Top cover assembly, single battery and assembling method of single battery

Abstract

The invention is suitable for the technical field of batteries, and discloses a top cover assembly, a single battery and an assembly method thereof. According to the invention, the top cover assembly comprises a top cover and an anti-explosion sheet, the top cover is provided with a first liquid injection port, and the first liquid injection port is used for allowing an electrolyte to pass through; the anti-explosion sheet is connected with the top cover and covers and seals the first liquid injection opening; wherein first matching structures which are matched with each other are arranged at the first position between the top cover and the anti-explosion sheet, and second matching structures which are matched with each other are arranged at the second position between the top cover and the anti-explosion sheet. According to the explosion-proof device, the first matching structure and the second matching structure which are used for limiting each other are arranged between the top cover and the explosion-proof piece, and the first matching structure and the second matching structure can ensure that the explosion-proof piece is accurately placed at the preset position, so that better connection strength between the explosion-proof piece and the top cover is ensured. In addition, when the internal pressure of the single battery is too large, the first liquid injection port exhausts air and ejects the anti-explosion sheet, so that the first liquid injection port is reused, punching on the top cover is reduced, and the strength of the top cover is improved.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more particularly to a top cover assembly, a single battery cell, and an assembly method thereof. Background Technology

[0002] Current new energy battery cells are equipped with dedicated electrolyte injection holes and dedicated vent holes for explosion-proof sheets (for timely discharge of internal gas in case of battery malfunction). The explosion-proof sheet is welded and sealed to the explosion-proof vent hole of the battery cell top cover assembly before electrolyte injection. This increases the number of openings on the top cover, thereby reducing its strength. In addition, the connection strength between the explosion-proof sheet and the top cover is not high. Summary of the Invention

[0003] One object of the present invention is to provide a top cover assembly, a single battery cell and an assembly method thereof, which aims to solve the technical problems of top cover strength and the connection strength between the explosion-proof sheet and the top cover.

[0004] To achieve the above objectives, the present invention provides a solution as follows: a top cover assembly, the top cover assembly including a top cover and an explosion-proof sheet, the top cover having a first liquid injection port for allowing electrolyte to pass through; the explosion-proof sheet being connected to the top cover and sealing the first liquid injection port; wherein, a first mating structure mutually adaptable to each other is provided between the top cover and the explosion-proof sheet at a first position, and a second mating structure mutually adaptable to each other is provided at a second position.

[0005] In one implementation, the top cover protrudes away from the explosion-proof sheet to form a functional part, and the first liquid injection port is opened on the functional part, with a gap space formed between the functional part and the explosion-proof sheet.

[0006] In one implementation, the explosion-proof sheet is provided with annular grooves, and the projection of the first injection port of the explosion-proof sheet falls within the area enclosed by the annular grooves.

[0007] In one embodiment, the first mating structure includes a protrusion surrounding the first injection port and a groove on the explosion-proof sheet, the groove and the protrusion engaging; the second mating structure includes a first groove on the top cover, the first groove being located on the side of the protrusion away from the first injection port, and the edge of the explosion-proof sheet being accommodated in the first groove.

[0008] In one embodiment, the top cover is also provided with a second groove, which is located on the side of the protrusion near the first injection port, and the explosion-proof sheet is at least partially accommodated in the second groove.

[0009] In one implementation, the explosion-proof sheet and the bottom of the second tank are spaced apart along the axial direction of the first injection port.

[0010] In one embodiment, the top cover assembly also includes a protective sheet, on the side of the explosion-proof sheet away from the groove, an annular boss is formed, and the protective sheet is attached to the annular boss.

[0011] In one embodiment, the explosion-proof sheet has a second injection port opposite to the first injection port, the protrusion supports the area of ​​the explosion-proof sheet where the second injection port is located, and the top cover has an exhaust hole in the area opposite to the explosion-proof sheet; the top cover assembly also includes a sealing element that blocks the second injection port.

[0012] To achieve the above objectives, another solution provided by the present invention is: a single battery cell, which includes a bare cell, a casing, and a top cover assembly as described above, wherein the bare cell is placed in the casing, and the top cover assembly is connected to the casing.

[0013] To achieve the above objectives, another solution provided by the present invention is: a method for assembling a single battery cell, the method comprising assembling a bare cell into a housing; welding the top cover of a top cover assembly to the housing; injecting electrolyte into the housing through a first liquid injection port of the top cover assembly; adapting and connecting the explosion-proof sheet of the top cover assembly and the top cover through a first mating structure at a first position and a second mating structure at a second position, and fixing them by welding at least one of them.

[0014] Compared with existing technologies, this invention features a top cover assembly comprising a top cover and an explosion-proof sheet. The top cover has a first electrolyte inlet for allowing electrolyte to pass through, facilitating the use of individual batteries during electrolyte filling. The explosion-proof sheet is connected to the top cover and seals the first electrolyte inlet. When the internal pressure of the individual battery is too high, the explosion-proof sheet is opened by venting through the first electrolyte inlet, thus reusing the first electrolyte inlet and reducing the need for drilling holes in the top cover, thereby improving the strength of the top cover. Furthermore, a first and second mating structure are provided between the top cover and the explosion-proof sheet to limit their mutual positioning. This ensures that the explosion-proof sheet is accurately placed in a predetermined position, ensuring better connection strength between the explosion-proof sheet and the top cover. Additionally, the first and second mating structures have partial limiting structures on the top cover, further enhancing the strength of the top cover and the explosion-proof sheet. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of the first embodiment of the top cover assembly provided in this invention;

[0017] Figure 2 This is a cross-sectional schematic diagram of the first embodiment of the top cover assembly provided in this invention;

[0018] Figure 3 This is provided by the embodiments of the present invention. Figure 2 Schematic diagram of the structure of region A in the middle;

[0019] Figure 4 This is a schematic diagram of the structure of the second embodiment of the top cover assembly provided in this invention;

[0020] Figure 5 This is a cross-sectional schematic diagram of a second embodiment of the top cover assembly provided in this invention;

[0021] Figure 6 This is provided by the embodiments of the present invention. Figure 5 A schematic diagram of the structure of region B in the middle.

[0022] Explanation of icon numbers:

[0023] Top cover 10, first injection port 11, protrusion 12, first groove 13, second groove 14, functional part 17;

[0024] 18. Interval space, 19. Vent hole, 20. Explosion-proof plate, 21. Groove, 22. Annular boss, 24. Second injection port, 25. Annular groove, 26. Limiting part, 30. Protective plate, 40. Seal. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0027] Please see Figures 1 to 3 , Figure 1 This is a schematic diagram of the structure of the first embodiment of the top cover assembly provided in this invention. Figure 2 This is a cross-sectional schematic diagram of the first embodiment of the top cover assembly provided in this invention. Figure 3 This is provided by the embodiments of the present invention. Figure 2 A schematic diagram of the structure of region A in the middle.

[0028] This application protects a single-cell battery, which includes a bare cell, a casing, and a top cover assembly. The bare cell is placed in the casing, which also contains electrolyte. The top cover assembly is connected to the casing and seals the casing.

[0029] The top cover assembly includes a top cover 10 and an explosion-proof plate 20. The top cover 10 has a first liquid injection port 11 for allowing electrolyte to pass through. The explosion-proof plate 20 is connected to the top cover 10 and seals the first liquid injection port 11. A first mating structure is provided between the top cover 10 and the explosion-proof plate 20 at a first position, and a second mating structure is provided at a second position. The first mating structure confines the explosion-proof plate 20 at the first position to a predetermined position on the top cover 10, and the second mating structure confines the explosion-proof plate 20 at the second position to the predetermined position on the top cover 10. The explosion-proof plate 20 is mainly used to be pushed open when the pressure in the housing exceeds a preset value, thereby facilitating pressure release from the housing.

[0030] To enable those skilled in the art to gain a further understanding of this application, the applicant will explain the specific assembly method of a single cell:

[0031] 1: Assemble the bare battery cells into the casing;

[0032] 2: Weld the top cover 10 of the top cover assembly to the housing;

[0033] 3: Electrolyte is injected into the housing through the first injection port 11 on the top cover 10;

[0034] 4: Connect the explosion-proof sheet 20 and the top cover 10 of the top cover assembly by means of a first mating structure in a first position and a second mating structure in a second position, and fix them by welding at least one of them.

[0035] In this embodiment, the top cover assembly includes a top cover 10 and an explosion-proof sheet 20. The top cover 10 has a first electrolyte inlet 11, which allows electrolyte to pass through, facilitating the use of individual cells during electrolyte filling. The explosion-proof sheet 20 is connected to the top cover 10 and seals the first electrolyte inlet 11. When the internal pressure of the individual cell is too high, the explosion-proof sheet 20 is opened by venting through the first electrolyte inlet 11, thereby reusing the first electrolyte inlet 11 and reducing the need for drilling holes in the top cover 10. A first mating structure and a second mating structure are provided between the top cover 10 and the explosion-proof sheet 20 to limit each other. The first mating structure limits the explosion-proof sheet 20 to a predetermined position on the top cover 10 at a first position, and the second mating structure limits the explosion-proof sheet 20 to a predetermined position on the top cover 10 at a second position. The first and second mating mechanisms ensure that the explosion-proof sheet 20 is accurately placed at the predetermined position, ensuring better connection strength between the explosion-proof sheet 20 and the top cover 10. In addition, the first and second mating structures have local limiting structures on the top cover 10, which can strengthen the top cover 10 and the explosion-proof sheet 20.

[0036] Furthermore, the explosion-proof sheet 20 is welded onto the top cover 10 to cover the first liquid injection port 11, thus also sealing the individual battery cells and saving on the cost of sealing components (sealing aluminum nails, sealing rubber plugs, sealing steel nails, glue, etc.) for the first liquid injection port 11. The explosion-proof sheet 20 is assembled after liquid injection, and the liquid injection process does not affect the performance of the explosion-proof sheet 20.

[0037] In one embodiment, the top cover 10 protrudes away from the explosion-proof sheet 20 to form a functional part 17. The functional part 17 extends toward the interior of the housing, and a first liquid injection port 11 is formed on the functional part 17. A gap space 18 is formed between the functional part 17 and the explosion-proof sheet 20. The advantage of the gap space 18 is that it ensures that the explosion-proof sheet 20 and the functional part 17 do not directly contact each other. When the pressure in the housing is too high, the pressure can be evenly transmitted to the explosion-proof sheet 20 through the gap space 18, thereby achieving the effect of balancing the pressure. In addition, the explosion-proof sheet 20 will deform and generate internal stress during installation, and the gap space 18 can effectively avoid the deformation of the explosion-proof sheet 20.

[0038] Secondly, the functional part 17 extends toward the interior of the housing, occupying part of the housing space, so that part of the space of the top cover 10 can be freed up for the use of the explosion-proof sheet 20. The explosion-proof sheet 20 is at least partially housed in the top cover 10, so that the individual battery can be made shorter in the height direction.

[0039] Furthermore, the explosion-proof disc 20 is provided with annular notches 25, and the projection of the first injection port 11 of the explosion-proof disc 20 falls within the area enclosed by the annular notches 25. The annular notches 25 are the thinnest points in the explosion-proof disc 20. When the explosion-proof disc 20 is subjected to pressure, it preferentially breaks at the annular notches 25. The first injection port 11 is directly opposite the area enclosed by the annular notches 25, so when the shell pressure is ejected from the first injection port 11, force can be directly applied to the area corresponding to the annular notches 25, thereby quickly breaking the annular notches 25.

[0040] In one embodiment, the first mating structure includes a protrusion 12 surrounding the first injection port 11 and a groove 21 on the explosion-proof sheet 20. The groove 21 and the protrusion 12 are mated together. The protrusion 12 is disposed on the top cover 10 and the groove 21 is disposed on the explosion-proof sheet 20. The top cover 10 and the explosion-proof sheet 20 are limited together by the mutual mating of the groove 21 and the protrusion 12 to prevent the explosion-proof sheet 20 from moving relative to the top cover 10.

[0041] The second mating structure includes a first groove 13 on the top cover 10, located on the side of the protrusion 12 away from the first injection port 11, and the edge of the explosion-proof disc 20 is accommodated in the first groove 13. The mating of the explosion-proof disc 20 and the first groove 13 further prevents the explosion-proof disc 20 from moving relative to the top cover 10. After the first and second mating structures are mated together, the edge of the explosion-proof disc 20 is welded to the first groove 13.

[0042] In this embodiment, the first mating structure uses the protrusion 12 and the groove 21 to fix the explosion-proof sheet 20 at a predetermined position on the top cover 10. Then, the second mating structure uses the first groove 13 to fit the edge of the explosion-proof sheet 20 to further precisely position the contact position between the explosion-proof sheet 20 and the top cover 10, so as to weld the edge of the explosion-proof sheet 20 to the first groove 13.

[0043] The raised strip 12 also provides support for the explosion-proof disc 20 and limits circumferential stress deformation of the explosion-proof disc 20, protecting it from stress deformation that could affect its explosion-proof performance. The raised strip 12 also blocks liquid overflowing during the injection process, preventing it from flowing to the welding point between the explosion-proof disc 20 and the top cover 10 plate, thus avoiding interference with the welding.

[0044] Furthermore, the edge of the explosion-proof sheet 20 does not extend beyond the first groove 13, and the edge of the explosion-proof sheet 20 is completely contained within the first groove 13, thereby ensuring the flatness of the contact area between the explosion-proof sheet 20 and the top cover 10, which facilitates the implementation of the welding process.

[0045] In another embodiment, the top cover 10 also has a second groove 14, located on the side of the protrusion 12 near the first liquid injection port 11. The first groove 13 and the second groove 14 are located on opposite sides of the protrusion 12. The explosion-proof piece 20 is at least partially accommodated in the second groove 14. The explosion-proof piece 20 located in the first groove 13 and the second groove 14 can abut against the opposite two sides of the protrusion 12, or it can abut against one of the opposite two sides of the protrusion 12. In this embodiment, at least part of the explosion-proof piece 20 is accommodated in the second groove 14 on the top cover 10, thereby allowing part of the space of the top cover 10 to be occupied by the explosion-proof piece 20. The explosion-proof piece 20 can reduce the occupation of the external space of the single battery, thereby shortening the height of the single battery.

[0046] Furthermore, along the axial direction of the first injection port 11, the explosion-proof plate 20 and the second groove 14 are spaced apart. The advantage of this spaced-out arrangement is that it ensures the bottoms of the explosion-proof plate 20 and the second groove 14 do not directly contact each other. When the pressure inside the housing is excessive, the pressure can be evenly transmitted to the explosion-proof plate 20, thus achieving a pressure equalization effect. Additionally, the explosion-proof plate 20 will deform during installation, generating internal stress. This effectively prevents the deformation of the explosion-proof plate 20 from supporting the top cover 10.

[0047] The top cover assembly also includes a protective plate 30. An annular boss 22 is formed on the side of the explosion-proof plate 20 away from the groove 21, and the protective plate 30 is attached to the annular boss 22. The annular boss 22 is the highest point of the explosion-proof plate 20, and the protective plate 30, attached to the annular boss 22, is located at the very top of the explosion-proof plate 20. When external dust, water stains, or other contaminants move towards the explosion-proof plate 20, the protective plate 30 can preferentially contact the contaminants and isolate them from the explosion-proof plate 20. Furthermore, it has at least the following advantages: 1. The annular boss 22 can enhance the strength and rigidity of the explosion-proof plate 20, preventing deformation during assembly; 2. The annular boss 22 acts like a dam, dividing the explosion-proof plate 20 into inner and outer areas, preventing heat from spreading from the outside to the inside during welding of the explosion-proof plate 20 and the top cover 10; 3. Under strong external impact, the annular boss 22 is the first to be impacted, thus protecting the rest of the explosion-proof plate 20 from impact.

[0048] Please see Figures 4 to 6 , Figure 4 This is a schematic diagram of the structure of the second embodiment of the top cover assembly provided in this invention. Figure 5 This is a cross-sectional schematic diagram of a second embodiment of the top cover assembly provided in this invention. Figure 6 This is provided by the embodiments of the present invention. Figure 5 A schematic diagram of the structure of region B in the middle.

[0049] The explosion-proof plate 20 has a second injection port 24 opposite to the first injection port 11. The protrusion 12 supports the area of ​​the explosion-proof plate 20 where the second injection port 24 is located. The top cover 10 has a vent 19 in the area directly opposite the explosion-proof plate 20. The top cover assembly also includes a sealing element 40, which blocks the second injection port 24. The user injects liquid into the first injection port 11 through the second injection port 24. When the pressure in the housing is too high, the pressure is released to the explosion-proof plate 20 through the vent 19 and the first injection port 11. The explosion-proof plate 20 can be opened at the annular notch 25 or at the second injection port 24, which is not limited here.

[0050] In this embodiment, the electrolyte injection hole of the individual battery is located on the explosion-proof sheet 20, thereby saving space on the top cover 10. In addition, the protrusion 12 supports the area of ​​the explosion-proof sheet 20 where the second electrolyte injection port 24 is located. This reduces the torque stress on the explosion-proof valve caused by the pressure of the injection head when injecting electrolyte into the battery cell, and also reduces the impact of external forces such as bumps and presses on the explosion-proof sheet 20.

[0051] Furthermore, the axis of the first injection port 11 and the axis of the second injection port 24 can coincide or approximately coincide, so that when liquid is injected through the second injection port 24, the liquid can immediately enter the first injection port 11.

[0052] Furthermore, the first slot 13 can be made of, for example Figure 3 A step shown can also be like... Figure 6 The two steps shown can be understood to be replaced by other numbers of steps. The more steps there are, the better the limiting effect.

[0053] Furthermore, the thickness of the explosion-proof sheet 20 within the area enclosed by the annular notch 25 is greater than 0.4 mm to provide sufficient strength and reduce the impact of pressure applied inside and outside the annular notch 25 on the annular notch 25.

[0054] It should also be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on the other component or may be connected to an intermediary component. When a component is referred to as being "connected to" another component, it can be directly connected to the other component or indirectly connected to the other component through an intermediary component.

[0055] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0056] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A top cover assembly, characterized in that, include: The top cover (10) has a first liquid injection port (11) for allowing electrolyte to pass through; as well as An explosion-proof sheet (20) is connected to the top cover (10) and seals the first injection port (11); The top cover (10) and the explosion-proof sheet (20) are provided with a first mating structure at a first position and a second mating structure at a second position.

2. The top cover assembly according to claim 1, characterized in that, The top cover (10) protrudes away from the explosion-proof sheet (20) to form a functional part (17), the first liquid injection port (11) is opened on the functional part (17), and a gap space (18) is formed between the functional part (17) and the explosion-proof sheet (20).

3. The top cover assembly according to claim 1, characterized in that, The explosion-proof sheet (20) is provided with annular grooves (25), and the first injection port (11) is located within the area enclosed by the annular grooves (25) when the projection of the explosion-proof sheet (20) falls on it.

4. The top cover assembly according to any one of claims 1-3, characterized in that, The first mating structure includes a protrusion (12) surrounding the first injection port (11) and a groove (21) on the explosion-proof sheet (20), wherein the groove (21) and the protrusion (12) are mated; The second mating structure includes a first groove (13) on the top cover (10), the first groove (13) being located on the side of the protrusion (12) away from the first injection port (11), and the edge of the explosion-proof sheet (20) being accommodated in the first groove (13).

5. The top cover assembly according to claim 4, characterized in that, The top cover (10) is also provided with a second groove (14), which is located on the side of the protrusion (12) near the first injection port (11), and the explosion-proof sheet (20) is at least partially accommodated in the second groove (14).

6. The top cover assembly according to claim 5, characterized in that, The explosion-proof plate (20) and the bottom of the second groove (14) are spaced apart along the axial direction of the first injection port (11).

7. The top cover assembly according to claim 4, characterized in that, The top cover assembly also includes a protective sheet (30), and the explosion-proof sheet (20) has an annular boss (22) formed on the side away from the groove (21), and the protective sheet (30) is attached to the annular boss (22).

8. The top cover assembly according to claim 4, characterized in that, The explosion-proof sheet (20) has a second injection port (24) opposite to the first injection port (11), the protrusion (12) supports the area of ​​the explosion-proof sheet (20) where the second injection port (24) is located, and the top cover (10) has an exhaust hole (19) in the area of ​​the explosion-proof sheet (20) directly opposite to the area of ​​the explosion-proof sheet (20). The top cover assembly also includes a seal (40) that blocks the second injection port (24).

9. A single-cell battery, characterized in that, The single battery cell includes a bare cell, a housing, and a top cover assembly as described in any one of claims 1 to 8, wherein the bare cell is placed in the housing, and the top cover assembly is connected to the housing.

10. A method for assembling a single battery cell, characterized in that, The assembly method includes: The bare battery cell is assembled into the housing; The top cover (10) of the top cover assembly is welded together with the housing; Electrolyte is injected into the housing through the first injection port (11) of the top cover assembly; The explosion-proof sheet (20) of the top cover assembly and the top cover (10) are adapted and connected by a first mating structure at a first position and a second mating structure at a second position, and are fixed by welding at least one of them.

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