Winding battery cell structure, battery and electric equipment
By adopting the active material layer design with overlapping projections on both sides of the end section of the first electrode sheet of the wound cell, the fracture problem caused by cathode tailing dislocation is solved, and the stability and reliability of the cell are improved.
Patent Information
- Application Number
- CN202421392749.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-18
- Publication Date
- 2025-07-04
- Estimated Expiration
- 2034-06-18
AI Technical Summary
The single and double-sided misalignment of the cathode end portion of the existing wound cell leads to concentrated stress during the cycle, resulting in fracture, reducing the safety and stability of the cell use.
The first end section of the first end section of the first pole sheet is designed with overlapping projections, and the coating misalignment areas are eliminated to achieve alignment and ending, and avoid breaking on both sides of the pole sheet.
It improves the stability of the battery cell structure, ensures the reliability of the battery cell circulation, and avoids the fracture of the pole sheet during the cycle.
Smart Images
Figure CN223066212U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of batteries, and particularly relates to a wound battery cell structure, a battery and an electrical equipment using the same. Background Art
[0002] In recent years, the market has a higher demand for the energy density of consumer battery cells. Battery cell manufacturers usually increase the energy density of wound battery cells by increasing the compaction density of the electrode sheets and reducing the thickness of the foil materials.
[0003] However, the end part of the cathode of the existing wound battery cell is arranged with single-sided and double-sided dislocation. However, during the winding and compaction process, the rolling method of the cathode will cause excessive extension of the aluminum foil at the dislocation junction of the single-sided and double-sided electrode material areas of the cathode, resulting in stress concentration points. Therefore, during the cycling process of the finished battery cell, the dislocation junction of the single-sided and double-sided electrode material areas of the cathode breaks due to excessive stress caused by cyclic expansion, thereby reducing the safety and stability of use. Summary of the Utility Model
[0004] The purpose of the utility model is to provide a wound battery cell structure aiming at the deficiencies of the prior art, which can solve the technical problem of low use stability of the existing wound battery cells.
[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:
[0006] A wound battery cell structure includes a separator, a first electrode sheet and a second electrode sheet; the separator is arranged between the first electrode sheet and the second electrode sheet, and the first electrode sheet, the separator and the second electrode sheet are stacked.
[0007] The first electrode sheet includes a first current collector and first active material layers connected to both side surfaces of the first current collector; the first current collector includes a first starting section, a first main section and a first ending section connected in sequence; on both sides of the first ending section, the projections of the corresponding first active material layers towards the first ending section completely overlap.
[0008] Preferably, on both sides of the first starting section, the projections of the two first active material layers towards the first starting section completely overlap.
[0009] Preferably, on both sides of the first ending section, the projections of the two first active material layers towards the first ending section both overlap with the first ending section.
[0010] Preferably, on both sides of the first starting section, the projections of the two first active material layers towards the first starting section both overlap with the first ending section.
[0011] Preferably, the second electrode plate includes a second current collector and second active material layers disposed on both side surfaces of the second current collector;
[0012] When the second electrode plate is unfolded and on both sides of the second current collector, there is at least a partially overlapping area between the projections of the two second active material layers respectively towards the second current collector, and the projection of the first active material layer towards the second current collector is disposed within the overlapping area.
[0013] Preferably, the second current collector includes a second starting section, a second main section, and a second ending section connected in sequence; first starting coatings and second starting coatings are provided on both side surfaces of the second starting section, and the coating length of the first starting coating is greater than that of the second starting coating; first ending coatings and second ending coatings are provided on both side surfaces of the second ending section; the coating length of the first ending coating is greater than that of the second ending coating; and the first ending coating and the second starting coating are respectively on the same side surface of the second current collector.
[0014] Preferably, the second ending section includes a double-sided coated section, a single-sided coated section, and an empty foil metal section connected in sequence; at least part of the structure of the single-sided coated section, the first ending section, and the double-sided coated section are stacked; the empty foil area is disposed on the single-sided coated section or the double-sided coated section; the second active material layer is connected to the side surface of the single-sided coated section facing the first electrode plate; the second active material layer is connected to both side surfaces of the double-sided coated section.
[0015] Preferably, the first electrode plate is a cathode plate; the second electrode plate is an anode plate.
[0016] The present invention also discloses a battery, including the winding core structure described above.
[0017] The present invention also discloses an electrical device, including the battery described above.
[0018] The beneficial effect of the present invention is that in this technical solution, by using first active material layers with overlapping projections on both sides of the first ending section of the first electrode plate, the coating misalignment area at the tail of the first electrode plate is eliminated, so as to achieve aligned ending, and further effectively avoid phenomena such as fracture at the single-sided and double-sided parts of the first electrode plate during the cycling process, thereby improving the structural stability and ensuring the reliability of the core cycling. Description of the Drawings
[0019] The following will describe the features, advantages, and technical effects of the exemplary embodiments of the present invention with reference to the attached Figures 1 to 7 drawings.
[0020] Figure 1 Structural schematic diagram of the wound battery cell structure according to an embodiment of the present utility model;
[0021] Figure 2 Structural schematic diagram of the wound battery cell structure according to an embodiment of the present utility model;
[0022] Figure 3 Partial enlarged view of the end section of the wound battery cell structure according to an embodiment of the present utility model;
[0023] Figure 4 Partial enlarged view of the starting section of the wound battery cell structure according to an embodiment of the present utility model;
[0024] Figure 5 Structural schematic diagram of the second pole piece of the wound battery cell structure according to an embodiment of the present utility model;
[0025] Figure 6 Structural schematic diagram of the wound battery cell structure according to an embodiment of the present utility model;
[0026] Figure 7 Relationship diagram between the conventional cathode single-sided area end structure and the wound battery cell structure according to an embodiment of the present utility model under 25°C cycle data;
[0027] Figure 8 CT diagram of the conventional cathode single-sided area end structure and the wound battery cell structure according to an embodiment of the present utility model after 700 cycles at 45°C.
[0028] In the figure: 1 - Separator; 2 - First pole piece; 201 - First current collector; 202 - First active material layer; 21 - First end section; 22 - First main body section; 23 - First starting section; 3 - Second pole piece; 31 - Second starting section; 32 - Second main body section; 33 - Second end section; 3301 - Dislocation segmentation; 3302 - Single-sided coating segmentation; 3303 - Empty foil metal segmentation; 301 - Second active material layer; 3011 - First starting coating; 3012 - Second starting coating; 3013 - First end coating; 3014 - Second end coating; 302 - Second current collector; 4 - Corner; 5 - Straight section. Detailed implementation manners
[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill 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" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusion.
[0030] In the description of the embodiments of the present application, technical terms such as "first" and "second" are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity, specific order or primary-secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality" is more than two, unless otherwise specifically defined.
[0031] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.
[0032] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, or there are multiple situations where A exists alone. In addition, the character " / " in this text generally indicates that the associated objects before and after are in an "or" relationship.
[0033] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "install", "connect", "link", "fix", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can also be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components. 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 specific situations.
[0034] The following is a further detailed description of the present utility model in conjunction with the attached Figures 1 to 7 This is not a limitation to the present utility model.
[0035] Such as Figure 1 and 2As shown, in an embodiment of the present utility model, the winding cell structure includes a separator 1, a first electrode tab 2, and a second electrode tab 3. The separator 1 is disposed between the first electrode tab 2 and the second electrode tab 3, and the first electrode tab 2, the separator 1, and the second electrode tab 3 are stacked and wound together to form a core body. The first electrode tab 2 includes a first current collector 201 and first active material layers 202 connected to both side surfaces of the first current collector 201. The first current collector 201 includes a first starting section 23, a first main section 22, and a first ending section 21 connected in sequence. The first starting section 23 is disposed on the inner circle of the core body. The first ending section 21 is disposed on the outer circle of the core body. One end of the second electrode tab 3 is disposed on the outermost circle of the core body. On both sides of the first ending section 21, the projections of the two first active material layers 202 towards the first ending section 21 completely overlap.
[0036] The technical solution of the present utility model adopts the first active material layers 202 with overlapping projections on both sides of the first ending section 21 of the first electrode tab 2 to cancel the coating misalignment area at the tail of the first electrode tab 2, thereby achieving aligned ending, and further effectively avoiding phenomena such as breakage at the single-sided and double-sided parts of the first electrode tab during the cycling process, thus improving the structural stability and ensuring the reliability of the cell cycling.
[0037] Specifically, in some embodiments, the first electrode tab 2 is a cathode tab; the second electrode tab 3 is an anode tab. Of course, in other embodiments, the first electrode tab 2 is an anode tab; the second electrode tab 3 is a cathode tab. However, the preferred solution is that the first electrode tab 2 is a cathode tab; the second electrode tab 3 is an anode tab. This structure cancels the single-sided area with coating misalignment at the first ending section 21 of the cathode tab, thereby effectively avoiding phenomena such as breakage at the single-sided and double-sided parts of the first electrode tab during the cycling process, and further improving the structural stability and ensuring the reliability of the cell cycling.
[0038] Specifically, in some embodiments, such as Figure 1 and 2 as well as shown in 4, on both sides of the first starting section 23, the projections of the two first active material layers 202 towards the first starting section 23 completely overlap. By adopting the first active material layers 202 with overlapping projections on both sides of the first starting section 23 and both sides of the first ending section 21 of the first electrode tab 2, this structure can achieve aligned coating at both ends of the first electrode tab, thereby further improving the structural stability and reducing the breakage area.
[0039] Specifically, in some embodiments, such as Figure 1 、 2, as shown in FIGS. 3, on both sides of the first end section 21, the projections of the corresponding first active material layer 202 towards the first end section 21 coincide with the first end section 21; on both sides of the first start section 23, the projections of the first active material layer 202 towards the first start section 23 coincide with the first end section 21. That is to say, the lengths of the first active material layer 202 on both sides of the first current collector 201 of the first electrode tab 2 are the same to achieve a flush setting, so as to effectively avoid phenomena such as breakage at the single-sided and double-sided parts of the first electrode tab during the cycling process, thereby improving the structural stability and ensuring the reliability of the cell cycling.
[0040] Specifically, in some embodiments, such as Figure 1 and 2 as well as shown in FIG. 5, the second electrode tab 3 includes a second current collector 302 and second active material layers 301 provided on both side surfaces of the second current collector 302; when the second electrode tab 3 is unfolded and on both sides of the second current collector 302, there is at least a partial overlapping area between the projections of the two second active material layers 301 towards the second current collector 302, and the projection of the first active material layer 202 towards the second current collector 302 is arranged within the overlapping area. That is to say, the coatings on the upper and lower sides of the second electrode tab 3 are arranged in a staggered manner and cover the first electrode tab 2 and its active material layer, so as to avoid the problem of electrode tab breakage at the misaligned junction of the cathode single-sided and double-sided coating areas caused by cell expansion during the cycling process.
[0041] Specifically, in some embodiments, such as Figure 1 and 2 as well as shown in FIGS. 3 and 4, the second current collector 302 includes a second start section 31, a second main section 32 and a second end section 33 connected in sequence; on both side surfaces of the second start section 31, there are a first start coating 3011 and a second start coating 3012, and the coating length of the first start coating 3011 is greater than that of the second start coating 3012; on both side surfaces of the second end section 33, there are a first end coating 3013 and a second end coating 3014; the coating length of the first end coating 3013 is greater than that of the second end coating 3014; and the first end coating 3013 and the second start coating 3012 are respectively on the same side surface of the second current collector 302; the second end coating 3014 and the first start coating 3011 are respectively on the same side surface of the second current collector 302. This structure can avoid the problem of electrode tab breakage at the misaligned junction of the cathode single-sided and double-sided coating areas caused by cell expansion during the cycling process through the staggered coating arrangement on both side surfaces of the start section and the end section of the second electrode tab and the overlapping coating in the middle section, and covering the first electrode tab 2 and its active material layer.
[0042] Specifically, in some embodiments, such as Figure 1 、 2As shown in FIGS. 5 and 6, the second end section 33 includes a double-sided coated section 3301, a single-sided coated section 3302, and an empty foil metal section 3303 that are connected in sequence; at least part of the structure in the single-sided coated section 3302, the first end section 21, and the double-sided coated section 3301 are stacked; the empty foil area 303 is arranged in the single-sided coated section 3302; the second active material layer 301 is connected to the side surface of the single-sided coated section 3302 facing the first pole piece 2; the second active material layer 301 is connected to both side surfaces of the double-sided coated section 3301; and the empty foil metal section 3303 is arranged on the outermost circle of the core body and at the corners 4 and straight sections 5 of the core body; the double-sided coated section 3301 is arranged at the straight section 5 of the core body; the single-sided coated section 3302 is arranged at the corners 4 and straight sections 5 of the core body. By arranging the empty foil area 303 on the double-sided coated section 3301 in the second outermost circle, this structure can effectively buffer the stress on the outermost cathode sheet, avoid excessive extension of the metal at the misaligned junction of the single and double material areas on the outer circle of the original cathode sheet, and thus avoid the fracture caused by excessive stress at the misaligned junction of the single and double material areas of the cathode due to cyclic expansion; furthermore, the stability of the structure is improved, and the reliability of the cell cycle is ensured. In addition, the single-sided coated section 3302 with single-layer coating on the outermost circle can separate the outermost circles of the first pole piece 2 and the second pole piece 3, improving the stability of use; and the empty foil metal section 3303 on the outermost circle improves the convenience and stability of the outermost winding assembly.
[0043] Experiment 1:
[0044] Use the cell 664863 to judge the fracture situation of the cathode sheet during the cell cycle under the conventional (cathode single-sided area end) winding method and the winding method of cathode alignment and anode misaligned coating of the present application.
[0045] Conclusion: According to the Figure 7 coordinate data shown, the cell cycle trend of the structure of the present application is normal, while the capacity of the cell with the conventional cathode single-sided area end drops suddenly during the cycle due to the fracture of the cathode sheet.
[0046] Experiment 2:
[0047] Use the cell 664863 under the conventional (cathode single-sided area end) winding method and the winding method of cathode alignment and anode misaligned coating of the present application, and after cycling 700 weeks at the same 45°C, judge the fracture situation of the cathode sheet during the cell cycle.
[0048] Conclusion: According to the Figure 8The CT view data shown indicates that for the conventional cathode single-sided area finishing structure (the left image in the CT diagram), the electrode plate breaks at the misaligned junction of the outermost cathode single- and double-sided material areas of the battery cell, while in this structure (the right image in the CT diagram), the single-sided area is eliminated, the battery cell structure is complete, and the risk of the outermost cathode electrode plate breaking is avoided.
[0049] The present utility model also proposes a battery, which includes a wound battery cell structure. The specific structure of the wound battery cell structure refers to the above-mentioned embodiments. Since this battery 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, and will not be elaborated here one by one.
[0050] Among them, a battery refers to a cup, tank or other container or part of the space of a composite container containing an electrolyte solution and metal electrodes to generate current, and is a device that can convert chemical energy into electrical energy; a battery has a positive electrode and a negative electrode.
[0051] The present utility model also proposes an electrical equipment, which includes a battery. The specific structure of the battery refers to the above-mentioned embodiments. Since this electrical equipment 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, and will not be elaborated here one by one.
[0052] Among them, the electrical equipment can be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, etc. The vehicle can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc.; the spacecraft includes an airplane, a rocket, a space shuttle, a spaceship, etc.; the electric toy includes a fixed or mobile electric toy, for example, a game console, an electric vehicle toy, an electric ship toy, an electric airplane toy, etc.; the electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool and a railway electric tool, for example, an electric drill, an electric grinder, an electric wrench, an electric screwdriver, a hammer drill, an impact electric drill, a concrete vibrator, a power planer, etc. The embodiments of the present application do not impose special restrictions on the above-mentioned electrical equipment.
[0053] In addition, it should be understood that although this specification is described according to the embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
[0054] Based on the disclosure and teachings of the above specification, those skilled in the art to which the present utility model pertains are also able to make changes and modifications to the above embodiments. Therefore, the present utility model is not limited to the above specific embodiments, and any obvious improvements, substitutions or variations made by those skilled in the art on the basis of the present utility model all fall within the protection scope of the present utility model. In addition, although some specific terms are used in this specification, these terms are only for convenience of description and do not constitute any limitation to the present utility model.
Claims
1. A wound battery cell structure, characterized in that: It includes a separator, a first electrode sheet, and a second electrode sheet; the separator is disposed between the first electrode sheet and the second electrode sheet, and the first electrode sheet, the separator, and the second electrode sheet are stacked and wound together to form a wound core body; The first electrode sheet includes a first current collector and first active material layers connected to both side surfaces of the first current collector; the first current collector includes a first starting segment, a first main segment, and a first ending segment connected in sequence; on both sides of the first ending segment, the projections of the two first active material layers towards the first ending segment completely overlap.
2. The winding battery cell structure according to claim 1, wherein: On both sides of the first starting segment, the projections of the two first active material layers towards the first starting segment completely overlap.
3. The winding cell structure according to claim 2, wherein: On both sides of the first ending segment, the projections of the two first active material layers towards the first ending segment both overlap with the first ending segment.
4. The winding cell structure according to claim 2 or 3, characterized in that: On both sides of the first starting segment, the projections of the two first active material layers towards the first starting segment both overlap with the first ending segment.
5. The winding cell structure according to claim 1, wherein: The second electrode sheet includes a second current collector and second active material layers disposed on both side surfaces of the second current collector; When the second electrode sheet is unfolded and on both sides of the second current collector, there is at least a partially overlapping area between the projections of the two second active material layers towards the second current collector, and the projection of the first active material layer towards the second current collector is disposed within the overlapping area.
6. The winding core structure according to claim 5, wherein: The second current collector includes a second starting segment, a second main segment, and a second ending segment connected in sequence; on both side surfaces of the second starting segment, there are a first starting coating and a second starting coating, and the coating length of the first starting coating is greater than that of the second starting coating; on both side surfaces of the second ending segment, there are a first ending coating and a second ending coating; The coating length of the first ending coating is greater than that of the second ending coating; and the first ending coating and the second starting coating are respectively on the same side surface of the second current collector.
7. The winding cell structure according to claim 6, wherein: The second ending segment includes a double-sided coated segment, a single-sided coated segment, and an empty foil metal segment connected in sequence; at least part of the structure of the single-sided coated segment, the first ending segment, and the double-sided coated segment are stacked; the empty foil metal segment is disposed on the single-sided coated segment or the double-sided coated segment; the second active material layer is connected to the side surface of the single-sided coated segment facing the first electrode sheet; the second active material layer is connected to both side surfaces of the double-sided coated segment.
8. The winding cell structure according to claim 1, wherein: The first electrode sheet is a cathode sheet; the second electrode sheet is an anode sheet.
9. A battery, characterized in that: It includes the wound cell structure according to any one of claims 1 to 8 above.
10. An electrical device, characterized in that: It includes the battery according to claim 9 above.