Battery cover plate assembly and battery cell
By optimizing the structural design of the battery cover assembly, ensuring the insulating contact between the seal ring and the conductive column and extending the electrolyte penetration path, while keeping the explosion-proof valve away from the pole column, solving the insulation failure and thermoelectric short circuit of the battery cell, achieving an extremely safe battery cell.
Patent Information
- Application Number
- CN202421744041.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-22
- Publication Date
- 2025-07-25
- Estimated Expiration
- 2034-07-22
AI Technical Summary
During use, existing battery cell cover assembly is prone to gaps between the seal ring and the lower plastic due to processing tolerances or unreasonable design, resulting in insulation failure, which leads to safety problems, such as shell corrosion, increased self-discharge or short circuit of the positive and negative electrodes. Improper setup of explosion-proof valves can easily lead to high-heat and high-humidity gases being sprayed out, triggering short circuits, and causing safety accidents.
By rationally designing the components of the battery cover assembly, ensuring the insulating contact between the sealing ring and the conductive column, using an inclined surface design to extend the electrolyte penetration path, and keeping the explosion-proof valve away from the positive and negative poles, achieving thermoelectric separation.
It effectively avoids shell corrosion or self-discharge increase caused by insulation failure, achieves the ultimate safety of the battery cell, avoids short circuits of positive and negative electrodes and thermoelectric separation, and improves the safety performance of the battery.
Smart Images
Figure CN223156151U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of battery manufacturing, and particularly relates to a battery cover plate assembly and a battery cell. Background Art
[0002] The statements herein only provide background art related to the utility model, and do not necessarily constitute prior art.
[0003] Currently, with the rapid development of new energy, the application of power batteries is becoming more and more extensive. With the concepts of ultimate performance, ultimate safety, and ultimate cost put forward, the ultimate safety performance of power battery cells is closely related to the safety of the whole vehicle and consumers. The insulation performance of the insulating parts in the cell, the sealing performance of the sealing parts, and the pressure relief rate and pressure relief direction of the pressure relief mechanism are all crucial to the safety performance of the cell.
[0004] At present, the commonly used and mature structure of the cover plate assembly of battery cells is a riveting structure. The light cover plate compresses the sealing ring with the pole column and cooperates with the lower plastic to conduct insulation sealing. However, due to the machining tolerances, assembly tolerances or unreasonable designs of the actual parts, there will be a gap between the sealing ring and the lower plastic. Before the cover plate is used, the gap is filled with air, and a large voltage is required to break down here, so the cover plate will not have an insulation failure problem. However, during the use of the cover plate, it is inevitable to come into contact with humid gas or liquid. At this time, when a voltage is applied, the resistance at this gap position changes from air resistance to liquid or humid air resistance, and the resistance decreases significantly, resulting in insulation failure. Among them, if the negative pole insulation fails, it will lead to a low shell voltage, and then the shell or explosion-proof valve will be corroded; if the positive pole insulation fails, it will lead to a high shell voltage, increased self-discharge, external insulation failure, and safety problems such as explosion.
[0005] On the other hand, in the existing design, the explosion-proof valve is usually arranged on the cell cover plate and is arranged in the same direction as the positive pole column and / or the negative pole column. When the explosion-proof valve is opened, a large amount of high-temperature, high-humidity, and highly corrosive gas, liquid or solid material sprays out from the explosion-proof valve, which is very easy to contact the positive and negative pole columns of adjacent cells or modules, thereby triggering further short circuits, and the entire battery pack is more likely to get out of control, causing safety accidents or problems. Summary of the Utility Model
[0006] In view of the above problems and defects existing in the prior art, the present utility model provides a battery cover assembly and a battery cell. Through the reasonable design of each component of the cover assembly, it is possible to avoid the problem of insulation failure due to the presence of electrolyte or in a high-humidity environment during the use of the battery or when the cover assembly undergoes weather resistance verification, thereby avoiding safety problems such as shell corrosion caused by low shell voltage, increased self-discharge caused by high shell voltage, or direct micro-short circuit between the positive and negative electrodes of the cell; moreover, for the battery cell equipped with this cover assembly, the explosion-proof valve is designed away from the positive and negative electrode posts to achieve thermal and electrical separation; through the above two methods, the ultimate safety of the battery cell is realized.
[0007] In order to achieve the above object, the present utility model adopts the following technical solutions:
[0008] In the first aspect, the present utility model proposes a battery cover assembly.
[0009] A battery cover assembly includes an electrode post, an upper plastic, a light cover plate, a sealing ring, and a lower plastic; wherein, the electrode post includes a conductive post and an aluminum block, and the conductive post includes a conductive post body; the aluminum block, the upper plastic, the light cover plate, and the lower plastic are all provided with through holes, and are sequentially and tightly sleeved on the conductive post body from top to bottom through the through holes, and the inner side walls of the upper plastic, the light cover plate, and the lower plastic are all in sealed and insulated contact with the conductive post body through the sealing ring;
[0010] The light cover plate matches with the lower plastic and jointly presses the sealing ring to form a stepped structure. The lower plastic boss and the lower surface of the light cover plate are in close contact with the upper surface of the first step of the sealing ring, and the bottom surface of the lower plastic is provided with a lower plastic groove. A material swelling space is formed between the inner side wall of the lower plastic groove and the outer side wall of the first step of the sealing ring.
[0011] In a further technical solution, at least part of the inner side wall of the lower plastic groove is set as an inclined surface, and the inclined surface is inclined in a direction away from the conductive post body.
[0012] In a further technical solution, the light cover plate matches with the lower plastic and jointly presses the sealing ring, and the sealing ring forms a stepped structure. The lower surface of the light cover plate presses the upper surface of the first step of the sealing ring to form a first sealing area; the lower surface of the lower plastic boss presses the upper surface of the first step of the sealing ring to form a second sealing area.
[0013] In a further technical solution, an upper plastic is provided between the aluminum block and the light cover plate, the inner side wall of the upper plastic is in contact with the sealing ring, and insulation and sealing between the conductive post body and the light cover plate are achieved through the upper plastic and the sealing ring.
[0014] In a further technical solution, at least part of the inner side wall of the upper plastic is set as an inclined surface, and the inclined surface is inclined in a direction away from the conductive post body.
[0015] Further technical solution: The conductive post further includes a conductive post base, and the conductive post body and the conductive post base are of an integral structure; there is a lower plastic between the optical cover plate and the conductive post base, and the inner side walls of the optical cover plate and the lower plastic are in contact with the sealing ring. Insulating sealing between the optical cover plate and the conductive post is achieved through the lower plastic and the sealing ring.
[0016] Further technical solution: The top surface of the lower plastic further has a lower plastic boss, the lower plastic boss is an annular boss, and the lower plastic groove provided on the bottom surface of the lower plastic is located below the lower plastic boss. The lower plastic groove is a circular groove and surrounds the through hole in the middle position of the lower plastic.
[0017] The optical cover plate is provided with an optical cover plate groove matching the lower plastic boss, and the optical cover plate groove is an annular groove; the lower plastic boss is embedded in the optical cover plate groove to complete the matching of the lower plastic and the optical cover plate.
[0018] Further technical solution: The diameter of the upper plastic groove is greater than or equal to the inner diameter of the upper plastic boss and less than or equal to the outer diameter of the upper plastic boss.
[0019] The inner diameter of the optical cover plate groove is less than or equal to the inner diameter of the upper plastic boss, and the outer diameter of the optical cover plate groove is greater than or equal to the outer diameter of the upper plastic boss; the depth of the optical cover plate groove is less than or equal to the height of the upper plastic boss.
[0020] In a second aspect, the present utility model proposes a battery cell.
[0021] A battery cell includes a housing, on which a battery cover plate assembly as described in the first aspect is welded, and at least one explosion-proof valve is welded on the housing, and the explosion-proof valve and the battery cover plate are not arranged on the same surface of the housing.
[0022] Further technical solution: An explosion-proof valve protection patch is pasted on the outside of the explosion-proof valve.
[0023] Compared with the prior art, the present utility model has the following beneficial effects:
[0024] The present utility model provides a battery cover plate assembly and a battery cell. Through the reasonable design of each component of the cover plate assembly, problems such as insulation failure due to electrolyte or in a high-humidity environment during the use of the battery or when the cover plate assembly undergoes weather resistance verification are avoided, thereby avoiding safety problems such as shell corrosion caused by low shell voltage, increased self-discharge caused by high shell voltage, or direct micro-short circuit between the positive and negative electrodes of the cell; moreover, for the battery cell with this cover plate assembly, the explosion-proof valve is designed away from the positive and negative electrode posts to achieve thermal and electrical separation; through the above two methods, the ultimate safety of the battery cell is realized. Description of the Drawings
[0025] The accompanying drawings forming a part of the present utility model are used to provide a further understanding of the present utility model. The schematic embodiments and descriptions thereof of the present utility model are used to explain the present utility model and do not constitute an improper limitation to the present utility model.
[0026] Figure 1 is a schematic structural view of the battery cover assembly described in the present utility model;
[0027] Figure 2 is a cross-sectional view of the battery cover assembly described in the present utility model;
[0028] Figure 3 is the present utility model Figure 2 an enlarged schematic view of part A in;
[0029] Figure 4 is a schematic structural view of the lower plastic in the battery cover assembly described in the present utility model;
[0030] Figure 5 is a cross-sectional view of the middle part of the lower plastic in the battery cover assembly described in the present utility model;
[0031] Figure 6 is a schematic structural view of the light cover in the battery cover assembly described in the present utility model;
[0032] Figure 7 is a cross-sectional view of the middle part of the light cover in the battery cover assembly described in the present utility model;
[0033] Figure 8 is a schematic structural view of the battery cell described in the present utility model.
[0034] Wherein, 1, battery cell; 10, housing; 20, negative electrode cover assembly; 30, explosion-proof valve; 40, positive electrode cover assembly; 401, pole column; 402, light cover; 403, liquid injection hole; 404, lower plastic; 4011, aluminum block; 4012, conductive column; 4013, upper plastic; 4014, sealing ring; 4021, first sealing area; 4022, light cover groove; 4041, swelling space; 4042, second sealing area; 4043, lower plastic boss. Detailed implementation manners
[0035] It should be noted that the following detailed descriptions are all illustrative and are intended to provide further descriptions of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those of ordinary skill in the technical field to which the present application belongs.
[0036] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they specify the presence of features, steps, operations, devices, components, and / or combinations thereof.
[0037] Embodiment 1
[0038] This embodiment discloses a battery cover plate assembly, which can effectively improve the insulation and sealing performance of the cover plate assembly during use, thereby ensuring the safety of the battery cell. In practical applications, the battery cover plate assembly can be divided into a positive cover plate assembly and a negative cover plate assembly. The structures of the two cover plate assemblies are similar. The positive and negative cover plate assemblies are respectively arranged on the battery cell to achieve the transmission of the internal current of the cell to the module or battery pack.
[0039] Taking the positive cover plate assembly 40 as an example, as Figure 1 and Figure 2 shown, the battery cover plate assembly proposed in this embodiment includes a pole column 401, an upper plastic 4013, a light cover plate 402, a sealing ring 4014, and a lower plastic 404. Among them, the pole column includes a conductive column 4012 and an aluminum block 4011. The conductive column 4012 includes a conductive column body and a conductive column base. The conductive column body is a cylindrical structure, and the conductive column base is a flat cylindrical bottom plate. The conductive column body and the conductive column base are an integrated structure, and they are integrally formed into the conductive column 4012. The aluminum block 4011, the upper plastic 4013, the light cover plate 402, and the lower plastic 404 are all provided with through holes, and are sequentially and tightly sleeved on the conductive column body from top to bottom through the through holes. Moreover, the inner side walls of the upper plastic 4013, the light cover plate 402, and the lower plastic 404 are in sealed and insulated contact with the conductive column body through the sealing ring. In addition, a liquid injection hole 403 is also provided on the light cover plate 402 to facilitate battery liquid injection.
[0040] Furthermore, as Figure 2 shown, the aluminum block 4011, the upper plastic 4013, the light cover plate 402, and the lower plastic 404 are sequentially and tightly sleeved on the conductive column body from top to bottom. Among them, an upper plastic 4013 is provided between the aluminum block 4011 and the light cover plate 402. The inner side wall of the upper plastic 4013 (i.e., the circumferential side wall of the through hole) is in contact with the sealing ring 4014. Insulation between the conductive column body and the light cover plate 402 is achieved through the upper plastic 4013 and the sealing ring 4014, and the sealing performance is achieved through the compression of the sealing ring 4014 to prevent insulation failure caused by external liquid entering.
[0041] Preferably, at least a part of the inner wall of the upper plastic 4013 is set as an inclined surface, and the inclined surface inclines away from the main body of the conductive post. During the riveting process, the conductive post expands and extrudes the sealing ring, thereby achieving insulating sealing. Through the above design of the upper plastic 4013 and the sealing ring 4014, insulation is achieved, and through the compression of the sealing ring 4014, sealing is achieved to prevent insulation failure caused by external liquid entering.
[0042] In addition, a lower plastic 404 is provided between the optical cover plate 402 and the conductive post base. The inner walls of the optical cover plate 402 and the lower plastic 404 are in contact with the sealing ring 4014. Insulation between the optical cover plate 402 and the conductive post is achieved through the lower plastic 404 and the sealing ring 4014, and sealing performance is achieved through the compression of the sealing ring 4014 to prevent insulation failure caused by external and internal liquid entering.
[0043] Specifically, as Figure 3 and Figure 4 shown, a lower plastic boss 4043 is provided on the top surface of the lower plastic 404. The lower plastic boss 4043 is an annular boss. A lower plastic groove is provided on the bottom surface of the lower plastic 404. The lower plastic groove is located below the lower plastic boss 4043, and the lower plastic groove is a circular groove surrounding the through hole at the middle position of the lower plastic 404; as Figure 6 shown, an optical cover plate groove 4022 matching the lower plastic boss 4043 is provided on the bottom surface of the optical cover plate 402. The optical cover plate groove 4022 is an annular groove.
[0044] Furthermore, as Figure 5 shown, the inner diameter of the lower plastic boss 4043 is L1, the outer diameter is L2, and 2mm ≤ L2 - L1 ≤ 4mm; the diameter L3 of the circular groove of the lower plastic 404 satisfies L1 ≤ L3 ≤ L2 and 1mm ≤ L2 - L3, that is, the diameter of the lower plastic groove is greater than or equal to the inner diameter of the lower plastic boss and less than or equal to the outer diameter of the lower plastic boss; the height H1 of the lower plastic boss 4043 satisfies 0.2mm ≤ H1 ≤ 1mm; as Figure 7 shown, an optical cover plate groove 4022 is provided at the mating position of the optical cover plate 402 and the lower plastic 404. The lower plastic boss 4043 is assembled into the optical cover plate groove 4022. The inner diameter L4 and the outer diameter L5 of the optical cover plate groove 4022 satisfy L4 ≤ L1 and L5 ≥ L2, that is, the inner diameter of the optical cover plate groove 4022 is less than or equal to the inner diameter of the lower plastic boss 4043, and the outer diameter of the optical cover plate groove 4022 is greater than or equal to the outer diameter of the lower plastic boss 4043 to facilitate the lower plastic boss 4043 to be embedded into the optical cover plate groove 4022. In addition, the depth H2 of the optical cover plate groove satisfies H2 ≤ H1. Preferably, H2 = H1, that is, the depth of the optical cover plate groove 4022 is equal to the height of the lower plastic boss 4043.
[0045] Furthermore, asFigure 3 As shown, the lower plastic boss 4043 of the lower plastic 404 is embedded in the light cover plate groove 4022 of the light cover plate 402. After the fitting is completed, the top surface of the lower plastic 404 is flush with and in contact with the bottom surface of the light cover plate 402. The inner side walls of the light cover plate 402 and the lower plastic 404 are in contact with and press the sealing ring 4014 to form a stepped structure. The lower surface of the lower plastic boss 4043 and the lower surface of the light cover plate 402 are both in close contact with the upper surface of the first step of the sealing ring. A swelling space 4041 is formed between the inner side wall of the lower plastic groove and the outer side surface of the first step of the sealing ring.
[0046] Among them, the lower surface of the light cover plate 402 presses the upper surface of the first step of the sealing ring 4014 to form a first sealing area 4021, and the lower surface of the lower plastic boss 4043 presses the upper surface of the first step of the sealing ring to form a second sealing area 4042. The light cover plate 402 and the lower plastic 404 simultaneously squeeze and compress the sealing ring 4014. The sealing ring material in the first and second sealing areas is pressed into the swelling space 4041, and the swelling space is filled. Even if the swelling space is not fully filled due to the dimensional and positional tolerances of each part, there will be no direct conduction between the two metals, thus avoiding insulation failure caused by the entry of electrolyte into this area, and eliminating problems such as shell corrosion with low shell voltage and increased self-discharge with high shell voltage.
[0047] Furthermore, at least part of the inner side wall of the lower plastic groove is set as an inclined surface, and the inclined surface is inclined in a direction away from the main body of the conductive post. Through this design, a reasonable match is formed between the swelling amount of the sealing ring and the volume of the swelling space, and the electrolyte penetration path is extended.
[0048] Through the above-mentioned cooperation of the lower plastic, the light cover plate, the sealing ring and the pole column, multi-channel insulation sealing is achieved, thereby avoiding insulation failure caused by creepage of the electrolyte between the two metals on the surface of the components, avoiding corrosion with low shell voltage, self-discharge and increased heat generation with high shell voltage, and conduction short circuit between the positive and negative electrodes.
[0049] Through the above design, it is ensured that when the battery cover plate assembly is immersed in the electrolyte, the electrolyte cannot enter between any two metal parts (such as the main body of the conductive post of the light cover plate and the pole column, the conductive post base of the light cover plate and the pole column, the aluminum block and the light cover plate, etc.), avoiding insulation failure problems that may occur due to the presence of electrolyte or in a high-humidity environment during the use of the battery or when the cover plate assembly undergoes weather resistance verification, thereby avoiding safety problems such as shell corrosion caused by low shell voltage, increased self-discharge caused by high shell voltage, or direct micro short circuit between the positive and negative electrodes of the battery cell.
[0050] Embodiment 2
[0051] This embodiment proposes a battery cell 1, as Figure 8As shown, it includes a housing 10, on which a battery cover assembly (including a positive cover assembly 40 and a negative cover assembly 20) as proposed in the first embodiment is welded. At least one explosion-proof valve 30 is welded on the housing, and the explosion-proof valve and the battery cover are not arranged on the same surface of the housing.
[0052] Furthermore, the above-mentioned housing 10 is a steel shell or an aluminum shell. The steel shell is integrally made of stainless steel or nickel-plated steel, etc., and the aluminum shell is integrally made of 3003 aluminum or 3006 aluminum, etc.; the housing has equal wall thickness or unequal wall thickness. The top and bottom surfaces of the housing are provided with a battery cover assembly, and at least one explosion-proof valve is arranged on the side surface of the housing. The explosion-proof valve can be welded to the housing or integrally processed with the housing. In addition, an explosion-proof valve protection patch is pasted on the outside of the explosion-proof valve to protect the explosion-proof valve from being damaged during the manufacturing process.
[0053] Through the design of the explosion-proof valve away from the pole column, thermoelectric separation can be achieved, and the safety performance of the battery cell and the module can be improved.
[0054] Although the specific implementation manners of the present invention are described above in conjunction with the accompanying drawings, it is not a limitation to the protection scope of the present invention. Those skilled in the art should understand that on the basis of the technical solution of the present invention, various modifications or deformations that can be made by those skilled in the art without creative labor are still within the protection scope of the present invention.
Claims
1. A battery cover plate assembly, characterized in that, It includes a terminal post, an upper plastic, a light cover plate, a sealing ring, and a lower plastic. Among them, the terminal post includes a conductive post and an aluminum block. The conductive post includes a conductive post body. The aluminum block, the upper plastic, the light cover plate, and the lower plastic are all provided with through holes, and are sequentially and tightly sleeved on the conductive post body from top to bottom through the through holes. Moreover, the inner side walls of the upper plastic, the light cover plate, and the lower plastic are in sealed and insulated contact with the conductive post body through the sealing ring. The light cover plate matches with the lower plastic and jointly squeezes the sealing ring to form a stepped structure. The lower plastic boss and the lower surface of the light cover plate are in close contact with the upper surface of the first step of the sealing ring. The bottom surface of the lower plastic is provided with a lower plastic groove, and a material swelling space is formed between the inner side wall of the lower plastic groove and the outer side wall of the first step of the sealing ring.
2. The battery cover plate assembly according to claim 1, wherein At least part of the inner side wall of the lower plastic groove is set as an inclined surface, and the inclined surface inclines in a direction away from the conductive post body.
3. The battery cover assembly according to claim 1, wherein, The light cover plate matches with the lower plastic and jointly squeezes the sealing ring. The sealing ring forms a stepped structure. The lower surface of the light cover plate presses tightly on the upper surface of the first step of the sealing ring to form a first sealing area; the lower surface of the lower plastic boss presses tightly on the upper surface of the first step of the sealing ring to form a second sealing area.
4. The battery cover plate assembly according to claim 1, wherein, There is an upper plastic between the aluminum block and the light cover plate. The inner side wall of the upper plastic is in contact with the sealing ring. Insulating sealing between the conductive post body and the light cover plate is achieved through the upper plastic and the sealing ring.
5. The battery cover assembly according to claim 4, wherein, At least part of the inner side wall of the upper plastic is set as an inclined surface, and the inclined surface inclines in a direction away from the conductive post body.
6. The battery cover plate assembly according to claim 1, characterized in that, The conductive post further includes a conductive post base, and the conductive post body and the conductive post base are of an integrated structure. There is a lower plastic between the light cover plate and the conductive post base. The inner side walls of the light cover plate and the lower plastic are in contact with the sealing ring. Insulating sealing between the light cover plate and the conductive post is achieved through the lower plastic and the sealing ring.
7. The battery cover assembly according to claim 1, wherein, The top surface of the lower plastic is further provided with a lower plastic boss. The lower plastic boss is an annular boss. The lower plastic groove provided on the bottom surface of the lower plastic is located below the lower plastic boss. The lower plastic groove is a circular groove and surrounds the through hole at the middle position of the lower plastic. The light cover plate is provided with a light cover plate groove matching with the lower plastic boss. The light cover plate groove is an annular groove. The lower plastic boss is embedded in the light cover plate groove to complete the matching of the lower plastic and the light cover plate.
8. The battery cover plate assembly according to claim 7, characterized in that, The diameter of the upper plastic groove is greater than or equal to the inner diameter of the upper plastic boss and less than or equal to the outer diameter of the upper plastic boss. The inner diameter of the light cover plate groove is less than or equal to the inner diameter of the upper plastic boss, and the outer diameter of the light cover plate groove is greater than or equal to the outer diameter of the upper plastic boss. The depth of the light cover plate groove is less than or equal to the height of the upper plastic boss.
9. A battery cell, characterized in that, It includes a housing. The battery cover plate assembly as described in any one of claims 1-8 is welded on the housing. At least one explosion-proof valve is welded on the housing, and the explosion-proof valve and the battery cover plate are not arranged on the same surface of the housing.
10. The battery cell according to claim 9, characterized in that, An explosion-proof valve protection patch is pasted on the outside of the explosion-proof valve.