Cylindrical batteries and battery packs

Abstract

The present invention relates to the field of battery technology, and discloses a cylindrical battery and a battery pack, wherein the cylindrical battery comprises: a battery cell; a cover plate assembly; a current collecting assembly connected between the battery cell and the cover plate assembly; a first current collecting piece electrically connected to a pole, and the area of ​​the pole inside a shell and a second current collecting piece are arranged on the same end face of the battery cell; along the axial direction, the projection of the pole close to the battery cell on the second current collecting piece at least partially overlaps with the second current collecting piece to form an overlapping area; an insulating layer, at least partially arranged between the second current collecting piece and the pole, and the projection of the insulating layer on a plane perpendicular to the axial direction covers the overlapping area; the width of the insulating layer along the radial direction is d1, and the width of the overlapping area along the radial direction is d2, and the value range of d1 / d2 satisfies: 1.1≤d1 / d2≤5. The cylindrical battery provided by the present invention ensures the insulating effect of the second current collecting piece and the pole, and avoids the situation where the pole and the opposite current collecting piece contact and short circuit occurs.

Description

Technical Field

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

[0002] The cylindrical battery includes a battery cell and a cover plate. The battery cell has a pole lug, and the cover plate is provided with a pole post. In order to achieve the connection between the pole lug and the pole post, a current collector is provided in the related art to achieve a transit connection.

[0003] The current collector and the pole are both assembled on the cover plate. Since the pole has a large area, after assembly, there is a possibility that the pole may come into contact with the current collector with opposite charges, thereby causing a short circuit in the battery. Summary of the invention

[0004] In view of this, the present invention provides a cylindrical battery and a battery pack to solve the problem that the pole and the current collector with opposite charges are easily in contact and cause a battery short circuit.

[0005] In a first aspect, the present invention provides a cylindrical battery, comprising:

[0006] The battery cell comprises a first pole ear and a second pole ear extending from the same end along the axis direction, and the first pole ear and the second pole ear have opposite polarities;

[0007] The cover plate assembly comprises a cover plate body and a pole arranged through the cover plate body;

[0008] A current collecting assembly is connected between the battery cell and the cover plate assembly; the current collecting assembly includes a first current collecting piece electrically connected to the first pole tab, and a second current collecting piece electrically connected to the second pole tab; the first current collecting piece is electrically connected to the pole, and the area of ​​the pole inside the shell and the second current collecting piece are arranged on the same end surface of the battery cell; along the axial direction, the projection of the side of the pole close to the battery cell on the second current collecting piece at least partially overlaps with the second current collecting piece to form an overlapping area;

[0009] An insulating layer, at least partially disposed between the second current collector and the pole, wherein a projection of the insulating layer on a plane perpendicular to the axis direction covers the overlapping area;

[0010] The width of the insulating layer along the radial direction is d1, the width of the overlapping area along the radial direction is d2, and the value range of d1 / d2 satisfies: 1.1≤d1 / d2≤5.

[0011] Beneficial effect: By setting an insulating layer between the second current collector and the pole, and making the projection of the insulating layer along the axial direction cover the overlapping area, the insulation effect of the second current collector and the pole is ensured, and the situation of short circuit caused by contact between the pole and the opposite-sex current collector is avoided. The width of the insulating layer in the radial direction must be sufficient to cover the overlapping area. If the width of the insulating layer in the radial direction is too small, the overlapping area will be exposed, and there is still a risk of contact between the pole and the opposite-sex current collector; if the width of the insulating layer in the radial direction is too large, it is easy to affect the heat dissipation of the cover plate assembly and the current collector assembly.

[0012] In a second aspect, the present invention further provides a battery pack including cylindrical batteries.

[0013] Because the battery pack includes cylindrical batteries, it has the same effect as the cylindrical batteries and will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 is a schematic diagram of a cylindrical battery of the present invention;

[0016] Figure 2 It is a schematic diagram of the exploded cylindrical battery of the present invention;

[0017] Figure 3 It is a schematic diagram of the current collecting assembly of the present invention in a disassembled state and the cover plate assembly;

[0018] Figure 4 It is a schematic diagram of the cover plate assembly of the present invention in a disassembled state and the current collecting assembly;

[0019] Figure 5 It is a schematic diagram of the coordination of the pole, the insulating layer and the current collecting assembly of the present invention;

[0020] Figure 6 It is a front view of the current collecting assembly and the cover plate assembly of the present invention;

[0021] Figure 7 For the present invention Figure 6 Schematic diagram of the cooperation between the current collecting assembly and the pole in the middle AA section state;

[0022] Figure 8 For the present invention Figure 6 Schematic diagram of the decomposition of the insulating layer, current collecting assembly and pole in the middle AA section state;

[0023] Description of reference numerals:

[0024] 1. Shell; 2. Battery cell; 21. First pole ear; 22. Second pole ear;

[0025] 3. Cover plate assembly; 31. Insulating layer; 32. Pole; 321. Flanged portion; 33. Cover plate body;

[0026] 4. Current collecting assembly; 41. First current collecting part; 42. Second current collecting part; 43. Assembly part; 44. Raised part. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0028] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0029] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0031] Combine the following Figures 1 to 8 , describing an embodiment of the present invention.

[0032] According to an embodiment of the present invention, on the one hand, a cylindrical battery is provided, comprising:

[0033] The battery cell 2 comprises a first pole tab 21 and a second pole tab 22 extending from the same end along the axial direction, and the first pole tab 21 and the second pole tab 22 have opposite polarities;

[0034] The cover plate assembly 3 includes a cover plate body 33 and a pole 32 that penetrates the cover plate body 33;

[0035] The current collecting assembly 4 is connected between the battery cell 2 and the cover plate assembly 3; the current collecting assembly 4 includes a first current collecting member 41 electrically connected to the first pole lug 21, and a second current collecting member 42 electrically connected to the second pole lug 22; the first current collecting member 41 is electrically connected to the pole 32, and the area of ​​the pole 32 inside the shell and the second current collecting member 42 are arranged on the same end surface of the battery cell 2; along the axial direction, the projection of the side of the pole 32 close to the battery cell 2 on the second current collecting member 42 at least partially overlaps with the second current collecting member 42 to form an overlapping area;

[0036] The insulating layer 31 is at least partially disposed between the second current collector 42 and the pole 32, and the projection of the insulating layer 31 on a plane perpendicular to the axis direction covers the overlapping area;

[0037] The width of the insulating layer 31 along the radial direction is d1, the width of the overlapping area along the radial direction is d2, and the value range of d1 / d2 satisfies: 1.1≤d1 / d2≤5.

[0038] It should be noted that, since the cylindrical battery is cylindrical, the axial direction of the battery cell 2 refers to the direction parallel to the axis of the cylinder. Specifically in this embodiment, the axial direction of the battery cell 2 refers to the direction parallel to the axis of the cylinder. Figure 2 Direction of arrow shown.

[0039] Since the end surface area of ​​the cylindrical battery is limited, the pole 32 and the opposite-sex current collector are in competition with each other in the radial direction, and both are led out from the same end, which easily leads to the problem of the pole 32 and the opposite-sex current collector contacting and causing a short circuit. For square-shell batteries, since the poles are arranged at both ends and there is a large distance between the poles, there will be no problem of opposite-sex contact causing a short circuit.

[0040] The cylindrical battery of this embodiment includes a cylindrical shell 1, and an opening is formed on at least one side of the shell 1 along the axial direction. The cover assembly 3 is covered on the opening of the shell 1. The shell 1 and the cover assembly 3 are sealed and connected to form a hollow cavity, and the battery cell 2 is arranged in the hollow cavity.

[0041] Since the first pole tab 21 and the second pole tab 22 are both led out from the same end of the battery cell 2 along the axial direction, the first pole tab 21 and the second pole tab 22 are spaced apart around the end surface of the battery cell 2 along the axial direction. In this embodiment, the first pole tab 21 and the second pole tab 22 are both constructed in a fan shape.

[0042] The cover plate assembly 3 is provided with a pole 32 . In this embodiment, the pole 32 is constructed as a cylindrical structure or a rotating body structure formed around an axis. The cover plate assembly 3 includes a cover plate body 33 . The pole 32 is arranged through the cover plate body 33 .

[0043] In order to facilitate the electrical connection between the battery cell 2 and the cover plate assembly 3, a current collecting assembly 4 is provided between the two so as to realize a transit connection.

[0044] The current collecting assembly 4 includes a first current collecting member 41 electrically connected to the first pole lug 21, and a second current collecting member 42 electrically connected to the second pole lug 22; one of the first current collecting member 41 and the second current collecting member 42 is electrically connected to the pole 32, and the projection of the other along the axial direction at least partially overlaps with the side of the pole 32 close to the battery cell 2 to form an overlapping area. Taking the electrical connection between the first current collecting member 41 and the pole 32 as an example, since the second current collecting member 42 needs to adapt to the shape of the second pole lug 22, and the internal space of the cylindrical battery is compact, at this time, the projection of the second current collecting member 42 along the axial direction at least partially overlaps with the side of the pole 32 close to the battery cell 2. If there is no overlapping area between the projection of the second current collecting member 42 along the axial direction and the side of the pole 32 close to the battery cell 2, it is easy to cause the cylindrical battery to be too large in size or the second pole lug 22 to be too small in size, which is not conducive to current transmission.

[0045] Combination Figure 3 As shown, the current collecting assembly 4 further includes an assembly part 43 , and the first current collecting part 41 and the second current collecting part 42 are installed together on the assembly part 43 , so that the current collecting assembly 4 forms a whole.

[0046] As an implementation form, the first current collector 41 may be a positive electrode current collector, and the second current collector 42 may be a negative electrode current collector. As another implementation form, the first current collector 41 may be a negative electrode current collector, and the second current collector 42 may be a positive electrode current collector.

[0047] When the projection of the second current collector 42 along the axial direction overlaps at least partially with the side of the pole 32 close to the battery cell 2 to form an overlapping area, since the second current collector 42 and the pole 32 carry opposite charges, the pole 32 and the opposite current collector may contact and cause a short circuit. Conversely, when the second current collector 42 is electrically connected to the pole 32, a similar situation will occur, which will not be described here. The following still takes the electrical connection between the first current collector 41 and the pole 32 as an example.

[0048] In this embodiment, an insulating layer 31 is provided between the second current collector 42 and the pole 32, and the projection of the insulating layer 31 on the plane perpendicular to the axial direction covers the overlapping area, thereby ensuring the insulation effect between the second current collector 42 and the pole 32, and avoiding the situation where the pole 32 contacts with the opposite current collector and causes a short circuit. The width of the insulating layer 31 in the radial direction must be sufficient to cover the overlapping area. If the width of the insulating layer 31 in the radial direction is too small, the overlapping area will be exposed, and there is still a risk of contact between the pole 32 and the opposite current collector; if the width of the insulating layer 31 in the radial direction is too large, it is easy to affect the heat dissipation of the cover plate assembly 3 and the current collector assembly 4.

[0049] This embodiment limits the lower limit of the ratio of the width d1 of the insulating layer 31 along the radial direction to the width d2 of the overlapping area along the radial direction, thereby ensuring that the width of the insulating layer 31 along the radial direction is sufficient to cover the overlapping area, avoiding the situation where the width of the insulating layer 31 along the radial direction is too small, avoiding the situation where the overlapping area is exposed, and reducing the risk of contact between the pole 32 and the opposite-sex current collector; and limits the upper limit of the ratio of the width d1 of the insulating layer 31 along the radial direction to the width d2 of the overlapping area along the radial direction, thereby avoiding the situation where the width of the insulating layer 31 along the radial direction is too large, which is easy to affect the heat dissipation of the cover plate assembly 3 and the current collecting assembly 4.

[0050] In some embodiments, the insulating layer 31 is disposed on a side of the cover body 33 facing the current collecting assembly 4 , and is at least partially disposed around the pole 32 .

[0051] In this embodiment, the insulating layer 31 is at least partially arranged around the pole 32, so that the insulating layer 31 can at least cover the overlapping area of ​​the pole 32 and the opposite-sex current collector, and by arranging the insulating layer 31 on the side of the cover body 33 facing the current collecting assembly 4, the insulation effect of the pole 32 and the opposite-sex current collector is ensured, thereby avoiding the situation where the pole 32 and the opposite-sex current collector come into contact and cause a short circuit.

[0052] In some embodiments, the insulating layer 31 is disposed around the pole 32 .

[0053] In this embodiment, the insulating layer 31 is constructed in an annular shape, and a hollow design is adopted in the middle so that the insulating layer 31 is arranged around the pole 32, which can ensure the insulation effect of the pole 32 and the opposite-sex current collector, make the insulation effect better, and avoid the pole 32 and the opposite-sex current collector from contacting and causing a short circuit. At the same time, it can make way for the connection between the protrusion 44 and the pole 32 to avoid interference and prevent the protrusion 44 from having poor contact with the pole 32.

[0054] In some embodiments, the insulating layer 31 is disposed discontinuously around the pole 32 .

[0055] In this embodiment, the insulating layer 31 is arranged on the side of the cover body 33 facing the current collecting assembly 4, so that the insulating layer 31 can at least cover the overlapping area of ​​the pole 32 and the opposite current collecting piece, thereby ensuring the insulation effect of the pole 32 and the opposite current collecting piece, and avoiding the situation where the pole 32 and the opposite current collecting piece contact and short circuit. The insulating layer 31 is arranged discontinuously around the pole 32 to ensure that there is a gap between the insulating layers 31, which can achieve a better heat dissipation effect.

[0056] In some embodiments, the width d1 of the insulating layer 31 along the radial direction satisfies the following range: 1 mm ≤ d1 ≤ 15 mm.

[0057] By limiting the lower limit of the width d1 of the insulating layer 31 in the radial direction, it is ensured that the width d1 of the insulating layer 31 in the radial direction is sufficient to cover the overlapping area, thereby avoiding the overlapping area from being exposed and avoiding the risk of contact between the pole 32 and the opposite-sex current collector. And by limiting the upper limit of the width d1 of the insulating layer 31 in the radial direction, it is possible to avoid the width of the insulating layer 31 in the radial direction being too large to easily affect the heat dissipation of the cover plate assembly 3 and the current collector assembly 4, thereby ensuring the heat dissipation effect.

[0058] In this embodiment, the width d1 of the insulating layer 31 along the radial direction may be 1 mm, 2 mm, 4 mm, 5 mm, 7 mm, 8 mm, 10 mm, 13 mm, 14 mm, 15 mm, etc.

[0059] In some embodiments, the vertical distance between the pole 32 and the side of the battery cell 2 and the second current collector 42 is d4, and the thickness of the insulating layer 31 is d3, which satisfies: 0 mm 2 <d3·d4≤3mm 2 .

[0060] Since the insulating layer 31 needs to ensure insulation between the pole 32 and the opposite current collector, the vertical distance d4 between the pole 32 and the second current collector 42 can be appropriately larger, thereby ensuring that the risk of conduction between the pole 32 and the second current collector 42 is small. At this time, the thickness of the insulating layer 31 can be appropriately smaller.

[0061] If the vertical distance d4 between the pole 32 and the second current collector 42 is close, the risk of conduction between the pole 32 and the second current collector 42 is relatively high. In this case, the thickness of the insulating layer 31 should be increased to ensure the insulation effect and reduce the risk of contact between the pole 32 and the opposite current collector.

[0062] In some embodiments, in combination Figure 8 As shown, one side of the pole 32 close to the battery core 2 is folded outward in the radial direction to form a flange portion 321 .

[0063] The cover body 33 is provided with a pole through hole. In the assembly stage, the pole 32 is passed through the pole through hole and folded to form a flange portion 321 , thereby fixing the pole 32 to both sides of the cover body 33 .

[0064] The pole 32 is disposed on one side of the battery cell 2 and has a groove formed radially inside the enclosed area of ​​the flange 321. Correspondingly, the first current collector 41 extends toward the pole 32 to form a protrusion 44, which is inserted into the groove and fixed by welding to achieve a fixed connection between the first current collector 41 and the pole 32.

[0065] In this embodiment, the insulating layer 31 is disposed in close contact with the flange portion 321 .

[0066] In some embodiments, in combination Figure 8 As shown, one of the first current collecting member 41 and the second current collecting member 42 extends toward the pole 32 to form a protrusion 44 , and the protrusion 44 is electrically connected to the pole 32 .

[0067] In some embodiments, the projection of the insulating layer 31 along the axial direction does not overlap with the protrusion 44 .

[0068] The first current collector 41 extends toward the pole 32 to form a protrusion 44, and the protrusion 44 is inserted into the groove and fixed by welding to achieve fixed connection between the first current collector 41 and the pole 32. In this embodiment, the projection of the insulating layer 31 along the axial direction does not overlap with the protrusion 44, so that the insulating layer 31 can be prevented from affecting the insertion of the protrusion into the pole pit, thereby preventing the protrusion 44 from having poor contact with the wall surface in the groove.

[0069] In order to ensure the welding effect, the protrusion 44 needs to fit tightly with the bottom wall of the groove.

[0070] In some embodiments, the thickness d3 of the insulating layer 31 is in the range of 0.02 mm≤d3≤0.5 mm.

[0071] When the thickness d3 of the insulating layer 31 is too thin, there is a risk of insulation failure. When the thickness d3 of the insulating layer 31 is too thick, the welding distance between the protrusion 44 and the bottom wall of the groove portion will be increased, resulting in the protrusion 44 being unable to fully contact the bottom wall of the groove portion, which can easily cause cold welding and affect the electrical connection between the first current collector 41 and the pole 32.

[0072] According to an embodiment of the present invention, on the other hand, a battery pack is provided, comprising the cylindrical battery as described above.

[0073] Obviously, the above embodiments are only examples for clear explanation, and are not intended to limit the implementation methods. Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the present invention.

Claims

1. A cylindrical battery, characterized in that: include: A battery cell (2), the battery cell (2) comprising a first pole lug (21) and a second pole lug (22) extending from the same end along an axial direction, and the first pole lug (21) and the second pole lug (22) have opposite polarities; A cover plate assembly (3), comprising a cover plate body (33) and a pole (32) disposed through the cover plate body (33); A current collecting assembly (4) connected between the battery cell (2) and the cover plate assembly (3); the current collecting assembly (4) comprises a first current collecting piece (41) electrically connected to the first pole lug (21), and a second current collecting piece (42) electrically connected to the second pole lug (22); the current collecting assembly (4) further comprises an assembly part (43), the first current collecting piece (41) and the second current collecting piece (42) being mounted together on the assembly part (43) so that the current collecting assembly (4) forms a whole; the first current collecting piece (41) is electrically connected to the pole (32), and the area of ​​the pole (32) inside the shell and the second current collecting piece (42) are arranged on the same end surface of the battery cell (2); along the axial direction, the projection of the side of the pole (32) close to the battery cell (2) on the second current collecting piece (42) at least partially overlaps with the second current collecting piece (42) to form an overlapping area; An insulating layer (31) is at least partially disposed between the second current collector (42) and the pole (32), wherein a projection of the insulating layer (31) on a plane perpendicular to the axis direction covers the overlapping area; The width of the insulating layer (31) along the radial direction is d1, the width of the overlapping area along the radial direction is d2, and the value range of d1 / d2 satisfies: 1.1≤d1 / d2≤5.

2. The cylindrical battery according to claim 1, characterized in that: The insulating layer (31) is arranged on a side of the cover plate body (33) facing the current collecting assembly (4), and is at least partially arranged around the pole (32).

3. The cylindrical battery according to claim 2, characterized in that: The insulating layer (31) is arranged around the pole (32).

4. The cylindrical battery according to claim 2, characterized in that: The insulating layer (31) is disposed discontinuously around the pole (32).

5. The cylindrical battery according to claim 1, characterized in that: The value range of the width d1 of the insulating layer (31) along the radial direction satisfies: 1 mm≤d1≤15 mm.

6. The cylindrical battery according to claim 1, characterized in that: The vertical distance between the side of the pole (32) close to the battery cell (2) and the second current collector (42) is d4, and the thickness of the insulating layer (31) is d3, satisfying: 0 mm 2 <d3·d4≤3mm 2 .

7. The cylindrical battery according to claim 1, characterized in that: The first current collecting member (41) extends toward the pole (32) to form a protrusion (44), and the protrusion (44) is electrically connected to the pole (32).

8. The cylindrical battery according to claim 7, characterized in that: The projection of the insulating layer (31) along the axial direction does not overlap with the protruding portion (44).

9. The cylindrical battery according to claim 8, characterized in that: The thickness d3 of the insulating layer (31) has a value range of 0.02 mm ≤ d3 ≤ 0.5 mm.

10. A battery pack, characterized in that: It comprises a cylindrical battery as described in any one of claims 1 to 9 above.

Images