Top cover assembly, manufacturing method thereof and power battery

Abstract

The application provides a top cover assembly, a manufacturing method thereof and a power battery. The first connecting part and the second connecting part which can be connected with an external circuit or a busbar are arranged on the pole block, and the first fusing part and the second fusing part are arranged for the first connecting part and the second connecting part respectively. The cross-sectional area of the first fusing part is not less than that of the second fusing part, that is, the second fusing part is more easily fused than the first fusing part. The user can connect the external circuit or the busbar on the second connecting part first. When the current is too large, the second fusing part is fused. Then, the user can connect the external circuit or the busbar on the first connecting part again, and the first fusing part can also protect the pole or the power battery. On the basis of ensuring the safety of the top cover assembly, the service life and the reliability of the top cover assembly are further improved, and the maintainability of the top cover assembly is good.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power batteries, in particular to a top cover assembly, a manufacturing method thereof and a power battery. BACKGROUND

[0002] With the increasing maturity of lithium ion battery technology, lithium ion batteries are widely used as power batteries in electric vehicles and energy storage fields, and the use performance and safety of lithium ion batteries are increasingly required. In order to improve the safety of power batteries, a fuse structure is usually provided on the power battery, which melts when the power battery is overcharged or the like, preventing the power battery from exploding or the like.

[0003] In the prior art, the power battery can be connected to an external circuit or a busbar to connect more power batteries in parallel, etc. In order to protect the power battery, a fuse structure is usually provided on the pole block of the top cover of the power battery.

[0004] However, the service life of the external pole block fuse structure is limited; when a large number of power batteries are connected through the busbar, the melting of one fuse structure can easily cause more power batteries to be disconnected, and the power battery after the failure of the fuse structure is inconvenient to replace, and the reliability and maintainability of the power battery are poor. SUMMARY

[0005] The present application provides a top cover assembly, a manufacturing method thereof and a power battery to solve the technical problem of poor maintainability of the top cover assembly in the prior art.

[0006] In one aspect, the present application provides a top cover assembly, comprising:

[0007] a pole, a pole block, an upper plastic, and a cover plate provided with a pole hole;

[0008] The pole is arranged in the pole hole and connected with the pole block, the pole block is arranged on one side of the cover plate, and the upper plastic is arranged between the upper pole and the cover plate;

[0009] The pole block comprises a first connecting portion with a first fuse portion, a second connecting portion with a second fuse portion, and a pole body;

[0010] The pole body is connected with the pole, the first connecting portion is connected with the pole body through the first fuse portion, the second connecting portion is connected with the first connecting portion or the pole body through the second fuse portion, and the cross-sectional area of the first fuse portion is not less than that of the second fuse portion.

[0011] In one possible implementation of the present application, the first connecting portion is arranged around the pole body, the first fuse portion is in the form of a circular ring, and the second connecting portion is connected with the first connecting portion through the second fuse portion.

[0012] In a possible implementation of the present application, the first fusing portion includes a through-hole segment and a connecting segment.

[0013] In a possible implementation of the present application, the first fusing portion includes a plurality of spaced-apart connecting segments.

[0014] In a possible implementation of the present application, the connecting segment includes a first area and a second area, and a cross-sectional area of the first area is not less than that of the second area.

[0015] In a possible implementation of the present application, the second connecting portion connects the pole body through the second fusing portion.

[0016] In a possible implementation of the present application, the first fusing portion and / or the second fusing portion has a notch.

[0017] In a possible implementation of the present application, in the orthographic projection on the plane where the cover plate is located, an area of the first connecting portion is not greater than that of the second connecting portion.

[0018] In another aspect, the present application also provides a power battery including the top cover assembly as described above.

[0019] In another aspect, the present application also provides a manufacturing method of a top cover assembly, including:

[0020] encapsulating the pole block with a pole body, and forming an upper plastic on the surface of the pole block;

[0021] providing a cover plate with a pole column hole in which a pole column is arranged;

[0022] fixedly connecting the pole block and the cover plate, wherein the pole body is sleeved on the pole column.

[0023] This application provides a top cover assembly, its manufacturing method, and a power battery, comprising: a terminal post, an electrode block, an upper plastic layer, and a cover plate with a terminal post hole; the terminal post is disposed within the terminal post hole; the electrode block is disposed on one side of the cover plate, the electrode block comprising an electrode body, a first connecting portion having a first fusible portion, and a second connecting portion having a second fusible portion; the electrode body is connected to the terminal post, the first connecting portion is connected to the electrode body through the first fusible portion, and the second connecting portion is connected to the first connecting portion or the electrode body through the second fusible portion, wherein the cross-sectional area of ​​the first fusible portion is not less than the cross-sectional area of ​​the second fusible portion; the upper plastic layer is disposed between the electrode block and the cover plate. By providing the first connecting portion and the second connecting portion on the electrode block for connection to external circuits or buses, and by providing the first fusible portion and the second fusible portion respectively to the first connecting portion and the second connecting portion; wherein the cross-sectional area of ​​the first fusible portion is not less than the cross-sectional area of ​​the second fusible portion, i.e., the second fusible portion is easier to melt than the first fusible portion. The user can first connect an external circuit or busbar to the second connection part; when the current is too high, the second fuse will blow. Then, the user can reconnect the external circuit or busbar to the first connection part, and the first fuse can also protect the terminal post or the power battery, etc.; while ensuring the safety of the top cover assembly, the service life and reliability of the top cover assembly are further improved, and the top cover assembly has good maintainability. Attached Figure Description

[0024] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0025] Figure 1 This is a schematic diagram of the structure of the top cover assembly provided in an embodiment of this application;

[0026] Figure 2 An exploded view of the top cover assembly provided in an embodiment of this application;

[0027] Figure 3 for Figure 2 Enlarged view of point E in the middle;

[0028] Figure 4 A top view of the pole block provided in an embodiment of this application;

[0029] Figure 5 for Figure 4 Sectional view at point D;

[0030] Figure 6 for Figure 5 Enlarged view of point K;

[0031] Figure 7 Another top view of the pole block provided in an embodiment of this application;

[0032] Figure 8 for Figure 7 Sectional view at point F;

[0033] Figure 9 for Figure 8 Enlarged view of point H in the middle;

[0034] Figure 10 The process steps for manufacturing the top cover assembly provided in the embodiments of this application.

[0035] Figure label:

[0036] Top cover assembly 100, electrode post 200, positive electrode post 210, negative electrode post 220, electrode block 300, first connecting part 310, second connecting part 320, first fuse part 330, through hole section 331, connecting section 332, second fuse part 340, electrode body 350, notch 360, upper plastic 400, cover plate 500, electrode post hole 510, liquid injection hole 520, sealing ring 600, lower plastic 700, flip plate 800, explosion-proof plate 900. 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 them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0038] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0039] In the description of the application, it is necessary to point out that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "linking" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection or can communicate with each other; it can be directly connected, or indirectly connected through intermediate medium, it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0040] In the present application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "under", "below" and "under" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0041] The following disclosure provides many different embodiments or examples for implementing different structures of the application. In order to simplify the disclosure of the application, the components and arrangements of specific examples are described in the following. Of course, they are only examples, and the purpose is not to limit the application. In addition, the application can repeatedly refer to the same reference numerals and / or reference letters in different examples. Such repetition is for the purpose of simplification and clarity, and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, the application provides examples of various specific processes and materials, but those skilled in the art can realize the application of other processes and / or the use of other materials.

[0042] Please refer to Figures 1 to 6The embodiment of the present application provides a top cover assembly 100, which comprises a pole 200, a pole block 300, an upper plastic 400 and a cover plate 500 provided with a pole hole 510; the pole is arranged in the pole hole; the pole block 300 is arranged on one side of the cover plate 500, and the pole block 300 comprises a pole body 350, a first connecting part 310 provided with a first fusing part 330 and a second connecting part 320 provided with a second fusing part 340; the pole body 350 is connected with the pole 200, the first connecting part 310 is connected with the pole body 350 through the first fusing part 330, the second connecting part 320 is connected with the first connecting part 310 or the pole body 350 through the second fusing part 340, the cross-sectional area of the first fusing part 330 is not less than that of the second fusing part 340; and the upper plastic 400 is arranged between the pole block 300 and the cover plate 500.

[0043] It should be noted that when current flows through a conductor, the conductor will heat up because the conductor has a certain resistance. It is known that the greater the current in the conductor, the greater the heat generated by the conductor; and as a large current passes through the conductor for a long time, the heat generated by the conductor accumulates, thereby causing the conductor to heat up; finally, when the temperature of the conductor reaches the melting point temperature of the material itself, the conductor will be fused, thereby cutting off the circuit.

[0044] In addition, the heating speed of the conductor is also related to the specific heat capacity and mass of the conductor itself. For example, in the embodiment of the present application, the cross-sectional area of the first connecting part 310 or the second connecting part 320 is greater than that of the first fusing part 330 and the second fusing part 340. In the case of the same unit length and the same material composition, that is, the specific heat capacity of each part of the pole block 300 is consistent, the mass of the first connecting part 310 or the second connecting part 320 is greater than that of the first fusing part 330 and the second fusing part 340; therefore, the heating speed of the first fusing part 330 and the second fusing part 340 is much greater than that of the first connecting part 310 or the second connecting part 320 when the current passes through the pole block 300 in the same time. Therefore, when a large current passes through the pole block 300, the first fusing part 330 and the second fusing part 340 are more likely to be fused than the first connecting part 310 or the second connecting part 320. In addition, the cross-sectional area of the first fusing part 330 is not less than that of the second fusing part 340, that is, the first fusing part 330 is thicker than the second fusing part 340, and the second fusing part 340 is more likely to be fused than the first fusing part 330.

[0045] It should be noted that the top cover assembly 100 provided by the embodiment of the present application can be used in a square shell power battery (not shown in the figure). The top cover assembly 100 is mounted on the shell, and the pole block 300 is arranged on the side of the cover plate 500 away from the shell, that is, the first connecting part 310 and the second connecting part 320 are exposed on the outside of the power battery, which can be used to connect external circuits or busbars to connect more power batteries and the like.

[0046] By arranging the first connecting part 310 and the second connecting part 320 which can be connected to external circuits or busbars and the like on the pole block 300, and arranging the first fusing part 330 and the second fusing part 340 for the first connecting part 310 and the second connecting part 320 respectively, the cross-sectional area of the first fusing part 330 is not less than that of the second fusing part 340, that is, the second fusing part 340 is more likely to be fused than the first fusing part 330. The user can first connect the external circuits or busbars to the second connecting part 320, and when the current is too large, the second fusing part 340 is fused. Then, the user can again connect the external circuits or busbars and the like to the first connecting part 310, and the first fusing part 330 can also protect the pole 200 or the power battery and the like; on the basis of ensuring the safety of the top cover assembly 100, the service life of the top cover assembly 100 is further improved.

[0047] Specifically, the upper plastic 400 is formed by injection molding, which avoids the electrical connection between the pole block 300 and the cover plate 500, ensures the safety and reliability of the top cover assembly 100, and the maintainability of the top cover assembly 100 is good.

[0048] Specifically, the cross-sectional areas of the second fusing part 340 and the first fusing part 330 are 0.5mm 2 -10mm 2 .

[0049] Specifically, the pole block 300 connected to the pole 200 can be a positive pole 210.

[0050] In some embodiments, the first connecting part 310 is arranged around the pole body 350, the first fusing part 330 is in the form of a circular ring, and the second connecting part 320 is connected to the first connecting part 310 through the second fusing part 340.

[0051] It should be noted that the pole 200 is usually in the form of a cylinder, and the pole body 350 is sleeved on the pole 200, thereby fixedly connecting the pole block 300 and the pole 200.

[0052] The first fusing part 330 is arranged in a circular ring shape matching the pole body 350, and the circular structure of the first fusing part 330 has good pressure bearing capacity, which can improve the structural strength of the pole block 300.

[0053] The second connecting part 320 is connected to the first connecting part 310 through the second fusing part 340, and is connected to the pole body 350 through the first fusing part 330, that is, the second connecting part 320, the first connecting part 310 and the pole body 350 are connected in series. The second fusing part 340 is more likely to be fused than the first fusing part 330. When the second connecting part 320 is first connected to an external circuit or a busbar, the second connecting part 320 will first be disconnected from the pole 200 due to excessive current. Then the first connecting part 310 is connected to the external circuit or the busbar, and the first connecting part 310 will be disconnected from the pole 200 due to excessive current. This improves the reliability of the multiplexing of the pole block 300.

[0054] In some embodiments, the first fusing part 330 includes a through hole section 331 and a connecting section 332.

[0055] As can be seen from the above, the temperature rise speed of the first fusing part 330 is related to its specific heat capacity and mass. When the first fusing part 330 includes a through hole section 331 and a connecting section 332, that is, the pole body 350 and the first connecting part 310 have through holes, that is, the arc length of the first fusing part 330 is less than the length of the pole body 350. On the basis that the first fusing part 330 does not fuse under the same current, the thickness of the first fusing part 330, that is, the cross-sectional area, can be increased. This further improves the connection strength of the pole body 350 and the first connecting part 310, and prolongs the service life of the pole block 300.

[0056] In some embodiments, the first fusing part 330 includes a plurality of spaced connecting sections 332.

[0057] Preferably, the first fusing part 330 includes four connecting sections 332.

[0058] By arranging four connecting sections 332 on the first fusing part 330, that is, four through hole sections 331 are arranged on the first fusing part 330, and the pole body 350 and the first connecting part 310 have four thick connecting sections 332, the stress and current of the first connecting part 310 can be uniformly conducted to the pole body 350, which improves the structural strength of the pole block 300.

[0059] Further, in some embodiments, the first fusing portion 330 can further include three connection segments 332, or five connection segments 332, without being limited thereto.

[0060] Preferably, the plurality of connection segments 332 are symmetrically arranged.

[0061] The symmetrically arranged connection segments 332 can improve the structural stability of the pole piece 300.

[0062] Further, in some embodiments, the plurality of connection segments 332 can also be asymmetrically arranged, without being limited thereto.

[0063] Preferably, the upper plastic portion 400 is filled in the through-hole segment 331; and the portion of the upper plastic portion 400 filled in the through-hole segment 331 does not extend to the outside of the through-hole segment 331, i.e., the surface of the through-hole segment 331 is smooth, thereby improving the surface flatness of the top cover assembly.

[0064] In some embodiments, the arc length of the through-hole segment 331 is A, and the arc length of the connection segment 332 is B, wherein A and B satisfy: 0.5A≤B≤2A.

[0065] In this way, the structure of the pole piece 300 is more stable.

[0066] Further, in some embodiments, A and B can also satisfy: 0.3A≤B<0.5A, or 2A<B≤3A, without being limited thereto.

[0067] In some embodiments, the connection segment 332 includes a first area (not shown in the figure) and a second area (not shown in the figure), and the cross-sectional area of the first area is not less than that of the second area.

[0068] It can be understood that the cross-sectional area of the first area is not less than that of the second area, and the second area is more likely to be fused than the first area.

[0069] When the first connection portion 310 is connected to an external circuit or a busbar, the first fusing portion 330 will first fuse from the second area and then fuse the first area; the fusing of the first fusing portion 330 is more stable and orderly, which can reduce the generation of fusing impurities, and the fusing surface of the first fusing portion 330 is more regular, which is convenient for maintenance personnel to remove the pole piece 300 for maintenance of the top cover assembly 100.

[0070] Please refer to Figures 1 to 3 , Figures 7 to 9 In some embodiments, the second connection portion 320 is connected to the pole body 350 through the second fusing portion 340.

[0071] That is, the second connecting portion 320 is not connected to the first connecting portion 310, and the first connecting portion 310 is in parallel with the second connecting portion 320. A large current can not melt the first fusing portion 330 and the second fusing portion 340 at one time, and the reusability of the pole piece 300 is improved.

[0072] In some embodiments, the second fusing portion 340 is detachably connected to the first connecting portion 310 or the pole body 350.

[0073] It can be understood that, since the second fusing portion 340 is more likely to be melted than the first fusing portion 330, a user can first connect the second connecting portion 320 to an external circuit or a busbar, etc. When the second fusing portion 340 is melted, the melted second fusing portion 340 is detached and replaced with a new second fusing portion 340, and the second connecting portion 320 can still be used. The user can avoid transferring the external circuit or the busbar, etc. to the first connecting portion 310, and the first connecting portion 310 is used as a backup connecting portion, and the reliability of the pole piece 300 is improved.

[0074] Further, in other embodiments, the second fusing portion 340 can also be fixedly connected to the first connecting portion 310 or the pole body 350, for example, by welding, bonding, etc., which is not limited here.

[0075] In some embodiments, the first fusing portion 330 and / or the second fusing portion 340 has a notch 360.

[0076] By providing the notch 360, the first fusing portion 330 and the second fusing portion 340 are more likely to be melted at the position of the notch 360, and the controllability of melting of the first fusing portion 330 and the second fusing portion 340 can be improved.

[0077] In some embodiments, in the orthographic projection on the plane where the cover plate 500 is located, the area of the first connecting portion 310 is not greater than the area of the second connecting portion 320.

[0078] It can be understood that, since the external circuit or the busbar, etc. is first connected to the second connecting portion 320, the first connecting portion 310 is used as a backup connecting portion, and the surface utilization rate of the pole piece 300 can be improved. Since the surface area of the first connecting portion 310 is not greater than the surface area of the second connecting portion 320, the user can distinguish them, and the second fusing portion 340 cannot be used when the first connecting portion 310 and the second connecting portion 320 are connected in series, and the user mistakenly connects the external circuit or the busbar, etc. to the first connecting portion 310, thereby prolonging the service life of the pole piece 300.

[0079] Please refer to Figures 1 to 3 In some embodiments, the top cover assembly 100 further comprises a negative pole 220, or a sealing ring 600, or a lower plastic 700, or a liquid injection hole 520, or a flip piece 800, or an explosion-proof piece 900, and the like, and users can select appropriate components according to actual needs, and no more limitations are made herein.

[0080] Please refer to Figure 10 The application also provides a power battery comprising the top cover assembly 100. Since the power battery has the above-mentioned top cover assembly 100, it has all the same beneficial effects, and the application will not be described again herein.

[0081] On the other hand, the application also provides a manufacturing method of the top cover assembly 100, comprising:

[0082] The pole block 300 with the pole body 350 is encapsulated, and the upper plastic 400 is formed on the surface of the pole block 300;

[0083] The cover plate 500 provided with the pole 200 in the pole hole 510 is provided;

[0084] The pole block 300 and the cover plate 500 are fixedly connected, and the pole body 350 is sleeved on the pole 200.

[0085] Specifically, the pole body 350 is encapsulated by using the encapsulation process to form the upper plastic 400, which can simplify the preparation steps of the top cover assembly 100; and the upper surface of the upper plastic 400 away from the cover plate 500 is flush with the upper surface of the pole block 300, which can improve the surface flatness of the top cover assembly 100.

[0086] Optionally, the pole 200 can be riveted into the pole body 350 by a riveting process, and the pole 200 and the pole block 300 can be welded together by laser welding; the riveting and laser welding fixing mode can improve the connection strength of the pole 200 and the pole body 350.

[0087] Further, in other embodiments, the pole directly matched with the pole body can be inserted into the pole body, and then the pole and the pole body can be directly laser welded; the manufacturing steps of the top cover assembly can be simplified.

[0088] Further, in other embodiments, ultrasonic welding and other welding processes can be used, and no more limitations are made herein.

[0089] In the above embodiments, the description of each embodiment has its own focus, and the parts not described in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0090] The top cover assembly, the manufacturing method thereof and the power battery provided by the embodiments of the present application are described in detail above, and the principles and implementation manners of the present application are described by applying specific examples in this paper. The above embodiment descriptions are only used to help understand the technical solutions and the core ideas of the present application. Those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can still be modified, or some technical features can be replaced equivalently. The modifications or replacements do not change the essence of the corresponding technical solutions out of the scope of the technical solutions of the embodiments of the present application.

Claims

1. A cap assembly, characterized by, The top cover assembly is mounted to a battery case, comprising: a pole, a pole block, an upper plastic, and a cover plate provided with a pole hole; the pole is arranged in the pole hole; the pole block is arranged on the side of the cover plate away from the case, the pole block comprises a pole body, a first connecting part provided with a first fusing part, and a second connecting part provided with a second fusing part; the pole body is connected to the pole, the first connecting part is connected to the pole body through the first fusing part, the second connecting part is connected to the first connecting part or the pole body through the second fusing part, the cross-sectional area of the first fusing part is not less than that of the second fusing part, and the second fusing part fuses earlier than the first fusing part; the upper plastic is arranged between the pole block and the cover plate.

2. The cap assembly of claim 1, wherein, The first connecting part is arranged around the pole body, the first fusing part is in the shape of a ring, and the second connecting part is connected to the first connecting part through the second fusing part.

3. The cap assembly of claim 2, wherein, The first fusing part comprises a through hole section and a connecting section.

4. The cap assembly of claim 3, wherein, The first fusing part comprises a plurality of spaced connecting sections.

5. The cap assembly of claim 3, wherein The connecting section comprises a first area and a second area, and the cross-sectional area of the first area is not less than that of the second area.

6. The cap assembly of claim 1, wherein, The second connecting part is connected to the pole body through the second fusing part.

7. A cap assembly as claimed in any one of claims 1 to 6, wherein, The first fusing part and / or the second fusing part has a notch.

8. A cap assembly as claimed in any one of claims 1 to 6, wherein, In the orthographic projection on the plane of the cover plate, the area of the first connecting part is not greater than that of the second connecting part.

9. A power cell, characterized by The top cover assembly of any one of claims 1-8.

10. A method of manufacturing a roof assembly, characterized by A manufacturing method for manufacturing the top cover assembly of any one of claims 1-8, the manufacturing method comprising: encapsulating the pole block with the pole body and forming the upper plastic on the surface of the pole block; providing the cover plate provided with the pole hole and the pole arranged in the pole hole; fixedly connecting the pole block and the cover plate, wherein the pole body is sleeved on the pole.

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