A winding core and a steel shell button type battery

Abstract

The utility model belongs to lithium battery technical field discloses a kind of roll core and steel shell button type battery. Roll core includes positive sheet, negative sheet and diaphragm, diaphragm is folded to form crease and open end, positive sheet is wrapped between diaphragm crease and open end, negative sheet, diaphragm and positive sheet are sequentially laminated and are formed cylindrical structure along winding central axis, the end of sheet is equipped with the current collector foil area of uncoated active layer, and constitutes foil lead-out area. Steel shell button type battery includes shell, and the roll core placed in shell, and the end surface of roll core is electrically connected with shell by tab or foil lead-out area. The steel shell button type battery of the utility model, the positive and negative poles of its roll core can be directly electrically connected with shell through foil lead-out area, without additional welding tab, and the equipment is more convenient.

Description

Technical Field

[0001] This utility model belongs to the field of lithium battery technology, specifically relating to a wound core and steel-cased button battery. Background Technology

[0002] A lithium-ion battery core, also known as a "bare cell (Jelly-Roll, JR)," is the core unit of the battery's internal energy storage structure. It is composed of a positive electrode, a negative electrode, and a separator, assembled through a precision winding process. Its function is to form the basic electrochemical reaction space of the battery. It requires strict isolation between the positive and negative electrodes to avoid short circuits, while the negative electrode must completely cover the positive electrode to ensure electrochemical stability.

[0003] However, in traditional wound core structures, electrodes are typically led out by welding tabs to the positive and negative electrode sheets, and then electrically connecting these tabs to the metal casing. While this connection method can meet the basic functional requirements of a battery to some extent, it has also revealed some problems that urgently need to be addressed during actual production. For example, the process of welding the tabs is quite complex, requiring precise operation and strict quality control. This not only increases production costs but may also affect the overall performance of the battery due to inconsistent welding quality. Furthermore, the cumbersome nature of this connection method also restricts the improvement of production efficiency to some extent, thus limiting the large-scale production and application of batteries. Utility Model Content

[0004] In view of this, the purpose of this utility model is to provide a winding core and a steel-cased button battery, which aims to solve the problem that the traditional winding core structure requires welding tabs to both the positive and negative electrodes and welding to connect the casing, resulting in a complicated manufacturing process.

[0005] This utility model solves the above-mentioned technical problems through the following technical means:

[0006] A winding core includes a positive electrode sheet, a negative electrode sheet, and a separator; the separator is folded in half to form a crease and an open end, and the positive electrode sheet is wrapped between the crease and the open end of the separator; the negative electrode sheet, the separator, and the positive electrode sheet are stacked in sequence and wound along a winding central axis to form a cylindrical structure;

[0007] Both the positive and negative electrode plates include a current collector and an active layer coated on the surface of the current collector;

[0008] The ends of the positive and / or negative electrode plates are provided with current collector foil areas that are not coated with an active layer, forming foil lead-out areas.

[0009] Furthermore, the opening end of the diaphragm is close to the first end face of the winding core, and the foil lead-out area on the negative electrode sheet is close to the second end face of the winding core opposite to the first end face.

[0010] Furthermore, the foil lead-out area is located at the starting end of the winding of the corresponding electrode sheet, and after winding, the foil lead-out area is folded outward.

[0011] Furthermore, the foil lead-out area is located at the winding end of the corresponding electrode sheet, and after winding, the foil lead-out area is folded inward.

[0012] Furthermore, the foil lead-out area is provided with several tabs.

[0013] Furthermore, the extension dimension of the foil lead-out area in the winding direction is greater than or equal to the positive or negative electrode sheet corresponding to the outermost ring of the core.

[0014] Furthermore, an insulating sheet is provided at the end of the winding core.

[0015] The present invention also provides a steel-cased button battery, including a casing and a core as described in this application placed inside the casing, wherein the end face of the core is electrically connected to the casing through tabs or empty foil areas that serve as sheet tabs.

[0016] Furthermore, one end of the core, which serves as the empty foil area of ​​the sheet-like electrode tab, is fixedly connected to the housing by a conductive adhesive material.

[0017] Furthermore, a circular metal disk is welded to one end of the core, which serves as the empty foil area of ​​the sheet-like electrode tab, and the circular metal disk is fixedly connected to the housing by a conductive adhesive material.

[0018] Beneficial effects:

[0019] The positive and negative electrodes of the core can be directly electrically connected to the shell through the empty foil area that acts as a tab, eliminating the need for additional soldering of the tabs and making the assembly more convenient. Attached Figure Description

[0020] Figure 1 This is a front view of the core before the foil lead-out area is folded in Example 1;

[0021] Figure 2 This is a front view of the core after the foil lead-out area is folded in Example 1;

[0022] Figure 3 This is a schematic diagram of the structure of the negative electrode foil lead-out area before it is cut in Example 1;

[0023] Figure 4 This is a schematic diagram of the positive electrode sheet in Example 1;

[0024] Figure 5 This is a schematic diagram of the structure of the negative electrode foil lead-out area after cutting in Example 2;

[0025] Figure 6This is a bottom view of the core after the foil lead-out area is folded in Example 2;

[0026] Figure 7 This is a schematic diagram of the structure of the positive electrode foil lead-out area before it is cut in Example 2;

[0027] Figure 8 This is a schematic diagram of the structure of the positive electrode foil lead-out area after cutting in Example 2;

[0028] Figure 9 This is a schematic diagram of the steel-cased button cell in Example 2;

[0029] The following labels are used in the attached diagram: 1. Positive electrode plate; 2. Negative electrode plate; 3. Diaphragm; 4. Electrode tab; 5. Foil lead-out area; 6. Core; 7. Shell; 8. Insulating sheet. Detailed Implementation

[0030] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can understand the advantages and effects of this utility model from the content disclosed in this specification. It should be noted that the illustrations provided in the following embodiments are for illustrative purposes only and represent schematic diagrams, not actual pictures. They should not be construed as limiting the utility model. To better illustrate the embodiments of this utility model, some components in the figures may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable that some well-known structures and their descriptions may be omitted in the figures for those skilled in the art.

[0031] In the figures of this utility model embodiment, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figure, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe the positional relationship in the figure are only for illustrative purposes and should not be construed as limiting this utility model. For those skilled in the art, the specific meaning of the above-mentioned terms can be understood according to the specific circumstances.

[0032] This utility model discloses a core, including a positive electrode 1, a negative electrode 2 and a separator 3. The separator 3 is folded to form a crease and an open end. The positive electrode 1 is wrapped between the crease and the open end of the separator 3. The negative electrode 2, the separator 3 and the positive electrode 1 are stacked in sequence and wound along the winding center axis to form a cylindrical structure.

[0033] Both the positive electrode 1 and the negative electrode 2 include a current collector and an active layer coated on the surface of the current collector;

[0034] The ends of the positive electrode 1 and / or the negative electrode 2 are provided with current collector foil areas that are not coated with an active layer, forming foil lead-out areas 5.

[0035] This utility model also discloses a steel-cased button battery, including a casing 7 and the aforementioned core 6 placed inside the casing 7. The end face of the core 6 is electrically connected to the casing 7 through a tab 4 or a foil lead-out area 5 that serves as a sheet-like tab.

[0036] One end of the core 6 with the foil lead-out area 5 is fixedly connected to the housing 7 by conductive adhesive or other conductive bonding material, or a circular metal disk is first welded on, and then the circular metal disk is fixedly connected to the housing 7 by conductive bonding material.

[0037] Example 1

[0038] like Figures 1-4 As shown, this embodiment discloses a core, including a positive electrode 1, a negative electrode 2 and a separator 3. The separator 3 is folded in half to cover the positive electrode 1, and the negative electrode 2 and the positive electrode 1 covered by the separator 3 are sequentially stacked and wound to form a cylinder.

[0039] The head of the positive electrode 1 has an empty foil area for welding the tab 4;

[0040] The negative electrode 2 has a wider tail end, used as the starting or ending point for winding. A foil lead-out area 5 is connected to the tail end of the negative electrode 2. If the foil lead-out area 5 is located at the starting end of the winding of the corresponding electrode, it is folded outwards after winding. If the foil lead-out area 5 is located at the ending end of the winding of the corresponding electrode, it is folded inwards after winding. The bent foil lead-out area is electrically connected to the housing 7.

[0041] In a preferred embodiment, the opening end of the diaphragm 3 is close to the first end face of the core 6, and the foil lead-out area 5 on the negative electrode 2 is close to the second end face of the core 6 opposite to the first end face. This avoids short circuits caused by the foil lead-out area 5 coming into contact with the positive electrode 1 after folding.

[0042] As a preferred embodiment, the extension dimension of the foil lead-out area 5 in the winding direction is greater than or equal to the positive electrode 1 or negative electrode 2 corresponding to the outermost ring of the core 6.

[0043] As a preferred embodiment, an insulating sheet 8 is attached to the end of the core 6 to prevent the foil lead-out area from contacting the core 6 after folding.

[0044] This embodiment also discloses a steel-cased button battery, including a casing 7 and the aforementioned winding core 6 placed inside the casing 7. The end face of the winding core 6 is electrically connected to the casing 7 through a tab 4 or a foil lead-out area 5.

[0045] One end of the core 6 with the foil lead-out area is fixedly connected to the housing 7 by a conductive adhesive material, or a circular metal disk is first welded on, and then the circular metal disk is fixedly connected to the housing 7 by a conductive adhesive material.

[0046] In this embodiment, the housing 7 consists of an upper housing and a lower housing. The bottom of the lower housing is a flat surface, which can be directly connected to the foil lead-out area 5 of the negative electrode 2. Alternatively, conductive adhesive or other conductive bonding materials can be injected into the bottom of the lower housing in advance for fixation.

[0047] Example 2

[0048] In this embodiment, the structure of the core 6 is the same as that of the core 6 in Embodiment 1, except that: in this embodiment, the foil lead-out area 5 at the tail of the negative electrode sheet 2 is provided with several electrode tabs, which are formed by cutting. This structural design facilitates folding. Figure 5 and Figure 6 As shown. The tail of the positive electrode 1 is also connected to a foil lead-out area 5, and the foil lead-out area 5 at the tail of the positive electrode 1 is also provided with several tabs, such as... Figure 7 and Figure 8 As shown.

[0049] In this embodiment, the assembly of the winding core 6 and the casing 7 yields a steel-cased button battery. The assembled product is as follows: Figure 9 As shown.

[0050] The above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the spirit and scope of the technical solutions of this utility model, and all such modifications and substitutions should be covered within the scope of the claims of this utility model. Technologies, shapes, and structural parts not described in detail in this utility model are all known technologies.

Claims

1. A winding core, characterized in that: It includes a positive electrode, a negative electrode, and a separator; the separator is folded in half to form a crease and an open end, and the positive electrode is wrapped between the crease and the open end of the separator; the negative electrode, the separator, and the positive electrode are stacked in sequence and wound along the central axis to form a cylindrical structure; Both the positive and negative electrode plates include a current collector and an active layer coated on the surface of the current collector; The ends of the positive and / or negative electrode plates are provided with current collector foil areas that are not coated with an active layer, forming foil lead-out areas.

2. A winding core according to claim 1, characterized in that: The opening end of the diaphragm is close to the first end face of the winding core, and the foil lead-out area on the negative electrode sheet is close to the second end face of the winding core opposite to the first end face.

3. A winding core according to claim 1, characterized in that: The foil lead-out area is located at the starting end of the winding of the corresponding electrode sheet, and after winding, the foil lead-out area is folded outward.

4. A winding core according to claim 1, characterized in that: The foil lead-out area is located at the winding end of the corresponding electrode sheet, and after winding, the foil lead-out area is folded inward.

5. A winding core according to claim 4, characterized in that: The foil lead-out area is provided with several tabs.

6. A winding core according to claim 1, characterized in that: The extension dimension of the foil lead-out area in the winding direction is greater than or equal to the positive or negative electrode corresponding to the outermost ring of the core.

7. A winding core according to claim 1, characterized in that: An insulating sheet is provided at the end of the winding core.

8. A steel-cased button cell battery, characterized in that: It includes a housing and a core as described in any one of claims 1-7, placed within the housing, wherein the end face of the core is electrically connected to the housing via a tab or an empty foil region that serves as a sheet tab.

9. A steel-cased button battery according to claim 8, characterized in that: The end of the core, which serves as the empty foil area for sheet-like tabs, is fixedly connected to the housing by a conductive adhesive material.

10. A steel-cased button battery according to claim 8, characterized in that: The core has a circular metal disk welded to one end, which serves as the empty foil area of ​​the sheet-like electrode tab. The circular metal disk is fixedly connected to the housing by a conductive adhesive material.

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