Cover plate assembly and battery cell

Abstract

The invention relates to the technical field of batteries, and discloses a cover plate assembly and a battery cell. The cover plate assembly comprises: a cover plate provided with a pole hole; the riveting block is arranged on one side of the cover plate, the riveting block comprises a block body and a riveting hole penetrating through the block body, the riveting hole and the pole column hole are correspondingly arranged, first side walls are formed on the two sides of the block body in the width direction respectively, concave parts are arranged on the first side walls, and the concave parts and at least partial sections of the riveting hole are correspondingly arranged; and the pole comprises a pole body, the pole body comprises a rod part and a head part, the rod part is arranged in the pole hole in a penetrating manner, and the head part is arranged in the riveting hole in a penetrating manner. The avoiding space corresponding to the riveting hole is formed in the outer side wall of the riveting block, so that when the head of the pole is riveted and expanded to extrude the riveting hole, the solid part, corresponding to the riveting hole, on the block body can expand and deform towards the avoiding space, and the phenomenon that the block body expands and deforms excessively in the width direction and the width is out of tolerance is avoided; therefore, the consistency of the widths of the riveted blocks after riveting is ensured.

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 cell. Background Art

[0002] The cover assembly is composed of a cover body, a rivet block, an upper plastic, a pole, a lower plastic, a sealing ring and other structures. Among them, the rivet block is an important component of the cover assembly. A rivet through-hole is provided on the rivet block for the pole to pass through. The head of the pole is inserted into the rivet through-hole. After riveting, the pole expands in a direction perpendicular to the axis of the pole, and then the head of the pole squeezes the rivet block in a direction away from the axis of the pole. However, 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 deformation of the rivet block along the width direction. The edge of the rivet block is deformed by being supported 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 cover plate assembly and a battery cell to solve the problem of poor width consistency of the rivet blocks caused by deformation of the rivet blocks along the width direction after the cover plate assembly is riveted.

[0004] In a first aspect, the present invention provides a cover plate assembly, comprising: a cover plate, provided with a pole hole; a rivet block, arranged on one side of the cover plate, the rivet block comprising a block body and a rivet hole passing through the block body, the rivet hole being arranged corresponding to the pole hole, the block body being respectively formed with first side walls on both sides along the width direction, a recess being provided on the first side wall, the recess being arranged corresponding to at least a portion of the rivet hole; a pole, comprising a column, the column comprising a rod and a head, the rod being passed through the pole hole, and the head being passed through the rivet hole.

[0005] Beneficial effect: by arranging recessed portions on the first side walls on both sides of the rivet block in the width direction, and the recessed portions correspond to at least a partial section of the rivet hole, that is, an escape space corresponding to the rivet hole is formed on the outer side wall of the rivet block, then during the riveting process of the cover assembly, when the head of the pole is riveted to expand the material and squeeze the rivet hole, the solid part of the block body of the rivet block corresponding to the rivet hole can expand and deform into the escape space formed by the recessed portion, meeting the expansion demand of the rivet block along the width direction, and avoiding the phenomenon that the position corresponding to the rivet hole on the block body expands and deforms too much in the width direction and the width exceeds the tolerance when the head of the pole excessively squeezes the rivet hole, thereby ensuring the consistency of the rivet block width after riveting, thereby avoiding the difficulty of clamping the battery cell assembly and improving the reliability of the cover assembly.

[0006] 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, and the opening size of the first hole segment is smaller than the opening size of the second hole segment, and the size of the second hole segment along the width direction is N; the recessed portion forms a recessed bottom wall on one side close to the rivet hole along the width direction, the distance between the recessed bottom walls on the two first side walls along the width direction is a, and the distance between the two first side walls along the width direction is A; the size of the head along the width direction is D; wherein, A, a, N and D satisfy the relationship: 0.15≤(Aa) / (ND)≤0.3.

[0007] Beneficial effect: By limiting the value of (Aa) / (ND) within the range of 0.15 to 0.3, it is ensured that the recessed portion on the riveting block can provide a reasonable space for material expansion, which can prevent the riveting block width from exceeding the upper difference and the lower difference, thereby ensuring the consistency of the riveting block width after riveting.

[0008] In an optional embodiment, N and D satisfy the relationship: 0.8 mm ≤ ND ≤ 2 mm;

[0009] And / or, A and a satisfy the relationship: 0.08mm≤Aa≤0.8mm.

[0010] Beneficial effect: By limiting the ND value to the range of 0.8mm to 2mm, it can be ensured that the terminal has sufficient riveted expansion area after riveting, thereby ensuring that the riveted block can withstand sufficient tension and ensure the safety of the battery cell. It can also avoid the phenomenon of insufficient terminal expansion, thereby ensuring smooth welding between the terminal and the riveted block, ensuring welding quality, and ensuring good electrical conductivity between the terminal and the riveted block.

[0011] By limiting the value of Aa to the range of 0.08 mm to 0.8 mm, both the smooth formation of the recessed portion and the sufficient structural strength of the riveting block can be ensured.

[0012] In an optional embodiment, the distance a between the two recessed bottom walls along the width direction is in the range of: 8 mm ≤ a ≤ 40 mm;

[0013] And / or, the dimension N of the second hole segment along the width direction is in the range of: 4.8 mm ≤ N ≤ 35 mm;

[0014] And / or, the dimension D of the head along the width direction has a value range of: 4 mm ≤ D ≤ 33 mm.

[0015] Beneficial effect: By limiting the distance a between the two recessed bottom walls to a value within the range of 8 to 40 mm, the rivet block has a reasonable size along the width direction, which can not only achieve a smooth layout of the overall cover plate, but also avoid excessive weight of the rivet block, which is beneficial to improving the energy density of the battery cell;

[0016] By limiting the dimension N of the second hole segment in the width direction to a value within the range of 4.8 mm to 35 mm, the difficulty of arranging the cover plate assembly can be reduced, and the phenomenon of insufficient expansion of the pole can be avoided, thereby ensuring smooth welding between the pole and the riveted block, ensuring welding quality, and ensuring good electrical conductivity between the pole and the riveted block;

[0017] By limiting D to a value within the range of 4mm to 33mm and limiting the width dimension of the head to a reasonable range, it is convenient to control the shape and size of the riveting pit, and it can also avoid excessive material expansion due to the head being too large, thereby reducing the difficulty of riveting.

[0018] In an optional embodiment, the depth of each of the recessed portions along the width direction is (Aa) / 2;

[0019] And / or, the cross-section of the pole is runway-shaped, the opening contours of the first hole segment and the second hole segment are both runway-shaped, each of the first side walls is provided with a recessed portion, and the dimension of each recessed portion along the length direction is equal to the length of the straight segment of the runway-shaped contour line of the first hole segment.

[0020] Beneficial effect: By setting the depth of the two recessed portions in the width direction to be half of the difference between the distance A between the two first side walls and the distance a between the two recessed bottom walls, the two recessed portions are symmetrically arranged on both sides of the block body in the width direction, thereby ensuring the uniformity of the expansion space reserved on both sides of the riveting block in the width direction, avoiding the convex deformation of the other side of the riveted block due to insufficient expansion space on one side during the expansion process in the width direction when the pole is riveted, and further ensuring the consistency of the width of the riveted block after riveting;

[0021] By setting the pole as a runway-type pole, the cross-sectional area of ​​the pole can be increased, thereby increasing the current carrying capacity of the pole. At the same time, by setting each first side wall to have a recessed portion and the size of the recessed portion along the length direction being equal to the length of the straight segment of the contour line of the first hole segment, sufficient expansion space is reserved for the portion of the riveted block that is easily squeezed and deformed, thereby avoiding excessive width of the riveted block after riveting.

[0022] In an optional embodiment, the cover plate assembly further includes: a first plastic part, which is groove-shaped and includes a groove bottom and a groove side, the groove bottom is arranged between the riveted block and the cover plate, and the groove side is wrapped around the outer peripheral side of the riveted block.

[0023] Beneficial effect: By setting the first plastic part in a groove shape and the bottom of the groove being set between the riveted block and the cover plate, the insulation between the bottom surface of the riveted block and the cover plate can be ensured. At the same time, the side of the groove is wrapped around the outer peripheral side of the riveted block, which can insulate and protect the outer peripheral side of the riveted block, thereby further improving the safety of the riveted block.

[0024] In an optional embodiment, the riveting block further includes an annular ridge, which is located at one end of the block body away from the cover plate and is connected to the outer peripheral side of the block body; the inner peripheral wall of the groove side is stepped and forms a step surface facing away from the cover plate, and the ridge abuts against the step surface.

[0025] Beneficial effect: By providing an annular convex edge at the end of the rivet block away from the cover plate, and providing a step surface on the inner peripheral surface of the groove side of the first plastic part, the convex edge is supported by the step surface, thereby improving the positioning accuracy during the assembly process and the stability after assembly between the first plastic part and the rivet block.

[0026] In an optional embodiment, the vertical distance between the lower surface of the protruding edge and the lower surface of the block body is H1, the dimension of the recessed portion along the height direction is equal to H1, and the dimension of the first hole segment along the height direction of the riveting block is h1, wherein the difference between H1 and h1 is less than or equal to 0.5 mm.

[0027] Beneficial effect: By limiting the size of the recessed portion in the height direction to be equal to the vertical distance H1 between the lower surface of the convex edge and the lower surface of the block body, the processing and forming of the recessed portion is facilitated, and by limiting the difference between H1 and the size h1 of the first hole segment in the height direction of the riveted block to be less than or equal to 0.5 mm, it can be ensured that the recessed portion provides a reasonable expansion space for the expansion of the block body in the width direction, thereby avoiding the problem of width deviation of the riveted block after riveting.

[0028] In an optional embodiment, the dimension of the first hole segment along the height direction is h1, and the dimension of the second hole segment along the height direction is h2; a rivet pressing pit is formed on the pole after riveting, and the rivet pressing pit is located at the end of the head away from the rod portion, and the depth of the rivet pressing pit along the height direction is h3, wherein the relationship between h1, h2 and h3 satisfies: 0.6×h2≤h3≤(2mm+0.6×h1).

[0029] Beneficial effect: Ensuring that the pole has a suitable riveting size can ensure that the rivet hole can be filled after the pole is riveted, avoiding a large gap between the pole and the inner wall of the rivet hole, thereby ensuring that the resistance value between the rivet block and the pole is qualified, ensuring the safety of the battery cell during charging and discharging, and avoiding the rivet block from having a width error after riveting, thereby ensuring that the cover plate assembly size is qualified and the performance meets the use requirements.

[0030] In a second 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

[0031] 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.

[0032] Figure 1 A top view of a cover plate assembly before riveting according to an embodiment of the present invention;

[0033] Figure 2 for Figure 1 Cross-sectional view in CC direction;

[0034] Figure 3 for Figure 1 Cross-sectional view in the EE direction;

[0035] Figure 4 A top view of a riveting block before riveting according to an embodiment of the present invention;

[0036] Figure 5 for Figure 4 A top view of the riveted block is shown;

[0037] Figure 6 for Figure 5 Cross-sectional view in the FF direction;

[0038] Figure 7 This is a schematic structural diagram of a pole before riveting according to an embodiment of the present invention;

[0039] Figure 8 for Figure 7 A cross-sectional view of the pole shown;

[0040] Figure 9 This is a schematic structural diagram of a first plastic part according to an embodiment of the present invention;

[0041] Figure 10 A top view of a riveted cover plate assembly according to an embodiment of the present invention;

[0042] Figure 11 for Figure 10 Cross-sectional view in the GG direction;

[0043] Figure 12 for Figure 10 Exploded view of the cover assembly shown.

[0044] Description of reference numerals:

[0045] 1. Cover plate; 101. Pole hole; 102. Explosion-proof valve hole; 2. Riveted block; 200. Block body; 201. Recessed portion; 2011. Recessed bottom wall; 202. First side wall; 203. Raised edge; 210. Riveted hole; 211. First hole section; 212. Second hole section; 213. Third hole section; 3. Pole; 301. Riveted recess; 310. Column; 311. Rod; 312. Head; 320. Plate; 4. Sealing ring; 5. First plastic part; 501. Groove bottom; 502. Groove side; 503. Step surface; 504. First through hole; 6. Second plastic part; 601. Second through hole; 7. Explosion-proof valve; 8. Explosion-proof patch. DETAILED DESCRIPTION

[0046] 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.

[0047] The cover plate assembly is a key component in the battery cell. Its function is to weld with the shell to form a sealed cavity, lead out the positive and negative poles of the electrode group, and serve as an assembly carrier. The traditional riveted 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 width dimensions of the cover plate and the rivet block in the currently commonly used blade battery cells are relatively small. The head of the pole matches the rivet block. This column section is the riveted expansion section. After riveting, the riveted expansion section expands and stretches the rivet block, causing the width of the rivet block to exceed the tolerance. The rivet block stretches the upper plastic, making it difficult to clamp the battery cell assembly. Therefore, it is very important to solve the problem of the rivet block expanding and deforming along the width direction and the rivet block width exceeding the tolerance due to the extrusion of the pole after riveting.

[0048] The following combination Figures 1 to 12 , describing embodiments of the present invention.

[0049] According to an embodiment of the present invention, on the one hand, a cover plate assembly is provided, including: a cover plate 1, a rivet block 2 and a pole 3. The cover plate 1 is provided with a pole hole 101; the rivet block 2 is arranged on one side of the cover plate 1, and the rivet block 2 includes a block body 200 and a rivet hole 210 passing through the block body 200, and the rivet hole 210 is arranged corresponding to the pole hole 101, and the block body 200 is respectively formed with a first side wall 202 on both sides along the width direction, and a recessed portion 201 is provided on the first side wall 202, and the recessed portion 201 is arranged corresponding to at least a part of the section of the rivet hole 210; the pole 3 includes a column 310, and the column 310 includes a rod 311 and a head 312, the rod 311 is passed through the pole hole 101, and the head 312 is passed through the rivet hole 210. Among them, the width direction refers to Figure 4 and Figure 6 The middle arrow indicates the "width direction"; the corresponding arrangement of the rivet hole 210 and the pole hole 101 means that the center line of the rivet hole 210 coincides with the center line of the pole hole 101; the corresponding arrangement of the recessed portion 201 and the rivet hole 210 means that the orthographic projection of the rivet hole 210 on the first side wall and the area occupied by the recessed portion 201 on the first side wall at least partially coincide.

[0050] The cover plate assembly of this embodiment is applied, by providing recessed portions 201 on the first side walls 202 on both sides of the rivet block 2 in the width direction, and the recessed portions 201 correspond to at least a portion of the rivet hole 210, that is, an escape space corresponding to the rivet hole 210 is formed on the outer wall of the rivet block 2. During the riveting process of the cover plate assembly, when the head 312 of the pole 3 is riveted and presses the rivet hole 210, the solid portion of the block body 200 of the rivet block 2 corresponding to the rivet hole 210 can expand and deform into the escape space formed by the recessed portion 201, meeting the expansion requirement of the rivet block 2 along the width direction, and avoiding the phenomenon that the position corresponding to the rivet hole 210 on the block body 200 expands and deforms too much in the width direction and the width exceeds the tolerance when the head 312 of the pole 3 excessively squeezes the rivet hole 210, thereby ensuring the consistency of the width of the rivet block 2 after riveting, thereby avoiding the difficulty of clamping the battery cell assembly, and improving the reliability of the cover plate assembly.

[0051] It should be noted that the pole 3 also includes a plate 320, which is located on the side of the cover plate 1 away from the rivet block 2, and the outline of the positive projection of the plate 320 on the cover plate 1 is larger than the opening outline of the pole hole 101, then the plate 320 can limit the upward movement of the pole 3 relative to the cover plate 1; the pole hole 101 and the rivet hole 210 are both through holes, and the column 310 passes through the pole hole 101 and the rivet hole 210 in sequence. The rivet hole 210 includes a first hole section 211 and a second hole section 212. The first hole section 211 is a positioning section, and the second hole section 212 is a main material expansion section. The first hole section 211 is smaller than the second hole section 212 in both the length and width directions. Before riveting, there is a gap between the head 312 of the pole 3 and the inner wall of the riveting hole 210. After riveting, the head 312 expands in the direction away from the center line of the column 310 to fill the gap. At the same time, since the opening size of the second hole section 212 is larger than the opening size of the first hole section 211, the downward movement of the column 310 relative to the riveting block 2 can be restricted, thereby achieving relative fixation between the pole 3, the riveting block 2 and the cover plate 1 after riveting. Among them, the length direction refers to Figure 3 and Figure 4 The middle arrow points to the "length direction"; upward refers to the direction Figures 2 to 3 The arrow in the middle points to the direction of "up", and downwards means towards Figures 2 to 3 The arrow in the middle points to the direction of "down".

[0052] In one embodiment, the rivet hole 210 includes a first hole section 211 and a second hole section 212, the first hole section 211 is connected to the end of the second hole section 212 close to the cover plate 1, and the opening size of the first hole section 211 is smaller than the opening size of the second hole section 212, and the size of the second hole section 212 along the width direction is N; the recessed portion 201 forms a recessed bottom wall 2011 on one side close to the rivet hole 210 along the width direction, the distance between the recessed bottom walls 2011 on the two first side walls 202 along the width direction is a, and the distance between the two first side walls 202 along the width direction is A; the size of the head 312 along the width direction is D; wherein, A, a, N and D satisfy the relationship: 0.15≤(Aa) / (ND)≤0.3, and the units of A, a, N and D are all mm.

[0053] It should be noted that the recessed portion 201 is formed by a recessed portion of the first side wall 202. Before riveting, the gap nD between the head 312 of the pole 3 and the first hole segment 211 is smaller than the gap ND between the head 312 and the second hole segment 212. The head 312 is likely to cause excessive extrusion on the inner wall of the first hole segment 211 after riveting and swelling, causing the portion of the block body 200 corresponding to the first hole segment 211 to swell and deform due to excessive extrusion, thereby affecting the portion of the block body 200 corresponding to the second hole segment 212. corresponding part; Aa is the total size of the avoidance space formed by the recessed portion 201 along the width direction, ND is the total size of the expansion space reserved for the pole 3 in the second hole section 212 along the width direction, wherein, when the block body 200 is provided with recessed portions 201 on both sides along the width direction, Aa is the total size of the two recessed portions 201 along the width direction; when the block body 200 is provided with a recessed portion 201 on only one of the first side walls on both sides along the width direction, Aa is the size of the recessed portion 201 along the width direction.

[0054] If (Aa) / (ND) is less than 0.15, the size of the avoidance space formed by the recessed portion 201 along the width direction is insufficient, that is, the space reserved for expanding the material on the block body 200 is insufficient. After the head 312 of the pole 3 is riveted and the expanded material is squeezed out of the block body 200, the portion of the first side wall 202 of the block body 200 corresponding to the rivet hole 210 protrudes outward along the width direction, exceeding the original width of the riveted block 2 too much, causing the width of the riveted block 2 to exceed the upper difference; if (Aa) / (ND) is greater than 0.3, the size of the avoidance space formed by the recessed portion 201 along the width direction is too large, the space reserved for expanding the material on the block body 200 is too large, the expanded material on the block body 200 is insufficient, and the riveted block 2 still has obvious recessed parts on the side walls on both sides along the width direction after riveting, and the width of the riveted block 2 exceeds the lower difference.

[0055] Therefore, by limiting the value of (Aa) / (ND) within the range of 0.15 to 0.3, it is ensured that the recessed portion 201 on the riveting block 2 can provide a reasonable space for material expansion, which can prevent the width of the riveting block 2 from exceeding the upper difference and the lower difference, thereby ensuring the consistency of the width of the riveting block 2 after riveting.

[0056] In one embodiment, N and D satisfy the relationship: 0.8mm≤ND≤2mm. It should be noted that the distance between the second hole segment 212 and the head 312 is the main expansion space of the pole 3, and ND is the total size of the expansion space corresponding to the second hole segment 212 along the width direction. If ND is less than 0.8mm, the riveted expansion area of ​​the pole 3 after riveting is small, and the riveted block 2 can withstand less tension, affecting the safety of the battery cell; if ND is greater than 2mm, the main expansion space of the pole 3 provided by the riveted block 2 is too large, and it is very easy for the pole to be insufficiently expanded. There is a large gap between the pole 3 and the riveted block 2 after riveting, which makes it difficult to weld the joint between the pole 3 and the riveted block 2, and the conductivity between the pole 3 and the riveted block 2 is reduced.

[0057] Therefore, by limiting the value of ND to the range of 0.8mm to 2mm, it can be ensured that the pole 3 after riveting has sufficient riveting expansion area, thereby ensuring that the riveted block 2 can withstand sufficient tension and ensure the safety of the battery cell, and the phenomenon of insufficient pole expansion can be avoided, thereby ensuring smooth welding between the pole 3 and the riveted block 2, ensuring the welding quality, and ensuring good conductivity between the pole 3 and the riveted block 2.

[0058] In one embodiment, A and a satisfy the relationship: 0.08mm≤Aa≤0.8mm. If Aa is less than 0.08mm, the overall width dimension of the recessed portion 201 is too small, making machining difficult. If Aa is greater than 0.8mm, the overall width dimension of the recessed portion 201 is too large, resulting in a narrower remaining portion of the block body 200 corresponding to the recessed portion 201, affecting the overall strength of the riveted block 2. Therefore, by limiting Aa to a value between 0.08mm and 0.8mm, both smooth formation of the recessed portion 201 and sufficient structural strength of the riveted block 2 can be ensured.

[0059] In one embodiment, the distance a between the two recessed bottom walls 2011 along the width direction has a value range of: 8mm≤a≤40mm. The distance A between the two first side walls 202 is greater than the distance a between the two recessed bottom walls 2011. If a is less than 8mm, the dimension of the rivet block 2 along the width direction is too small, making the overall cover layout difficult; if a is greater than 40mm, the dimension of the rivet block 2 along the width direction is too large, making this solution unsuitable and eliminating the need for designing a clearance space. In addition, the rivet block 2 is too heavy, increasing the weight of the battery cell and hindering the improvement of the energy density of the battery cell. Therefore, by limiting the distance a between the two recessed bottom walls 2011 to a value within the range of 8 to 40mm, the rivet block 2 has a reasonable dimension along the width direction, which can not only achieve a smooth layout of the overall cover, but also avoid the rivet block 2 being too heavy, which is beneficial to improving the energy density of the battery cell.

[0060] In one embodiment, the dimension N of the second hole segment 212 along the width direction has a value range of: 4.8mm≤N≤35mm. If N is less than 4.8mm, the dimension of the second hole segment 212 along the width direction is too small. Accordingly, the dimension of the rivet block 2 along the width direction is too small, and the cover assembly is difficult to arrange. If N is greater than 35mm, the dimension of the second hole segment 212 along the width direction is too large, and the main expansion space of the pole 3 provided by the rivet block 2 is too large, making it difficult to fill the pole rivet expansion material, and insufficient pole expansion material is likely to occur. Therefore, by limiting the dimension N of the second hole segment 212 along the width direction to a value within the range of 4.8mm to 35mm, it is possible to reduce the difficulty of arranging the cover assembly and avoid the phenomenon of insufficient pole expansion material, thereby ensuring smooth welding between the pole 3 and the rivet block 2, ensuring welding quality, and ensuring good electrical conductivity between the pole 3 and the rivet block 2.

[0061] In one embodiment, the dimension D of the head 312 along the width direction has a value range of: 4mm≤D≤33mm. If D is less than 4mm, the dimension of the head 312 along the width direction is too small, which makes production and processing more difficult, and it is difficult to control the shape and size of the riveting pit 301; if D is greater than 33mm, the dimension of the head 312 along the width direction is too large, the amount of material expansion during pole riveting is too large, and pole riveting is difficult. Therefore, by limiting D to a value within the range of 4mm to 33mm, the dimension of the head 312 along the width direction is limited to a reasonable range, which not only facilitates the control of the shape and size of the riveting pit 301, but also avoids excessive expansion of the head 312 due to excessive size, thereby reducing the difficulty of riveting.

[0062] In one embodiment, the recessed depth of each recessed portion 201 along the width direction is (Aa) / 2. It should be noted that Aa is the total avoidance space formed by the two recessed portions 201 along the width direction. By setting the recessed depths of the two recessed portions 201 along the width direction to be half of the difference between the distance A between the two first side walls 202 and the distance a between the two recessed bottom walls 2011, the two recessed portions 201 are symmetrically arranged on both sides of the block body 200 along the width direction, thereby ensuring the uniformity of the expansion space reserved on both sides of the riveting block 2 along the width direction, avoiding the convex deformation of the other side of the riveting block 2 due to insufficient expansion space on one side during the expansion process in the width direction when the pole 3 is riveted, and further ensuring the consistency of the width of the riveting block 2 after riveting.

[0063] In one embodiment, the cross section of the pole 3 is runway-shaped, and the opening profiles of the first hole section 211 and the second hole section 212 are both runway-shaped. Each first side wall 202 is provided with a recessed portion 201, and the length of each recessed portion 201 along the length direction is equal to the length of the straight section of the runway-shaped outline of the first hole section 211. It should be noted that the cross section of the pole 3 refers to the orthographic projection of the pole 3 on the section perpendicular to its centerline; the length direction refers to Figure 4 The arrow in the middle indicates the "length direction." The orthographic projections of the opening contours of the first hole segment 211 and the second hole segment 212 on the cover plate 1 are concentrically arranged, with the major axis of the runway-shaped shape extending along the length direction and the minor axis extending along the width direction. The cross-section of the pole 3 is runway-shaped, and the cross-sections of both the rod 311 and the head 312 are runway-shaped. The cross-sectional area of ​​the rod 311 is larger than that of the head 312. The portion of the rod 311 that extends circumferentially beyond the head 312 forms a support platform, supporting the lower surface of the riveted block 2. The riveted hole 210 is configured to correspond to the head 312 of the pole 3. The portion of the block body 200 corresponding to the straight line of the runway-shaped second hole segment 212 is the location most susceptible to extrusion and deformation. By setting the pole 3 as a runway-type pole, the cross-sectional area of ​​the pole can be increased, thereby increasing the current carrying capacity of the pole 3. At the same time, by providing a recessed portion 201 on each first side wall 202 and the size of the recessed portion 201 along the length direction being equal to the length of the straight segment of the contour line of the first hole segment 211, sufficient expansion space is reserved for the portion of the riveted block 2 that is easily squeezed and deformed, thereby avoiding excessive width of the riveted block 2 after riveting.

[0064] In one embodiment, the cover plate assembly further includes: a first plastic part 5, which is in the shape of a groove and includes a groove bottom 501 and a groove side 502. The groove bottom 501 is arranged between the riveting block 2 and the cover plate 1, and the groove side 502 is wrapped around the outer peripheral side of the riveting block 2. It should be noted that the outer peripheral side refers to the circumferential side connected between the upper surface and the lower surface of the riveting block 2, wherein the upper surface refers to Figures 2 to 3 The surface in the direction of "up" indicated by the middle arrow is the surface of the riveting block 2 facing away from the cover plate 1; the lower surface refers to Figures 2 to 3 The surface in the "downward" direction indicated by the middle arrow is the surface of the riveted block 2 facing the cover plate 1. By providing the first plastic part 5 in a groove shape, with the groove bottom 501 disposed between the riveted block 2 and the cover plate 1, insulation between the bottom surface of the riveted block 2 and the cover plate 1 can be ensured. At the same time, the groove side 502 wraps around the outer periphery of the riveted block 2, providing insulation protection for the outer periphery of the riveted block 2 and further improving the safety of the riveted block 2.

[0065] In one embodiment, a first through hole 504 corresponding to the pole hole 101 is formed on the first plastic part 5 , and a portion of the rod portion 311 of the pole 3 close to the head portion 312 passes through the first through hole 504 .

[0066] In one embodiment, the riveting block 2 further includes an annular ridge 203, which is located at the end of the block body 200 away from the cover plate 1 and is connected to the outer peripheral side of the block body 200; the inner peripheral wall of the groove side portion 502 is stepped and has a step surface 503 facing away from the cover plate 1, and the ridge 203 abuts against the step surface 503. Specifically, the step surface 503 is set upward, and the lower surface of the ridge 203 abuts against the step surface 503, wherein upward refers to the direction toward Figures 2 to 3 The arrow in the middle points to the direction of "up"; the lower surface refers to Figures 2 to 3 The surface in the "downward" direction indicated by the middle arrow is the surface of the flange 203 facing the cover plate 1. By providing an annular flange 203 on the end of the riveting block 2 away from the cover plate 1 and providing a stepped surface 503 on the inner circumferential surface of the groove side portion 502 of the first plastic part 5, the flange 203 is supported by the stepped surface 503, thereby improving the positioning accuracy during assembly between the first plastic part 5 and the riveting block 2 and the stability after assembly.

[0067] In one embodiment, the upper surface of the ridge 203 is flush with the upper surface of the block body 200, and the boundary line between the ridge 203 and the block body 200 is as shown in FIG. Figure 6 As shown by the dashed line in FIG, it should be noted that the dashed line is only a schematic line. In reality, the flange 203 is integrally formed with the block body 200. The flange 203 is connected to the outer periphery of the block body 200. The width dimension of the block body 200 including the flange 203 is B, which is the maximum width dimension of the riveting block 2.

[0068] In one embodiment, the vertical distance between the lower surface of the convex edge 203 and the lower surface of the block body 200 is H1, the height dimension of the recessed portion 201 is equal to H1, and the height dimension of the first hole section 211 along the riveting block 2 is h1, wherein the difference between H1 and h1 is less than or equal to 0.5 mm. It should be noted that the height direction refers to Figure 6The "height direction" indicated by the middle arrow is in the same direction as the up-down direction; the difference between H1 and h1 is the difference between the size of the recessed portion 201 along the height direction and the size of the first hole segment 211 along the height direction of the riveting block 2. Specifically, H1 can be greater than h1, equal to h1, or less than h1, as long as the difference between the two is less than or equal to 0.5 mm. If the difference between H1 and h1 is greater than 0.5 mm, the expansion space provided by the recessed portion 201 may be insufficient or too large, and the width of the riveting block 2 after riveting may be difficult to control. By limiting the size of the recessed portion 201 in the height direction to be equal to the vertical distance H1 between the lower surface of the protruding edge 203 and the lower surface of the block body 200, the processing and forming of the recessed portion 201 is facilitated, and by limiting the difference between H1 and the size h1 of the first hole section 211 in the height direction of the riveted block 2 to be less than or equal to 0.5 mm, it can be ensured that the recessed portion 201 provides a reasonable expansion space for the block body 200 in the width direction, thereby avoiding the problem of width deviation of the riveted block 2 after riveting.

[0069] It should be noted that in the above embodiment, the recessed portion 201 and various parameters are the structure and parameters before riveting. After riveting, the block body 200 is deformed along the width direction to fill the recessed portion 201.

[0070] In one embodiment, the dimension of the first hole segment 211 along the height direction is h1, and the dimension of the second hole segment 212 along the height direction is h2; after riveting, a riveting pit 301 is formed on the pole 3, and the riveting pit 301 is located at the end of the head 312 away from the rod 311. The depth of the riveting pit 301 along the height direction is h3, wherein the relationship between h1, h2 and h3 satisfies the following equation: 0.6×h2≤h3≤(2mm+0.6×h1). It should be noted that the riveting equipment forms a rivet pressing pit 301 at the upper end of the pole 3, and squeezes the head 312 to expand the material in the direction away from the center line, thereby filling the gap between the pole 3 and the inner wall of the riveted hole 210. If h3 is less than 0.6×h2, there is a gap in the first hole section 211 and the material is insufficiently expanded. The resistance value between the riveted block 2 and the pole 3 is too large, causing the temperature to rise during charging and discharging, affecting safety; if h3 is greater than (2mm+0.6×h1), the pole 3 is riveted too deeply and the material is expanded too much, causing the riveted block 2 to be stretched and the width of the riveted block 2 to be out of tolerance. Therefore, by limiting the relationship between h1, h2 and h3 to 0.6×h2≤h3≤(2mm+0.6×h1), the pole 3 is ensured to have a suitable riveting size, which can ensure that the pole 3 can fill the rivet hole 210 after riveting, avoiding a large gap between the pole 3 and the inner wall of the rivet hole 210, thereby ensuring that the resistance value between the rivet block 2 and the pole 3 is qualified, ensuring the safety of the battery cell during charging and discharging, and avoiding the width of the rivet block 2 after riveting, thereby ensuring that the size of the cover assembly is qualified and the performance meets the use requirements.

[0071] In one embodiment, the rivet hole 210 further includes a third hole segment 213, which is connected to the end of the second hole segment 212 away from the first hole segment 211. The opening size of the third hole segment 213 is larger than the opening size of the second hole segment 212. It should be noted that after riveting, the upper surface of the head 312 is flush with the upper end surface of the second hole segment 212. It is necessary to weld the pole 3 and the rivet block 2. The welding position P is as shown in FIG. Figure 11 At the position indicated by the middle arrow, since the weld has a certain height, by setting the third hole section 213 on the upper side of the second hole section 212, and the third hole section 213 has a larger opening area, it can be ensured that the weld does not exceed the upper surface of the riveted block 2, thereby ensuring the neatness of the appearance of the cover assembly and ensuring the smooth welding of the subsequent bus on the cover assembly.

[0072] In one embodiment, the cover plate assembly further includes: a second plastic part 6, which is arranged on a 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. A partial section of the rod portion 311 of the pole 3 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.

[0073] In one embodiment, the first plastic part 5 is an upper plastic and the second plastic part 6 is a lower plastic.

[0074] In one embodiment, the cover plate assembly further includes: a sealing ring 4 , which is disposed between the rod portion 311 and the pole hole 101 to ensure sealing and insulation between the pole 3 and the cover plate 1 .

[0075] In one embodiment, the cover plate assembly further includes an explosion-proof valve 7, and an explosion-proof valve hole 102 is further opened on the cover plate 1. The explosion-proof valve 7 is arranged in the explosion-proof valve hole 102. The explosion-proof valve 7 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 8 is affixed to the explosion-proof valve 7 to protect the explosion-proof valve.

[0076] The following examples illustrate the effect of different values ​​of (Aa) / (ND) on the size of the pole after riveting. The measurement results of the embodiment and the comparative example are shown in Tables 1 to 3. Among them, the cover plate assembly of the embodiment satisfies the relationship of 0.15≤(Aa) / (ND)≤0.3; the cover plate assembly of the comparative example does not satisfy the relationship of 0.15≤(Aa) / (ND)≤0.3.

[0077] Case 1: The parameters of the cover assembly are A = 8 mm, N = 4.5 mm, D = 3.5 mm, and B = 8.5 mm. Different values ​​of a were used to verify whether the width of the riveted block after riveting met the tolerance requirement (B ± 0.1 mm). The test results are shown in Table 1. B is the maximum width dimension of the riveted block 2. The same principles apply to other cases and are not detailed here.

[0078] Table 1

[0079] A(mm) N(mm) a(mm) D(mm) (Aa) / (ND) B(mm) Example 1-1 8 4.5 7.85 3.5 0.15 8.6 Example 1-2 8 4.5 7.82 3.5 0.18 8.56 Examples 1-3 8 4.5 7.79 3.5 0.21 8.52 Examples 1-4 8 4.5 7.77 3.5 0.23 8.49 Examples 1-5 8 4.5 7.74 3.5 0.26 8.45 Examples 1-6 8 4.5 7.7 3.5 0.30 8.4 Comparative Example 1-1 8 4.5 7.9 3.5 0.10 8.66 Comparative Example 1-2 8 4.5 7.87 3.5 0.13 8.63 Comparative Examples 1-3 8 4.5 7.65 3.5 0.35 8.37 Comparative Examples 1-4 8 4.5 7.6 3.5 0.40 8.33

[0080] Case 2: The parameters of the cover assembly are A = 9 mm, N = 5 mm, D = 3.8 mm, and B = 9.5 mm. Different values ​​of a are used to verify whether the width of the riveted block after riveting meets the tolerance requirement (B ± 0.1 mm). The test results are shown in Table 2.

[0081] Table 2

[0082] A(mm) N(mm) a(mm) D(mm) (Aa) / (ND) B(mm) Example 2-1 9 5 8.82 3.8 0.15 9.6 Example 2-2 9 5 8.78 3.8 0.18 9.57 Example 2-3 9 5 8.75 3.8 0.21 9.52 Examples 2-4 9 5 8.71 3.8 0.24 9.48 Examples 2-5 9 5 8.68 3.8 0.27 9.43 Examples 2-6 9 5 8.64 3.8 0.30 9.4 Comparative Example 2-1 9 5 8.9 3.8 0.08 9.67 Comparative Example 2-2 9 5 8.86 3.8 0.12 9.64 Comparative Examples 2-3 9 5 8.62 3.8 0.32 9.36 Comparative Examples 2-4 9 5 8.79 3.8 0.18 9.32

[0083] Case 3: The parameters of the cover assembly are A = 9.5mm, N = 5.4mm, D = 4.1mm, and B = 10mm. Different values ​​of a are taken to verify whether the width of the riveted block after riveting meets the tolerance requirement (B ± 0.1mm). The test results are shown in Table 3.

[0084] Table 3

[0085]

[0086]

[0087] It can be seen from Tables 1 to 3 that in Examples 1-1 to 1-6, Examples 2-1 to 2-6, and Examples 3-1 to 3-6, (Aa) / (ND) are all within the range of 0.15 to 0.3 as defined in the present application, and the width B of the riveted blocks after riveting is within the tolerance range of B±0.1mm. The riveted blocks after riveting do not have a width deviation, and the width consistency of the riveted blocks is good; whereas in Comparative Examples 1-1 to 1-2, Comparative Examples 2-1 to 2-2, and Comparative Examples 3-1 to 3-2, (Aa) / (ND) are all less than The values ​​of (Aa) / (ND) are greater than 0.15, which is outside the range defined in the present application. The width B of the riveted blocks after riveting is greater than B+0.1mm, exceeding the upper limit, that is, the width of the riveted blocks exceeds the upper difference, and the width consistency of the riveted blocks is poor, which does not meet the requirements. In Comparative Examples 1-3 to 1-4, Comparative Examples 2-3 to 2-4, and Comparative Examples 3-3 to 3-4, (Aa) / (ND) are greater than 0.3, which is outside the range defined in the present application. The width B of the riveted blocks after riveting is less than B-0.1mm, exceeding the lower limit, that is, the width of the riveted blocks exceeds the lower difference, and the width consistency of the riveted blocks is poor, which does not meet the requirements.

[0088] In summary, when (Aa) / (ND) is within the range of 0.15 to 0.3, the width of the riveted block 2 after riveting is within the tolerance range, the width consistency of the riveted block is good, and meets the requirements.

[0089] In the cover plate assembly of this embodiment, the pole 3 adopts a runway-type pole. A recessed portion 201 is provided on the riveting block 2 before riveting. The recessed portion 201 is located on the side walls of the riveting block 2 on both sides along the width direction and corresponds to the riveting hole 210 to form an escape space. This improves the deformation and dimensional tolerance caused by the compression of the middle part of the riveting block 2 due to the riveting of the pole 3, thereby improving the appearance yield of the cover plate.

[0090] According to another aspect of an embodiment of the present invention, a battery cell 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 cell is a lithium-ion battery cell for use in electric vehicles, energy storage, and other fields.

[0091] 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 having a pole hole; a rivet block disposed on one side of the cover plate, the rivet block comprising a block body and a rivet hole extending through the block body, the rivet hole being disposed corresponding to the pole hole, the block body being respectively formed with first side walls on both sides along the width direction, the first side walls being provided with a recessed portion, the recessed portion being disposed corresponding to at least a portion of the rivet hole; The pole comprises a column body, wherein the column body comprises a rod portion and a head portion, the rod portion is inserted into the pole hole, and the head portion is inserted into the riveting hole.

2. The cover plate assembly according to claim 1, wherein: The rivet hole includes a first hole segment and a second hole segment, the first hole segment is connected to an end of the second hole segment close to the cover plate, and the opening size of the first hole segment is smaller than the opening size of the second hole segment, and the size of the second hole segment along the width direction is N; The recessed portion forms a recessed bottom wall on one side close to the rivet hole in the width direction, a distance a between the recessed bottom walls on the two first side walls in the width direction, and a distance A between the two first side walls in the width direction; The dimension of the head along the width direction is D; wherein A, a, N and D satisfy the relationship: 0.15≤(Aa) / (ND)≤0.

3.

3. The cover plate assembly according to claim 2, wherein: The relationship between N and D is: 0.8mm≤ND≤2mm; And / or, A and a satisfy the relationship: 0.08mm≤Aa≤0.8mm.

4. The cover plate assembly according to claim 2, wherein: The distance a between the two recessed bottom walls along the width direction is in the range of 8 mm ≤ a ≤ 40 mm; And / or, the dimension N of the second hole segment along the width direction is in the range of: 4.8 mm ≤ N ≤ 35 mm; And / or, the dimension D of the head along the width direction has a value range of: 4 mm ≤ D ≤ 33 mm.

5. The cover plate assembly according to claim 2, wherein: The depth of each of the recessed portions along the width direction is (Aa) / 2; And / or, the cross-section of the pole is runway-shaped, the opening contours of the first hole segment and the second hole segment are both runway-shaped, each of the first side walls is provided with a recessed portion, and the dimension of each recessed portion along the length direction is equal to the length of the straight segment of the runway-shaped contour line of the first hole segment.

6. The cover plate assembly according to claim 2, wherein: The cover plate assembly further includes: a first plastic part, which is groove-shaped and includes a groove bottom and a groove side. The groove bottom is arranged between the riveting block and the cover plate, and the groove side is wrapped around the outer periphery of the riveting block.

7. The cover plate assembly according to claim 6, wherein: The riveting block further includes an annular convex edge, which is located at an end of the block body away from the cover plate and connected to the outer peripheral side of the block body; The inner peripheral wall of the groove side portion is in a step shape and is formed with a step surface away from the cover plate, and the convex edge abuts against the step surface.

8. The cover plate assembly according to claim 7, wherein: The vertical distance between the lower surface of the convex edge and the lower surface of the block body is H1, the size of the recessed portion along the height direction is equal to H1, and the size of the first hole segment along the height direction of the riveting block is h1, wherein the difference between H1 and h1 is less than or equal to 0.5 mm.

9. The cover plate assembly according to any one of claims 2 to 8, characterized in that: The dimension of the first hole segment along the height direction is h1, and the dimension of the second hole segment along the height direction is h2; A rivet pressing pit is formed on the pole after riveting. The rivet pressing pit is located at the end of the head away from the rod. The depth of the rivet pressing pit along the height direction is h3, wherein h1, h2 and h3 satisfy the relationship: 0.6×h2≤h3≤(2mm+0.6×h1).

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 1 to 9, wherein the cover plate assembly is covered on the open end of the shell.

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