Cell cover assembly, cell and battery pack

Abstract

This utility model relates to the field of battery technology and discloses a cell cover assembly, a cell, and a battery pack. The cell cover assembly includes: a riveting block with a riveting hole; along the thickness direction of the cover, the riveting block has an annular protrusion surrounding the riveting hole on the side facing the cover; and a terminal post including a riveting section and a limiting section, the connection between the riveting section and the limiting section forming a first annular stepped surface. The riveting section passes through the annular protrusion and the riveting hole, and the annular protrusion abuts against the first annular stepped surface. This utility model, by providing an annular protrusion on the side of the riveting block facing the cover for abutting against the first annular stepped surface on the terminal post, increases the distance between the side of the riveting block facing the cover and the first annular stepped surface, thereby reducing the force transmitted from the end of the riveting section away from the limiting section to the vicinity of the first annular stepped surface during riveting, and reducing the possibility of deformation of the first annular stepped surface due to excessive force.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a cell cover assembly, a cell, and a battery pack. Background Technology

[0002] In current cell cover assembly designs, after the riveting block in the cell cover assembly is riveted to the electrode post, the stepped surface on the electrode post becomes the supporting surface of the bottom of the riveting block along the thickness direction of the cover. However, since the electrode post is usually made of copper, aluminum, or copper-aluminum composite materials, although these materials have good conductivity, their structural strength is relatively poor. Therefore, when the riveting part of the electrode post undergoes plastic deformation under external force, the electrode post itself is relatively soft and cannot withstand high pressure. As a result, the stepped surface of the electrode post is prone to deformation or collapse, which in turn leads to the collapse of the riveting block connected to the electrode post. Utility Model Content

[0003] In view of this, the present invention provides a cell cover plate assembly and a cell to solve the problem in the prior art where the stepped surface on the electrode post collapses due to stress during the riveting process, causing the riveting block to also collapse.

[0004] In a first aspect, this utility model provides a battery cell cover assembly, comprising:

[0005] The cover plate is equipped with clearance holes;

[0006] A rivet block is provided on one side of the cover plate. The rivet block has a rivet hole. Along the thickness direction of the cover plate, the side of the rivet block facing the cover plate has an annular protrusion surrounding the rivet hole.

[0007] The pole includes a riveting section and a limiting section. The connection between the riveting section and the limiting section forms a first annular stepped surface. The riveting section passes through the clearance hole so that it is inserted into the annular protrusion and the riveting hole. At least a portion of the limiting section is inserted into the clearance hole. The annular protrusion abuts against the first annular stepped surface.

[0008] Beneficial Effects: Compared to related solutions where the side of the riveting block facing the cover plate directly abuts against the stepped surface on the pole, this invention, by providing an annular protrusion on the side of the riveting block facing the cover plate for abutting against the first annular stepped surface on the pole, increases the distance between the side of the riveting block facing the cover plate and the first annular stepped surface, extending the length of the riveting segment itself. This reduces the force transmitted from the end of the riveting segment away from the limiting section to the vicinity of the first annular stepped surface during riveting, lowering the possibility of deformation of the first annular stepped surface due to excessive force. This, in turn, ensures the relative stability of the position of the riveting block and other components in the cell cover plate assembly, such as the aluminum sheet. Furthermore, since the riveting segment, under riveting pressure, not only tends to deform downwards but also laterally, by providing an annular protrusion over the riveting segment between the side of the riveting block facing the cover plate and the first annular stepped surface, the annular protrusion provides lateral support to that part of the riveting segment, reducing the possibility of pole collapse due to excessive deformation.

[0009] In one optional embodiment, along the thickness direction of the cover plate, the orthographic projection of the annular protrusion toward the first annular step surface falls within the range of the annular step surface; along the thickness direction perpendicular to the cover plate, the width of the first annular step surface is c, and the value of c ranges from 0.3mm ≤ c ≤ 3mm.

[0010] Beneficial Effects: This invention sets the orthographic projection of the annular protrusion toward the first annular step surface within the range of the first annular step surface, and limits the width c of the first annular step surface to between 0.3mm and 3mm, ensuring precise and stable contact and fit between the annular protrusion and the first annular step surface. Secondly, the orthographic projection of the annular protrusion falling within the range of the first annular step surface allows for uniform distribution of riveting pressure on the annular step surface, avoiding stress concentration that could lead to localized deformation or damage, thereby improving the reliability of the battery cell cover assembly structure. Furthermore, a reasonable width range for the first annular step surface not only reduces the processing difficulty of the first annular step surface but also ensures sufficient contact area between the annular protrusion and the first annular step surface, ensuring that the first annular step surface can provide sufficient support for the riveting block. In addition, limiting the width c of the first annular step surface to between 0.3mm and 3mm also avoids material waste or structural redundancy due to excessive width.

[0011] In one optional embodiment, the riveting hole includes a first through hole and a second through hole that are connected to each other. The diameter of the first through hole is larger than the diameter of the second through hole, and a second annular step surface is formed at the connection between the first through hole and the second through hole. The riveting section includes a main riveting section and a secondary riveting section. The main riveting section is located in the first through hole and is riveted to the first through hole. The secondary riveting section is located in the second through hole and the annular protrusion and is riveted to both of them.

[0012] Beneficial effects: This invention enlarges the diameter of the first through hole and rivets the main riveting section to the first through hole, which not only increases the contact area between them but also enhances the connection strength between the electrode and the riveting block, reducing the possibility of separation during subsequent use of the battery cell. Secondly, by riveting the secondary riveting section to the second through hole and the annular protrusion, this invention further enhances the connection strength between other parts of the electrode and the riveting block, thereby increasing the electrode's load-bearing capacity in the thickness direction of the battery cell cover assembly and preventing separation of the electrode from the riveting block when subjected to forces along the thickness direction of the battery cell cover assembly. Furthermore, because the electrode deforms downwards and laterally under riveting pressure, a portion of the riveting section abuts against the second annular step surface during riveting, thus limiting the electrode's position in the thickness direction of the battery cell cover assembly.

[0013] In one optional embodiment, along the thickness direction perpendicular to the cover plate, the abutment width between the main riveting section and the second annular step surface is f, where f ranges from 0.2mm ≤ f ≤ 1mm.

[0014] Beneficial effects: If the value of f is less than 0.2 mm, it will increase the difficulty of forming the second annular step surface on the one hand, and cause the contact area between the main riveting section and the second annular step surface to be too small, affecting the limiting effect of the second annular step surface on the pole post on the other hand. If the value of f is greater than 1 mm, it means that the reserved gap between the outer wall of the riveting section and the hole wall of the first through hole is relatively large before riveting. Therefore, there will be a situation where the preset deformation of the riveting section is less than the above-mentioned reserved gap, thus failing to achieve the purpose of riveting the main riveting section and the first through hole.

[0015] In one optional embodiment, along the thickness direction of the cover plate, the upper surface of the riveting block is provided with a welding groove that surrounds and communicates with the first through hole, and the bottom surface of the welding groove is flush with the surface of the riveting section away from the limiting section.

[0016] Beneficial Effects: This invention, by providing a welding groove on the upper surface of the riveting block, offers two advantages. First, it provides a relatively ample welding area for welding the electrode and the riveting block, reducing the difficulty of the welding operation. Second, it stores excess solder during the welding process, preventing solder from overflowing onto the upper surface of the riveting block. Furthermore, the bottom surface of the welding groove is flush with the surface of the end of the riveting section furthest from the limiting section, ensuring a smooth connection surface after welding, reducing stress concentration, and enhancing the stability of the connection structure. Secondly, this flush design also helps reduce contact resistance, improves conductivity, and ensures efficient current conduction between the electrode and the riveting block, thereby improving the overall safety and reliability of the battery cell.

[0017] In one optional embodiment, along the thickness direction of the cover plate, the distance between the bottom surface of the welding groove and the second annular step surface is e, and the value of e ranges from 0.8mm ≤ e ≤ 2mm.

[0018] Beneficial effects: The value of 'e' directly determines the longitudinal space of the first through hole in the thickness direction of the cell cover assembly, which in turn determines the fillable thickness of the main riveting section within the first through hole. Therefore, if the value of 'e' is less than 0.8 mm, the thickness of the main riveting section filled in the first through hole will be smaller, the mechanical strength of the electrode will decrease, and the electrode will be prone to breakage or deformation during cell use. If the value of 'e' is greater than 2 mm, although sufficient fillable space can be reserved, the longitudinal space that the main riveting section needs to fill during riveting is too large, and the electrode material may exceed its plastic limit due to excessive deformation, leading to problems such as difficulty in material expansion and uneven material flow during riveting.

[0019] In one optional embodiment, along the thickness direction perpendicular to the cover plate, the outer wall of the riveting section away from the limiting section is welded to the inner wall of the first through hole to form a weld mark, and the depth of the weld mark along the thickness direction of the cover plate is g, where the value of g is 0.3mm≤g≤e.

[0020] Beneficial effects: This invention limits g to the range of 0.3mm to e, which ensures sufficient contact area at the welding interface, reduces contact resistance, and guarantees reliable current conduction. It also prevents excessive solder penetration from damaging the riveting structure, achieving dual optimization in both mechanical connection and conductivity between the electrode and the riveting block. Specifically, if g is less than 0.3mm, it means insufficient solder depth, resulting in a small welding contact area between the electrode and the riveting block, narrowing the current conduction path, causing internal resistance fluctuations or even localized heating, affecting the cell's conductivity stability. If g is greater than e, it means the solder will exceed the preset welding range and reach non-welded areas of the riveting block, such as the second annular step surface. This not only creates excess solder accumulation on the riveting block, damaging its structural strength and surface flatness, but also allows solder to penetrate into the abutment gap between the electrode and the second annular step surface, destroying the mechanical locking structure originally formed by the riveting connection.

[0021] In one optional embodiment, a riveting groove is formed on the surface of the riveting section away from the limiting section. Along the thickness direction of the cover plate, the cross-sectional shape of the riveting groove is an inverted trapezoid, wherein the included angle formed by the two inclined sides of the inverted trapezoid is A, and the value of A is 30°≤A≤120°.

[0022] And / or, along the thickness direction of the cover plate, the length of the limiting segment is d, and the value of d is in the range of 0.5mm≤d≤2mm.

[0023] Beneficial effects: If the value of A is less than 30°, it means the opening of the riveting groove is too narrow, which will lead to uneven expansion of the electrode post during the riveting process, making it impossible to completely fill the riveting groove, thus affecting the firmness of the riveting and the structural stability of the battery. If the value of A is greater than 120°, it means the opening of the riveting groove is too wide, which will cause the electrode post to expand excessively in all directions during the riveting process, causing deformation of the riveting block, thus affecting the structural integrity and reliability of the battery. Therefore, this invention controls the included angle A within the range of 30° to 120°, which can ensure that the opening size of the riveting groove is moderate, which is beneficial to the uniform expansion of the electrode post and the stable riveting of the electrode post to the riveting block.

[0024] Furthermore, since the cover plate is made of metal, an insulating component needs to be installed around the pole to prevent short circuits between the cover plate and the pole. This invention sets the length d of the limiting segment to 0.5mm ≤ d ≤ 2mm, thus forming a stable and reliable positioning structure. Specifically, a sufficiently long limiting segment can fully contact the insulating component, increasing the friction and contact area between them, making it less prone to displacement or tilting of the insulating component during installation.

[0025] Secondly, this utility model also provides a battery cell, comprising:

[0026] The pole assembly has a pole tab at one end;

[0027] In the aforementioned cell cover assembly, the end of the limiting section away from the riveting section is provided with a pole post base, the pole post base is located outside the clearance hole, and the pole post base is welded to the electrode tab.

[0028] Beneficial effects: The battery cell of this utility model includes the battery cell cover assembly as described above, and has all the beneficial technical effects of the battery cell cover assembly, which will not be repeated here.

[0029] Thirdly, this utility model also provides a battery pack, comprising: a plurality of the above-mentioned battery cells.

[0030] Beneficial effects: The battery pack of this utility model includes the battery cell as described above, and has all the beneficial technical effects of the battery cell, which will not be repeated here. Attached Figure Description

[0031] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0032] Figure 1 This is a front view of a battery cell cover assembly according to an embodiment of the present utility model;

[0033] Figure 2 for Figure 1 An exploded view of the battery cell cover assembly shown in the figure;

[0034] Figure 3 for Figure 1 A cross-sectional view of the cell cover assembly shown;

[0035] Figure 4 for Figure 3 A magnified view of part M in the diagram;

[0036] Figure 5 for Figure 1 The cross-sectional view of the rivet block shown.

[0037] Explanation of reference numerals in the attached figures:

[0038] 1. Riveting block; 101. Riveting hole; 1011. First through hole; 1012. Second through hole; 1013. Second annular step surface; 102. Annular protrusion; 103. Welding groove; 2. Pole post; 201. Riveting section; 2011. Main riveting section; 2012. Secondary riveting section; 202. Limiting section; 203. First annular step surface; 204. Riveting groove; 205. Pole post base; 3. Cover plate; 301. Clearance hole; 4. Insulating component; 5. Weld mark. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0040] In view of the problem that the stepped surface on the pole collapses due to stress during the riveting process in the prior art, causing the riveting block to also collapse, this utility model provides a cell cover plate assembly, a cell, and a battery pack.

[0041] The following is combined Figures 1 to 5 The following describes embodiments of the present invention.

[0042] According to embodiments of the present invention, on the one hand, such as Figures 1 to 4 As shown, a battery cell cover assembly is provided, including: a cover plate 3, a riveting block 1, and an electrode post 2.

[0043] Specifically, the cover plate 3 is provided with a clearance hole 301; the riveting block 1 is provided on one side of the cover plate 3, the riveting block 1 is provided with a riveting hole 101, and along the thickness direction of the cover plate 3, the side of the riveting block 1 facing the cover plate 3 is provided with an annular protrusion 102 surrounding the riveting hole 101; the pole post 2 includes a riveting section 201 and a limiting section 202, the connection between the riveting section 201 and the limiting section 202 forms a first annular stepped surface 203, the riveting section 201 passes through the clearance hole 301 so that it passes through the annular protrusion 102 and the riveting hole 101, at least a part of the limiting section 202 passes through the clearance hole 301, and the annular protrusion 102 abuts against the first annular stepped surface 203.

[0044] Compared to related solutions where the side of the riveting block 1 facing the cover plate 3 directly abuts against the stepped surface on the pole post 2, this utility model embodiment provides an annular protrusion 102 on the side of the riveting block 1 facing the cover plate 3 for abutting against the first annular stepped surface 203 on the pole post 2. This increases the distance between the side of the riveting block 1 facing the cover plate 3 and the first annular stepped surface 203, extending the length of the riveting section 201. In this way, the force transmitted from the end of the riveting section 201 away from the limiting section 202 to the vicinity of the first annular stepped surface 203 during the riveting process can be reduced, reducing the possibility of the first annular stepped surface 203 deforming due to excessive force. This, in turn, ensures the relative stability of the riveting block 1 and other components in the battery cell cover assembly, such as the aluminum sheet. Furthermore, since the riveting section 201 has a tendency to deform downwards and also to deform to its circumference after being subjected to riveting pressure, by providing an annular protrusion 102 over the riveting section 201 between the side of the riveting block 1 facing the cover plate 3 and the first annular step surface 203, the annular protrusion 102 can provide lateral support for this part of the riveting section 201, reducing the possibility of the pole post 2 collapsing due to excessive deformation.

[0045] It should be noted that, in addition, the annular protrusion 102 in this embodiment can be integrally formed with the rivet block 1 or separately formed from the rivet block 1. Preferably, the annular protrusion 102 is integrally formed with the rivet block 1, which not only reduces the manufacturing difficulty but also improves the connection stability between the two. For example, along the thickness direction of the cover plate 3, the wall of the rivet hole 101 extends downward and protrudes from the side of the rivet block 1 facing the cover plate 3 to form an annular protrusion 102 connected to the bottom surface of the rivet block 1. It can be understood that, in order to ensure sufficient contact area between the annular protrusion 102 and the first annular step surface 203, the wall thickness of the annular protrusion 102 can be made to a specified thickness as needed.

[0046] According to one embodiment of the present invention, such as Figure 4As shown, along the thickness direction of the cover plate 3, the orthographic projection of the annular protrusion 102 toward the first annular step surface 203 falls within the range of the annular step surface; along the thickness direction perpendicular to the cover plate 3, the width of the first annular step surface 203 is c, and the value of c ranges from 0.3mm ≤ c ≤ 3mm. This embodiment of the invention sets the orthographic projection of the annular protrusion 102 toward the first annular step surface 203 within the range of the first annular step surface 203, and limits the width c of the first annular step surface 203 to between 0.3mm and 3mm, which ensures precise and stable contact between the annular protrusion 102 and the first annular step surface 203. Secondly, the fact that the orthographic projection of the annular protrusion 102 falls within the range of the first annular step surface 203 allows the riveting pressure to be evenly distributed on the annular step surface, avoiding stress concentration that could lead to localized deformation or damage, thereby improving the reliability of the battery cell cover assembly structure. Furthermore, a reasonable width range for the first annular step surface 203 not only reduces the processing difficulty of the first annular step surface 203 but also ensures sufficient contact area between the annular protrusion 102 and the first annular step surface 203, ensuring that the first annular step surface 203 can provide sufficient support for the riveting block 1. In addition, limiting the width c of the first annular step surface 203 to between 0.3mm and 3mm also avoids material waste or structural redundancy due to excessive width.

[0047] It should be noted that the width c of the first annular step surface 203 can be, but is not limited to, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, and 3mm.

[0048] According to one embodiment of the present invention, such as Figure 4 and Figure 5As shown, the riveting hole 101 includes a first through hole 1011 and a second through hole 1012 that are connected. The diameter of the first through hole 1011 is larger than the diameter of the second through hole 1012. The connection between the first through hole 1011 and the second through hole 1012 forms a second annular stepped surface 1013. The riveting section 201 includes a main riveting section 2011 and a secondary riveting section 2012. The main riveting section 2011 is located inside the first through hole 1011 and is riveted to the first through hole 1011. The secondary riveting section 2012 is located inside the second through hole 1012 and the annular protrusion 102 and is riveted to both. In this embodiment of the invention, the diameter of the first through hole 1011 is increased, and the main riveting section 2011 is riveted to the first through hole 1011. This not only increases the contact area between the two but also improves the connection strength between the electrode post 2 and the riveting block 1, reducing the possibility of separation during subsequent use of the battery cell. Secondly, in this embodiment of the invention, the secondary riveting section 2012 is riveted to the second through hole 1012 and the annular protrusion 102, which can also improve the connection strength between the pole post 2 and the riveting block 1 at other positions. This can improve the load-bearing capacity of the pole post 2 in the thickness direction of the cell cover assembly and prevent the pole post 2 from separating from the riveting block 1 when subjected to a force along the thickness direction of the cell cover assembly. In addition, since the pole post 2 will deform downward and circumferentially after being subjected to riveting pressure, part of the structure of the riveting section 201 will abut against the second annular step surface 1013 during the riveting process, thus limiting the pole post 2 in the thickness direction of the cell cover assembly.

[0049] According to one embodiment of the present invention, such as Figure 4 As shown, along the thickness direction perpendicular to the cover plate 3, the contact width between the main riveting section 2011 and the second annular step surface 1013 is f, where f ranges from 0.2mm to 1mm. If f is less than 0.2mm, it will increase the difficulty of forming the second annular step surface 1013 and result in a small contact area between the main riveting section 2011 and the second annular step surface 1013, affecting the limiting effect of the second annular step surface 1013 on the pole post 2. If f is greater than 1mm, it means that the reserved gap between the outer wall of the riveting section 201 and the hole wall of the first through hole 1011 is relatively large before riveting. Therefore, there may be a situation where the preset deformation of the riveting section 201 is less than the above-mentioned reserved gap, thus failing to achieve the purpose of riveting the main riveting section 2011 and the first through hole 1011.

[0050] It is understandable that, since the main riveting section 2011 is riveted to the first through hole 1011, the contact width f between the main riveting section 2011 and the second annular step surface 1013 is the width of the second annular step surface 1013 itself.

[0051] It should be noted that the value of f can be, but is not limited to, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, and 1mm.

[0052] In one embodiment, such as Figure 4 As shown, along the thickness direction of the cover plate 3, the length of the riveting segment 201 passing through the annular protrusion 102 and the second through hole 1012 is b, and the value of b is in the range of 3mm ≤ b ≤ 5mm. It can be understood that the length of the riveting segment 201 passing through the annular protrusion 102 and the second through hole 1012 affects the distance between the side of the riveting block 1 facing the cover plate 3 and the first annular step surface 203. Therefore, if the value of b is less than 3mm, it is not conducive to reducing the impact of riveting pressure on the first annular step surface 203; while if the value of b is greater than 3mm, it will excessively occupy the space in the thickness direction of the cell cover plate assembly, affecting the energy density of the cell. Therefore, in this embodiment, setting the value of b to 3mm ≤ b ≤ 5mm not only avoids excessive deformation or collapse of the first annular step surface 203 during riveting, but also makes the overall structure of the cell cover plate assembly more compact.

[0053] It should be noted that the value of b can be, but is not limited to, 3mm, 3.5mm, 4mm, 4.5mm, and 5mm.

[0054] According to one embodiment of the present invention, such as Figure 4 and Figure 5 As shown, along the thickness direction of the cover plate 3, the upper surface of the riveting block 1 is provided with a welding groove 103 that surrounds and communicates with the first through hole 1011. The bottom surface of the welding groove 103 is flush with the surface of the riveting section 201 away from the limiting section 202. By providing the welding groove 103 on the upper surface of the riveting block 1, this embodiment of the invention provides a relatively sufficient welding operation area for welding the electrode post 2 and the riveting block 1, reducing the difficulty of the welding operation. Furthermore, it can store excess solder during the welding process, preventing solder from overflowing onto the upper surface of the riveting block 1. In addition, the flushness of the bottom surface of the welding groove 103 with the surface of the riveting section 201 away from the limiting section 202 ensures a smooth connection surface after welding, reducing stress concentration and enhancing the stability of the connection structure. Moreover, this flush design also helps to reduce contact resistance, improve conductivity, and ensure efficient current conduction between the electrode post 2 and the riveting block 1, thereby improving the overall safety and reliability of the battery cell.

[0055] According to one embodiment of the present invention, such as Figure 4As shown, along the thickness direction of the cover plate 3, the distance between the bottom surface of the welding groove 103 and the second annular step surface 1013 is e, and the value of e ranges from 0.8mm ≤ e ≤ 2mm. The size of e directly determines the longitudinal space of the first through hole 1011 in the thickness direction of the cell cover plate assembly, which in turn determines the fillable thickness of the main riveting section 2011 in the first through hole 1011. Therefore, if the value of e is less than 0.8mm, the thickness of the main riveting section 2011 filled in the first through hole 1011 will be smaller, the mechanical strength of the pole post 2 will decrease, and the pole post 2 will be prone to breakage or deformation during the use of the cell. If the value of e is greater than 2mm, although sufficient fillable space can be reserved, the longitudinal space that the main riveting section 2011 needs to fill during the riveting process is too large, and the material of the pole post 2 may exceed its plastic limit due to excessive deformation, resulting in problems such as difficulty in material expansion and uneven material flow during riveting.

[0056] It should be noted that the value of e can be, but is not limited to, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, and 2mm.

[0057] According to one embodiment of the present invention, such as Figure 4 As shown, along the thickness direction perpendicular to the cover plate 3, the outer wall of the riveting section 201 away from the limiting section 202 is welded to the inner wall of the first through hole 1011 to form a weld mark 5. The depth of the weld mark 5 along the thickness direction of the cover plate is g, and the value of g ranges from 0.3mm ≤ g ≤ e. This embodiment of the invention limits g to the range of 0.3mm to e, which ensures sufficient contact area at the welding interface, reduces contact resistance, guarantees reliable current conduction, and avoids damage to the riveting structure caused by excessive solder penetration. This achieves dual optimization in both mechanical connection and electrical conductivity between the pole post 2 and the riveting block 1. Specifically, if g is less than 0.3mm, it means that the depth of the solder mark 5 is insufficient, which will result in a small welding contact area between the pole post 2 and the riveting block 1, narrowing the current conduction path, thereby causing internal resistance fluctuations or even local heating, affecting the conductivity stability of the battery cell; if g is greater than e, it means that the solder will exceed the preset welding range and reach the non-welding area of ​​the riveting block 1, such as the second annular step surface 1013. In this way, not only will excess solder accumulate on the riveting block 1, damaging its structural strength and surface flatness, but the solder will also penetrate into the abutment gap between the pole post 2 and the second annular step surface 1013, destroying the mechanical locking structure originally formed by the riveting fit.

[0058] According to one embodiment of the present invention, such as Figure 3 and Figure 4As shown, a riveting groove 204 is formed on the surface of the riveting section 201 away from the limiting section 202. Along the thickness direction of the cover plate 3, the cross-sectional shape of the riveting groove 204 is an inverted trapezoid, wherein the included angle formed by the two inclined sides of the inverted trapezoid is A, and the value of A is 30°≤A≤120°. If the value of A is less than 30°, it means that the opening of the riveting groove 204 is too narrow, which will cause uneven expansion of the electrode post 2 during the riveting process, and it will not be able to completely fill the riveting groove 204, thus affecting the firmness of the riveting and the structural stability of the battery. If the value of A is greater than 120°, it means that the opening of the riveting groove 204 is too wide, which will cause the electrode post 2 to expand excessively to all sides during the riveting process, causing deformation of the riveting block 1, thus affecting the structural integrity and reliability of the battery. As can be seen, by controlling the included angle A within the range of 30° to 120° in this embodiment of the utility model, it can ensure that the opening size of the riveting groove 204 is moderate, which is conducive to the uniform expansion of the pole post 2 and the stable riveting of the pole post 2 and the riveting block 1.

[0059] Specifically, such as Figure 4 As shown, along the thickness direction of the cover plate 3, the distance between the bottom surface of the riveting groove 204 and the opening of the riveting groove 204 in this embodiment is 'a', and the value of 'a' ranges from 0.8mm to 2mm. This ensures that the pole post 2 expands uniformly during the riveting process.

[0060] It should be noted that the value of A can be, but is not limited to, 30°, 40°, 50°, 60°, 70°, 80°, 90°, 100°, 110°, and 120°; the value of a can be, but is not limited to, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, and 2mm.

[0061] According to one embodiment of the present invention, such as Figure 4 As shown, the length of the limiting segment 202 along the thickness direction of the cover plate 3 is d, and the value of d ranges from 0.5mm to 2mm. Since the battery cell cover plate assembly also includes a cover plate made of metal, an insulating component 4 needs to be installed on the electrode post 2 to avoid short circuits between the cover plate and the electrode post 2. In this embodiment of the invention, the length d of the limiting segment 202 is set to 0.5mm to 2mm, which can form a stable and reliable positioning structure. Specifically, a sufficiently long limiting segment 202 can fully contact the insulating component 4, increasing the friction and contact area between the two, making it less likely for the insulating component 4 to shift or tilt during installation.

[0062] It is understood that the value of d can be, but is not limited to, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, and 2mm.

[0063] It should be noted that the material of the insulating component 4 can be, but is not limited to, epoxy resin, polypropylene, and nylon.

[0064] According to an embodiment of the present invention, another aspect provides a battery cell, comprising: an electrode assembly and the aforementioned battery cell cover plate assembly.

[0065] Specifically, one end of the electrode assembly is provided with an electrode tab; the end of the limiting section 202 in the above-mentioned cell cover plate assembly away from the riveting section 201 is provided with an electrode post base 205, the electrode post base 205 is located outside the clearance hole 301, and the electrode post base 205 is welded to the electrode tab.

[0066] In one embodiment, the electrode assembly includes a plurality of alternately arranged positive and negative electrode plates and a separator disposed between the positive and negative electrode plates. Specifically, the positive electrode plate includes a positive current collector and a positive active material disposed on at least one surface of the positive current collector. As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the opposite surfaces of the positive current collector. As an example, the positive current collector can be a metal foil, a foamed metal, or a composite current collector. For example, as a metal foil, silver-surfaced aluminum or stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium, etc., can be used. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. The composite current collector may include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming metallic materials (aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer substrate (such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.). As an example, the positive electrode active material may include at least one of the following: lithium phosphates, lithium transition metal oxides, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as battery positive electrode active materials may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphates include, but are not limited to, lithium iron phosphate (such as LiFePO4 (also abbreviated as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites, at least one of these.

[0067] In some embodiments, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector. As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the opposite surfaces of the negative electrode current collector. As an example, the negative electrode current collector may be a metal foil, a foamed metal, or a composite current collector. For example, as a metal foil, silver-treated aluminum or stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, or titanium, etc., may be used. The composite current collector may include a polymeric material base layer and a metal layer. The foamed metal may be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymeric material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.). As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc.

[0068] In some embodiments, the separator is a separator membrane. This application does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected. As an example, the main material of the separator membrane can be selected from at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramics.

[0069] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0070] It should be further noted that the electrode tabs in this embodiment include positive electrode tabs and negative electrode tabs. The positive electrode tab is formed by the portion of the positive electrode plate that does not contain active material, and the negative electrode tab is formed by the portion of the negative electrode plate that does not contain active material. The negative electrode tab and the positive electrode tab can be located together at one end of the electrode assembly or separately at both ends of the electrode assembly.

[0071] According to an embodiment of the present invention, another aspect provides a battery pack comprising a plurality of the aforementioned battery cells.

[0072] The battery pack of this utility model includes the battery cell described above, and has all the beneficial technical effects of the battery cell, which will not be repeated here.

[0073] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. An electrochemical cell cover plate assembly, comprising: include: The cover plate is equipped with clearance holes; A rivet block is provided on one side of the cover plate. The rivet block has a rivet hole. Along the thickness direction of the cover plate, the side of the rivet block facing the cover plate has an annular protrusion surrounding the rivet hole. The pole includes a riveting section and a limiting section. The connection between the riveting section and the limiting section forms a first annular stepped surface. The riveting section passes through the clearance hole so that it is inserted into the annular protrusion and the riveting hole. At least a portion of the limiting section is inserted into the clearance hole. The annular protrusion abuts against the first annular stepped surface.

2. The cell cover plate assembly of claim 1, wherein, Along the thickness direction of the cover plate, the orthographic projection of the annular protrusion toward the first annular step surface falls within the range of the annular step surface; along the thickness direction perpendicular to the cover plate, the width of the first annular step surface is c, and the value of c is in the range of 0.3mm≤c≤3mm.

3. The cell cover assembly according to claim 1, characterized in that, The riveting hole includes a first through hole and a second through hole that are connected. The diameter of the first through hole is larger than the diameter of the second through hole. The connection between the first through hole and the second through hole forms a second annular step surface. The riveting section includes a main riveting section and a secondary riveting section. The main riveting section is located in the first through hole and is riveted to the first through hole. The secondary riveting section is located in the second through hole and the annular protrusion and is riveted to both of them.

4. The cell cover plate assembly of claim 3, wherein, Along the thickness direction perpendicular to the cover plate, the contact width between the main riveting section and the second annular step surface is f, and the value of f ranges from 0.2mm to f and from 1mm to f.

5. The cell cover plate assembly of claim 3, wherein, Along the thickness direction of the cover plate, the upper surface of the riveting block is provided with a welding groove that surrounds and communicates with the first through hole, and the bottom surface of the welding groove is flush with the surface of the riveting section away from the limiting section.

6. The cell cover plate assembly of claim 5, wherein, Along the thickness direction of the cover plate, the distance between the bottom surface of the welding groove and the second annular step surface is e, and the value of e ranges from 0.8mm ≤ e ≤ 2mm.

7. The cell cover plate assembly of claim 6, wherein, Along the thickness direction perpendicular to the cover plate, the outer wall of the riveting section away from the limiting section is welded to the inner wall of the first through hole to form a weld mark. Along the thickness direction of the cover plate, the depth of the weld mark is g, and the value of g is in the range of 0.3mm≤g≤e.

8. The cell cover plate assembly of any one of claims 1-7, wherein, A riveting groove is formed on the surface of the end of the riveting section away from the limiting section. Along the thickness direction of the cover plate, the cross-sectional shape of the riveting groove is an inverted trapezoid, wherein the included angle formed by the two inclined sides of the inverted trapezoid is A, and the value of A is 30°≤A≤120°. And / or, along the thickness direction of the cover plate, the length of the limiting segment is d, and the value of d is in the range of 0.5mm≤d≤2mm.

9. An electric cell characterized by include: The pole assembly has a pole tab at one end; According to any one of claims 1 to 8, the end of the limiting section away from the riveting section is provided with a pole post base, the pole post base is located outside the clearance hole, and the pole post base is welded to the pole tab.

10. A battery pack, characterized by, include: The battery cell as described in multiple claims 9.

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