Pole sealed cover plate assembly and battery cell

Abstract

The utility model relates to a pole sealing type cover plate assembly which comprises a top cover plate, a top cover plate and a bottom cover plate, wherein the top cover plate is hermetically welded at the end part of a shell of a battery cell; the rivet pole penetrates through the top cover plate, one end, provided with a flat head, of the rivet pole is connected with a switching piece, the circumferential direction of the rivet pole is insulated and separated from the top cover plate through a sealing piece, and a lower insulating bracket is arranged between the switching piece and the top cover plate; the end, connected with the flat head, of the rivet pole is provided with a first conical part, the sealing piece is provided with a second conical part corresponding to the first conical part, and the inner diameter of the second conical part is smaller than the outer diameter of the first conical part. According to the utility model, the sealing element is not only subjected to axial pressure, but also subjected to extrusion of the rivet pole in the radial direction, so that the sealing performance is strong, and the service life of the battery cell is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium batteries, in particular to a pole-sealed cover plate assembly and a battery core. Background Art

[0002] The structural parts of lithium battery cells include cover assembly and outer shell. The cover assembly of lithium battery is an important part of battery packaging. Its main function is to protect the battery pole group, prevent the leakage of chemical substances inside the battery, and avoid the influence of the external environment on the battery.

[0003] However, in the prior art, the seal and the pole have fixed diameters. In order to fit the seal into the top cover plate and the pole into the seal, there is a certain gap between the components, which results in an unsatisfactory sealing effect of the cover plate assembly and causes the battery seal to fail, thereby causing electrolyte leakage, battery short circuit or capacity decay, and posing a safety hazard to the battery. Utility Model Content

[0004] Therefore, the technical problem to be solved by the utility model is to overcome the defect of poor sealing effect between the seal and the pole in the prior art, and to provide a cover plate assembly and a battery cell that change the structure of the pole and the seal.

[0005] In order to solve the above technical problems, the utility model provides a pole sealed cover assembly, comprising:

[0006] A top cover plate, the top cover plate being sealed and welded to the end of the outer shell of the battery cell;

[0007] A rivet pole, the rivet pole passes through the top cover plate, one end of the rivet pole is provided with a flat head connected to the adapter plate, the rivet pole is circumferentially insulated and separated from the top cover plate by a seal, and a lower insulating bracket is provided between the adapter plate and the top cover plate;

[0008] One end of the rivet pole connected to the flat head is provided as a first conical portion, and the seal is provided with a second conical portion corresponding to the first conical portion, wherein the inner diameter of the second conical portion is smaller than the outer diameter of the first conical portion.

[0009] In one embodiment of the utility model, a mounting hole for accommodating the end of the rivet pole is provided on the adapter plate, and the mounting hole is divided into a first mounting hole and a second mounting hole from top to bottom along the axial direction, and the first mounting hole and the second mounting hole have different sizes.

[0010] In one embodiment of the present invention, the size of the second mounting hole matches the size of the flat head, and the size of the first mounting hole is smaller than the size of the second mounting hole.

[0011] In one embodiment of the present invention, the thickness of the upper end of the second tapered portion is smaller than the thickness of the lower end.

[0012] In an embodiment of the present invention, two ends of the sealing member are provided with a first step and a second step extending outward along the inner circumference.

[0013] In an embodiment of the utility model, the other end of the rivet pole is connected to an upper pressing block, and the upper pressing block is separated from the top cover plate by an upper insulating bracket.

[0014] In one embodiment of the present invention, the sealing element is formed by injection molding.

[0015] The utility model also provides a battery core, comprising:

[0016] A pole group, wherein the positive pole ear and the negative pole ear of the pole group are located on the same side;

[0017] a housing having an open end;

[0018] The cover plate assembly comprises a positive electrode mounting hole and a negative electrode mounting hole respectively disposed at both ends of the top cover plate, a safety valve disposed in the middle of the top cover plate, and a liquid injection hole disposed between the safety valve and the negative electrode mounting hole.

[0019] In one embodiment of the utility model, repair holes are provided on the top cover plate at positions corresponding to the supporting parts at both ends of the lower insulating bracket.

[0020] In one embodiment of the utility model, the positive electrode mounting hole and the negative electrode mounting hole are respectively provided with two, and the rivet poles are correspondingly provided with two positive poles and two negative poles, the positive poles pass through the positive pole mounting holes to connect the positive pole adapter plate, and the negative poles pass through the negative pole mounting holes to connect the negative pole adapter plate, and the two sealing members respectively isolate the positive poles from the top cover plate and the negative poles from the top cover plate.

[0021] The above technical solution of the utility model has the following advantages compared with the prior art:

[0022] In the utility model, by setting the lower part of the pole to be conical, the seal is not only subjected to axial pressure, but also subjected to radial squeezing force of the pole on the seal, thereby improving the sealing performance between the seal and the pole;

[0023] The utility model arranges the mounting hole on the adapter plate into two sections, thus changing the infiltration path of the electrolyte and further improving the sealing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to make the content of the utility model easier to understand, the utility model is further described in detail according to the specific embodiments of the utility model in combination with the accompanying drawings, wherein:

[0025] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0026] Figure 2 It is a cross-sectional view of the utility model;

[0027] Figure 3 It is an exploded view of the utility model;

[0028] Figure 4 This utility model Figure 2 A magnified view of the structure of the middle A area;

[0029] Figure 5 It is a cross-sectional view of the sealing element of the utility model;

[0030] Figure 6 It is a schematic diagram of the battery cell of the utility model;

[0031] Figure 7 This utility model Figure 2 Enlarged view of the structure of area B.

[0032] Description of the Figures in the Specification:

[0033] 10. Cover plate assembly; 11. Top cover plate; 111. Positive electrode mounting hole; 112. Negative electrode mounting hole; 12. Riveted pole; 121. Flat head; 122. First conical portion; 123. First step; 124. Second step; 13. Adapter; 131. First mounting hole; 132. Second mounting hole; 14. Seal; 141. Second conical portion; 15. Lower insulating bracket; 16. Upper pressing block; 17. Upper insulating bracket; 18. Safety valve; 19. Repair hole;

[0034] 20. Pole group;

[0035] 30. Shell. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only some embodiments of the utility model, not all embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0037] Reference Figure 1-3 As shown, Figure 1 The overall structure of the cover plate assembly 10 of the present invention is as follows: Figure 2is a cross-sectional view of the cover plate assembly 10 of the present invention, Figure 3 This is an exploded view of the cover plate of the present invention.

[0038] Specifically, the pole sealed cover plate assembly 10 of the utility model includes a top cover plate 11, which is sealed and welded to the end of the outer shell 30 of the battery cell to fix and seal the bare pole group 20 in the outer shell 30. It also includes a rivet pole 12, which is used to connect and conduct with the pole ear of the pole group 20 through the adapter 13 to ensure the conduction of the charging and discharging current of the battery cell, and can also fix the cover plate assembly 10. A flat head 121 is provided at one end of the rivet pole 12. When connecting, first fix the end with the flat head 121 to the adapter 13, install the seal 14 on the top cover plate 11, and then pass the rivet pole 12 through the lower insulating bracket 15, the seal 14 and the top cover plate 11. At this time, the rivet pole 12 is circumferentially insulated and separated from the top cover plate 11 by the seal 14, and the adapter 13 is insulated and separated from the top cover plate 11 by the lower insulating bracket 15, preventing electrical conduction between the positive electrode and the top cover plate 11, avoiding potential electrical short circuit or electric shock risks, and enhancing the safety of the battery cell.

[0039] In order to facilitate the installation of the seal 14 and the top cover plate 11, the rivet pole 12 and the seal 14, the outer diameter of the seal 14 is usually slightly smaller than the diameter of the pole installation hole on the top cover plate 11, and the outer diameter of the rivet pole 12 is usually slightly smaller than the inner diameter of the seal 14. However, in this case, even if the lower part of the seal 14 presses the adapter 13 and / or the flat head 121 after assembly, the sealing effect cannot be guaranteed. For this reason, refer to Figure 4 As shown, in this embodiment, one end of the rivet pole 12 connected to the flat head 121 is set as a first conical portion 122, and the seal 14 is provided with a second conical portion 141 corresponding to the first conical portion 122, and the inner diameter of the second conical portion 141 is smaller than the outer diameter of the first conical portion 122. In this case, after the rivet pole 12 passes through the lower insulating bracket 15, the seal 14 and the top cover plate 11, the rivet pole 12 is riveted, and the seal 14, the top cover plate and the lower insulating bracket 15 are subjected to the downward pressure generated by the riveting in the height direction, and the lower part of the rivet pole 12 is a conical structure, even if its outer diameter is larger than the inner diameter of the seal 14, it can ensure that the rivet pole 12 and the seal 14 are fully matched, and each component is pressed in the height direction. At the same time, in the vertical direction, since the inner diameter of the seal 14 is smaller than the outer diameter of the rivet pole 12, the seal 14 is squeezed by the rivet pole 12, causing the seal 14 to expand and squeeze radially, thereby improving the sealing performance between the rivet pole 12 and the seal 14, and improving the sealing performance between the seal 14 and the top cover plate 11.

[0040] Reference Figure 4As shown, in order to further improve the sealing effect of the pole, the adapter plate 13 is provided with a mounting hole for accommodating the end of the rivet pole 12, and the mounting hole is divided into a first mounting hole 131 and a second mounting hole 132 from top to bottom along the axial direction, and the sizes of the first mounting hole 131 and the second mounting hole 132 are different. Therefore, even if the weld between the rivet pole 12 and the adapter plate 13 is not enough to block the infiltration of the electrolyte, the electrolyte first enters from the joint between the second mounting hole 132 and the rivet pole 12 during the infiltration process. When reaching the top of the joint, due to the different sizes of the first mounting hole 131 and the second mounting hole 132, the electrolyte needs to turn two corners to enter the first mounting hole 131 and continue to seep out. At this time, the corner between the second mounting hole 132 and the first mounting hole 131 not only increases the resistance to the infiltration of the electrolyte, but also increases the length of the electrolyte infiltration path. The high sealing between the matching seal 14 and the rivet pole 12 greatly improves the sealing of the cover plate assembly 10. Therefore, the thickness of the adapter sheet 13 can be reduced, thereby reducing the weight of the cover plate assembly 10 and achieving a lightweight design of the battery cell.

[0041] Furthermore, in this embodiment, the size of the second mounting hole 132 matches the size of the flat head 121, and the size of the first mounting hole 131 is smaller than the size of the second mounting hole 132. The rivet pole 12 passes through the bottom of the adapter 13, and the weld is located at the bottom of the rivet pole 12 and the adapter 13, which is convenient for operation. In this way, the installation and fixation of the rivet pole 12 and the adapter 13 are extremely simple.

[0042] Reference Figure 5 As shown, since the seal 14 is subjected to the outward extrusion force of the rivet pole 12 in the radial direction, the seal 14 is more closely fitted to the rivet pole 12, and the seal 14 is deformed. In order to ensure the strength of the seal 14, the thickness of the upper end of the second conical portion 141 is set to be less than the thickness of the lower end in this embodiment. Therefore, even if the seal 14 is deformed, it can be ensured that the strength of the deformed part will not be lower than the strength of other positions. In order to ensure that the upper and lower ends of the seal 14 are also pressed against other components, the first step 142 and the second step 143 are respectively extended outward along the inner circumference at both ends of the seal 14 in this embodiment. When the rivet pole 12 is riveted and fixed, the seal 14 is subjected to axial pressure, the second step 143 presses the flat head 121 below, and the first step 142 presses the flange of the rivet pole 12 above, or other components. When the upper and lower ends and the inner circumference of the seal 14 are respectively pressed, the sealing around the rivet pole 12 is good, so the sealing of the cover plate assembly 10 is good. In this embodiment, the sealing member 14 is formed by injection molding, which is convenient for processing.

[0043] Reference Figure 4As shown, in order to facilitate the connection of the rivet pole 12 with the busbar and other structures in the module, the other end of the rivet pole 12 is connected to an upper pressing block 16, and the upper pressing block 16 is separated from the top cover plate 11 by an upper insulating bracket 17. The existence of the upper pressing block 16 increases the area where the rivet pole 12 can contact the busbar, ensuring the conduction of current.

[0044] The utility model also provides a battery cell, including a pole group 20, wherein the positive pole ear and the negative pole ear of the pole group 20 are located on the same side, which can reduce the volume of the battery cell and facilitate series and parallel use. A shell 30, wherein the end of the shell 30 is open, which is convenient for loading the pole group 20, so as to achieve fixation and sealing of the pole group 20. It also includes the above-mentioned cover plate assembly 10. In this embodiment, the two ends of the top cover plate 11 are respectively provided with a positive pole mounting hole 111 and a negative pole mounting hole 112, and a safety valve 18 is provided in the middle of the top cover plate 11, and a liquid injection hole is provided between the safety valve 18 and the negative pole mounting hole 112. The middle position is relatively stable and evenly stressed, which can reduce the risk of damage caused by external impact or vibration, and the middle position is easier to approach and operate, making it more convenient and quick for operators to perform maintenance, liquid injection or replacement of parts, etc., reducing the difficulty of operation and time cost.

[0045] Furthermore, the battery cell will consume the internal electrolyte and generate a certain amount of gas during use. However, since the battery cell is completely sealed, in order to replenish the battery cell, this embodiment provides a repair hole 19 on the top cover plate 11 at the position corresponding to the supporting parts at both ends of the lower insulating bracket 15. The thickness of the top cover plate 11 at the repair hole 19 is less than the thickness of the top cover plate 11 in other areas, so the repair hole 19 is easy to open. Since only the battery cell is replenished, the diameter of the repair hole 19 is small, and steel balls can be used for secondary sealing after the repair hole 19 is opened, thereby increasing the service life of the battery cell.

[0046] In order to further solve the problems of insufficient current conduction capacity and uneven current density distribution of the electrode in large-capacity battery cells, in the present embodiment, two positive electrode mounting holes 111 and two negative electrode mounting holes 112 are respectively provided, and the contact areas between the adapter plate 13 and the electrode ear, the rivet pole 12 and the adapter plate 13, and the bus and the rivet pole 12 are large, which increases the electrical performance of the battery cell, is suitable for large current charging and discharging, and prolongs the service life of the battery cell.

[0047] To this end, the rivet pole 12 is correspondingly configured as two positive poles and two negative poles, the positive pole passes through the positive mounting hole 111 to connect the positive adapter plate 13, and the negative pole passes through the negative mounting hole 112 to connect the negative adapter plate 13. The two poles are locked to each other, and can also effectively prevent the poles from rotating. The two seals 14 respectively isolate the positive pole from the top cover plate 11 and the negative pole from the top cover plate 11. One seal 14 corresponds to two rivet poles 12, fewer assembled structural components, and improved production and assembly efficiency.

[0048] Obviously, the above embodiments are merely examples for the purpose of clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention of the utility model.

Claims

1. A pole sealed cover plate assembly, characterized in that: include: A top cover plate, the top cover plate being sealed and welded to the end of the outer shell of the battery cell; A rivet pole, the rivet pole passes through the top cover plate, one end of the rivet pole is provided with a flat head connected to the adapter plate, the rivet pole is circumferentially insulated and separated from the top cover plate by a seal, and a lower insulating bracket is provided between the adapter plate and the top cover plate; One end of the rivet pole connected to the flat head is provided as a first conical portion, and the seal is provided with a second conical portion corresponding to the first conical portion, wherein the inner diameter of the second conical portion is smaller than the outer diameter of the first conical portion.

2. A pole sealed cover plate assembly according to claim 1, characterized in that: The adapter plate is provided with a mounting hole for accommodating the end of the rivet pole, and the mounting hole is divided into a first mounting hole and a second mounting hole from top to bottom along the axial direction, and the first mounting hole and the second mounting hole have different sizes.

3. A pole sealed cover plate assembly according to claim 2, characterized in that: The size of the second mounting hole matches the size of the flat head, and the size of the first mounting hole is smaller than the size of the second mounting hole.

4. The pole sealed cover plate assembly according to claim 1, characterized in that: The thickness of the upper end of the second tapered portion is smaller than that of the lower end.

5. The pole sealed cover plate assembly according to claim 1, characterized in that: The two ends of the sealing member are respectively provided with a first step and a second step extending outward along the inner circumference.

6. The pole sealed cover plate assembly according to claim 1, characterized in that: The other end of the rivet pole is connected to an upper pressing block, and the upper pressing block is separated from the top cover plate by an upper insulating bracket.

7. The pole sealed cover plate assembly according to claim 1, characterized in that: The seal is formed by injection molding.

8. A battery cell, characterized in that: include: A pole group, wherein the positive pole ear and the negative pole ear of the pole group are located on the same side; a housing having an open end; According to the cover plate assembly as described in any one of claims 1 to 7, a positive electrode mounting hole and a negative electrode mounting hole are respectively provided at both ends of the top cover plate, a safety valve is provided in the middle of the top cover plate, and a liquid injection hole is provided between the safety valve and the negative electrode mounting hole.

9. A battery cell according to claim 8, characterized in that: Repair holes are arranged on the top cover plate at positions corresponding to the supporting parts at both ends of the lower insulating bracket.

10. The battery cell according to claim 8, characterized in that: The positive electrode mounting hole and the negative electrode mounting hole are respectively provided with two, and the rivet poles are correspondingly provided with two positive poles and two negative poles. The positive pole passes through the positive pole mounting hole to connect the positive pole adapter plate, and the negative pole passes through the negative pole mounting hole to connect the negative pole adapter plate. The two sealing members respectively isolate the positive pole and the top cover plate, and the negative pole and the top cover plate.

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