Manufacturing method of battery top cover and battery

Abstract

The invention provides a manufacturing method of a battery top cover. The manufacturing method comprises the following steps: S01, forming a top cover plate 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; s02, mounting a pole in the stepped hole of the top cover plate; s03, a fixing component is welded to the vertical protruding part; the welding position of the fixing component and the vertical protruding part is located on the outer side of the pole in the horizontal direction; and S04, filling a gap among the fixing component, the pole, the vertical protruding part and the horizontal bearing part with upper plastic so as to connect the fixing component, the pole, the vertical protruding part and the horizontal bearing part into a whole. According to the manufacturing method of the battery top cover, the upper plastic is injected to the top cover after welding, the welding positions are located on the outer sides of the fixing component, the pole and the sealing ring, the problem that the sealing process is affected by welding is solved, and the safety performance and the air tightness of the battery top cover are improved.

Description

A method for manufacturing a battery top cover and the battery Technical Field

[0001] This application relates to the field of battery technology, and in particular to a method for manufacturing a battery top cover and a 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] In particular, the airtightness of the battery top cover is crucial to the battery's safety performance. In existing technologies, the top cover is generally connected to the sealing plastic using methods such as 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 due to the welding points simultaneously participating in the sealing process. Therefore, the airtightness of welded top covers is a critical control item. To improve the sealing performance of welded top covers, existing technologies also use a rolling process to achieve top cover sealing. However, the rolling process introduces a new problem: the supporting plastic may crack after rolling, leading to unpredictable risks to the top cover's airtightness and making its controllable.

[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. Summary of the Invention

[0006] To improve the airtightness and safety of the battery top cover, this invention provides a novel method for manufacturing a battery top cover, comprising: S01: forming a top cover plate having a top cover plate main body and a vertical protrusion protruding from the top cover plate main body in the vertical direction; forming the top cover plate includes: forming a through hole in the top cover plate main body; pressing an annular protrusion along the hole wall of the through hole; punching the top cover plate main body along the inner side of the annular protrusion to form a vertical protrusion and a horizontal bearing portion, wherein a first through hole is formed in the horizontal bearing portion, and a second through hole is formed in the vertical protrusion. Two through holes, the first through hole and the second through hole are connected to form a stepped hole; S02: Install the pole into the stepped hole of the top cover plate; S03: Weld the fixing member to the vertical protrusion; wherein, the welding point of the fixing member and the vertical protrusion is located on the outside of the pole in the horizontal direction; S04: Fill the gap between the fixing member, the pole, the vertical protrusion and the horizontal bearing part with plastic to connect the fixing member, the pole, the vertical protrusion and the horizontal bearing part into a whole.

[0007] Furthermore, before installing the pole into the stepped hole, the sealing ring is first placed on the lower end of the pole and then installed together into the stepped hole.

[0008] Furthermore, before installing the pole into the stepped hole, the sealing ring is first fitted into the first through hole.

[0009] Furthermore, the pole includes a pole body and a pole positioning part that protrudes horizontally relative to the pole body, the pole positioning part being located on the horizontal bearing part.

[0010] Furthermore, the fixing member is connected to the vertical protrusion by through welding.

[0011] Furthermore, the fixing member is connected to the vertical protrusion by means of seam welding.

[0012] Furthermore, it also includes connecting the lower plastic to the top cover plate by heat fusion.

[0013] Furthermore, it also includes welding the explosion-proof valve to the explosion-proof valve mounting hole of the top cover plate.

[0014] Furthermore, the fixing member is molded into an L-shape and installed on the vertical protrusion.

[0015] On the other hand, the present invention also provides a battery manufactured using the above-described manufacturing method.

[0016] The method for manufacturing the battery top cover of the present invention is to first weld and then inject the upper plastic onto the top cover. The weld is located on the outside of the fixing component, the terminal post and the sealing ring, which solves the problem of welding affecting the sealing process and improves the safety performance and airtightness of the battery top cover. Attached Figure Description

[0017] Figure 1 is a schematic flowchart of the manufacturing method of the battery top cover of the present invention; Figure 2 is a simplified view of the battery top cover of the first embodiment of the present invention; Figure 3 is an exploded view of the battery top cover of the first embodiment of the present invention; Figure 4 is a view of the lower plastic in the battery top cover of the first embodiment of the present invention; Figure 5 is a schematic diagram of the terminal post in the first embodiment of the present invention; Figure 6 is a cross-sectional schematic diagram of the battery top cover of the first embodiment of the present invention; Figure 7 is an enlarged schematic diagram of part K in Figure 6; Figure 8 is an enlarged schematic diagram of part F in Figure 6; Figure 9 is a schematic diagram of the fixing member in the first embodiment of the present invention; Figure 10 is a schematic diagram of the connection between the fixing member and the vertical protrusion in the top cover in the second embodiment of the present invention; Figure 11 is a schematic diagram of the connection between the fixing member and the vertical protrusion in the top cover in the third embodiment of the present invention; Figure 12 is a schematic diagram of the connection between the fixing member and the vertical protrusion in the top cover in the fourth embodiment of the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] To facilitate the description of the battery top cover and battery structure of the present invention, 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 horizontal direction is the left-right direction; the vertical direction is the up-down direction.

[0020] As shown in Figures 1-2, the battery top cover provided in this embodiment of the 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.

[0021] As shown in Figure 1, the top cover plate 10 of the present invention 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 an annular protrusion 1101 is pressed out 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 support portion 1103, thereby forming a vertical protrusion 1102 and a horizontal support portion 1103 on the horizontal support 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.

[0022] The specific structure and manufacturing method of the battery top cover of the present invention 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 fit the negative electrode sealing ring 22 onto 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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 the present invention is also 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.

[0027] 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. Embodiment 1

[0028] As shown in Figures 6-8, 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 space 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 space between the horizontal support portion 1103 and the negative electrode 32.

[0029] 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.

[0030] 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.

[0031] In this embodiment, the plastic 52 on the negative electrode, positioned between the top cover plate 10 and the negative electrode post 32, restricts the vertical movement of the negative electrode post 32. Simultaneously, the blocking portion 420 in the negative electrode fixing member 42 overlaps with the negative electrode post positioning portion 211 in the vertical direction. Therefore, when the electrode assembly is subjected to a large external force and moves vertically, the blocking portion 420, made of aluminum, has a higher strength than the plastic 52, further increasing the electrode assembly's resistance to Z-direction forces and enhancing its resistance to deformation and movement in the vertical direction. Example 2

[0032] 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 movement of the fixing member 401 in the horizontal direction toward the negative electrode mounting hole, and further restrict and position 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, reduce the impact of the electrolyte on the sealing member, and improve the battery safety performance. Embodiment 3

[0033] 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 providing a positioning function for the fixing part. Embodiment 4

[0034] 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.

[0035] The above embodiments of the present invention are merely illustrative examples to clearly illustrate the invention, and are not intended to limit the implementation of the invention. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively describe all possible implementations. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for manufacturing a battery top cover, characterized in that, include: S01: A top cover plate is formed having a top cover plate main body and a vertical protrusion protruding from the top cover plate main body in the vertical direction; Forming the top cover plate includes: forming a through hole in the main body of the top cover plate; pressing an annular protrusion along the wall of the through hole; punching the main body of the top cover plate along the inner side of the annular protrusion to form a vertical protrusion and a horizontal bearing portion, forming a first through hole in the horizontal bearing portion and a second through hole in the vertical protrusion, the first through hole and the second through hole communicating to form a stepped hole; S02: installing the pole post into the stepped hole of the top cover plate; S03: welding a fixing member to the vertical protrusion; wherein the welding point of the fixing member and the vertical protrusion is located on the outer side of the pole post in the horizontal direction; S04: filling the gap between the fixing member, the pole post, the vertical protrusion and the horizontal bearing portion with upper plastic to connect the fixing member, the pole post, the vertical protrusion and the horizontal bearing portion into a whole.

2. The method for manufacturing the battery top cover as described in claim 1, characterized in that, Before installing the pole into the stepped hole, first put the sealing ring on the lower end of the pole and then install them together into the stepped hole.

3. The method for manufacturing the battery top cover as described in claim 1, characterized in that, Before installing the pole into the stepped hole, first place the sealing ring inside the first through hole.

4. The method for manufacturing the battery top cover as described in claim 1, characterized in that, The pole includes a pole body and a pole positioning part that protrudes horizontally relative to the pole body, the pole positioning part being located on the horizontal bearing part.

5. The method for manufacturing the battery top cover as described in claim 1, characterized in that, The fixing component is connected to the vertical protrusion by through welding.

6. The method for manufacturing the battery top cover as described in claim 1, characterized in that, The fixing component is connected to the vertical protrusion by seam welding.

7. The method for manufacturing the battery top cover as described in claim 1, characterized in that, It also includes connecting the lower plastic to the top cover plate by heat fusion.

8. The method for manufacturing the battery top cover as described in claim 1, characterized in that, It also includes welding the explosion-proof valve to the explosion-proof valve mounting hole of the top cover plate.

9. The method for manufacturing the battery top cover as described in claim 8, characterized in that, The fixing component is molded into an L-shape and installed on the vertical protrusion.

10. A battery, characterized in that, Made by the manufacturing method as described in any one of claims 1-9.

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