Pole structure, cover plate assembly and battery cell

Abstract

The invention relates to the technical field of batteries, and discloses a pole structure, a cover plate assembly and a battery cell. The pole structure comprises: a plate body; the column body comprises a first column part and a second column part, the first column part is fixedly connected between the plate body and the second column part, the second column part is suitable for being arranged in a riveting hole in the riveting block in a penetrating mode, and the second column part comprises two side parts oppositely arranged in the length direction and a main body part connected between the two side parts; in the width direction, the size of the side part is D, the size of the main body part is d, d is smaller than D, so that an avoiding space is formed on at least one side of the second column part in the width direction, and (D-d) / D is larger than or equal to 0.05 and smaller than or equal to 0.1. Therefore, it is guaranteed that the avoiding space can provide enough material expanding space for the second column part, the consistency of the width of the riveting block after riveting is guaranteed, welding difficulty at the joint of the second column part and the riveting block can be avoided, and the welding quality between the pole structure and the riveting block is guaranteed.

Description

Technical Field

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

[0002] The cover assembly consists of a cover body, a rivet block, an upper plastic, a pole, a lower plastic, a sealing ring and other structures. The pole is inserted into the through hole on the cover body and the through hole on the rivet block, and the pole is riveted to the cover body through the rivet block. After riveting, the pole expands in a direction perpendicular to the axis of the pole, and the column section on the pole that matches the rivet block squeezes the rivet block in a direction away from the axis of the pole. The width of the rivet block is usually small. After the pole and the rivet block are riveted, the rivet block is squeezed outward by the pole, which can easily cause serious expansion and deformation of the rivet block in the width direction. The edge of the rivet block is propped outward by the pole, resulting in an excessive width of the rivet block and poor width consistency of the rivet block, which in turn makes it difficult to clamp the battery cell assembly. Summary of the Invention

[0003] In view of this, the present invention provides a pole structure, a cover plate assembly and a battery cell to solve the problem of poor width consistency of the riveted blocks after riveting.

[0004] In a first aspect, the present invention provides a pole structure, comprising: a plate body; a column body, comprising a first column portion and a second column portion, the first column portion being fixedly connected between the plate body and the second column portion, the second column portion being suitable for being inserted into a rivet hole on a rivet block, the second column portion comprising two side portions arranged opposite to each other along a length direction, and a main body portion connected between the two side portions; along the width direction, the size of the side portion is D, and the size of the main body portion is d, wherein d<D, so as to form an avoidance space on at least one side of the second column portion along the width direction, and 0.05≤(Dd) / D≤0.1.

[0005] Beneficial effect: By setting the second column portion of the pole structure to include two side portions arranged opposite to each other along the length direction and a main body portion connected between the two side portions, and the dimension d of the main body portion along the width direction is smaller than the dimension D of the side portion along the width direction, an escape space is formed on at least one side of the second column portion along the width direction, which is recessed toward the center line of the column body, and space is reserved for the second column portion to expand during the riveting process, thereby meeting the expansion demand of the second column portion, avoiding the second column portion from excessively squeezing the side wall of the rivet hole along the width direction to cause the rivet block width to exceed the tolerance, ensuring the consistency of the rivet block width after riveting, and avoiding the battery cell from being formed. The assembly clamp is difficult, and by limiting the ratio of the total dimension Dd of the avoidance space along the width direction to the dimension D of the side portion along the width direction to be in the range of 0.05 to 0.1, the recessed dimension of the avoidance space along the width direction is limited to a reasonable range, which not only ensures that the avoidance space can provide sufficient material expansion space for the second column portion, thereby ensuring the consistency of the width of the riveted block after riveting, but also avoids the difficulty in welding the joint between the second column portion and the riveted block after riveting due to the excessive size of the avoidance space along the width direction, thereby ensuring the welding quality between the pole structure and the riveted block, and ensuring the conductivity after welding.

[0006] In an optional embodiment, the dimension D of the side portion along the width direction is in the range of 4 mm ≤ D ≤ 20 mm.

[0007] Beneficial effect: limiting the width dimension of the second column portion to a reasonable range can ensure smooth processing and riveting of the pole structure, and can also ensure effective squeezing of the sealing ring by the plate body, thereby ensuring the sealing of the cover assembly.

[0008] In an optional embodiment, one avoidance space is provided on each side of the second column portion along the width direction, and a size of each avoidance space along the width direction is K, wherein K=(Dd) / 2.

[0009] Beneficial effect: By setting an avoidance space on both sides of the second column along the width direction, and the size of each avoidance space along the width direction is equal to half of the size difference between the side portion and the main body along the width direction, the two avoidance spaces are symmetrically arranged on both sides of the second column, so that the second column has reserved space for expansion on both sides along the width direction, ensuring that the rivet block will not be excessively squeezed on both sides along the width direction after the second column is expanded, thereby further ensuring that the side edges of the rivet block on both sides along the width will not expand and deform outward, further ensuring the consistency of the width of the rivet block.

[0010] In an optional embodiment, the orthographic projection of the first column portion on the plate body is runway-shaped, the orthographic projection of the side portion on the first column portion is semicircular, and the orthographic projection of the main body portion on the first column portion is rectangular.

[0011] Beneficial effect: By setting the first column portion to be runway-shaped, and the second column portion to be formed by adding recessed portions on both sides of the width direction on the basis of the runway-shaped structure, the entire column is further improved from the traditional runway-shaped structure. The runway-shaped structure can effectively increase the flow area of ​​the pole structure, and form avoidance space on both sides of the runway-shaped structure along the width direction, which meets the material expansion requirements of the pole structure and has higher reliability.

[0012] In a second aspect, the present invention further provides a cover plate assembly, comprising: a cover plate body having a pole hole defined therein; a rivet block disposed on one side of the cover plate body, the rivet block having a rivet hole corresponding to the pole hole defined therein; and the aforementioned pole structure, wherein the pole structure's plate body is located on a side of the cover plate body facing away from the rivet block, a first pole portion extending through the pole hole, and a second pole portion extending through the rivet hole. Because the cover plate assembly includes the pole structure, it has the same effects as the pole structure and will not be further described here.

[0013] In an optional embodiment, the rivet hole includes a first hole segment and a second hole segment, the first hole segment is connected to one end of the second hole segment close to the cover plate body, the first hole segment and the second hole segment have the same shape, and the opening area of ​​the first hole segment is smaller than the opening area of ​​the second hole segment.

[0014] Beneficial effect: By setting the opening area of ​​the first hole section of the rivet hole to be smaller than the opening area of ​​the second hole section, it is convenient to limit the position of the rivet block on the pole structure after riveting, thereby ensuring the riveting fixation of the pole structure, the rivet block and the cover plate body.

[0015] In an optional embodiment, the dimension of the first hole segment along the width direction is E, wherein E and D satisfy the relationship: 0.2 mm ≤ ED ≤ 0.5 mm.

[0016] Beneficial effects: It can ensure the smooth assembly of the pole structure and the riveted block, and avoid excessive positioning deviation between the pole structure and the riveted block, thereby ensuring the uniformity of the gap between the pole structure and the riveted block, ensuring the welding quality of the pole structure and the riveted block, thereby avoiding excessive resistance between the riveted block and the pole structure, and ensuring the performance of the battery cell.

[0017] In an optional embodiment, the rivet block includes a first rivet segment, and along the direction of the center line of the rivet hole, the size of the first rivet segment is larger than the size of the first hole segment, and the total size of the first rivet segment along the width direction is W, wherein the relationship between W and E satisfies the following equation: 0.4≤E / W≤0.7.

[0018] Beneficial effect: It can prevent the pole structure from being too small in the width direction, thereby ensuring that the pole structure can meet the push and pull force requirements, and can also ensure that the riveted block has sufficient structural strength, thereby avoiding warping after riveting and ensuring that the flatness meets the requirements.

[0019] In an optional embodiment, the cover plate assembly further includes: a first plastic part, which is arranged on a side of the cover plate body facing away from the plate body, and the first plastic part is located between the rivet block and the cover plate body, and the first plastic part is provided with a first through hole corresponding to the pole hole; a second plastic part, which is arranged on a side of the cover plate body facing away from the first plastic part, and the second plastic part is located between the plate body and the cover plate body, and the second plastic part is provided with a second through hole corresponding to the pole hole.

[0020] Beneficial effect: By arranging a first plastic part between the cover body and the rivet block, the insulation between the rivet block and the cover body is ensured. By arranging a second plastic part on the side of the cover body away from the first plastic part, on the one hand, the insulation between the plate body and the cover body can be ensured, and on the other hand, the insulation between the cover body and the pole group can also be ensured, thereby improving the reliability of the cover assembly.

[0021] In a third aspect, the present invention further provides a battery cell 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 over the open end of the housing. Because the battery cell 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

[0022] 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.

[0023] Figure 1 This is a schematic structural diagram of a pole structure according to an embodiment of the present invention;

[0024] Figure 2 for Figure 1 A top view of the pole structure shown;

[0025] Figure 3 for Figure 1 A front view of the pole structure shown;

[0026] Figure 4 A top view of a cover plate assembly before riveting according to an embodiment of the present invention;

[0027] Figure 5 for Figure 4 Cross-sectional view in the AA direction;

[0028] Figure 6 for Figure 4 Cross-sectional view in the middle BB direction;

[0029] Figure 7 A top view of a riveted cover plate assembly according to an embodiment of the present invention;

[0030] Figure 8 for Figure 7 Cross-sectional view in CC direction;

[0031] Figure 9 for Figure 7 An exploded view of the cover assembly after riveting is shown;

[0032] Figure 10 A top view of a riveting block according to an embodiment of the present invention;

[0033] Figure 11 for Figure 10 Cross-sectional view in the FF direction;

[0034] Figure 12 This is a schematic diagram of the pole structure before improvement;

[0035] Figure 13 for Figure 12 A top view of the pole structure is shown.

[0036] Description of reference numerals:

[0037] 1. Plate body; 2. Column; 201. Avoidance space; 210. First column; 220. Second column; 221. Side; 222. Main body; 3. Cover body; 301. Pole hole; 302. Explosion-proof valve hole; 4. Riveted block; 401. Riveted hole; 4011. First hole section; 4012. Second hole section; 4013. Third hole section; 410. First riveted section; 420. Second riveted section; 5. Sealing ring; 6. First plastic part; 601. First through hole; 7. Second plastic part; 701. Second through hole; 8. Explosion-proof valve; 801. Explosion-proof patch. DETAILED DESCRIPTION

[0038] 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.

[0039] The width dimensions of the cover plate body and the rivet block in the currently commonly used blade batteries are relatively small. The column section on the pole structure that cooperates with the rivet block is the riveted expansion section. After riveting, the material expands and stretches the rivet block, and then the rivet block stretches the plastic, causing the rivet block width to be out of tolerance, which makes it difficult to assemble and clamp the battery cells.

[0040] The following combination Figures 1 to 13 , describing embodiments of the present invention.

[0041] According to an embodiment of the present invention, on the one hand, a pole structure is provided, such as Figures 1 to 3 As shown, the pole structure includes: a plate body 1 and a column body 2. The column body 2 includes a first column portion 210 and a second column portion 220. The first column portion 210 is fixedly connected between the plate body 1 and the second column portion 220. The second column portion 220 is suitable for passing through the rivet hole 401 on the rivet block 4. The second column portion 220 includes two side portions 221 arranged opposite to each other along the length direction, and a main body portion 222 connected between the two side portions 221; along the width direction, the size of the side portion 221 is D, and the size of the main body portion 222 is d, wherein d<D, so as to form an avoidance space 201 on at least one side of the second column portion 220 along the width direction, and 0.05≤(Dd) / D≤0.1. The length direction refers to Figure 2 The arrow in the middle refers to the "length direction"; the width direction refers to Figure 2 The arrow in the middle points to the "width direction".

[0042] It should be noted that the pole structure of this embodiment is an improvement on the traditional pole structure. Figures 12 to 13 As shown, the cross-section of the second column portion 220 of the pole structure before the improvement is runway-shaped, and the side portion 221 is semicircular. The width dimension of the second column portion 220 is the diameter D of the semicircle. The avoidance space 201 of this embodiment is formed by a portion of the outer circumference of the second column portion 220 being recessed along the width direction and toward the axial direction of the column 2. The main body 222 is a solid portion corresponding to the avoidance space 201 along the width direction. The total width dimension of the avoidance space 201 is Dd, and the units of D and d are both mm. The second column portion 220 of the pole structure is inserted into the rivet hole 401 of the rivet block 4. The rivet hole 401 is a through hole on the rivet block 4. During the riveting process, the second column portion 220 expands in a direction away from the centerline of the column 2. The avoidance space 201 increases the space between the outer circumference of the second column portion 220 and the inner circumferential wall of the rivet hole 401, thereby reserving space for the expansion of the pole structure.

[0043] Among them, if (Dd) / D>0.1, the size of the avoidance space 201 along the width direction is too large, and the reserved space for expansion is too large, resulting in the size of the main body 222 along the width direction being too small, and the main body 222 not expanding enough along the width direction. There is a large gap between the second column 220 after riveting and the inner wall of the rivet hole 401, which makes it difficult to weld the joints between the pole structure and the riveted block 4 after riveting, and the conductivity between the pole structure and the riveted block is reduced; if (Dd) / D<0.05, the size of the avoidance space 201 along the width direction is too small, and the reserved space for expansion along the width direction is insufficient. The second column 220 after riveting expands along the width direction and squeezes the riveted block 4, causing the width of the riveted block 4 to be out of tolerance and the width consistency of the riveted block 4 to be poor.

[0044] The pole structure of this embodiment is applied, and the second column portion 220 of the pole structure includes two side portions 221 arranged opposite to each other along the length direction and a main body portion 222 connected between the two side portions 221, and the dimension d of the main body portion 222 along the width direction is smaller than the dimension D of the side portion 221 along the width direction, thereby forming an avoidance space 201 recessed toward the center line of the column 2 on at least one side of the second column portion 220 along the width direction, reserving space for the second column portion 220 to expand during the riveting process, thereby meeting the expansion demand of the second column portion 220, avoiding the second column portion 220 from excessively squeezing the side wall of the rivet hole 401 along the width direction, and ensuring that the width of the rivet block 4 after riveting is within the tolerance. Consistency is achieved, thereby avoiding difficulties in clamping the battery cell assembly, and by limiting the ratio of the total dimension Dd of the avoidance space 201 along the width direction to the dimension D of the side portion 221 along the width direction to be in the range of 0.05 to 0.1, the recessed dimension of the avoidance space 201 along the width direction is limited to a reasonable range, which not only ensures that the avoidance space 201 can provide sufficient expansion space for the second column portion 220, thereby ensuring the consistency of the width of the riveted block 4 after riveting, but also avoids the difficulty in welding the joint between the second column portion 220 and the riveted block 4 after riveting due to the excessive size of the avoidance space 201 along the width direction, thereby ensuring the welding quality between the pole structure and the riveted block 4, and ensuring the conductivity after welding.

[0045] In one embodiment, the width dimension D of the side portion 221 is within the range of 4 mm ≤ D ≤ 20 mm. It should be noted that the width dimension D of the side portion 221 is the maximum width dimension of the second column portion 220. If D is less than 4 mm, the width dimension of the second column portion 220 is too small, making it difficult to rivet the pole and increasing the difficulty of production and processing. If D is greater than 20 mm, the width dimension of the second column portion 220 is too large, not only making it difficult to rivet the pole and increasing the difficulty of production and processing, but also resulting in insufficient width of the portion of the plate 1 corresponding to the column 2 along the width direction. Since this portion is used to compress the sealing ring, the plate 1 does not have enough compression area for the sealing ring 5, affecting the sealing performance. Therefore, by limiting D to a value within the range of 4 mm to 20 mm and limiting the width dimension of the second column portion 220 to a reasonable range, the smooth processing and riveting of the pole structure can be ensured, and the effective compression of the sealing ring 5 by the plate 1 can be ensured, thereby ensuring the sealing performance of the cover plate assembly.

[0046] The following describes a cover plate assembly composed of pole structures with different values ​​of the clearance space 201. After riveting and welding the pole structure to the riveted block, the width W1 of the riveted block 4 and the resistance R between the riveted block 4 and the pole structure on the different cover plate assemblies were measured to verify the impact of different values ​​of (Dd) / D on the performance of the cover plate assembly. The measurement results of the embodiment and comparative example are shown in Tables 1 to 3. In the pole structure of the embodiment, D and d satisfy the relationship of 0.05≤(Dd) / D≤0.1 of this embodiment; in the pole structure of the comparative example, D and d do not satisfy the relationship of 0.05≤(Dd) / D≤0.1. W1 refers to the width dimension of the second riveted section 420 of the riveted block 4 at the position corresponding to the pole hole 301.

[0047] The D of the pole structure in Table 1 is a fixed value (D=5mm), and the design value of the width W1 of the rivet block 4 is 12mm. The requirements are: the tolerance of the rivet block width W1 is ±0.05mm, and the resistance R≤0.035mΩ; different values ​​of d and the corresponding pole structures with the value of (Dd) / D are listed, and the width W1 of the rivet block 4 and the resistance R between the rivet block 4 and the pole structure in the finished cover assembly are compared to see whether they meet the requirements.

[0048] Table 1

[0049] d(mm) D(mm) (Dd) / D W1(mm) R(mΩ) Example 1-1 4.75 5 0.050 12.05 0.019 Example 1-2 4.723 5 0.055 12.041 0.021 Examples 1-3 4.65 5 0.070 12.027 0.024 Examples 1-4 4.6 5 0.080 12.018 0.026 Examples 1-5 4.55 5 0.090 12.009 0.03 Examples 1-6 4.5 5 0.100 12.002 0.035 Comparative Example 1-1 4.91 5 0.018 12.07 0.016 Comparative Example 1-2 4.8 5 0.040 12.057 0.018 Comparative Examples 1-3 4.45 5 0.110 11.98 0.039 Comparative Examples 1-4 4.3 5 0.140 12.012 0.044

[0050] The D of the pole structure in Table 2 is a fixed value (D=5.5mm), and the design value of the width W1 of the rivet block 4 is 13mm. The requirements are: the tolerance of the rivet block width W1 is ±0.05mm, and the resistance R≤0.035mΩ; different values ​​of d and the corresponding pole structures with the value of (Dd) / D are listed, and the width W1 of the rivet block 4 and the resistance R between the rivet block 4 and the pole structure in the finished cover assembly are compared to see whether they meet the requirements.

[0051] Table 2

[0052]

[0053]

[0054] The D of the pole structure in Table 3 is a fixed value (D=6.5mm), and the design value of the width W1 of the rivet block 4 is 14mm. The requirements are: the tolerance of the rivet block width W1 is ±0.05mm, and the resistance R is ≤ 0.035mΩ. The pole structures with different d values ​​and corresponding (Dd) / D values ​​are listed, and the width W1 of the rivet block 4 and the resistance R between the rivet block 4 and the pole structure in the finished cover assembly are compared to see whether they meet the requirements.

[0055] Table 3

[0056] d(mm) D(mm) (Dd) / D W1(mm) R(mΩ) Comparative Example 3-1 6.34 6.5 0.025 14.072 0.011 Comparative Example 3-2 6.24 6.5 0.040 14.057 0.014 Example 3-1 6.175 6.5 0.050 14.05 0.0178 Example 3-2 6.09 6.5 0.063 14.042 0.0239 Example 3-3 6.005 6.5 0.076 14.032 0.0267 Examples 3-4 5.97 6.5 0.082 14.0224 0.0278 Examples 3-5 5.9 6.5 0.092 14.016 0.0332 Examples 3-6 5.85 6.5 0.100 14.988 0.035 Comparative Example 3-3 5.75 6.5 0.115 14.008 0.0399 Comparative Examples 3-4 5.615 6.5 0.136 14.013 0.046

[0057] As can be seen from Table 1, in Examples 1-1 to 1-6, (Dd) / D is within the range of 0.05 to 0.1 as defined in the present application, the width W1 of the riveted block after riveting is within the range of 12±0.05 mm, and the resistance R is less than or equal to 0.035 mΩ, that is, the width of the riveted block after riveting and the resistance between the riveted block and the pole structure meet the requirements, the riveted block after riveting does not have a width deviation, the width consistency of the riveted block is good, and the resistance between the riveted block and the pole structure is small, which meets the requirements; whereas in Comparative Examples 1-1 to 1-2, (Dd) / D is less than 0.05, which is not within the range defined in this application. Although the resistance R is less than 0.035mΩ, the width W1 of the riveted block after riveting is greater than 12.05mm (i.e., 12+0.05mm), the width of the riveted block is out of tolerance, and the width consistency is poor. In Comparative Examples 1-3 to 1-4, (Dd) / D is greater than 0.1, which is not within the range defined in this application. Although the width W1 of the riveted block after riveting is within the range of 12±0.05mm, the resistance R is greater than 0.035mΩ, and the resistance between the riveted block and the pole structure is too large, which does not meet the requirements.

[0058] As can be seen from Table 2, in Examples 2-1 to 2-6, (Dd) / D is within the range of 0.05 to 0.1 as defined in this application, the width W1 of the riveted block after riveting is within the range of 13±0.05 mm, and the resistance R is less than or equal to 0.035 mΩ, that is, the width of the riveted block after riveting and the resistance between the riveted block and the pole structure meet the requirements, the riveted block after riveting does not have a width deviation, the width consistency of the riveted block is good, and the resistance between the riveted block and the pole structure is small, which meets the requirements; whereas in Comparative Examples 2-1 to 2-2, (Dd) / D is less than 0.05, which is not within the range defined in this application. Although the resistance R is less than 0.035mΩ, the width W1 of the riveted block after riveting is greater than 13.05mm (i.e., 13+0.05mm), the width of the riveted block is out of tolerance, and the width consistency is poor. In Comparative Examples 2-3 to 2-4, (Dd) / D is greater than 0.1, which is not within the range defined in this application. Although the width W1 of the riveted block after riveting is within the range of 13±0.05mm, the resistance R is greater than 0.035mΩ, and the resistance between the riveted block and the pole structure is too large, which does not meet the requirements.

[0059] As can be seen from Table 3, in Examples 3-1 to 3-6, (Dd) / D is within the range of 0.05 to 0.1 as defined in this application, the width W1 of the riveted block after riveting is within the range of 14±0.05 mm, and the resistance R is less than or equal to 0.035 mΩ, that is, the width of the riveted block after riveting and the resistance between the riveted block and the pole structure meet the requirements, the riveted block after riveting does not have a width deviation, the width consistency of the riveted block is good, and the resistance between the riveted block and the pole structure is small, which meets the requirements; while in Comparative Examples 3-1 to 3-2, (Dd) / D is less than 0.05, which is not within the range defined in this application. Although the resistance R is less than 0.035mΩ, the width W1 of the riveted block after riveting is greater than 14.05mm (i.e., 14+0.05mm), the width of the riveted block is out of tolerance, and the width consistency is poor. In Comparative Examples 3-3 to 3-4, (Dd) / D is greater than 0.1, which is not within the range defined in this application. Although the width W1 of the riveted block after riveting is within the range of 14±0.05mm, the resistance R is greater than 0.035mΩ, and the resistance between the riveted block and the pole structure is too large, which does not meet the requirements.

[0060] In summary, when 0.05≤(Dd) / D≤0.1, the width of the riveted block after riveting and the resistance value between the riveted block and the pole structure meet the use requirements of the cover assembly, and the performance of the cover assembly is good.

[0061] In one embodiment, a clearance space 201 is provided on each side of the second column 220 along the width direction, and the dimension of each clearance space 201 along the width direction is K, where K = (Dd) / 2. By providing a clearance space 201 on each side of the second column 220 along the width direction, and the dimension of each clearance space along the width direction is equal to half of the difference between the width dimensions of the side portion 221 and the main body 222 along the width direction, the two clearance spaces 201 are symmetrically arranged on both sides of the second column 220, thereby allowing for expansion space to be reserved on both sides of the second column 220 along the width direction. This ensures that after the second column 220 expands, the two sides along the width direction will not cause excessive extrusion on the rivet block 4, thereby further ensuring that the side edges of the rivet block 4 along both sides of the width will not expand and deform outward, further ensuring the consistency of the width of the rivet block 4.

[0062] In one embodiment, further combined Figure 2 As shown, the orthographic projection of the first column 210 on the plate 1 is runway-shaped, the orthographic projection of the side portion 221 on the first column 210 is semicircular, and the orthographic projection of the main body 222 on the first column 210 is rectangular. Figure 2 The dashed lines are for illustration only and do not actually exist. In reality, the side portion 221 and the main body 222 are integrally formed; the widthwise dimension D of the side portion 221 is the diameter of the semicircular shape of the side portion 221. It should be noted that the semicircular orthographic projection of the side portion 221 on the first column portion 210 and the rectangular orthographic projection of the main body 222 on the first column portion 210 indicate that the second column portion 220 is a further improvement of the racetrack-type pole. The side portions 221 are the arcuate areas on either side of the racetrack-type pole, and the main body 222 is a portion of the rectangular area in the middle of the racetrack-type pole. By recessing the rectangular surfaces on both sides of the rectangular area along the width direction and toward the centerline of the column 2, the recessed areas form the escape spaces 201. The remaining solid portion after the recessing is the main body 222. In other words, the entire straight section of the conventional racetrack-type pole structure is formed with the escape spaces 201.

[0063] Therefore, by setting the first column portion 210 to be runway-shaped, and the second column portion 220 to be formed by adding recessed portions on both sides of the width direction on the basis of the runway-shaped structure, the entire column 2 is further improved from the traditional runway-shaped structure. The runway-shaped structure can effectively increase the flow area of ​​the pole structure, and form avoidance space 201 on both sides of the runway-shaped structure along the width direction, which meets the material expansion requirements of the pole structure and has higher reliability.

[0064] According to an embodiment of the present invention, on the other hand, a cover plate assembly is provided. Figures 4 to 11As shown, the cover assembly includes: a cover body 3, a rivet block 4 and the above-mentioned pole structure. The cover body 3 is provided with a pole hole 301; the rivet block 4 is arranged on one side of the cover body 3, and a rivet hole 401 corresponding to the pole hole 301 is arranged on the rivet block 4; the plate body 1 of the pole structure is located on the side of the cover body 3 away from the rivet block 4, the first column portion 210 is passed through the pole hole 301, and the second column portion 220 is passed through the rivet hole 401. It should be noted that the rivet block 4 is arranged on the side of the cover body 3 facing the outside of the shell, and Figure 5 The plate body 1 is arranged on the side of the cover body 3 facing the inside of the shell, and Figure 5 The side in the direction of "down" indicated by the middle arrow; both the pole hole 301 and the rivet hole 401 are through holes. By providing the rivet block 4 on one side of the cover body 3 and the plate body 1 of the pole structure on the other side, and simultaneously providing the pole structure's column 2 to sequentially pass through the pole hole 301 on the cover body 3 and the rivet hole 401 on the rivet block 4, the riveting between the pole structure and the cover body 3 and the rivet block 4 is facilitated. Compared with the traditional cover structure, the deformation problem of the pole structure at the position corresponding to the second column portion 220 on the rivet block 4 caused by riveting pressure can be improved, thereby improving the production yield of the cover assembly.

[0065] In one embodiment, the rivet hole 401 includes a first hole section 4011 and a second hole section 4012. The first hole section 4011 is connected to the end of the second hole section 4012 close to the cover body 3. The first hole section 4011 and the second hole section 4012 have the same shape, and the opening area of ​​the first hole section 4011 is smaller than the opening area of ​​the second hole section 4012. Figure 5 As shown, before riveting, there are gaps between the second column 220 and the first hole section 4011 and the second hole section 4012, and the gap between the second column 220 and the second hole section 4012 is larger; further combined Figure 8 As shown, after riveting, the second column portion 220 expands in a direction away from the center line of the column body 2, thereby filling the gap between the second column portion 220 and the rivet hole 401, and the outer peripheral size of the column segment corresponding to the second hole segment 4012 on the second column portion 220 is larger than the outer peripheral size of the column segment corresponding to the first hole segment 4011, thereby limiting the downward movement of the column body 2 relative to the riveting block 4, and further combining with the plate body 1 to limit the upward movement of the pole structure relative to the cover body 3, thereby achieving relative fixation between the pole structure, the riveting block 4 and the cover body 3.

[0066] Therefore, by setting the opening area of ​​the first hole section 4011 of the rivet hole 401 to be smaller than the opening area of ​​the second hole section 4012, it is convenient to limit the position of the pole structure by the rivet block 4 after riveting, thereby ensuring the riveting fixation of the pole structure to the rivet block 4 and the cover body 3.

[0067] In one embodiment, the riveting hole 401 also includes a third hole segment 4013, and the third hole segment 4013 is connected to the end of the second hole segment 4012 away from the first hole segment 4011. The third hole segment 4013 has the same shape as the second hole segment 4012, and the opening area of ​​the third hole segment 4013 is larger than the opening area of ​​the second hole segment 4012. The size of the second column portion 220 in the up and down directions is equal to the sum of the sizes of the first hole segment 4011 and the second hole segment 4012 in the up and down directions. The upper surface of the second column portion 220 is flush with the upper end face of the second hole segment 4012. It should be noted that after the pole structure is riveted, the pole structure and the riveted block 4 need to be welded to reduce the internal resistance between the pole structure and the riveted block 4. Since the weld has a certain height, by setting the third hole segment 4013 with a larger opening area, a sink is formed on the upper surface of the riveted block 4, which can ensure that the weld does not exceed the surface of the riveted block 4. Among them, the up and down directions refer to Figure 5 and Figure 8 The arrow in the middle points to the direction of "up and down".

[0068] In one embodiment, further combined Figure 11 As shown, the dimension of the first hole segment 4011 along the width direction is E, where E and D satisfy the relationship: 0.2mm≤ED≤0.5mm. It should be noted that the opening contour line of the first hole segment 4011 is runway-shaped, and the dimension E of the first hole segment 4011 along the width direction is the vertical distance between the two straight segments of the runway-shaped contour, which is also equal to the diameter of the semicircle on both sides of the runway-shaped contour line; the difference between E and D is the assembly gap between the second column portion 220 and the first hole segment 4011. If ED is less than 0.2, the assembly gap between the pole structure and the riveted block 4 is insufficient, resulting in assembly difficulties; if ED is greater than 0.5, the positioning deviation between the pole structure and the riveted block 4 is too large, and the gap between the pole structure and the riveted block 4 is uneven, which is likely to cause poor welding during welding after riveting, thereby resulting in excessive resistance between the riveted block 4 and the pole structure after welding, affecting the performance of the battery cell.

[0069] Therefore, by limiting the difference between the dimension E of the first hole segment 4011 along the width direction and the dimension D of the side portion 221 along the width direction to a value within the range of 0.2 mm to 0.5 mm, it is possible to ensure smooth assembly of the pole structure and the riveted block 4, and to avoid excessive positioning deviation between the pole structure and the riveted block 4, thereby ensuring uniformity of the gap between the pole structure and the riveted block 4 and ensuring the welding quality of the pole structure and the riveted block 4, thereby avoiding excessive resistance between the riveted block 4 and the pole structure, and ensuring battery cell performance.

[0070] The following study used riveted blocks and pole structures with different ED values ​​to assemble cover plate assemblies, studying the effects of different assembly gaps on assembly results. The results of the Examples and Comparative Examples are shown in Tables 4 to 6. For the cover plate assemblies of the Examples, ED satisfied the relationship of 0.2 mm ≤ ED ≤ 0.5 mm; for the pole structures of the Comparative Example, ED did not satisfy the relationship of 0.2 mm ≤ ED ≤ 0.5 mm.

[0071] In Table 4, the D of the pole structure is a fixed value (D=5 mm), and the dimension E of the first hole section 4011 along the width direction is set to different values. The assembly conditions of the riveted block and the pole with different assembly gaps are compared, and the resistance value R between the riveted block 4 and the pole structure is required to be ≤0.035 mΩ.

[0072] Table 4

[0073] E(mm) D(mm) ED(mm) Is assembly difficult? R(mΩ) Example 4-1 5.2 5 0.200 no 0.0174 Example 4-2 5.278 5 0.278 no 0.0234 Example 4-3 5.34 5 0.340 no 0.0263 Example 4-4 5.4 5 0.400 no 0.029 Examples 4-5 5.45 5 0.450 no 0.0328 Examples 4-6 5.5 5 0.500 no 0.035 Comparative Example 4-1 5.1 5 0.100 yes / Comparative Example 4-2 5.15 5 0.150 yes / Comparative Example 4-3 5.54 5 0.540 no 0.0387 Comparative Example 4-4 5.62 5 0.620 no 0.043

[0074] In Table 5, the D of the pole structure is a fixed value (D=5.5 mm), and the dimension E of the first hole section 4011 along the width direction is set to different values. The assembly conditions of the riveted block and the pole with different assembly gaps are compared, and the resistance value R between the riveted block 4 and the pole structure is required to be ≤0.035 mΩ.

[0075] Table 5

[0076] E(mm) D(mm) ED(mm) Is assembly difficult? R(mΩ) Example 5-1 5.7 5.5 0.200 no 0.0169 Example 5-2 5.75 5.5 0.250 no 0.0216 Example 5-3 5.78 5.5 0.280 no 0.0266 Example 5-4 5.85 5.5 0.350 no 0.0289 Example 5-5 5.954 5.5 0.454 no 0.0329 Examples 5-6 6 5.5 0.500 no 0.035 Comparative Example 5-1 5.611 5.5 0.111 yes / Comparative Example 5-2 5.651 5.5 0.151 yes / Comparative Example 5-3 6.036 5.5 0.536 no 0.0397 Comparative Example 5-4 6.109 5.5 0.609 no 0.0433

[0077] In Table 6, the D of the pole structure is a fixed value (D=6.5 mm), and the dimension E of the first hole section 4011 along the width direction is set to different values. The assembly conditions of the rivet block and the pole with different assembly gaps are compared, and the resistance value R between the rivet block 4 and the pole structure is required to be ≤0.035 mΩ.

[0078] Table 6

[0079] E(mm) D(mm) ED(mm) Is assembly difficult? R(mΩ) Example 6-1 6.7 6.5 0.200 no 0.0164 Example 6-2 6.816 6.5 0.316 no 0.0214 Example 6-3 6.854 6.5 0.354 no 0.0283 Example 6-4 6.898 6.5 0.398 no 0.0297 Example 6-5 6.965 6.5 0.465 no 0.0338 Example 6-6 7 6.5 0.500 no 0.035 Comparative Example 6-1 6.608 6.5 0.108 yes / Comparative Example 6-2 6.625 6.5 0.125 yes / Comparative Example 6-3 6.608 6.5 0.108 no 0.0387 Comparative Example 6-4 6.608 6.5 0.108 no 0.0437

[0080] As can be seen from Table 4, in Examples 4-1 to 4-6, ED is within the range of 0.2 mm to 0.5 mm specified in this application. There is no difficulty in assembling the rivet block and the pole structure, and the resistance value R between the rivet block and the pole structure is less than or equal to 0.035 mΩ, which meets the requirements. In Comparative Examples 4-1 and 4-2, ED is less than 0.2 mm, which is outside the range specified in this application. The rivet block and the pole structure are difficult to assemble, and the cover plate assembly cannot be smoothly assembled. In Comparative Examples 4-3 and 4-4, ED is greater than 0.5 mm, which is outside the range specified in this application. Although there is no difficulty in assembling the rivet block and the pole structure, the resistance value R is greater than 0.035 mΩ. The resistance between the rivet block and the pole structure is too large and does not meet the requirements.

[0081] As can be seen from Table 5, in Examples 5-1 to 5-6, ED is within the range of 0.2 mm to 0.5 mm specified in this application. There is no difficulty in assembling the rivet block and the pole structure, and the resistance value R between the rivet block and the pole structure is less than or equal to 0.035 mΩ, which meets the requirements. In Comparative Examples 5-1 and 5-2, ED is less than 0.2 mm, which is not within the range specified in this application. The rivet block and the pole structure are difficult to assemble, and the cover plate assembly cannot be smoothly assembled. In Comparative Examples 5-3 and 5-4, ED is greater than 0.5 mm, which is not within the range specified in this application. Although there is no difficulty in assembling the rivet block and the pole structure, the resistance value R is greater than 0.035 mΩ. The resistance between the rivet block and the pole structure is too large and does not meet the requirements.

[0082] As can be seen from Table 6, in Examples 6-1 to 6-6, ED is within the range of 0.2 mm to 0.5 mm specified in this application. There is no difficulty in assembling the rivet block and the pole structure, and the resistance value R between the rivet block and the pole structure is less than or equal to 0.035 mΩ, which meets the requirements. In Comparative Examples 6-1 and 6-2, ED is less than 0.2 mm, which is outside the range specified in this application. The rivet block and the pole structure are difficult to assemble, and the cover plate assembly cannot be smoothly assembled and formed. In Comparative Examples 6-3 and 6-4, ED is greater than 0.5 mm, which is outside the range specified in this application. Although there is no difficulty in assembling the rivet block and the pole structure, the resistance value R is greater than 0.035 mΩ. The resistance between the rivet block and the pole structure is too large and does not meet the requirements.

[0083] In summary, when the assembly gap ED between the pole structure and the riveted block 4 is within the range of 0.2 mm to 0.5 mm, assembly can be successfully achieved, resistance requirements are met, and the cover assembly has good performance.

[0084] In one embodiment, further combined Figure 11As shown, the riveting block 4 includes a first riveting section 410. Along the direction of the center line of the riveting hole 401, the size of the first riveting section 410 is larger than the size of the first hole section 4011. The total size of the first riveting section 410 along the width direction is W, wherein W and E satisfy the relationship: 0.4≤E / W≤0.7. It should be noted that, as an important component in the battery cell, the pole structure needs to be able to withstand a certain degree of push-pull force without damage, looseness or poor contact, so as to ensure the electrical connection reliability and mechanical stability of the battery cell during use. If E / W is less than 0.4, the size of the first hole section 4011 along the width direction is too small. Correspondingly, the size of the second column portion 220 located on the inner side of the first hole section 4011 along the width direction is smaller, and the push-pull force that the pole structure can withstand does not meet the requirements; if E / W is greater than 0.7, the size of the first hole section 4011 along the width direction is too large, and the size of the remaining solid part of the first riveted section 410 along the width direction is too small, and the structural strength is insufficient, resulting in the riveted block 4 after riveting being warped on both sides along the width direction, poor flatness, and affecting the overall reliability of the cover assembly. Therefore, by limiting the total dimension W of the first riveted segment 410 along the width direction and the dimension E of the first hole segment 4011 along the width direction to satisfy the relationship of 0.4≤E / W≤0.7, it is possible to prevent the dimension of the pole structure along the width direction from being too small, thereby ensuring that the pole structure can meet the push and pull force requirements, and to ensure that the riveted block 4 has sufficient structural strength, thereby avoiding warping after riveting and ensuring that the flatness meets the requirements.

[0085] In one embodiment, the cover plate assembly further includes: a first plastic part 6 and a second plastic part 7. The first plastic part 6 is disposed on the side of the cover plate body 3 facing away from the plate body 1 and is located between the rivet block 4 and the cover plate body 3. The first plastic part 6 is provided with a first through hole 601 corresponding to the pole hole 301. The second plastic part 7 is disposed on the side of the cover plate body 3 facing away from the first plastic part 6 and is located between the plate body 1 and the cover plate body 3. The second plastic part 7 is provided with a second through hole 701 corresponding to the pole hole 301. By disposing the first plastic part 6 between the cover plate body 3 and the rivet block 4, insulation between the rivet block 4 and the cover plate body 3 is ensured. By disposing the second plastic part 7 on the side of the cover plate body 3 facing away from the first plastic part 6, insulation between the plate body 1 and the cover plate body 3 is ensured, and insulation between the cover plate body 3 and the pole group is ensured, thereby improving the reliability of the cover plate assembly.

[0086] In one embodiment, the first plastic part 6 is an upper plastic and the second plastic part 7 is a lower plastic.

[0087] In one embodiment, the riveting block 4 further includes a second riveting section 420 . The cross-sectional area of ​​the second riveting section 420 is larger than the cross-sectional area of ​​the first riveting section 410 , so as to facilitate assembly with the first plastic part 6 .

[0088] In one embodiment, the cover assembly further includes: a sealing ring 5 , which is disposed between the first column portion 210 and the pole hole 301 to ensure insulation between the first column portion 210 and the cover body 3 .

[0089] In one embodiment, the cover assembly further includes an explosion-proof valve 8, and an explosion-proof valve hole 302 is further opened on the cover body 3. The explosion-proof valve 8 is arranged in the explosion-proof valve hole 302. The explosion-proof valve 8 is suitable for opening when the air pressure inside the battery cell reaches a preset value, so as to timely discharge the high-temperature flue gas in the battery cell to prevent the battery cell from exploding; an explosion-proof patch 801 is affixed to the explosion-proof valve 8 to protect the explosion-proof valve.

[0090] The cover plate assembly of this embodiment improves the deformation and dimensional tolerance problems caused by squeezing the middle portion of the rivet block 4 corresponding to the column 2 after riveting the pole structure, by adding an avoidance space 201 with a total width Dd on the second column portion 220 that cooperates with the rivet block 4 on the pole structure, and limiting the correspondence between the total width of the avoidance space 201 and the maximum width of the second column portion 220, as well as the assembly relationship between the rivet block 4 and the pole structure, thereby improving the appearance yield of the cover plate assembly.

[0091] According to another aspect of an embodiment of the present invention, a battery cell, a housing, an electrode group, and the aforementioned cover plate assembly are also provided. The housing has an open end; the electrode group is disposed within the housing; and the cover plate assembly is disposed over the open end of the housing. Preferably, the battery cell is a lithium-ion battery cell for use in electric vehicles and energy storage applications.

[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 pole structure, characterized in that: include: plate body; The column comprises a first column portion and a second column portion, wherein the first column portion is fixedly connected between the plate body and the second column portion, the second column portion is adapted to be inserted into a rivet hole on a rivet block, and the second column portion comprises two side portions arranged opposite to each other along a length direction, and a main body portion connected between the two side portions; Along the width direction, the size of the side portion is D, and the size of the main portion is d, wherein d<D, so as to form an escape space on at least one side of the second column portion along the width direction, and 0.05≤(Dd) / D≤0.

1.

2. The pole structure according to claim 1, characterized in that: The dimension D of the side portion along the width direction has a value range of: 4 mm ≤ D ≤ 20 mm.

3. The pole structure according to claim 1, characterized in that: One escape space is provided on each side of the second column portion along the width direction. The size of each escape space along the width direction is K, where K=(Dd) / 2.

4. The pole structure according to any one of claims 1 to 3, characterized in that: The orthographic projection of the first column portion on the plate body is in a runway shape, the orthographic projection of the side portion on the first column portion is in a semicircular shape, and the orthographic projection of the main body portion on the first column portion is in a rectangular shape.

5. A cover plate assembly, characterized in that: include: The cover body is provided with a pole hole; A rivet block is provided on one side of the cover body, and a rivet hole corresponding to the pole hole is opened on the rivet block; The pole structure according to any one of claims 1 to 4, wherein the plate body of the pole structure is located on a side of the cover body away from the rivet block, the first column portion is inserted into the pole hole, and the second column portion is inserted into the rivet hole.

6. The cover plate assembly according to claim 5, wherein: The rivet hole includes a first hole segment and a second hole segment, the first hole segment is connected to one end of the second hole segment close to the cover plate body, the first hole segment and the second hole segment have the same shape, and the opening area of ​​the first hole segment is smaller than the opening area of ​​the second hole segment.

7. The cover plate assembly according to claim 6, wherein: The dimension of the first hole segment along the width direction is E, wherein E and D satisfy the relationship: 0.2 mm ≤ ED ≤ 0.5 mm.

8. The cover plate assembly according to claim 6, wherein: The rivet block includes a first rivet segment. Along the direction of the center line of the rivet hole, the size of the first rivet segment is larger than the size of the first hole segment. The total size of the first rivet segment along the width direction is W, wherein W and E satisfy the relationship: 0.4≤E / W≤0.

7.

9. The cover plate assembly according to claim 5, wherein: The cover plate assembly further comprises: a first plastic part, the first plastic part being disposed on a side of the cover body facing away from the plate body, and being located between the rivet block and the cover body, and having a first through hole corresponding to the pole hole; The second plastic part is arranged on a side of the cover body away from the first plastic part, and the second plastic part is located between the plate body and the cover body. The second plastic part is provided with a second through hole corresponding to the pole hole.

10. A battery cell, 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 5 to 9, wherein the cover plate assembly is covered on the open end of the shell.

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