Battery cover plate and battery

Abstract

A battery cover plate and a battery. In addition to a sealing nail (2) and a cover plate body (1), the battery cover plate further comprises a fixing plate (3) which is welded to the cover plate body (1), and a sealing cover (4); a limiting groove (31), a plug-in through hole (32) and a clearance notch (33) are provided in the side of the fixing plate (3) facing the cover plate body (1); the sealing cover (4) comprises a cylindrical portion (41) which is rotationally inserted into the plug-in through hole (32) and a limiting portion (42) which rotates with the cylindrical portion (41) in the limiting groove (31); the area of a projection of the limiting portion (42) is less than that of the clearance notch (33); and the thickness of the fixing plate (3) is T, and the depth of the limiting groove (31) is H, which satisfy 40% ≤ (T-H) / T x 100% ≤ 60%.

Description

Battery cover and battery

[0001] This application claims priority to Chinese Patent Application No. 202411170941.X, filed with the Chinese Patent Office on August 26, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of battery technology, for example to a battery cover and a battery. Background Technology

[0003] Electrolyte is required during battery cycling. During initial battery assembly, an injection hole is created on the battery cover for injecting electrolyte into the battery. After injection, the injection hole is sealed with a sealing pin. Finally, a sealing cap is welded to the battery cover to seal the sealing pin and prevent damage to it, which could lead to leakage.

[0004] However, during battery cycling, the electrolyte is continuously depleted. Because the sealing cap is welded to the battery cover, the electrolyte filling hole cannot be reopened, thus preventing the replenishment of electrolyte and severely limiting the battery's lifespan. Summary of the Invention

[0005] This application provides a battery cover and a battery that can be replenished with electrolyte at any time and has a long cycle life.

[0006] On one hand, this application provides a battery cover, which includes a cover body and a sealing pin. The cover body has a liquid injection hole, and the sealing pin is inserted into the liquid injection hole. The battery cover also includes:

[0007] A fixing plate is welded to the cover plate body. A limiting groove is formed on one side of the fixing plate facing the cover plate body. The fixing plate also has an insertion through hole communicating with the limiting groove, and an avoidance notch communicating with both the insertion through hole and the limiting groove.

[0008] A sealing cap, comprising a cylindrical portion and a limiting portion, wherein the cylindrical portion is disposed above the sealing nail and is rotatably inserted into the insertion through hole, and the limiting portion is disposed on the outer periphery of the cylindrical portion and abuts against the bottom of the limiting groove, the limiting portion being able to rotate with the cylindrical portion in the limiting groove, and the projected area of ​​the limiting portion on the cover plate body along the first direction being smaller than the projected area of ​​the clearance notch on the cover plate body along the first direction;

[0009] The thickness of the fixing plate along the first direction is T, and the depth of the limiting groove along the first direction is H, and both satisfy 40% ≤ (TH) / T × 100% ≤ 60%.

[0010] In some embodiments, the width dimension of the overlapping area between the limiting portion and the limiting groove along the second direction is W, and W≥0.5 mm.

[0011] In some embodiments, the battery cover further includes a seal, and the sealing cover has a positioning groove on the side facing the sealing pin, and the seal is accommodated in the positioning groove.

[0012] In some embodiments, the height dimension of the seal along the first direction is D, the groove depth dimension of the positioning groove along the first direction is d, and satisfies 0.5≤d / D≤0.8.

[0013] In some embodiments, the sealing pin includes a plugging portion and a plugging portion connected to the plugging portion, the plugging portion being configured to guide the plugging portion into the injection hole so that the plugging portion seals the injection hole;

[0014] The diameter of the sealing part is A, and the diameter of the injection hole is B, and both satisfy 3% ≤ (AB) / A × 100% ≤ 12%.

[0015] In some embodiments, the sealing cover includes a plurality of limiting portions spaced apart on the outer periphery of the column portion, and the fixing plate has a relief notch corresponding to each of the plurality of limiting portions. The plurality of relief notches and the plurality of limiting portions have the same distribution pattern, and the projected area of ​​each limiting portion on the cover plate body along the first direction is smaller than the projected area of ​​the corresponding relief notch on the cover plate body along the first direction.

[0016] In some embodiments, the column portion has a slot on the side opposite to the cover plate body.

[0017] In some embodiments, the cover plate body has an installation groove, the liquid injection hole is opened at the bottom of the installation groove, the fixing plate is disposed in the installation groove, and is configured to press the sealing cover above the sealing nail.

[0018] In some embodiments, the fixing plate is provided with a welding bevel for welding to the cover plate body.

[0019] On the other hand, this application also provides a battery, which includes a battery cover as described in any of the above embodiments, and the battery also includes a housing and an electrode assembly. The battery cover is disposed on the housing to form a receiving chamber for storing the electrode assembly. Attached Figure Description

[0020] Figure 1 is an exploded view of the battery cover provided in this application;

[0021] Figure 2 is a partial structural cross-sectional view of the battery cover provided in this application;

[0022] Figure 3 is an enlarged view of part A in Figure 2;

[0023] Figure 4 is a schematic diagram of the sealing nail in the battery cover provided in this application;

[0024] Figure 5 is a schematic diagram of the structure of the fixing plate in the battery cover provided in this application;

[0025] Figure 6 is a structural cross-sectional view of the fixing plate in the battery cover provided in this application;

[0026] Figure 7 is a schematic diagram of the sealing cover in the battery cover plate provided in this application;

[0027] Figure 8 is a structural cross-sectional view of the sealing cover in the battery cover plate provided in this application;

[0028] Figure 9 is an exploded view of the battery structure provided in this application.

[0029] In the diagram: 100, housing; 200, electrode assembly; 1, cover plate body; 11, injection hole; 12, mounting groove; 2, sealing pin; 21, sealing part; 22, insertion part; 23, guide cone surface; 3, fixing plate; 31, limiting groove; 32, insertion through hole; 33, clearance notch; 34, welding bevel; 4, sealing cap; 41, column part; 42, limiting part; 43, pressing protrusion; 44, positioning groove; 45, slot; 5, sealing element. Detailed Implementation

[0030] The present application will now be described in conjunction with the accompanying drawings and embodiments. The embodiments described herein are for the purpose of explaining the present application. For ease of description, only the parts of the structure relevant to the present application are shown in the drawings.

[0031] In the description of this application, unless otherwise expressly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the meaning of the above terms in this application as appropriate.

[0032] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or indicating that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or indicating that the first feature is at a lower horizontal level than the second feature.

[0033] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of description and simplification of operation, 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. Furthermore, the terms "first" and "second" are used for distinction in description and have no special meaning.

[0034] Electrolyte is required during battery cycling. During initial battery assembly, an injection hole is created on the battery cover for injecting electrolyte into the battery. After injection, the injection hole is sealed with a sealing pin. Finally, a sealing cap is welded to the battery cover to seal the sealing pin and prevent damage to it, which could lead to leakage.

[0035] However, during battery cycling, the electrolyte is continuously depleted. Because the sealing cap is welded to the battery cover, the electrolyte filling hole cannot be reopened, thus preventing the replenishment of electrolyte and severely limiting the battery's lifespan.

[0036] To ensure airtightness while facilitating the replenishment of electrolyte at any time, this embodiment provides a battery cover plate, which includes a cover plate body 1 and a sealing nail 2. The cover plate body 1 has an injection hole 11, and the sealing nail 2 is inserted into the injection hole 11.

[0037] As shown in Figures 1 to 8, the battery cover also includes a fixing plate 3 and a sealing cover 4. The fixing plate 3 is welded to the cover body 1. A limiting groove 31 is formed on the side of the fixing plate 3 facing the cover body 1. The fixing plate 3 also has an insertion through hole 32 communicating with the limiting groove 31, and an avoidance notch 33 communicating with both the insertion through hole 32 and the limiting groove 31. The sealing cover 4 includes a column part 41 and a limiting part 42. The column part 41 is located above the sealing nail 2 and is rotatably inserted into the insertion through hole 32. The limiting part 42 is located on the outer periphery of the column part 41 and abuts against the bottom of the limiting groove 31. The limiting part 42 can rotate with the column part 41 in the limiting groove 31. The projection area of ​​the limiting part 42 on the cover plate body 1 along the first direction is smaller than the projection area of ​​the avoidance notch 33 on the cover plate body 1 along the first direction; the thickness dimension of the fixing plate 3 along the first direction is T, and the depth dimension of the limiting groove 31 along the first direction is H, and satisfies 40%≤(TH) / T×100%≤60%.

[0038] By providing a limiting groove 31 and an insertion through hole 32 communicating with the limiting groove 31 on the fixing plate 3, when the fixing plate 3 is inserted into the column part 41 of the sealing cover 4 through the insertion through hole 32, the bottom of the groove of the limiting groove 31 of the fixing plate 3 can abut against the limiting part 42 of the sealing cover 4, so that the fixing plate 3 connected to the cover plate body 1 fixes the sealing cover 4 to the cover plate body 1, wherein the column part 41 is rotatably connected in the insertion through hole 32, so that the limiting part 42 connected to the column part 41 can rotate within the limiting groove 31 as the column part 41 rotates. When electrolyte needs to be replenished, since the projected area of ​​the limiting part 42 on the cover plate body 1 is smaller than the projected area of ​​the clearance notch 33 on the cover plate body 1, it is only necessary to rotate the limiting part 42 to the clearance notch 33 to release the limiting of the fixing plate 3 on the sealing cover 4, so that the sealing cover 4 can be directly removed from the battery cover plate, exposing the sealing nail 2 located below the sealing cover 4. Then, the sealing nail 2 can be removed, and electrolyte can be replenished through the injection hole 11 on the cover plate body 1. Furthermore, by limiting the thickness T of the fixing plate 3 and the depth H of the limiting groove 31, both are made to satisfy 40% ≤ (TH) / T × 100% ≤ 60%, thereby ensuring that the fixing plate 3 still has sufficient structural strength after the limiting groove 31 is opened to resist the pressure from inside the battery and avoid deformation.

[0039] This battery cover can be applied to different types of batteries, such as blade batteries or prismatic batteries. In this embodiment, the battery cover is used on a prismatic battery. The sealing pin 2 and the injection hole 11 are interference-fitted to seal the injection hole 11. Furthermore, the shapes of the limiting part 42 on the sealing cover 4 and the clearance notch 33 on the fixing plate 3 can be freely set according to requirements, as long as the projected area of ​​the limiting part 42 on the cover body 1 is smaller than the projected area of ​​the clearance notch 33 on the cover body 1. In this embodiment, the limiting part 42 has a rectangular cross-section, and the clearance notch 33 is a rectangular groove communicating with the limiting groove 31 and the insertion through hole 32.

[0040] Optionally, as shown in Figure 3, the width of the overlapping area between the limiting part 42 and the limiting groove 31 along the second direction is W, and W ≥ 0.5 mm. By limiting the width W of the overlapping area between the limiting part 42 and the limiting groove 31, the bottom of the limiting part 42 and the limiting groove 31 have sufficient contact area, avoiding excessive local pressure due to insufficient contact area, which could lead to excessive force on the area where the limiting groove 31 is opened on the fixing plate 3, causing deformation of the fixing plate 3.

[0041] To determine the influence of the thickness T of the fixing plate 3, the depth H of the limiting groove 31, and the width W of the overlapping area between the limiting part 42 and the limiting groove 31 on the structural strength of the fixing plate 3 after the limiting groove 31 is opened, as shown in Tables 1 and 2, twelve embodiments and fifteen comparative examples were listed for experimental verification. The simulation showed that when the internal gas pressure of the battery reached 1.2 megapascals (MPa) or higher, the sealing cover 4 and the fixing plate 3 would not deform after locking, that is, to ensure that the deformation resistance of the area where the limiting groove 31 is opened on the fixing plate 3 is above 1.2 MPa.

[0042] Table 1

[0043] As can be seen from Examples 1 to 12, when the thickness T of the fixing plate 3 and the depth H of the limiting groove 31 meet the range of 40% ≤ (TH) / T×100% ≤ 60%, and the width W of the overlapping area between the limiting part 42 and the limiting groove 31 meets the range of W ≥ 0.5 mm, the fixing plate 3 can withstand a pressure greater than 1.2 MPa, and the structural strength of the fixing plate 3 meets the usage requirements.

[0044] Table 2

[0045] As can be seen from Comparative Examples 1 to 5, when the thickness T of the fixing plate 3 and the depth H of the limiting groove 31 satisfy the range of 40% ≤ (TH) / T×100% ≤ 60%, even if the width W of the overlapping area between the limiting part 42 and the limiting groove 31 is less than the minimum value of W ≥ 0.5 mm, the fixing plate 3 can still withstand a pressure greater than 1.2 MPa. The structural strength of the fixing plate 3 meets the usage requirements. It can also be observed that as the width W of the overlapping area between the limiting part 42 and the limiting groove 31 gradually increases, the maximum pressure that the fixing plate 3 can withstand gradually increases.

[0046] As can be seen from Comparative Examples 6 to 10, when the thickness T of the fixing plate 3 and the depth H of the limiting groove 31 are greater than the maximum value of the range 40% ≤ (TH) / T × 100% ≤ 60%, the fixing plate 3 can withstand a pressure greater than 1.2 MPa. The structural strength of the fixing plate 3 meets the usage requirements, but it leads to an increase in the size of the fixing plate 3, resulting in increased material usage and higher costs.

[0047] As can be seen from Comparative Examples 7 to 15, when the thickness T of the fixing plate 3 and the depth H of the limiting groove 31 are less than the minimum value of the range 40% ≤ (TH) / T×100% ≤ 60%, and the width W of the overlapping area between the limiting part 42 and the limiting groove 31 is less than the minimum value of the range W ≥ 0.5mm, the pressure that the fixing plate 3 can withstand is less than 1.2 MPa. Therefore, the structural strength of the fixing plate 3 does not meet the usage requirements.

[0048] Optionally, as shown in Figures 3 and 8, the battery cover also includes a sealing element 5. A positioning groove 44 is provided on the side of the sealing cover 4 facing the sealing nail 2, and the sealing element 5 is housed in the positioning groove 44. By providing installation space for the sealing element 5 through the positioning groove 44 on the sealing cover 4, a portion of the sealing element 5 overlaps with the sealing cover 4, thereby making the battery cover structure more compact and its overall dimensions smaller.

[0049] In this embodiment, since the sealing cover 4 is provided with a positioning groove 44, a pressing protrusion 43 for abutting against the sealing nail 2 can be formed on the sealing cover 4. When the battery generates pressurized gas and pushes the sealing nail 2 upward, the pressing protrusion 43 in contact with the sealing nail 2 can transmit the thrust in sequence through the column part 41, the limiting part 42 and the fixing plate 3, and finally to the cover body 1 welded to the fixing plate 3, thus blocking the thrust brought by the internal pressurized gas.

[0050] Optionally, as shown in Figures 3 and 8, the height dimension of the sealing element 5 along the first direction is D, and the groove depth dimension of the positioning groove 44 along the first direction is d, satisfying 0.5≤d / D≤0.8. By limiting the diameter dimension D of the sealing element 5 and the groove depth dimension d of the positioning groove 44, both satisfying 0.5≤d / D≤0.8, the sealing element 5 can protrude from the positioning groove 44. When the sealing cover 4 presses against the cover plate body 1, the sealing element 5 deforms under pressure, which can seal not only the two opposing sides of the cover plate body 1 and the sealing cover 4, but also the side wall of the positioning groove 44, resulting in a strong sealing effect.

[0051] Optionally, as shown in Figures 3 and 4, the sealing pin 2 includes a plugging part 21 and a plugging part 22 connected to the plugging part 21. The plugging part 22 is used to guide the plugging part 21 into the injection hole 11 so that the plugging part 21 seals the injection hole 11. The diameter of the plugging part 21 is A, and the diameter of the injection hole 11 is B, and both satisfy 3% ≤ (AB) / A × 100% ≤ 12%. By limiting the diameter A of the sealing pin 2 and the diameter B of the injection hole 11, so that both satisfy 3% ≤ (AB) / A × 100% ≤ 12%, the interference fit between the sealing pin 2 and the injection hole 11 is determined. On the one hand, this improves the sealing effect of the sealing pin 2 on the injection hole 11, and on the other hand, it avoids that the interference fit is too large, making it difficult for the sealing pin 2 to be inserted into the injection hole 11.

[0052] In this embodiment, since the sealing part 21 and the injection hole 11 are interference fit, it is very difficult to directly insert the sealing part 21 into the injection hole 11. Therefore, by providing a plug-in part 22 connected to the sealing part 21, and providing a guide cone surface 23 on the plug-in part 22, it is convenient for the plug-in part 22 to be inserted into the injection hole 11. As the insertion depth increases, the injection hole 11 gradually expands, thereby guiding the sealing part 21 into the injection hole 11. Finally, the injection hole 11 recovers under its own deformation force, thereby holding the sealing part 21 tightly and achieving a seal.

[0053] Optionally, as shown in Figures 5 to 8, the sealing cover 4 includes a plurality of limiting portions 42 spaced apart on the outer periphery of the column portion 41, and the fixing plate 3 has a relief notch 33 corresponding to the plurality of limiting portions 42. The plurality of relief notches 33 and the plurality of limiting portions 42 have the same distribution pattern, and the projected area of ​​each limiting portion 42 on the cover plate body 1 along the first direction is smaller than the projected area of ​​the corresponding relief notch 33 on the cover plate body 1 along the first direction. By providing multiple limiting parts 42 on the sealing cover 4, the contact area between the sealing cover 4 and the fixing plate 3 is ensured, thereby ensuring the strength of the fixing plate 3 in fixing the sealing cover 4. The multiple clearance notches 33 and the multiple limiting parts 42 are kept in the same distribution pattern, so that when one limiting part 42 is aligned with the clearance notch 33, the other limiting parts 42 are also aligned with the clearance notch 33 at the corresponding position. Since the projected area of ​​each limiting part 42 on the cover plate body 1 along the first direction is smaller than the projected area of ​​the corresponding clearance notch 33 on the cover plate body 1 along the first direction, the sealing cover 4 can be removed.

[0054] In this embodiment, two limiting parts 42 are symmetrically distributed on the outer periphery of the cylindrical part 41 of the sealing cover 4. Correspondingly, two clearance notches 33 are symmetrically distributed outside the insertion through hole 32 on the fixing plate 3.

[0055] Optionally, as shown in Figure 7, a slot 45 is provided on the side of the column portion 41 facing away from the cover plate body 1. By providing a slot 45 on the side of the column portion 41 facing away from the cover plate body 1, it is convenient for the operator to use a screwdriver to tighten the sealing cover 4, thereby facilitating the alignment or misalignment of the limiting portion 42 and the clearance notch 33. In this embodiment, the shape of the slot 45 can be straight or cross-shaped.

[0056] Optionally, as shown in Figure 1, a mounting groove 12 is provided on the cover plate body 1, and an injection hole 11 is provided at the bottom of the mounting groove 12. A fixing plate 3 is disposed in the mounting groove 12 and is used to press the sealing cap 4 onto the sealing nail 2. By providing a mounting groove 12 on the cover plate body 1, it is convenient to accommodate the fixing plate 3 and the sealing cap 4, and the depth of the injection hole 11 can be shortened, thereby allowing the use of a sealing nail 2 with a smaller length, and avoiding damage to the electrode assembly 200 due to excessive length of the sealing nail 2.

[0057] In this embodiment, the shape of the fixing plate 3 and the shape of the mounting groove 12 can be freely set according to the requirements, as long as the shape of the fixing plate 3 and the shape of the mounting groove 12 are compatible. In this embodiment, the shape of the fixing plate 3 is circular, and the mounting groove 12 is a circular groove that is compatible with it.

[0058] Optionally, the fixing plate 3 is provided with a welding bevel 34 for welding to the cover plate body 1. By providing a welding bevel 34 on the fixing plate 3, welding between the fixing plate 3 and the cover plate body 1 is facilitated. In this embodiment, in order to ensure the strength of the weld between the fixing plate 3 and the cover plate body 1, a welding bevel is also provided on the edge of the mounting groove 12 of the cover plate body 1. By connecting the two welding bevels, the welding area is increased, thereby improving the strength of the weld between the fixing plate 3 and the cover plate body 1.

[0059] In this embodiment, as shown in FIG9, a battery is also provided, which includes the battery cover plate described above. The battery also includes a housing 100 and an electrode assembly 200. The battery cover plate is disposed on the housing 100 to form a receiving chamber for storing the electrode assembly 200. By using the battery cover plate described above, the electrolyte can be replenished at any time, extending the battery's cycle life.

Claims

1. A battery cover, the battery cover comprising a cover body and a sealing pin, wherein the cover body has an injection hole, and the sealing pin is inserted into the injection hole, the battery cover further comprising: A fixing plate is welded to the cover plate body. A limiting groove is formed on one side of the fixing plate facing the cover plate body. The fixing plate also has an insertion through hole communicating with the limiting groove, and an avoidance notch communicating with both the insertion through hole and the limiting groove. A sealing cap, comprising a cylindrical portion and a limiting portion, wherein the cylindrical portion is disposed above the sealing nail and is rotatably inserted into the insertion through hole, and the limiting portion is disposed on the outer periphery of the cylindrical portion and abuts against the bottom of the limiting groove, the limiting portion being able to rotate with the cylindrical portion in the limiting groove, and the projected area of ​​the limiting portion on the cover plate body along the first direction being smaller than the projected area of ​​the clearance notch on the cover plate body along the first direction; The thickness of the fixing plate along the first direction is T, and the depth of the limiting groove along the first direction is H, and both satisfy 40% ≤ (TH) / T × 100% ≤ 60%.

2. The battery cover according to claim 1, wherein, The width of the overlapping area between the limiting part and the limiting groove along the second direction is W, and W≥0.5 mm.

3. The battery cover according to claim 1 further includes a sealing element, wherein the sealing cover has a positioning groove on the side facing the sealing nail, and the sealing element is accommodated in the positioning groove.

4. The battery cover according to claim 3, wherein, The height dimension of the seal along the first direction is D, and the groove depth dimension of the positioning groove along the first direction is d, and satisfies 0.5≤d / D≤0.

8.

5. The battery cover according to claim 1, wherein, The sealing pin includes a plugging part and a plugging part connected to the plugging part. The plugging part is configured to guide the plugging part into the injection hole so that the plugging part seals the injection hole. The diameter of the sealing part is A, and the diameter of the injection hole is B, and both satisfy 3% ≤ (AB) / A × 100% ≤ 12%.

6. The battery cover according to claim 1, wherein, The sealing cover includes a plurality of limiting portions spaced apart on the outer periphery of the column portion. The fixing plate has a relief notch corresponding to each of the plurality of limiting portions. The plurality of relief notches and the plurality of limiting portions have the same distribution pattern. The projected area of ​​each limiting portion on the cover plate body along the first direction is smaller than the projected area of ​​the corresponding relief notch on the cover plate body along the first direction.

7. The battery cover according to claim 1, wherein, The column portion has a slot on the side opposite to the cover plate body.

8. The battery cover according to claim 1, wherein, The cover plate body has an installation groove, the liquid injection hole is opened at the bottom of the installation groove, the fixing plate is disposed in the installation groove and is configured to press the sealing cover above the sealing nail.

9. The battery cover according to claim 1, wherein, The fixing plate is provided with a welding bevel for welding to the cover plate body.

10. A battery comprising a battery cover as described in any one of claims 1-9, the battery further comprising a housing and an electrode assembly, the battery cover being disposed on the housing to form a receiving chamber for storing the electrode assembly.

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