Battery cell pole piece structure, battery cell and battery
By introducing a phase change material layer into the cell pole structure of the lithium-ion battery, the generated heat is absorbed, and the thermal runaway problem of the battery during mechanical abuse or thermal abuse is solved, the safety and stability of the battery are improved, and the mechanical toughness of the battery is enhanced.
Patent Information
- Application Number
- CN202420349748.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-26
- Publication Date
- 2025-02-28
- Estimated Expiration
- 2034-02-26
AI Technical Summary
Existing lithium-ion batteries can easily lead to thermal runaway during mechanical abuse or thermal abuse, reducing the safety of the battery and may cause accidents such as explosions.
A battery cell electrode plate structure is adopted, including a current collector, an active material layer and a phase change material layer. The phase change material layer is arranged in the empty foil area and alternately arranged with the active material layer to absorb heat generated by the electrode plate structure and control the battery cell temperature.
Effectively prevent the battery cell from getting out of control during mechanical abuse or thermal abuse, improve the safety and stability of the battery, and at the same time enhance the toughness at the corners of the battery cell and improve mechanical safety.
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field, and in particular relates to a battery cell pole piece structure, a battery cell and a battery. Background Art
[0002] At present, lithium-ion batteries are composed of components such as positive electrodes, negative electrodes, separators, and electrolytes. The production of battery cells is completed through processes such as slurrying, coating, rolling, slitting, winding, injection, assembly, and formation. The improvement of battery cell energy density can be solved from the perspectives of gram capacity and thickness of each component material. The improvement of energy density of the pole piece can be achieved by introducing high-gram capacity positive electrode materials, increasing positive electrode surface density, and increasing positive electrode compaction. With the continuous updating and development of lithium-ion battery technology, battery cell safety issues are receiving more and more attention.
[0003] However, in the battery cell structure of the prior art, when the battery is mechanically abused or thermally abused, it will cause thermal runaway, thereby reducing the safety of battery use and being prone to accidents such as explosion. Utility Model Content
[0004] The purpose of the utility model is to provide a battery cell pole piece structure to solve the problem of thermal runaway caused by mechanical or thermal abuse of the battery cell in view of the deficiencies in the prior art.
[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:
[0006] A battery cell pole piece structure comprises a current collector, an active material layer and at least one phase change material layer; the active material layer is arranged on at least one side surface of the current collector; at least one empty foil area is provided on the current collector; the phase change material layer is arranged in at least one of the empty foil areas; and the phase change material layer and the active material layer are alternately arranged along the length direction of the current collector.
[0007] Preferably: the empty foil area includes at least one corner empty foil area located at a corner of the battery cell; the variable material layer is provided on the corner empty foil area.
[0008] Preferably, the phase change material layer is one of polystyrene, polyvinyl chloride, polyester, polyamide, polyurethane and polysulfide rubber.
[0009] Preferably, the relationship between the thickness H2 of the active material layer and the thickness H1 of the phase change material layer satisfies: 0
[0010] The utility model also discloses a battery core, comprising the battery core pole piece structure as described above.
[0011] Preferably: the battery cell includes a first pole piece, a second pole piece, and an isolation membrane arranged between the first pole piece and the second pole piece, the first pole piece and the second pole piece have opposite polarities, and the first pole piece and / or the second pole piece are the battery cell pole piece structure as described.
[0012] Preferably: the first pole piece is a positive pole piece, and the first pole piece is a battery cell pole piece structure as described above.
[0013] Preferably: the battery cell is a wound battery cell formed by stacking and winding the first pole piece, the isolation membrane and the second pole piece, the battery cell comprises a straight portion and a corner portion, and the corner empty foil area of the battery cell pole piece structure is located at the corner portion of the battery cell.
[0014] Preferably: the areas of the first pole piece located at the corners are all corner empty foil areas.
[0015] The utility model also discloses a battery, comprising the battery core.
[0016] The beneficial effect of the utility model is that the technical solution absorbs the heat generated by the battery cell pole piece structure during use by using a phase change material layer, thereby effectively controlling the pole piece structure and the temperature of the battery cell, and preventing thermal runaway when the battery cell is mechanically abused or thermally abused, thereby improving the safety and stability of battery use. On the other hand, the phase change material layer of the technical solution is a polymer material and is arranged at the corner of the battery cell, so that the toughness of the pole piece at the corner of the battery cell can be increased, the problem of pole piece fracture at the corner of the battery cell can be improved, and the mechanical safety of the battery cell can be improved. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The following will refer to the attached Figures 1 to 3 To describe the features, advantages and technical effects of exemplary embodiments of the present utility model.
[0018] Figure 1 This is a schematic diagram of the overall structure of a battery cell pole piece structure according to an embodiment of the utility model;
[0019] Figure 2 This is a schematic diagram of the overall structure of a battery cell pole piece structure according to an embodiment of the utility model;
[0020] Figure 3 This is a schematic diagram of the structure of a battery cell according to an embodiment of the utility model;
[0021] Figure 4 The figure is a schematic structural diagram of a battery cell according to an embodiment of the utility model.
[0022] In the figure: 1-current collector; 2-active material layer; 3-phase change material layer; 4-empty foil area; 41-head empty foil area; 42-corner empty foil area; 100-first pole piece; 101-positive pole piece; 200-second pole piece; 201-negative pole piece; 300-isolating film. DETAILED DESCRIPTION
[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.
[0024] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.
[0025] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.
[0026] In the description of the embodiments of the present application, the term "and / or" is merely an association relationship between the related objects of the description of the cell pole piece structure, the cell and the battery, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and multiple situations exist alone. In addition, the character " / " in this article generally indicates that the previous and next related objects are an "or" relationship between a cell pole piece structure, a cell and a battery.
[0027] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).
[0028] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.
[0029] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.
[0030] The following is combined with Figure 1 to Figure 4 The utility model is further described in detail, but it is not intended to limit the utility model.
[0031] like Figure 1 As shown, in one embodiment of the utility model, the battery cell electrode structure includes a current collector 1, an active material layer 2 and at least one phase change material layer 3; the active material layer 2 is arranged on at least one side surface of the current collector 1; at least one empty foil area 4 is provided on the current collector 1; the phase change material layer 3 is arranged in at least one empty foil area 4; and the phase change material layer 3 and the active material layer 2 are alternately arranged along the length direction A of the current collector 1.
[0032] The technical solution of the utility model absorbs the heat generated by the battery cell pole piece structure during use by using a phase change material layer, thereby effectively controlling the pole piece structure and the temperature of the battery cell, preventing thermal runaway when the battery cell is mechanically abused or thermally abused, thereby improving the safety and stability of battery use. On the other hand, the phase change material layer of the technical solution is a polymer material and is arranged at the corner of the battery cell, so that the toughness of the pole piece at the corner of the battery cell can be increased, the problem of pole piece fracture at the corner of the battery cell can be improved, and the mechanical safety of the battery cell can be improved.
[0033] The phase change material layer refers to a material that changes its state and provides latent heat without changing its temperature. The process of changing physical properties is called a phase change process, during which the phase change material absorbs or releases a large amount of latent heat.
[0034] Specifically, in some embodiments, Figure 1 As shown, the empty foil area 4 includes a head empty foil area 41 and at least one corner empty foil area 42 located at the corner of the battery cell; the phase change material layer 3 is provided on the corner empty foil area 42. That is, the active material layer 2 is not coated at the corner of the battery cell structure, and the phase change material layer 3 is coated in the corner empty foil area 42, so as to increase the toughness of the corner, improve the corner fracture problem of the pole piece, and enhance the mechanical safety performance of the battery.
[0035] Specifically, in some embodiments, the initial melting temperature of the phase change material layer 3 is not higher than 150°C, the melting range of the phase change material layer 3 is not greater than 8°C; and the phase change latent heat of the phase change material layer 3 is not less than 240J / g. Wherein, the phase change material layer 3 is one or more of polystyrene, polyvinyl chloride, polyester, polyamide, polyurethane and polysulfide rubber, and the number average molecular weight of these materials is 104-106. The structure has a certain heat absorption performance through the initial melting temperature not higher than 150°C, the melting range not greater than 8°C and the phase change latent heat not less than 240J / g, and can absorb part of the heat when thermal abuse occurs, delay the occurrence of thermal runaway, and improve the thermal safety performance of the battery; at the same time, it can also avoid excessive heat absorption and cause the temperature of the pole piece structure to be too low, thereby further improving the thermal safety performance of the battery.
[0036] Specifically, in some embodiments, Figure 2 As shown, the relationship between the thickness H2 of the active material layer 2 and the thickness H1 of the phase change material layer 3 satisfies: 0
[0037] Specifically, in some embodiments, Figure 2 As shown, the total thickness H1 of the phase change material layer 3 on both sides of the current collector 1 is in the range of 40um≤H1≤150um. When the phase change material layer 3 is applied to the cathode pole piece, the total thickness H1 of the phase change material layer 3 on both sides of the current collector 1 is in the range of 40um≤H1≤140um; when the active material 2 of the cathode is continuously coated, laser cleaning is required in the corner area to obtain a cathode sheet with an empty corner foil. When the phase change material layer 3 is applied to the anode pole piece, the total thickness H1 of the phase change material layer 3 on both sides of the current collector 1 is in the range of 60um≤H1≤150um; when the active material 2 of the anode is continuously coated, laser cleaning is required in the corner area to obtain an anode sheet with an empty corner foil area 42.
[0038] Specifically, in some embodiments, the lengths of the active material layers 2 are equal; the lengths of the phase change material layers 3 are equal or different. By limiting the lengths of the active material layers 2 and the phase change material layers 3, the wound battery cell has good applicability.
[0039] The utility model also provides a battery cell, such as Figure 3 As shown, the battery cell includes a first pole piece 100 and a second pole piece 200 and a separator 300 disposed between the first pole piece 100 and the second pole piece 200. The first pole piece 100 and the second pole piece 200 have opposite polarities, and the first pole piece 100 and / or the second pole piece 200 are the above-mentioned battery cell pole piece structure. The specific structure of the battery cell pole piece structure refers to the above-mentioned embodiment. Since the present battery cell adopts all the technical solutions of all the above-mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be described one by one here.
[0040] Among them, Figure 4 As shown, the first pole piece 100 is a positive pole piece 101; the second pole piece 200 is a negative pole piece 201; the positive pole piece 101 is the above-mentioned battery cell pole piece structure. Further, the battery cell is a wound battery cell formed by stacking and winding the first pole piece 100, the isolation film 300 and the second pole piece 200, and the battery cell includes a straight portion and a corner portion, and the corner empty foil area of the battery cell pole piece structure is located at the corner portion of the battery cell.
[0041] Wherein, the area of the first pole piece 100 located at the corner portion is all the corner empty foil area.
[0042] The utility model also proposes a battery, which includes a battery cell. The specific structure of the battery cell refers to the above embodiment. Since the battery adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.
[0043] Among them, battery refers to a cup, trough or other container or part of a composite container that contains electrolyte solution and metal electrodes to generate current, and is a device that can convert chemical energy into electrical energy; the battery has positive and negative electrodes. With the advancement of science and technology, batteries generally refer to small devices that can generate electrical energy, such as solar cells. The performance parameters of batteries mainly include electromotive force, capacity, specific energy and resistance. Battery principle: In chemical batteries, the direct conversion of chemical energy into electrical energy is the result of spontaneous oxidation, reduction and other chemical reactions inside the battery, which are carried out on the two electrodes respectively. The negative electrode active material is composed of a reducing agent with a relatively negative potential and stable in the electrolyte, such as active metals such as zinc, cadmium, and lead, and hydrogen or hydrocarbons. The positive electrode active material is composed of an oxidizing agent with a relatively positive potential and stable in the electrolyte, such as metal oxides such as manganese dioxide, lead dioxide, and nickel oxide, oxygen or air, halogens and their salts, oxygen-containing acids and their salts, etc. The electrolyte is a material with good ionic conductivity, such as an aqueous solution of acid, alkali, or salt, an organic or inorganic non-aqueous solution, a molten salt, or a solid electrolyte.
[0044] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode includes only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.
[0045] According to the disclosure and teaching of the above description, the technicians in the field of the utility model can also change and modify the above implementation. Therefore, the utility model is not limited to the above specific implementation, and any obvious improvement, replacement or modification made by the technicians in this field on the basis of the utility model belongs to the protection scope of the utility model. In addition, although some specific terms are used in this specification, these terms are only for the convenience of explanation and do not constitute any limitation to the utility model.
Claims
1. A battery cell pole piece structure, characterized in that: The invention comprises a current collector, an active material layer and at least one phase change material layer; the active material layer is arranged on at least one side surface of the current collector; At least one empty foil area is provided on the current collector; the phase change material layer is arranged in at least one of the empty foil areas; and the phase change material layer and the active material layer are alternately arranged along the length direction of the current collector.
2. The battery cell electrode structure according to claim 1, characterized in that: The empty foil area includes at least one corner empty foil area located at a corner of the battery cell; the variable material layer is arranged on the corner empty foil area.
3. The battery cell electrode structure according to claim 1, characterized in that: The phase change material layer is one of polystyrene, polyvinyl chloride, polyester, polyamide, polyurethane and polysulfide rubber.
4. The battery cell electrode structure according to any one of claims 1 to 3, characterized in that: The relationship between the thickness H2 of the active material layer and the thickness H1 of the phase change material layer satisfies: 0<H1≤H2.
5. A battery cell, characterized in that: It comprises a battery cell electrode structure as described in any one of claims 1 to 4 above.
6. The battery cell according to claim 5, characterized in that: The battery cell includes a first pole piece, a second pole piece, and an isolation membrane arranged between the first pole piece and the second pole piece, the first pole piece and the second pole piece have opposite polarities, and the first pole piece and / or the second pole piece is a battery cell pole piece structure as described in any one of claims 1 to 4.
7. The battery cell according to claim 6, characterized in that: The first pole piece is a positive pole piece, and the first pole piece is the battery cell pole piece structure as described in any one of claims 1 to 4.
8. The battery cell according to claim 6, characterized in that: The battery cell is a wound battery cell formed by stacking and winding the first pole piece, the isolation film and the second pole piece. The battery cell includes a straight portion and a corner portion. The corner empty foil area of the battery cell pole piece structure is located at the corner portion of the battery cell.
9. The battery cell according to claim 8, characterized in that: The areas of the first pole piece located at the corners are all corner empty foil areas.
10. A battery, characterized in that: A battery cell comprising any one of claims 5 to 9.