Secondary battery top cover and secondary battery

Abstract

The utility model provides a top cover of a secondary battery. The top cover of the secondary battery comprises a pole, a top cover and a top cover, wherein the pole is provided with a pole main body part and a pole positioning part which protrudes in the horizontal direction relative to the pole main body part; the top cover plate is provided with a top cover plate main body part and a vertical protruding part protruding from the top cover plate main body part in the vertical direction; the fixing component is arranged above the vertical protruding part; the fixing component comprises a connecting part and a blocking part, the blocking part is located above the pole positioning part, the blocking part protrudes relative to the connecting part in the horizontal direction, and the cross section of the fixing component is L-shaped. The fixing component of the secondary battery disclosed by the utility model is of a special-shaped structure, so that the welding stability of the fixing component on the top cover can be improved, the positioning accuracy in the welding process is enhanced, and the air tightness and the safety performance of the battery top cover can be integrally improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a secondary battery top cover and a secondary battery. Background Technology

[0002] As electric vehicles gain a larger market share, battery safety and reliability have become a key concern for consumers. As a result, most vehicle manufacturers and battery manufacturers are working to improve battery safety and reliability.

[0003] There are three types of battery cell packaging for power lithium batteries: prismatic cells, pouch cells, and cylindrical cells. Hard-shell cells are usually assembled with an aluminum alloy shell and a top cover. The top cover is a relatively important part of hard-shell cells. Currently, there are various types of top covers for power batteries, and their reliability and economy directly determine their degree of promotion.

[0004] The airtightness of the battery top cover is crucial to battery safety. In existing technologies, the top cover is typically connected to the sealing plastic using riveting, injection molding, and welding to achieve a sealed top cover. However, welded top covers are prone to problems such as poor welding, top cover failure, and excessive welding energy affecting other assembled components, as the welding points simultaneously contribute to the sealing process. Therefore, the airtightness of welded top covers is a critical factor. To improve the sealing performance of welded top covers, existing technologies also employ rolling processes. However, rolling introduces a new problem: the supporting plastic may crack after rolling, leading to unpredictable risks and uncontrollable airtightness issues.

[0005] Therefore, in order to improve the sealing performance of the top cover, it is necessary to explore a better top cover sealing process and top cover structure in order to improve the sealing performance and safety of the top cover. Utility Model Content

[0006] To achieve a sealed and safe secondary battery top cover, this utility model provides a secondary battery top cover, comprising:

[0007] The pole post is provided with a pole post body and a pole post positioning part that protrudes horizontally relative to the pole post body;

[0008] The top cover plate has a main body and a vertical protrusion that protrudes from the main body in the vertical direction;

[0009] A fixing member is disposed above the vertical protrusion; the fixing member includes a connecting part and a blocking part, the blocking part is located above the pole positioning part, the blocking part protrudes horizontally relative to the connecting part, and the cross-sectional structure of the fixing member is L-shaped.

[0010] Furthermore, the top of the fixing member is stepped.

[0011] Furthermore, the top end of the fixing member is planar.

[0012] Furthermore, the top cover plate is also provided with pole mounting holes, and the height of the side of the fixing member near the pole mounting holes is higher than the side away from the pole mounting holes.

[0013] Furthermore, the fixing component is made of one or more types of aluminum or steel.

[0014] Furthermore, the vertical height of the connecting part is 0.1mm-5mm.

[0015] Furthermore, the height of the blocking part in the vertical direction is 0.05mm-4mm.

[0016] Furthermore, the length of the blocking part in the horizontal direction is 0.1mm-5mm.

[0017] Furthermore, the top cover plate is also provided with pole mounting holes, and the height of the fixing member on the side close to the pole mounting holes is less than that on the side away from the pole mounting holes.

[0018] On the other hand, this utility model also provides a secondary battery having the above-described structure.

[0019] The fixing component of the secondary battery of this utility model has an irregular shape, which can improve the welding stability of the fixing component on the top cover, enhance the positioning accuracy during the welding process, and improve the overall airtightness and safety performance of the battery top cover. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the manufacturing process of the battery top cover of this utility model;

[0021] Figure 2 This is a simplified view of the battery top cover according to the first embodiment of this utility model;

[0022] Figure 3 This is an exploded view of the battery top cover of the first embodiment of this utility model;

[0023] Figure 4 This is a view of the lower plastic part of the battery top cover according to the first embodiment of this utility model;

[0024] Figure 5 This is a schematic diagram of the pole post in the first embodiment of this utility model;

[0025] Figure 6This is a cross-sectional schematic diagram of the battery top cover according to the first embodiment of this utility model;

[0026] Figure 7 yes Figure 6 An enlarged schematic diagram of part K;

[0027] Figure 8 yes Figure 6 Enlarged schematic diagram of section F in the middle;

[0028] Figure 9 This is a schematic diagram of the fixing component in the first embodiment of this utility model;

[0029] Figure 10 This is a schematic diagram showing the connection between the fixing component and the vertical protrusion in the top cover in the second embodiment of this utility model;

[0030] Figure 11 This is a schematic diagram of the connection between the fixing component and the vertical protrusion in the top cover in the third embodiment of this utility model;

[0031] Figure 12 This is a schematic diagram showing the connection between the fixing component and the vertical protrusion in the top cover in the fourth embodiment of this utility model. Detailed Implementation

[0032] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0033] To facilitate the description of the structure of the battery top cover and the battery of this utility model, the arrangement direction of the positive and negative terminals in the battery top cover is set to the horizontal direction, and the installation direction of the positive terminal perpendicular to the horizontal direction is positioned as the vertical direction. Specifically, the left-right direction is positioned as the horizontal direction; and the up-down direction is positioned as the vertical direction.

[0034] like Figure 1-2 As shown, the battery top cover provided in this embodiment of the present invention includes a top cover plate 10, a lower plastic 60, an explosion-proof valve 80, an explosion-proof valve protection plate 70 disposed above the explosion-proof valve, an injection hole 90, a positive electrode post 31, a negative electrode post 32, a positive electrode sealing ring 21, a negative electrode sealing ring 22, a positive electrode upper plastic 51, a negative electrode upper plastic 52, a positive electrode fixing component 41, and a negative electrode fixing component 42.

[0035] like Figure 1As shown, the top cover plate 10 of this utility model is formed according to the following steps: S01: The top cover plate 10 is formed by stamping a through hole 1100 from a generally rectangular top cover plate main body 110, and then pressing an annular protrusion 1101 along the hole wall of the through hole 1100; subsequently, the top cover plate main body 1100 is stamped again along the inner side of the annular protrusion 1101 to form a vertical protrusion 1102 and a horizontal bearing portion 1103, thereby forming a vertical protrusion 1102 and a horizontal bearing portion 1103 on the horizontal bearing portion 1103. A first through hole 1104 and a second through hole 1105 are formed in the vertical protrusion 1102. The first through hole 1104 and the second through hole 1105 communicate to form a stepped hole that is larger at the top and smaller at the bottom. In this embodiment, the top cover plate 10 is made of aluminum, and there are two stepped holes connecting the first through hole 1104 and the second through hole 1105, which are respectively used for the positive electrode mounting hole 103 for installing the positive electrode 31 and the negative electrode mounting hole 104 for installing the negative electrode 32. In addition, the top cover plate 10 also has a liquid injection hole 101 and an explosion-proof valve mounting hole 105 formed by stamping. The shape and size of the liquid injection hole 101 and the explosion-proof valve mounting hole 105 can be designed according to actual needs, and their size and shape are not limited. In this embodiment, the top of the vertical protrusion 1102 is generally set to a flat shape, but it can also be set to a stepped shape or other shapes as needed. When it is necessary to set the top of the vertical protrusion 1102 into a stepped shape, the top of the vertical protrusion 1102 can be molded into a stepped shape again, or it can be molded into other shapes as needed.

[0036] The specific structure and manufacturing method of the battery top cover of this utility model will be described in detail below with reference to the accompanying drawings: S02: Install the terminal post into the stepped hole of the top cover plate. First, remove the formed top cover plate 10, then put the negative electrode sealing ring 22 on the lower end of the negative electrode post 32 and then assemble it into the negative electrode post mounting hole 104. In this embodiment, the negative electrode sealing ring 22 and the negative electrode post 32 can be formed as a tight fit or a clearance fit, and the connection method between the negative electrode sealing ring 22 and the negative electrode post 32 is not limited. In this embodiment, the negative electrode post 32 is set with a shape that is larger at the top and smaller at the bottom, including a lower end 320, a terminal post positioning part 321 and an upper end 322. The terminal post positioning part 311 is set to protrude from the main body of the negative electrode post in the horizontal direction. The diameter of the negative electrode post positioning part 321 is larger than the diameter of the lower end 310, and the diameter of the upper end 312 is larger than the diameter of the lower end 310. When the negative terminal 31 is installed into the stepped hole, the negative terminal positioning part 311 is located in the horizontal bearing part 1103 of the top cover and is supported by the horizontal bearing part 1103. It is also limited in the horizontal direction by the vertical protrusion 1102 of the top cover, thus allowing the negative terminal 32 to be stably installed in the stepped hole and stably supported and positioned. Although in this embodiment, it is preferred to first sleeve the negative terminal sealing ring 22 onto the lower end of the negative terminal 32 before installing it onto the top cover, alternatively, the negative terminal sealing ring can be first installed onto the first through hole 1104 on the top cover plate, and then the negative terminal 31 can be installed into the first through hole 1104. Although only the process of installing the negative terminal 32 onto the top cover plate 10 is described in detail above, the process of installing the positive terminal 31 onto the top cover plate is similar. The structures of the positive terminal 31 and the negative terminal 32 are similar, and the installation process is also similar; therefore, it will not be described again here.

[0037] S03: Weld the fixing component to the vertical protrusion. First, assemble the positive electrode fixing component 41 to the vertical protrusion 1102 of the top cover plate 10. Preferably, welding is used to weld the positive electrode fixing component 41 to the vertical protrusion 1102. Common welding methods such as through welding and seam welding can be used. The weld between the positive electrode fixing component 41 and the vertical protrusion 1102 is located on the outside of the positive electrode post 31 in the horizontal direction. The method of welding the positive electrode fixing component 42 to the corresponding vertical protrusion 1102 is similar to that of the negative electrode fixing component.

[0038] S04: The upper plastic is filled into the gaps between the fixing component, the pole, the vertical protrusion, and the horizontal bearing component to connect them into a whole. Specifically, the upper plastic 51 of the positive electrode is filled into the gaps between the vertical protrusion 1102, the positive pole 31, the positive electrode fixing component 41, and the horizontal bearing component 1103 using injection molding. The upper plastic 51 of the positive electrode can also be filled into the gaps by casting or other methods to connect the various components into a whole. The upper plastic 51 of the positive electrode can be made of one or more materials such as PPS, LCP, PEEK, and PI. The material of the upper plastic 52 of the negative electrode and the connection method of the top cover plate 10 are the same as those of the upper plastic 51 of the positive electrode.

[0039] The explosion-proof valve 80 is then welded to the top cover plate 10 and the explosion-proof valve mounting hole 105 is sealed. After the explosion-proof valve 80 is installed, the explosion-proof valve protective plate 70 is covered on the explosion-proof valve 80 to further protect the explosion-proof valve 80 and prevent the explosion-proof valve 80 from being interfered with by the outside or scratched by foreign objects.

[0040] Finally, the lower plastic 60 is installed onto the top cover plate 10. The lower plastic 60 has multiple first protrusions 601, and the bottom of the top cover plate 10 has multiple grooves (not shown) opposite to the first protrusions 601. The multiple first protrusions 601 on the lower plastic 60 are inserted into the grooves on the top cover plate 10, and the lower plastic 60 is welded to the top cover plate 10 by heat fusion. The lower plastic 60 also has a first hole 602 opposite to the injection hole 101. When electrolyte needs to be injected into the battery later, it can be injected into the battery through the channel formed by the injection hole 101 on the top cover plate and the first hole 602 on the lower plastic. Simultaneously, the lower plastic also has a negative electrode receiving hole 603 and a negative electrode receiving hole 604 to respectively accommodate the lower ends of the negative electrode post 31 and the negative electrode post 32. The lower plastic 60 of this invention is further provided with a groove 605, and a part of the negative electrode sealing ring 21 can extend into the groove 605, thereby improving the assembly stability of the sealing ring and the lower plastic.

[0041] The specific structure and function of the battery top cover in each embodiment will be described in detail below with reference to the accompanying drawings. Example 1

[0042] like Figure 6-8As shown, the top cover plate 10 in this embodiment includes a main body 110 and a vertical protrusion 1102. The vertical protrusion 1102 surrounds the negative electrode mounting hole 103. The vertical protrusion 1102 is configured to protrude upward from the main body 110 in the vertical direction by a distance A of 0.1mm-5mm. The horizontal support portion 1103 extends horizontally by a dimension D, which ranges from 0.5mm to 20mm. The horizontal support portion 1103 supports and carries the negative electrode 32. To fill the gap between the horizontal support portion 1103 and the negative electrode 32, the plastic 52 on the negative electrode and the negative electrode sealing ring 22 fill the gap to achieve a sealing effect. In this embodiment, the negative electrode sealing ring 22 partially fills the gap between the horizontal support portion 1103 and the negative electrode 32. Optionally, the negative electrode sealing ring 22 may also be configured not to fill the gap between the horizontal support portion 1103 and the negative electrode 32.

[0043] In this embodiment, the negative electrode fixing member 42 has an L-shaped cross-section, including a connecting part 420 and a blocking part 421. The connecting part 420 is connected to the vertical protrusion 1102 for fixing to the vertical protrusion 1102. The blocking part 421 is located above the negative electrode post 32 positioning part 321. The blocking part 421 and the post positioning part 321 overlap vertically, while the connecting part 420 does not overlap with the post positioning part 321. Furthermore, in the horizontal direction, the connecting part 420 is located outside the negative electrode post 421. The vertical height A of the connecting part 420 is 0.1mm-5mm to ensure the strength of the blocking part and prevent the fixing member from being too thick, which would affect the welding effect. This ensures that the connecting member is not too high, thus not wasting space on the top cover plate, and that the connecting part 420 is not too low, which would make manufacturing difficult. The vertical length B of the blocking part 421 is 0.05mm-4mm to ensure the strength of the fixing member while controlling its cost, avoiding excessive thickness that would increase costs. The length C of the blocking part in the horizontal direction is set between 0.1mm and 5mm, so as to ensure that the area of ​​the fixed member 42 and the negative electrode post 32 overlaps in the vertical direction. When the negative electrode post moves upward in the vertical direction, the blocking part 420 can apply a downward force to prevent the electrode post from moving upward.

[0044] In this embodiment, in the horizontal direction, the connecting part 420 is located outside the negative electrode upper plastic 52 and the negative electrode lower sealing ring 22, and the connecting part 420 does not overlap with the negative electrode upper plastic 52 and the negative electrode sealing ring 22 in the vertical direction. Therefore, compared with the prior art where the electrode post and upper plastic are first injection molded, and then assembled with the top cover plate and sealing ring before welding, the welding process involves sealing, affecting the sealing performance of the sealing components, thus reducing the pass rate of the top cover sealing. In this embodiment, since the negative electrode fixing component and the vertical protrusion 1102 are welded first, and then the upper plastic 52 is injection molded, the welding process will not have a thermal impact on the upper plastic 52 and sealing ring 22 that are directly sealed, thereby avoiding the adverse effects such as melting and failure of the upper plastic 52 and sealing ring made of plastic caused by the heat generated during the welding process. In this embodiment, welding does not participate in the sealing of the top cover during the entire manufacturing process. Welding only serves to fix the top cover. The welding can be full welding, gap welding, or even local spot welding. As long as the fixing strength meets the requirements, the airtightness of the top cover is guaranteed.

[0045] In this embodiment, the plastic 52 on the negative electrode, located between the top cover plate 10 and the negative electrode post 32, can restrict the vertical movement of the negative electrode post 32. At the same time, the blocking part 420 in the negative electrode fixing member 42 overlaps with the negative electrode post positioning part 211 in the vertical direction. Therefore, when the electrode assembly is subjected to a large external force and moves in the vertical direction, since the blocking part 420 is made of aluminum, the strength of aluminum is greater than that of the plastic 52, which is made of plastic. Therefore, the resistance of the electrode assembly to Z-direction force can be further increased, and the resistance of the electrode assembly to deformation and movement in the vertical direction can be enhanced. Example 2

[0046] The difference between this embodiment and Embodiment 1 is that the vertical protrusion 1108 in this embodiment is constructed as a column protruding upward from the main body 110 of the top cover, and the top of the vertical protrusion 1108 is stepped, forming a stepped shape with the outer side lower than the inner side relative to the electrode mounting hole. The cross-sectional shape of the fixing member 401 is L-shaped, but in this embodiment, the connecting part of the fixing member 401 is constructed as a stepped shape corresponding to the shape of the top of the vertical protrusion 1108. Since the top of the vertical protrusion 1108 is set as stepped in this embodiment, the height of the side of the vertical protrusion 1108 near the negative electrode mounting hole is higher than that on the outer side, which can restrict the horizontal movement of the fixing member 401 toward the negative electrode mounting hole, further restricting and positioning the fixing member 401. At the same time, the vertical protrusion can also further prevent the electrolyte flowing out of the injection hole from flowing toward the sealing member, reducing the impact of the electrolyte on the sealing member and improving the battery safety performance. Example 3

[0047] The difference between this embodiment and Embodiment 1 is that the vertical protrusion 1106 in this embodiment is constructed as a column protruding upward from the main body of the top cover, and the top end of the vertical protrusion 1106 is stepped, while the fixing member is constructed as a flat ring. When the fixing member 402 is installed at the top end of the vertical protrusion 1106, flush with the lower end of the top end of the vertical protrusion 1106, but with the higher end located outside the fixing member, the fixing member 402 is completely located inside the vertical protrusion 1106, thereby preventing the fixing member from moving outward in the horizontal direction and playing a positioning role for the fixing part. Example 4

[0048] The difference between this embodiment and Embodiment 1 is that the vertical protrusion 1107 in this embodiment is formed as a columnar structure, the top end of the vertical protrusion 1107 is planar, and the negative electrode fixing member 403 is formed as a complete ring. A part of the negative electrode fixing member 403 overlaps with the vertical protrusion 1107, and this part of the negative electrode fixing member 403 is welded to the vertical protrusion as a connecting part by through welding. Another part of the negative electrode fixing member 403 does not overlap with the vertical protrusion 1107. This part overlaps with the positioning part of the negative electrode post and a part of the plastic 52 on the negative electrode in the vertical direction. In the vertical direction, a part of the plastic 52 on the negative electrode is located between the negative electrode fixing member 403 and the vertical protrusion 1106.

[0049] The above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A secondary battery top cover, comprising: a pole post provided with a pole post body portion and a pole post positioning portion protruding in a horizontal direction relative to the pole post body portion; a top cover plate provided with a top cover plate body portion and a vertical protruding portion protruding in a vertical direction from the top cover plate body portion; a fixing member provided above the vertical protruding portion; characterized in that the fixing member comprises a connecting portion and a blocking portion, the blocking portion is located above the pole post positioning portion, the blocking portion protrudes in the horizontal direction relative to the connecting portion, and the cross-sectional configuration of the fixing member is L-shaped.

2. The top cover for a secondary battery according to claim 1, wherein The top end of the fixing member is configured in a stepped shape.

3. The top cover for a secondary battery according to claim 1, wherein The top end of the fixing member is configured in a flat surface.

4. The top cover for a secondary battery according to claim 1, wherein The top cover plate is further provided with a pole post assembly hole, and the height of the side of the fixing member close to the pole post assembly hole is higher than the side away from the pole post assembly hole.

5. The secondary battery top cover according to claim 1, wherein The fixing member is made of one or more of aluminum and steel.

6. The top cover for a secondary battery according to claim 1, wherein The height of the connecting portion in the vertical direction is 0.1-5 mm.

7. The top cover for a secondary battery according to claim 1, wherein The height of the blocking portion in the vertical direction is 0.05-4 mm.

8. The top cover for a secondary battery according to claim 1, wherein The length of the blocking portion in the horizontal direction is 0.1-5 mm.

9. The top cover for a secondary battery according to claim 1, wherein The top cover plate is further provided with a pole post assembly hole, and the height of the side of the fixing member close to the pole post assembly hole is less than the side away from the pole post assembly hole.

10. A secondary battery characterized by comprising: The secondary battery top cover comprises any one of the secondary battery top covers according to claims 1-9.

Images