Cylindrical battery and battery pack

Abstract

The utility model belongs to the technical field of batteries, and discloses a cylindrical battery and a battery pack. The cylindrical battery comprises a shell and a pole group, and a positive terminal is arranged at the center of one end of the shell in an insulated and sealed manner; a positive pole lug and a negative pole lug are arranged at one end of the pole group, the positive pole lug is arranged at the position, close to the inner circumference, of the pole group, and the positive pole lug is electrically connected to the positive terminal; the negative electrode tabs are arranged on the periphery of the positive electrode tab at intervals in an insulating manner; and the negative tab is electrically connected to the shell, so that the cylindrical battery takes the positive terminal as an external positive electrode and the shell as an external negative electrode. According to the cylindrical battery, the volume utilization rate of the cylindrical battery is improved, the utilization rate of an active material is increased, and the energy density of the cylindrical battery is improved.

Description

Technical Field

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

[0002] With the rapid development of the electric vehicle industry, automakers are increasingly demanding long-range batteries, driving the development of high-energy-density lithium-ion batteries. Large cylindrical batteries offer significant advantages in terms of high energy density and safety.

[0003] To further improve the mass energy density of large cylindrical batteries, it is necessary to improve the utilization rate of active materials. Currently, the positive and negative tabs of large cylindrical batteries are often placed on both sides of the electrode group. This not only prolongs the electron transfer path and increases the battery impedance, but also reduces the height of the electrode group itself because the structural components connecting the positive and negative tabs occupy more space on different sides, thereby reducing the utilization rate of active materials and affecting the mass energy density of the cylindrical battery.

[0004] Therefore, there is an urgent need for a cylindrical battery and a battery pack to solve the above technical problems. Utility Model Content

[0005] One purpose of the present utility model is to provide a cylindrical battery and a battery pack, which improve the volume utilization rate of the cylindrical battery, increase the utilization rate of the active material, and improve the energy density of the cylindrical battery.

[0006] To achieve this purpose, the present invention adopts the following technical solutions:

[0007] Cylindrical batteries, including:

[0008] A housing, wherein a positive terminal is provided at the center of one end of the housing in an insulated and sealed manner;

[0009] An electrode group, wherein a positive electrode tab and a negative electrode tab are provided at one end of the electrode group, the positive electrode tab is arranged near the inner periphery of the electrode group, and the positive electrode tab is electrically connected to the positive terminal; the negative electrode tab is spaced and insulated and arranged on the outer periphery of the positive electrode tab; and the negative electrode tab is electrically connected to the outer shell.

[0010] Optionally, the electrode group is formed by winding a positive electrode sheet, a negative electrode sheet and a plurality of separators, and the separator is coated on the positive electrode sheet and / or the negative electrode sheet to insulate the positive electrode sheet and / or the negative electrode sheet.

[0011] Optionally, the positive electrode tab is arranged at one end of the positive electrode sheet and close to the winding core of the electrode group, so that the positive electrode tab can be arranged at a position close to the inner periphery of the electrode group, and the negative electrode tab is arranged at one end of the negative electrode sheet and close to the winding tail of the electrode group, so that the negative electrode tab can be arranged at a position close to the outer periphery of the electrode group and spaced apart from the positive electrode tab.

[0012] Optionally, a center hole is opened at one end of the shell, the positive terminal is arranged at the center hole, and an insulating seal is provided between the positive terminal and the hole wall of the center hole.

[0013] Optionally, an annular insulating member is further provided on the outer periphery of the positive terminal close to the electrode group, and the annular insulating member is arranged between the positive electrode tab and the negative electrode tab to insulate the negative electrode tab from the positive electrode tab.

[0014] Optionally, the cylindrical battery further includes a positive electrode current collecting disk, and the positive electrode current collecting disk is used to electrically connect the positive electrode tab and the positive terminal;

[0015] The cylindrical battery further includes a negative electrode current collecting plate, which is used to electrically connect the negative electrode tab and the housing.

[0016] Optionally, a pole is provided on a side of the positive current collecting disk away from the positive electrode ear, a mounting hole is provided on the positive terminal, and the pole is sealed and passed through the mounting hole and fixedly connected to the positive terminal.

[0017] Optionally, the positive electrode current collecting disc and the positive electrode tab are connected by laser penetration welding; and / or,

[0018] The negative electrode current collecting disc and the negative electrode tab are connected by laser penetration welding; and / or,

[0019] The negative electrode current collecting disc and the housing are connected by laser penetration welding; and / or,

[0020] The positive electrode current collecting disc and the positive electrode terminal are connected by welding through a tailor-made welding process.

[0021] Optionally, the housing includes:

[0022] A housing having a first end and a second end opposite to each other, the first end being provided with the positive terminal in an insulated and sealed manner, and the second end being provided with an opening for mounting the electrode group;

[0023] A cover plate is sealed and connected to the opening.

[0024] Another object of the present invention is to provide a battery pack, comprising the cylindrical battery described in any of the above schemes, which can improve the volume utilization of the battery pack, increase the utilization of active materials, and improve the energy density of the battery pack.

[0025] Beneficial effects of the utility model:

[0026] The utility model provides a cylindrical battery and battery pack, which are formed by arranging the positive and negative electrode tabs of the electrode group on the same side, and at the same time arranging a positive terminal on the same side as the positive electrode external connection terminal and electrically connected to the positive electrode tab, and electrically connecting the outer shell on the same side to the negative electrode tab as the negative electrode external connection terminal. This arrangement reduces the space for the tab on the other side of the electrode group and the accessories connected to the outer shell external connection terminal, improves the volume occupancy of the electrode group body, increases the utilization rate of the active material, and improves the energy density of the cylindrical battery. In addition, the positive and negative electrode tabs are arranged on the same side and adopt the form of inner and outer circumference rings, so that the positive and negative tabs can be welded simultaneously, simplifying the assembly process and reducing manufacturing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural diagram of a cylindrical battery provided by a specific embodiment of the utility model;

[0028] Figure 2 It is a structural diagram of the electrode group provided by a specific embodiment of the utility model;

[0029] Figure 3 It is a structural schematic diagram of the positive electrode sheet provided by a specific embodiment of the utility model;

[0030] Figure 4 It is a structural schematic diagram of the negative electrode sheet provided by a specific embodiment of the present utility model.

[0031] In the picture:

[0032] 10. Housing; 11. Positive terminal; 111. Mounting hole; 112. Overlapping portion; 12. Housing; 121. Opening; 13. Cover; 14. Insulating seal;

[0033] 20. Electrode group; 201. Positive electrode sheet; 202. Negative electrode sheet; 203. Winding core; 204. Winding tail; 21. Positive electrode tab; 22. Negative electrode tab; 23. Hollow cavity;

[0034] 30. Annular insulator; 40. Positive electrode current collecting disc; 41. Pole; 50. Negative electrode current collecting disc. DETAILED DESCRIPTION

[0035] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all of its components.

[0036] In the description of this utility model, unless otherwise specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; they can refer to direct connection or indirect connection through an intermediate medium; they can refer to internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0037] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0038] In the description of this embodiment, the terms "upper," "lower," "left," "right," and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They do not indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meaning.

[0039] Please refer to the attached Figure 1 To the attached Figure 4 The utility model introduces a cylindrical battery and a battery pack.

[0040] Please refer to Figure 1 and Figure 2This embodiment provides a cylindrical battery, which includes a shell 10 and an electrode group 20, wherein a positive terminal 11 is insulated and sealed at the center of one end of the shell 10; a positive electrode tab 21 and a negative electrode tab 22 are provided at one end of the electrode group 20, the positive electrode tab 21 is arranged near the inner periphery of the electrode group 20, and the positive electrode tab 21 is electrically connected to the positive terminal 11; the negative electrode tab 22 is spaced and insulated and arranged on the outer periphery of the positive electrode tab 21; the negative electrode tab 22 is electrically connected to the shell 10, so that the cylindrical battery has the positive terminal 11 as the external positive electrode and the shell 10 as the external negative electrode.

[0041] In the cylindrical battery of this embodiment, the positive electrode tab 21 and the negative electrode tab 22 of the electrode group 20 are arranged on the same side. At the same time, a positive terminal 11 is arranged on this side as the positive electrode external connection terminal and is electrically connected to the positive electrode tab 21. The outer shell 10 on the same side is electrically connected to the negative electrode tab 22 as the negative electrode external connection terminal to form a cylindrical battery. This arrangement reduces the space for the tab on the other side of the electrode group 20 and the accessories connected to the external connection terminal of the outer shell 10, improves the volume occupancy of the electrode group 20 body, increases the utilization rate of the active material, and improves the energy density of the cylindrical battery. In addition, the positive electrode tab 21 and the negative electrode tab 22 are arranged on the same side and adopt the form of inner and outer circumference rings, so that the positive and negative tabs can be welded simultaneously, simplifying the assembly process and reducing manufacturing costs.

[0042] Please refer to Figure 1 In some embodiments, the housing 10 includes a shell 12 and a cover 13. The shell 12 has a first end and a second end that are oppositely disposed. The first end is provided with a positive terminal 11 in an insulated and sealed manner, and the second end is provided with an opening 121 for mounting the electrode group 20. The cover 13 is sealed and connected to the opening 121. During installation, one end of the electrode group 20 having the positive electrode tab 21 and the negative electrode tab 22 is installed in the shell 12 through the opening 121. Then, electrical connections are made between the positive electrode tab 21 and the positive terminal 11, and between the negative electrode tab 22 and the shell 10. After the installation and connection are completed, the cover 13 is sealed and connected to the shell 12, and the corresponding electrolyte is injected to complete the installation of the cylindrical battery.

[0043] Specifically, a center hole is opened at one end of the shell 10, specifically, a center hole is opened at the first end of the shell 12, the positive terminal 11 is arranged at the center hole, and an insulating seal 14 is provided between the positive terminal 11 and the hole wall of the center hole. The insulating seal 14 can realize the insulating and sealed connection between the positive terminal 11 and the shell 10.

[0044] Specifically, an annular insulating member 30 is further provided on the outer periphery of the positive terminal 11 close to the electrode group 20. The annular insulating member 30 is arranged between the positive electrode tab 21 and the negative electrode tab 22 to insulate the negative electrode tab 22 from the positive electrode tab 21. At the same time, it also ensures the insulation between the side of the positive terminal 11 close to the electrode group 20 and the negative electrode tab 22.

[0045] More specifically, a lap portion 112 is provided on one side of the positive terminal 11 close to the electrode group 20 for supporting the annular insulating member 30 , so that the annular insulating member 30 is provided on the lap portion 112 .

[0046] Optionally, the annular insulating member 30 and the insulating seal 14 are arranged in contact so that the outer periphery of the positive terminal 11 is provided with an insulating structure, so that the positive terminal 11 and the shell 12, as well as the positive terminal 11 and the negative electrode tab 22 are all insulated, thereby improving the safety of the cylindrical battery.

[0047] In some embodiments, the electrode assembly 20 is formed by winding a positive electrode sheet 201, a negative electrode sheet 202, and a plurality of separators. The separators are coated on the positive electrode sheet 201 and / or the negative electrode sheet 202 to insulate the positive electrode sheet 201 and / or the negative electrode sheet 202. The winding molding process is relatively mature and has high processing efficiency and precision.

[0048] It should be noted that the positive electrode sheet 201 is usually formed by processing an aluminum foil material, and the negative electrode sheet 202 is usually formed by processing an copper foil material.

[0049] Specifically, the electrode assembly 20 is stacked from the inside out through the separator, positive electrode sheet 201, separator, negative electrode sheet 202, and separator, and then wound. The joint at the center of the wound electrode assembly 20 is the winding core 203, and the joint at the periphery of the wound electrode assembly 20 is the winding tail 204, thus completing the winding formation of the electrode assembly 20. Furthermore, the interior of the winding core 203 is hollow, forming the hollow cavity 23 of the electrode assembly 20, which facilitates subsequent welding, liquid injection, and venting.

[0050] More specifically, after the electrode group 20 is wound and formed, the positive electrode tab 21 and the negative electrode tab 22 need to be shaped and formed into the positive electrode tab 21 and the negative electrode tab 22 through a flattening process in a multi-layer current collecting sheet stacked state.

[0051] Optionally, after the positive electrode tab 21 and the negative electrode tab 22 are formed, the height of the positive electrode tab 21 is 2mm-3mm, and the outer diameter is 26±0.5mm; the height of the negative electrode tab 22 is 3mm-4mm, the outer diameter is 40±0.5mm, and the inner diameter is 30±0.5mm, which meets the processing requirements of most types of cylindrical batteries. During processing, it is only necessary to select within the above range.

[0052] Please refer to Figure 3 and Figure 4Specifically, the positive electrode tab 21 is disposed at one end of the positive electrode sheet 201 and near the winding core 203 of the electrode assembly 20, so that the positive electrode tab 21 can be disposed near the inner periphery of the electrode assembly 20. The negative electrode tab 22 is disposed at one end of the negative electrode sheet 202 and near the winding tail 204 of the electrode assembly 20, so that the negative electrode tab 22 can be disposed near the outer periphery of the electrode assembly 20 and spaced apart from the positive electrode tab 21. With this arrangement, after the electrode assembly 20 is wound, the positive electrode tab 21 is formed near the inner periphery of the electrode assembly 20, and the negative electrode tab 22 is formed near the outer periphery of the electrode assembly 20, so that the two tabs are spaced apart and do not interfere with each other.

[0053] Optionally, the positive electrode tab 21 and the negative electrode tab 22 are formed by removing excess parts from the positive electrode sheet 201 using a die-cutting process, so that the positive electrode tab 21 is arranged at one end of the positive electrode sheet 201 and close to the winding core 203 of the electrode group 20, and the negative electrode tab 22 is arranged at one end of the negative electrode sheet 202 and close to the winding tail 204 of the electrode group 20.

[0054] Please refer to Figure 1 In some embodiments, the cylindrical battery further includes a positive electrode current collecting disc 40, which is used to electrically connect the positive electrode tab 21 and the positive terminal 11; one end of the positive electrode current collecting disc 40 is connected to the positive electrode tab 21, and the other end is connected to the positive terminal 11, so that the positive electrode current collecting disc 40 can be used to electrically connect the positive electrode tab 21 and the positive terminal 11.

[0055] Specifically, a post 41 is provided on the side of the positive current collecting disc 40 away from the positive electrode tab 21. A mounting hole 111 is provided in the positive electrode terminal 11. The post 41 is sealedly inserted through the mounting hole 111 and fixedly connected to the positive electrode terminal 11, thereby achieving a better fixed connection between the two. During installation, the post 41 and the mounting hole 111 can first be used to position the entire electrode assembly 20 and the housing 10, and then the corresponding positions can be fixedly connected.

[0056] Optionally, the positive electrode current collecting disc 40 has a thickness of 0.5 mm to 0.6 mm and an outer diameter of 26 ± 0.5 mm, which can achieve the function of electrically connecting the positive electrode terminal 11 and the positive electrode tab 21. At the same time, it will not contact other structures of the electrode assembly 20, thus avoiding the problem of short circuit in the cylindrical battery, making the cylindrical battery more reliable.

[0057] In some embodiments, the cylindrical battery further includes a negative electrode current collecting plate 50, which is used to electrically connect the negative electrode tab 22 and the outer shell 10; one end of the negative electrode current collecting plate 50 is connected to the negative electrode tab 22, and the other end is connected to the outer shell 10, so that the negative electrode current collecting plate 50 can be used to electrically connect the negative electrode tab 22 and the outer shell 10.

[0058] Optionally, the negative electrode current collecting disc 50 has a thickness of 0.5 mm to 0.6 mm, an outer diameter of 39 ± 0.5 mm, and an inner diameter of 31 ± 0.5 mm. This allows the negative electrode current collecting disc 50 to electrically connect the housing 10 and the negative electrode tab 22. Furthermore, the negative electrode current collecting disc 50 does not contact other structures of the electrode assembly 20, thereby preventing short circuits in the cylindrical battery and making the cylindrical battery more reliable.

[0059] In some embodiments, the positive current collecting plate 40 and the positive electrode tab 21, the negative current collecting plate 50 and the negative electrode tab 22, the negative current collecting plate 50 and the outer shell 10 and / or the positive current collecting plate 40 and the positive terminal 11 are connected by a welding process, which has a good fixing effect and a certain sealing performance.

[0060] Specifically, the positive electrode current collecting disc 40 and the positive electrode tab 21 are welded together by a laser penetration welding process; and / or, the negative electrode current collecting disc 50 and the negative electrode tab 22 are welded together by a laser penetration welding process; and / or, the negative electrode current collecting disc 50 and the outer shell 10 are welded together by a laser penetration welding process; and / or, the positive electrode current collecting disc 40 and the positive terminal 11 are welded together by a tailor welding process, so as to better achieve fixed connection at each position and better welding effect.

[0061] This embodiment further provides a battery pack comprising the cylindrical battery described in any of the above solutions. The battery pack uses the above cylindrical battery, thereby improving the energy density and volume utilization of the battery pack.

[0062] Obviously, the above-described embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the manner in which the present invention is to be implemented. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. Cylindrical battery, characterized in that, include: A housing, wherein a positive terminal is provided at the center of one end of the housing in an insulated and sealed manner; An electrode group, wherein a positive electrode tab and a negative electrode tab are provided at one end of the electrode group, the positive electrode tab is arranged near the inner periphery of the electrode group, and the positive electrode tab is electrically connected to the positive terminal; the negative electrode tab is spaced and insulated and arranged on the outer periphery of the positive electrode tab; and the negative electrode tab is electrically connected to the outer shell.

2. The cylindrical battery according to claim 1, characterized in that: The electrode group is formed by winding a positive electrode sheet, a negative electrode sheet and a plurality of separators, and the separator is coated on the positive electrode sheet and / or the negative electrode sheet to insulate the positive electrode sheet and / or the negative electrode sheet.

3. The cylindrical battery according to claim 2, characterized in that: The positive electrode tab is arranged at one end of the positive electrode sheet and close to the winding core of the electrode group, so that the positive electrode tab can be arranged near the inner periphery of the electrode group. The negative electrode tab is arranged at one end of the negative electrode sheet and close to the winding tail of the electrode group, so that the negative electrode tab can be arranged near the outer periphery of the electrode group and spaced apart from the positive electrode tab.

4. The cylindrical battery according to claim 1, characterized in that A central hole is opened at one end of the shell, the positive terminal is arranged at the central hole, and an insulating seal is provided between the positive terminal and the hole wall of the central hole.

5. The cylindrical battery according to claim 1, characterized in that: An annular insulating member is further provided on the outer periphery of the positive terminal close to the electrode group. The annular insulating member is arranged between the positive electrode tab and the negative electrode tab to insulate the negative electrode tab from the positive electrode tab.

6. The cylindrical battery according to claim 1, characterized in that The cylindrical battery further includes a positive electrode current collecting plate, which is used to electrically connect the positive electrode tab and the positive terminal; The cylindrical battery further includes a negative electrode current collecting plate, which is used to electrically connect the negative electrode tab and the housing.

7. The cylindrical battery according to claim 6, characterized in that: A pole is provided on a side of the positive electrode current collecting disk away from the positive electrode tab. A mounting hole is provided in the positive electrode terminal. The pole is sealed and passed through the mounting hole and is fixedly connected to the positive electrode terminal.

8. The cylindrical battery according to claim 6, characterized in that: The positive electrode current collecting disc and the positive electrode tab are welded together by laser penetration welding; and / or, The negative electrode current collecting plate and the negative electrode tab are welded together by laser penetration welding; and / or, The negative electrode current collecting disc and the housing are welded together by laser penetration welding; and / or, The positive electrode current collecting plate and the positive electrode terminal are connected by welding through a tailor-made welding process.

9. The cylindrical battery according to any one of claims 1 to 8, characterized in that: The housing comprises: a housing having a first end and a second end opposite to each other, the first end being provided with the positive terminal in an insulated and sealed manner, and the second end being provided with an opening for mounting the electrode group; A cover plate is sealed and connected to the opening.

10. A battery pack, characterized in that: The invention comprises a cylindrical battery as claimed in any one of claims 1 to 9.

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