Cover plate assembly and battery

Abstract

The invention relates to the technical field of batteries, and discloses a cover plate assembly and a battery. The cover plate assembly comprises a cover plate provided with a pole hole, the pole hole at least comprises a riveting section, the inner circumferential surface of the riveting section comprises two arc-shaped surfaces oppositely arranged in the length direction and two rectangular surfaces oppositely arranged in the width direction, the distance between the two rectangular surfaces in the width direction is E, the diameter of the arc-shaped surfaces is D, E is larger than D, and E is larger than D; an avoiding space is formed on the riveting section; the polar column comprises a column body, the column body comprises a first column part, the first column part is arranged in the polar column hole in a penetrating mode, the size of the first column part in the width direction is A, and E, D and A meet the relational expression that the sealing ring is arranged between the polar column and the cover plate. Therefore, the avoidance space can provide enough material expansion space, the consistency of the width of the riveted cover plate is ensured, the reduction of the sealing area is avoided, the sealing property of the cover plate assembly is ensured, and the safety of the battery is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a cover plate assembly and a battery. Background Art

[0002] The cover plate assembly is a key accessory in the battery. It has the functions of welding with the shell to form a sealed cavity, leading the positive and negative electrodes of the electrode group, and serving as an assembly carrier. The cover plate assembly is composed of a cover plate, a rivet block, an upper plastic, a pole, a lower plastic, a sealing ring and other structures. The pole is passed through the through hole on the cover plate and the through hole on the rivet block. The pole is riveted to the cover plate through the rivet block. After riveting, the pole moves along the direction perpendicular to the axis of the pole and expands, squeezing the cover plate. The cover plate width of the blade battery is relatively small. After the pole and the cover plate are riveted, it is easy to cause the cover plate to swell and deform severely in the width direction. The edge of the cover plate is propped outward by the pole, resulting in excessive width of the cover plate and poor width consistency of the cover plate, which in turn leads to problems such as difficulty in assembling the shell cover and poor welding. Summary of the Invention

[0003] In view of this, the present invention provides a cover plate assembly and a battery to solve the problem that the cover plate is easily squeezed by the pole and deformed, resulting in poor consistency in the width of the cover plate.

[0004] In a first aspect, the present invention provides a cover plate assembly, comprising: a cover plate having a pole hole, the pole hole comprising at least a riveted section, the inner circumference of the riveted section comprising two arcuate surfaces arranged opposite to each other along the length direction, and two rectangular surfaces arranged opposite to each other along the width direction, the distance between the two rectangular surfaces along the width direction being E, the diameter of the arcuate surface being D, wherein E>D, so as to form an avoidance space on the riveted section; a pole comprising a column, the column comprising a first column portion, the first column portion being arranged in the pole hole, the dimension of the first column portion along the width direction being A, wherein E, D, and A satisfy the relationship: A sealing ring is provided between the pole and the cover plate.

[0005] Beneficial effect: By setting the distance E between the two rectangular surfaces on the inner circumference of the riveted section of the pole hole to be greater than the diameter D of the arc surface, an avoidance space is formed on the riveted section. The avoidance space is reserved for the first column portion of the pole to expand during the riveting process, meeting the expansion demand of the first column portion, avoiding the first column portion from excessively squeezing the riveted section and causing the cover plate to expand and deform in the width direction, thereby avoiding excessive width of the cover plate, ensuring the consistency of the width of the cover plate after riveting, and avoiding problems such as difficulty in assembling the shell cover and poor welding. In addition, by limiting the distance E between the two rectangular surfaces, the diameter D of the arc surface and the dimension A of the first column portion in the width direction, the following conditions are met: The relationship formula is used to limit the concave size of the avoidance space along the width direction to a reasonable range, which can not only ensure that the avoidance space can provide sufficient space for material expansion, thereby ensuring the consistency of the cover width after riveting, but also avoid the reduction of the sealing area due to the extrusion pressure on the sealing ring being too small, thereby ensuring the sealing of the cover assembly and improving the safety of the battery.

[0006] In an optional embodiment, an escape space is provided on each side of the riveted section along the width direction, and each of the escape spaces includes at least a first escape portion formed by a straight section of the runway-shaped through hole being recessed in a direction away from the center of the pole hole, and the recess depth of each first escape portion is t, wherein t=(ED) / 2, 0.1mm≤t≤0.5mm.

[0007] Beneficial effect: By setting a avoidance space on each side of the riveting section along the width direction, and the recessed depths of the two first avoidance parts are equal, the symmetry of the avoidance space on the pole hole along the width direction is ensured, thereby ensuring the uniformity of the material expansion space provided by the avoidance space, and avoiding the convex deformation of one side of the cover plate along the width direction due to insufficient material expansion space on one side during the riveting process of the pole, thereby ensuring the consistency of the cover plate width after riveting, and avoiding the problem of excessive cover plate width; and, by limiting the recessed depth t of each first avoidance part to a value within the range of 0.1mm to 0.5mm, it can be ensured that the avoidance space can provide sufficient material expansion space, ensure the consistency of the cover plate width after riveting, reduce the difficulty of cover plate stamping processing, ensure the qualified rate of the cover plate, and avoid insufficient contact surface between the cover plate and the sealing ring, thereby ensuring the sealing of the cover plate assembly.

[0008] In an optional embodiment, the rectangular surface and the arcuate surface are connected via an inclined surface, and an inclination angle of the inclined surface relative to the rectangular surface is θ, wherein 110°≤θ≤160°.

[0009] Beneficial effect: By setting the rectangular surface and the curved surface to be connected by a bevel, on the one hand, it is convenient for the processing and forming of the avoidance space, and on the other hand, it further increases the expansion space that can be provided by the avoidance space, thereby meeting the expansion requirements of the first column part during the riveting process of the pole; by limiting the inclination angle θ of the bevel relative to the rectangular surface to a value between 110° and 160°, it can avoid the corner between the rectangular surface and the curved surface being too sharp and scratching the sealing ring, and can also ensure that the cover plate can provide sufficient compression for the sealing ring, thereby ensuring the sealing of the cover plate assembly.

[0010] In an optional embodiment, the sealing ring includes at least a first ring portion sleeved on the outer peripheral side of the first column portion, and the ring width of the first ring portion is M, wherein M satisfies the relationship between D and A:

[0011]

[0012] Beneficial effects: ensuring smooth assembly of the cover plate, sealing ring and pole structure, ensuring the stability and sealing of the assembled structure, thereby improving the reliability of the battery.

[0013] In an optional embodiment, the pole hole further includes a limiting section, the lower end of the limiting section is flush with the upper end of the riveted section, the limiting section is runway-shaped, and the outline of the limiting section is larger than the outline of the riveted section, and an annular support surface is formed between the outline line of the lower end of the limiting section and the outline line of the upper end of the riveted section, and the annular width of the support surface is W0, wherein W0 and t satisfy the relationship: 0.2≤t / W0≤0.6.

[0014] Beneficial effects: It can reduce the difficulty of processing and manufacturing the avoidance space, ensure the smooth molding of the cover plate, and ensure that there is a sufficient sealing area between the cover plate and the sealing ring, thereby ensuring the sealing of the cover plate assembly.

[0015] In an optional embodiment, the ring width W0 of the support surface has a value range of: 0.3 mm ≤ W0 ≤ 0.7 mm.

[0016] Beneficial effects: It can ensure that the avoidance space can provide sufficient expansion space for the pole, ensure the consistency of the width of the cover plate after riveting, and ensure that the pole can meet the minimum push-pull force requirements. It can also avoid that the pole hole reserves too much expansion space for pole riveting, thereby avoiding excessive gap between the second column part of the pole and the riveting block, and ensuring smooth welding of the pole and the riveting block.

[0017] In an optional embodiment, along the width direction of the cover plate, the distance between the outer contour of the limiting section and the edge of the cover plate is W1, and the width of the cover plate is W2, wherein 0.15≤W1 / W2≤0.35.

[0018] Beneficial effect: By limiting the value of W1 / W2 to the range of 0.15 to 0.35, the pole hole has a reasonable proportion on the cover along the width direction, which can not only ensure that the cover has sufficient structural strength and avoid bending and deformation of the cover, but also ensure that the pole hole can be smoothly formed and the production qualification rate of the cover is guaranteed.

[0019] In an optional embodiment, the value range of W1 is: W1 ≥ 1.8 mm;

[0020] And / or, the value range of W2 is: W2≥12mm.

[0021] Beneficial effect: By limiting the distance W1 between the outer contour of the limiting section and the edge of the cover plate to be greater than or equal to 1.8 mm, the strength of the cover plate can be ensured to meet the requirements, bending and deformation of the cover plate can be avoided, and the reliability of the cover plate assembly can be improved;

[0022] By limiting the width W2 of the cover plate 1 to be greater than or equal to 12 mm, the manufacturing feasibility of the cover plate can be guaranteed, thereby ensuring the qualified rate in the cover plate production process and reducing the production cost.

[0023] In an optional embodiment, the cover plate assembly further includes a rivet block, which is arranged on one side of the cover plate, and a rivet hole corresponding to the pole hole is opened on the rivet block; the column further includes a second column portion, which is connected to one end of the first column portion, and the second column portion is passed through the rivet hole; the pole further includes a plate body, which is connected to the other end of the first column portion, and the plate body is located on the side of the cover plate away from the rivet block.

[0024] Beneficial effect: By arranging a rivet block on one side of the cover plate and a plate body of the pole on the other side, and at the same time arranging the first pole portion to pass through the pole hole on the cover plate, and the second pole portion to pass through the rivet hole on the rivet block, the pole can be riveted to the cover plate and the rivet block by riveting the pole, which has a simple structure, convenient operation and high reliability.

[0025] In a second aspect, the present invention further provides a battery comprising: a housing having an open end; an electrode group disposed within the housing; and the aforementioned cover plate assembly, the cover plate assembly being disposed to cover the open end of the housing. Because the battery includes the cover plate assembly, it has the same effects as the cover plate assembly and is not further described here. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 A top view of a cover plate assembly before riveting according to an embodiment of the present invention;

[0028] Figure 2 for Figure 1 Cross-sectional view in the middle BB direction;

[0029] Figure 3 for Figure 1 Cross-sectional view in CC direction;

[0030] Figure 4 This is a structural schematic diagram of a cover plate according to an embodiment of the present invention;

[0031] Figure 5 for Figure 4 A partial enlarged schematic diagram of G in the middle;

[0032] Figure 6 for Figure 4 A schematic structural diagram of the cover plate from another perspective is shown;

[0033] Figure 7 for Figure 4 a top view of the cover plate shown;

[0034] Figure 8 for Figure 7 The schematic diagram of a partial enlargement of the area where the pole hole is located on the cover plate shown;

[0035] Figure 9 for Figure 8 A local enlarged schematic diagram of J in FIG.

[0036] Figure 10 for Figure 7 Cross-sectional view in the HH direction;

[0037] Figure 11 This is a schematic structural diagram of a pole before riveting according to an embodiment of the present invention;

[0038] Figure 12 for Figure 11 The front view of the pole shown;

[0039] Figure 13 for Figure 11 A top view of the pole shown;

[0040] Figure 14 This is a schematic structural diagram of a sealing ring according to an embodiment of the present invention;

[0041] Figure 15 for Figure 14 A cross-sectional view of the sealing ring shown;

[0042] Figure 16 This is a top view of the cover plate assembly after riveting before improvement;

[0043] Figure 17 for Figure 16 Cross-sectional view in the FF direction;

[0044] Figure 18 for Figure 16 An exploded view of the cover assembly after riveting is shown;

[0045] Figure 19 This is a structural diagram of the cover before improvement;

[0046] Figure 20 for Figure 19 Cross-sectional view in the KK direction.

[0047] Description of reference numerals:

[0048] 1. Cover plate; 101. Avoidance space; 1011. First avoidance portion; 1012. Second avoidance portion; 102. Support surface; 110. Pole hole; 111. Riveted section; 1111. Arc surface; 1112. Rectangular surface; 1113. Inclined surface; 112. Limiting section; 120. Explosion-proof valve hole; 2. Riveted block; 201. Riveted hole; 202. First hole section; 203. Second hole section; 204. Third hole section; 3. Pole; 310. Column; 311. First column section; 312. Second column section; 320. Plate; 4. Sealing ring; 401. First ring section; 402. Second ring section; 5. First plastic part; 501. First through hole; 6. Second plastic part; 601. Second through hole; 7. Explosion-proof valve; 8. Explosion-proof patch. DETAILED DESCRIPTION

[0049] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0050] The cover plate assembly is a key component in the battery. Its function is to weld with the shell to form a sealed cavity, lead out the positive and negative electrodes of the electrode group, and serve as an assembly carrier. The traditional riveted cover plate consists of a cover plate, a riveted block, an upper plastic, a pole, a lower plastic, a sealing ring and other structures. In combination with the trend of lightweight structural parts and simplified structure, the cover plate of the blade battery is currently simplified from a double cylindrical pole to a runway-type single pole structure (such as Figure 16 (As shown). After the pole is riveted, the column expands radially. Since the blade cover is relatively narrow, the impact on the cover width is more pronounced. After riveting, the pole stretches the cover widthwise, causing the cover width to exceed tolerances. This, in turn, leads to difficulties in housing and cover assembly and increased welding defects. Therefore, it is crucial to address the issue of the cover width expanding and deforming due to the compression of the pole after riveting, resulting in excessive cover width.

[0051] The following combination Figures 1 to 20 , describing embodiments of the present invention.

[0052] According to an embodiment of the present invention, on the one hand, a cover plate assembly is provided, such as Figures 1 to 15As shown, the cover assembly includes: a cover 1, a pole 3 and a sealing ring 4. The cover 1 is provided with a pole hole 110, which includes at least a riveted section 111. The inner circumference of the riveted section 111 includes two arcuate surfaces 1111 arranged opposite to each other along the length direction, and two rectangular surfaces 1112 arranged opposite to each other along the width direction. Figure 8 As shown, the distance between the two rectangular surfaces 1112 along the width direction is E, and the diameter of the arc surface 1111 is D, wherein E>D, so as to form an avoidance space 101 on the riveted section 111; the pole 3 includes a column 310, and the column 310 includes a first column portion 311, which is inserted into the pole hole 110, and the size of the first column portion 311 along the width direction is A (as shown in FIG. Figure 13 As shown); among them, E, D and A satisfy the relationship: The sealing ring 4 is arranged between the pole 3 and the cover 1. Figure 8 The arrow in the middle refers to the "length direction"; the width direction refers to Figure 8 and Figure 13 The arrow in the middle points to the "width direction".

[0053] It should be noted that the cross section of the column 310 is runway-shaped, and the dimension A of the first column portion 311 along the width direction is the vertical distance between two straight line segments arranged oppositely in the runway-shaped contour line, that is, the dimension of the largest dimension of the first column portion 311 along the width direction is A; the cover plate assembly before the improvement is as follows Figures 16 to 18 As shown, the conventional cover plate 1 is as Figures 19 to 20 As shown, the pole hole thereon is a runway-shaped through hole. The pole hole 110 of this embodiment is an improvement on the traditional runway-shaped pole hole. The contour line of the orthographic projection of the traditional runway-shaped pole hole on the surface of the cover plate 1 includes arc segments relatively arranged along the length direction (orthographic projection of the arc surface 1111 on the surface of the cover plate 1), and a straight line segment connecting the two arc segments. The straight line segment is tangent to the arc segment. The vertical distance between the two straight line segments is equal to the diameter of the arc segment (i.e., the diameter D of the arc surface 1111). The avoidance space 10 of this embodiment 1 corresponds to at least a straight section of the runway-shaped pole hole. This straight section is recessed in a direction away from the center of the pole hole 110. After the recess, a rectangular surface 1112 is formed on the side away from the center of the pole hole 110. The distance E between the two rectangular surfaces 1112 opposite to each other in the width direction is greater than D, thereby increasing the opening area of ​​the riveted section 111 of the pole hole 110 and increasing the space for material expansion in the width direction when the pole 3 is riveted and deformed. The difference between E and D is the total size of the avoidance space 101 on both sides in the width direction.

[0054] Among them, along the width direction of the cover plate 1, avoidance spaces 101 are provided on both sides of the riveted section 111. That is, the depth of each avoidance space 101 is smaller than that of the conventional runway-type pole hole. Since a sealing ring 4 is provided between the pole hole 110 and the pole 3, the sealing ring 4 is pressed tightly between the pole 3 and the cover plate 1 to achieve sealing. The sealing ring 4 is elastic. Within the range that the sealing ring 4 can withstand, the greater the extrusion force it receives, the greater the elastic deformation and the larger the sealing area. If the value is greater than 0.1, the size of the avoidance space 101 in the width direction is relatively too large, and the extrusion force on the sealing ring 4 is too small, the contact area between the cover plate 1 and the sealing ring 4 is reduced, that is, the sealing area is reduced, and the risk of leakage of the cover plate assembly is increased; if If it is less than 0.05, the dimension of the avoidance space 101 along the width direction is relatively small, and the pole 3 severely squeezes the cover plate 1 after riveting and expansion, resulting in an excessive width of the cover plate 1 and poor width consistency of the cover plate 1.

[0055] The cover plate assembly of the present embodiment is applied, by setting the distance E between the two rectangular surfaces 1112 on the inner circumference of the riveted section 111 of the pole hole 110 to be greater than the diameter D of the curved surface 1111, so that an avoidance space 101 is formed on the riveted section 111, and the avoidance space 101 is reserved for the first column portion 311 of the pole 3 to expand during the riveting process, meeting the expansion demand of the first column portion 311, avoiding the first column portion 311 from excessively squeezing the riveted section 111 and causing the cover plate 1 to expand and deform in the width direction, thereby avoiding the width of the cover plate 1 from exceeding the tolerance, ensuring the consistency of the width of the cover plate 1 after riveting, and avoiding problems such as difficulty in assembling the shell cover and poor welding. In addition, by limiting the distance E between the two rectangular surfaces 1112, the diameter D of the curved surface 1111 and the dimension A of the first column portion 311 in the width direction to meet the requirements. The relationship formula is used to limit the concave size of the avoidance space 101 along the width direction to a reasonable range, which can ensure that the avoidance space 101 can provide sufficient space for material expansion, thereby ensuring the consistency of the width of the cover plate 1 after riveting, and can also avoid the reduction of the sealing area due to the extrusion pressure on the sealing ring 4 being too small, thereby ensuring the sealing of the cover plate assembly and improving the safety of the battery.

[0056] The following is a measurement of the width W2 of the cover plate 1 after riveting of different cover plate assemblies and the helium test sealing performance of the cover plate assembly. The measurement results of the embodiment and the comparative example are shown in Tables 1 to 3. Among them, for the cover plate assembly of the embodiment, E, D and A meet the requirements of this embodiment. The relationship between E, D and A of the cover assembly of the comparative example is not satisfied Wherein, W2 refers to the total size of the position on the cover plate 1 corresponding to the pole hole 110 along the width direction.

[0057] Table 1 shows the width dimension A of the first column portion 311 of the pole 3, which is 4 mm, and the diameter D of the arc surface 1111, which is 5 mm. The distance E between the two rectangular surfaces 1112 is taken into account for different values. The width W2 of the riveted cover plate 1 and the helium test sealing performance of the cover plate assembly are compared. The design value of the width W2 of the cover plate 1 is 15 mm, the width tolerance of the cover plate 1 is ±0.05 mm, and the helium leak rate is ≤1×10 -7 Pa.m 3 / s.

[0058] Table 1

[0059]

[0060]

[0061] Table 2 shows the width dimension A of the first column portion 311 of the pole 3 along the width direction = 4.4 mm, the diameter D of the arc surface 1111 = 5.5 mm, and the distance E between the two rectangular surfaces 1112 is taken into different values ​​to compare the width W2 of the riveted cover plate 1 and the helium test sealing performance of the cover plate assembly. Among them, the design value of the width W2 of the cover plate 1 is 16 mm, the width tolerance requirement of the cover plate 1 is ±0.05 mm, and the helium leak rate is ≤(1×10 -7 )Pa.m 3 / s.

[0062] Table 2

[0063]

[0064] Table 3 shows the width dimension A of the first column portion 311 of the pole 3 along the width direction = 5.2 mm, the diameter D of the arc surface 1111 = 6.5 mm, and the distance E between the two rectangular surfaces 1112 is set to different values ​​to compare the width W2 of the riveted cover plate 1 and the helium test sealing performance of the cover plate assembly. Among them, the design value of the width W2 of the cover plate 1 is 17.5 mm, the width tolerance requirement of the cover plate 1 is ±0.05 mm, and the helium leak rate is ≤ (1×10 -7 )Pa.m 3 / s.

[0065] Table 3

[0066]

[0067]

[0068] As can be seen from Table 1, in Examples 1-1 to 1-6, (ED) / 2A is within the range of 0.05 to 0.1 specified in this application, the width W2 of the cover plate 1 after riveting is within the range of 15±0.05 mm, and the helium leak detection rate is less than or equal to 1×10-7 Pa.m 3 / s, that is, the width of the cover plate 1 after riveting meets the tolerance requirements, the width of the cover plate 1 after riveting does not exceed the tolerance, the width consistency of the cover plate 1 is good, and the cover plate assembly passes the helium test, and the cover plate assembly has good sealing performance; while in Comparative Examples 1-1 and 1-2, (ED) / 2A is less than 0.05, which is not within the range specified in this application, although the helium leak rate is less than 1×10 - 7 Pa.m 3 / s, the helium test is qualified, but the width W2 of the cover plate 1 after riveting is greater than 15.05mm, which does not meet the tolerance requirement. The width of the cover plate 1 is out of tolerance and the width consistency is poor. In Comparative Examples 1-3 and 1-4, (ED) / 2A is greater than 0.1, which is not within the range defined in this application. Although the width W2 of the cover plate 1 after riveting meets the tolerance requirement of 15±0.05mm, the helium leak rate is greater than 1×10 -7 Pa.m 3 / s, helium test failed, and the sealing of the cover assembly did not meet the requirements.

[0069] It can be seen from Table 2 that in Examples 2-1 to 2-6, (ED) / 2A is within the range of 0.05 to 0.1 specified in this application, and the width W2 of the cover plate 1 after riveting is within the range of 16±0.05 mm, meeting the tolerance requirements. The cover plate 1 after riveting does not have a width deviation, the width consistency of the cover plate 1 is good, and the cover plate assembly passes the helium test, and the cover plate assembly has good sealing performance. In Comparative Examples 2-1 to 2-2, (ED) / 2A is less than 0.05, which is not within the range specified in this application. Although the helium leak rate is less than 1×10 -7 Pa.m 3 / s, the helium test is qualified, but the width W2 of the cover plate 1 after riveting is greater than 16.05mm, which does not meet the tolerance requirement. The width of the cover plate 1 is out of tolerance and the width consistency is poor. In Comparative Examples 2-3 and 2-4, (ED) / 2A is greater than 0.1, which is not within the range defined in this application. Although the width W2 of the cover plate 1 after riveting meets the tolerance requirement of 16±0.05mm, the helium leak rate is greater than 1×10 -7 Pa.m 3 / s, helium test failed, and the sealing of the cover assembly did not meet the requirements.

[0070] It can be seen from Table 3 that in Examples 3-1 to 3-6, (ED) / 2A is within the range of 0.05 to 0.1 specified in this application, and the width W2 of the cover plate 1 after riveting is within the range of 17.5±0.05 mm, meeting the tolerance requirements. The cover plate 1 after riveting does not have a width deviation, the width consistency of the cover plate 1 is good, and the cover plate assembly passes the helium test, and the cover plate assembly has good sealing performance. In Comparative Examples 3-1 to 3-2, (ED) / 2A is less than 0.05, which is not within the range specified in this application. Although the helium leak rate is less than 1×10 -7 Pa.m 3 / s, the helium test is qualified, but the width W2 of the cover plate 1 after riveting is greater than 17.55mm, which does not meet the tolerance requirement. The width of the cover plate 1 is out of tolerance and the width consistency is poor. In Comparative Examples 3-3 and 3-4, (ED) / 2A is greater than 0.1, which is not within the range defined in this application. Although the width W2 of the cover plate 1 after riveting meets the tolerance requirement of 17.5±0.05mm, the helium leak rate is greater than 1×10 -7 Pa.m 3 / s, helium test failed, and the sealing of the cover assembly did not meet the requirements.

[0071] In summary, when (ED) / 2A satisfies When the relationship is expressed as follows, the width and sealing performance of the cover plate 1 of the riveted cover plate assembly meet the requirements at the same time, and the performance of the cover plate assembly is better.

[0072] In one embodiment, a clearance space 101 is provided on each side of the riveted section 111 along the width direction. Each clearance space 101 includes at least a first clearance portion 1011 formed by recessing the straight segments of the racetrack-shaped through hole away from the center of the pole hole 110. The recessed depth of each first clearance portion 1011 is t, where t = (ED) / 2, and 0.1 mm ≤ t ≤ 0.5 mm. It should be noted that the pole hole 110 is a through hole extending vertically through the cover plate 1. A conventional racetrack-shaped pole hole has a runway-shaped outline, with the straight segments and arc segments of the runway-shaped through hole outline arranged tangent to each other. Correspondingly, the vertical distance between the two original rectangular surfaces is equal to the diameter D of the arc surface. In this embodiment, the first clearance portion 1011 is formed by recessing the original rectangular surfaces corresponding to the straight segments of the conventional racetrack-shaped through hole away from the center of the pole hole 110, thereby increasing the accommodation space of the pole hole 110 along the width direction. By setting a rivet section 111 with an avoidance space 101 on each side along the width direction, and each avoidance space 101 includes at least a first avoidance portion 1011 formed by the recess of the side wall corresponding to the straight section of the traditional runway-type through hole, the recess depth t of the first avoidance portion 1011 relative to the side wall of the traditional runway-type through hole along the width direction is half of the difference between the distance E between the two rectangular surfaces 1112 and the diameter D of the arc surface 1111, that is, the recess depths of the two first avoidance portions 1011 are equal, ensuring the symmetry of the avoidance space 101 on the pole hole 110 along the width direction, thereby ensuring the uniformity of the material expansion space provided by the avoidance space 101, avoiding the convex deformation of the other side of the cover plate 1 along the width direction due to insufficient material expansion space on one side during the riveting process of the pole 3, thereby ensuring the consistency of the width of the cover plate 1 after riveting, and avoiding the problem of excessive width of the cover plate 1.

[0073] Furthermore, if t is less than 0.1mm, the width of the avoidance space 101 is too small, the space provided for material expansion is too small, and it is difficult to process and form, making the cover plate 1 difficult to stamp and resulting in a high failure rate. If t is greater than 0.5mm, the width of the avoidance space 101 is too large, the contact surface between the cover plate 1 and the sealing ring 4 is insufficient, and the cover plate assembly has a poor seal. Therefore, by limiting the recessed depth t of each first avoidance portion 1011 to a value within the range of 0.1mm to 0.5mm, it is possible to ensure that the avoidance space 101 can provide sufficient space for material expansion, ensure the consistency of the width of the cover plate 1 after riveting, reduce the difficulty of stamping the cover plate 1, ensure the pass rate of the cover plate 1, and avoid insufficient contact surface between the cover plate 1 and the sealing ring 4, thereby ensuring the sealing of the cover plate assembly.

[0074] In one embodiment, further combined Figure 8As shown, the rectangular surface 1112 and the arc surface 1111 are connected by an inclined surface 1113, and the inclination angle of the inclined surface 1113 relative to the rectangular surface 1112 is θ, wherein 110°≤θ≤160°. It should be noted that the first avoidance portion 1011 is formed by the depression of the entire straight segment of the traditional runway-type through hole, that is, the size of the rectangular surface 1112 along the length direction is equal to the size of the straight segment of the traditional runway-type through hole along the length direction, and the inclined surface 1113 is a plane inclined relative to the rectangular surface 1112, and the inclined surface 1113 is parallel to the center line of the pole hole 110, and the inclined surface 1113 is located in the area covered by the arc segment of the traditional runway-type through hole, further combined with Figure 9 As shown, due to the presence of the inclined surface 1113, the arc length of the arc surface 1111 of this embodiment is shorter than the length of the arc segment (semicircle) of the traditional runway-type through hole, and a second avoidance portion 1012 is further added to the pole hole 110. The second avoidance portion 1012 is connected to the first avoidance portion 1011 and together constitutes the avoidance space 101, wherein the first avoidance portion 1011 and the second avoidance portion 1012 are divided as shown in FIG. Figure 9 As shown by the dotted line between the two arc-shaped surfaces 1111, the dotted line connecting the two arc-shaped surfaces 1111 corresponds to the outline of the traditional racetrack-type pole hole.

[0075] Therefore, by setting the rectangular surface 1112 and the curved surface 1111 to be connected by the inclined surface 1113, on the one hand, it is convenient for the processing and forming of the avoidance space 101, and on the other hand, it further increases the expansion space that can be provided by the avoidance space 101, thereby meeting the expansion demand of the first column part 311 of the pole 3 during the riveting process; if the inclination angle θ of the inclined surface 1113 relative to the rectangular surface 1112 is less than 110°, the inclination angle is too small, the corner is relatively sharp, and the sealing ring 4 is easily scratched during the assembly process; if θ is greater than 160°, the inclination angle is too large, which reduces the area of ​​the cover plate 1 compressing the sealing ring 4, which may cause poor sealing. Therefore, by limiting the inclination angle θ of the inclined surface 1113 relative to the rectangular surface 1112 to a value between 110° and 160°, it can avoid the corner between the rectangular surface 1112 and the curved surface 1111 being too sharp and scratching the sealing ring 4, and can also ensure that the cover plate 1 can provide sufficient compression for the sealing ring 4, thereby ensuring the sealing of the cover plate assembly.

[0076] In one embodiment, further combined Figures 14 and 15 As shown, the sealing ring 4 at least includes a first ring portion 401 sleeved on the outer peripheral side of the first column portion 311. The ring width of the first ring portion 401 is M, wherein M satisfies the relationship between D and A: It should be noted that the first ring portion 401 is located between the first column portion 311 and the cover plate 1. The cover plate 1, the sealing ring 4 and the pole 3 each have dimensional tolerances. There are assembly tolerances during the assembly process. The above formula The range is composed of the cumulative assembly tolerance and dimensional tolerance, specifically the positioning deviation between the riveting process pole structure and the cover 1, as well as the dimensional tolerances of the pole hole 110, the thickness M of the first ring portion 401 of the sealing ring 4, and the width A of the first column portion 311. A value between 0.15 mm and 0.6 mm can ensure smooth assembly of the cover plate 1, the sealing ring 4 and the terminal structure, ensure the stability and sealing of the assembled structure, and thus improve the reliability of the battery.

[0077] In one embodiment, the sealing ring 4 further includes a second ring portion 402 , which is connected to an end of the first ring portion 401 close to the plate body 320 . The second ring portion 402 is compressed between the cover plate 1 and the plate body 320 to further improve the sealing performance.

[0078] In one embodiment, further combined Figure 10 As shown, the pole hole 110 also includes a limiting section 112, the lower end of the limiting section 112 is flush with the upper end of the riveted section 111, the limiting section 112 is runway-shaped, and the outline of the limiting section 112 is larger than the outline of the riveted section 111, and the contour line of the lower end of the limiting section 112 and the contour line of the upper end of the riveted section 111 form an annular support surface 102, further combined with Figure 8 As shown, the ring width of the support surface 102 is W0, wherein W0 and t satisfy the relationship: 0.2≤t / W0≤0.6, and the units of t and W0 are both mm. Figure 10 The end in the direction of "down" indicated by the middle arrow is specifically the end of the limit section 112 close to the inside of the shell; the upper end refers to Figure 10 The end in the “upper” direction indicated by the middle arrow is specifically the end of the riveted section 111 facing the outside of the shell.

[0079] It should be noted that the opening area of ​​the riveted section 111 is relatively small, and a support surface 102 is formed on the end of the limiting section 112 close to the riveted section 111, which is used to cooperate with the convex ring on the lower side of the first plastic part 5; the annular support surface 102 includes a portion corresponding to the arcuate surface 1111 and a portion corresponding to the rectangular surface 1112. Since the portion of the support surface 102 corresponding to the rectangular surface 1112 is affected by the avoidance space 101, the ring width of the portion of the support surface 102 corresponding to the rectangular surface 1112 is smaller than the ring width of the portion corresponding to the arcuate surface 1111. The ring width W0 of the support surface 102 is the ring width of the portion of the support surface 102 corresponding to the arcuate surface 1111, that is, the size of the support surface 102 at the largest point along its ring width direction is W0. If t / W0 is less than 0.2, the proportion of the avoidance space 101 on the support surface 102 along the width direction is too small, making processing and manufacturing difficult; if t / W0 is greater than 0.6, the proportion of the avoidance space 101 on the support surface 102 along the width direction is too large, and the sealing area between the cover plate 1 and the sealing ring 4 is low, affecting the sealing performance.

[0080] Therefore, by limiting the value of t / W0 to the range of 0.2 to 0.6, the difficulty of processing and manufacturing the avoidance space 101 can be reduced, ensuring the smooth molding of the cover plate 1, and ensuring that there is sufficient sealing area between the cover plate 1 and the sealing ring 4, thereby ensuring the sealing of the cover plate assembly.

[0081] In one embodiment, the range of the ring width W0 of the support surface 102 is: 0.3mm≤W0≤0.7mm. It should be noted that the pole 3, as an important component in the battery, needs to be able to withstand a certain degree of push and pull force without damage, looseness or poor contact, so as to ensure the electrical connection reliability and mechanical stability of the battery during use; if W0 is less than 0.3mm, the ring width of the support surface 102 is too small. Correspondingly, due to the limitation of the size of the support surface 102, the size of the avoidance space 101 along the width direction is too small, resulting in the avoidance space 101 not being able to provide enough expansion space for the pole, and the pole push and pull force is reduced; if W0 is greater than 0.7mm, the pole hole 110 is too large for the pole riveting expansion space reserved for the pole. The pole 3 is insufficiently expanded, which leads to an excessively large gap between the second column portion 312 and the riveting block 2, making welding difficult. Therefore, by limiting the ring width W0 of the support surface 102 to a value between 0.3 mm and 0.7 mm, it can be ensured that the avoidance space 101 can provide sufficient expansion space for the pole, ensure the consistency of the width of the cover plate 1 after riveting, and ensure that the pole 3 can meet the minimum push-pull force requirements, and can also avoid the pole hole 110 reserving too much expansion space for pole riveting, thereby avoiding the gap between the second column portion 312 of the pole 3 and the riveting block 2 being too large, ensuring that the pole 3 and the riveting block 2 are smoothly welded.

[0082] In one embodiment, further combined Figure 8As shown, along the width direction of the cover plate 1, the distance between the outer contour of the limiting section 112 and the edge of the cover plate 1 is W1, and the width of the cover plate 1 is W2, wherein 0.15≤W1 / W2≤0.35, and the units of W1 and W2 are both mm. It should be noted that the opening contour of the limiting section 112 is runway-shaped, and W1 is the vertical distance between the straight segment of the runway-shaped opening contour and the side of the cover plate 1 adjacent to the straight segment. If W1 / W2 is greater than 0.35, it means that the pole hole 110 occupies too large a proportion of the width direction of the cover plate 1, and the size of the physical part of the cover plate 1 corresponding to the pole hole 110 along the width direction is too small, and the cover plate 1 is prone to bending and deformation; if W1 / W2 is less than 0.15, the pole hole 110 occupies too small a proportion of the width direction of the cover plate 1, making punching difficult. Therefore, by limiting W1 / W2 to a value within the range of 0.15 to 0.35, the pole hole 110 has a reasonable proportion on the cover plate 1 along the width direction, which can ensure that the cover plate 1 has sufficient structural strength to avoid bending and deformation of the cover plate 1, and can also ensure that the pole hole 110 can be smoothly formed, thereby ensuring the production qualification rate of the cover plate 1.

[0083] In one embodiment, W1 has a value range of W1 ≥ 1.8 mm. If W1 is less than 1.8 mm, the physical portion of the cover plate 1 corresponding to the terminal hole 110 along the width direction is too small, and the cover plate 1 lacks structural strength. Therefore, by limiting the distance W1 between the outer contour of the limiting section 112 and the edge of the cover plate 1 to be greater than or equal to 1.8 mm, the required strength of the cover plate 1 can be ensured, bending and deformation of the cover plate 1 can be avoided, and the reliability of the cover plate assembly can be improved.

[0084] In one embodiment, the value range of W2 is: W2 ≥ 12 mm. If W2 is less than 12 mm, the width of the cover plate 1 is too small, manufacturing feasibility is low, and it is difficult to ensure product qualification rate. Therefore, by limiting the width W2 of the cover plate 1 to be greater than or equal to 12 mm, the manufacturing feasibility of the cover plate 1 can be guaranteed, thereby ensuring the qualification rate during the production process of the cover plate 1 and reducing production costs.

[0085] In one embodiment, further combined Figure 3 As shown, the cover assembly also includes a rivet block 2, which is arranged on one side of the cover 1. The rivet block 2 is provided with a rivet hole 201 corresponding to the pole hole 110. The column 310 also includes a second column 312, which is connected to one end of the first column 311 and is inserted into the rivet hole 201. The pole 3 also includes a plate 320, which is connected to the other end of the first column 311 and is located on the side of the cover 1 away from the rivet block 2. Among them, one end and the other end of the first column 311 are along Figure 3The two ends are opposite to each other in the "upper and lower" directions indicated by the arrows. By arranging the rivet block 2 on one side of the cover plate 1 and the plate body 320 of the pole 3 on the other side, and arranging the first column portion 311 of the pole 3 to pass through the pole hole 110 on the cover plate 1 and the second column portion 312 to pass through the rivet hole 201 on the rivet block 2, the pole 3 can be riveted to the cover plate 1 and the rivet block 2 by riveting the pole 3. This has a simple structure, is easy to operate, and has high reliability.

[0086] In one embodiment, the rivet hole 201 includes a first hole segment 202, a second hole segment 203, and a third hole segment 204 connected sequentially from bottom to top. The opening area of ​​the first hole segment 202 is smaller than the opening area of ​​the second hole segment 203, and the opening area of ​​the second hole segment 203 is smaller than the opening area of ​​the third hole segment 204. Figure 3 As shown, along the up-down direction, the size of the second column portion 312 before riveting is equal to the sum of the sizes of the first hole segment 202 and the second hole segment 203, the upper surface of the second column portion 312 is flush with the upper end surface of the second hole segment 203, the circumferential size of the second hole segment 203 is larger than the circumferential size of the second column portion 312, and a gap is formed between the inner wall of the second hole segment 203 and the outer circumferential wall of the second column portion 312, and the gap is a material expansion space for the second column portion 312; further combined with Figure 17 As shown, after the pole 3 and the cover plate 1 are riveted, the portion of the second column portion 312 corresponding to the second hole section 203 expands outward to fill the expanded space, and the riveted second column portion 312 forms a Figure 17 The shape in the middle is formed, thereby realizing the riveting between the pole 3, the riveting block 2 and the cover 1. At the same time, the avoidance space 101 on the first column 311 can prevent the first column 311 from being compressed and expanding and excessively squeezing the cover 1 in the width direction. Figure 3 The arrow in the middle points to the direction of "up and down"; the upper surface and upper end face refer to Figure 3 The surface or end face in the direction of "up" indicated by the middle arrow.

[0087] In one embodiment, the cover plate assembly further includes: a first plastic part 5 and a second plastic part 6, the first plastic part 5 is arranged between the riveting block 2 and the cover plate 1 to ensure insulation between the riveting block 2 and the cover plate 1, and a first through hole 501 corresponding to the pole hole 110 is opened on the first plastic part 5, and the first through hole 501 is for the portion of the first column portion 311 close to the second column portion 312 to pass through; the second plastic part 6 is arranged on the side of the cover plate 1 away from the first plastic part 5, and a second through hole 601 is opened on the second plastic part 6, and a partial section of the first column portion 311 close to the plate body 320 is passed through the second through hole 601, and the plate body 320 is located on the side of the second plastic part 6 away from the cover plate 1. The plate body 320 presses the second plastic part 6 toward the cover plate 1, and the second plastic part 6 is used to ensure insulation between the cover plate 1 and the pole group.

[0088] In one embodiment, the first plastic part 5 is an upper plastic and the second plastic part 6 is a lower plastic.

[0089] In one embodiment, the cover plate assembly further includes an explosion-proof valve 7. An explosion-proof valve hole 120 is further provided on the cover plate 1. The explosion-proof valve 7 is disposed in the explosion-proof valve hole 120. The explosion-proof valve 7 is adapted to open when the air pressure inside the battery reaches a preset value, thereby discharging high-temperature flue gas in the battery in a timely manner to prevent the battery from exploding. An explosion-proof patch 8 is affixed to the explosion-proof valve 7 to protect the explosion-proof valve.

[0090] The cover plate assembly of the present embodiment is optimized on the existing cover plate structure, and the expansion space is appropriately increased along the width direction on the riveted section 111 of the pole hole 110, which solves the problem that the middle area corresponding to the pole 3 on the current riveted cover plate is easily compressed and deformed, resulting in the abnormal expansion and deformation of the cover plate 1 along the width direction and out-of-tolerance after riveting, and can avoid the problem of the sealing ring 4 being squeezed and failing, thereby improving the yield rate of the cover plate assembly.

[0091] According to another aspect of an embodiment of the present invention, a battery is provided, comprising: a housing, an electrode group, and the aforementioned cover plate assembly. The housing has an open end; the electrode group is disposed within the housing; and the cover plate assembly covers the open end of the housing. Preferably, the battery is a lithium battery, and is used in fields such as electric vehicles and energy storage.

[0092] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention. Such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A cover plate assembly, characterized in that: include: A cover plate is provided with a pole hole, the pole hole including at least a riveted section, the inner circumference of the riveted section including two arcuate surfaces arranged opposite to each other along the length direction, and two rectangular surfaces arranged opposite to each other along the width direction, the distance between the two rectangular surfaces along the width direction is E, and the diameter of the arcuate surface is D, wherein E>D, so as to form an avoidance space on the riveted section; The pole includes a column, the column including a first column portion, the first column portion is inserted into the pole hole, the dimension of the first column portion along the width direction is A, wherein E, D and A satisfy the relationship: A sealing ring is provided between the pole and the cover plate.

2. The cover plate assembly according to claim 1, wherein: An escape space is provided on each side of the riveted section along the width direction, and each of the escape spaces includes at least a first escape portion formed by a straight segment of the runway-shaped through hole being recessed in a direction away from the center of the pole hole. The recess depth of each first escape portion is t, where t=(ED) / 2, 0.1mm≤t≤0.5mm.

3. The cover plate assembly according to claim 1, wherein: The rectangular surface and the arc surface are connected by an inclined surface, and an inclination angle of the inclined surface relative to the rectangular surface is θ, wherein 110°≤θ≤160°.

4. The cover plate assembly according to claim 1, wherein: The sealing ring at least includes a first ring portion sleeved on the outer peripheral side of the first column portion, and the ring width of the first ring portion is M, wherein M, D, and A satisfy the relationship:

5. The cover plate assembly according to claim 2, wherein: The pole hole also includes a limiting section, the lower end of the limiting section is flush with the upper end of the riveted section, the limiting section is runway-shaped, and the outline of the limiting section is larger than the outline of the riveted section. An annular support surface is formed between the outline line of the lower end of the limiting section and the outline line of the upper end of the riveted section, and the annular width of the support surface is W0, wherein W0 and t satisfy the relationship: 0.2≤t / W0≤0.

6.

6. The cover plate assembly according to claim 5, wherein: The range of the ring width W0 of the support surface is: 0.3mm≤W0≤0.7mm.

7. The cover plate assembly according to claim 5, wherein: Along the width direction of the cover plate, the distance between the outer contour of the limiting section and the edge of the cover plate is W1, and the width of the cover plate is W2, wherein 0.15≤W1 / W2≤0.

35.

8. The cover plate assembly according to claim 7, wherein: The value range of W1 is: W1 ≥ 1.8 mm; And / or, the value range of W2 is: W2≥12mm.

9. The cover plate assembly according to any one of claims 1 to 8, characterized in that: The cover plate assembly further includes a rivet block, which is arranged on one side of the cover plate and has a rivet hole corresponding to the pole hole; The column further includes a second column portion, the second column portion is connected to one end of the first column portion, and the second column portion is inserted into the rivet hole; The pole further includes a plate body connected to the other end of the first column portion, and the plate body is located on a side of the cover plate away from the riveting block.

10. A battery, characterized in that: include: a housing having an open end; a pole group, disposed in the housing; The cover plate assembly according to any one of claims 1 to 9, wherein the cover plate assembly is covered on the open end of the shell.

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