Cylindrical battery and battery pack

Abstract

Cylindrical battery comprising the following: a battery cell (2) comprising a first electrode tab (21) and a second electrode tab (22) extending from the same end along an axial direction, wherein the first electrode tab (21) and the second electrode tab (22) have opposite polarities; a cover plate arrangement (3) comprising a cover plate body (33) and a connection (32) which is arranged to penetrate the cover plate body (33); a current collector arrangement (4) connected between the battery cell (2) and the cover plate arrangement (3); wherein the current collector arrangement (4) comprises a first current collector (41) electrically connected to the first electrode tab (21) and a second current collector (42) electrically connected to the second electrode tab (22); wherein the first current collector (41) is electrically connected to the terminal (32), the terminal (32) being located in an inner region of a housing and the second current collector (42) being located on the same end face of the battery cell (2); along the axial direction, a projection on one side of the terminal (32) close to the battery cell (2) at least partially overlaps the second current collector (42) to form an overlapping region; an insulating layer (31) which is arranged at least partially between the second current collector (42) and the terminal (32), wherein a projection of the insulating layer (31) on a plane perpendicular to the axial direction covers the overlapping area; wherein a width d1 of the insulating layer (31) along a radial direction and a width d2 of the overlapping area along the radial direction satisfy the following: 1,1 ≤ d1 / d2 ≤ 5 .

Description

Technical field

[0001] The present application relates to the field of battery technology or accumulator technology, specifically a cylindrical battery and a battery pack. background

[0002] A cylindrical battery contains a battery cell and a cover plate, with electrode tabs extending from the battery cell and a terminal or pole located on the cover plate. In related technologies, current collectors are used to create an intermediate connection between the electrode tabs and the terminal.

[0003] The current collectors and the terminal are both attached to the cover plate. Due to the large surface area of ​​the terminal, after assembly there is a possibility of contact between the terminal and a current collector with the opposite polarity, causing a short circuit in the battery. Summary

[0004] In view of this, the present application provides a cylindrical battery and a battery pack to solve the problem of battery short circuits caused by slight contact between the terminal and a current collector with opposite polarity.

[0005] According to a first aspect, the present application provides a cylindrical battery comprising the following: a battery cell comprising a first electrode tab and a second electrode tab extending from the same end along an axial direction, wherein the first electrode tab and the second electrode tab have opposite polarities; a cover plate arrangement comprising a cover plate body and a connection arranged to penetrate the cover plate body; a current collector arrangement connected between the battery cell and the cover plate arrangement; wherein the current collector arrangement comprises a first current collector electrically connected to the first electrode tab and a second current collector electrically connected to the second electrode tab; wherein the first current collector is electrically connected to the terminal, the terminal being located in an inner region of a housing and the second current collector being located on the same end face of the battery cell; along the axial direction, a projection on one side of the terminal close to the battery cell at least partially overlaps the second current collector to form an overlapping region; an insulating layer which is at least partially arranged between the second current collector and the terminal, wherein a projection of the insulating layer on a plane perpendicular to the axial direction covers the overlapping area; where a width d1 of the insulating layer along a radial direction and a width d2 of the overlapping area along the radial direction satisfy the following: 1.1 ≤ d1 / d2 ≤ 5.

[0006] Advantageous effects: By placing an insulating layer between the second current collector and the terminal, and by creating a projection of the insulating layer along the axial direction to cover the overlapping area, the insulating effect between the second current collector and the terminal is ensured, thus preventing a short circuit caused by contact between the terminal and the current collector with opposite polarity. The width of the insulating layer along the radial direction must be sufficient to cover the overlapping area.If the width of the insulating layer along the radial direction is too small, the overlapping area is exposed, and there remains a risk of contact between the terminal and the current collector with opposite polarity; if the width of the insulating layer along the radial direction is too large, this can affect the heat dissipation of the cover plate assembly and the current collector assembly.

[0007] According to a second aspect, the present application also provides a battery pack comprising the cylindrical battery.

[0008] Because the battery pack includes the cylindrical battery, it has the same effects as the cylindrical battery, which are not repeated here. Brief description of the drawings

[0009] To more clearly illustrate the technical solutions according to the specific embodiments or the prior art of the present application, a brief introduction is given to the drawings that must be used when describing the specific embodiments or the prior art. Obviously, the drawings described below represent some embodiments of the present application. Those skilled in the field can derive other drawings from these without any creative effort. Fig. Figure 1 is a schematic view of the cylindrical battery of the present application; Fig. Figure 2 is an exploded view of the cylindrical battery of the present application; Fig. Figure 3 is a schematic view of the current collector arrangement in an exploded state with the cover plate arrangement of the present application; Fig. Figure 4 is a schematic view of the cover plate arrangement in an exploded state with the current collector arrangement of the present application; Fig. Figure 5 is a schematic view showing the arrangement of the terminal, the insulating layer and the current collector arrangement of the present application; Fig. Figure 6 is a front view of the current collector arrangement and the cover plate arrangement of the present application; Fig. Figure 7 is a schematic view showing the arrangement of the current collector assembly and the connection in the AA section state. Fig. 6 of the present application shows; Fig. Figure 8 is an exploded view of the insulating layer, the current collector arrangement and the connection in AA section. Fig. 6 of the present application; Reference symbol:

[0010] 1, Housing; 2, Battery cell; 21, First electrode tab; 22, Second electrode tab; 3, Cover plate assembly; 31, Insulating layer; 32, Terminal; 321, Flange section; 33, Cover plate body; 4, Current collector assembly; 41, First current collector; 42, Second current collector; 43, Assembly component; 44, Projection. Detailed description

[0011] To clarify the purpose, technical solutions, and advantages of the embodiments of the present application, the technical solutions according to the embodiments of the present application are described clearly and completely in conjunction with the drawings according to the embodiments of the present application. Obviously, the described embodiments are some, but not all, embodiments of the present application. All other embodiments that could be obtained by those skilled in the art based on the embodiments of the present application without any creative effort are intended to fall within the scope of protection of the present application.

[0012] The description of this application should state that terms such as "middle", "top", "bottom", "left", "right", "vertical", "horizontal", "inside", "outside", which indicate an orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings and serve only for the convenience of description and simplification of this application, rather than indicating or implying that the designated device or element must have a specific orientation, be erected in a specific orientation, or be operated in a specific orientation. Therefore, they should not be understood as limitations of this application. Furthermore, the terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying any relative importance.

[0013] The description of this application should state that the terms "installed", "connected", and "coupled" should be understood broadly unless explicitly specified and limited elsewhere. They may, for example, mean a fixed connection, a detachable connection, or a one-piece connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection via intermediate media; or internal communication between two elements. Those skilled in the field will be able to understand the specific meanings of these terms in this application according to the specific situations.

[0014] Furthermore, the technical features included in the various embodiments of the present application can be combined with each other, as long as they do not conflict with each other.

[0015] The embodiments of the present application are described in connection with the Fig. 1 to 8 described.

[0016] According to one embodiment of the present application, a cylindrical battery is provided, comprising the following: a battery cell 2 comprising a first electrode tab 21 and a second electrode tab 22 extending from the same end along an axial direction, wherein the first electrode tab 21 and the second electrode tab 22 have opposite polarities; a cover plate arrangement 3 comprising a cover plate body 33 and a connection 32 which is arranged to penetrate the cover plate body 33; a current collector arrangement 4 connected between the battery cell 2 and the cover plate arrangement 3; wherein the current collector arrangement 4 comprises a first current collector 41 electrically connected to the first electrode tab 21 and a second current collector 42 electrically connected to the second electrode tab 22; wherein the first current collector 41 is electrically connected to the terminal 32, the terminal 32 being located in an inner region of a housing and the second current collector 42 being located on the same end face of the battery cell 2; along the axial direction, a projection on one side of the terminal 32 close to the battery cell 2 at least partially overlaps the second current collector 42 to form an overlapping region; an insulating layer 31 which is arranged at least partially between the second current collector 42 and the terminal 32, wherein a projection of the insulating layer 31 on a plane perpendicular to the axial direction covers the overlapping area; where a width d1 of the insulating layer 31 along a radial direction and a width d2 of the overlapping area along the radial direction satisfy the following: 1.1 ≤ d1 / d2 ≤ 5.

[0017] It should be mentioned that, because the cylindrical battery is constructed in a cylindrical shape, the axial direction of battery cell 2 refers to the direction parallel to the central axis of the cylinder. Specifically, according to this embodiment, the axial direction of battery cell 2 refers to the direction in Fig. 2. Arrow direction shown.

[0018] Due to the limited area of ​​the cylindrical battery's end face, there is a competing relationship in the radial direction between terminal 32 and the opposite-polarity current collector, both of which exit from the same end. This easily leads to contact between terminal 32 and the opposite-polarity current collector, causing short-circuit problems. With prismatic batteries, there is no risk of opposite-polarity contact causing a short circuit because their terminals are arranged with a large distance between them at both ends.

[0019] The cylindrical battery of this embodiment comprises a cylindrical housing 1, wherein at least one end forms an opening along the axial direction, the cover plate arrangement 3, which covers the opening of the housing 1, a hollow cavity formed by a sealed connection and a common enclosure of the housing 1 and the cover plate arrangement 3, and the battery cell 2, which is arranged in the hollow cavity.

[0020] Because both the first electrode tab 21 and the second electrode tab 22 extend from the same end of the battery cell 2 along the axial direction, the first electrode tab 21 and the second electrode tab 22 are spaced apart along the axial direction around the end face of the battery cell 2. According to this embodiment, both the first electrode tab 21 and the second electrode tab 22 are arranged in a sector shape.

[0021] The cover plate arrangement 3 is provided with a connection 32, wherein according to this embodiment the connection 32 is designed as a cylindrical shape or as a body of revolution about the central axis, wherein the cover plate arrangement 3 comprises a cover plate body 33, wherein the connection 32 is arranged to penetrate the cover plate body 33.

[0022] To facilitate the electrical connection between the battery cell 2 and the cover plate arrangement 3, a current collector arrangement 4 is arranged between them to establish an intermediate connection.

[0023] The current collector arrangement 4 comprises a first current collector 41, which is electrically connected to the first electrode tab 21, and a second current collector 42, which is electrically connected to the second electrode tab 22; wherein one of the first current collector 41 and the second current collector 42 is electrically connected to the terminal 32, while the projection of the other, along the axial direction, at least partially overlaps one side of the terminal 32 near the battery cell 2, forming an overlapping region. Taking the first current collector 41, which is electrically connected to the terminal 32, as an example, the projection of the second current collector 42, along the axial direction, at least partially overlaps the side of the terminal 32 near the battery cell 2, because the second current collector 42 must conform to the shape of the second electrode tab 22 and the interior of the cylindrical battery is compact.If there were no overlapping area between the projection of the second current collector 42 along the axial direction and the side of the terminal 32 near the battery cell 2, this would easily lead to an oversized cylindrical battery or a second electrode tab 22 that is too small, which is unfavorable for current transmission.

[0024] As in Fig. As shown in Figure 3, the current collector arrangement 4 further comprises an arrangement component 43, wherein the first current collector 41 and the second current collector 42 are jointly attached to the arrangement component 43 to form a one-piece current collector arrangement 4.

[0025] According to one implementation, the first current collector 41 can be a positive current collector, while the second current collector 42 can be a negative current collector. According to another implementation, the first current collector 41 can be a negative current collector, while the second current collector 42 can be a positive current collector.

[0026] If the projection of the second current collector 42, along the axial direction, at least partially overlaps the side of the terminal 32 near the battery cell 2 and forms an overlapping area, a short circuit can occur due to contact between the terminal 32 and the current collector with opposite polarity, because the second current collector 42 and the terminal 32 have opposite polarities. Conversely, if the second current collector 42 is electrically connected to the terminal 32, similar situations arise, which will not be repeated here. The following description continues, taking the first current collector 41, which is electrically connected to the terminal 32, as an example.

[0027] According to this embodiment, by arranging an insulating layer 31 between the second current collector 42 and the terminal 32, and by creating a projection of the insulating layer 31 on a plane perpendicular to the axial direction so that it covers the overlapping area, the insulating effect between the second current collector 42 and the terminal 32 is ensured, thereby preventing a short circuit caused by contact between the terminal 32 and the current collector with opposite polarity. The width of the insulating layer 31 along the radial direction must be sufficient to cover the overlapping area.If the width of the insulating layer 31 along the radial direction is too small, the overlapping area is exposed, and there remains a risk of contact between the terminal 32 and the current collector with opposite polarity; if the width of the insulating layer 31 along the radial direction is too large, it can affect the heat dissipation of the cover plate arrangement 3 and current collector arrangement 4.

[0028] This embodiment ensures sufficient coverage of the overlapping area by the insulating layer 31 along the radial direction by limiting the lower limit of the ratio between the width d1 of the insulating layer 31 along the radial direction and the width d2 of the overlapping area along the radial direction, thereby preventing the overlapping area from being exposed due to an insufficient width of the insulating layer 31 and consequently reducing the risk of contact between the terminal 32 and the current collector with opposite polarity; and prevents the insulating layer 31 from being too wide, which would affect the heat dissipation of the cover plate arrangement 3 and the current collector arrangement 4, by limiting the upper limit of the ratio between the width d1 of the insulating layer 31 along the radial direction and the width d2 of the overlapping area along the radial direction.

[0029] According to some embodiments, the insulating layer 31 is arranged on a side of the cover plate body 33 that faces the current collector arrangement 4, at least partially surrounding the terminal 32.

[0030] According to this embodiment, the insulating layer 31 surrounds the terminal 32 at least partially, which allows the insulating layer 31 to cover at least the overlapping area between the terminal 32 and the current collector with opposite polarity, wherein by arranging the insulating layer 31 on the side of the cover plate body 33 facing the current collector arrangement 4, the insulating effect between the terminal 32 and the current collector with opposite polarity is ensured, thereby avoiding a short circuit caused by the contact between the terminal 32 and the current collector with opposite polarity.

[0031] According to some embodiments, the insulating layer 31 is arranged surrounding the terminal 32.

[0032] According to this embodiment, the insulating layer 31 is constructed in a ring shape with a hollow design in the center, which allows the insulating layer 31 to surround the terminal 32. This ensures better insulation between the terminal 32 and the opposite-polarity current collector, thus preventing a short circuit caused by contact between the terminal 32 and the opposite-polarity current collector. Meanwhile, space is provided for the connection between a projection 44 and the terminal 32, preventing interference and poor contact between the projection 44 and the terminal 32.

[0033] According to some embodiments, the insulating layer 31 is arranged discontinuously around the terminal 32.

[0034] According to this embodiment, by arranging the insulating layer 31 on the side of the cover plate body 33 facing the current collector arrangement 4, it can at least cover the overlapping area between the terminal 32 and the current collector with opposite polarity, thus ensuring the insulating effect between them and preventing a short circuit caused by the contact. The discontinuous arrangement of the insulating layer 31 around the terminal 32 leaves gaps between the insulating layers, which provides better heat dissipation.

[0035] According to some embodiments, the width d1 of the insulating layer 31 along the radial direction satisfies: 1 mm ≤ d1 ≤ 15 mm.

[0036] By limiting the lower boundary of the width d1 of the insulating layer 31 along the radial direction, sufficient coverage of the overlapping area is ensured, thus preventing the overlapping area from being exposed and avoiding the risk of contact between the terminal 32 and the current collector with opposite polarity. Limiting the upper boundary of the width d1 prevents the width from being too large, which would impair the heat dissipation of the cover plate arrangement 3 and the current collector arrangement 4, thereby ensuring effective heat dissipation.

[0037] According to this embodiment, the specific value of the width d1 of the insulating layer 31 along the radial direction can be 1 mm, 2 mm, 4 mm, 5 mm, 7 mm, 8 mm, 10 mm, 13 mm, 14 mm or 15 mm, etc.

[0038] According to some embodiments, a vertical distance d4 between one side of the terminal 32 near the battery cell 2 and the second current collector 42 and a thickness d3 of the insulating layer 31 fulfill the following: 0 mm 2 ≤ d3 · d4 ≤ 3 mm 2 .

[0039] Because the insulating layer 31 must ensure the insulation between the terminal 32 and the current collector with opposite polarity, the vertical distance d4 between the terminal 32 and the second current collector 42 can be appropriately larger, thereby reducing the risk of an electrical connection between the terminal 32 and the second current collector 42, in which case the thickness of the insulating layer 31 can be relatively smaller.

[0040] If the vertical distance d4 between the terminal 32 and the second current collector 42 is relatively small, the risk of an electrical connection between the terminal 32 and the second current collector 42 is higher, in which case the thickness of the insulating layer 31 must be increased to ensure the insulating effect and to reduce the risk of contact between the terminal 32 and the current collector with opposite polarity.

[0041] According to some embodiments, the side of the terminal 32 near the battery cell 2 is bent / folded outwards along the radial direction to form a flange section 321, as shown in Fig. 8 is shown.

[0042] The cover plate body 33 is provided with a through-hole for connection. During assembly, the connection 32 passes through the through-hole and is bent / folded to form the flange section 321, thereby securing the connection 32 to both sides of the cover plate body 33.

[0043] On the side of the terminal 32 facing the battery cell 2, a groove is formed in the inside of the area enclosed by the flange section 321 along the radial direction. Accordingly, the first current collector 41 extends towards the terminal 32 to form a projection 44 that extends into the groove and is secured by welding, thereby establishing a fixed connection between the first current collector 41 and the terminal 32.

[0044] According to this embodiment, the insulating layer 31 is appropriately attached to the flange section 321.

[0045] According to some embodiments, one of the first current collector 41 and the second current collector 42 extends towards the terminal 32 to form the projection 44 which is electrically connected to the terminal 32, as shown in Fig. 8 is shown.

[0046] According to some embodiments, the projection of the insulating layer 31 does not overlap the projection 44 along the axial direction.

[0047] The first current collector 41 extends towards the terminal 32 to form the projection 44, which extends into the groove and is secured by welding, thereby establishing a firm connection between the first current collector 41 and the terminal 32. According to this embodiment, by ensuring that the projection of the insulating layer 31 does not overlap the projection 44 along the axial direction, the insulating layer 31 is prevented from interfering with the insertion of the projection into the terminal groove, thus avoiding poor contact between the projection 44 and the inner walls of the groove.

[0048] To ensure the welding effect, the projection 44 must be in close contact with the bottom wall of the groove.

[0049] According to some embodiments, the thickness d3 of the insulating layer 31 satisfies: 0.02 mm ≤ d3 ≤ 0.5 mm.

[0050] If the thickness d3 of the insulating layer 31 is too thin, there is a risk of insulation failure, whereas if the thickness d3 of the insulating layer 31 is too thick, the welding distance between the projection 44 and the groove bottom wall is increased, preventing complete contact between the projection 44 and the groove bottom wall, which can lead to poor welding and affect the electrical connection between the first current collector 41 and the terminal 32.

[0051] According to another aspect of the embodiments of the present application, a battery pack is also provided which includes the cylindrical battery described above.

[0052] Obviously, the embodiments described above are merely examples for clear illustration and do not represent limitations on implementation. Although the embodiments of the present application have been described in conjunction with the drawings, those skilled in the field may make various modifications and variations without deviating from the inventive concept and scope of protection of the present application, such modifications and variations falling within the scope of protection defined by the present application.

Claims

[1] Cylindrical battery comprising the following: a battery cell (2) comprising a first electrode tab (21) and a second electrode tab (22) extending from the same end along an axial direction, wherein the first electrode tab (21) and the second electrode tab (22) have opposite polarities; a cover plate arrangement (3) comprising a cover plate body (33) and a connection (32) which is arranged to penetrate the cover plate body (33); a current collector arrangement (4) connected between the battery cell (2) and the cover plate arrangement (3); wherein the current collector arrangement (4) comprises a first current collector (41) electrically connected to the first electrode tab (21) and a second current collector (42) electrically connected to the second electrode tab (22); wherein the first current collector (41) is electrically connected to the terminal (32), the terminal (32) being located in an inner region of a housing and the second current collector (42) being located on the same end face of the battery cell (2); along the axial direction, a projection on one side of the terminal (32) close to the battery cell (2) at least partially overlaps the second current collector (42) to form an overlapping region; an insulating layer (31) which is arranged at least partially between the second current collector (42) and the terminal (32), wherein a projection of the insulating layer (31) on a plane perpendicular to the axial direction covers the overlapping area; wherein a width d1 of the insulating layer (31) along a radial direction and a width d2 of the overlapping area along the radial direction satisfy the following: 1,1≤d1 / d2≤5. [2] Cylindrical battery according to claim 1, wherein the insulating layer (31) is arranged on a side of the cover plate body (33) facing the current collector arrangement (4) and at least partially surrounds the terminal (32). [3] Cylindrical battery according to claim 2, wherein the insulating layer (31) is arranged surrounding the terminal (32). [4] Cylindrical battery according to claim 2 or 3, wherein the insulating layer (31) is arranged discontinuously around the terminal (32). [5] Cylindrical battery according to any of the preceding claims, wherein the width d1 of the insulating layer (31) along the radial direction satisfies the following: 1 mm≤d1≤15 mm. [6] Cylindrical battery according to one of the preceding claims, wherein a vertical distance d4 between one side of the terminal (32) near the battery cell (2) and the second current collector (42) and a thickness d3 of the insulating layer (31) satisfy the following: 0 mm2≤d3⋅d4≤3 mm2. [7] Cylindrical battery according to one of the preceding claims, wherein the first current collector (41) extends towards the terminal (32) to form a projection (44) and the projection (44) is electrically connected to the terminal (32). [8] Cylindrical battery according to claim 7, wherein along the axial direction a projection of the insulating layer (31) does not overlap the projection (44). [9] Cylindrical battery according to claim 8, wherein the thickness d3 of the insulating layer (31) satisfies the following: 0.02 mm≤d3≤0.5 mm. [10] Cylindrical battery according to any one of claims 7 to 9, wherein the projection (44) is attached to the terminal (32) by welding. [11] Cylindrical battery according to any one of the preceding claims, wherein the side of the connection (32) near the battery cell (2) is bent outwards along the radial direction to form a flange section (321), the insulating layer (31) is attached to the flange section (321). [12] Battery pack comprising the cylindrical battery according to any one of claims 1 to 11.

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