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 is connected to the upper side of the plate body, the column body comprises a first column part and a second column part, the first column part is fixedly connected between the plate body and the second column part, the first column part is suitable for being arranged in a pole hole in the cover plate body in a penetrating mode, and the outer contour of the upper surface of the first column part is the same as the outer contour of the bottom surface in shape; the cross sectional area of the first column part is gradually reduced from bottom to top; the maximum size of the upper surface of the first column part in the length direction is d, the maximum size of the bottom surface of the first column part in the length direction is D, the height of the first column part in the vertical direction is h, and # imgabs0 can ensure that enough material expansion space is reserved for the first column part, so that the width consistency of the cover plate body is ensured; and insufficient filling of the first column part caused by the fact that the reserved material expansion space is too large can be avoided, so that the over-current capability of the pole column is ensured.

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, rivet block, upper and lower plastic components, and a sealing ring. The pole has a first portion that fits within the pole hole in the cover body and a second portion that fits within 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 the second portion to expand and deform within the rivet hole until it fits within the hole, thereby riveting the pole to the cover body via the rivet block.

[0003] However, due to the influence of the rivet pin pressure, the column section on the first column part close to the rivet block will also be compressed and expanded and thickened, and the existing technology usually does not take into account the expansion and deformation of this part, resulting in the first column part over-squeezing the cover plate body. In severe cases, the cover plate body will be stretched open in the width direction, causing the cover plate body to expand and deform, the width to exceed the tolerance, and the width consistency of the cover plate body to be poor, which in turn leads to problems such as difficulty in assembling the shell cover, affecting the safety of the battery cell. Summary of the Invention

[0004] In view of this, the present invention provides a pole, a cover plate assembly and a battery cell to solve the problem of poor width consistency of the cover plate body caused by excessive compression of the pole by the cover plate body.

[0005] In a first aspect, the present invention provides a pole, comprising: a plate body; a column connected to the upper side of the plate body, the column comprising a first column portion and a second column portion, the first column portion being fixedly connected between the plate body and the second column portion, the first column portion being adapted to be inserted into a pole hole on a cover plate body, the outer contour of the upper surface of the first column portion being the same as the outer contour of the bottom surface, and the cross-sectional area of ​​the first column portion gradually decreasing from bottom to top; the maximum dimension of the upper surface of the first column portion along the length direction is d, the maximum dimension of the bottom surface of the first column portion along the length direction is D, and the height of the first column portion along the vertical direction is h, wherein,

[0006] Beneficial effect: By setting the outer contour shape of the upper surface and the bottom surface of the first column portion to be the same, and the cross-sectional area of ​​the first column portion gradually decreases from bottom to top, the first column portion is made into a truncated cone or a quasi-truncated cone structure, thereby gradually reducing the circumferential size of the first column portion from bottom to top, and gradually increasing the distance between the first column portion and the pole hole, reserving space for deformation of the first column portion during the riveting process, avoiding excessive squeezing of the cover plate body due to excessive thickening of the part of the first column portion close to the second column portion after riveting, thereby avoiding stretching the cover plate body in the width direction, ensuring the consistency of the width of the cover plate body after riveting, and avoiding problems such as difficulty in assembling the shell cover and poor welding. In addition, by limiting the inclination angle of the outer circumferential surface of the first column portion relative to the plate body to be between 84° and 88°, it can be ensured that sufficient space is reserved for the expansion of the first column portion, thereby ensuring the consistency of the width of the cover plate body, and it can be avoided that the reserved expansion space is too large and the first column portion is insufficiently filled with expansion material, thereby ensuring the overcurrent capacity of the pole.

[0007] In an optional embodiment, D and d satisfy the relationship: 0.1 mm ≤ Dd ≤ 0.8 mm;

[0008] And / or, in an optional embodiment, the height h of the first column portion along the vertical direction is in the range of: 3 mm ≤ h ≤ 6 mm;

[0009] And / or, the maximum dimension D of the bottom surface of the first column portion along the length direction is in the range of: 4.5 mm ≤ D ≤ 30 mm.

[0010] Beneficial Effect: By limiting the difference between the maximum dimension D of the bottom surface of the first column along the length direction and the maximum dimension d of the upper surface of the first column along the length direction to be between 0.1 mm and 0.8 mm, the smooth processing and forming of the pole can be ensured, and insufficient filling of the first column due to excessive space reserved for expansion along the first column can be avoided, thereby ensuring the structural strength and current-carrying capacity of the pole;

[0011] By limiting the height h of the first column portion in the vertical direction to a value within the range of 3 mm to 6 mm, it is possible to ensure that the pole has sufficient structural strength, ensure the connection strength and sealing of the cover assembly after riveting, and ensure smooth assembly and riveting of the cover assembly;

[0012] By limiting the value of D to the range of 4.5 mm to 30 mm, it is possible to ensure that the pole has sufficient current capacity and can be smoothly processed and formed, while also avoiding excessive weight of the pole, thereby saving costs.

[0013] In an optional embodiment, the outer contour of the bottom surface of the first column portion is a first contour line, the contour line of the positive projection of the upper surface of the first column portion on the plate body is a second contour line, and the second contour line has the same shape as the first contour line and is concentrically arranged.

[0014] Beneficial effect: By setting the first contour line and the second contour line concentrically, the symmetry of the first column portion is ensured, which is convenient for processing and forming, and can ensure the symmetry of the expansion space reserved on both sides of the first column portion along the width direction, ensuring that after the first column portion expands, both sides along the width direction will not excessively squeeze the cover body, thereby further ensuring that the side edges of the cover body along both sides of the width will not expand and deform outward, ensuring the consistency of the width of the cover body.

[0015] In an optional embodiment, the positive projection of the second column portion on the plate body is a third contour line, the third contour line has the same shape as the second contour line, and the area enclosed by the third contour line is smaller than the area enclosed by the second contour line, and the third contour line is concentrically arranged with the first contour line and the second contour line.

[0016] Beneficial effect: By setting the third contour line concentrically with the first contour line and the second contour line, the center line of the second column portion coincides with the center line of the first column portion, which facilitates the processing and forming of the column, and the circumferential dimension of the second column portion is smaller than the circumferential dimension of the first column portion, which can ensure the smooth assembly of the pole, the cover plate body and the rivet block.

[0017] In an optional embodiment, a first ring is formed between the first contour line and the third contour line, and the width of the first ring is W, wherein W satisfies the relationship between D and d:

[0018]

[0019] Beneficial effect: It can ensure that there is enough space for the first column to expand, thereby ensuring the consistency of the width of the cover body, and can also avoid the reserved expansion space being too large, which will cause insufficient filling of the first column, thereby ensuring that the rivet block and the upper surface of the first column have sufficient contact area after riveting, avoiding excessive resistance and ensuring the overcurrent capacity of the battery cell.

[0020] In an optional embodiment, the value range of the ring width W of the first ring is: 0.3mm≤W≤1mm.

[0021] Beneficial effects: It can ensure that the pole is smoothly processed and formed, and the first column portion has sufficient support area for the rivet block, avoiding riveting pressure and damaging the fitting surface between the rivet block and the first column portion, and can ensure that the pole and the rivet block have sufficient connection strength after riveting, thereby improving the reliability of the battery cell.

[0022] In an optional embodiment, the first contour line, the second contour line, and the third contour line are all runway-shaped;

[0023] Alternatively, the first contour line, the second contour line, and the third contour line are all circular.

[0024] Beneficial effect: By setting the contour line of the orthographic projection of the upper surface of the first column portion on the plate body, the outer contour of the bottom surface of the first column portion, and the orthographic projection of the second column portion on the plate body to be runway-shaped, the first column portion is optimized on the basis of the runway-shaped pole, and the second column portion is a runway-shaped columnar structure. The cross-sectional area of ​​the pole is larger and the current-carrying capacity of the pole is better.

[0025] By setting the contour line of the positive projection of the upper surface of the first column on the plate body, the outer contour of the bottom surface of the first column and the positive projection of the second column on the plate body to be circular, the first column is optimized based on the cylindrical pole, and the second column is cylindrical, with a simple structure and easy processing and forming.

[0026] In an optional embodiment, the first contour line is runway-shaped, and the maximum dimension of the first contour line along the width direction is A, wherein 4 mm ≤ A ≤ 20 mm.

[0027] Beneficial effect: By limiting the value of A to the range of 4 mm to 20 mm, the difficulty of pole processing and riveting can be reduced.

[0028] In a second aspect, the present invention further provides a cover plate assembly comprising: a cover plate body having a pole hole defined therein; a rivet block disposed on one side of the cover plate body, the rivet block having a rivet hole corresponding to the pole hole defined therein; a pole plate located on a side of the cover plate body facing away from the rivet block, a first pole portion extending through the pole hole, and a second pole portion extending through the rivet hole; and a sealing ring disposed between the first pole portion and the pole hole. Because the cover plate assembly includes the pole, it has the same function as the pole and is not further described here.

[0029] 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

[0030] 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.

[0031] Figure 1 This is a front view of a pole before riveting according to an embodiment of the present invention;

[0032] Figure 2 for Figure 1 A top view of the pole shown;

[0033] Figure 3 for Figure 2 A partial enlarged schematic diagram of the area including the column;

[0034] Figure 4 for Figure 2 Cross-sectional view in the middle BB direction;

[0035] Figure 5 A top view of a cover plate assembly before riveting according to an embodiment of the present invention;

[0036] Figure 6 for Figure 5 Cross-sectional view in CC direction;

[0037] Figure 7 for Figure 5 Cross-sectional view in the EE direction;

[0038] Figure 8 A top view of a riveted cover plate assembly according to an embodiment of the present invention;

[0039] Figure 9 for Figure 8 Cross-sectional view in the FF direction;

[0040] Figure 10 for Figure 8 An exploded view of the cover assembly after riveting is shown;

[0041] Figure 11 It is a front view of a traditional pole;

[0042] Figure 12 This is a CT image of the cover assembly after traditional riveting.

[0043] Description of reference numerals:

[0044] 1. Plate body; 2. Column; 201. First contour line; 202. Second contour line; 203. Third contour line; 204. First ring; 210. First column portion; 220. Second column portion; 3. Cover body; 301. Pole hole; 302. Explosion-proof valve hole; 4. Riveted block; 401. Riveted hole; 4011. First hole section; 4012. Second hole section; 4013. Third hole section; 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

[0045] 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.

[0046] As lithium-ion battery technology matures, it is widely used as a power battery in electric vehicles and energy storage, leading to increasingly stringent performance and safety requirements. Lithium-ion battery covers are key components in lithium-ion cells. They weld to the casing to form a sealed cavity, connect the positive and negative electrodes to the electrode assembly, and serve as an assembly support. Traditionally, the cover assembly consists of a riveting block, upper plastic, terminal, cover body, lower plastic, and sealing ring. In line with the trend toward lightweight components and simplified structures, blade covers have been simplified from dual cylindrical terminals to single terminals. The terminal body adopts a runway-shaped structure, and the cover body is smaller in width. During terminal riveting, the downward pressure from the rivet pin causes the terminal to expand and thicken, squeezing the sealing ring. In severe cases, this can push the top cover apart, causing width deviations or short-circuiting between the terminal and cover, threatening battery cell safety.

[0047] The following combination Figures 1 to 12 , describing embodiments of the present invention.

[0048] According to an embodiment of the present invention, on the one hand, a pole is provided, such as Figures 1 to 4As shown, the pole includes: a plate body 1 and a column 2. The column 2 is connected to the upper side of the plate body 1, and the column 2 includes a first column portion 210 and a second column portion 220. The first column portion 210 is fixedly connected between the plate body 1 and the second column portion 220. The first column portion 210 is suitable for passing through the pole hole 301 on the cover body 3. The outer contour of the upper surface of the first column portion 210 is the same as the outer contour of the bottom surface, and the cross-sectional area of ​​the first column portion 210 gradually decreases from bottom to top; the maximum dimension of the upper surface of the first column portion 210 along the length direction is d, the maximum dimension of the bottom surface of the first column portion 210 along the length direction is D, and the height of the first column portion 210 along the vertical direction is h, wherein, The up and down directions refer to Figure 1 and Figure 4 The direction of "up and down" indicated by the middle arrow is parallel to the direction of the center line of the column 2; from bottom to top refers to the direction from the plate 1 to the second column 220 along the center line of the column 2; the bottom surface of the first column 210 refers to the lower end surface of the first column 210, that is, the end surface of the first column 210 connected to the plate 1; when the pole is used in the battery cell, the upper side of the plate 1 is the side of the plate 1 facing the cover body 3; the length direction refers to Figures 1 to 3 The arrow in the middle points to the "length direction".

[0049] It should be noted that the shape and size of the pole in this embodiment are the characteristics of the pole before riveting. The cross-sectional area refers to the orthographic projection area on the cross section perpendicular to the center line of the column 2. Since the cross-sectional area of ​​the first column 210 gradually decreases from bottom to top, the first column 210 is a truncated cone or a quasi-truncated cone structure. The outer peripheral surface of the first column 210 is inclined relative to the upper surface of the plate 1. The first column 210 is symmetrically arranged about its center line. Figure 1 As shown, the outer peripheral surface of the first column portion 210 has an inclination angle θ relative to the plate body 1. If θ is less than 84°, the angle between the outer circumference of the first column 210 and the plate body 1 is too small, and the portion of the first column 210 close to the second column 220 is too much retracted inward relative to the bottom outer contour of the second column 220. The riveting deformation space reserved for the first column 210 is too large. After riveting, the portion of the first column 210 close to the second column 220 is insufficiently filled with material, and the cross-sectional area is too small, which affects the overcurrent capacity. Among them, retracting inward refers to the portion close to the center of the first column 210. If θ is greater than 88°, the angle between the outer peripheral surface of the first column portion 210 and the plate body 1 is too large, and the size of the portion of the first column portion 210 close to the second column portion 220 that is retracted inward relative to the bottom outer contour of the second column portion 220 is too small, and the riveting deformation space reserved for the first column portion 210 is too small. After riveting, the portion of the first column portion 210 close to the second column portion 220 expands and excessively squeezes the inner wall of the pole hole 301, stretching the pole hole 301, causing the width of the cover plate body 3 to be out of tolerance.

[0050] Among them, the outer peripheral surface of the first column portion 210 refers to the circumferential curved surface connected between the outer contour of the upper surface of the first column portion 210 and the outer contour of the bottom surface; the cross-sectional area of ​​the first column portion 210 decreases uniformly from bottom to top, and the outer peripheral surface of the first column portion 210 transitions smoothly. The intersection line of any cross-section passing through the center line of the first column portion 210 and perpendicular to the upper surface of the plate body 1 and the outer peripheral surface of the first column portion 210 forms a first line segment. The first line segment is a straight line segment, and the angle between the first line segment and the plate body 1 is the inclination angle θ of the outer peripheral surface of the first column portion 210 relative to the plate body 1.

[0051] The pole of the present embodiment is applied, by setting the outer contour shape of the upper surface and the bottom surface of the first column 210 to be the same, and the cross-sectional area of ​​the first column 210 gradually decreases from bottom to top, so that the first column 210 is in a truncated cone or truncated cone structure, thereby gradually reducing the circumferential size of the first column 210 from bottom to top, and gradually increasing the distance between the first column 210 and the pole hole 301, so as to reserve a space for deformation of the material during the riveting process of the first column 210, thereby avoiding excessive squeezing due to the part of the first column 210 close to the second column 220 becoming too thick after riveting. The cover plate body 3 is pressed, thereby avoiding stretching the cover plate body 3 along the width direction, ensuring the consistency of the width of the cover plate body 3 after riveting, and avoiding problems such as difficulty in shell cover assembly and poor welding. In addition, by limiting the inclination angle of the outer peripheral surface of the first column portion 210 relative to the plate body 1 to be between 84° and 88°, it can be ensured that sufficient expansion space is reserved for the expansion of the first column portion 210, thereby ensuring the consistency of the width of the cover plate body 3, and it can also avoid the reserved expansion space being too large, which causes insufficient filling of the first column portion 210, thereby ensuring the overcurrent capacity of the pole.

[0052] The width direction refers to Figures 2 to 4 and Figure 5 、 Figure 8 The arrow in the middle points to the "width direction".

[0053] Further integration Figure 11 As shown, the first column portion 210 of the conventional pole is columnar, and its cross-sectional area at different positions along the vertical direction is equal; it should be noted that during riveting, the riveting effect of the rivet on the first column portion 210 gradually weakens from top to bottom. Therefore, the riveting effect on the portion of the first column portion 210 close to the second column portion 220 is more obvious, and the expansion deformation of this portion is more obvious than that of the portion of the second column portion 220 close to its bottom. Figure 12 As shown, from the CT diagram of the traditional cover plate assembly along the width direction after riveting, it can be seen that the part of the first column 210 close to the second column 220 (i.e., the part indicated by the rectangular frame in the figure) has a more serious material expansion. This part is most likely to stretch the cover plate body 3 along the width direction, causing the width of the cover plate body 3 to be out of tolerance, making it difficult to assemble the shell cover, or excessively squeeze the sealing ring 5, causing the sealing ring 5 to be damaged, thereby causing the pole and the cover plate body 3 to contact and short-circuit, seriously threatening the safety of the battery cell. The outer peripheral surface of the first column 210 of the pole of this embodiment is tilted relative to the plate body 1. The structural form can reserve material expansion space for the first column 210, and the material expansion space reserved between the first column 210 and the inner wall of the pole hole 301 gradually increases from bottom to top, which is in line with the material expansion law of the first column 210 and can effectively overcome the above-mentioned problems.

[0054] In one embodiment, further combined Figure 3 As shown, the outer contour of the bottom surface of the first column portion 210 is the first contour line 201, and the contour line of the positive projection of the upper surface of the first column portion 210 on the plate body 1 is the second contour line 202. The second contour line 202 has the same shape as the first contour line 201 and is concentrically arranged. Among them, the area enclosed by the first contour line 201 is larger than the area enclosed by the second contour line 202, that is, the bottom surface of the first column portion 210 is larger than the upper surface. By concentrically arranging the first contour line 201 and the second contour line 202, the symmetry of the first column portion 210 is ensured, which is convenient for processing and forming, and can ensure the symmetry of the expansion space reserved on both sides of the width direction of the first column portion 210, ensuring that the first column portion 210 will not over-extrude the cover plate body 3 on both sides along the width direction after expansion, thereby further ensuring that the side edges of the cover plate body 3 on both sides along the width will not expand and deform outward, ensuring the consistency of the width of the cover plate body 3.

[0055] In one embodiment, the orthographic projection of the second column portion 220 on the plate body 1 is a third contour line 203. The third contour line 203 has the same shape as the second contour line 202, and the area enclosed by the third contour line 203 is smaller than the area enclosed by the second contour line 202. The third contour line 203 is concentric with the first contour line 201 and the second contour line 202. By arranging the third contour line 203 concentrically with the first contour line 201 and the second contour line 202, the centerline of the second column portion 220 coincides with the centerline of the first column portion 210, facilitating the processing and forming of the column body 2. The circumferential dimension of the second column portion 220 is smaller than the circumferential dimension of the first column portion 210, ensuring smooth assembly of the pole, the cover plate body 3, and the rivet block 4.

[0056] In one embodiment, the first contour line 201, the second contour line 202, and the third contour line 203 are all runway-shaped. By setting the contour line of the orthographic projection of the upper surface of the first column portion 210 on the plate body 1, the outer contour of the bottom surface of the first column portion 210, and the orthographic projection of the second column portion 220 on the plate body 1 to be runway-shaped, the first column portion 210 is optimized based on the racetrack-shaped pole, and the second column portion 220 has a racetrack-shaped columnar structure, the pole has a larger cross-sectional area, and the pole has better current carrying capacity.

[0057] It should be noted that the first contour line 201 and the second contour line 202 are both runway-shaped, that is, the cross-section of the first column portion 210 is runway-shaped, and the first column portion 210 is obtained by improving the traditional columnar structure. At this time, D and d are respectively the maximum dimensions of the runway-shaped first contour line 201 and the second contour line 202 along the length direction, that is, the long axis of the corresponding runway-shaped contour line; along the circumference of the first column portion 210, the inclination angle of any position of the outer circumference of the first column portion 210 relative to the plate body 1 is equal, the maximum dimension of the upper surface of the first column portion 210 along the width direction is a, and the maximum dimension of the bottom surface of the first column portion 210 along the width direction is A, then The same holds true, that is, the relationship between A, a and h satisfies the following equation: Wherein, A and a are the maximum dimensions of the runway shape of the first contour line 201 and the second contour line 202 along the width direction, that is, the short axis of the corresponding runway shape contour line; the width direction refers to Figure 4 The “width direction” indicated by the arrow in the middle is perpendicular to the length direction.

[0058] In addition, in other embodiments, the first contour line 201, the second contour line 202, and the third contour line 203 are all circular. By setting the contour line of the orthographic projection of the upper surface of the first column portion 210 on the plate body 1, the outer contour of the bottom surface of the first column portion 210, and the orthographic projection of the second column portion 220 on the plate body 1 to be circular, the first column portion 210 is optimized based on the cylindrical pole, and the second column portion 220 is cylindrical, which has a simple structure and is easy to process and form.

[0059] It should be noted that the first contour line 201 and the second contour line 202 are both circular. At this time, the cross-section of the first column portion 210 is circular. The first column portion 210 is improved from a traditional cylindrical structure. The maximum dimension d of the upper surface of the first column portion 210 along the length direction is equal to the maximum dimension a of the upper surface of the first column portion 210 along the width direction, and both are the diameters of the circle of the second contour line 202; the maximum dimension D of the bottom surface of the first column portion 210 in the length direction is equal to the maximum dimension A of the bottom surface of the first column portion 210 in the width direction, and both are the diameters of the circle of the first contour line 201.

[0060] In one embodiment, D and d satisfy the relationship: 0.1mm≤Dd≤0.8mm. It should be noted that D and d are the size difference between the first contour line 201 and the second contour line 202. A second ring is formed between the first contour line 201 and the second contour line 202, and the ring width of the second ring is equal to (Dd) / 2. If Dd is less than 0.1mm, the size difference between the first contour line 201 and the second contour line 202 is too small, making the pole difficult to process; if Dd is greater than 0.8mm, the size difference between the first contour line 201 and the second contour line 202 is too large, and the expansion space reserved for the first column part 210 is too large. After riveting, the part of the first column part 210 close to the second column part 220 is insufficiently expanded, resulting in a decrease in the strength of the pole, a decrease in reliability, and an impact on the current capacity of the pole. Among them, since the first contour line 201 and the second contour line 202 are concentrically arranged, A and a also satisfy the relationship: 0.1mm≤Aa≤0.8mm.

[0061] Therefore, by limiting the difference between the maximum dimension D of the bottom surface of the first column portion 210 along the length direction and the maximum dimension d of the upper surface of the first column portion 210 along the length direction to between 0.1 mm and 0.8 mm, it is possible to ensure that the pole is smoothly processed and formed, and to avoid the first column portion 210 being insufficiently filled with material due to the reserved expansion space being too large, thereby ensuring the structural strength and current-carrying capacity of the pole.

[0062] In one embodiment, the height h of the first column portion 210 in the vertical direction ranges from 3mm≤h≤6mm. If h is less than 3mm, the height of the first column portion 210 is too small and insufficient in size, which affects the structural strength of the pole, and the effective crimping length is insufficient during riveting, resulting in insufficient connection strength and poor stability. In addition, the extrusion force on the sealing ring 5 is insufficient, resulting in poor sealing. If h is greater than 6mm, the height of the first column portion 210 is too large, making it difficult to assemble the riveting block 4 and the cover body 3, and the riveting is more difficult. Therefore, by limiting the height h of the first column portion 210 in the vertical direction to a value within the range of 3mm to 6mm, it is possible to ensure that the pole has sufficient structural strength, ensure the connection strength and sealing of the cover assembly after riveting, and ensure the smooth assembly and riveting of the cover assembly.

[0063] In one embodiment, the maximum dimension D of the bottom surface of the first column portion 210 along the length direction is within the range of 4.5 mm ≤ D ≤ 30 mm. If D is less than 4.5 mm, the length of the first column portion 210 is too small, resulting in insufficient current flow capacity and difficulty in forming the pole. If D is greater than 30 mm, the length of the first column portion 210 is too large, resulting in excessive pole weight and waste of material. Therefore, by limiting D to a value within the range of 4.5 mm to 30 mm, sufficient current flow capacity and smooth pole forming can be ensured while also preventing excessive pole weight, thereby saving costs.

[0064] In one embodiment, further combined Figure 1 and Figure 3 As shown, a first ring 204 is formed between the first contour line 201 and the third contour line 203. The width of the first ring 204 is W, wherein W satisfies the relationship between D and d: It should be noted that the cross-sectional area of ​​the first column portion 210 is larger than that of the second column portion 220. The portion of the upper surface of the first column portion 210 that is larger than that of the second column portion 220 along the circumferential direction forms a support surface, which abuts against the lower surface of the riveting block 4. W is the dimension of the first column portion 210 that is larger than that of the second column portion 220 on one side in the direction perpendicular to the axis of the column 2, which is also equal to the annular width of the support surface on the columnar first column portion before the improvement. (Dd) / 2 is the dimension of the upper surface of the first column portion 210 that is reduced inward relative to the size before the improvement, reflecting the size of the expansion space reserved by the first column portion 210. If The space reserved for the expansion of the first column 210 is too small, and the portion of the first column 210 close to the second column 220 expands more during riveting, squeezing and stretching the pole hole 301, causing the width of the cover body 3 to exceed the tolerance; if If it is greater than 0.6, the space reserved for the expansion of the first column 210 is too large, and the part of the first column 210 near the second column 220 after riveting does not expand enough. The contact area between the riveting block 4 and the upper surface of the first column 210 is small, and the resistance is excessive, which affects the current capacity of the battery cell.

[0065] Therefore, by defining Taking a value within the range of 0.2 to 0.6 can ensure that the first column 210 has sufficient space for material expansion, thereby ensuring the consistency of the width of the cover body 3, and can also avoid the reserved space for material expansion being too large, which may cause insufficient filling of the first column 210, thereby ensuring that the riveting block 4 and the upper surface of the first column 210 have sufficient contact area after riveting, avoiding excessive resistance and ensuring the overcurrent capacity of the battery cell.

[0066] It can be understood that the first ring 204 is an elliptical ring or a circular ring. Along the circumference of the first ring 204, the ring width is equal at all locations. Then, W, A, and a satisfy the relationship:

[0067] In one embodiment, the ring width W of the first ring 204 is in the range of 0.3 mm ≤ W ≤ 1 mm. If W is less than 0.3 mm, the circumferential dimension difference between the first column 210 and the second column 220 is too small, and the width of the first column 210 for supporting the rivet block 4 is relatively low. After riveting and pressure, the fitting surface between the rivet block 4 and the first column 210 is easily damaged, and the manufacturing difficulty is relatively high. If W is greater than 1 mm, the circumferential dimension difference between the first column 210 and the second column 220 is too large, resulting in the second column 220 being undersized and insufficient in connection strength with the rivet block 4 after riveting. Therefore, by limiting W to a value within the range of 0.3 mm to 1 mm, it is possible to ensure that the terminal is smoothly processed and formed, and the first column 210 has sufficient support area for the rivet block 4, avoiding damage to the fitting surface between the rivet block 4 and the first column 210 due to riveting pressure, and ensuring that the terminal and the rivet block 4 have sufficient connection strength after riveting, thereby improving the reliability of the battery cell.

[0068] In one embodiment, the first contour line 201 is runway-shaped, and the maximum width dimension of the first contour line 201 is A, where 4 mm ≤ A ≤ 20 mm. It should be noted that the maximum width dimension A of the first contour line 201 corresponds to the maximum width dimension of the bottom surface of the first column portion 210. If A is less than 4 mm or greater than 20 mm, the pole processing becomes more difficult, and the pole riveting becomes difficult. Therefore, by limiting A to a value within the range of 4 mm to 20 mm, the difficulty of pole processing and riveting can be reduced.

[0069] The following uses different pole assembly cover components to measure the width M of the cover body 3 after riveting and the resistance value R between the pole and the riveted block 4 to verify When different values ​​are taken, whether the width M of the cover body meets the tolerance requirement of ±0.05mm and the resistance value R between the pole and the riveted block 4 meets the requirement of R≤0.035mΩ, the measurement results of the embodiment and the comparative example are shown in Tables 1 to 3. Among them, the pole structure of the embodiment meets the requirements of the embodiment. The proportional pole structure does not satisfy M is the position on the cover body 3 corresponding to the pole along Figure 8 The arrow in the middle indicates the dimension in the "width direction".

[0070] Test 1: With pole dimensions D = 8.5mm, A = 4.5mm, h = 3.4mm, and W = 0.6mm, different values ​​of d or a were used to verify whether M and R met the requirements. The test results are shown in Table 1. The cover body width M is required to be 15 ± 0.05mm. The table uses different values ​​of d as examples. Note that as d changes, a also changes, ensuring that Dd = Aa. The same applies to other tables and will not be repeated here.

[0071] Table 1

[0072]

[0073]

[0074] Test 2: Pole dimensions D = 9 mm, A = 5 mm, h = 3.5 mm, W = 0.62 mm. D or a takes different values ​​to verify whether M and R meet the requirements. The test results are shown in Table 2. The cover body width M is required to be 16 ± 0.05 mm.

[0075] Table 2

[0076]

[0077] Test 3: Pole dimensions D = 10 mm, A = 5.5 mm, h = 3.6 mm, and W = 0.63 mm. D or a takes different values ​​to verify whether M and R meet the requirements. The test results are shown in Table 3. The cover body width M is required to be 16.5 ± 0.05 mm.

[0078] Table 3

[0079]

[0080]

[0081] It can be seen from Table 1 that in Examples 1-1 to 1-6, θ (i.e. ) are all within the range of 84° to 88° as defined in this application, The values ​​are all within the range of 0.2 to 0.6 specified in this application. The width M of the cover body after riveting is within the range of 15±0.05mm, and the resistance value R is less than or equal to 0.035mΩ. That is, the width of the cover body after riveting and the resistance between the pole and the riveted block meet the requirements. The cover body 3 after riveting does not have a width deviation, the width consistency of the cover body 3 is good, and the resistance between the pole and the riveted block is small, which meets the requirements. In Comparative Examples 1-1 and 1-2, θ (i.e. ) are greater than 88°, are all less than 0.2, which is not within the range specified in this application. Although the resistance values ​​R are all less than 0.035mΩ, the width M of the cover body after riveting is all greater than 15.05mm (i.e. 15+0.05mm), the width of the cover body 3 is out of tolerance, and the width consistency is poor; in Comparative Examples 1-3 to 1-4, θ (i.e. ) are less than 84°, Both are greater than 0.6, which is not within the range specified in this application. Although the width M of the cover body after riveting is within the range of 15±0.05mm, the resistance value R is greater than 0.035mΩ. The resistance between the pole and the riveted block is too large and does not meet the requirements.

[0082] It can be seen from Table 2 that in Examples 2-1 to 2-6, θ (i.e. ) are all within the range of 84° to 88° as defined in this application, The values ​​are all within the range of 0.2 to 0.6 specified in this application. The width M of the cover body after riveting is within the range of 16±0.05mm, and the resistance value R is less than or equal to 0.035mΩ. That is, the width of the cover body after riveting and the resistance between the pole and the riveted block meet the requirements. The cover body 3 after riveting does not have a width deviation, the width consistency of the cover body 3 is good, and the resistance between the pole and the riveted block is small, which meets the requirements. In Comparative Examples 2-1 and 2-2, θ (i.e. ) are greater than 88°, are all less than 0.2, which is not within the range specified in this application. Although the resistance values ​​R are all less than 0.035mΩ, the width M of the cover body after riveting is greater than 16.05mm (i.e. 16+0.05mm), the width of the cover body 3 is out of tolerance, and the width consistency is poor; in Comparative Examples 2-3 to 2-4, θ (i.e. ) are less than 84°, Both are greater than 0.6, which is not within the range specified in this application. Although the width M of the cover body after riveting is within the range of 16±0.05mm, the resistance value R is greater than 0.035mΩ. The resistance between the pole and the riveted block is too large and does not meet the requirements.

[0083] It can be seen from Table 3 that in Examples 3-1 to 3-6, θ (i.e. ) are all within the range of 84° to 88° as defined in this application, The values ​​are all within the range of 0.2 to 0.6 specified in this application. The width M of the cover body after riveting is within the range of 16.5±0.05mm, and the resistance value R is less than or equal to 0.035mΩ. That is, the width of the cover body after riveting and the resistance between the pole and the riveted block meet the requirements. The cover body 3 after riveting does not have a width deviation, the width consistency of the cover body 3 is good, and the resistance between the pole and the riveted block is small, which meets the requirements. In Comparative Examples 3-1 and 3-2, θ (i.e. ) are greater than 88°, are all less than 0.2, which is not within the range specified in this application. Although the resistance values ​​R are all less than 0.035mΩ, the width M of the cover body after riveting is all greater than 16.55mm (i.e. 16.5+0.05mm), the width of the cover body 3 is out of tolerance, and the width consistency is poor; in Comparative Examples 3-3 to 3-4, θ (i.e. ) are less than 84°, Both are greater than 0.6, which is not within the range specified in this application. Although the width M of the cover body after riveting is within the range of 16.5±0.05mm, the resistance value R is greater than 0.035mΩ. The resistance between the pole and the riveted block is too large and does not meet the requirements.

[0084] In summary, when the pole meets and When the cover plate body 3 is riveted, the width of the riveted cover plate body 3 and the resistance value between the pole and the riveted block meet the use requirements of the cover plate assembly, and the performance of the cover plate assembly is good.

[0085] According to an embodiment of the present invention, on the other hand, a cover plate assembly is provided. Figures 5 to 10 As shown, it includes: a cover body 3, a rivet block 4, the above-mentioned pole and a sealing ring 5. The cover body 3 is provided with a pole hole 301; the rivet block 4 is arranged on one side of the cover body 3, and a rivet hole 401 corresponding to the pole hole 301 is opened on the rivet block 4; the plate body 1 of the pole is located on the side of the cover body 3 away from the rivet block 4, the first column part 210 is passed through the pole hole 301, and the second column part 220 is passed through the rivet hole 401; the sealing ring 5 is provided between the first column part 210 and the pole hole 301. It should be noted that the rivet block 4 is provided on the side of the cover body 3 facing the outside of the shell, and Figure 5 The plate body 1 is arranged on the side of the cover body 3 facing the inside of the shell, and Figure 5The side in the “downward” direction indicated by the middle arrow; the pole hole 301 and the rivet hole 401 are both through holes.

[0086] Among them, by arranging a rivet block 4 on one side of the cover body 3 and a plate body 1 of the pole structure on the other side, and arranging the column 2 of the pole structure to pass through the pole hole 301 on the cover body 3 and the rivet hole 401 on the rivet block 4 in sequence, it is convenient to realize the riveting between the pole structure and the cover body 3 and the rivet block 4, and the sealing ring 5 can ensure the sealing and insulation between the pole and the cover body 3. Compared with the traditional cover structure, the structural form in which the outer peripheral surface of the pole is inclined can improve the abnormality of the sealing ring 5 caused by the riveting of the pole, the abnormality of the extrusion of the cover body 3 or the first plastic part 6, and the abnormality of the short circuit between the pole and the cover body 3, thereby improving the production yield of the cover assembly.

[0087] In one embodiment, the rivet hole 401 includes a first hole segment 4011, a second hole segment 4012, and a third hole segment 4013 connected sequentially from bottom to top. The first hole segment 4011, the second hole segment 4012, and the third hole segment 4013 have the same shape. The opening area of ​​the first hole segment 4011 is smaller than the opening area of ​​the second hole segment 4012, and the opening area of ​​the second hole segment 4012 is smaller than the opening area of ​​the third hole segment 4013. Figure 6 and Figure 7 As shown, before riveting, there are gaps between the second column 220 and the first hole section 4011 and the second hole section 4012, and the gap between the second column 220 and the second hole section 4012 is larger; further combined Figure 9 As shown, after riveting, the second column portion 220 expands in a direction away from the center line of the column body 2, thereby filling the gap between the second column portion 220 and the rivet hole 401, and the outer peripheral size of the column segment corresponding to the second hole segment 4012 on the second column portion 220 is larger than the outer peripheral size of the column segment corresponding to the first hole segment 4011, thereby limiting the downward movement of the column body 2 relative to the riveting block 4, and further combining with the plate body 1 to limit the upward movement of the pole structure relative to the cover body 3, thereby achieving relative fixation between the pole structure, the riveting block 4 and the cover body 3.

[0088] It should be noted that the upper surface of the second column portion 220 is flush with the upper end surface of the second hole section 4012. After the pole structure is riveted, the pole structure and the riveting block 4 need to be welded. The welding position is as follows: Figure 9 As shown by the arrow "P", since the weld has a certain height, the third hole section 4013 is provided with a larger opening area, thereby forming a sink on the upper surface of the riveting block 4, which can ensure that the weld does not exceed the surface of the riveting block 4.

[0089] 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.

[0090] In one embodiment, the first plastic part 6 is an upper plastic and the second plastic part 7 is a lower plastic.

[0091] 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.

[0092] 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.

[0093] 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; a column connected to the upper side of the plate body, the column comprising a first column portion and a second column portion, the first column portion being fixedly connected between the plate body and the second column portion, the first column portion being adapted to be inserted into the pole hole on the cover body, the outer contour of the upper surface of the first column portion being the same as the outer contour of the bottom surface, and the cross-sectional area of ​​the first column portion gradually decreasing from bottom to top; The maximum dimension of the upper surface of the first column along the length direction is d, the maximum dimension of the bottom surface of the first column along the length direction is D, and the height of the first column along the vertical direction is h, wherein, 2. The pole according to claim 1, characterized in that The relationship between D and d is: 0.1mm≤Dd≤0.8mm; And / or, the height h of the first column portion in the vertical direction is in the range of: 3 mm ≤ h ≤ 6 mm; And / or, the maximum dimension D of the bottom surface of the first column portion along the length direction is in the range of: 4.5 mm ≤ D ≤ 30 mm.

3. The pole according to claim 1, characterized in that The outer contour of the bottom surface of the first column portion is a first contour line, the contour line of the orthographic projection of the upper surface of the first column portion on the plate body is a second contour line, and the second contour line has the same shape as the first contour line and is concentrically arranged.

4. The pole according to claim 3, characterized in that The positive projection of the second column on the plate body is a third contour line. The third contour line has the same shape as the second contour line, and the area enclosed by the third contour line is smaller than the area enclosed by the second contour line. The third contour line is concentrically arranged with the first contour line and the second contour line.

5. The pole according to claim 4, characterized in that: A first ring is formed between the first contour line and the third contour line. The width of the first ring is W, wherein W satisfies the relationship between D and d:

6. The pole according to claim 5, characterized in that The value range of the ring width W of the first ring is: 0.3mm≤W≤1mm.

7. The pole according to any one of claims 4 to 6, characterized in that The first contour line, the second contour line and the third contour line are all runway-shaped; Alternatively, the first contour line, the second contour line, and the third contour line are all circular.

8. The pole according to claim 7, characterized in that The first contour line is in a runway shape, and the maximum dimension of the first contour line along the width direction is A, wherein 4mm≤A≤20mm.

9. 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 8, wherein the plate body of the pole is located on a side of the cover body away from the rivet block, the first column portion is inserted into the pole hole, and the second column portion is inserted into the rivet hole; A sealing ring is provided between the first column portion and the pole hole.

10. A battery cell, characterized in that: include: a housing having an open end; a pole group, disposed in the housing; The cover plate assembly according to claim 9 is provided to cover the open end of the shell.

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