Lithium battery roll core and lithium battery

Abstract

The utility model discloses a lithium battery roll core and a lithium battery, and belongs to the technical field of lithium batteries. The winding core comprises a first winding core, the first roll core comprises bending parts and an overlapping part, and the bending parts are located at the two ends of the overlapping part; the side face, where the non-bent portion is located, of the roll core body is an end face, the end face extends outwards to form a tab, and the tab extends outwards from the bent portion. According to the utility model, the tabs are moved to the two end parts of the battery cell from the position close to the middle part of the battery cell, so that the tabs are also wound when the battery cell is wound, and the tabs can be stretched on the roll shaft for winding the battery cell, thereby avoiding the problem of wrinkling or inward folding of the tabs.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium batteries, and in particular to a lithium battery coil and a lithium battery. Background Art

[0002] With the large-scale production and use of new energy vehicles, household gasoline vehicles are gradually being replaced by more and more new energy vehicles. The energy used in new energy vehicles is mostly lithium-ion batteries, and the safety and stability of lithium-ion batteries have always been an issue of increasing concern. The overcurrent capacity has an important impact on the safety of lithium-ion batteries. Conventional square wound battery cores have tabs on only one side, and there is a large margin in the width direction. The battery's overcurrent capacity is low. At the same time, the tabs are more likely to wrinkle and fold inward, causing lithium deposition and expansion of the battery cell, greatly affecting the cycle life of the battery cell. Utility Model Content

[0003] 1. Technical problems to be solved by the utility model

[0004] The purpose of the utility model is to provide a lithium battery core and a lithium battery to address the defects of existing square wound battery cells, such as insufficient current carrying capacity and easy wrinkling and inward folding of the tabs. By reasonably setting the position of the tabs, the wrinkle resistance and current carrying capacity of the battery cell are improved.

[0005] 2. Technical solution

[0006] In order to achieve the above-mentioned purpose, the technical solution provided by the present utility model is:

[0007] The present invention provides a lithium battery winding core, comprising a first winding core; the first winding core comprises a bent portion and an overlapping portion, the bent portions being located at both ends of the overlapping portion; the side surfaces of the first winding core where the non-bent portion is located being end surfaces, from which tabs extend outward, the tabs extending outward from the bent portions. This arrangement moves the tabs from a position near the middle of the battery cell to both ends of the battery cell, allowing them to be wound along with the battery cell during winding. The tabs can be stretched on the rollers used to wind the battery cell, thereby preventing them from wrinkling or folding inward.

[0008] As a further improvement of the present invention, the tab includes a tab connection portion that extends from one side of the end face to the other side of the end face in the width direction of the first winding core. This arrangement allows the tab to connect to all electrode sheets, ensuring that no electrode sheet is left without current.

[0009] As a further improvement of the present invention, a tab welding portion is provided on the tab connection portion, and the tab welding portion is bent toward the first winding core, so that the subsequent step of welding the tab to the conductive sheet is facilitated.

[0010] As a further improvement, the present invention also includes a second winding core with the same structure as the first. The first and second winding cores are placed in close proximity, with their large surfaces affixed together. This arrangement maximizes lithium battery space conservation, allowing more cells to be accommodated within a limited space.

[0011] As a further improvement to the present invention, the tab welding portion on the first winding core is bent toward the second winding core, and the tab welding portion on the second winding core is bent toward the first winding core. The tab welding portions on the first and second winding cores are arranged opposite each other. This arrangement allows the tabs of two battery cells to be welded to the same conductive sheet, saving battery cell parts, reducing costs, and further conserving internal space in the lithium battery.

[0012] The present invention also provides a lithium battery comprising the aforementioned lithium battery core, wherein the lithium battery core is disposed within a housing, one end of the housing being open, and the tab is connected to the terminal post via the opening. This arrangement facilitates the conduction of current from the tab.

[0013] As a further improvement of the present invention, a retaining frame is provided at the opening of the housing, and a conductive sheet is provided on the retaining frame. The tab is connected to the conductive sheet, and the conductive sheet is connected to the terminal post. This arrangement prevents the battery cell from moving within the housing, ensuring battery safety, and the conductive sheet can conduct current away from the tab.

[0014] As a further improvement of the present invention, a cover plate is provided on the stop frame, and the pole is fixed to the cover plate via a first fixing plate and a second fixing plate. This arrangement can fix the pole to prevent it from moving and causing battery failure.

[0015] As a further improvement of the present invention, an explosion-proof valve is provided on the cover plate, and an explosion-proof valve cover is provided on the explosion-proof valve. The provision of the explosion-proof valve can effectively prevent the battery from overheating and causing explosion.

[0016] 3. Beneficial effects

[0017] Compared with the existing known technologies, the technical solution provided by this utility model has the following significant effects:

[0018] The present invention provides a lithium battery winding core and lithium battery. The tabs are moved from near the center of the cell to the ends, allowing them to be wound along with the cell. The tabs can be stretched on the rollers used to wind the cell, thus preventing wrinkling or inward folding. Furthermore, the full tab structure is positioned at both ends of the winding core, fully utilizing the space along the core width. This significantly improves the core's current capacity compared to conventional winding cores that only have tabs on one side. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is an exploded diagram of the lithium battery structure of the present utility model;

[0020] Figure 2 This is a schematic diagram of the structure when two winding cores are connected together in the present invention;

[0021] Figure 3 This is a schematic structural diagram of a single winding core in the present invention;

[0022] Figure 4 It is a side view of a single winding core in the present invention.

[0023] Description of the numbers in the schematic diagram:

[0024] 1. Battery cell; 11. First winding core; 111. Overlapping portion; 112. Bending portion; 113. End face; 12. Second winding core; 13. Tab; 131. Tab connection portion; 132. Tab welding portion; 2. Casing; 31. Stop frame; 32. Conductive sheet; 33. Sealing ring; 34. Explosion-proof valve; 35. Cover plate; 36. Pole; 37. Explosion-proof valve cover; 38. First fixing plate; 39. Second fixing plate. DETAILED DESCRIPTION

[0025] In order to make the above-mentioned purposes, features and advantages of the utility model more clearly understood, the specific embodiments of the utility model are described in detail below with reference to the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the utility model. However, the utility model can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the connotation of the utility model. Therefore, the utility model is not limited to the specific embodiments disclosed below.

[0026] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation to the present invention.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this utility model, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0028] In this utility model, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0029] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0030] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0031] Example

[0032] Combine Figure 1 A lithium battery of this embodiment includes a cell 1 having a tab 13 disposed thereon. The cell 1 is disposed within a housing 2, wherein the housing 2 is a rectangular shell having an open end face, through which the tab 13 extends. A stopper 31 is disposed at the opening of the housing 2 and is connected to the cell 1 to secure it in place. A conductive sheet 32 ​​is disposed on the stopper 31, through which the tab 13 passes to connect.

[0033] In this embodiment, to ensure a secure connection between the tab 13 and the conductive sheet 32 ​​and enable current transmission, welding is used to connect the tab 13 and the conductive sheet 32. In this embodiment, a cover plate 35 is provided on the retaining frame 31, and a terminal 36 is disposed on the cover plate 35. In this embodiment, the terminal 36 passes through the cover plate 35. A first fixing plate 38 and a second fixing plate 39 are provided at each end of the terminal 36. The first and second fixing plates 38, 39 are located on either side of the cover plate 35, respectively, securing the terminal 36 to the cover plate 35. In this embodiment, a hole is formed in the cover plate 35, through which the terminal 36 passes and is threadedly connected to the second fixing plate 39. The diameter of the other end of the terminal 36 is larger than the diameter of the hole. The first fixing plate 38 is positioned between the other end of the terminal 36 and the cover plate 35, thereby securing the other end as well. In this embodiment, the conductive sheet 32 ​​is connected to the terminal 36, thereby electrically connecting the tab 13 and the terminal 36. In this embodiment, a sealing ring 33 is further provided at the connection between the pole 36 and the cover plate 35 .

[0034] In this embodiment, a pressure relief hole is provided on the stop frame 31 , and an explosion-proof valve 34 is provided on the cover plate 35 at a position corresponding to the pressure relief hole. In order to prevent dust from entering the explosion-proof valve 34 , an explosion-proof valve cover 37 is provided on the explosion-proof valve 34 .

[0035] Combine Figure 3-Figure 4The battery cell 1 of this embodiment is a lithium battery roll core, comprising a first roll core 11; the first roll core 11 comprises a bending portion 112 and an overlapping portion 111, with the bending portion 112 located at both ends of the overlapping portion 111; the side of the first roll core 11 where the non-bending portion 112 is located is an end face 113, and the end face 113 extends outwardly to form a tab 13, which extends outward from the bending portion 112. In this embodiment, the tab 13 is moved from a position near the middle of the battery cell 1 to both ends of the battery cell 1, so that the tab 13 is also wound when the battery cell 1 is wound. The tab 13 can be stretched on the roller that winds the battery cell 1, thereby avoiding the problem of wrinkling or inward folding. The tab 13 comprises a tab connection portion 131, which covers from one side of the end face 113 to the other side of the end face 113 in the width direction of the first roll core 11.

[0036] Combine Figure 2 The battery cell 1 of this embodiment includes a first winding core 11 and a second winding core 12. The structure of the second winding core 12 is identical to that of the first winding core 11. The first winding core 11 and the second winding core 12 are arranged in close proximity, with the large surfaces of the first and second winding cores 11 and 12 bonded together. In this embodiment, a tab welding portion 132 is provided on the tab connection portion 131. The tab welding portion 132 is bent toward one side. The tab welding portion 132 on the first winding core 11 is bent toward the second winding core 12, and the tab welding portion 132 on the second winding core 12 is bent toward the first winding core 11. The tab welding portions 132 on the first and second winding cores 11 and 12 are arranged opposite each other. In this embodiment, the tab welding portions 132 are bent, and the tab welding portions 132 on the two winding cores are arranged opposite each other, bending toward each other, so that the tabs 13 of the two winding cores can be welded to the same conductive sheet 32. This saves parts in the battery cell 1, reduces costs, and further saves space within the lithium battery.

[0037] The above is a schematic description of the present invention and its embodiments, which is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by this and, without departing from the inventive purpose of the present invention, designs a structure and embodiment similar to the technical solution without inventiveness, they shall fall within the scope of protection of the present invention.

Claims

1. A lithium battery winding core, comprising a first winding core (11); characterized in that: The first winding core (11) comprises a bending portion (112) and an overlapping portion (111), wherein the bending portion (112) is located at both ends of the overlapping portion (111); the side surface of the first winding core (11) where the non-bending portion (112) is located is an end surface (113), and the end surface (113) extends outward to form a pole lug (13), and the pole lug (13) extends outward from the position of the bending portion (112).

2. The lithium battery roll core according to claim 1, characterized in that: The tab (13) includes a tab connection portion (131), and the tab connection portion (131) covers from one side of the end surface (113) to the other side of the end surface (113) in the width direction of the first winding core (11).

3. The lithium battery roll core according to claim 2, characterized in that: A tab welding portion (132) is provided on the tab connecting portion (131), and the tab welding portion (132) forms a bent structure toward one side of the first winding core (11).

4. The lithium battery roll core according to claim 3, characterized in that: It also includes a second winding core (12), the structure of the second winding core (12) is the same as that of the first winding core (11).

5. The lithium battery roll core according to claim 4, characterized in that: The first winding core (11) and the second winding core (12) are arranged in close contact, and the large surfaces of the first winding core (11) and the second winding core (12) are bonded together.

6. The lithium battery roll core according to claim 4, characterized in that: The tab welding portion (132) on the first winding core (11) is bent toward the second winding core (12), and the tab welding portion (132) on the second winding core (12) is bent toward the first winding core (11). The tab welding portions (132) on the first winding core (11) and the second winding core (12) are arranged relative to each other.

7. A lithium battery, characterized in that: The invention comprises a lithium battery core as described in any one of claims 1 to 6, wherein the lithium battery core is arranged in a shell (2), one end of the shell (2) is open, and the tab (13) is connected to the pole (36) through the opening.

8. A lithium battery according to claim 7, characterized in that: A stop frame (31) is provided at the opening of the housing (2), a conductive sheet (32) is provided on the stop frame (31), the pole ear (13) is connected to the conductive sheet (32), and the conductive sheet (32) is connected to the pole (36).

9. A lithium battery according to claim 8, characterized in that: A cover plate (35) is provided on the stop frame (31), and the pole (36) is fixed on the cover plate (35) via a first fixing plate (38) and a second fixing plate (39).

10. A lithium battery according to claim 9, characterized in that: An explosion-proof valve (34) is arranged on the cover plate (35), and an explosion-proof valve cover (37) is arranged on the explosion-proof valve (34).

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