Cover assembly, cells and battery pack

Abstract

This application provides a cover plate assembly, a battery cell, and a battery pack, relating to the field of battery technology. The cover plate assembly includes a terminal post, a first metal component, a second metal component, a first sealing component, a current collector, and a second sealing component. The first metal component is ring-mounted around the terminal post. The second metal component is ring-mounted around the terminal post, along the axial direction of the terminal post, located on one side of the first metal component and connected to it. The first sealing component is ring-mounted between the terminal post and the second metal component. The current collector is connected to one end of the terminal post. The second sealing component is ring-mounted around the terminal post, with its two ends connected to the first metal component and the current collector, respectively. Through the above solution, this application can effectively prevent electrolyte from flowing from the mating area between the first metal component and the terminal post into the space between the first metal component and the second metal component. This avoids galvanic corrosion between the first and second metal components, helps ensure the structural strength of the first and second metal components, and thus improves the structural strength of the cover plate assembly.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to a cover plate assembly, a battery cell, and a battery pack. Background Technology

[0002] The mechanical strength and sealing performance of battery cell components are closely related to battery life. Currently, rubber (e.g., fluororubber) is used as the primary seal between the terminals and the cover plate in battery cell structures. However, rubber has poor aging resistance, and when exposed to high temperature and humidity in contact with the electrolyte for extended periods, it ages rapidly, leading to a higher probability of cell seal failure. This, in turn, results in a shorter battery cell lifespan.

[0003] In related technologies, to address the aging problem of rubber seals, rigid sealing materials are used to create rigid seals to seal the gap between the electrode post and the cover plate. These rigid sealing materials can be glass, graphite, or ceramics. Because these rigid sealing materials have high melting temperatures (i.e., high melting points), the material used to form the cover plate must have a higher melting point than the rigid sealing material to prevent deformation during sintering. Compared to aluminum cover plates, cover plates made of other metals with higher melting points are heavier, resulting in a heavier battery cell and negatively impacting its energy density.

[0004] Therefore, in related technologies, the cover plate is an assembly. The outer ring of the cover plate is a first metal with a lower density, such as aluminum. The inner ring, which is directly connected to the rigid seal, is a second metal with a higher melting point, such as stainless steel. Because the first and second metal parts of the cover plate are made of different materials, and different metals have different electrode potentials, a galvanic cell is formed when the connection between the first and second metal parts comes into contact with the electrolyte. The metal with the lower potential becomes the anode, which undergoes an oxidation reaction; that is, the anode loses electrons, resulting in galvanic corrosion (also known as contact corrosion or dissimilar metal corrosion). This reduces the reliability of the cover plate assembly and adversely affects the reliability of the battery cell. Utility Model Content

[0005] Embodiments of this application provide a cover plate assembly, a battery cell, and a battery pack, which can improve the reliability of the cover plate assembly.

[0006] In a first aspect, embodiments of this application provide a cover plate assembly, which includes a pole post, a first metal member, a second metal member, a first sealing member, a current collector, and a second sealing member; the first metal member is annularly disposed on the pole post; the second metal member is annularly disposed on the pole post, and along the axial direction of the pole post, the second metal member is located on one side of the first metal member and connected to the first metal member; the first sealing member is annularly disposed between the pole post and the second metal member; the current collector is connected to one end of the pole post; the second sealing member is annularly disposed on the pole post, and both ends of the second sealing member are respectively connected to the first metal member and the current collector.

[0007] In some embodiments, along the axial direction of the pole post, the second seal has a height dimension H1 that satisfies: 0.3mm ≤ H1 ≤ 3mm.

[0008] In some embodiments, the second seal has a thickness dimension D1 along the radial direction of the pole post, satisfying: 0.3mm≤D1≤6mm.

[0009] In some embodiments, the second seal is an elastic rubber ring. In the axial direction of the pole, the two ends of the second seal abut against the first metal part and the current collector, respectively, and the second seal is in a compressed state.

[0010] In some embodiments, the second seal is a sealant, and its two ends are respectively bonded to the first metal part and the manifold.

[0011] In some embodiments, the inner circumferential surface of the second seal is bonded to the outer circumferential surface of the pole.

[0012] In some embodiments, a recessed platform is provided on the side of the first metal member facing away from the current collector, and the second metal member is disposed in the recessed platform.

[0013] In some embodiments, a mating hole is provided at the bottom of the recessed platform, and an extension section protrudes from the side of the second metal member facing the bottom of the recessed platform. One end of the extension section and one end of the first sealing member both extend into the mating hole.

[0014] In some embodiments, the cover plate assembly further includes a first insulating member sleeved on the pole and located on the side of the first metal member facing the current collector.

[0015] In some embodiments, the inner peripheral side of the first insulating member is spaced apart from the current collector.

[0016] In some embodiments, the material of the first metal part includes aluminum, the material of the second metal part includes stainless steel; and / or, the first seal is a glass seal.

[0017] Secondly, embodiments of this application provide a battery cell, which includes a housing, an electrode assembly, and the aforementioned cover plate assembly; the housing has a receiving cavity; the electrode assembly is disposed in the receiving cavity; the outer periphery of a first metal member is connected to the housing, and a current collector is connected to the electrode assembly.

[0018] Thirdly, embodiments of this application provide a battery pack, which includes the aforementioned battery cells, and there are multiple battery cells electrically connected to each other.

[0019] The beneficial effects of the embodiments of this application are as follows:

[0020] In the embodiments of this application, by providing a second sealing element between the first metal component and the current collector, electrolyte can be effectively prevented from flowing from the mating portion between the first metal component and the electrode post into the space between the first metal component and the second metal component. This avoids galvanic corrosion between the first and second metal components, helps ensure the structural strength of the first and second metal components, and thus improves the structural strength of the cover plate assembly. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of the cover plate assembly provided in an embodiment of this application;

[0023] Figure 2 yes Figure 1 Enlarged view of point A in the middle;

[0024] Figure 3 This is the structural intent of the first metal component provided in the embodiments of this application;

[0025] Figure 4 This is the structural intent of the second metal component provided in the embodiments of this application;

[0026] Figure 5 This is a schematic diagram of the battery cell structure provided in an embodiment of this application;

[0027] Figure 6 This is a schematic diagram of a battery pack provided in an embodiment of this application.

[0028] Explanation of reference numerals in the attached figures:

[0029] 11-First metal component; 111-Counterpart; 112-Matching hole;

[0030] 12-Second metal part; 121-Extension section;

[0031] 13-Second seal; 131-First connecting surface; 132-Second connecting surface;

[0032] 200 - Cover plate assembly; 21 - Pole post; 22 - First seal;

[0033] 23-First insulating element;

[0034] 24-Current collector;

[0035] 300 - Cell; 31 - Housing; 32 - Electrode assembly; 33 - Receiving cavity;

[0036] 400 - Battery pack; 41 - Housing; 42 - Housing cover; 43 - Mounting cavity. Detailed Implementation

[0037] The technical solutions of the embodiments of this application 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 this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. In addition, it should be understood that the specific embodiments described herein are only for illustration and explanation of this application and are not intended to limit this application. In this application, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0038] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0039] The terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a product comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a product. Without further limitation, an element defined by the phrase “comprising one…” does not exclude the presence of other identical elements in a product that includes said element.

[0040] The following combination Figures 1 to 6 The present application provides a detailed description of a cover plate assembly 200, a battery cell 300, and a battery pack 400 provided in the embodiments of this application.

[0041] Please see Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of the structure of the cover plate assembly 200 provided in an embodiment of this application. Figure 2 yes Figure 1 Enlarged view at point A. In a first aspect, embodiments of this application provide a cover plate assembly 200. The cover plate assembly 200 includes a pole post 21, a first metal member 11, a second metal member 12, a first sealing member 22, a current collector 24, and a second sealing member 13. The first metal member 11 is circumferentially disposed on the pole post 21. The second metal member 12 is circumferentially disposed on the pole post 21. Along the axial direction of the pole post 21, the second metal member 12 is located on one side of the first metal member 11 and connected to it. The first sealing member 22 is circumferentially disposed between the pole post 21 and the second metal member 12. The current collector 24 is connected to one end of the pole post 21. The second sealing member 13 is circumferentially disposed on the pole post 21. Both ends of the second sealing member 13 are connected to the first metal member 11 and the current collector 24, respectively.

[0042] It is understood that the second seal 13 has a first connecting surface 131 facing the first metal member 11, which is connected to the first metal member 11. The second seal 13 has a second connecting surface 132 facing the manifold 24, which is connected to the manifold 24.

[0043] When applied to cylindrical cells, both the first metal part 11 and the second metal part 12 are annular. When applied to prismatic cells, the outer periphery of the first metal part 11 is rectangular and the inner periphery is circular, and the second metal part 12 is annular.

[0044] It is understood that the first metal part 11 and the second metal part 12 are both made of metal, but the materials are different. For example, the first metal part 11 is aluminum, and the second metal part 12 is stainless steel.

[0045] It is understandable that the material density of the first metal part 11 is lower than that of the second metal part 12.

[0046] It is understood that the first seal 22 seals the second metal part 12 to the pole post 21. When the first seal 22 is a rigid seal, the melting point of the material of the second metal part 12 is higher than that of the material of the rigid seal. For example, the material of the rigid seal is glass, and the material of the second metal part 12 is stainless steel.

[0047] For example, the first seal 22 is a rigid seal, such as glass.

[0048] It is understood that the connection between the first metal part 11 and the second metal part 12 can be achieved through methods such as sealant or welding. When using sealant, an adhesive layer is provided between the first metal part 11 and the second metal part 12. When using welding, solder can be provided between the first metal part 11 and the second metal part 12.

[0049] It is understood that the connection between the second seal 13 and the first metal part 11 and the manifold 24 can be either abutment or adhesive bonding. Specifically, when the second seal 13 is a rubber ring, the second seal 13 abuts against the first metal part 11 and the manifold 24. When the second seal 13 is a sealant, the second seal 13 is adhesively bonded to the first metal part 11 and the manifold 24.

[0050] In this embodiment, by providing a second sealing element 13 between the first metal component 11 and the current collector 24, electrolyte can be effectively prevented from flowing from the mating portion between the first metal component 11 and the electrode post 21 into the space between the first metal component 11 and the second metal component 12. This avoids galvanic corrosion between the first metal component 11 and the second metal component 12, helps ensure the structural strength of the first metal component 11 and the second metal component 12, and thus improves the structural strength of the cover plate assembly 200.

[0051] Furthermore, by placing the second seal 13 between the first metal part 11 and the current collector 24, the gap between the first metal part 11 and the current collector 24 can be effectively utilized, thereby avoiding the need to adjust the position of other components or affect the height of the cover assembly 200 due to the placement of the second seal 13. This simplifies the design of the cover assembly 200 and ensures the energy density of the battery cell 300.

[0052] Furthermore, by positioning the second metal component 12 on one side of the axial direction of the first metal component 11, the first metal component 11 can be either insulated from the pole post 21 or electrically connected to it, depending on actual needs. Correspondingly, the first metal component 11 and the second metal component 12 can be connected by insulating adhesive for insulation, or electrically connected by welding or other methods. This allows the polarities of the first metal component 11 and the second metal component 12 to be the same or opposite.

[0053] Please see Figure 2 In some embodiments, along the axial direction of the pole post 21, the second seal 13 has a height dimension H1 that satisfies: 0.3mm≤H1≤3mm.

[0054] It is understood that the height dimension H1 of the second seal 13 includes, but is not limited to, 0.3mm, 0.31mm, 0.44mm, 0.52mm, 0.67mm, 0.78mm, 0.83mm, 0.95mm, 1.04mm, 1.12mm, 1.26mm, 1.33mm, 1.47mm, 1.55mm, 1.61mm, 1.68mm, 1.74mm, 1.82mm, 1.93mm, 2.06mm, 2.11mm, 2.23mm, 2.34mm, 2.45mm, 2.52mm, 2.63mm, 2.71mm, 2.86mm, 2.92mm, 2.97mm, 2.99mm, and 3mm.

[0055] In this embodiment, by limiting the height dimension H1 of the second seal 13, the second seal 13 can have a sufficient height dimension H1 to meet the sealing requirements between the first metal part 11 and the pole post 21, and the height dimension occupied by the second seal 13 can be controlled to avoid the second seal 13 occupying a large height dimension that would affect the arrangement of the first metal part 11 and the current collector 24.

[0056] Furthermore, when the distance between the first metal part 11 and the current collector 24 is constant, and when the second seal 13 is a rubber ring, by controlling the height dimension H1 of the second seal 13, the second seal 13 can be prevented from being subjected to excessive pressure, which is beneficial to improving the service life of the second seal 13.

[0057] Please see Figure 2 In some embodiments, the second seal 13 has a thickness dimension D1 along the radial direction of the pole post 21, satisfying: 0.3mm≤D1≤6mm.

[0058] It is understood that the thickness D1 of the second seal 13 includes, but is not limited to, 0.3mm, 0.31mm, 0.47mm, 0.63mm, 0.82mm, 1.05mm, 1.23mm, 1.44mm, 1.61mm, 1.78mm, 1.92mm, 2.13mm, 2.35mm, 2.54mm, 2.71mm, 2.88mm, 3.06mm, 3.22mm, 3.44mm, 3.65mm, 3.81mm, 3.99mm, 4.17mm, 4.33mm, 4.56mm, 4.72mm, 4.91mm, 5.14mm, 5.33mm, 5.56mm, 5.89mm, and 6mm.

[0059] It is understandable that the outer diameter of the second seal 13 is not greater than the inner diameter of the lower plastic part of the cover plate assembly 200.

[0060] In this embodiment, by limiting the thickness D1 of the second seal 13, the second seal 13 can have a sufficient thickness D1 to meet the sealing requirements between the first metal part 11 and the pole post 21, and the thickness D1 of the second seal 13 can be controlled to avoid the second seal 13 being too thick and causing unnecessary material increase. This allows control over the material usage of the second seal 13 and helps control the cost of the cover plate assembly 200.

[0061] In some embodiments, the second seal 13 is an elastic rubber ring. In the axial direction of the pole post 21, the two ends of the second seal 13 abut against the first metal part 11 and the current collector 24 respectively, and the second seal 13 is in a compressed state.

[0062] Among them, the installation and removal of the elastic rubber ring are relatively easy, and the sealing installation can be completed quickly, improving work efficiency.

[0063] In some other embodiments, the second seal 13 is a sealant, and the two ends of the second seal 13 are respectively bonded to the first metal part 11 and the manifold 24.

[0064] Among them, the sealant has good filling properties, which can fill gaps of various shapes and sizes, and can effectively fill tiny unevenness, ensuring the integrity of the seal.

[0065] In some embodiments, the inner circumferential surface of the second seal 13 is bonded to the outer circumferential surface of the electrode post 21. This increases the connection area between the second seal 13 and adjacent components, thereby increasing the sealing surface used to block electrolyte flow, such as between the first metal component 11 and the second metal component 12. This effectively prevents galvanic corrosion between the first metal component 11 and the second metal component 12, thus ensuring the structural strength of the first metal component 11 and the second metal component 12.

[0066] Please see Figure 1 , Figure 3 as well as Figure 4 , Figure 3 This is a structural schematic of the first metal part 11 provided in the embodiments of this application. Figure 4 This is the structural intent of the second metal member 12 provided in the embodiments of this application. In some embodiments, a recessed platform 111 is provided on the side of the first metal member 11 facing away from the current collector 24. The second metal member 12 is disposed in the recessed platform 111. In this way, the mating surface between the first metal member 11 and the second metal member 12 can be increased to improve the structural stability of the cover assembly 200, and the second metal member 12 can be quickly positioned by the recessed platform 111 to improve the assembly efficiency between the first metal member 11 and the second metal member 12, thereby improving the manufacturing efficiency of the cover assembly 200.

[0067] Please see Figure 1 , Figure 3 as well as Figure 4 In some embodiments, a mating hole 112 is provided at the bottom of the recessed platform 111. An extension section 121 protrudes from the side of the second metal member 12 facing the bottom of the recessed platform 111. Both the extension section 121 and one end of the first sealing member 22 extend into the mating hole 112. This increases the mating surface area between the first metal member 11 and the second metal member 12, thereby improving the structural stability of the cover plate assembly 200. It also allows the second metal member 12 to have a larger mating area with the first sealing member 22, thus improving the sealing performance between the second metal member 12 and the pole post 21.

[0068] Please see Figure 1 In some embodiments, the cover plate assembly 200 further includes a first insulating member 23, which is sleeved on the pole post 21 and located on the side of the first metal member 11 facing the current collector 24.

[0069] It can be understood that the first insulating component 23 can also be called the lower plastic component, which insulates and isolates the first metal component 11 and the second metal component 12 from the electrode assembly 32.

[0070] Please see Figure 2 In some embodiments, the inner circumferential side of the first insulating member 23 is spaced apart from the current collector 24. This allows for a smaller thickness of the first insulating member 23, thereby reducing its weight and consequently the weight of the battery cell 300.

[0071] For example, the thickness of the first insulating member 23 is 0.4 mm to 0.6 mm.

[0072] In some embodiments, the first metal part 11 is made of aluminum, and the second metal part 12 is made of stainless steel. This allows the first metal part 11 to have a lower weight, while the second metal part 12 has a higher melting point, ensuring that the second metal part 12 does not melt when fused with a rigid seal such as glass.

[0073] In some embodiments, the first seal 22 is a glass seal. This avoids problems such as rubber aging and seal failure that can occur when using rubber seals.

[0074] Please see Figure 5 , Figure 5 This is a schematic diagram of the structure of the battery cell 300 provided in an embodiment of this application. In a second aspect, an embodiment of this application provides a battery cell 300. The battery cell 300 includes a housing 31, an electrode assembly 32, and the aforementioned cover plate assembly 200. The housing 31 has a receiving cavity 33. The electrode assembly 32 is disposed within the receiving cavity 33. The outer periphery of a first metal member 11 is connected to the housing 31. A current collector 24 is connected to the electrode assembly 32.

[0075] It is understood that the electrode assembly 32 includes a positive electrode, a separator, and a negative electrode arranged sequentially. In a cylindrical battery, the positive electrode, separator, and negative electrode are stacked and wound sequentially to form a core. The positive electrode is electrically connected to the current collector 24. The negative electrode is electrically connected to the casing 31.

[0076] It is understood that the battery cell 300 includes the aforementioned cover plate assembly 200, and the battery cell 300 has all the beneficial effects of the aforementioned cover plate assembly 200, which will not be repeated here in this embodiment.

[0077] It is understood that in the embodiments of this application, the path for the electrolyte to penetrate from the outer periphery of the first metal part 11 into the mating area between the first metal part 11 and the second metal part 12 is relatively long, and the possibility of electrolyte penetration from the outer periphery of the first metal part 11 is small due to the adhesion between the first insulating part 23 and the first metal part 11. Therefore, the embodiments of this application mainly consider electrolyte isolation around the electrode post 21. Of course, depending on the actual situation, an electrolyte isolation structure, such as a sealant, can also be provided between the first metal part 11 and the first insulating part 23 on the side away from the electrode post 21. The sealant bonds the opposing surfaces of the first metal part 11 and the first insulating part 23.

[0078] Please see Figure 6 , Figure 6 This is a schematic diagram of a battery pack 400 provided in an embodiment of this application. In a third aspect, an embodiment of this application provides a battery pack 400, which includes the aforementioned battery cells 300. Multiple battery cells 300 are electrically connected.

[0079] It is understood that the battery pack 400 may also include a housing 41 and a cover 42, which are fitted together to form an installation cavity 43, and the battery cell 300 is disposed in the installation cavity 43.

[0080] It is understood that the battery pack 400 includes the aforementioned battery cell 300, and the battery pack 400 has all the beneficial effects of the aforementioned battery cell 300, which will not be repeated here in this embodiment.

[0081] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A cover plate assembly (200) characterized by, include: pole (21); A first metal component (11) is arranged in a ring around the pole post (21); The second metal part (12) is arranged around the pole post (21) along the axial direction of the pole post (21). The second metal part (12) is located on one side of the first metal part (11) and is connected to the first metal part (11). The first sealing element (22) is arranged in a ring between the pole post (21) and the second metal element (12); The current collector (24) is connected to one end of the pole (21); as well as The second sealing element (13) is arranged around the pole post (21), and the two ends of the second sealing element (13) are respectively connected to the first metal part (11) and the current collector (24).

2. The cover plate assembly (200) according to claim 1, characterized in that Along the axial direction of the pole post (21), the second seal (13) has a height dimension H1 that satisfies: 0.3mm≤H1≤3mm.

3. The cover plate assembly (200) of claim 1, wherein, Along the radial direction of the pole post (21), the second seal (13) has a thickness dimension D1, which satisfies: 0.3mm≤D1≤6mm.

4. The cover plate assembly (200) of claim 1, wherein, The second seal (13) is an elastic rubber ring. On the axial direction of the pole post (21), the two ends of the second seal (13) abut against the first metal part (11) and the current collector (24) respectively, and the second seal (13) is in a compressed state.

5. The cover plate assembly (200) of claim 1, wherein, The second seal (13) is a sealant, and the two ends of the second seal (13) are respectively bonded to the first metal part (11) and the current collector (24).

6. The cover plate assembly (200) of claim 5, wherein, The inner circumferential surface of the second seal (13) is bonded to the outer circumferential surface of the pole post (21).

7. The cover plate assembly (200) according to any one of claims 1-6, characterized in that, The first metal part (11) has a recessed platform (111) on the side away from the current collector (24), and the second metal part (12) is disposed in the recessed platform (111).

8. The cover plate assembly (200) of claim 7, wherein, A mating hole (112) is provided at the bottom of the recessed platform (111), and an extension section (121) protrudes from the side of the second metal part (12) facing the bottom of the recessed platform (111). One end of the extension section (121) and one end of the first sealing member (22) both extend into the mating hole (112).

9. The cover plate assembly (200) according to any one of claims 1-6, characterized in that, The cover plate assembly (200) further includes a first insulating member (23), which is sleeved on the pole post (21) and located on the side of the first metal member (11) facing the current collector (24).

10. The cover plate assembly (200) of claim 9, wherein, The inner circumferential side of the first insulating member (23) is spaced apart from the current collector (24).

11. The cover plate assembly (200) according to any one of claims 1-6, characterized in that, The material of the first metal part (11) includes aluminum, and the material of the second metal part (12) includes stainless steel; and / or, The first sealing element (22) is a glass sealing element.

12. An electric cell (300) characterized by include: The housing (31) has a receiving cavity (33); An electrode assembly (32) is disposed within the receiving cavity (33); as well as In the cover plate assembly (200) as described in any one of claims 1-11, the outer periphery of the first metal part (11) is connected to the housing (31), and the current collector (24) is connected to the electrode assembly (32).

13. A battery pack (400), characterized by The battery cell (300) as claimed in claim 12, wherein a plurality of the battery cell (300) are provided and the plurality of the battery cell (300) are electrically connected.

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