Cylindrical battery shell and cylindrical lithium battery

Abstract

The utility model provides a cylindrical battery shell and a cylindrical lithium battery. The cylindrical battery shell comprises a shell body, the shell body comprises a bottom plate and a peripheral wall, the position, close to an opening, of the peripheral wall is concaved inwards in the circumferential direction to form a necking part, and the necking part comprises a first supporting part and a second supporting part which extend towards the center of an inner cavity and are in a flat plate shape; the first supporting part and the second supporting part are obliquely arranged towards one side of the bottom plate in the inward concave direction, and the included angle alpha between the first supporting part and the bottom plate and the included angle alpha between the second supporting part and the bottom plate are smaller than 10 degrees. Due to the fact that a certain collapse allowance is reserved on the necking part, a rolling groove can be conveniently designed in the previous rolling groove process, and a needed necking part structure can be conveniently formed. Meanwhile, the height of the necking part invading into the lower cavity of the shell body is small, so that the effective space of the lower cavity is ensured; and moreover, enough compression amount between the necking part and the cap assembly can be ensured, so that the sealing effect is ensured, and the safety of the lithium battery is improved.

Description

Technical Field

[0001] This application relates to the technical field of lithium-ion batteries, and particularly to a cylindrical battery case and a cylindrical lithium battery. Background Art

[0002] According to the packaging form, lithium batteries can be divided into three forms: square, cylindrical, and soft-pack. Among them, cylindrical lithium batteries have gradually become a research hotspot in lithium batteries due to their good consistency, high production efficiency, and strong heat dissipation ability at the system level, and are widely used in fields such as power tools, electric vehicles, and energy storage. It can be understood that cylindrical lithium batteries use a cylindrical battery case to encapsulate the battery core. Before and after the battery core is inserted into the case, a series of plastic processing operations need to be performed on the cylindrical battery case, including necking, grooving, and sealing.

[0003] In the related art, after the cylindrical battery case is sealed, it is expected that a necking portion with a flat structure can be formed by compression at the sealing position to seal the cap assembly well. However, due to the unreasonable structure design of the necking portion, it is difficult to achieve the above goal. For example, Figure 1 is a schematic diagram of the structure at the sealing position after the cylindrical battery case is sealed in the related art. As shown in FIGS. 1 and, at the sealing position of the case body 1, the necking portion 121 formed by the outer peripheral wall 12 of the case body 1 collapses severely. On the one hand, the collapse of the necking portion 121 will occupy the internal space of the cylindrical battery case and may even damage the wound core electrode group; on the other hand, the collapse of the necking portion 121 will also result in insufficient compression amount between it and the cap assembly 2 at point A, thereby leading to insufficient sealing performance of the seal. In the case of poor sealing at the seal, there is a risk of battery leakage and certain safety hazards. Summary of the Utility Model

[0004] The embodiments of this application provide a cylindrical battery case and a cylindrical lithium battery to at least solve the technical problem of poor sealing effect of the existing cylindrical battery case due to the unreasonable structure of the necking portion.

[0005] The first aspect embodiment of this application provides a cylindrical battery case, including:

[0006] It includes a case body, the case body includes a bottom plate and an outer peripheral wall, the top end of the outer peripheral wall has an opening, and the outer peripheral wall forms an inwardly concave necking portion along the circumferential direction near the opening;

[0007] Wherein, the necking portion includes a first support portion and a second support portion extending towards the center of the housing body. The necking portion further includes a connecting portion for connecting the first support portion and the second support portion. The outer surfaces of the first support portion, the second support portion, and the connecting portion jointly define a necking groove. Both the first support portion and the second support portion are provided at a certain inclination angle with respect to the bottom plate. Taking the larger of the angle between the first support portion and the bottom plate and the angle between the second support portion and the bottom plate as α, it satisfies: α < 10°.

[0008] The cylindrical battery housing according to the embodiment of the present application has at least the following beneficial effects:

[0009] In the cylindrical battery housing of the embodiment of the present application, by arranging the first support portion and the second support portion constituting the necking portion to be inclined towards the bottom plate direction, a certain amount of collapse margin has been reserved in the necking portion. Therefore, it is convenient to design the rolling groove in the previous rolling groove process to compress and form the required necking portion structure. At the same time, by controlling the inclination angle of the first support portion and the second support portion within 10°, the height of the necking portion invading into the lower cavity is small, ensuring the effective space of the lower cavity. And it can also ensure that there is enough compression amount between the necking portion and the cap assembly to ensure the sealing effect, so as to improve the safety of the lithium battery.

[0010] In a possible implementation manner, the included angle α satisfies: 1° < α < 5°. By reasonably designing the size of the included angle α, while reducing the difficulty of rolling groove design and facilitating the adjustment of the sealing process, it can also reduce the influence of the necking portion on the lower cavity space and ensure the sealing effect on the cap assembly.

[0011] In a possible implementation manner, taking the depth of the necking groove in the radial direction as H1 and the outer diameter of the housing body as D, it satisfies: 5% ≤ H1 / D ≤ 10%. By reasonably designing the depth of the necking groove, while ensuring that the cap assembly can be stably supported by the first support portion for smooth sealing, it can also improve the utilization rate of the internal space of the housing body and increase the energy density of the lithium battery.

[0012] In a possible implementation manner, taking the height of the necking groove as H2 and the height of the housing body as H, it satisfies: 0.2% ≤ H2 / H ≤ 0.5%. By reasonably designing the height H2 of the necking groove, while ensuring that the structural strength of the necking portion meets the requirements, it can also effectively improve the utilization rate of the internal space of the housing body and the processability of sealing.

[0013] In a possible implementation manner, the minimum wall thickness of the necking portion is T1, and the wall thickness of the housing body is T, satisfying: T1 / T ≥ 80%. By reasonably designing the wall thickness T1 at the thinnest part of the necking portion, the pressure resistance strength of the housing body can be ensured to meet the requirements.

[0014] In a possible implementation, T1 / T≥85%. By reasonably designing the wall thickness T1 at the thinnest part of the necking section, the pressure resistance of the housing body can be ensured to meet the requirements.

[0015] In a possible implementation, taking the minimum wall thickness of the necking section as T1, it satisfies: 0.1mm≤T1≤0.2mm. By setting the minimum wall thickness T1 of the necking section between 0.1mm and 0.2mm, the strength of the necking section can meet the pressure resistance requirements of a cylindrical battery housing with a common thickness.

[0016] In a possible implementation, taking the distance from the lowest point of the necking section to the upper surface of the bottom plate as L, and the height of the housing body as H, it satisfies: 90%≤L / H≤98%. By reasonably designing the distance L from the lowest point of the necking section located in the inner cavity to the upper surface of the bottom plate, while ensuring the sealing effect at the sealing position, the utilization rate of the internal space of the housing body can also be improved, and the energy density of the lithium battery can be increased.

[0017] The second aspect embodiment of the present application provides a cylindrical lithium battery, including the cylindrical battery housing of the first aspect embodiment above.

[0018] The cylindrical lithium battery according to the embodiment of the present application has at least the following beneficial effects:

[0019] The cylindrical lithium battery of the embodiment of the present application, due to having the cylindrical battery housing of the first aspect embodiment above, has the characteristics of good sealing effect and high safety.

[0020] In a possible implementation, it further includes a cap assembly, and the cap assembly is received by the necking section and sealed at the top of the housing body. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required to be used in the description of the embodiments of the present application. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 is a schematic cross-sectional view of a traditional cylindrical battery housing;

[0023] Figure 2 is a schematic view of the state of the cylindrical battery housing of an embodiment of the present application after sealing;

[0024] Figure 3 is Figure 2 a partial schematic view of part A in

[0025] Reference numerals:

[0026] 1 - housing body, 11 - bottom plate, 12 - outer peripheral wall, 121 - necking portion, 1211 - first support portion, 1212 - second support portion, 1213 - connecting portion, 122 - curled edge, 123 - opening, 124 - necking groove, 13 - inner cavity, 131 - upper cavity, 132 - lower cavity;

[0027] 2 - cap assembly. Detailed implementation manners

[0028] The embodiments of the present implementation manner will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals indicate the same or similar elements or elements with the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present implementation manner, and should not be construed as a limitation to the present implementation manner.

[0029] In the description of the present implementation manner, it should be understood that the orientation descriptions such as up, down, front, back, left, right, etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present implementation manner 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. Therefore, it should not be construed as a limitation to the present implementation manner.

[0030] In the description of the present implementation manner, the meaning of several is one or more, the meaning of multiple is more than two, greater than, less than, exceeding, etc. are understood as not including the present number, and above, below, within, etc. are understood as including the present number. If the first and second are described only for the purpose of distinguishing technical features, they should not be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or the sequence relationship of the indicated technical features.

[0031] In the description of the present implementation manner, unless otherwise clearly defined, words such as setting, installing, connecting, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in the present implementation manner in combination with the specific content of the technical solution.

[0032] It is understandable that a cylindrical lithium battery uses a cylindrical battery case to encapsulate the battery core. The cylindrical battery case is set to be closed at one end and open at the other end. The open end is used for the rolled core electrode group to enter the case, and the open end is closed through a sealing process to seal the cylindrical battery case. Thus, the sealing seals the cylindrical battery case and the cap assembly, isolating the entire rolled core electrode group and the electrolyte from the external environment. The rolled core electrode group and the electrolyte form a sealed electrochemical system inside the cylindrical battery case. It is understandable that the sealing process is a crucial process in the manufacturing process of cylindrical lithium batteries, and its process stability determines whether the battery's sealing is intact and reliable.

[0033] The following will Figure 2 be combined with Figure 3 to describe in detail the cylindrical battery case of the embodiments of the present application.

[0034] It should be noted that the cylindrical battery cases described in the embodiments of the present application hereinafter all refer to the cylindrical battery cases in the state where the sealing process has been completed. In this state, the cylindrical battery case is hermetically connected to the cap assembly at the top and encapsulates the rolled core electrode group in the inner cavity. For a concise understanding of the cylindrical battery case according to the embodiments of the present application, the rolled core electrode group and the cap assembly will not be elaborated in the following text.

[0035] In addition, it is understandable that the cylindrical battery case can be a nickel-plated steel case, which has advantages such as high pressure resistance. Of course, it is not limited to this. For example, it can also be an aluminum case. The following takes the cylindrical battery case using a nickel-plated steel case as an example for illustration. It can be formed by punching a steel strip, and the processing and manufacturing are simple and easy to scale production to reduce costs.

[0036] As Figure 2 shown in Figure 3 and

[0037] shown, the cylindrical battery case of this embodiment includes a case body 1. The case body 1 includes a bottom plate 11 and an outer peripheral wall 12. Among them, the bottom plate 11 is circular, and the outer peripheral wall 12 extends upward along the edge of the top surface of the bottom plate 11. The bottom plate 11 and the outer peripheral wall 12 jointly define an inner cavity 13. The top end of the outer peripheral wall 12 has an opening 123, and the opening 123 communicates with the inner cavity 13. At a position on the outer peripheral wall 12 close to the opening 123, a necking portion 121 is formed by inward concavity along the circumference. The necking portion 121 divides the inner cavity 13 into a mutually communicating upper cavity 131 and a lower cavity 132. The upper cavity 131 is used to accommodate the cap assembly 2, and the lower cavity 132 is used to accommodate the rolled core electrode group (not shown in the figure).

[0037] In this embodiment, the case body 1 includes an outer peripheral wall 12, and the outer contour of the outer peripheral wall 12 is cylindrical. Its outer diameter is the outer diameter of the cylindrical battery case, and this outer diameter determines the size series of the finally assembled cylindrical lithium battery. For example, a cylindrical battery case with an outer diameter of 21 mm is used to manufacture 21 series cylindrical lithium batteries, such as 2170 batteries.

[0038] It can be understood that in the sealing process, in addition to the inner concave formation of the necking portion 121 on the outer peripheral wall 12, a curled edge 122 will be formed at the top end. The curled edge 122, together with the necking portion 121 and the outer peripheral wall 12, realizes the sealed connection of the cap assembly 2. Specifically, the top surface of the necking portion 121 on one side of the inner cavity 13 is used to receive the cap assembly 2, and it is in contact connection with the bottom surface of the cap assembly 2. The inner wall surface of the part of the outer peripheral wall 12 between the necking portion 121 and the curled edge 122 is in contact connection with the outer peripheral surface of the cap assembly 2, and the inner wall surface of the curled edge 122 is in contact connection with the top surface of the cap assembly 2.

[0039] It can be understood that through the sealing process, the housing body 1 forms a necking portion 121 by inwardly concave along the circumferential direction at a position close to the opening 123. Specifically, the necking portion 121 includes a flat first support portion 1211 and a second support portion 1212 that extend toward the center of the inner cavity 13 and are parallel to each other, and a connecting portion 1213 for connecting the first support portion 1211 and the second support portion 1212, so as to Figure 2 In terms of the middle direction, the first support portion 1211 is located above the second support portion 1212. One ends of the first support portion 1211 and the second support portion 1212 close to the center of the inner cavity 13 are connected by the connecting portion 1213. The outer surfaces of the first support portion 1211, the second support portion 1212, and the connecting portion 1213 jointly define and form a necking groove 124. It can be understood that the inner surface of the first support portion 1211, that is, the top surface, is used to receive the cap assembly 2 and is in contact connection with the bottom surface of the cap assembly 2.

[0040] Although the above describes the connection of the first support portion 1211, the second support portion 1212, and the connecting portion 1213 to each other, it can be understood that the first support portion 1211, the second support portion 1212, and the connecting portion 1213 themselves are part of the wall portion of the outer peripheral wall 12. In the sealing process, the outer peripheral wall 12 undergoes plastic deformation of inward concavity at the position corresponding to the necking portion 121, thereby forming the first support portion 1211, the second support portion 1212, and the connecting portion 1213, that is, the first support portion 1211, the second support portion 1212, and the connecting portion 1213 are integral. Of course, in the previous process before the sealing process, a rolling groove can be cut at this position, for example, by the feeding movement of a hob and the rotational movement of the cylindrical battery housing, so that when sealing, the rolling groove undergoes plastic deformation to form the required necking portion 121.

[0041] In this embodiment, both the first support portion 1211 and the second support portion 1212 are in the shape of a flat plate, and the first support portion 1211 and the second support portion 1212 are inclined toward the bottom plate 11 along their concave directions. Specifically, when the first support portion 1211 and the second support portion 1212 are parallel to each other, taking the angle between the first support portion 1211 or the second support portion 1212 and the bottom plate 11 as α, it satisfies: α < 10°. It can be understood that in this case, since both the first support portion 1211 and the second support portion 1212 are in the shape of a flat plate and are parallel to each other, that is to say, the central plane of the necking groove 124 defined by the first support portion 1211, the second support portion 1212, and the connecting portion 1213 is inclined with respect to the surface of the bottom plate 11, and the inclination angle is not greater than 10°.

[0042] When the first support portion 1211 and the second support portion 1212 are not completely parallel to each other, then the relatively larger one of the angles between the first support portion 1211 or the second support portion 1212 and the bottom plate 11 is α, which satisfies: α < 10°. It can be understood that in this case, since the first support portion 1211 and the second support portion 1212 are not in a completely parallel state, at this time, both the angle between the first support portion 1211 and the bottom plate 11 and the angle α between the second support portion 1212 and the bottom plate 11 are less than 10°.

[0043] It can be understood that the above-mentioned necking portion 121 has the following advantages:

[0044] First of all, by setting the first support portion 1211 and the second support portion 1212 that make up the necking portion 121 to be inclined toward the bottom plate 11, a certain amount of collapse margin has been reserved for the necking portion 121. Therefore, it is convenient to design the rolling groove in the previous rolling groove process and facilitate the formation of the required necking portion structure in the sealing process.

[0045] Secondly, the inclination angles of the first support portion 1211 and the second support portion 1212 do not exceed 10°, and the height at which the necking portion 121 intrudes into the lower cavity 132 of the housing body 1 is small, ensuring the effective space of the lower cavity 132 and also being able to avoid damaging the wound core electrode group.

[0046] Furthermore, since the inclination angles of the first support portion 1211 and the second support portion 1212 do not exceed 10°, the top surface of the necking portion 121 located in the inner cavity 13, that is, the top surface of the first support portion 1211, is basically horizontal, and its contact area with the bottom surface of the cap assembly 2 is large, and there is sufficient compression amount between the two, with good sealing effect and being able to improve the safety of the lithium battery.

[0047] Further, in some embodiments, the included angle α satisfies: 1° < α < 5°. It can be understood that the included angle α affects the design difficulty of the rolling groove, the utilization rate of the inner cavity 13 of the housing body 1, and the sealing effect on the cap assembly 2. If α is too large, although the design difficulty of the rolling groove is small, the utilization rate of the inner cavity 13 of the housing body 1 will decrease, and the sealing effect on the cap assembly 2 will become poor; conversely, if α is too small, it is difficult to design the rolling groove, and the forming difficulty of the necking portion 121 is large. By reasonably designing the size of the included angle α, while reducing the design difficulty of the rolling groove, it is also possible to reduce the influence of the necking portion 121 on the space of the lower cavity 132 and ensure the sealing effect on the cap assembly 2.

[0048] In some embodiments, taking the depth of the necking groove 124 in the radial direction as H1 and the outer diameter of the housing body 1 as D, where 5% ≤ H1 / D ≤ 10%. It can be understood that if the depth H1 of the necking groove 124 is too large, that is, H1 / D is too large, the necking portion 121 will excessively invade the inner cavity 13 in the radial direction, resulting in a smaller inner diameter of the inner cavity 13 at the necking portion 121, causing waste of space, and also weakening the structural rigidity of the necking portion 121 itself, increasing stress, and there is a risk of cutting and cracking, which further leads to the inability to guarantee the sealing performance; conversely, if the depth H1 of the necking groove 124 is too small, that is, H1 / D is too small, the cap assembly 2 cannot be stably carried by the first supporting portion 1211, and the dimensional chain matching between the two is poor. When sealing, the cap assembly 2 may directly pass through the notch defined by the necking portion 121 and enter the lower cavity 132. By reasonably designing the depth of the necking groove 124, while ensuring that the cap assembly 2 can be stably carried by the first supporting portion 1211 for smooth sealing, it can also improve the utilization rate of the internal space of the housing body 1 and the energy density of the lithium battery.

[0049] In some embodiments, taking the height of the necking groove 124 as H2 and the height of the housing body 1 as H, where 0.2% ≤ H2 / H ≤ 0.5%. It can be understood that if the height H2 of the necking groove 124 is too large, it will waste the height of the housing body 1 and result in a smaller energy density of the lithium battery; conversely, if the height H2 of the necking groove 124 is too small, the stress at the connecting portion 1213 is likely to concentrate, and there is a risk of breakage at the necking portion 121 at this position, and the sealing process is also more difficult, resulting in a decrease in the yield rate. By reasonably designing the height H2 of the necking groove 124, while ensuring that the structural strength of the necking portion 121 meets the requirements, it can also effectively improve the utilization rate of the internal space of the housing body 1 and the processability of the sealing process. It can also be understood that, as Figure 3 shown, the height H2 described here refers to the height at the opening of the necking groove 124. Of course, if the first supporting portion 1211 and the second supporting portion 1212 are set to be parallel, the height inside the necking groove 124 will be the same as this height H2.

[0050] It can be understood that during the sealing process, the wall thicknesses of the first support portion 1211, the second support portion 1212, and the connecting portion 1213 will change as the material undergoes plastic deformation. To ensure the pressure resistance of the cylindrical battery housing, in some embodiments, the minimum wall thickness of the necking portion 121 is T1, and the wall thickness of the housing body 1 is T, where T1 / T ≥ 80%, and more preferably, T1 / T ≥ 85%. It can be understood that this minimum wall thickness T1 may occur on any one of the first support portion 1211, the second support portion 1212, and the connecting portion 1213. It can also be understood that if T1 / T is less than 80%, the safety margin of the mechanical strength of the cylindrical battery housing is insufficient. For example, when the internal air pressure of the cylindrical battery housing increases, it may cause the cylindrical battery housing to tear at this location. By reasonably designing the wall thickness T1 at the thinnest part of the necking portion 121, the pressure resistance of the housing body 1 can be ensured to meet the requirements.

[0051] In some embodiments, to ensure the pressure resistance of the cylindrical battery housing, in some embodiments, the minimum wall thickness of the necking portion 121 is T1, where 0.1 mm ≤ T1 ≤ 0.2 mm. It can be understood that setting the minimum wall thickness T1 of the necking portion 121 between 0.1 mm and 0.2 mm enables the necking portion 121 to meet the pressure resistance requirements of cylindrical battery housings with common wall thicknesses. For example, for a cylindrical battery housing with a wall thickness of 0.2 mm, the minimum wall thickness T1 of the necking portion 121 can be 0.17 mm.

[0052] In some embodiments, the distance from the lowest point of the necking portion 121 located in the inner cavity 13 to the upper surface of the bottom plate 11 is L, and the height of the housing body 1 is H, satisfying: 90% ≤ L / H ≤ 98%. It can be understood that if the distance L from the lowest point of the necking portion 121 to the upper surface of the bottom plate 11 is too large, that is, L / H is too large, it will affect the height of the upper cavity 131 and result in a poor sealing effect; conversely, if the distance L from the lowest point of the necking portion 121 to the upper surface of the bottom plate 11 is too small, that is, L / H is too small, it will affect the height of the lower cavity 132 and waste the height of the housing body 1, resulting in a decrease in the energy density of the lithium battery. By reasonably designing the distance L from the lowest point of the necking portion 121 located in the inner cavity 13 to the upper surface of the bottom plate 11, while ensuring the sealing effect at the sealing location, the utilization rate of the internal space of the housing body 1 can also be improved, and the energy density of the lithium battery can be increased.

[0053] The embodiment of the present application also provides a cylindrical lithium battery, which includes the cylindrical battery housing of the above embodiment. Due to having the cylindrical battery housing of the above embodiment, therefore, the sealing structure formed after sealing the cylindrical lithium battery of this embodiment is safe and reliable.

[0054] It can be understood that in this cylindrical lithium battery, the cylindrical battery housing is hermetically connected to the cap assembly 2 at the top, and the wound core electrode group is encapsulated in the inner cavity 13. Moreover, the cap assembly 2 is received and sealed by the necking portion 121 at the top of the cylindrical battery housing.

[0055] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of this implementation. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0056] Although the embodiments of this implementation have been shown and described, those of ordinary skill in the art can understand that: various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and purposes of this implementation, and the scope of this implementation is defined by the claims and their equivalents.

Claims

1. A cylindrical battery housing, characterized in that: include: The invention comprises a shell body (1), wherein the shell body comprises a bottom plate (11) and an outer peripheral wall (12), wherein the top end of the outer peripheral wall (12) has an opening (123), and the outer peripheral wall (12) is concave inwardly along the circumferential direction at a position close to the opening (123) to form a constricted portion (121); The necking portion (121) comprises a first supporting portion (1211) and a second supporting portion (1212) extending toward the center of the shell body (1); the necking portion (121) further comprises a connecting portion (1213) for connecting the first supporting portion (1211) and the second supporting portion (1212); the outer surfaces of the first supporting portion (1211), the second supporting portion (1212) and the connecting portion (1213) jointly define a necking groove (124); and the first supporting portion (1211) and the second supporting portion (1212) are both provided with a certain inclination angle with the bottom plate (11); the larger of the angles between the first supporting portion (1211) and the bottom plate (11) and the angles between the second supporting portion (1212) and the bottom plate (11) is α, and the following condition is satisfied: α<10°.

2. The cylindrical battery housing according to claim 1, characterized in that: The included angle α satisfies: 1°<α<5°.

3. The cylindrical battery housing according to claim 1, characterized in that: The depth of the shrinkage groove (124) in the radial direction is H1, and the outer diameter of the shell body (1) is D, and the following is satisfied: 5%≤H1 / D≤10%.

4. The cylindrical battery housing according to claim 1, characterized in that: The height of the shrinkage groove (124) is denoted as H2, and the height of the shell body (1) is denoted as H, and the following condition is satisfied: 0.2%≤H2 / H≤0.5%.

5. The cylindrical battery housing according to claim 1, characterized in that: The minimum wall thickness of the necked portion (121) is T1, and the wall thickness of the shell body (1) is T, satisfying: T1 / T≥80%.

6. The cylindrical battery housing according to claim 5, characterized in that: T1 / T≥85%.

7. The cylindrical battery housing according to any one of claims 1 to 5, characterized in that: The minimum wall thickness of the necked portion (121) is T1, which satisfies the following condition: 0.1 mm ≤ T1 ≤ 0.2 mm.

8. The cylindrical battery housing according to any one of claims 1 to 5, characterized in that: The distance between the lowest point of the necked portion (121) and the upper surface of the bottom plate (11) is L, and the height of the shell body (1) is H, satisfying: 90%≤L / H≤98%.

9. A cylindrical lithium battery, characterized in that: Comprising the cylindrical battery casing according to any one of claims 1 to 8.

10. The cylindrical lithium battery according to claim 9, characterized in that: It also comprises a cap assembly (2), wherein the cap assembly (2) is received by the necking portion (121) and sealed on the top of the shell body (1).

Images