Cylindrical battery

Abstract

The utility model discloses a cylindrical battery, which belongs to the field of lithium battery manufacturing and comprises a cylindrical shell, a roll core arranged in the shell, a positive collector plate and a negative collector plate arranged at two ends of the roll core, and a positive cover component and a negative cover component arranged at two ends of the shell, wherein a positive pole lug and a negative pole lug which are respectively connected with the positive pole current collecting disc and the negative pole current collecting disc are arranged at two ends of the roll core, the positive pole cover assembly and the negative pole cover assembly are respectively connected with the positive pole current collecting disc and the negative pole current collecting disc, and a plurality of hollow grooves which are combined into a ring shape are formed in the positive pole current collecting disc and the negative pole current collecting disc. The positive pole lug and the negative pole lug penetrate through the through holes. Through the structural design of the positive collector plate and the negative collector plate, the tabs penetrate through the hollowed-out grooves in the battery assembly process, then the tabs and the collector plates are connected, the opposite arrangement mode of the collector plates and the tabs can be changed, the energy density of the battery can be improved through the structure, and welding slag can be reduced.

Description

Technical Field

[0001] The utility model relates to the field of lithium battery manufacturing, in particular to a cylindrical battery. Background Art

[0002] Developing new energy vehicles is the only way for my country to move from a large automobile country to a powerful automobile country, and it is also a measure to cope with climate change and promote green development. At present, the market penetration rate of new energy vehicles has reached nearly 30%, among which high energy density, long cycle life and fast charging have become the common pursuit of lithium battery manufacturers and the market.

[0003] As the power source of new energy vehicles, the safety of power batteries is directly related to the life safety of users. With its advantages of high capacity, high rate and low cost, the 4680 cylindrical battery is expected to become the standard model of cylindrical power batteries in the future. The full-ear design of this battery reduces the length of the electron flow path and reduces the internal resistance, thereby supporting high-current fast charging. Compared with small cylindrical batteries, the 4680 cylindrical battery has an additional collector plate for each positive and negative electrode in structure to increase the current conduction area.

[0004] However, during the welding process between the tab and the collector plate, the full tab design may hinder the removal of welding slag because the collector plate is located at the top and the tab is located at the bottom. The residual welding slag may cause a short circuit inside the battery cell, thereby affecting the safety performance of the battery. Utility Model Content

[0005] The utility model aims to provide a cylindrical battery, which solves the problem that in the cylindrical battery with full-ear design in the prior art, the positional relationship between the collector plate and the ear will hinder the removal of welding slag, thereby affecting the safety performance of the battery.

[0006] In order to achieve the above-mentioned purpose, the utility model provides a cylindrical battery, which at least includes a cylindrical shell, a winding core arranged in the shell, a positive current collecting disk and a negative current collecting disk arranged at both ends of the winding core, and a positive cover assembly and a negative cover assembly arranged at both ends of the shell, wherein the two ends of the winding core have positive pole ears and negative pole ears connected to the positive current collecting disk and the negative current collecting disk, respectively, the positive cover assembly and the negative cover assembly are respectively connected to the positive current collecting disk and the negative current collecting disk, wherein the positive pole ear and the negative pole ear pass through the positive current collecting disk and the negative current collecting disk, respectively, and are attached to the surfaces of the positive current collecting disk and the negative current collecting disk, a boss connected to the positive cover assembly is arranged at the center of the positive current collecting disk, and the edge of the negative current collecting disk is bent toward the negative cover assembly to form a peripheral portion connected to the negative cover assembly.

[0007] Specifically, the positive collector and the negative collector are provided with a plurality of hollow grooves in a ring shape, for the positive and negative pole ears to pass through and fit on the surface of the positive and negative collectors. The positive and negative pole ears pass through the positive and negative collectors and then are welded, which can reduce the generation of welding slag and facilitate the cleaning of welding slag; in addition, the boss and the peripheral portion are provided to prevent the positive and negative pole ears from being attached to the positive and negative collectors, affecting the normal transmission of current, and ensuring the stable operation of the battery.

[0008] The positive electrode cover assembly includes a positive electrode cover plate and a positive terminal connected to the positive electrode cover plate. The positive terminal protrudes toward the winding core relative to the positive electrode cover plate to connect to the boss, so as to cooperate with the boss to ensure the normal transmission of current. The outer end of the positive terminal has a recessed portion that penetrates into the interior of the shell to enhance the structural stability. In addition, the peripheral portion of the negative electrode collector is provided with several notches at equal intervals around its axis to enhance the stability of its subsequent connection with the end cover, and an injection hole is provided in the center of the negative electrode collector to facilitate the subsequent injection of electrolyte.

[0009] Furthermore, the plurality of hollow grooves are arranged at equal intervals around the axis of the positive current collector disk or the negative current collector disk, and the positive electrode tabs and the negative electrode tabs passing through the hollow grooves fall toward the axis of the positive current collector disk or the negative current collector disk, providing a specific implementation scheme to ensure that the positive and negative electrode tabs pass through the positive and negative current collector disks respectively, and that the positive and negative electrode tabs are attached to the positive and negative current collector disks.

[0010] In a possible implementation, the plurality of hollow grooves on the negative electrode current collector disc are divided into at least two groups according to the distance between them and the axis of the negative electrode current collector disc, and the hollow grooves in the outer layer extend along the arc where they are longer than the hollow grooves in the inner layer; the plurality of hollow grooves on the positive electrode current collector disc are divided into at least two groups according to the distance between them and the axis of the positive electrode current collector disc, and the hollow grooves in the outer layer extend along the arc where they are longer than the hollow grooves in the inner layer. A possible implementation of the positive and negative electrode tabs passing through the positive and negative electrode current collector discs is provided, and this arrangement can ensure that the tabs transmit current stably.

[0011] In another possible implementation, the plurality of hollow grooves on the negative electrode collector disc are divided into at least two groups according to the distance between them and the axis of the negative electrode collector disc, and the hollow grooves in the outer layer have a longer extension length along the arc where they are located than the hollow grooves in the inner layer; the plurality of hollow grooves on the positive electrode collector disc have one group according to the distance between them and the axis of the negative electrode collector disc, and in addition, there is a gap between the edge of the positive electrode collector disc and the inner side wall of the shell for the positive electrode tab to pass through to form a second group of positive electrode tabs. In this way, another implementation of the positive and negative electrode tabs passing through the positive and negative electrode collector discs is provided. The negative electrode collector disc in this arrangement is easier to process, but the assembly requirements are higher.

[0012] Preferably, in the above embodiments, the number of each group of hollow grooves is at least 3, so as to ensure that the tab can stably transmit current.

[0013] Compared with the existing known technology, the technical solution provided by the utility model has the following advantages:

[0014] Beneficial effects:

[0015] The utility model provides a cylindrical battery. Through the structural design of the positive electrode collector and the negative electrode collector, the pole ear is passed through the hollow groove during the battery assembly process, and then the pole ear and the collector are connected, which can change the relative arrangement of the collector and the pole ear. This structure can improve the energy density of the battery, reduce the generation of welding slag, and can also more conveniently clean the welding slag and reduce the residual welding slag, thereby improving the safety performance of the battery. In addition, the positive electrode cover assembly and the negative electrode cover assembly are correspondingly optimized in structure, which can ensure the normal transmission of the battery current and improve the overall structural stability of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In the drawings, the sizes and proportions do not represent the sizes and proportions of actual products. The drawings are merely illustrative, and some non-essential elements or features are omitted for clarity.

[0017] Figure 1 This is a schematic diagram of the structure of a cylindrical battery in Example 1 of the utility model;

[0018] Figure 2 This is a schematic diagram of the structure of one side of the positive electrode ear of the winding core in Example 1 of the utility model;

[0019] Figure 3 This is a schematic diagram of the structure of one side of the negative electrode tab of the winding core in Example 1 of the utility model;

[0020] Figure 4 It is a schematic diagram of the structure of the positive electrode current collecting disk in Example 1 of the utility model;

[0021] Figure 5 It is a schematic diagram of the structure of the negative electrode current collector in Example 1 of the utility model;

[0022] Figure 6 This is a schematic diagram of the structure of the assembly of the winding core and the positive electrode current collecting disk in Example 1 of the utility model;

[0023] Figure 7 This is a schematic diagram of the structure of the assembly of the winding core and the negative electrode current collecting disc in Example 1 of the utility model;

[0024] Figure 8 This is a schematic diagram of the structure of one side of the positive electrode ear of the winding core in Example 2 of the utility model;

[0025] Fig. 9 It is a schematic diagram of the structure of the positive electrode current collecting disk in Example 2 of the utility model;

[0026] Fig.10 This is a schematic diagram of the structure of the assembly of the winding core and the positive electrode current collecting disk in Example 2 of the utility model;

[0027] Fig.11 This is a schematic structural diagram of the positive terminal of a cylindrical battery in Embodiment 2 of the present utility model;

[0028] Fig.12 It is a schematic structural diagram of the negative terminal of a cylindrical battery in Example 2 of the present utility model.

[0029] Description of Reference Numerals

[0030] 1. Shell; 2. Winding core; 201. Positive electrode tab; 202. Negative electrode tab; 3. Positive electrode collector plate; 4. Negative electrode collector plate; 401. Peripheral portion; 402. Notch; 403. Liquid injection hole; 5. Positive electrode cover assembly; 501. Positive electrode cover plate; 502. Positive electrode terminal; 503. Recessed portion; 6. Negative electrode cover assembly; 7. Hollow groove. DETAILED DESCRIPTION

[0031] The present invention will be described in detail with reference to the accompanying drawings. What is described here is only a preferred embodiment of the present invention, and those skilled in the art can think of other ways to implement the present invention based on the preferred embodiment, and other ways also fall within the scope of the present invention.

[0032] Example 1

[0033] This embodiment provides a cylindrical battery to solve the problem in the prior art that the positional relationship between the current collecting plate and the tabs in a conventional cylindrical battery with a full-tab design will hinder the removal of welding slag, thereby affecting the safety performance of the battery.

[0034] Specifically, Figure 1 As shown, a cylindrical battery comprises a housing 1 having a cylindrical side portion, and the housing 1 is arranged as shown in FIG. Figure 2-3 The winding core 2 shown has a positive pole tab 201 and a negative pole tab 202 at both ends of the winding core 2, and a positive current collecting plate 3 and a negative current collecting plate 4 respectively connected to the positive pole tab 201 and the negative pole tab 202 are arranged at both ends of the winding core 2, and a positive cover assembly 5 and a negative cover assembly 6 respectively connected to the positive current collecting plate 3 and the negative current collecting plate 4 are arranged at both ends of the outer shell 1.

[0035] The key improvement of this embodiment is that Figure 4-5As shown, the positive pole tab 201 and the negative pole tab 202 at both ends of the winding core 2 pass through the positive current collecting disk 3 and the negative current collecting disk 4 respectively, and are attached to the surfaces of the positive current collecting disk 3 and the negative current collecting disk 4. In the implementation manner of the present embodiment, a plurality of hollow grooves 7 are provided on the positive current collecting disk 3 and the negative current collecting disk 4 for the positive pole tab 201 and the negative pole tab 202 to pass through, and the positive pole tab 201 and the negative pole tab 202 are attached to the surfaces of the positive current collecting disk 3 and the negative current collecting disk 4 respectively, and the combination of the plurality of hollow grooves 7 presents a ring shape as a whole. Specifically, the plurality of hollow grooves 7 are arranged at equal intervals around the axis of the positive current collecting disk 3 or the negative current collecting disk 4, such as Figure 6-7 As shown, the positive electrode tab 201 and the negative electrode tab 202 passing through the hollow groove 7 fall down toward the axis of the positive electrode current collecting disc 3 or the negative electrode current collecting disc 4 .

[0036] In the implementation of the present embodiment, the several hollow grooves 7 on the negative electrode current collector 4 are divided into at least two groups according to the distance between them and the axis of the negative electrode current collector 4, that is, the several hollow grooves 7 are combined to present at least two rings, and the hollow grooves 7 in the outer layer have a longer extension length along the arc where they are located than the hollow grooves 7 in the inner layer; the several hollow grooves 7 on the positive electrode current collector 3 have a group according to the distance between them and the axis of the negative electrode current collector 4, that is, the several hollow grooves 7 are combined to present at least one ring, and in addition, there is a gap between the edge of the positive electrode current collector 3 and the inner side wall of the shell 1 for the positive electrode ear 201 to pass through to form a second group of positive electrode ears 201, wherein the diameter of the positive electrode current collector 3 is smaller than the diameter of the inner side wall of the shell 1, thereby forming the gap. This kind of positive electrode structure makes it easier to assemble the positive electrode current collector 3. The number of each group of hollow grooves 7 is at least 3.

[0037] During the implementation process, it was found that although the tab passes through the collector plate and then connects the collector plate to the pole on the cover assembly, it can improve the energy density of the battery, reduce the generation of welding slag, and more conveniently clean the welding slag, reduce the residual welding slag, and thus improve the safety performance of the battery, but because the tab has a certain thickness when it is bent and attached to the collector plate, the thickness of the tab after being flattened on the collector plate will affect the welding of the collector plate and the pole. For this reason, Figure 1 , 4 , 5, 11, and 12, a boss connected to the positive electrode cover assembly 5 is provided at the center of the positive electrode collector disc 3 in this embodiment, and the boss can prevent the thickness of the positive electrode tab 201 after being flattened on the positive electrode collector disc 3 from affecting the welding of the positive electrode collector disc 3 and the positive electrode cover assembly 5, and the edge of the negative electrode collector disc 4 is bent toward the negative electrode cover assembly 6 to form a peripheral portion 401 connected to the negative electrode cover assembly 6, thereby preventing the negative electrode tab 202 from affecting the normal connection between the negative electrode collector disc 4 and the negative electrode cover assembly 6. This structural design can ensure the normal transmission of battery current and improve the overall structural stability of the battery.

[0038] As an optimized implementation, the positive electrode cover assembly 5 includes a positive electrode cover plate 501 and a positive terminal 502 connected to the positive electrode cover plate 501. The positive terminal 502 protrudes toward the winding core 2 relative to the positive electrode cover plate 501 to connect to the boss, thereby further ensuring the connection between the positive current collecting plate 3 and the positive terminal 502. In addition, the outer end of the positive terminal 502 has a recessed portion 503 that penetrates deep into the interior of the outer shell 1.

[0039] In order to enhance the stability of the connection between the negative electrode current collecting disk 4 and the negative electrode cover assembly 6, a peripheral portion 401 of the negative electrode current collecting disk 4 is provided with a plurality of notches 402 at equal intervals around its axis. The negative electrode cover assembly 6 comprises a negative electrode cover plate. The connection of the negative electrode cover plate can be designed as a corrugated structure in conjunction with the notches 402, thereby enhancing the connection stability. In addition, a liquid injection hole 403 is provided in the center of the negative electrode current collecting disk 4.

[0040] In a possible embodiment, the depression depth is 3-10mm, the depression area is circular in shape, with a diameter of 4-8mm, the lower surface of the depression area penetrates deep into the shell 1, the entire positive terminal 502 is firmly embedded in one end of the shell 1, 1-3mm higher than the surface of the shell 1, the other end of the shell 1 is open, the diameter of the shell 1 is 32-46, preferably 32 or 46, and the thickness of the shell 1 is 0.3-0.8mm; the negative cover plate is circular, with a diameter the same as the outer ring diameter of the shell 1, an edge higher than 1-2mm, and an overall corrugated design to facilitate the stable connection of the negative cover plate, and an injection hole 403 is set in the center of the negative cover plate corresponding to the negative current collecting plate 4, and the size of the injection hole 403 is 2-4mm.

[0041] In this embodiment, through the structural design of the positive electrode collector plate 3 and the negative electrode collector plate 4, the pole ear is passed through the hollow groove 7 during the battery assembly process, and then the pole ear and the collector plate are connected, which can change the relative arrangement of the collector plate and the pole ear. This structure can improve the energy density of the battery, reduce the generation of welding slag, and can also more conveniently clean the welding slag and reduce the residual welding slag, thereby improving the safety performance of the battery. In addition, the positive electrode cover assembly 5 and the negative electrode cover assembly 6 are also correspondingly optimized in structure, which can ensure the normal transmission of the battery current and improve the overall structural stability of the battery.

[0042] Example 2

[0043] In this embodiment, the structural design of the positive electrode tab 201 and the positive electrode current collecting disk 3 is changed on the basis of the embodiment 1. Specifically, in this embodiment, the plurality of hollow grooves 7 on the negative electrode current collecting disk 4 are divided into at least two groups according to the distance between them and the axis of the negative electrode current collecting disk 4, and the hollow grooves 7 in the outer layer have a longer extension length along the arc where they are located than the hollow grooves 7 in the inner layer; similarly, Figure 8-10As shown, the several hollow grooves 7 on the positive electrode current collecting disk 3 are also divided into at least two groups according to the distance between them and the axis line of the positive electrode current collecting disk 3. The extension length of the hollow grooves 7 in the outer layer along the arc is longer than that of the hollow grooves 7 in the inner layer, and the corresponding positive electrode ears 201 of the winding core 2 are also changed accordingly.

[0044] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "inside" and "outside" are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0045] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" 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 it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] The protection scope of the present invention is limited only by the claims. Thanks to the teachings of the present invention, those skilled in the art will easily recognize that alternative structures to the structures disclosed in the present invention can be used as feasible alternative embodiments, and the embodiments disclosed in the present invention can be combined to generate new embodiments, which also fall within the scope of the appended claims.

Claims

1. A cylindrical battery, comprising at least a housing (1), a winding core (2), a positive electrode current collecting disc (3) and a negative electrode current collecting disc (4), and a positive electrode cover assembly (5) and a negative electrode cover assembly (6) arranged at both ends of the housing (1), characterized in that: The positive electrode tab (201) and the negative electrode tab (202) at both ends of the winding core (2) pass through the positive electrode collector disk (3) and the negative electrode collector disk (4) respectively, and are attached to the surfaces of the positive electrode collector disk (3) and the negative electrode collector disk (4); a boss (301) connected to the positive electrode cover assembly (5) is provided at the center of the positive electrode collector disk (3); and the edge of the negative electrode collector disk (4) is bent toward the negative electrode cover assembly (6) to form a peripheral portion (401) connected to the negative electrode cover assembly (6).

2. The cylindrical battery according to claim 1, characterized in that: The positive electrode current collector disk (3) and the negative electrode current collector disk (4) are provided with a plurality of hollow grooves (7) in a ring-shaped combination, and the plurality of hollow grooves (7) are arranged at equal intervals around the axis of the positive electrode current collector disk (3) or the negative electrode current collector disk (4), and the positive electrode tabs (201) and the negative electrode tabs (202) passing through the hollow grooves (7) fall toward the axis of the positive electrode current collector disk (3) or the negative electrode current collector disk (4).

3. The cylindrical battery according to claim 2, characterized in that: The plurality of hollow grooves (7) on the negative electrode current collecting disc (4) are divided into at least two groups according to the distance between the hollow grooves (7) and the axis of the negative electrode current collecting disc (4), and the hollow grooves (7) in the outer layer have a longer extension length along the arc where they are located than the hollow grooves (7) in the inner layer.

4. The cylindrical battery according to claim 3, characterized in that: There is a gap between the edge of the positive electrode current collecting disk (3) and the inner wall of the outer shell (1), for allowing the positive electrode tab (201) to pass through.

5. The cylindrical battery according to claim 3, characterized in that: The plurality of hollow grooves (7) on the positive electrode current collecting disk (3) are divided into at least two groups according to the distance between the hollow grooves (7) and the axis of the positive electrode current collecting disk (3), and the hollow grooves (7) in the outer layer have a longer extension length along the arc in which they are located than the hollow grooves (7) in the inner layer.

6. The cylindrical battery according to claim 5, characterized in that: The number of the hollow grooves (7) in each group is at least 3.

7. The cylindrical battery according to claim 1, characterized in that: The positive electrode cover assembly (5) comprises a positive electrode cover plate (501) and a positive electrode terminal (502) connected to the positive electrode cover plate (501); the positive electrode terminal (502) protrudes relative to the positive electrode cover plate (501) toward the winding core (2) to connect to the boss (301).

8. The cylindrical battery according to claim 7, characterized in that: The outer end of the positive terminal (502) has a recessed portion (503) extending deep into the interior of the housing (1).

9. The cylindrical battery according to any one of claims 1 to 8, characterized in that: The peripheral portion (401) of the negative electrode current collecting disk (4) is provided with a plurality of notches (402) at equal intervals around its axis.

10. The cylindrical battery according to claim 9, characterized in that: A liquid injection hole (403) is provided at the center of the negative electrode current collecting disk (4).

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