Cylindrical battery and battery module

Abstract

The utility model provides a cylindrical battery and a battery module, and relates to the technical field of batteries. The cylindrical battery comprises a shell, a battery cell and a pole, the shell comprises an end cover and a lower shell, the lower shell is provided with a containing groove and an opening, the opening is communicated with the containing groove, the end cover covers the opening in a sealing mode, so that a cavity is defined by the end cover and the lower shell, and the end cover is provided with an avoiding hole; the battery cell is located in the cavity and comprises a first end face facing the end cover, the first end face is provided with a first tab and a second tab, and the first tab is in direct contact with and electrically connected with the end cover; and the pole penetrates through the avoiding hole and is electrically connected with the second tab, and the pole and the end cover are arranged in an insulated manner. The structure of the cylindrical battery is simpler.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a cylindrical battery and a battery module. Background Technology

[0002] Cylindrical batteries (such as cylindrical lithium-ion batteries) have advantages such as ease of standardization, high pack compatibility, and good safety. In recent years, more and more electric vehicles have adopted cylindrical batteries as their power batteries.

[0003] To further improve the safety, reduce the impedance, and increase the volumetric energy density of cylindrical batteries, their structures are becoming increasingly complex and their fabrication increasingly difficult. Utility Model Content

[0004] The embodiments of this application provide a cylindrical battery and a battery module with a simpler structure.

[0005] To achieve the above objectives, the embodiments of this application adopt the following technical solutions:

[0006] On one hand, a cylindrical battery is provided, comprising a casing, a cell, and terminals. The casing includes an end cap and a lower casing. The lower casing has a receiving groove and an opening, the opening communicating with the receiving groove. The end cap covers the opening, forming a cavity with the end cap and the lower casing. The end cap has a clearance hole. The cell is located within the cavity and includes a first end face facing the end cap. The first end face has a first tab and a second tab. The first tab is in direct contact with and electrically connected to the end cap. The terminals pass through the clearance hole and are electrically connected to the second tab. The terminals are insulated from the end cap.

[0007] In some embodiments, the height by which the first electrode protrudes from the first end face is a first height, and the height by which the second electrode protrudes from the first end face is a second height, wherein the first height is greater than the second height.

[0008] In some embodiments, the end cap includes a raised region that faces the first tab, the raised region protruding toward the surface of the end cap toward the battery cell and abutting against the first tab.

[0009] In some embodiments, the protruding region presses against the middle region of the first tab, causing the first tab to have a recessed region. The first tab has a first contact area and a second contact area, with the first contact area surrounding the second contact area, thereby forming the recessed region on the first tab. The first contact area is connected to a position on the end cap located on both sides of the protruding region, and the second contact area abuts against the lower surface of the protruding region.

[0010] In some embodiments, the end cap has a circular outline, the clearance hole is located on one side of the center of the circular outline of the end cap, and the protruding area is located on the other side of the center of the circular outline of the end cap.

[0011] In some embodiments, the protruding region has an arc-shaped outline; and the protruding region extends along the direction of the center of the circular outline of the end cap, or the protruding region extends along an arc-shaped direction centered on the pole post.

[0012] In some embodiments, the raised area is formed by stamping the outer surface of the end cap facing the cell, and a groove is formed on the outer surface of the end cap.

[0013] In some embodiments, the raised region is welded to the first electrode tab.

[0014] In some embodiments, a collector plate is provided between the pole post and the second pole tab.

[0015] On the other hand, a battery module is provided, including the cylindrical battery.

[0016] The single-cell battery and battery module provided in this application embodiment have a first tab that is in direct contact and electrically connected to the end cap. Since the first tab is in direct contact and electrically connected to the end cap, that is, the first tab is electrically connected to the external circuit through the end cap, there is no need to set up a current collector or terminal post electrically connected to the first tab, which reduces the number of parts in the single-cell battery and simplifies the assembly process of the single-cell battery. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A cross-sectional schematic diagram of a cylindrical battery provided in an embodiment of this application;

[0019] Figure 2 A top view of a cylindrical battery provided in an embodiment of this application;

[0020] Figure 3 for Figure 1 A magnified view of the area at point I;

[0021] Figure 4 This is a cross-sectional schematic diagram of a housing in an embodiment of this application;

[0022] Figure 5 This is a cross-sectional schematic diagram of a battery cell according to an embodiment of this application;

[0023] Figure 6 This is a top view of a battery cell according to an embodiment of this application;

[0024] Figure 7 This is a cross-sectional schematic diagram of a battery cell according to an embodiment of this application;

[0025] Figure 8 A top view of a cylindrical battery provided for another embodiment of this application.

[0026] Figure label:

[0027] 10-Housing; 20-Cell; 30-Terminal; 40-Current collector; 50-Insulating sleeve;

[0028] 10a - cavity; 20a - first end face;

[0029] 11-End cap; 12-Lower shell;

[0030] 21-First electrode ear; 22-Second electrode ear; 23-Body body;

[0031] 211 - First contact area; 212 - Second contact area;

[0032] 111 - Raised area; 112 - Clearance hole Detailed Implementation

[0033] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0034] In the embodiments of this application, the terms "first", "second", "third", "fourth" are used to distinguish the same or similar items with essentially the same function and effect, only for the purpose of clearly describing the technical solution of the embodiments of this application, and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated.

[0035] In the embodiments of this application, "multiple" means two or more, and "at least one" means one or more, unless otherwise explicitly defined.

[0036] In the embodiments of this application, the terms "upper" and "lower" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0037] This application provides a battery module, which can be a power battery module used in electric vehicles to provide power to the drive motor and other components of the electric vehicle. Of course, the battery module can also be other types, such as those used in electric bicycles and electric motorcycles. This application does not limit the type or application scenario of the battery module.

[0038] A battery module may include a housing and individual battery cells housed within the housing. The housing protects the individual battery cells from impacts. The housing may have mounting cavities where the individual battery cells are installed. The battery module may include multiple individual battery cells arranged in an array. When multiple individual battery cells are housed within the housing, they can be connected in series or in parallel.

[0039] In practical applications, the enclosure can be equipped with a charging interface for charging and a discharging interface for discharging. The mounting cavity inside the enclosure can also house modules such as a battery management system.

[0040] The single cell is a cylindrical cell (such as a cylindrical lithium-ion cell). Cylindrical cells have advantages such as easy standardization, high compatibility in battery packs, and good safety. In recent years, more and more electric vehicles have adopted cylindrical cells as their power batteries.

[0041] Figure 1 This is a cross-sectional schematic diagram of a cylindrical battery provided as an embodiment of this application. Figure 1 As shown, the cylindrical battery includes a casing 10, a cell 20, and terminals 30.

[0042] The housing 10 is used to house or connect other components of the cylindrical battery. For example, the battery cell 20, electrolyte, etc. are disposed inside the housing 10, so that the housing 10 serves to house and protect the battery cell 20 and electrolyte. As another example, the terminal post 30 is connected to the housing 10 to keep the terminal post 30 fixed.

[0043] Figure 4 This is a cross-sectional schematic diagram of a housing 10 according to an embodiment of this application. Figure 1 and Figure 4As shown, the housing 10 may include an end cap 11 and a lower housing 12. The lower housing 12 is provided with a receiving groove, and the end cap 11 covers the opening end of the receiving groove, so that the end cap 11 and the lower housing 12 form a cavity 10a. The battery cell 20, electrolyte, etc. are disposed inside the cavity 10a, and the electrode post 30 is connected to the end cap 11.

[0044] Exemplarily, the lower shell 12 includes a side wall and a bottom wall. The side wall is cylindrical, forming a cylindrical space open at both ends. The bottom wall covers one end of the side wall, so that the side wall and the bottom wall together form a receiving groove open at one end. The end cap 11 is circular, covering the other end of the side wall (i.e., covering the open end of the receiving groove), so that the end cap 11 and the lower shell 12 together form a cavity 10a. The lower shell 12 can be an integral structure, for example, the side wall and the bottom wall can be integrally formed from sheet metal parts by a stamping process.

[0045] In practical applications, the end cap 11 and the lower shell 12 can be welded together. For example, after placing components such as the battery cell 20 and electrolyte inside the cavity 10a, the end cap 11 is assembled to the opening end of the receiving groove, and the edge of the end cap 11 is welded to the edge of the side wall to achieve the connection between the end cap 11 and the lower shell 12 and the sealing of the cavity 10a.

[0046] The housing 10 can be made of metal. For example, the housing 10 is made of aluminum alloy.

[0047] Figure 5 This is a cross-sectional schematic diagram of a battery cell 20 according to an embodiment of this application. Figure 5 As shown, the battery cell 20 includes a first end face 20a facing the end cap 11, and the first end face 20a is provided with a first tab 21 and a second tab 22.

[0048] The cell 20 includes multiple film layers wound into a cylindrical shape. Each film layer includes an edge facing the end cap 11 (e.g., an edge in the film layer that connects to the first tab 21 and the second tab 22), and the edges of the multiple film layers facing the end cap 11 are wound to form a first end face 20a.

[0049] Figure 6 This is a top view of a battery cell according to an embodiment of this application. Figure 6 As shown, the first electrode 21 and the second electrode 22 have different polarities. For example, the first electrode 21 is a positive electrode and the second electrode 22 is a negative electrode; or, the first electrode 21 is a negative electrode and the second electrode 22 is a positive electrode. This application does not limit the specific polarity of the first electrode 21 and the second electrode 22. For ease of description, the following example only illustrates the situation where the first electrode 21 is a negative electrode and the second electrode 22 is a positive electrode.

[0050] The first electrode 21 and the second electrode 22 are provided to protrude from the first end face 20a, that is, the first electrode 21 and the second electrode 22 are located on the side of the first end face 20a facing the end cover 11.

[0051] The first tab 21 and the second tab 22 are located on the same side of the cell 20, which can reduce the internal resistance of the single cell and thus reduce the heat generation of the single cell. Furthermore, since the end of the casing 10 away from the end cap 11 does not need to reserve space for the tabs, the volume of the cell 20 can be increased without changing the volume of the cavity 10a, thereby increasing the volumetric energy density of the single cell.

[0052] Continue to refer to Figure 1 and Figure 4 The end cap 11 is provided with a clearance hole 112, and the pole post 30 passes through the clearance hole 112 and is electrically connected to the second pole tab 22. The pole post 30 is insulated from the end cap 11. The second pole tab 22 is electrically connected to an external circuit through the pole post 30.

[0053] For example, the single cell also includes an insulating sleeve 50, which is located between the edge of the terminal post 30 and the clearance hole 112. For example, the insulating sleeve 50 is made of a polymer material, which achieves insulation between the terminal post 30 and the end cap 11 by preventing contact between the terminal post 30 and the end cap 11. In practical applications, the insulating sleeve 50 can be formed by filling the gap between the terminal post 30 and the edge of the clearance hole 112 with polymer material.

[0054] The pole post 30 and the second tab 22 can be directly electrically connected. Alternatively, the pole post 30 and the second tab 22 can be welded together.

[0055] The terminal 30 and the second tab 22 can also be electrically connected via other adapters. Exemplarily, the single-cell battery also includes a current collector 40 connected between the terminal 30 and the second tab 22. In practical applications, the current collector 40 can be soldered onto the second tab 22 first, and then the terminal 30 can be soldered to the current collector 40. Compared to soldering the terminal 30 directly to the second tab 22, soldering the terminal 30 to the current collector 40 is less likely to burn through the second tab 22, thus protecting the cell 20.

[0056] It should be noted that the end of the terminal post 30 furthest from the cell 20 can protrude from the end cap 11, thereby facilitating the electrical connection between the single cell and the external circuit.

[0057] Continue to refer to Figure 1The first tab 21 is in direct contact with and electrically connected to the end cap 11. For example, the side of the end cap 11 facing the battery cell 20 is in direct contact with and electrically connected to the first tab 21. An external circuit can be electrically connected to the battery cell 20 via electrical connections to the housing 10 and the terminal post 30, thereby enabling the charging and discharging of the battery cell 20. For example, one connecting wire is electrically connected to the housing 10, and the other connecting wire is electrically connected to the terminal post 30.

[0058] Since the first tab 21 is in direct contact with and electrically connected to the end cap 11, that is, the first tab 21 is electrically connected to the external circuit through the end cap 11, there is no need to set up the current collector 40 and the terminal post 30 which are electrically connected to the first tab 21, which reduces the number of parts of the single cell and simplifies the assembly process of the single cell.

[0059] In addition, by eliminating components such as the current collector 40 and the terminal post 30 that are electrically connected to the first electrode 21, the weight of a single battery cell is reduced without changing the cell 20, thereby increasing the weight energy density of the single battery cell; and with the cavity 10a volume remaining unchanged, there is more space available to place the cell 20, thereby increasing the volume energy density of the single battery cell.

[0060] For example, the first electrode tab 21 is welded to the end cap 11.

[0061] Continue to refer to Figure 5 The height of the first electrode tab 21 protruding from the first end face 20a is the first height H, and the height of the second electrode tab 22 protruding from the first end face 20a is the second height h. The first height H can be greater than the second height h.

[0062] Since the first tab 21 is in direct contact with the end cap 11, and the second tab 22 is electrically connected to the collector plate 40, and the collector plate 40 is located between the end cap 11 and the second tab 22, space needs to be reserved between the end cap 11 and the second tab 22 to accommodate the collector plate 40. Therefore, the height of the second tab 22 needs to be less than the height of the first tab 21, so that a space for accommodating the collector plate 40 is formed between the second tab 22 and the end cap 11.

[0063] When the end of the electrode post 30 facing the cell 20 extends into the cavity 10a, space needs to be reserved between the end cap 11 and the second electrode tab 22 to accommodate the electrode post 30. For example, the height difference δ between the first height H and the second height h is equal to the sum of the thickness of the current collector 40 and the length of the electrode post 30 extending into the cavity 10a.

[0064] For example, the height difference δ between the first height H and the second height h is greater than 0 and less than or equal to 4 mm. For instance, the height difference δ between the first height H and the second height h is any value among 1 mm, 2 mm, 3 mm, and 4 mm, or a value within a range of any two values.

[0065] It should be noted that the above description only assumes that the end cap 11 is approximately flat and parallel to the first end face 20a. In actual applications, the end cap 11 can also be an arc surface or a stepped surface, and the end cap 11 can also be inclined relative to the first end face 20a.

[0066] For example, when the end cap 11 is tilted relative to the first end face 20a, the distance between the area of ​​the end cap 11 opposite to the first electrode tab 21 and the first end face 20a is smaller, while the distance between the area of ​​the end cap 11 opposite to the second electrode tab 22 and the first end face 20a is larger. In this case, the first height H can also be equal to or less than the second height h, which can still achieve direct contact and electrical connection between the first electrode tab 21 and the end cap 11, and the second electrode tab 22 can be electrically connected to the electrode post 30 through the current collector 40.

[0067] Continue to refer to Figures 1 to 4 The end cap 11 may include a raised area 111, which is directly opposite the first tab 21 and protrudes from the surface of the end cap 11 toward the cell 20 toward the first tab 21.

[0068] For example, the area of ​​the end cap 11 opposite to the first tab 21 is stamped toward the cell 20 to form a protruding area 111. For example, the area of ​​the end cap 11 opposite to the first tab 21 is recessed toward the cell 20 by stamping.

[0069] For example, the depth d of the recess formed by the protrusion 111 being stamped toward the battery cell 20 is 2 mm.

[0070] Alternatively, the end cap 11 may have a protrusion on the side facing the battery cell 20, with the protrusion opposite to the first electrode tab 21 and protruding from the surface of the end cap 11 facing the battery cell 20. The protrusion may be an integral part of the end cap 11 or may be connected to the end cap 11 by welding.

[0071] The raised area 111 abuts against the first electrode tab 21. For example, the raised area 111 protrudes towards the cell 20, and when the end cover 11 is assembled to the lower shell 12, the raised area 111 presses against the first electrode tab 21.

[0072] The mutual compression between the protruding region 111 and the first tab 21 makes the contact between the end cap 11 and the first tab 21 more reliable. Furthermore, the contact between the protruding region 111 and the first tab 21 can reduce or eliminate the impact of dimensional errors in the housing 10 and the first tab 21. For example, when the first height H of the first tab 21 is less than the theoretical value, the protruding region 111 can still contact the first tab 21 because it protrudes from the surface of the end cap 11 facing the cell 20; when the first height H of the first tab 21 is greater than the theoretical value, the protruding region 111 increases the amount of compression on the first tab 21 because it protrudes from the surface of the end cap 11 facing the cell 20.

[0073] For example, the raised area 111 is welded to the first electrode tab 21.

[0074] The area of ​​the raised region 111 can be smaller than the projected area of ​​the first tab 21 on the end cap 11. Figure 7 This is a cross-sectional schematic diagram of a battery cell according to an embodiment of this application. For example, as shown... Figure 7 As shown, the protruding region 111 presses against the central region of the first electrode tab 21, causing the first electrode tab 21 to have a recessed region. The first electrode tab 21 has a first contact area 211 and a second contact area 212. The first contact area 211 surrounds the second contact area 212, thus forming a recessed region in the first electrode tab 21. The first contact area 211 is connected to the end cap 11 at positions located on both sides of the protruding region 111, and the second contact area 212 abuts against the lower surface of the protruding region 211.

[0075] The raised area 111 cooperates with the recessed area to increase the connection area between the raised area 111 and the first electrode 21, and reduce the connection resistance between the end cover 11 and the first electrode 21. Furthermore, after the recessed area is formed by stamping, the raised area 111 can restrict the position of the first electrode 21, so that the first electrode 21 and the raised area 111 can move relative to each other.

[0076] Figure 2 This is a top view of a cylindrical battery provided as an embodiment of this application. Figure 2 As shown, the end cap 11 has a circular outline. A clearance hole 112 is located on one side of the center of the circular outline of the end cap 11, and a raised area 111 is located on the other side of the center of the circular outline of the end cap 11. That is, the raised area 111 and the clearance hole 112 are located on opposite sides of the center. Since the first electrode tab 21 is connected to the raised area 111, and the second electrode tab 22 is connected to the electrode post 30 located within the clearance hole 112, the raised area 111 and the clearance hole 112 are located on opposite sides of the center, respectively, increasing the distance between the first electrode tab 21 and the second electrode tab 22.

[0077] Furthermore, the individual battery can be electrically connected to an external circuit through the end cap 11 and the terminal post 30. After the distance between the protruding area 111 and the terminal post 30 is increased, more space can be used to realize the electrical connection between the end cap 11 and the external circuit.

[0078] Continue to refer to Figure 2 The raised region 111 extends along the center of the circular outline of the end cap 11, and the outline of the raised region 111 is arc-shaped. The arc shape of the raised region 111 increases the connection area between the end cap 11 and the first electrode 21, thereby improving the connection reliability between the end cap 11 and the first electrode 21. Furthermore, when the raised region 111 is arc-shaped, a larger area is formed between the raised region 111 and the electrode post 30, which can be used for the electrical connection between the end cap 11 and the external circuit.

[0079] Continue to refer to Figure 2 The end cap 11 and the raised area 111 are concentric, that is, the raised area 111 extends along the edge of the end cap 11, forming a large area between the raised area 111 and the pole post 30. This area can be used for the electrical connection between the end cap 11 and the external circuit.

[0080] As an alternative to this embodiment, please refer to Figure 8 The protruding region 111 has an arc-shaped outline and extends along an arc-shaped direction centered on the pole post 30. For cylindrical batteries using a full-tab wound cell 20, the protruding region 111 extends along an arc-shaped direction centered on the pole post 30, allowing it to connect with the first tabs 21 on more winding layers, further reducing the internal weight of the battery.

[0081] For example, continue to refer to Figure 6 The first electrode 21 and the second electrode 22 can be fan-shaped, and the raised area 111 can be arc-shaped, and the center of the fan-shaped first electrode 21 coincides with the center of the raised area 111.

[0082] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A cylindrical battery, characterized in that, include: The housing (10) includes an end cap (11) and a lower shell (12). The lower shell (12) is provided with a receiving groove and an opening. The opening and the receiving groove are connected. The end cap (11) covers the opening so that the end cap (11) and the lower shell (12) form a cavity (10a). The end cap (11) is provided with a clearance hole (112). The battery cell (20) is located inside the cavity (10a). The battery cell (20) includes a first end face (20a) facing the end cap (11). The first end face (20a) is provided with a first tab (21) and a second tab (22). The first tab (21) is in direct contact with and electrically connected to the end cap (11). The pole (30) passes through the clearance hole (112) and is electrically connected to the second electrode (22). The pole (30) is insulated from the end cap (11).

2. The cylindrical battery according to claim 1, characterized in that, The height of the first tab (21) protruding from the first end face (20a) is the first height (H), and the height of the second tab (22) protruding from the first end face (20a) is the second height (h). The first height (H) is greater than the second height (h).

3. The cylindrical battery according to claim 1, characterized in that, The end cap (11) includes a raised area (111) which is directly opposite the first tab (21). The raised area (111) protrudes from the surface of the end cap (11) facing the cell (20) and abuts against the first tab (21).

4. The cylindrical battery according to claim 3, characterized in that, The protruding area (111) presses against the middle area of ​​the first electrode tab (21), causing the first electrode tab (21) to have a recessed area. The first electrode tab (21) has a first contact area (211) and a second contact area (212). The first contact area (211) surrounds the second contact area (212), causing the first electrode tab (21) to form the recessed area. The first contact area (211) is connected to the end cap (11) at a position on both sides of the protruding area (111). The second contact area (212) abuts against the lower surface of the protruding area (111).

5. The cylindrical battery according to claim 4, characterized in that, The end cap (11) has a circular outline, the clearance hole (112) is located on one side of the center of the circular outline of the end cap (11), and the protruding area (111) is located on the other side of the center of the circular outline of the end cap (11).

6. The cylindrical battery according to claim 5, characterized in that, The protruding area (111) has an arc-shaped outline; and the protruding area (111) extends along the direction of the center of the circular outline of the end cap (11), or the protruding area (111) extends along an arc-shaped direction with the pole post (30) as the center.

7. The cylindrical battery according to claim 3, characterized in that, The raised area (111) is formed by stamping the outer surface of the end cap (11) facing the battery cell (20), and a groove is formed on the outer surface of the end cap (11).

8. The cylindrical battery according to claim 3, characterized in that, The raised area (111) is welded to the first electrode tab (21).

9. The cylindrical battery according to claim 1, characterized in that, A collector plate (40) is provided between the pole post (30) and the second pole tab (22).

10. A battery module, characterized in that, Includes the cylindrical battery as described in any one of claims 1 to 9.

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