Cover plate assembly, battery cell and battery pack
By setting an annular groove on the cover plate body and incorporating a second seal, the problem of electrolyte overflow during cell filling is solved, achieving a cell sealing effect, preventing cell corrosion, leakage, and failure, and improving the performance and lifespan of the battery pack.
Patent Information
- Application Number
- CN202520289426.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-21
- Publication Date
- 2025-12-02
- Estimated Expiration
- 2035-02-21
AI Technical Summary
During the electrolyte filling process, electrolyte can easily overflow, leading to a decrease in negative electrode resistance, which in turn causes cell corrosion, leakage, and failure.
An annular groove is provided on the cover plate body, a second seal is built in, and the second seal is squeezed by the first insulating member to form a seal, preventing the electrolyte from flowing to the electrode and preventing the electrolyte from overflowing.
It effectively prevents electrolyte leakage, ensures the negative electrode resistance and negative electrode voltage of the cell, prevents cell corrosion, leakage and failure, and improves the performance and service life of the battery pack.
Smart Images
Figure CN223625085U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of battery technology, specifically to a cover plate assembly, a battery cell, and a battery pack. Background Technology
[0002] The battery cell comprises a casing, electrode assembly, and cover plate assembly. The electrode assembly is located inside the casing, and the cover plate assembly covers the opening in the casing. The cover plate assembly includes a cover plate body, electrode post, sealing element, first insulating element, second insulating element, and riveting block. The cover plate body has electrode post holes. The sealing element is fitted onto the negative electrode post and then assembled into the electrode post holes to form a seal between the electrode post and the cover plate body. The first insulating element is attached to the outer wall surface of the cover plate body, and the second insulating element is attached to the inner wall surface of the cover plate body. The cover plate body has an electrolyte injection hole. During the process of injecting electrolyte into the casing after the battery cell is assembled, electrolyte overflow is likely to occur. The overflowing electrolyte flows along the outer surface of the cover plate body and the gap between the cover plate body and the first insulating element towards the negative electrode post. This reduces the negative electrode resistance of the battery cell, which in turn affects the negative electrode voltage, ultimately leading to corrosion, leakage, and battery failure. Utility Model Content
[0003] In view of this, the present invention provides a cover plate assembly, a battery cell, and a battery pack to solve the problem in the prior art where electrolyte overflowing from the filling hole of the battery cell easily leads to corrosion, leakage, and failure of the battery cell.
[0004] In a first aspect, this utility model provides a cover plate assembly, comprising:
[0005] First insulating component;
[0006] The cover plate body has an electrode post hole and an injection hole; the first insulating element is attached to the outer wall surface of the cover plate body, and an annular placement groove is provided on the outer wall surface of the cover plate body on the radially outer side of the electrode post hole.
[0007] The electrode post is disposed within the electrode post hole;
[0008] The first sealing element is sleeved outside the pole post and forms a seal between the pole post and the cover plate body;
[0009] The second seal is partially disposed within the annular groove, and the first insulator presses the second seal to form a seal between the first insulator and the cover plate body.
[0010] Beneficial effects: The cover plate assembly of this structure has an annular groove on the cover plate body, and a second sealing element is installed in the annular groove. Before compression, part of the second sealing element protrudes out of the annular groove. After the cover plate assembly is assembled, the first insulating element squeezes the second sealing element to form a seal between the first insulating element and the cover plate body. This can effectively block the gap between the first insulating element and the cover plate body, thereby blocking the flow path of the electrolyte and preventing the electrolyte overflowing during the injection process from flowing to the electrode through the gap. This can ensure the negative electrode resistance and negative electrode voltage of the battery cell and prevent corrosion, leakage and failure of the battery cell.
[0011] In one alternative embodiment, the compression amount of the second seal is K, where 8% ≤ K ≤ 30%.
[0012] Beneficial effects: This setting can control the compression of the second seal within a suitable range, which can ensure the sealing effect and prevent the first insulating part from lifting relative to the cover plate body due to excessive compression of the second seal. It can also ensure that the first insulating part is tightly attached to the outer wall surface of the cover plate body, preventing gaps between the two. It can also ensure the flatness of the first insulating part, thereby ensuring the welding flatness of the rivet block.
[0013] In one alternative embodiment, the longitudinal section of the second seal is circular.
[0014] In one alternative embodiment, the bottom surface of the second seal facing the bottom of the annular groove and the top surface facing the first insulator are both planar.
[0015] In one alternative embodiment, the diameter of the longitudinal section of the second seal before compression is d, and the width of the plane extending along the width direction of the annular groove is w1, where 0.3d≤w1≤d.
[0016] Beneficial effects: This arrangement ensures that the plane has sufficient width, further guaranteeing the ease of assembling the second seal into the annular groove and keeping the second seal stably within the annular groove. It also further improves the smoothness of the compression of the second seal by the first insulator, thereby further improving the sealing reliability of the second seal.
[0017] In one optional embodiment, the width of the annular groove is w2, and the diameter of the longitudinal section of the second seal before compression is d, where 0.5w2≤d≤0.8w2.
[0018] Beneficial effect: Before the second seal is compressed, the width of the annular groove is greater than the longitudinal section diameter of the second seal. This setting can reserve space for the expansion of the second seal after compression.
[0019] In one alternative embodiment, both the annular groove and the second seal have annular cross-sections.
[0020] In one optional embodiment, a positioning groove is provided on the outer wall surface of the cover plate body at the outer edge of the pole hole, and a positioning protrusion is provided on the inner wall surface of the first insulating member, the positioning protrusion being disposed in the positioning groove.
[0021] Secondly, this utility model provides a battery cell, including a cover plate assembly, an electrode assembly, and a housing as described in the above embodiments. The electrode assembly is disposed within the housing, and the cover plate assembly is disposed on an opening in the housing. The battery cell including the cover plate assembly has the same technical effects as the cover plate assembly, and will not be described further here.
[0022] Thirdly, this utility model provides a battery pack including the aforementioned battery cells. The battery pack includes a cover assembly, which has the same technical effects as the cover assembly, and will not be described in detail here. Attached Figure Description
[0023] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0024] Figure 1 This is a three-dimensional structural schematic diagram of a cover plate assembly according to an embodiment of the present utility model;
[0025] Figure 2 for Figure 1 Top view of the cover plate assembly shown;
[0026] Figure 3 for Figure 1 Sectional view along the middle AA direction;
[0027] Figure 4 for Figure 3 Enlarged view of part A in the middle;
[0028] Figure 5 for Figure 2 Sectional view along the BB direction;
[0029] Figure 6 for Figure 1 A three-dimensional structural diagram of the second sealing element;
[0030] Figure 7 for Figure 1 Top view of the second seal;
[0031] Figure 8 for Figure 7 A cross-sectional view along the CC direction;
[0032] Figure 9 for Figure 1 A three-dimensional structural diagram of the middle cover plate body;
[0033] Figure 10 for Figure 1 Top view of the middle cover plate body.
[0034] Explanation of reference numerals in the attached figures:
[0035] 1. First insulating component; 11. Positioning protrusion; 2. Cover plate body; 21. Pole post hole; 22. Liquid injection hole; 23. Annular positioning groove; 24. Positioning groove; 3. Pole post; 4. First sealing component; 5. Second sealing component; 6. Riveting block. Detailed Implementation
[0036] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0037] After the cover plate assembly of the battery cell is assembled, the first insulating component 1 is attached to the outer wall surface of the cover plate body 2. The first insulating component 1 is made of insulating materials such as plastic, while the cover plate body 2 is made of metal. There is a gap between the first insulating component 1 and the cover plate body 2. During the electrolyte injection process, the electrolyte is prone to overflow. The overflowing electrolyte is likely to flow along the outer wall surface of the cover plate body 2 to the gap between the first insulating component 1 and the cover plate body 2, and then flow from the gap to the negative electrode post 3. This will cause the negative electrode resistance of the battery cell to decrease, which in turn will cause the negative electrode voltage of the battery cell to decrease. When the negative electrode voltage decreases to a certain value, it will cause corrosion and leakage of the battery cell and battery cell failure.
[0038] The cover plate assembly is installed on the casing of the battery cell. The side of each component facing the outside of the battery cell is called the outer wall surface, and the side of each component facing the inside of the battery cell is called the inner wall surface.
[0039] The following is combined Figures 1 to 10 The following describes embodiments of the present invention.
[0040] According to an embodiment of the present invention, a cover plate assembly is provided, including a first insulating member 1, a cover plate body 2, an electrode post 3, a first sealing member 4, and a second sealing member 5.
[0041] The cover plate body 2 is provided with an electrode post hole 21 and an injection hole 22; the first insulating member 1 is attached to the outer wall surface of the cover plate body 2, and an annular placement groove 23 is provided on the outer wall surface of the cover plate body 2 on the radial outer side of the electrode post hole 21; the electrode post 3 is disposed in the electrode post hole 21; the first sealing member 4 is sleeved on the outside of the electrode post 3 and forms a seal between the electrode post 3 and the cover plate body 2; the second sealing member 5 is partially disposed in the annular placement groove 23, and the first insulating member 1 squeezes the second sealing member 5 to form a seal between the first insulating member 1 and the cover plate body 2.
[0042] In this cover plate assembly, an annular groove 23 is provided on the cover plate body 2, and a second sealing element 5 is provided in the annular groove 23. Before compression, part of the second sealing element 5 protrudes out of the annular groove 23. After the cover plate assembly is assembled, the first insulating element 1 squeezes the second sealing element 5 to form a seal between the first insulating element 1 and the cover plate body 2, which can effectively block the gap between the first insulating element 1 and the cover plate body 2, thereby blocking the flow path of the electrolyte and preventing the electrolyte overflowing during the injection process from flowing to the electrode post 3 through the gap, thus preventing the electrolyte from flowing to the negative electrode post. This can ensure the negative electrode resistance and negative electrode voltage of the battery cell and prevent corrosion, leakage and failure of the battery cell.
[0043] When the compression of the second sealing element 5 is small, it is impossible to form an effective seal between the first insulating element 1 and the cover plate body 2. When the compression of the second sealing element 5 is large, the first insulating element 1 is prone to warping after the second sealing element 5 is compressed. The inner wall surface of the first insulating element 1 cannot be kept parallel to the outer wall surface of the cover plate body 2, making it difficult to ensure the flatness of the first insulating element 1. A rivet block 6 needs to be set on the outer wall surface of the first insulating element 1. The rivet block 6 is welded to the pole post 3. The poor flatness of the first insulating element 1 cannot guarantee the welding flatness of the rivet block 6 and the pole post 3. To avoid these problems, in some optional embodiments, the compression amount of the second seal 5 is K, where 8% ≤ K ≤ 30%. This setting can control the compression amount of the second seal 5 within a suitable range, which can ensure the sealing effect and prevent the first insulating member 1 from tilting relative to the cover plate body 2 due to excessive compression of the second seal 5. It can also ensure that the first insulating member 1 is tightly attached to the outer wall surface of the cover plate body 2, preventing gaps between the two, and ensuring the flatness of the first insulating member 1, thereby ensuring the welding flatness of the rivet block 6.
[0044] Design a second seal 5 with different compression values, assemble the cover plate assembly, observe the fit between the first insulator 1 and the cover plate body 2 after assembly, drip electrolyte into the edge of the first insulator 1, tilt the cover plate assembly for a certain period of time, then disassemble the cover plate assembly and check whether electrolyte has passed through the area between the second seal 5 and the first insulator 1. The test results are shown in Table 1.
[0045] Table 1
[0046]
[0047] As shown in Examples 1 to 7, when the compression amount K of the second sealing element 5 satisfies 8% ≤ K ≤ 30%, after the cover plate assembly is assembled, the first insulating element 1 and the cover plate body 2 can fit tightly together without gaps, which can effectively ensure the flatness of the first insulating element 1, and the second sealing element 5 can seal reliably, preventing electrolyte from passing through the second sealing element 5, and the cover plate assembly passes the test. As shown in Comparative Examples 1 to 3, when the compression amount of the second sealing element 5 is less than 8%, the second sealing element 5 cannot form an effective seal between the first insulating element 1 and the cover plate body 2, and electrolyte can pass through the sealing area of the second sealing element 5, and the cover plate assembly fails the test. As shown in Comparative Examples 4 to 6, when the compression amount of the second sealing element 5 is greater than 30%, due to the excessive compression amount, after the cover plate assembly is assembled, the first insulating element 1 cannot fit onto the cover plate body 2, and the gap between them is large, making it impossible to ensure the flatness of the first insulating element 1, resulting in the cover plate assembly failing the test.
[0048] Before the second seal 5 is compressed, a section of its top is exposed in the annular groove 23. The height of the second seal 5 exposed in the annular groove 23 is h. The total height of the second seal 5 extending along the depth direction of the annular groove 23 is H. K = (Hh) / H × 100%. The compression amount of the second seal 5 can be adjusted by designing annular grooves 23 of different depths and second seal 5 of different heights.
[0049] like Figure 4 , Figure 5 and Figure 8 As shown, in some embodiments, the longitudinal section of the second seal 5 is circular. The structure of the second seal 5 is simple and reliable. The first insulating member 1 can effectively compress the second seal 5, and the second seal 5 can be fully compressed and expanded to form a good seal between the first insulating member 1 and the cover plate body 2.
[0050] In other embodiments, the longitudinal section of the second sealing member 5 may also be rectangular, trapezoidal or polygonal, as long as it can deform and expand after being squeezed to form a reliable seal between the first insulating member 1 and the cover plate body 2.
[0051] In some embodiments, such as Figure 4 , Figure 5 and Figure 8As shown, the bottom surface of the second sealing element 5 facing the bottom of the annular groove 23 and the top surface facing the first insulating element 1 are both flat. Correspondingly, the bottom of the annular groove 23 is flat, and the bottom surface of the second sealing element 5 is flat, which facilitates its assembly into the annular groove 23 and also helps the second sealing element 5 to be stably held in the annular groove 23. The top surface of the second sealing element 5 is flat, which facilitates the first insulating element 1 to smoothly squeeze and compress the second sealing element 5, ensuring that the first insulating element 1 is tightly attached to the outer wall surface of the cover plate body 2 after compression, which can improve the sealing reliability.
[0052] In some alternative embodiments, such as Figure 4 As shown, the diameter of the longitudinal section of the second seal 5 before compression is d, and the width of the plane extending along the width direction of the annular groove 23 is w1, where 0.3d≤w1≤d. This arrangement ensures that the plane has sufficient width, further guaranteeing the ease of assembly of the second seal 5 into the annular groove 23 and ensuring that the second seal 5 is stably held within the annular groove 23. Simultaneously, it further improves the smoothness of compression of the second seal 5 by the first insulating member 1, thereby further enhancing the sealing reliability of the second seal 5.
[0053] like Figure 4 As shown, in some embodiments, the width of the annular groove 23 is w2, and the diameter of the longitudinal section of the second seal 5 before compression is d, 0.5w2≤d≤0.8w2, that is, before the second seal 5 is compressed, the width of the annular groove 23 is greater than the diameter of the longitudinal section of the second seal 5. This setting can reserve expansion space after the second seal 5 is compressed.
[0054] In some alternative embodiments, such as Figures 6 to 9 As shown, the cross-sections of the annular groove 23 and the second sealing element 5 are both annular, and the electrode hole 21 is circular. The annular groove 23 is arranged around the outer periphery of the electrode hole 21, and the second sealing element 5 is arranged inside the annular groove 23, which can effectively prevent the overflowing electrolyte from entering the electrode hole 21 and the electrode 3 area.
[0055] In other embodiments, the annular groove 23 may also be in the shape of an elliptical ring, a rectangular ring, a parallelogram ring, etc. The annular groove 23 is arranged around the outer periphery of the pole post hole 21, and the cross-sectional shape of the second seal 5 is adapted to the shape of the annular groove 23.
[0056] like Figure 4As shown, in some embodiments, a positioning groove 24 is provided on the outer wall surface of the cover plate body 2 at the outer edge of the pole hole 21, and a positioning protrusion 11 is provided on the inner wall surface of the first insulating member 1, the positioning protrusion 11 being disposed within the positioning groove 24. During the assembly process of the first insulating member 1, the positioning protrusion 11 is aligned with the positioning groove 24 to facilitate the positioning and assembly of the first insulating member 1. The positioning groove 24 is located radially inside the annular positioning groove 23.
[0057] In some embodiments, the cover plate body 2 further includes a riveting block 6. The outer periphery of the first insulating member 1 is bent upward to form a flange. The riveting block 6 is disposed inside the flange. Before welding, the circumferential sidewall of the riveting block 6 is spaced apart from the inner sidewall of the flange to reserve expansion space after welding.
[0058] In some alternative embodiments, such as Figure 1 and Figure 2 As shown, the rivet block 6 is rectangular, and the cover assembly is suitable for use on blade batteries.
[0059] According to an embodiment of the present invention, another aspect provides a battery cell, including the aforementioned cover plate assembly, electrode group and housing, wherein the electrode group is disposed inside the housing and the cover plate assembly is disposed on the opening of the housing.
[0060] In this battery cell structure, the cover plate assembly has an annular groove 23 on the cover plate body 2. A second sealing element 5 is installed inside the annular groove 23. Before compression, part of the second sealing element 5 protrudes out of the annular groove 23. After the cover plate assembly is assembled, the first insulating element 1 squeezes the second sealing element 5 to form a seal between the first insulating element 1 and the cover plate body 2. This effectively blocks the gap between the first insulating element 1 and the cover plate body 2, thereby blocking the flow path of the electrolyte and preventing the electrolyte overflowing during the injection process from flowing to the electrode post 3 through the gap. This ensures the negative electrode resistance and negative electrode voltage of the battery cell and prevents corrosion, leakage, and failure of the battery cell.
[0061] According to an embodiment of the present invention, in another aspect, a battery pack is also provided, including the above-mentioned battery cell.
[0062] The cells inside the battery pack can effectively prevent the electrolyte overflowing during the filling process from flowing to the terminal 3, which can ensure the negative electrode resistance and negative electrode voltage of the cells, prevent the cells from corrosion, leakage and failure, thereby improving the performance and service life of the battery pack.
[0063] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.
Claims
1. A cover plate assembly, characterized in that, include: First insulating component; The cover plate body has an electrode post hole and an injection hole; the first insulating element is attached to the outer wall surface of the cover plate body, and an annular placement groove is provided on the outer wall surface of the cover plate body on the radially outer side of the electrode post hole. The electrode post is disposed within the electrode post hole; The first sealing element is sleeved outside the pole post and forms a seal between the pole post and the cover plate body; The second seal is partially disposed within the annular groove, and the first insulator presses the second seal to form a seal between the first insulator and the cover plate body.
2. The cover plate assembly according to claim 1, characterized in that, The compression amount of the second seal is K, where 8% ≤ K ≤ 30%.
3. The cover plate assembly according to claim 1 or 2, characterized in that, The longitudinal section of the second seal is circular.
4. The cover plate assembly according to claim 3, characterized in that, The bottom surface of the second sealing member facing the bottom of the annular groove and the top surface facing the first insulating member are both planar.
5. The cover plate assembly according to claim 4, characterized in that, The diameter of the longitudinal section of the second seal before compression is d, and the width of the plane extending along the width direction of the annular groove is w1, where 0.3d≤w1≤d.
6. The cover plate assembly according to claim 3, characterized in that, The width of the annular groove is w2, and the diameter of the longitudinal section of the second seal before compression is d, where 0.5w2≤d≤0.8w2.
7. The cover plate assembly according to claim 1 or 2, characterized in that, Both the annular groove and the second seal have annular cross-sections.
8. The cover plate assembly according to claim 1 or 2, characterized in that, A positioning groove is provided on the outer wall surface of the cover plate body at the outer edge of the pole hole, and a positioning protrusion is provided on the inner wall surface of the first insulating member, the positioning protrusion being located in the positioning groove.
9. A battery cell, characterized in that, The device includes a cover plate assembly, an electrode assembly, and a housing as described in any one of claims 1 to 8, wherein the electrode assembly is disposed within the housing, and the cover plate assembly is disposed on an opening in the housing.
10. A battery pack, characterized in that, Includes the battery cell described in claim 9.