Pole, cover plate assembly and battery cell

Abstract

The invention relates to the technical field of batteries, and discloses a pole, a cover plate assembly and a battery cell. The pole comprises a plate body; the column body comprises a first column section and a second column section, the first column section is fixedly connected between the plate body and the second column section, the second column section is suitable for being arranged in a riveting hole in the riveting block in a penetrating mode, the second column section comprises two side parts oppositely arranged in the length direction and a middle part connected between the two side parts, and the side parts are flush with the lower surface of the middle part; the upper surfaces of the side parts protrude upwards out of the plane where the upper surface of the middle part is located. The second column section forms an unequal-height structural form, so that the size of the side part is increased, the material expansion quantity provided by the side part is increased, the phenomenon of insufficient material expansion of the side part after the pole column is riveted and pressed is avoided, and the phenomenon that the distance between the side part and the inner wall of the riveting hole is too large after the material expansion of the side part is avoided, so that the welding quality between the pole column and the riveting block is ensured; therefore, the riveting block can be in full contact with the pole, and the resistance value between the pole and the riveting block is prevented from being too large.

Description

Technical Field

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

[0002] The pole is a key component of the cover assembly. It forms part of the cover body, along with the rivet block, upper and lower plastic components, and a sealing ring. The pole's body is inserted sequentially through the pole hole in the cover body and the rivet hole in the rivet block. The rivet hole provides space for the pole to deform during riveting. During riveting, the pole is subjected to pressure from the rivet pin, causing it to expand and deform until it fits into the rivet hole, thereby securing the pole to the rivet block and cover body. At present, the pole structure on the cover assembly of the blade battery cell is simplified from the traditional double-cylindrical pole to a runway-type single pole. The cross-section of the runway-type pole consists of two semicircles and a straight edge connected between the two semicircles. There are differences in the riveting process of the straight edge and the semicircle at the top of the pole. The increase in the arc length of the semicircle part leads to insufficient material expansion, and the semicircle part does not fully fill the rivet hole, so that the gap between the semicircle part and the inner wall of the rivet hole is too large, resulting in poor welding such as cold welding and exploded points between the pole and the rivet block, resulting in poor contact between the rivet block and the pole, increased resistance, and affecting the charge and discharge performance of the battery cell. Summary of the Invention

[0003] In view of this, the present invention provides a pole, a cover plate assembly and a battery cell to solve the problem of uneven material expansion after the pole is riveted.

[0004] In a first aspect, the present invention provides a pole, comprising: a plate body; a column body, comprising a first column segment and a second column segment, the first column segment being fixedly connected between the plate body and the second column segment, the second column segment being adapted to be inserted into a rivet hole on a rivet block, the second column segment comprising two side portions arranged opposite to each other along a length direction, and a middle portion connected between the two side portions, the side portions being flush with a lower surface of the middle portion, and the upper surface of the side portions protruding upward from a plane where the upper surface of the middle portion is located.

[0005] Beneficial effect: By setting the two side portions of the second column segment that are relatively arranged along the length direction to be flush with the lower surface of the middle portion connected between the two side portions, and the upper surface of the side portion protruding upward from the plane where the upper surface of the middle portion is located, the second column segment forms a structural form with unequal heights, which increases the volume of the side portion, thereby increasing the amount of material expansion that the side portion can provide, avoiding the phenomenon of insufficient material expansion of the side portion after riveting the pole, and avoiding excessive distance between the side portion and the inner wall of the rivet hole after expansion, thereby ensuring the subsequent welding quality between the pole and the rivet block, so that the rivet block and the pole can be fully in contact, avoiding excessive resistance between the pole and the rivet block, thereby ensuring the charging and discharging performance of the battery cell.

[0006] In an optional embodiment, the upper surface of the side portion is inclined along the length direction, and along the length direction, the height of the side portion close to the middle portion is lower than the height of the side portion away from the middle portion.

[0007] Beneficial effect: By setting the upper surface of the side portion to be inclined relative to the upper surface of the middle portion, and the height of the side portion close to the middle portion is lower than the height of the side portion away from the middle portion, the height of the side portion gradually increases along the direction from the connection between the side portion and the middle portion to the direction from the side portion away from the middle portion, and a slope is formed on the upper side of the side portion, which conforms to the actual situation that the closer the side portion is to the circumferential edge of the second column segment, the more material expansion amount needs to be reserved, thereby avoiding the phenomenon of insufficient material expansion of the side portion after riveting.

[0008] In an optional embodiment, the orthographic projection of the second column segment on the plate body is runway-shaped, the orthographic projection of the side portion on the plate body is semicircular, and the radius of the semicircle is r, the difference between the maximum height of the side portion and the height of the middle portion is h, the rivet hole includes a rising section, and the opening profile of the rising section is runway-shaped, and the maximum dimension of the rising section along the width direction is d, wherein the relationship between h, d and r satisfies the following formula: 0.3≤h / (d / 2-r)≤0.6.

[0009] Beneficial effect: By limiting the relationship between h, d and r to 0.3≤h / (d / 2-r)≤0.6, it is possible to avoid insufficient material expansion on the side of the pole after riveting, and to avoid insufficient material expansion space reserved for the riveting hole due to excessive compensation height of the side material expansion, thereby ensuring smooth welding between the pole and the riveted block after riveting, ensuring welding quality, avoiding excessive resistance between the pole and the riveted block, and thus ensuring the charge and discharge performance of the battery cell.

[0010] In an optional embodiment, d and r satisfy the relationship: 0.3 mm ≤ d / 2 - r ≤ 1.5 mm.

[0011] Beneficial effect: It can ensure that there is sufficient connection strength between the pole and the riveted block after riveting, avoid the pole and the riveted block from being separated, thereby ensuring the reliability of the cover assembly, and avoid the phenomenon of insufficient pole expansion due to the reserved expansion space being too large, thereby further ensuring that the internal resistance between the pole and the riveted block is within a reasonable range, ensuring the charge and discharge performance of the battery cell.

[0012] In an optional embodiment, the difference h between the maximum height of the side portion and the height of the middle portion has a value range of: 0.05 mm ≤ h ≤ 0.8 mm.

[0013] Beneficial effects: It can not only reduce the processing difficulty and ensure the smooth processing and forming of the pole, but also reduce the welding difficulty between the pole and the riveted block after riveting, ensure the welding quality, and further avoid excessive resistance between the pole and the riveted block.

[0014] In an optional embodiment, the maximum dimension d of the expanding section along the width direction is in the range of: 4 mm ≤ d ≤ 20 mm;

[0015] And / or, the radius r of the semicircle formed by the orthographic projection of the side portion on the plate body has a value range of: 1.5 mm ≤ r ≤ 10 mm.

[0016] Beneficial Effects: By limiting the value of d to the range of 4mm to 20mm, the expansion section of the rivet hole is ensured to provide a reasonable expansion space. This can prevent the pole from excessively squeezing the riveted block after riveting, causing severe deformation and dimensional deviation of the riveted block. It can also ensure that the pole can fill the gap between the second pole section and the expansion section after riveting, thereby avoiding abnormal resistance between the pole and the riveted block.

[0017] By limiting r to a value within the range of 1.5 mm to 10 mm, the second column segment is ensured to have a reasonable size, which can not only ensure that the pole can smoothly form a riveted structure after riveting, but also ensure the connection strength between the pole and the riveted block after riveting, thereby ensuring the reliability of the cover plate assembly.

[0018] In an optional embodiment, the orthographic projection of the first column segment on the plate body is in a runway shape, and the circumferential dimension of the first column segment is greater than the circumferential dimension of the second column segment.

[0019] Beneficial effects: By setting the orthographic projections of the first column segment and the second column segment on the plate body in the up and down directions to be runway-shaped, the processing and forming of the column is facilitated, and it can be ensured that the pole has a larger flow area. In addition, by setting the circumferential dimension of the first column segment to be larger than the circumferential dimension of the second column segment, the smooth assembly of the pole, the cover plate body and the riveted block can be ensured.

[0020] 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; and the aforementioned pole, wherein the pole plate is located on a side of the cover plate body facing away from the rivet block, a first pole segment is inserted into the pole hole, and a second pole segment is inserted into the rivet hole. Because the cover plate assembly includes the pole, it has the same effects as the pole and will not be further described here.

[0021] In an optional embodiment, the riveting hole includes a positioning section and a rising section, the rising section is connected to the end of the positioning section away from the cover body, the opening contours of the positioning section and the rising section are both runway-shaped, and the opening size of the rising section is larger than the opening size of the positioning section.

[0022] Beneficial effect: By setting the opening size of the expansion section of the rivet hole larger than the opening size of the positioning 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 body.

[0023] 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

[0024] 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.

[0025] Figure 1 This is a schematic structural diagram of a pole before riveting according to an embodiment of the present invention;

[0026] Figure 2 for Figure 1 A top view of the pole shown;

[0027] Figure 3 for Figure 2 Cross-sectional view in the AA direction;

[0028] Figure 4 A top view of a cover plate assembly before riveting according to an embodiment of the present invention;

[0029] Figure 5 for Figure 4 Cross-sectional view in the middle BB direction;

[0030] Figure 6 for Figure 5 A partial enlarged schematic diagram of E in the middle;

[0031] Figure 7 for Figure 4 Cross-sectional view in CC direction;

[0032] Figure 8 A top view of a riveting block according to an embodiment of the present invention;

[0033] Figure 9 for Figure 8 Cross-sectional view in the FF direction;

[0034] Figure 10 A top view of a riveted cover plate assembly according to an embodiment of the present invention;

[0035] Figure 11 for Figure 10 Cross-sectional view in the MM direction;

[0036] Figure 12 for Figure 10 Exploded view of the cover assembly after riveting is shown.

[0037] Figure 13 This is a schematic diagram of the structure of a pole before riveting;

[0038] Figure 14 for Figure 13 The front view of the pole shown;

[0039] Figure 15 A top view of a cover plate assembly before riveting;

[0040] Figure 16 for Figure 15 Cross-sectional view in the GG direction;

[0041] Figure 17 for Figure 16 A partial enlarged schematic diagram of K in the middle;

[0042] Description of reference numerals:

[0043] 1. Plate body; 2. Column; 210. First column section; 220. Second column section; 221. Side portion; 222. Middle portion; 3. Cover body; 301. Pole hole; 302. Explosion-proof valve hole; 4. Riveting block; 401. Riveting hole; 4011. Positioning section; 4012. Material expansion section; 4013. Sinking 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

[0044] 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.

[0045] As lithium-ion battery technology matures, it's widely used as a power battery in electric vehicles and energy storage applications, leading to increasing demands for performance and safety. The lithium-ion battery cover is a key component in lithium-ion cells, welding to the shell to form a sealed cavity, extracting the positive and negative electrodes from the electrode assembly, and serving as an assembly carrier. The traditional cover riveting method consists of a cover assembly consisting of a rivet block, upper plastic, pole, cover body, lower plastic, sealing ring and other structures. Combined with the trend of lightweight structural parts and simplified structure, the current blade cover is simplified from a double-cylindrical pole to a single pole, and the pole column is a runway-shaped structure. Since the cross-section of the runway-shaped pole consists of two semicircles and a straight edge connected between the two semicircles, there is a difference in the riveting process of the straight edge and the semicircle at the top of the pole. The increase in the arc length of the semicircle part leads to insufficient material expansion, and the semicircle part does not fully fill the rivet hole, so that the gap between the semicircle part and the inner wall of the rivet hole is too large, resulting in poor welding such as cold welding and explosion points between the pole and the rivet block, resulting in poor contact between the rivet block and the pole, increased resistance, and affecting the charge and discharge performance of the battery cell.

[0046] The following combination Figures 1 to 17 , describing embodiments of the present invention.

[0047] According to an embodiment of the present invention, on the one hand, a pole is provided, such as Figures 1 to 3 As shown, the pole includes: a plate body 1 and a column body 2. The column body 2 includes a first column segment 210 and a second column segment 220. The first column segment 210 is fixedly connected between the plate body 1 and the second column segment 220. The second column segment 220 is suitable for passing through the rivet hole 401 on the rivet block 4. The second column segment 220 includes two side portions 221 arranged opposite to each other along the length direction, and a middle portion 222 connected between the two side portions 221. The side portions 221 are flush with the lower surface of the middle portion 222, and the upper surface of the side portion 221 protrudes upward from the plane where the upper surface of the middle portion 222 is located. The length direction refers to Figures 1 to 3 The middle arrow points to the "length direction"; the lower surface refers to Figure 3 The surface in the direction of "down" indicated by the middle arrow is the surface where the side portion 221, the middle portion 222 and the first column segment 210 are connected; the upper surface refers to Figure 3 The surfaces in the “upper” direction indicated by the middle arrow are surfaces on the side portion 221 and the middle portion 222 that are respectively away from the first column segment 210 .

[0048] It should be noted that the opening size of the rivet hole 401 is larger than the cross-sectional size of the second column segment 220. Before riveting, there is a gap between the inner wall of the rivet hole 401 and the outer peripheral surface of the second column segment 220. After riveting, the second column segment 220 expands in a direction away from the center line of the column 2 to fill the rivet hole 401. During the expansion process, the middle portion 222 mainly flows to both sides along the width direction, and the circumferential size of the side portion 221 increases. The side portion 221 flows outward in all directions perpendicular to the center line of the column 2, and the pole before the improvement is as follows. Figures 13 and 14 As shown, the upper surface of the second column section 220 is a plane. Conventional poles are prone to insufficient expansion of the side 221, and the expansion of the pole along the circumference is uneven. Outward refers to the direction away from the center line of the column 2; the width direction refers to the direction of the pole. Figures 1 to 2 The arrow in the middle points to the "width direction".

[0049] In the application of the pole of this embodiment, the two side portions 221 of the second column segment 220 that are arranged opposite to each other along the length direction are flush with the lower surface of the middle portion 222 connected between the two side portions 221, and the upper surface of the side portion 221 protrudes upward from the plane where the upper surface of the middle portion 222 is located, so that the second column segment 220 forms a structural form with unequal heights, which increases the volume of the side portion 221, thereby increasing the amount of material expansion that can be provided by the side portion 221, avoiding the phenomenon of insufficient material expansion of the side portion 221 after the pole is riveted, and avoiding excessive distance between the side portion 221 and the inner wall of the rivet hole 401 after expansion, thereby ensuring the subsequent welding quality between the pole and the rivet block 4, so that the rivet block 4 and the pole can be fully in contact, avoiding excessive resistance between the pole and the rivet block 4, thereby ensuring the charging and discharging performance of the battery cell.

[0050] In one embodiment, the upper surface of the side portion 221 is inclined along the length direction, and along the length direction, the height of the side portion 221 close to the middle portion 222 is lower than the height of the side portion 221 away from the middle portion 222. Figures 1 to 3 The arrow in the middle refers to the "length direction"; the height refers to the Figure 3 The dimension in the "up and down" direction indicated by the middle arrow. By setting the upper surface of the side portion 221 to be inclined relative to the upper surface of the middle portion 222, and the height of the side portion 221 close to the middle portion 222 being lower than the height of the side portion 221 away from the middle portion 222, the height of the side portion 221 gradually increases along the direction from the connection between the side portion 221 and the middle portion 222 to the direction of the side portion 221 away from the middle portion 222, and the upper side of the side portion 221 forms a slope, which conforms to the actual situation that the closer the side portion 221 is to the circumferential edge of the second column segment 220, the more material expansion needs to be reserved, thereby avoiding the phenomenon of insufficient material expansion of the side portion 221 after riveting.

[0051] Preferably, the height of the junction between the side portion 221 and the middle portion 222 is equal to the height of the middle portion 222. This allows for a smooth transition between the side portion 221 and the middle portion 222 on the upper surface of the second column segment 220. This facilitates the processing and forming of the pole, improves the stress response of the pole, and avoids significant corners that can lead to stress concentration. The height refers to the dimension along the vertical direction. Furthermore, along the circumference of the second column segment 220, there is a smooth transition between the side portion 221 and the middle portion 222.

[0052] In one embodiment, the orthographic projection of the second column section 220 on the plate body 1 is runway-shaped, the orthographic projection of the side portion 221 on the plate body 1 is semicircular, and the radius of the semicircle is r, the difference between the maximum height of the side portion 221 and the height of the middle portion 222 is h, the rivet hole 401 includes a rising section 4012, and the opening profile of the rising section 4012 is runway-shaped, and the maximum dimension of the rising section 4012 along the width direction is d, wherein h, d and r satisfy the relationship: 0.3≤h / (d / 2-r)≤0.6, and the units of h, d and r are all mm. It should be noted that the upper surface of the side portion 221 is inclined to form a slope, and the maximum height of the side portion 221 refers to the height of the side portion 221 at the position farthest from the middle portion 222 along the length direction, that is, the dimension along the up and down directions at the circumferential edge of the second column segment 220, that is, h is the slope height of the slope formed on the upper side of the side portion 221; the opening profile of the rising section 4012 is runway-shaped, and the maximum dimension d of the rising section 4012 along the width direction refers to the distance between the two straight segments of the runway, which is also equal to the diameter of the semicircular arc segments on both sides of the runway; the cross-sectional area of ​​the runway-shaped pole is large and the flow area is large, which is suitable for the use of batteries with smaller cover widths such as blade batteries; the dividing line between the side portion 221 and the middle portion 222 is as shown Figure 3 The dotted lines in the figure are only for reference. In fact, the pole is formed as a whole. Figure 4 and Figure 7 The “width direction” indicated by the arrow in the middle is perpendicular to the length direction.

[0053] Further integration Figure 2 、 Figure 3 、 Figure 7 and Figure 9As shown, d / 2-r is the single-side expansion width reserved between the expansion section 4012 of the rivet hole 401 and the second column section 220. If h / (d / 2-r) is less than 0.3, the side 221 of the arc segment will not expand enough, and the interval between the riveted pole and the riveted block 4 will be too large, affecting the welding of the pole and the riveted block 4; if h / (d / 2-r) is greater than 0.6, the expansion compensation height h at the top of the side 221 will be too large, the expansion space provided by the riveted block 4 will be insufficient, the contact surface between the pole and the riveted block 4 will be insufficient, and welding will be impossible, the resistance value between the pole and the riveted block 4 will increase, and the welding surface between the top of the pole and the riveted block 4 will be uneven, the risk of welding explosion points and other defects will increase, which will also lead to an increase in resistance value.

[0054] Therefore, by limiting the relationship between h, d and r to 0.3≤h / (d / 2-r)≤0.6, it is possible to avoid the phenomenon of insufficient material expansion in the side portion 221 after the pole is riveted, and to avoid the phenomenon of insufficient material expansion space reserved for the rivet hole 401 due to the excessive expansion compensation height of the side portion 221, thereby ensuring smooth welding between the pole and the riveted block 4 after riveting, and ensuring the welding quality, avoiding excessive resistance between the pole and the riveted block 4, thereby ensuring the charging and discharging performance of the battery cell.

[0055] In one embodiment, the relationship between d and r is: 0.3mm≤d / 2-r≤1.5mm. It should be noted that d / 2-r is the single-sided expansion width reserved between the expansion section 4012 of the rivet hole 401 and the second column section 220. If d / 2-r is less than 0.3mm, the connection strength between the pole and the riveted block 4 is insufficient after riveting and it is easy to fall off; if d / 2-r is greater than 1.5mm, it is easy to cause the problem of insufficient expansion of the pole. Therefore, by limiting the value of d / 2-r to 0.3mm to 1.5mm, it can be ensured that there is sufficient connection strength between the pole and the riveted block 4 after riveting, avoiding the pole and the riveted block 4 from being separated, thereby ensuring the reliability of the cover assembly, and avoiding the phenomenon of insufficient expansion of the pole due to the reserved expansion space being too large, thereby further ensuring that the internal resistance between the pole and the riveted block 4 is within a reasonable range, thereby ensuring the charge and discharge performance of the battery cell.

[0056] In one embodiment, the difference h between the maximum height of the side portion 221 and the height of the middle portion 222 has a value range of: 0.05mm≤h≤0.8mm. If h is less than 0.05mm, the additional height of the expanded material added to the top of the side portion 221 is too small, making processing difficult; if h is greater than 0.8mm, the compensation height is too large, affecting the welding between the pole and the riveted block 4 after riveting. Therefore, by limiting h to a value within the range of 0.05mm to 0.8mm, it is possible to reduce the difficulty of processing and ensure the smooth processing and forming of the pole, and reduce the difficulty of welding between the pole and the riveted block 4 after riveting, ensuring welding quality, and further avoiding excessive resistance between the pole and the riveted block 4.

[0057] In one embodiment, the maximum dimension d of the expansion section 4012 along the width direction is in the range of 4mm≤d≤20mm. If d is less than 4mm, the expansion space provided by the expansion section 4012 is too small, and the second column section 220 of the pole will squeeze the rivet block after expansion, causing the rivet block to deform and the width of the rivet block 4 to be out of tolerance. If d is greater than 20mm, the expansion area provided by the expansion section 4012 is too large, and the pole cannot fill the expansion space, resulting in abnormalities such as poor resistance. Therefore, by limiting the value of d to a range of 4mm to 20mm, it is ensured that the expansion section 4012 of the rivet hole 401 can provide a reasonable expansion space. This can not only prevent the pole from excessively squeezing the rivet block 4 after riveting, causing serious deformation and dimensional deviation of the rivet block 4, but also ensure that the pole can fill the gap between the second column section 220 and the expansion section 4012 after riveting, thereby avoiding abnormal resistance between the pole and the rivet block 4.

[0058] In one embodiment, the radius r of the semicircle formed by the orthographic projection of the side portion 221 on the plate body 1 has a value range of: 1.5mm≤r≤10mm. It should be noted that the dimension of the middle portion 222 along the width direction is equal to 2r, that is, the maximum dimension of the second column segment 220 along the width direction is 2r. If r is less than 1.5mm, the size of the second column segment 220 of the pole is too small, and it is difficult to form a riveted structure; if r is greater than 10mm, the size of the second column segment 220 is too large, requiring a larger riveting pressure, and it is difficult to accurately control the size of the material expansion during the riveting process, affecting the connection between the pole and the riveting block 4. Therefore, by limiting r to a value within the range of 1.5mm to 10mm, it is ensured that the second column segment 220 has a reasonable size, which can not only ensure that the pole can smoothly form a riveted structure after riveting, but also ensure the connection strength between the pole and the riveting block 4 after riveting, thereby ensuring the reliability of the cover assembly.

[0059] It should be noted that the above-mentioned structures and related parameters of the poles are all structures and parameters before riveting.

[0060] The following examples illustrate the effects of different values ​​of h / (d / 2-r) on the resistance R between the pole and the rivet block. The measurement results of the embodiment and the comparative example are shown in Tables 1 to 3. The cover plate assembly of the embodiment satisfies the relationship of 0.3≤h / (d / 2-r)≤0.6; the cover plate assembly of the comparative example does not satisfy the relationship of 0.3≤h / (d / 2-r)≤0.6.

[0061] Case 1: d and r take certain values, d = 4.3mm, r = 1.8mm. By taking different values ​​of h, verify whether the resistance value R between the terminal and the rivet block meets the requirement (requirement: R ≤ 0.035mΩ) under different values ​​of h / (d / 2-r). The test results are shown in Table 1.

[0062] Table 1

[0063] h(mm) d(mm) r(mm) h / (d / 2-r) R(mΩ) Example 1-1 0.105 4.3 1.8 0.30 0.035 Example 1-2 0.12 4.3 1.8 0.34 0.031 Examples 1-3 0.15 4.3 1.8 0.43 0.0284 Examples 1-4 0.17 4.3 1.8 0.49 0.0243 Examples 1-5 0.185 4.3 1.8 0.53 0.0312 Examples 1-6 0.21 4.3 1.8 0.60 0.035 Comparative Example 1-1 0.06 4.3 1.8 0.17 0.0421 Comparative Example 1-2 0.09 4.3 1.8 0.26 0.0371 Comparative Examples 1-3 0.23 4.3 1.8 0.66 0.0367 Comparative Examples 1-4 0.243 4.3 1.8 0.69 0.0419

[0064] Case 2: d and r take certain values, d = 4.8 mm, r = 2 mm. By taking different values ​​of h, verify whether the resistance value R between the terminal and the rivet block meets the requirement (requirement: R ≤ 0.035 mΩ) under different values ​​of h / (d / 2-r). The test results are shown in Table 2.

[0065] Table 2

[0066] h(mm) d(mm) r(mm) h / (d / 2-r) R(mΩ) Example 2-1 0.12 4.8 2 0.30 0.035 Example 2-2 0.135 4.8 2 0.34 0.0316 Example 2-3 0.16 4.8 2 0.40 0.0281 Examples 2-4 0.19 4.8 2 0.48 0.0253 Examples 2-5 0.215 4.8 2 0.54 0.0322 Examples 2-6 0.24 4.8 2 0.60 0.035 Comparative Example 2-1 0.07 4.8 2 0.18 0.0431 Comparative Example 2-2 0.09 4.8 2 0.23 0.0381 Comparative Examples 2-3 0.262 4.8 2 0.66 0.0387 Comparative Examples 2-4 0.279 4.8 2 0.70 0.0429

[0067] Case 3: d and r take certain values, d = 6 mm, r = 2.5 mm. By taking different values ​​of h, verify whether the resistance value R between the terminal and the rivet block meets the requirement (requirement: R ≤ 0.035 mΩ) under different values ​​of h / (d / 2-r). The test results are shown in Table 3.

[0068] Table 3

[0069]

[0070]

[0071] 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, h / (d / 2-r) is within the range of 0.3 to 0.6 as defined in this application. In the riveted cover assembly, the resistance R between the pole and the riveted block is less than or equal to 0.035 mΩ, which meets the requirements; while in Comparative Examples 1-1 to 1-2, Comparative Examples 2-1 to 2-6, and Comparative Examples 3-1 to 3-6, h / (d / 2-r) is within the range of 0.3 to 0.6 as defined in this application. 2. In Comparative Examples 3-1 to 3-2, h / (d / 2-r) is less than 0.3, which is not within the range defined in this application. In Comparative Examples 1-3 to 1-4, Comparative Examples 2-3 to 2-4, and Comparative Examples 3-3 to 3-4, h / (d / 2-r) is greater than 0.6, which is not within the range defined in this application. The resistance value R of the comparative examples is greater than 0.035 mΩ, and the resistance between the pole and the riveted block is too large, which does not meet the requirements.

[0072] In summary, when h / (d / 2-r) is in the range of 0.3 to 0.6, the resistance value R between the riveted pole and the riveted block can meet the requirements, and the performance of the cover assembly meets the requirements and has good performance.

[0073] In one embodiment, the orthographic projection of the first column segment 210 on the plate body 1 is runway-shaped, and the circumferential dimension of the first column segment 210 is greater than the circumferential dimension of the second column segment 220. The first column segment 210 is adapted to be inserted into the pole hole 301 on the cover body 3. By providing a runway-shaped orthographic projection of both the first column segment 210 and the second column segment 220 on the plate body 1 in the vertical direction, the processing and forming of the column 2 is facilitated, and a larger flow area for the pole is ensured. Furthermore, by providing a circumferential dimension of the first column segment 210 greater than that of the second column segment 220, smooth assembly of the pole with the cover body 3 and the rivet block 4 is ensured.

[0074] It should be noted that the center line of the first column segment 210 coincides with the center line of the second column segment 220, and the upper surface of the portion of the first column segment 210 that is larger than the second column segment 220 along the circumferential direction forms an annular supporting surface, which is suitable for supporting the lower surface of the riveting block 4.

[0075] In addition, in other embodiments, the orthographic projections of the second column segment 220 and the first column segment 210 on the plate 1 may also be rectangles.

[0076] The pole of this embodiment is optimized based on the existing runway-type pole. A slope is added to the semicircular arc portion of the second pole section 220 where the pole and the rivet block 4 cooperate, thereby increasing the semicircular arc expansion. Compared with the traditional runway-type pole, the problem of increased resistance between the pole and the rivet block 4 caused by uneven riveting pressure and expansion of the pole and welding abnormalities is improved.

[0077] According to an embodiment of the present invention, on the other hand, a cover plate assembly is provided. Figures 4 to 12 As shown, the cover assembly includes: a cover body 3, a rivet block 4, and the aforementioned pole. The cover body 3 is provided with a pole hole 301; the rivet block 4 is disposed on one side of the cover body 3, and a rivet hole 401 corresponding to the pole hole 301 is disposed on the rivet block 4. The plate body 1 of the pole is located on the side of the cover body 3 facing away from the rivet block 4, with the first pole segment 210 passing through the pole hole 301 and the second pole segment 220 passing through the rivet hole 401. By disposing 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 disposing the pole structure's column 2 sequentially passing 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, the cover body 3, and the rivet block 4 is facilitated.

[0078] In one embodiment, the rivet hole 401 includes a positioning section 4011 and an expanding section 4012. The expanding section 4012 is connected to the end of the positioning section 4011 facing away from the cover plate body 3. The opening profiles of the positioning section 4011 and the expanding section 4012 are both runway-shaped, and the opening size of the expanding section 4012 is larger than the opening size of the positioning section 4011. The opening size refers to the circumferential size of the through hole.

[0079] Further integration Figure 7 As shown, before riveting, there is a gap between the second column segment 220 and the positioning segment 4011 and the expanding segment 4012, and the gap between the second column segment 220 and the expanding segment 4012 is larger; after riveting, the second column segment 220 expands in a direction away from the center line of the column 2, thereby filling the gap between the second column segment 220 and the rivet hole 401, and the outer peripheral size of the column segment corresponding to the expanding segment 4012 on the second column segment 220 is larger than the outer peripheral size of the column segment corresponding to the positioning segment 4011, thereby limiting the downward movement of the column 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 realizing relative fixation between the pole structure, the riveting block 4 and the cover body 3. Therefore, by setting the opening size of the expanding section 4012 of the rivet hole 401 to be larger than the opening size of the positioning section 4011, 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.

[0080] In one embodiment, the rivet hole 401 further includes a sinking section 4013, which is connected to the end of the rising section 4012 away from the positioning section 4011. The sinking section 4013 has the same shape as the rising section 4012, which is a runway shape, and the opening size of the sinking section 4013 is larger than the opening size of the rising section 4012. It should be noted that after the pole structure is riveted, the upper surface of the pole sinks after riveting, and the pole needs to be welded to the rivet block 4 along the outer periphery of the upper surface of the second pole section 220 to reduce the internal resistance between the pole structure and the rivet block 4. The welding position is as follows: Figure 11 As shown by the arrow "P", since the weld has a certain height, by setting a sinking section 4013 on the upper part of the rivet hole 401, and setting the opening contour of the sinking section 4013 to be larger than the opening contour of the rising section 4012, it can be ensured that the weld does not exceed the surface of the rivet block 4, thereby ensuring the smooth welding of the subsequent bus on the cover assembly.

[0081] In one embodiment, further combined Figures 6 and 7As shown, after the cover plate assembly is assembled before riveting, the highest point of the pole (i.e., the position of the side portion 221 farthest from the center line of the column 2 along the length direction) is higher than the upper end surface of the rising section 4012 and is located within the range of the sinking section 4013. In addition, in other embodiments, the highest point of the pole can also be flush with the upper end surface of the rising section 4012, or lower than the upper end surface of the rising section 4012. The upper end surface refers to the position along the Figures 6 and 7 The end face in the direction of "up" pointed by the middle arrow; the highest point refers to the point farthest from the plate body 1 in the up and down directions.

[0082] Preferably, if Figure 11 As shown, the upper end surface of the riveted pole is flush with the upper end surface of the rising section 4012, which facilitates welding of the pole and the riveted block 4. It is understandable that the upper end surface of the riveted pole and the upper end surface of the rising section 4012 can also have a small height difference without affecting the welding of the pole and the riveted block.

[0083] The cover assembly assembled with the pole before improvement is as follows Figures 15 to 17 As shown, the upper surface of the pole is flat, which easily leads to insufficient expansion of the side portion 221 and uneven expansion of the pole along the circumference, affecting the welding between the pole and the riveted block 4 and causing abnormal internal resistance between the pole and the riveted block 4 .

[0084] In one embodiment, the cover assembly further includes a sealing ring 5, which is sleeved on the outer peripheral side of the first column segment 210 and located between the first column segment 210 and the pole hole 301. The sealing ring 5 can ensure the sealing and insulation between the pole and the cover body 3.

[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 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.

[0088] 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.

[0089] 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, characterized in that: include: plate body; The column includes a first column segment and a second column segment, the first column segment is fixedly connected between the plate body and the second column segment, the second column segment is suitable for passing through the rivet hole on the rivet block, the second column segment includes two side portions arranged opposite to each other along the length direction, and a middle portion connected between the two side portions, the side portions are flush with the lower surface of the middle portion, and the upper surface of the side portions protrudes upward from the plane where the upper surface of the middle portion is located.

2. The pole according to claim 1, characterized in that The upper surface of the side portion is inclined along the length direction, and along the length direction, the height of the side portion close to the middle portion is lower than the height of the side portion away from the middle portion.

3. The pole according to claim 2, characterized in that The orthographic projection of the second column section on the plate body is runway-shaped, the orthographic projection of the side portion on the plate body is semicircular, and the radius of the semicircle is r, the difference between the maximum height of the side portion and the height of the middle portion is h, the rivet hole includes a rising section, and the opening profile of the rising section is runway-shaped, and the maximum dimension of the rising section along the width direction is d, wherein the relationship between h, d and r satisfies the following formula: 0.3≤h / (d / 2-r)≤0.

6.

4. The pole according to claim 3, characterized in that The relationship between d and r is: 0.3mm≤d / 2-r≤1.5mm.

5. The pole according to claim 3, characterized in that: The difference h between the maximum height of the side portion and the height of the middle portion has a value range of: 0.05 mm ≤ h ≤ 0.8 mm.

6. The pole according to claim 3, characterized in that The maximum dimension d of the expanding section along the width direction is in the range of 4 mm ≤ d ≤ 20 mm; And / or, the radius r of the semicircle formed by the orthographic projection of the side portion on the plate body has a value range of: 1.5 mm ≤ r ≤ 10 mm.

7. The pole according to any one of claims 1 to 6, characterized in that The orthographic projection of the first column segment on the plate body is in a runway shape, and the circumferential dimension of the first column segment is greater than the circumferential dimension of the second column segment.

8. 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 according to any one of claims 1 to 7, wherein the plate body of the pole is located on a side of the cover body facing away from the rivet block, the first pole segment is inserted into the pole hole, and the second pole segment is inserted into the rivet hole.

9. The cover plate assembly according to claim 8, wherein: The riveting hole includes a positioning section and a material expansion section, the material expansion section is connected to the end of the positioning section away from the cover body, the opening contours of the positioning section and the material expansion section are both runway-shaped, and the opening size of the material expansion section is larger than the opening size of the positioning section.

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

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