separate embodiments. In other words, the embodiments in the present application can also be understood as the integration of multiple secondary embodiments. This is also true when the content of each secondary embodiment is less than all the features of a single aforementioned disclosed embodiment.
[0088] Finally, it should be understood that the embodiments of the application disclosed herein are explanations of the principles of the embodiments of the present application. Other modified embodiments are also within the scope of the present application. Therefore, the embodiments disclosed in the present application are merely examples and not limitations. Those skilled in the art can adopt alternative configurations according to the embodiments in the present application to implement the application in the present application. Therefore, the embodiments of the present application are not limited to the embodiments accurately described in the application.
Claims
1. A battery cell assembly, comprising a positive electrode sheet (1), a negative electrode sheet (2), and a separator (3) arranged between the positive electrode sheet (1) and the negative electrode sheet (2), characterized in that: At least one side of the diaphragm (3) in the thickness direction is provided with a reinforcement part (4) for enhancing electrolyte absorption, and the reinforcement part (4) comprises: A first reinforcement layer (41) is arranged in a middle region in the width direction of the diaphragm (3) and extends along the length direction of the diaphragm (3); A plurality of second reinforcement layers (42) are arranged at intervals along the length direction of the diaphragm (3), and one end of each of the second reinforcement layers (42) extends to the same side edge in the width direction of the diaphragm (3), and the other end of each of the second reinforcement layers (42) extends to connect with the first reinforcement layer (41).
2. The battery cell assembly according to claim 1, characterized in that: The diaphragm (3) comprises a main body (31) and a bent portion (32); the main body (31) is wound together with the positive electrode sheet (1) and the negative electrode sheet (2) to form a battery cell body; the bent portion (32) is bent toward the center of the bottom end face of the battery cell body and fits the bottom end face of the battery cell body.
3. The battery cell assembly according to claim 2, characterized in that: The size of the bent portion (32) does not exceed 1 / 2 of the thickness of the battery cell body.
4. The battery core assembly according to claim 1, characterized in that: Along the winding direction of the battery cell assembly, the diaphragm (3) comprises a starting end and an ending end, and the distance between two adjacent second reinforcement layers (42) gradually increases in a direction from the starting end to the ending end.
5. The battery core assembly according to claim 1, characterized in that: In the width direction of the diaphragm (3), the width of the first reinforcement layer (41) is within 30% of the width of the diaphragm (3); and / or in the length direction of the diaphragm (3), the width of the second reinforcement layer (42) is ≤10 mm.
6. The battery core assembly according to claim 1, characterized in that: The first reinforcement layer (41) and the second reinforcement layer (42) are each any one of perfluorophenyl azide, aramid, and modified SiO2.
7. The battery cell assembly according to any one of claims 1 to 6, characterized in that: A groove (5) is provided in the positive electrode sheet (1) and / or the negative electrode sheet (2) at a position corresponding to the reinforcing portion (4) of the diaphragm (3), and the reinforcing portion (4) is accommodated in the groove (5).
8. The battery cell assembly according to claim 7, characterized in that: The reinforcing portion (4) is provided on the side of the diaphragm (3) facing the negative electrode sheet (2), and the groove (5) is provided on the side of the negative electrode sheet (2) facing the diaphragm (3).
9. A battery, characterized in that: The invention comprises a shell and a battery cell assembly as claimed in any one of claims 1 to 8 arranged in the shell.
10. An electrical device, characterized in that: Comprising the battery as claimed in claim 9.
Citation Information
Patent Citations
Lithium ion battery and preparation method and application thereof
CN115732747A