Cylindrical battery

Abstract

The utility model relates to the technical field of batteries, and discloses a cylindrical battery. The cylindrical battery comprises a battery shell, a battery cell and a first current collecting piece, the battery shell comprises a cover plate; the battery cell is arranged in the battery shell and comprises a first tab; the first current collector is arranged between the cover plate and the battery cell, the first current collector is provided with a cover plate welding area and a first tab welding area, the cover plate welding area is connected with the cover plate, and the first tab welding area is connected with the first tab; the ratio of the radius of the cover plate to the radius of the first current collecting piece is larger than or equal to 1 and smaller than or equal to 1.5. According to the cylindrical battery, the area of the cover plate welding area and the area of the first tab welding area are ensured to be sufficient, namely, the requirement of the welding area of the first current collecting piece and the first tab and the requirement of the welding area of the first current collecting piece and the cover plate are met, and the overflowing area is not influenced; and the cover plate is prevented from slipping off from the jig, so that the concentric positioning precision between the cover plate and the first current collecting piece is ensured.

Description

Technical Field

[0001] The present disclosure relates to the field of battery technology, and in particular to a cylindrical battery. Background Art

[0002] When assembling the cylindrical battery, in order to ensure the concentricity of the cover plate and the first current collector, the cover plate and the first current collector are positioned using the same fixture, that is, one set, to avoid using two sets of fixtures to reduce positioning accuracy.

[0003] However, during the assembly of current cylindrical batteries, the cover plate is easily slipped off the jig, resulting in a decrease in the concentricity accuracy between the cover plate and the first current collector; or, the welding area requirements between the first current collector and the first pole ear cannot be met; or, the welding area requirements between the first current collector and the cover plate cannot be met.

[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Utility Model Content

[0005] The purpose of the present disclosure is to overcome the deficiencies of the above-mentioned related technologies and provide a cylindrical battery.

[0006] According to one aspect of the present disclosure, there is provided a cylindrical battery, comprising:

[0007] Battery housing, including cover;

[0008] The battery cell is arranged in the battery housing, and the battery cell comprises a first pole ear;

[0009] A first current collector is provided between the cover plate and the battery cell, the first current collector having a cover plate welding area and a first pole lug welding area, the cover plate welding area is connected to the cover plate, and the first pole lug welding area is connected to the first pole lug;

[0010] Wherein, the ratio of the radius of the cover plate to the radius of the first current collecting member is greater than or equal to 1 and less than or equal to 1.5.

[0011] In the cylindrical battery disclosed in the present invention, the ratio of the radius of the cover plate to the radius of the first current collector is greater than or equal to 1 and less than or equal to 1.5, which not only ensures that the area of ​​the cover plate welding area and the area of ​​the first pole lug are sufficient, that is, the requirements for the welding area between the first current collector and the first pole lug and the requirements for the welding area between the first current collector and the cover plate are met, and the flow area will not be affected; it also ensures that the cover plate will not slip off the fixture, thereby ensuring the concentric positioning accuracy between the cover plate and the first current collector.

[0012] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification are used to explain the principles of the present disclosure. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0014] Figure 1 It is a schematic structural diagram of an exemplary embodiment of a cylindrical battery disclosed in the present invention.

[0015] Figure 2 for Figure 1 Schematic diagram of a partial cross-section of a medium cylindrical battery.

[0016] Figure 3 for Figure 1 Schematic diagram of the structure of the first current collecting component.

[0017] Figure 4 for Figure 1 Schematic diagram of the structure of the second current collecting member.

[0018] Description of reference numerals:

[0019] 1. Battery housing; 11. Cover plate; 12. Side wall; 13. Bottom wall;

[0020] 2. battery cell; 21. first pole ear; 22. second pole ear; 23. main body;

[0021] 3. First current collector; 31. Connecting ring; 31a. Cover plate welding area; 32. Connecting tube; 33. Connecting plate; 33a. First pole ear welding area; 34. Arc portion;

[0022] 4. Support part;

[0023] 5. Second current collecting member; 51. First current collecting portion; 51a. Second electrode tab welding area; 52. Second current collecting portion;

[0024] 6. Battery pole;

[0025] X, axial; Y, radial. DETAILED DESCRIPTION

[0026] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present disclosure will be comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their detailed description will be omitted. In addition, the drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale.

[0027] Although relative terms such as "upper" and "lower" are used in this specification to describe the relative relationship of one component of the illustration to another component, these terms are used in this specification only for convenience, such as according to the orientation of the examples described in the drawings. It is understood that if the device of the illustration is turned upside down, the component described as "upper" will become the component "lower". When a structure is "on" other structures, it may mean that the structure is formed integrally on the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure through another structure.

[0028] The terms "a", "an", "the", "said" and "at least one" are used to indicate the presence of one or more elements / components / etc.; the terms "including" and "having" are used to express an open-ended inclusive meaning and mean that additional elements / components / etc. may exist in addition to the listed elements / components / etc.; the terms "first", "second" and "third" etc. are used merely as labels and are not intended to limit the quantity of their objects.

[0029] In this application, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. "And / or" is just a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the previous and next associated objects are in an "or" relationship.

[0030] The exemplary embodiment of the present disclosure provides a cylindrical battery, referring to Figure 1-Figure 4As shown, the cylindrical battery may include a battery housing 1, a battery cell 2 and a first current collector 3; the battery housing 1 may include a cover plate 11; the battery cell 2 is arranged in the battery housing 1, and the battery cell 2 may include a first pole tab 21; the first current collector 3 is arranged between the cover plate 11 and the battery cell 2, and the first current collector 3 has a cover plate welding area 31a and a first pole tab welding area 33a, the cover plate welding area 31a is connected to the cover plate 11, and the first pole tab welding area 33a is connected to the first pole tab 21; wherein, the ratio of the radius of the cover plate 11 to the radius of the first current collector 3 is greater than or equal to 1 and less than or equal to 1.5.

[0031] The cylindrical battery disclosed in the present invention not only ensures that the area of ​​the cover plate welding area 31a and the area of ​​the first pole lug welding area 33a are sufficient, that is, the requirements of the welding area between the first current collector 3 and the first pole lug 21 and the welding area between the first current collector 3 and the cover plate 11 are met, and the flow area will not be affected; it also ensures that the cover plate 11 will not slip off the fixture, thereby ensuring the concentric positioning accuracy between the cover plate 11 and the first current collector 3.

[0032] In this example implementation, refer to Figure 1 As shown, the battery housing 1 can be configured as a cylinder, that is, the battery housing 1 can include a cover plate 11 and a bottom wall 13 that are arranged opposite to each other, the cover plate 11 and the bottom wall 13 are both arranged in a circular shape, and a side wall 12 is connected between the cover plate 11 and the bottom wall 13, and the side wall 12 is arranged in a cylindrical shape. The side wall 12, the cover plate 11 and the bottom wall 13 surround and form a battery accommodating cavity.

[0033] The battery housing 1 may be made of aluminum, steel or other metals and alloys. Of course, it may also be made of other materials, which will not be described here one by one.

[0034] In this example implementation, refer to Figure 2 As shown, a battery cell 2 is arranged in the accommodating cavity of the battery housing 1. The battery cell 2 may include a main body 23, a first pole ear 21 and a second pole ear 22. The main body 23 may be arranged as a cylinder adapted to the battery housing 1. The main body 23 may include a first pole piece and a second pole piece (not shown in the figure), and a separation film arranged between the first pole piece and the second pole piece. The main body 23 may be formed by winding the first pole piece, the separation film and the second pole piece arranged in layers. Active material is coated on the first pole piece and the second pole piece.

[0035] The first pole tab 21 is connected to the main body 23, specifically, the first pole tab 21 is connected to the first pole piece; the first pole tab 21 is located on the side of the main body 23 close to the cover plate 11. The second pole tab 22 is connected to the main body 23, specifically, the second pole tab 22 is connected to the second pole piece; and the second pole tab 22 can be located on the same side of the main body 23 as the first pole tab 21, that is, the second pole tab 22 can be located on the side of the main body 23 close to the cover plate 11, that is, the second pole tab 22 and the first pole tab 21 are located on the same end surface of the battery cell 2.

[0036] Of course, in some other exemplary embodiments of the present disclosure, the second electrode tab 22 and the first electrode tab 21 may be located on opposite sides of the main body 23 , that is, the second electrode tab 22 may be located on one side of the main body 23 close to the bottom wall 13 .

[0037] The first pole tab 21 may be a portion of the multi-layer first pole sheet extending out of the main body 23, and being bent to the side of the first end face of the main body 23 away from the main body 23 to form the first pole tab 21, so that the first pole tab 21 may include a multi-layer first pole tab sheet. The second pole tab 22 may be a portion of the multi-layer second pole sheet extending out of the main body 23, and being bent to the side of the first end face of the main body 23 away from the main body 23 to form the second pole tab 22, so that the second pole tab 22 may include a multi-layer second pole tab sheet.

[0038] It should be noted that the first pole tab 21 and the second pole tab 22 are conductive foil areas without active material coating, that is, no active material coating is coated on the first pole tab 21 and the second pole tab 22, and the first pole tab 21 and the second pole tab 22 are current collecting layers for transmitting current.

[0039] In this example implementation, refer to Figure 2 As shown, a first current collector 3 is provided on one side of the first pole tab 21 close to the cover plate 11, so that the first current collector 3 is provided between the cover plate 11 and the battery cell 2. The first current collector 3 has a cover plate welding area 31a and a first pole tab welding area 33a, the cover plate welding area 31a is connected to the cover plate 11, specifically, the cover plate welding area 31a is welded to the cover plate 11, so that a welding portion is provided between the cover plate welding area 31a and the cover plate 11; the first pole tab welding area 33a is connected to the first pole tab 21, specifically, the first pole tab welding area 33a is welded to the first pole tab 21, so that a welding portion is provided between the first pole tab welding area 33a and the first pole tab 21.

[0040] The first current collector 3 needs to be welded to both the first pole ear 21 and the cover plate 11; the welding of the first current collector 3 and the first pole ear 21 can be completed first, and then the welding of the first current collector 3 and the cover plate 11 is performed, so that the positioning accuracy of the first current collector 3 and the cover plate 11 is required to be high. If the positioning accuracy of the first current collector 3 and the cover plate 11 is low, after the first current collector 3 and the cover plate 11 are welded, a pulling force will be generated between the first pole ear 21, the first current collector 3 and the cover plate 11, which may easily lead to welding failure between the first pole ear 21 and the first current collector 3, and between the first current collector 3 and the cover plate 11.

[0041] In this example embodiment, the radius of the first current collecting part 3 is smaller than the radius of the cover plate 11, so that the outer peripheral surface of the first current collecting part 3 and the side of the cover plate 11 close to the first current collecting part 3 form a step, and the step cooperates with the step on the assembly jig to achieve the positioning of the first current collecting part 3 and the cover plate 11; for example, the jig has two steps, one step is used to overlap the first current collecting part 3, and the other step is used to overlap the cover plate 11.

[0042] The ratio of the radius of the cover plate 11 to the radius of the first current collecting part 3 is greater than or equal to 1 and less than or equal to 1.5. For example, the ratio of the radius of the cover plate 11 to the radius of the first current collecting part 3 can be 1.02, 1.04, 1.05, 1.06, 1.07, 1.08, 1.1, 1.12, 1.13, 1.15, 1.17, 1.19, 1.2, 1.22, 1.25, 1.27, 1.3, 1.33, 1.35, 1.38, 1.4, 1.42, 1.45, 1.47 and the like.

[0043] Generally, when the structure of the battery is fixed, the radius of the cover plate 11 is a constant; if the ratio of the radius of the cover plate 11 to the radius of the first current collector 3 is too large, the radius of the first current collector 3 is smaller, that is, the area of ​​the first current collector 3 is smaller. While ensuring the area of ​​the first pole lug welding area 33a, the area of ​​the cover plate welding area 31a is smaller, which affects the flow area between the first current collector 3 and the cover plate 11; conversely, if the area of ​​the first pole lug welding area 33a is smaller while ensuring the area of ​​the cover plate welding area 31a, the flow area between the first current collector 3 and the first pole lug 21 is affected.

[0044] If the ratio of the radius of the cover plate 11 to the radius of the first current collecting part 3 is too small, the radius of the first current collecting part 3 is larger and the difference between the radius of the cover plate 11 is smaller, the width of the step formed by the first current collecting part 3 and the cover plate 11 is too small, resulting in the overlapping width of the cover plate 11 being too narrow, and the cover plate 11 is easy to slip off the jig, resulting in a decrease in the concentric positioning accuracy between the cover plate 11 and the first current collecting part 3.

[0045] The above numerical range not only ensures that the area of ​​the cover plate welding area 31a and the area of ​​the first pole lug welding area 33a are sufficient, that is, the requirements of the welding area between the first current collector 3 and the first pole lug 21 and the welding area between the first current collector 3 and the cover plate 11 are met, and the flow area will not be affected; it also ensures that the cover plate 11 will not slip off the fixture, thereby ensuring the concentric positioning accuracy between the cover plate 11 and the first current collector 3.

[0046] Specifically, in some example embodiments of the present disclosure, the radius of the cover plate 11 is greater than or equal to 22.55 mm and less than or equal to 23.65 mm. For example, the radius of the cover plate 11 may be 22.6 mm, 22.65 mm, 22.7 mm, 22.75 mm, 22.8 mm, 22.85 mm, 22.9 mm, 22.95 mm, 23 mm, 23.05 mm, 23.1 mm, 23.15 mm, 23.2 mm, 23.25 mm, 23.3 mm, 23.35 mm, 23.4 mm, 23.45 mm, 23.5 mm, 23.55 mm, 23.6 mm, and the like; the radius of the first current collecting part 3 is greater than or equal to 21.7 mm and less than or equal to 21.8 mm. For example, the radius of the first current collecting part 3 may be 21.72 mm, 21.75 mm, 21.77 mm, and the like.

[0047] It should be noted that, when the outer cylindrical surface of the cover plate 11 is welded to the outer cylindrical surface of the side wall 12, the radius of the cover plate 11 may be the radius of the largest circle formed by the orthographic projection of the cover plate 11 on the first reference plane along the axial direction of the cylindrical battery. When the circular top surface of the cover plate 11 facing away from the bottom wall 13 is welded to the annular top surface of the side wall 12 facing away from the bottom wall 13, since the connection formed by welding connects the cover plate 11 and the side wall 12 to form an inseparable structure, and the thickness of the side wall 12 is relatively thin, so that the cover plate 11 extends to the outer cylindrical surface of the side wall 12, the radius of the cover plate 11 may be the radius of the largest circle formed by the orthographic projection of the top surface of the cover plate 11 on the first reference plane along the axial direction of the cylindrical battery.

[0048] The radius of the first current collector 3 may be the maximum distance between the outer contour of the orthographic projection of the first current collector 3 along the axial direction of the cylindrical battery on the first reference plane and the orthographic projection (a center point) of the central axis of the cylindrical battery on the first reference plane. The first reference plane is perpendicular to the axial direction of the cylindrical battery.

[0049] The first tab welding area 33a is connected to one side of the cap welding area 31a close to the central axis of the cylindrical battery, that is, the first tab welding area 33a is connected to the inner side of the cap welding area 31a.

[0050] In this example implementation, refer to Figure 2 and Figure 3As shown, the first current collecting member 3 may include a connecting ring 31, a connecting tube 32 and a connecting plate 33; the connecting ring 31 is configured in a circular ring shape, so that the connecting ring 31 has an inner ring surface and an outer ring surface. The connecting ring 31 may include a cover plate welding area 31a, a part of the connecting ring 31 may be the cover plate welding area 31a, or the entire connecting ring 31 may be the cover plate welding area 31a, and the connecting ring 31 may be welded to the cover plate 11.

[0051] It should be noted that the connecting ring 31 is not limited to a strict circular ring shape, and the outer contour of the connecting ring 31 can be approximately circular, and some recessed parts or protruding parts can be set on the connecting ring 31. The connecting ring 31 can also be discontinuous, that is, a disconnected part of a certain length can be set in the middle.

[0052] The connecting tube 32 is connected to a side of the connecting ring 31 close to the battery core 2 , and the connecting tube 32 is connected to the inner ring surface of the connecting ring 31 , so that the connecting ring 31 can overlap on the step of the fixture for positioning.

[0053] The connecting tube 32 is configured to be a semi-cylindrical shape, and the connecting tube 32 is smoothly transitionally connected to the connecting ring 31. Specifically, the connecting ring 31 and the connecting tube 32 are transitionally connected via an arc portion 34, and the center angle of the arc portion 34 is greater than or equal to 30° and less than or equal to 170°. For example, the center angle of the arc portion 34 can be 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85°, 90°, 95°, 100°, 105°, 110°, 115°, 120°, 125°, 130°, 135°, 140°, 145°, 150°, 155°, 160°, 165°, etc.

[0054] The size of the central angle of the arc portion 34 is the size of the included angle between the connecting ring 31 and the connecting tube 32 .

[0055] If the central angle of the arc portion 34 is too large, the angle between the connecting ring 31 and the connecting tube 32 will be too large, which will cause the connecting tube 32 to tilt seriously inward, resulting in the area of ​​the connecting plate 33 being too small, that is, the area of ​​the first pole ear welding area 33a is too small, affecting the flow area between the first current collector 3 and the first pole ear 21.

[0056] If the central angle of the arc portion 34 is too small, the angle between the connecting ring 31 and the connecting tube 32 will be too small, which will cause the connecting tube 32 to tilt seriously outward, resulting in no space for arranging the support portion 4.

[0057] The above numerical range not only ensures the area of ​​the first electrode tab welding area 33 a to ensure the flow area between the first current collector 3 and the first electrode tab 21 , but also ensures that there is space for arranging the support portion 4 .

[0058] The connection plate 33 is connected to the side of the connection tube 32 close to the battery cell 2, so that the height of the connection plate 33 is lower than the height of the connection ring 31; and the connection plate 33 is connected to the inner cylinder surface of the connection tube 32. The connection plate 33 is arranged in a fan ring shape, and the connection plate 33 may include a first pole lug welding area 33a, and a part of the connection plate 33 may be the first pole lug welding area 33a, or the entire connection plate 33 may be the first pole lug welding area 33a. The connection ring 31, the connection tube 32 and the connection plate 33 are arranged on the same central axis; and the connection plate 33 and the connection tube 32 are smoothly transitionally connected.

[0059] Of course, in some other exemplary embodiments of the present disclosure, the first current collecting member 3 may not include the connecting cylinder 32 , but only include the connecting ring 31 and the connecting plate 33 .

[0060] In this example embodiment, the ratio of the width of the connecting ring 31 to the radius of the cover plate 11 is greater than or equal to 0.01 and less than or equal to 0.5. For example, the ratio of the width of the connecting ring 31 to the radius of the cover plate 11 can be 0.05, 0.07, 0.1, 0.13, 0.15, 0.18, 0.2, 0.22, 0.25, 0.27, 0.3, 0.33, 0.35, 0.38, 0.4, 0.42, 0.45, 0.47, etc.

[0061] If the ratio of the width of the connecting ring 31 to the radius of the cover plate 11 is too large, the width of the connecting ring 31 is too large and the area of ​​the first pole tab welding area 33a is too small, which cannot meet the connection strength requirements and flow area requirements between the first pole tab 21 and the connecting plate 33.

[0062] If the ratio of the ring width of the connecting ring 31 to the radius of the cover plate 11 is too small, the ring width of the connecting ring 31 is too small, and the ring width of the cover plate welding area 31a is too small, which cannot meet the width requirement of the cover plate welding area 31a, and thus cannot meet the connection strength requirement and flow area requirement between the cover plate 11 and the connecting ring 31.

[0063] The above numerical range not only meets the connection strength requirement and the flow area requirement between the cover plate 11 and the connection ring 31 , but also meets the connection strength requirement and the flow area requirement between the first electrode tab 21 and the connection plate 33 .

[0064] Specifically, the width of the connecting ring 31 is greater than or equal to 0.5 mm and less than or equal to 5 mm. For example, the width of the connecting ring 31 can be 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 1.7 mm, 2 mm, 2.3 mm, 2.5 mm, 2.8 mm, 3 mm, 3.2 mm, 3.5 mm, 3.7 mm, 4 mm, 4.3 mm, 4.5 mm, 4.8 mm, etc.

[0065] If the width of the connecting ring 31 is too small, it cannot meet the width requirement of the cover plate welding area 31 a, and thus cannot meet the connection strength requirement and flow area requirement between the cover plate 11 and the connecting ring 31 .

[0066] If the width of the connecting ring 31 is too large, the area of ​​the first electrode tab welding region 33 a is too small, and the connection strength requirements and the flow area requirements between the first electrode tab 21 and the connecting plate 33 cannot be met.

[0067] The above numerical range not only meets the connection strength requirement and the flow area requirement between the cover plate 11 and the connection ring 31 , but also meets the connection strength requirement and the flow area requirement between the first electrode tab 21 and the connection plate 33 .

[0068] It should be noted that the ring width of the connecting ring 31 refers to the vertical distance between the inner ring surface of the connecting ring 31 and the outer ring surface of the connecting ring 31. When the connecting ring 31 is set as a circular ring, the ring width of the connecting ring 31 refers to the difference between the radius of the outer ring surface of the connecting ring 31 and the radius of the inner ring surface of the connecting ring 31.

[0069] In this example embodiment, the distance between the outer edge of the first current collecting part 3 and the outer edge of the cover plate 11 is greater than or equal to 0 and less than or equal to 5 mm, that is, the distance L3 between the outer edge of the connecting ring 31 and the outer edge of the cover plate 11 is greater than or equal to 0 and less than or equal to 5 mm. For example, the distance L3 between the outer edge of the connecting ring 31 and the outer edge of the cover plate 11 can be 0.3 mm, 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 1.7 mm, 2 mm, 2.3 mm, 2.5 mm, 2.8 mm, 3 mm, 3.2 mm, 3.5 mm, 3.7 mm, 4 mm, 4.3 mm, 4.5 mm, 4.8 mm, etc.

[0070] If the distance L3 between the outer edge of the connecting ring 31 and the outer edge of the cover plate 11 is too large, the radius of the first current collector 3 is smaller, that is, the area of ​​the first current collector 3 is smaller. While ensuring the area of ​​the first pole tab welding area 33a, the area of ​​the cover plate welding area 31a is smaller, which affects the flow area between the first current collector 3 and the cover plate 11; conversely, if the area of ​​the first pole tab welding area 33a is smaller while ensuring the area of ​​the cover plate welding area 31a, the flow area between the first current collector 3 and the first pole tab 21 is affected.

[0071] The above numerical range ensures that the area of ​​the cover plate welding area 31a and the area of ​​the first tab welding area 33a are sufficient, that is, the welding area requirements of the first current collector 3 and the first tab 21 and the welding area requirements of the first current collector 3 and the cover plate 11 are met, and the flow area will not be affected.

[0072] Moreover, the distance between the outer edge of the first current collecting part 3 and the outer edge of the cover plate 11 is small, that is, the distance L3 between the outer edge of the connecting ring 31 and the outer edge of the cover plate 11 is small, which can reduce the eccentricity of the connecting ring 31, thereby increasing the concentricity between the first current collecting part 3 and the cover plate 11.

[0073] In this example embodiment, the shortest distance between the cover plate welding area 31a and the outer edge of the first current collecting member 3 is greater than or equal to 0 and less than or equal to 5 mm, that is, the shortest distance between the cover plate welding area 31a and the outer edge of the connecting ring 31 is greater than or equal to 0 and less than or equal to 5 mm. For example, the shortest distance between the cover plate welding area 31a and the outer edge of the connecting ring 31 can be 0.3 mm, 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 1.7 mm, 2 mm, 2.3 mm, 2.5 mm, 2.8 mm, 3 mm, 3.2 mm, 3.5 mm, 3.7 mm, 4 mm, 4.3 mm, 4.5 mm, 4.8 mm, etc. The shortest distance between the cover plate welding area 31a and the outer edge of the connecting ring 31 refers to the shortest distance between the outer edge of the cover plate welding area 31a and the outer edge of the connecting ring 31.

[0074] If the shortest distance between the cover plate welding area 31a and the outer edge of the connecting ring 31 is too large, the area of ​​the cover plate welding area 31a is too small, and the connection strength requirements and flow area requirements between the cover plate 11 and the connecting ring 31 (first current collecting part 3) cannot be met.

[0075] The above numerical range can meet the requirements of the connection strength and flow area between the cover plate 11 and the connection ring 31 (first current collecting member 3 ).

[0076] In this example embodiment, the wall thickness of the first current collecting member 3 is greater than or equal to 0.3 mm and less than or equal to 0.4 mm. For example, the wall thickness of the first current collecting member 3 may be 0.32 mm, 0.35 mm, 0.37 mm, and so on.

[0077] If the wall thickness of the first current collector 3 is too small, especially when it is smaller than the chamfer size of the corner of the step of the jig, the first current collector 3 is easy to slide off the jig, which is not conducive to ensuring the concentricity accuracy between the cover plate 11 and the first current collector 3; if the wall thickness of the first current collector 3 is too large, it occupies too much height space in the battery casing 1, which is not conducive to improving the energy density of the cylindrical battery and is difficult to form.

[0078] It should be noted that the wall thickness of the first current collecting member 3 refers to the thickness of the connecting ring 31 , the connecting cylinder 32 and the connecting disk 33 , rather than the height of the first current collecting member 3 as a whole in the axial direction X of the cylindrical battery.

[0079] In this example implementation, refer to Figure 2As shown, the first tab welding area 33a is arranged between the battery cell 2 and the cover plate welding area 31a. Specifically, in the axial direction X of the cylindrical battery, the first tab welding area 33a is arranged between the battery cell 2 and the cover plate welding area 31a. The cylindrical battery may also include a support portion 4, which is arranged between the cover plate welding area 31a and the battery cell 2 and supports the cover plate welding area 31a. Specifically, the support portion 4 is arranged on the side of the connecting ring 31 close to the battery cell 2 and on the side of the connecting tube 32 away from the central axis. When the cylindrical battery is assembled, the support portion 4 is used to support the connecting ring 31. The side of the support portion 4 away from the connecting ring 31 can be overlapped on the step of the jig. The support portion 4 can press the connecting ring 31 and the cover plate 11 to strengthen the fit between the welding surfaces of the connecting ring 31 and the cover plate 11, thereby ensuring the welding effect of the connecting ring 31 and the cover plate 11.

[0080] The support portion 4 may be disposed against the battery cell 2 , and the battery cell 2 further supports the support portion 4 and the cover plate welding area 31 a .

[0081] In some exemplary embodiments of the present disclosure, the support portion 4 and the connecting ring 31 may be an integrally formed structure, that is, the support portion 4 and the connecting ring 31 may be prepared by an integrally formed process, so that the support portion 4 and the connecting ring 31 are an integrally connected structure. In this case, the material of the support portion 4 and the material of the connecting ring 31 may be the same, and the support portion 4 may also play a role in increasing the flow area.

[0082] In other example embodiments of the present disclosure, the support portion 4 and the connecting ring 31 may be split-molded structures, that is, the support portion 4 and the connecting ring 31 are not one-piece molded structures, and are not prepared by an one-piece molding process; the material of the support portion 4 may be a conductor, and the support portion 4 may also serve to increase the flow area.

[0083] In some other example embodiments of the present disclosure, the support portion 4 and the connecting ring 31 may be split-molded structures, that is, the support portion 4 and the connecting ring 31 are not one-piece molded structures, and are not prepared by an one-piece molding process; the material of the support portion 4 may be an insulating material, that is, the support portion 4 may be a part of the insulating part.

[0084] In this exemplary embodiment, the support portion 4 may be provided in a ring shape, specifically, the support portion 4 may be provided in a circular ring shape, so that each position of the connection ring 31 can be supported by the support portion 4 .

[0085] In some other exemplary embodiments of the present disclosure, the support portion 4 may include a plurality of protrusions disposed at intervals, and the plurality of protrusions surround to form at least one circle, that is, the plurality of protrusions surround to form one, two or more circles of annular shape.

[0086] In this example implementation, refer to Figure 2As shown, in the radial direction Y of the cylindrical battery, the distance between the side of the support portion 4 close to the connecting cylinder 32 and the side of the connecting cylinder 32 close to the support portion 4 is L1, and the distance between the side of the support portion 4 away from the connecting cylinder 32 and the outer annular surface of the first current collecting member 3 is L2, and L1 is smaller than L2; that is, the support portion 4 is arranged closer to the connecting cylinder 32, so that the support portion 4 can reinforce the connecting cylinder 32 and prevent the connecting cylinder 32 from deformation.

[0087] It should be noted that the radial direction Y of the cylindrical battery is a plurality of directions perpendicular to the axial direction X of the cylindrical battery, and only one direction is schematically indicated in the figure.

[0088] In this example embodiment, in the axial direction X of the cylindrical battery, the thickness of the support portion 4 is greater than or equal to 1.3 mm and less than or equal to 1.9 mm. For example, the thickness of the support portion 4 can be 1.32 mm, 1.35 mm, 1.37 mm, 1.4 mm, 1.43 mm, 1.45 mm, 1.48 mm, 1.5 mm, 1.52 mm, 1.55 mm, 1.57 mm, 1.6 mm, 1.63 mm, 1.65 mm, 1.68 mm, 1.7 mm, 1.72 mm, 1.75 mm, 1.77 mm, 1.8 mm, 1.83 mm, 1.85 mm, 1.88 mm, and the like.

[0089] If the thickness of the support portion 4 is too large, when the support portion 4 is a conductor, the side of the support portion 4 close to the battery cell 2 is too close to the battery cell 2, and the side of the support portion 4 close to the battery cell 2 is also too close to the second current collector 5, which is not conducive to the insulation between the first current collector 3 and the second current collector 5; when the support portion 4 is made of insulating material, the support portion 4 occupies more axial space of the battery casing 1, which is not conducive to improving the space utilization of the battery casing 1 and the energy density of the cylindrical battery.

[0090] If the thickness of the support portion 4 is too small, the strength of the support portion 4 is too small, and the support portion 4 cannot play a role in reinforcing the connecting tube 32 ; nor can the support portion 4 play a role in supporting the connecting ring 31 .

[0091] The above numerical range, when the support part 4 is a conductor, not only ensures the insulation effect between the first current collecting part 3 and the second current collecting part 5; when the support part 4 is an insulating material, it ensures the space utilization of the battery housing 1 and the energy density of the cylindrical battery; and also ensures that it can play a role in reinforcing the connecting tube 32 and supporting the connecting ring 31.

[0092] In this example implementation, refer to Figure 2As shown, the cylindrical battery may further include a second current collector 5, the second current collector 5 having a polarity opposite to that of the first current collector 3. For example, the first current collector 3 may be a negative electrode current collector, and the second current collector 5 may be a positive electrode current collector. Of course, the first current collector 3 may also be a positive electrode current collector, and the second current collector 5 may be a negative electrode current collector.

[0093] Reference Figure 4 As shown, the second current collector 5 has a second pole tab welding area 52a, and a part of the second current collector 5 may be the second pole tab welding area 52a, or the entire second current collector 5 may be the second pole tab welding area 52a. The second pole tab welding area 52a is connected to the second pole tab 22, specifically, the second pole tab welding area 52a is welded to the second pole tab 22, so that a welding portion is provided between the second pole tab welding area 52a and the second pole tab 22.

[0094] The second current collecting part 5 may include a first current collecting part 51 and a second current collecting part 52, wherein the first current collecting part 51 is connected to the second current collecting part 52. The first current collecting part 51 is configured as a semicircular ring structure, that is, the first current collecting part 51 is configured as a fan ring structure, and the second current collecting part 52 is configured as a circular structure, and the second current collecting part 52 is connected to the inner annular surface of the first current collecting part 51 with a smaller radius.

[0095] Moreover, the second current collecting part 5 needs to be connected to the battery pole. Specifically, the second current collecting part 52 is welded to the battery pole. Therefore, a protruding structure is provided on the second current collecting part 52. The protruding structure is provided in a cylindrical shape to cooperate with the cylindrical recessed structure on the battery pole.

[0096] The first pole tab 21 may include multiple first pole tab layers, and the second pole tab 22 may include multiple second pole tab layers; and the number of first pole tab layers included in the first pole tab 21 is substantially the same as the number of second pole tab layers included in the second pole tab 22. The first pole tab layer may be an aluminum foil, and the second pole tab layer may be a copper foil. The thickness of the aluminum foil is different from that of the copper foil, resulting in a large difference in the thickness of the first pole tab 21 formed by stacking multiple first pole tab layers and the thickness of the second pole tab 22 formed by stacking multiple second pole tab layers.

[0097] The welding surface of the first current collector 3 and the first pole tab 21 needs to fit tightly, and the welding surface of the second current collector 5 and the second pole tab 22 also needs to fit tightly. If the pole tabs of different thicknesses are matched with the current collectors of the same horizontal plane, when the current collectors are pressed, the current collector with the thicker pole tab must bear greater pressure to ensure the tight fit of the current collector with the thinner pole tab, which is not conducive to the consistency of the force applied to the battery cell 2 and is difficult to control the pressure.

[0098] Therefore, refer to Figure 2As shown, the second current collector 5 is also disposed between the cover plate 11 and the battery cell 2, and the side of the second pole tab welding area 52a close to the second pole tab 22 and the side of the first pole tab welding area 33a close to the first pole tab 21 are located in different planes. This allows the welding surface of the first current collector 3 and the first pole tab 21 to be closely fitted, while the welding surface of the second current collector 5 and the second pole tab 22 can also be closely fitted; and the forces on the first current collector 3 and the second current collector 5 are also substantially the same.

[0099] Specifically, if the single-piece thickness of the second pole ear 22 is smaller than the single-piece thickness of the first pole ear 21, the thickness of the second pole ear 22 is smaller than the thickness of the first pole ear 21, that is, the side of the second pole ear 22 facing away from the battery cell 2 is closer to the battery cell 2 than the side of the first pole ear 21 facing away from the battery cell 2. Therefore, the second current collector 5 is closer to the battery cell 2 than the first current collector 3, specifically, the side of the second pole ear welding area 52a close to the second pole ear 22 is closer to the battery cell 2 than the side of the first pole ear welding area 33a close to the first pole ear 21, so that the welding surface of the first current collector 3 and the first pole ear 21 can be tightly fitted, and the welding surface of the second current collector 5 and the second pole ear 22 can also be tightly fitted.

[0100] On the contrary, if the single-piece thickness of the second pole ear 22 is greater than the single-piece thickness of the first pole ear 21, the thickness of the second pole ear 22 is greater than the thickness of the first pole ear 21, that is, the side of the second pole ear 22 facing away from the battery cell 2 is farther away from the battery cell 2 than the side of the first pole ear 21 facing away from the battery cell 2. Therefore, the first current collector 3 is closer to the battery cell 2 than the second current collector 5, specifically, the side of the first pole ear welding area 33a close to the first pole ear 21 is closer to the battery cell 2 than the side of the second pole ear welding area 52a close to the second pole ear 22. This can also make the welding surfaces of the first current collector 3 and the first pole ear 21 welded to each other tightly fitted, and the welding surfaces of the second current collector 5 and the second pole ear 22 welded to each other tightly fitted.

[0101] Reference Figure 2 As shown, the height difference between the side of the second pole tab welding area 52a close to the second pole tab 22 and the side of the first pole tab welding area 33a close to the first pole tab 21 is H1, and the height difference between the side of the second pole tab 22 close to the second pole tab welding area 52a and the side of the first pole tab 21 close to the first pole tab welding area 33a is H2, and H1 is equal to H2, that is, H1 and H2 are basically the same.

[0102] Specifically, the height difference between the second current collecting member 5 and the first current collecting member 3 is greater than or equal to 0.15 mm and less than or equal to 0.2 mm. For example, the height difference between the second current collecting member 5 and the first current collecting member 3 may be 0.16 mm, 0.17 mm, 0.18 mm, 0.19 mm, etc.

[0103] It should be noted that H1 equals H2, which not only includes that H1 and H2 are completely identical, but also that there may be a certain error between them. The error range varies depending on the equipment and the preparation process. Therefore, within the error range of the equipment and the preparation process, they are considered to be the same.

[0104] The "parallel" and "perpendicular" mentioned in this application can not only be completely parallel or perpendicular, but also can have a certain error; for example, if the angle between the two is greater than or equal to 0° and less than or equal to 5°, the two are considered to be parallel to each other; if the angle between the two is greater than or equal to 85° and less than or equal to 95°, the two are considered to be perpendicular to each other.

[0105] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the utility model disclosed herein. This application is intended to cover any variations, uses or adaptations of the present disclosure, which follow the general principles of the present disclosure and include common knowledge or customary technical means in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.

Claims

1. A cylindrical battery, characterized in that: include: Battery housing, including cover; A battery cell is disposed in the battery housing, and the battery cell includes a first pole tab; A first current collector is provided between the cover plate and the battery cell, the first current collector having a cover plate welding area and a first pole tab welding area, the cover plate welding area is connected to the cover plate, and the first pole tab welding area is connected to the first pole tab; Wherein, the ratio of the radius of the cover plate to the radius of the first current collecting member is greater than or equal to 1 and less than or equal to 1.

5.

2. The cylindrical battery according to claim 1, characterized in that: The first tab welding area is connected to a side of the cover plate welding area close to the central axis of the cylindrical battery.

3. The cylindrical battery according to claim 2, characterized in that: A distance between an outer edge of the first current collecting member and an outer edge of the cover plate is greater than or equal to 0 and less than or equal to 5 mm.

4. The cylindrical battery according to claim 2, characterized in that: The shortest distance between the cover plate welding area and the outer edge of the first current collecting member is greater than or equal to 0 and less than or equal to 5 mm.

5. The cylindrical battery according to claim 2, characterized in that: The first current collecting member comprises: A connecting ring, which is arranged in a circular ring shape, and the connecting ring includes the cover plate welding area; A connecting tube connected to a side of the connecting ring close to the battery core; A connecting disk is connected to a side of the connecting tube close to the battery core. The connecting disk is arranged in a fan ring shape and includes the first pole ear welding area. The connecting ring, the connecting tube and the connecting disk are arranged coaxially.

6. The cylindrical battery according to claim 5, characterized in that: The ratio of the ring width of the connecting ring to the radius of the cover plate is greater than or equal to 0.01 and less than or equal to 0.

5.

7. The cylindrical battery according to claim 6, characterized in that: The ring width of the connecting ring is greater than or equal to 0.5 mm and less than or equal to 5 mm.

8. The cylindrical battery according to claim 5, characterized in that: The connecting ring and the connecting tube are transitionally connected via an arc portion, and the central angle of the arc portion is greater than or equal to 30° and less than or equal to 170°.

9. The cylindrical battery according to claim 5, characterized in that: The first tab welding area is disposed between the battery cell and the cover plate welding area, and the cylindrical battery further includes: The support portion is disposed between the cover plate welding area and the battery core and supports the cover plate welding area.

10. The cylindrical battery according to claim 9, characterized in that: The supporting portion is disposed in contact with the battery core.

11. The cylindrical battery according to claim 9, characterized in that: The support portion and the connecting ring are an integrally formed structure; or, the support portion and the connecting ring are a split-formed structure, and the support portion is a conductor; or, the support portion and the connecting ring are a split-formed structure, and the support portion is an insulating member.

12. The cylindrical battery according to claim 9, characterized in that: The support portion is arranged in a ring shape, or the support portion includes a plurality of protrusions arranged at intervals, and the plurality of protrusions surround to form at least one circle.

13. The cylindrical battery according to claim 9, characterized in that: In the radial direction of the cylindrical battery, the distance between the side of the support portion close to the connecting tube and the side of the connecting tube close to the support portion is L1, and the distance between the side of the support portion away from the connecting tube and the outer annular surface of the first current collecting member is L2, and L1 is smaller than L2.

14. The cylindrical battery according to claim 9, characterized in that: In the axial direction of the cylindrical battery, the thickness of the support portion is greater than or equal to 1.3 mm and less than or equal to 1.9 mm.

15. The cylindrical battery according to claim 1, characterized in that: The wall thickness of the first current collecting member is greater than or equal to 0.3 mm and less than or equal to 0.4 mm.

16. The cylindrical battery according to any one of claims 1 to 15, characterized in that: The battery cell includes a second pole ear, and the second pole ear and the first pole ear are located on the same end surface of the battery cell; the cylindrical battery further includes: A second current collector has a polarity opposite to that of the first current collector, and is disposed between the cover plate and the battery cell; the second current collector has a second pole tab welding area, the second pole tab welding area is connected to the second pole tab, and a surface of the second pole tab welding area close to the second pole tab and a surface of the first pole tab welding area close to the first pole tab are located in different planes.

17. The cylindrical battery according to claim 16, characterized in that: If the thickness of the second electrode tab is smaller than the thickness of the first electrode tab, the second current collector is closer to the battery cell than the first current collector; If the thickness of the second electrode tab is greater than the thickness of the first electrode tab, the first current collecting member is closer to the battery cell than the second current collecting member.

18. The cylindrical battery according to claim 16, characterized in that: A height difference between a side of the second pole tab welding area close to the second pole tab and a side of the first pole tab welding area close to the first pole tab is H1, and a height difference between a side of the second pole tab close to the second pole tab welding area and a side of the first pole tab close to the first pole tab welding area is H2, and H1 is equal to H2.

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