Cylindrical battery and power device

Abstract

The utility model relates to the technical field of batteries, and discloses a cylindrical battery and a power plant, the cylindrical battery comprises a shell and a cathode cover plate, and the shell is provided with an open end; the negative electrode cover plate is arranged at the open end of the shell and comprises a cover plate body and a boss which is arranged on the periphery of the cover plate body and protrudes towards the side away from the shell, the boss comprises a connecting face and a first guide face, and the connecting face covers the outer end face of the open end of the shell and is fixedly connected with the shell. At least part of the first guide face abuts against the inner wall of the shell. According to the utility model, the connecting surface of the boss is matched with the outer end surface of the open end of the shell in an abutting manner, at least part of the first guide surface of the boss is abutted against the inner wall of the shell, and the negative electrode cover plate is fixedly connected with the shell through the boss, and plays a bidirectional limiting role in the axial direction and the radial direction at the same time, so that the assembling and positioning precision of the negative electrode cover plate is improved, and the service life of the negative electrode cover plate is prolonged. Therefore, welding difficulty is reduced, and product reliability is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a cylindrical battery and a power device. Background Art

[0002] Cylindrical batteries are batteries with high capacity, long cycle life and wide operating temperature range, providing energy convenience for people's production and life. With the development of the battery industry, the requirements for battery performance are also increasing, including the assembly between the various structural parts of the battery.

[0003] The existing cylindrical battery includes a shell and a negative electrode cover plate arranged at one end of the shell, and the negative electrode cover plate and the shell are welded. However, the current negative electrode cover plates are all plates with flat surfaces. Due to the processing errors of the shell and the negative electrode cover plate, the positioning accuracy between the negative electrode cover plate and the shell is low, and position deviation is easy to occur during the welding process, which makes welding difficult and the product reliability is poor. Utility Model Content

[0004] In view of this, the utility model provides a cylindrical battery and a power device to solve the problems of low positioning accuracy and great welding difficulty between the negative electrode cover plate and the shell.

[0005] In the first aspect, the utility model provides a cylindrical battery, comprising a shell and a negative electrode cover plate, the shell having an open end; the negative electrode cover plate is arranged at the open end of the shell, the negative electrode cover plate comprises a cover plate body and a boss arranged at the outer periphery of the cover plate body and protruding toward a side away from the shell, the boss comprises a connecting surface and a first guide surface, the connecting surface cover is arranged on the outer end surface of the open end of the shell and is fixedly connected to the shell, the first guide surface at least partially abuts against the inner wall of the shell or the first guide surface and the inner wall of the shell are not abutted.

[0006] Beneficial effect: The connection surface of the boss covers the outer end surface of the open end of the shell, and the negative electrode cover plate and the shell can be fixedly connected by connecting between the connection surface and the outer end surface of the open end of the shell. At the same time, the connection surface and the outer end surface of the open end of the shell are abutted and matched, which plays a role in positioning the shell along the axial direction during the assembly of the negative electrode cover plate and the shell. The boss is provided with a first guide surface, and the first guide surface at least partially abuts against the inner wall of the shell. In this way, the first guide surface and the internal abutment portion of the shell play a role in positioning the shell along the radial direction during the assembly of the negative electrode cover plate and the shell. By providing the boss, the negative electrode cover plate not only realizes a fixed connection with the shell, but also plays a bidirectional limiting role in the axial and radial directions, thereby improving the assembly positioning accuracy of the negative electrode cover plate, thereby reducing the difficulty of welding and improving the reliability of the product.

[0007] In an optional embodiment, there is a first angle between the connecting surface and the first guide surface, and the first angle is in a range of 90° to 160°.

[0008] Beneficial effect: This arrangement can ensure the effective contact area between the first guide surface and the inner wall of the shell, thereby ensuring the positioning effect.

[0009] In an optional embodiment, the ratio of the width of the connecting surface to the height of the first guide surface is in the range of 0.2 to 2.

[0010] Beneficial effect: The ratio of the width of the connecting surface to the height of the first guide surface is controlled within the range of 0.2 to 2, which not only ensures the space utilization of the product but also makes it easier to process and manufacture.

[0011] In an optional embodiment, the cover plate body is provided with a liquid injection hole, the liquid injection hole is communicated with the inner cavity of the shell, and the diameter of the liquid injection hole is in the range of 2.5 mm to 4 mm.

[0012] Beneficial effects: Controlling the diameter of the injection hole within a range greater than 2.5 mm can solve the problem of difficult injection and make injection smoother; controlling the diameter of the injection hole within a range less than 4 mm can avoid gas generation during the injection process and ensure battery performance.

[0013] In an optional embodiment, the cover plate body is provided with a groove recessed toward the inner cavity of the shell, and the injection hole is provided at the bottom of the groove; the cylindrical battery also includes a sealing cover plate, which is provided in the groove, and the sealing cover plate includes a first sealing surface, which abuts against the bottom of the groove for sealing the injection hole.

[0014] Beneficial effect: By setting a groove on the cover body, the sealing cover can be assembled in the groove, so as not to occupy the axial space of the entire battery. After the injection is completed, the sealing cover is assembled, and the first sealing surface of the sealing cover abuts against the bottom of the groove to block the injection hole and seal the electrolyte in the inner cavity of the shell.

[0015] In an optional embodiment, a second guide surface is connected between the groove and the cover plate body, a second angle exists between the groove bottom surface of the groove and the second guide surface, and the second angle is in the range of 15° to 60°. The sealing cover plate also includes a second sealing surface connected to the first sealing surface, and the second sealing surface is in sealing contact with the second guide surface.

[0016] Beneficial effect: By setting the second guide surface between the groove and the cover body, that is, the side wall of the groove, and the second sealing surface of the sealing cover plate abutting and sealing, the leakage path is extended and the sealing effect is improved. The second angle between the groove bottom surface and the second guide surface is within the range of 15° to 60°, which is conducive to processing, manufacturing and assembly.

[0017] In an optional embodiment, the cover body is provided with an explosion-proof valve, the projection area of ​​the explosion-proof valve along the axial direction of the shell is S1, the projection area of ​​the negative electrode cover along its axial direction is S2, and the ratio of S1 to S2 is in the range of 0.5 to 0.85.

[0018] Beneficial effects: This arrangement ensures that the explosion-proof valve has sufficient effective pressure relief area, ensures the stability of the opening pressure, and ensures the safety of the battery cell; at the same time, the negative electrode cover has sufficient strength, is easy to process and manufacture, and ensures product reliability.

[0019] In an optional embodiment, the total height of the negative electrode cover plate along the axial direction is in the range of 0.8 mm to 2 mm.

[0020] Beneficial effect: The total axial height of the negative electrode cover is controlled within the range of 0.8 mm to 2 mm, which can not only ensure the strength of the negative electrode cover, facilitate processing and assembly, but also achieve weight reduction and cost reduction.

[0021] In an optional embodiment, the cover plate body includes a recessed portion and / or a raised portion, the recessed portion and the raised portion are both annular, and the recessed portion and the raised portion are radially staggered around the center of the cover plate body.

[0022] Beneficial effect: With this arrangement, the cover plate body has a corrugated plate structure with concave and convex structures arranged alternately in the radial direction, ensuring that the cover plate has sufficient strength and toughness.

[0023] In a second aspect, the utility model also provides a power device, comprising a cylindrical battery according to any one of the above technical solutions.

[0024] Because the power device includes cylindrical batteries, it has the same effect as the cylindrical batteries and will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 This is a front view of a cylindrical battery according to an embodiment of the utility model;

[0027] Figure 2 for Figure 1 A cross-sectional view of the cylindrical battery shown along the axial direction;

[0028] Figure 3 for Figure 2The schematic diagram of the partial enlargement of the cylindrical battery at the negative electrode cover;

[0029] Figure 4 for Figure 3 A schematic diagram of the local enlarged structure at B in the middle;

[0030] Figure 5 for Figure 2 A three-dimensional diagram of the middle negative electrode cover;

[0031] Figure 6 for Figure 4 A bottom view of the negative electrode cover shown;

[0032] Figure 7 for Figure 6 Sectional view along AA;

[0033] Figure 8 It is a longitudinal cross-sectional view of the sealing cover plate;

[0034] Fig. 9 It is a schematic diagram of the assembly of the negative electrode cover plate and the sealing cover plate.

[0035] Description of reference numerals:

[0036] 1. Shell; 2. Negative electrode cover plate; 201. Cover plate body; 202. Boss; 2021. Connecting surface; 2022. First guide surface; 203. Groove; 2031. Second guide surface; 3. Liquid injection hole; 4. Sealing cover plate; 401. First sealing surface; 402. Second sealing surface; 5. Explosion-proof valve; 6. Pole group. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0038] Combine the following Figures 1 to 9 , describing an embodiment of the utility model.

[0039] According to an embodiment of the utility model, on the one hand, a cylindrical battery is provided, including a shell 1 and a negative electrode cover plate 2, the shell 1 having an open end; the negative electrode cover plate 2 is arranged at the open end of the shell 1, the negative electrode cover plate 2 includes a cover plate body 201 and a boss 202 arranged on the outer periphery of the cover plate body 201 and protruding toward the side away from the shell 1, the boss 202 includes a connecting surface 2021 and a first guide surface 2022, the connecting surface 2021 is covered on the outer end surface of the open end of the shell 1 and is fixedly connected to the shell 1, the first guide surface 2022 at least partially abuts against the inner wall of the shell 1 or the first guide surface 2022 does not abut against the inner wall of the shell 1.

[0040] The housing 1 has a cavity, and the housing 1 and the negative electrode cover plate 2 encapsulate the electrode group 6 in the cavity. The open end of the housing 1 is connected to the inner insert for assembling the electrode group 6. The connection surface 2021 of the boss 202 covers the outer end surface of the open end of the housing 1, and the negative electrode cover plate 2 and the housing 1 can be fixedly connected by connecting the connection surface 2021 and the outer end surface of the open end of the housing 1. At the same time, the connection surface 2021 and the outer end surface of the open end of the housing 1 are abutted and matched, which plays a positioning role along the axial direction of the housing 1 during the assembly process of the negative electrode cover plate 2 and the housing 1. By setting the first guide surface 2022 on the boss 202, when the negative electrode cover plate 2 and the shell 1 are assembled, it can play a guiding role, which is convenient for assembly. The first guide surface 2022 may not abut against the inner wall of the shell 1, that is, there is a gap between the first guide surface 2022 and the inner wall of the shell 1, and the first guide surface 2022 plays the role of assembly guide; of course, it is also possible that the first guide surface 2022 at least partially abuts against the inner wall of the shell 1, so that the first guide surface 2022 and the inner abutting part of the shell 1 play a radial positioning role of the shell 1 during the assembly process of the negative electrode cover plate 2 and the shell 1. By setting the boss 202, the negative electrode cover plate 2 plays a two-way limiting role in the axial and radial directions while achieving a fixed connection with the shell 1, thereby improving the assembly positioning accuracy of the negative electrode cover plate 2, thereby reducing the welding difficulty and improving the reliability of the product.

[0041] In one embodiment, the connection surface 2021 is welded to the outer end surface of the housing 1. Specifically, laser welding is used between the connection surface 2021 and the outer end surface of the housing 1. Figure 4 As shown, Figure 4 The arrow shown in LB indicates the welding direction of the laser beam. The joint between the connecting surface 2021 of the negative electrode cover plate 2 and the outer end surface of the open end of the shell 1 is the welding part. A smaller laser energy can meet the welding requirements, and the welding performance can be directly observed, which is convenient for detection.

[0042] In one embodiment, there is a first angle between the connecting surface 2021 and the first guiding surface 2022 , and the first angle is in a range of 90° to 160°.

[0043] The first angle between the connecting surface 2021 and the first guide surface 2022 is as follows: Figure 7 As shown in α in the figure, controlling the first angle α within the range of 90° to 160° can ensure the effective contact area between the first guide surface 2022 and the inner wall of the shell 1, thereby ensuring the positioning effect.

[0044] In one embodiment, the ratio of the width of the connecting surface 2021 to the height of the first guide surface 2022 is in the range of 0.2 to 2.

[0045] Specifically, the width of the connection surface 2021 is the extension length along the radial direction of the negative electrode cover plate 2, and the height of the first guide surface 2022 is the height protruding from the cover plate body 201. The ratio of the width of the connection surface 2021 to the height of the first guide surface 2022 is controlled within the range of 0.2 to 2, which not only ensures the space utilization of the product, but also makes it easier to process and manufacture; if the ratio of the width of the connection surface 2021 to the height of the first guide surface 2022 is less than 0.2, it will occupy the internal space of the housing 1, and the space utilization is relatively low; if the ratio of the width of the connection surface 2021 to the height of the first guide surface 2022 is greater than 2, it is difficult to process the cover plate.

[0046] In one embodiment, the cover body 201 is provided with a liquid injection hole 3, the liquid injection hole 3 is communicated with the inner cavity of the shell 1, and the diameter of the liquid injection hole 3 is in the range of 2.5 mm to 4 mm.

[0047] Controlling the diameter of the injection hole 3 within a range greater than 2.5 mm can solve the problem of difficult injection and make the injection smoother; controlling the diameter of the injection hole 3 within a range less than 4 mm can avoid gas generation during the injection process and ensure battery performance.

[0048] In one embodiment, the cover body 201 is provided with a groove 203 which is recessed toward the inner cavity of the shell 1, and the injection hole 3 is provided at the bottom of the groove 203; the cylindrical battery also includes a sealing cover plate 4, which is provided in the groove 203, and the sealing cover plate 4 includes a first sealing surface 401, and the first sealing surface 401 abuts against the bottom of the groove 203 for sealing the injection hole 3.

[0049] By providing the groove 203 on the cover body 201, the sealing cover 4 can be assembled in the groove 203, so as not to occupy the axial space of the entire battery. After the injection is completed, the sealing cover 4 is assembled, and the first sealing surface 401 of the sealing cover 4 abuts against the bottom of the groove 203, blocking the injection hole 3, and sealing the electrolyte in the inner cavity of the shell 1.

[0050] In one embodiment, a second guide surface 2031 is connected between the groove 203 and the cover body 201, and a second angle exists between the bottom surface of the groove 203 and the second guide surface 2031, such as Figure 7As shown in the middle angle β, the second angle β is in the range of 15° to 60°. The sealing cover plate 4 further includes a second sealing surface 402 connected to the first sealing surface 401 , and the second sealing surface 402 is in sealing contact with the second guide surface 2031 .

[0051] By providing the second guide surface 2031 between the groove 203 and the cover body 201, that is, the side wall of the groove 203, and the second sealing surface 402 of the sealing cover 4 to abut and seal, the leakage path is extended and the sealing effect is improved. The second angle between the groove bottom surface of the groove 203 and the second guide surface 2031 is within the range of 15° to 60°, which is conducive to processing, manufacturing and assembly.

[0052] In one embodiment, the cover body 201 is provided with an explosion-proof valve 5, the projection area of ​​the explosion-proof valve 5 along the axial direction of the shell 1 is S1, the projection area of ​​the negative electrode cover 2 along its axial direction is S2, and the ratio of S1 to S2 is in the range of 0.5 to 0.85.

[0053] By controlling the ratio of S1 to S2 within a range greater than 0.5, it can be ensured that the explosion-proof valve 5 has sufficient effective pressure relief area, ensure the stability of the opening pressure, and ensure the safety of the battery cell; by controlling the ratio of S1 to S2 within a range less than 0.85, the negative electrode cover plate 2 has sufficient strength, is easy to process and manufacture, and ensures product reliability.

[0054] In one embodiment, the explosion-proof valve 5 includes an explosion-proof notch on the cover body 201, and the notch has any shape, including V-shaped, U-shaped, trapezoidal, etc. The explosion-proof notch is weak in strength, and explodes to release pressure when the air pressure in the housing 1 reaches a set value.

[0055] In one embodiment, the total height of the negative electrode cover plate 2 along the axial direction is in the range of 0.8 mm to 2 mm.

[0056] The total axial height of the negative electrode cover plate 2 is controlled within the range of 0.8 mm to 2 mm, which can ensure the strength of the negative electrode cover plate 2, facilitate processing and assembly, and achieve weight reduction and cost reduction.

[0057] In one embodiment, the cover plate body 201 includes a groove portion and / or a protrusion portion, and the groove portion and the protrusion portion are both annular, and the groove portion and the protrusion portion are arranged around the center of the cover plate body 201 and staggered in the radial direction.

[0058] In this way, the cover plate body 201 has a corrugated plate structure with concave and convex structures arranged alternately in the radial direction, which ensures that the cover plate has sufficient strength and toughness.

[0059] Specifically, the housing 1 has an inner cavity for accommodating the electrode group 6 , and the negative electrode cover plate 2 and the housing 1 seal the electrode group 6 in the inner cavity of the housing 1 .

[0060] According to an embodiment of the present utility model, on the other hand, a power device is also provided, comprising a cylindrical battery according to any one of the above technical solutions.

[0061] Because the power device includes cylindrical batteries, it has the same effect as the cylindrical batteries and will not be described in detail here.

[0062] Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A cylindrical battery, characterized in that: include: a housing having an open end; A negative electrode cover plate is arranged at the open end of the shell, and the negative electrode cover plate includes a cover plate body and a boss arranged at the outer periphery of the cover plate body and protruding toward a side away from the shell, the boss includes a connecting surface and a first guide surface, the connecting surface cover is arranged on the outer end surface of the open end of the shell and is fixedly connected to the shell, the first guide surface at least partially abuts against the inner wall of the shell or the first guide surface does not abut against the inner wall of the shell.

2. The cylindrical battery according to claim 1, characterized in that: There is a first angle between the connecting surface and the first guide surface, and the first angle is in the range of 90° to 160°.

3. The cylindrical battery according to claim 1 or 2, characterized in that: A ratio of a width of the connecting surface to a height of the first guide surface is in a range of 0.2 to 2.

4. The cylindrical battery according to claim 1 or 2, characterized in that: The cover plate body is provided with a liquid injection hole, the liquid injection hole is communicated with the inner cavity of the shell, and the diameter of the liquid injection hole is in the range of 2.5 mm to 4 mm.

5. The cylindrical battery according to claim 4, characterized in that: The cover plate body is provided with a groove which is recessed toward the inner cavity of the shell, and the injection hole is provided at the bottom of the groove; the cylindrical battery also includes a sealing cover plate, which is provided in the groove, and the sealing cover plate includes a first sealing surface, which abuts against the bottom of the groove to seal the injection hole.

6. The cylindrical battery according to claim 5, characterized in that: A second guide surface is connected between the groove and the cover plate body, a second angle exists between the groove bottom surface of the groove and the second guide surface, and the second angle is in the range of 15° to 60°. The sealing cover plate also includes a second sealing surface connected to the first sealing surface, and the second sealing surface is in sealing contact with the second guide surface.

7. The cylindrical battery according to claim 1 or 2, characterized in that: The cover plate body is provided with an explosion-proof valve, the projection area of ​​the explosion-proof valve along the axial direction of the shell is S1, the projection area of ​​the negative electrode cover plate along its axial direction is S2, and the ratio of S1 to S2 is in the range of 0.5 to 0.

85.

8. The cylindrical battery according to claim 1 or 2, characterized in that: The total height of the negative electrode cover plate along the axial direction is in the range of 0.8 mm to 2 mm.

9. The cylindrical battery according to claim 1 or 2, characterized in that: The cover plate body comprises a recessed portion and / or a raised portion, wherein the recessed portion and the raised portion are both annular in shape, and the recessed portion and the raised portion are radially staggered around the center of the cover plate body.

10. A power device, characterized in that: A cylindrical battery comprising any one of claims 1 to 9.

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