Cylindrical battery pack and battery device

Abstract

The embodiment of the utility model provides a cylindrical battery pack and a battery device, the cylindrical battery pack comprises a cylindrical battery and a conducting bar, the cylindrical battery comprises a shell and a pole, the pole is arranged on the shell end face of the shell, the wall thickness of the shell is smaller than the thickness of the pole in the axial direction of the cylindrical battery, and the conducting bar is arranged in the shell. The conducting bar comprises a pole connecting part and a shell connecting part, the pole connecting part is electrically connected with one side, far away from the shell, of the pole, the shell connecting part is electrically connected with the shell, the ratio of the thickness of the pole connecting part to the thickness of the shell connecting part is A, and A is larger than or equal to 0.5 and smaller than or equal to 0.9. According to the cylindrical battery pack, the connection strength of the pole and the conducting bar and the balance of the connection strength of the shell and the conducting bar can be guaranteed, the overcurrent capacity of the pole side can be guaranteed, and the shell can be prevented from being deformed in the connection process of the shell and the shell connection part.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery, in particular to a cylindrical battery pack and a battery device. BACKGROUND

[0002] The cylindrical battery pack comprises a cylindrical battery, and the cylindrical battery is provided with two output terminals with different polarities at one axial end. One output terminal is a pole, and the other output terminal is a shell of the cylindrical battery. The two output terminals are welded with the same conductive row, and the connection strength is unbalanced, so that the connection position of the output terminal with weak connection strength and the conductive row becomes a weak point prone to failure.

[0003] Therefore, how to balance the connection strength of the two output terminals and the conductive row is a technical problem to be solved by those skilled in the art. CONTENT OF THE UTILITY MODEL

[0004] To solve the above technical problem, the present application provides a cylindrical battery pack, which comprises a cylindrical battery and a conductive row. The cylindrical battery comprises a shell and a pole, the pole is arranged on the shell end face of the shell, the wall thickness of the shell is smaller than the thickness of the pole in the axial direction of the cylindrical battery, the conductive row comprises a pole connecting part electrically connected to the side of the pole away from the shell and a shell connecting part electrically connected to the shell, and the thickness ratio of the pole connecting part to the shell connecting part is A, and the range of A is 0.5≤A≤0.9.

[0005] The cylindrical battery pack provided by the present application controls the thickness ratio A of the pole connecting part to the shell connecting part within the range of 0.5-0.9, which can not only balance the connection strength of the pole and the conductive row and the connection strength of the shell and the conductive row, but also ensure the overcurrent capacity of the pole side and avoid the deformation of the shell during the electrical connection of the shell and the shell connecting part. If A is too large, the thickness of the shell connecting part is small and the thickness of the pole connecting part is large, which causes the connection strength of the shell connecting part and the shell to be weak and the connection strength of the pole connecting part and the pole to be strong, resulting in that the connection position of the shell connecting part and the shell becomes a weak point and is prone to failure. If A is too small, the thickness of the pole connecting part is small and the thickness of the shell connecting part is large, which causes the connection strength of the pole connecting part and the pole to be weak and the connection strength of the shell connecting part and the shell to be strong, resulting in that the connection position of the pole connecting part and the pole becomes a weak point and is prone to failure. Moreover, the small thickness of the pole connecting part also causes poor overcurrent capacity of the pole side. In addition, because the wall thickness of the shell is thinner than the thickness of the pole in the axial direction of the cylindrical battery, the large thickness of the shell connecting part can easily cause the deformation of the shell during the connection with the shell.

[0006] The battery device provided by the present application also has the above technical effects because it comprises the above cylindrical battery pack. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1 A top view of a partial structure of an embodiment of the battery device provided in this application;

[0008] Figure 2 for Figure 1 A three-dimensional view of the middle section structure;

[0009] Figure 3 for Figure 2 A three-dimensional view of the middle section structure;

[0010] Figure 4 for Figure 3 Exploded view;

[0011] Figure 5 A 3D view of a single conductive busbar;

[0012] Figure 6 for Figure 5 A floor plan;

[0013] Figure 7 This is a 3D diagram of the connecting rows.

[0014] The annotations in the attached figures are explained as follows:

[0015] 100 enclosure, 101 base plate;

[0016] 200 Cylindrical battery, 201 Terminal, 202 Casing, 202a Casing end face, 203 Annular insulating component;

[0017] 300 Conductive busbar, 301 Terminal post connection, 302 Housing connection, 303 Transition part, 3031 First transition part, 3032 Second transition part, a First step, b Second step, c Notch, d Fixing hole;

[0018] 400 Insulation board, 401 Empty area, 402 Connecting post. Detailed Implementation

[0019] This application provides a cylindrical battery pack and battery device. To enable those skilled in the art to better understand the technical solution of this application, the following detailed description is provided in conjunction with the accompanying drawings and specific embodiments.

[0020] like Figure 1 As shown, the battery device provided in this application includes a housing 100 and at least two sets of cylindrical battery packs located within the housing 100. The housing 100 includes a base plate 101. The cylindrical battery packs include cylindrical batteries 200.

[0021] In some embodiments, the axis of the cylindrical battery 200 is parallel to the base plate 101, as is the case in the illustrated embodiment.

[0022] In some embodiments, the axis of the cylindrical battery 200 is perpendicular to the base plate 101.

[0023] Specifically, Figure 1 The system comprises eight sets of cylindrical battery packs, arranged in four rows of two, with the four rows arranged sequentially along the first direction. Two sets of cylindrical battery packs within the same row are stacked in a direction perpendicular to the base plate 101. Each set of cylindrical battery packs includes multiple cylindrical cells 200, with the axial direction of each cylindrical cell 200 along the first direction, and the cylindrical cells 200 of each set arranged sequentially along the second direction. The first and second directions are perpendicular to each other and parallel to the base plate 101. In practice, the number of rows of cylindrical battery packs can be less than four or more than four. Each row of cylindrical battery packs can also have more than two layers.

[0024] like Figure 2 As shown, the cylindrical battery pack also includes a conductive bus 300. The conductive bus 300 includes a terminal connection portion 301 and a housing connection portion 302.

[0025] like Figure 4 As shown, the cylindrical battery 200 includes a housing 202 and terminals 201. The terminals 201 are disposed on the end face 202a of the housing 202. The terminals 201 and the housing 202 are insulated from each other by an annular insulating member 203 surrounding the outer periphery of the terminals 201. The wall thickness of the housing 202 is less than the thickness of the terminals 201 in the axial direction of the cylindrical battery. The casing 202 and the terminal 201 serve as the positive output terminal and negative output terminal of the cylindrical battery 200, respectively. For example, when the casing 202 is made of steel, it can be used as the negative output terminal and the terminal 201 as the positive output terminal. When the casing 202 is made of aluminum, such as aluminum alloy or pure aluminum, the terminal 201 can be used as the negative output terminal and the casing 202 as the positive output terminal. In this case, the positive tab of the battery cell inside the casing 202 is electrically connected to the casing 202, and the negative tab of the battery cell is electrically connected to the terminal 201.

[0026] like Figure 3 As shown, the terminal connection portion 301 of the same conductive bus 300 is electrically connected to the side of the terminal 201 of a cylindrical battery 200 away from the housing 202, and the housing connection portion 302 is electrically connected to the housing 202 of another adjacent cylindrical battery 200.

[0027] A is equal to the thickness of the pole connecting part 301 divided by the thickness of the shell connecting part 302. A is in the range of 0.5≤A≤0.9, and A can be equal to 0.5, 0.6, 0.7, 0.8, or 0.9, for example.

[0028] If A is too large, the thickness of the shell connecting part 302 is small and the thickness of the pole connecting part 301 is large, which results in weak connection between the shell connecting part 302 and the shell 202 and strong connection between the pole connecting part 301 and the pole 201. The connection between the shell connecting part 302 and the shell 202 becomes a weak point and is prone to failure.

[0029] If A is too small, the thickness of the pole connecting part 301 is small and the thickness of the shell connecting part 302 is large, which results in weak connection between the pole connecting part 301 and the pole 201 and strong connection between the shell connecting part 302 and the shell 202. The connection between the pole connecting part 301 and the pole 201 becomes a weak point and is prone to failure. In addition, the small thickness of the pole connecting part 301 results in poor overcurrent capacity of the pole side. Moreover, because the thickness of the shell 202 in the axial direction of the cylindrical battery is smaller than the thickness of the pole 201, the large thickness of the shell connecting part 302 results in deformation of the shell 202 when the shell connecting part 302 is connected to the shell 202.

[0030] The cylindrical battery described above controls the ratio A of the thickness of the pole connecting part 301 to the thickness of the shell connecting part 302 in the range of 0.5-0.9, which balances the connection strength between the pole 201 and the conductive bar 300 and the connection strength between the shell 202 and the conductive bar 300, guarantees the overcurrent capacity of the pole side, and avoids deformation of the shell 202 during connection of the shell connecting part 302 to the shell 202.

[0031] In some embodiments, the pole 201 and the conductive bar 300 are made of different materials, the shell 202 and the conductive bar 300 are made of the same material, the melting point of the material of the pole 201 is greater than the melting point of the material of the conductive bar 300, the pole 201 is welded to the pole connecting part 301, and the shell 202 is welded to the shell connecting part 302. For example, the material of the pole 201 includes copper, and specifically can be pure copper or a copper alloy. Copper has good electrical conductivity, which guarantees the overcurrent capacity of the pole side. The material of the conductive bar 300 and the shell 202 includes aluminum, and specifically can be pure aluminum or an aluminum alloy.

[0032] When the pole 201 and the conductive bar 300 are made of different materials, and the melting point of the material of the pole 201 is greater than the melting point of the material of the conductive bar 300, the pole 201 is not easy to melt when the pole 201 and the pole connecting part 301 of the conductive bar 300 are welded, which affects the welding effect of the pole 201 and the pole connecting part 301, and causes the connection strength of the pole 201 and the pole connecting part 301 to be weak, so that the connection strength of the pole 201 and the shell 202 with the conductive bar 300 is not balanced. In this case, the thickness of the pole connecting part 301 can be further reduced to improve the welding effect of the pole 201 and the pole connecting part 301, so as to ensure that the connection strength of the pole 201 and the shell 202 with the conductive bar 300 is balanced. Therefore, in this case, the ratio A of the thickness of the pole connecting part 301 to the thickness of the shell connecting part 302 can be further reduced, so the range of the ratio A can be further limited to 0.5≤A≤0.8.

[0033] In some embodiments, the ratio of the thickness of the pole connecting part 301 to the thickness of the pole 201 in the axial direction of the cylindrical battery is defined as B, that is, B is equal to the thickness of the pole connecting part 301 divided by the thickness of the pole 201 in the axial direction of the cylindrical battery. The range of B is 0.25≤B≤0.6, and for example, B can be equal to 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, or 0.6. If B is too large, it will be difficult for heat to be transferred to the pole 201 during welding, which will result in poor welding effect. If B is too small, the welding penetration will be small, which will result in poor welding effect. Controlling B within the range of 0.25-0.6 can ensure the welding effect of the pole 201 and the pole connecting part 301, thereby ensuring the connection strength of the pole 201 and the pole connecting part 301.

[0034] In some embodiments, the ratio of the thickness of the shell connecting part 302 to the wall thickness of the shell 202 is defined as C, that is, C is equal to the thickness of the shell connecting part 302 divided by the wall thickness of the shell 202. The range of C is 0.4≤C≤1.5, and for example, C can be equal to 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, or 1.5. If C is too large, it will be difficult for heat to be transferred to the shell 202 during welding, which will result in poor welding effect. If C is too small, the welding penetration will be small, which will result in poor welding effect. Controlling C within the range of 0.4-1.5 can ensure the welding effect of the shell 202 and the shell connecting part 302, thereby ensuring the connection strength of the shell 202 and the shell connecting part 302.

[0035] In some embodiments, as shown in FIG. 6, the shell connecting part 302 has an arc-shaped notch c, and as shown in FIG. 7, the shell connecting part 302 has a straight notch d. Figure 5 Figure 3 ​As shown, the arc-shaped notch c is arranged around the outer periphery of the pole column 201. In this way, the shell connecting portion 302 can avoid the pole column 201 and can have a larger contact area with the shell end face 202a, so that the welding area between the shell end face 202a and the shell connecting portion 302 is sufficient, thereby ensuring the welding strength.

[0036] In some embodiments, the pole column 301 is a cylindrical structure, as shown in FIG. 2A. Figure 5 As shown, the pole column connecting portion 301 has a circular region which is shaped according to the circular end face of the pole column 201, and the diameter of the circular region is smaller than the diameter of the circular end face of the pole column 201, so as to avoid damaging the edge of the circular end face of the pole column 201 during welding.

[0037] In some embodiments, as shown in FIG. 2A, Figure 5 As shown, the conductive row 300 includes a transition portion 303. In the arrangement direction of the cylindrical battery row (i.e. in the second direction in the figure), the transition portion 303 is located between the pole column connecting portion 301 and the shell connecting portion 302, and the transition portion 303 connects the pole column connecting portion 301 and the shell connecting portion 302 together. In this way, during the vibration of the battery, the relative position of the pole column connecting portion 301 and the shell connecting portion 302 is relatively stable, so that the connection failure of the conductive row 300 and the cylindrical battery 200 is less likely to occur.

[0038] In some embodiments, as shown in FIG. 2A, Figure 5 As shown, the transition portion 303 has a first transition portion 3031 and a second transition portion 3032, the first transition portion 3031 is connected to the pole column connecting portion 301, and the second transition portion 3032 is located between the first transition portion 3031 and the shell connecting portion 302. In the thickness direction of the conductive row 300 (also the axial direction of the cylindrical battery 200), the second transition portion 3032 is farther away from the cylindrical battery 200 relative to the shell connecting portion 302, thereby forming a first bending portion a between the second transition portion 3032 and the shell connecting portion 302, and the first transition portion 3031 is farther away from the cylindrical battery 200 relative to the second transition portion 3032, thereby forming a second bending portion b between the second transition portion 3032 and the first transition portion 3031. In this way, the conductive row 300 has a three-dimensional structure with two bends, which can play a role in shock absorption and is more conducive to avoiding the connection failure of the cylindrical battery 200 and the conductive row 300.

[0039] In some embodiments, as shown in FIG. 2A, Figure 6As shown, in the direction perpendicular to the axial direction of the cylindrical battery 200 and perpendicular to the arrangement direction of the cylindrical batteries 200 of the cylindrical battery group (i.e. in the third direction in the figure), the width of the shell connecting portion 302 is greater than the width of the pole connecting portion 301. In this way, the welding area of the shell connecting portion 302 and the shell 202 can be increased, so as to more facilitate the improvement of the connection strength of the shell connecting portion 302 and the shell 202, and more facilitate the balance of the connection strength of the shell 202 and the shell connecting portion 302 and the connection strength of the pole 201 and the pole connecting portion 301.

[0040] In some embodiments, as shown in Figure 6 As shown, in the direction perpendicular to the axial direction of the cylindrical battery 200 and perpendicular to the arrangement direction of the cylindrical batteries 200 of the cylindrical battery group (i.e. in the third direction in the figure), the width of the second transition portion 3032 is greater than the width of the pole connecting portion 301, and the width of the first transition portion 3031 gradually decreases from the second transition portion 3032 to the pole connecting portion 301. In this way, the second transition portion 3032 requires less material, and is more conducive to saving the cost of the conductive row 300.

[0041] It should be noted that when the axial direction of the cylindrical battery 200 is perpendicular to the bottom plate 101, the third direction is parallel to the bottom plate 101, and when the axial direction of the cylindrical battery 200 is parallel to the bottom plate 101, the third direction is perpendicular to the bottom plate 101.

[0042] In some embodiments, the conductive row 300 is an integrally formed structure.

[0043] In some embodiments, as shown in Figure 5 As shown, the thickness of the transition portion 303 of the conductive row 300 is consistent with the thickness of the shell connecting portion 302, and is greater than the thickness of the pole connecting portion 301 of the conductive row 300.

[0044] In some embodiments, as shown in Figure 2 As shown, the cylindrical battery group includes an insulating plate 400, and the insulating plate 400 is located at one end of the cylindrical battery 200 where the pole 201 is arranged, and as shown in Figure 5 As shown, the transition portion 303 is provided with a fixing hole d, and the transition portion 303 is fixed to the insulating plate 400 through the fixing hole d.

[0045] Specifically, in the illustrated embodiment, as shown in Figure 2 As shown, the transition portions 303 of all the conductive rows 300 of the two groups of cylindrical battery groups stacked above and below are respectively fixed to the same insulating plate 400 through the respective fixing holes d. As shown in Figure 7As shown, the insulation plate 400 is provided with two rows of empty areas 401 and four rows of connecting columns 402. The upper row of empty areas 401 is used to accommodate the shell connecting portion 302 of the conductive row 300 of the upper layer of cylindrical battery group and the pole column 201 of the cylindrical battery 200, the lower row of empty areas 401 is used to accommodate the shell connecting portion 302 of the conductive row 300 of the lower layer of cylindrical battery group and the pole column 201 of the cylindrical battery 200, the upper two rows of connecting columns 402 are used to pass through the fixing holes d of each conductive row 300 of the upper layer of cylindrical battery group, and the lower two rows of connecting columns 402 are used to pass through the fixing holes d of each conductive row 300 of the lower layer of cylindrical battery group.

[0046] The above describes the principles and implementation manners of the present application by using specific examples. The above description of the examples is only used to help understand the method of the present application and its core idea. It should be noted that, for those skilled in the art, without departing from the principles of the present application, the present application can be improved and modified in several ways, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A cylindrical battery pack, characterized by, The cylindrical battery pack comprises cylindrical batteries (200) and a conductive row (300), the cylindrical batteries (200) comprise a shell (202) and a pole (201), the pole (201) is arranged on the shell end face (202a) of the shell (202), the wall thickness of the shell (202) is smaller than the thickness of the pole (201) in the axial direction of the cylindrical battery, the conductive row (300) comprises a pole connecting part (301) electrically connected to the side of the pole (201) away from the shell (202) and a shell connecting part (302) electrically connected to the shell (202), the ratio of the thickness of the pole connecting part (301) to the thickness of the shell connecting part (302) is A, and the range of A is: 0.5≤A≤0.

9.

2. The cylindrical battery pack according to claim 1, characterized by, The pole (201) and the conductive row (300) are made of different materials, the shell (202) and the conductive row (300) are made of the same material, the pole (201) is welded with the pole connecting part (301), the shell (202) is welded with the shell connecting part (302), the melting point of the material of the pole (201) is greater than the melting point of the material of the conductive row (300), and the range of A is: 0.5≤A≤0.

8.

3. The cylindrical battery pack according to claim 1, characterized by, The material of the pole (201) comprises copper, and the materials of the conductive row (300) and the shell (202) comprise aluminum.

4. The cylindrical battery pack according to claim 1, characterized by, The ratio of the thickness of the pole connecting part (301) to the thickness of the pole (201) in the axial direction of the cylindrical battery is B, and the range of B is: 0.25≤B≤0.6; and / or, The ratio of the thickness of the shell connecting part (302) to the wall thickness of the shell (202) is C, and the range of C is: 0.4≤C≤1.

5.

5. The cylindrical battery pack according to claim 1, wherein The shell connecting part (302) has an arc-shaped notch (c) surrounding the outer periphery of the pole (201).

6. The cylindrical battery pack according to claim 1, wherein The pole (201) is in a cylindrical structure, and the pole connecting part (301) has a circular area which is shaped according to the circular end face of the pole (201).

7. The cylindrical battery pack according to claim 1, wherein In the direction perpendicular to the axial direction of the cylindrical battery and perpendicular to the arrangement direction of the cylindrical batteries of the cylindrical battery pack, the width of the shell connecting part (302) is greater than the width of the pole connecting part (301).

8. The cylindrical battery pack of claim 1, wherein, The conductive row (300) comprises a transition part (303), which is located between the pole connecting part (301) and the shell connecting part (302) in the arrangement direction of the cylindrical batteries of the cylindrical battery pack, and connects the pole connecting part (301) and the shell connecting part (302) together.

9. The cylindrical battery pack according to claim 8, characterized by, The transition part (303) has a first transition part (3031) connected with the pole post connecting part (301) and a second transition part (3032) between the first transition part (3031) and the shell connecting part (302), a first bending part (a) is formed between the second transition part (3032) and the shell connecting part (302), and a second bending part (b) is formed between the second transition part (3032) and the first transition part (3031).

10. The cylindrical battery pack according to claim 9, characterized by In a direction perpendicular to the axial direction of the cylindrical battery and perpendicular to the arrangement direction of the cylindrical batteries of the cylindrical battery pack, the width of the second transition part (3032) is greater than the width of the pole post connecting part (301), and the width of the first transition part (3031) gradually decreases from the second transition part (3032) to the pole post connecting part (301).

11. The cylindrical battery pack of claim 8, wherein, The transition part (303) is provided with a fixing hole (d), the cylindrical battery pack includes an insulating plate (400), the insulating plate (400) is located at one end of the cylindrical battery (200) provided with the pole post (201), and the transition part (303) is fixed to the insulating plate (400) through the fixing hole (d).

12. The cylindrical battery pack according to any one of claims 1 to 11, characterized by, The material of the shell (202) includes aluminum, the cylindrical battery includes a cell, the cell includes a positive electrode lug and a negative electrode lug, the positive electrode lug is electrically connected with the shell (202), and the negative electrode lug is electrically connected with the pole post (201).

13. A battery device characterized by comprising: The battery device includes a box body (100) and at least one group of cylindrical battery packs according to any one of claims 1-12 located in the box body (100).

14. The battery device of claim 13, wherein, The box body (100) includes a bottom plate (101), and the axial direction of the cylindrical battery (200) of the cylindrical battery pack is parallel to or perpendicular to the bottom plate (101).

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