Battery cell cover plate assembly, battery cell and battery pack

Abstract

The invention relates to the technical field of batteries, and discloses a battery cell cover plate assembly, a battery cell and a battery pack, the battery cell cover plate assembly comprises a cover plate body, a pole column body and a pole column bottom plate; a mounting hole is formed in the cover plate body; the pole body is inserted into the mounting hole and extends out of the first surface of the cover plate body, a riveting body is arranged at one end, extending out of the first surface, of the pole body, a riveting groove is formed in the riveting body, the projection of the riveting body in the thickness direction is in a long circle shape, and the long circle shape comprises two first linear sections and two first arc sections; the distance between the farthest point of the first arc section and the corresponding groove wall of the riveting groove is L1, the radius of the first arc section is R, 0.15 < = L1 / R < = 0.25, and the pole bottom plate is connected with one end, deviating from the riveting groove, of the pole body and is arranged on a second surface, opposite to the first surface, of the cover plate body. By controlling the size relationship between the riveting groove and the first arc section on the pole body, the riveting strength can be improved, breakage caused by excessive riveting is avoided, and the riveting quality is improved.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a battery cover assembly, a battery cell and a battery pack. Background Art

[0002] With the continuous development of technology, users' requirements for new energy batteries are becoming increasingly higher. To improve the fast charging capability of battery cells, it is necessary to improve the current carrying capacity of the terminal. In thinner battery cells, to ensure the current carrying capacity of the terminal, the terminal body can be made into a long cylindrical structure and then connected to the terminal base plate.

[0003] However, the long cylindrical pole body is affected by its shape. When riveting, the contact area between the arc section of the pole body and the transition between the straight section and the arc section is small, resulting in uneven force, insufficient riveting strength, or excessive riveting, causing breakage and other problems, resulting in poor riveting quality. Summary of the Invention

[0004] In view of this, the present invention provides a battery cover assembly, a battery cell and a battery pack to solve the problem that the shape of the long cylindrical pole body affects the riveting quality.

[0005] In a first aspect, the present invention provides a battery cell cover assembly, comprising:

[0006] The cover body is provided with a mounting hole extending through the cover body in the thickness direction;

[0007] The pole body is inserted into the mounting hole and extends to the outside of the first surface of the cover body, and the end of the pole body extending out of the first surface has a rivet body, and a rivet groove is provided on the rivet body. The projection of the rivet body along the thickness direction is an oblong, and the oblong includes two first straight line segments and two first arc segments. The two first straight line segments are relatively spaced along the width direction of the cover body, and the two first arc segments are relatively spaced along the length direction of the cover body. The two first arc segments are respectively connected to the two ends of the first straight line segments on the same side. Along the length direction of the cover body, the distance between the farthest point of the first arc segment and the corresponding groove wall of the rivet groove is L1, and the radius of the first arc segment is R, satisfying 0.15≤L1 / R≤0.25;

[0008] The pole bottom plate is connected to an end of the pole body away from the rivet groove, and the pole bottom plate is arranged on a second surface of the cover body opposite to the first surface.

[0009] Beneficial Effects: The battery cover assembly of the present invention features a columnar structure with an oblong cross-section. Given the limited width of the cover, the oblong cross-section is larger than a conventional circular cross-section. This increases the current flow area of ​​the electrode, improving its current capacity and enabling the battery cover assembly with this electrode to meet the demands of larger capacity batteries and faster charging speeds. By controlling the radius of the first arc segment of the oblong rivet and the distance between the first arc segment and the wall of the rivet groove along the length of the cover within an appropriate range, the electrode body has an appropriate riveted contact area, evenly distributing force, ensuring sufficient riveting at the first arc segment, reducing the risk of material shortages, and improving riveting strength, resulting in high-quality rivets. If L1 / R is too small, the spacing between the first arc segment and the rivet groove is too small, which can easily cause material expansion, deformation of the electrode body, and the presence of hot spots after welding. If L1 / R is too large, the spacing between the first arc segment and the rivet groove is too large, which can easily lead to insufficient riveting material and low riveting strength.

[0010] In an optional embodiment, the notch profile of the rivet groove includes two second straight line segments and two second arc segments, the two second straight line segments are relatively spaced apart along the width direction of the cover plate body, and the two second arc segments are relatively spaced apart along the length direction of the cover plate body, and the two second arc segments are respectively connected to the two ends of the second straight line segments on the same side, the second arc segment is a major arc, and along the width direction of the cover plate body, the distance between the first straight line segment and the second straight line segment is L2, satisfying 0.5mm≤L2≤3mm.

[0011] Beneficial Effects: The rivet slot's opening forms a dumbbell-shaped structure with a narrower second straight segment and a wider second arc segment. This allows the rivet block to fully contact the pole body, creating a larger mechanical engagement area and improving riveting strength. By controlling the distance between the first and second straight segments within an appropriate range, sufficient riveting is achieved, preventing the rivet block from falling off while also saving space. If the value of L2 is too small, the rivet pressure is insufficient, and the rivet block is prone to falling off. If the value of L2 is too large, it takes up too much space.

[0012] In an optional embodiment, in the length direction of the cover body, the distance between the connection between the first straight line segment and the first arc segment and the connection between the adjacent second straight line segment and the second arc segment is L3, satisfying 0.25≤L3 / R≤0.4.

[0013] Beneficial Effect: By controlling the distance between the connection between the first straight segment and the first arc segment and the connection between the adjacent second straight segment and the second arc segment along the length of the cover body, a smooth transition between the two arc segments can be ensured, further improving riveting quality. If L3 / R is too small, the transition will be too narrow, which can easily cause material expansion, deformation of the pole body, and cracking defects in the weld. If L3 / R is too large, the riveting will be insufficient, resulting in poor pole body strength.

[0014] In an optional embodiment, the first arc segment is a semicircle, and the radius R of the first arc segment satisfies 2mm≤R≤12mm.

[0015] Beneficial effect: By controlling the radius of the first arc segment within an appropriate range, the flow capacity of the riveted body can be ensured, and the riveted body can be prevented from occupying too much space. Moreover, it can further ensure that the riveted body is fully riveted.

[0016] In an optional embodiment, the pole body further includes a first column and a second column connected along the thickness direction, the rivet body is connected to an end of the first column away from the second column, the second column is connected to the pole base plate, the orthographic projections of the first column and the second column along the thickness direction are both oblong, and the orthographic projection of the first column is located within the orthographic projection of the second column, so as to form a step surface at the connection between the first column and the second column, and the dimension of the step surface along the length direction of the cover body is L4, satisfying 1≤L4 / L1≤2.

[0017] Beneficial effect: The step surface is used for riveting support. By controlling L4 / L1 within a suitable range, sufficient riveting pressure can be ensured, preventing the riveted block from falling off, while saving space.

[0018] In an optional embodiment, the battery cell cover assembly further includes a first insulating member and a rivet block, wherein the rivet block is connected to the rivet body and the first column and is arranged corresponding to the first surface, and the first insulating member is clamped between the rivet block and the cover body.

[0019] Beneficial Effects: The first insulating member insulates the pole body, preventing the pole body from directly contacting the cover body and causing a short circuit. The rivet block is used to fix the pole body, which can resist external forces such as vibration and impact, and improve the installation stability of the pole body.

[0020] In an optional embodiment, the battery cell cover assembly also includes a sealing ring and a second insulating member, the second insulating member is attached to the second surface, the pole bottom plate is arranged on the side of the second insulating member away from the second surface, and the sealing ring is arranged on the outer peripheral wall of the second column and is clamped between the pole bottom plate and the second insulating member and between the second column and the cover body.

[0021] Beneficial Effects: The sealing ring improves the sealing of the cell cover assembly, reducing the risk of electrolyte leakage from the cell cover assembly. The second insulating member enhances support and also provides insulation, preventing direct contact between the cell and the cover body.

[0022] In an optional embodiment, the pole bottom plate is in an elongated strip shape, and the riveted body, the first column and the second column extend along the length direction and the width direction of the pole bottom plate respectively.

[0023] Beneficial effect: The riveted body, the first column and the second column are extended along the length direction and the width direction of the pole bottom plate respectively, which facilitates the uniform distribution of current, reduces resistance and heat consumption, and is conducive to dispersing stress and improving the structural strength of the pole body.

[0024] In a second aspect, the present invention further provides a battery cell, comprising:

[0025] a housing having an opening at at least one end;

[0026] In the above-mentioned battery cell cover assembly, the cover body is arranged to cover the opening and is connected to the shell.

[0027] Beneficial effect: Because the battery cell includes a battery cell cover plate assembly, it has the same effect as the battery cell cover plate assembly, that is, the pole body adopts a columnar structure with an oblong cross-section. Under the premise that the width of the cover plate body is limited, the area of ​​the oblong cross-section is greater than the area of ​​the traditional circular cross-section, thereby increasing the flow area of ​​the pole body and improving the flow capacity, so that the battery cell cover plate assembly with the pole body can meet the use requirements of batteries with larger capacity and faster charging speed. By controlling the radius of the first arc segment of the oblong shape of the riveted body and the distance between the first arc segment and the groove wall of the riveted groove along the length direction of the cover plate body within a suitable range, the pole body has a suitable riveted contact area and uniform force, ensuring that the first arc segment is fully riveted, which can reduce the risk of material shortage, improve the riveting strength, and have a high riveting quality. If L1 / R is too small, the distance between the first arc segment and the riveted groove is too small, which can easily cause material expansion, resulting in deformation of the pole body and the presence of explosive point defects after welding. If L1 / R is too large, the distance between the first arc segment and the rivet groove is too large, which may easily lead to insufficient riveting material and low riveting strength.

[0028] In a third aspect, the present invention further provides a battery pack comprising: at least one of the above-mentioned battery cells.

[0029] Beneficial effects: Since the battery pack includes battery cells, it has the same effects as the battery cells and will not be elaborated 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 structural schematic diagram of a battery cell cover assembly according to an embodiment of the present invention;

[0032] Figure 2 An exploded view of a battery cell cover assembly according to an embodiment of the present invention;

[0033] Figure 3 This is a structural schematic diagram of a pole body and a pole bottom plate of a battery cell cover plate assembly according to an embodiment of the present invention;

[0034] Figure 4 for Figure 3 A top view of

[0035] Figure 5 This is a partial cross-sectional view of a battery cell cover assembly according to an embodiment of the present invention.

[0036] Description of reference numerals:

[0037] 1. Cover plate body; 101. Mounting hole; 2. Pole body; 201. Riveted groove; 2011. First straight segment; 2012. First arc segment; 2013. Second straight segment; 2014. Second arc segment; 202. Riveted body; 203. First column; 204. Second column; 205. Step surface; 3. Pole bottom plate; 4. First insulating member; 5. Riveted block; 6. Sealing ring; 7. Second insulating member. DETAILED DESCRIPTION

[0038] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0039] The following combination Figures 1 to 5 , describing embodiments of the present invention.

[0040] According to an embodiment of the present invention, on the one hand, Figure 1 and Figure 2 As shown, a cell cover assembly is provided, comprising: a cover body 1, a pole body 2 and a pole bottom plate 3. The cover body 1 is provided with a mounting hole 101 extending through the cover body 1 in the thickness direction. The pole body 2 is inserted into the mounting hole 101 and extends to the outside of the first surface of the cover body 1. One end of the pole body 2 extending out of the first surface has a rivet body 202, and a rivet groove 201 is opened on the rivet body 202. The projection of the rivet body 202 along the thickness direction is an oblong, and the oblong includes two first straight line segments 2011 and two first arc segments 2012. The two first straight line segments 2011 are relatively spaced apart along the width direction of the cover body 1, and the two first arc segments 2012 are relatively spaced apart along the length direction of the cover body 1. The two first arc segments 2012 are respectively connected to the two ends of the first straight line segments 2011 on the same side. Along the length direction of the cover body 1, the distance between the farthest point of the first arc segment 2012 and the corresponding groove wall of the rivet groove 201 is L1, and the radius of the first arc segment 2012 is R, satisfying 0.15≤L1 / R≤0.25. The pole bottom plate 3 is connected to the end of the pole body 2 away from the rivet groove 201 . The pole bottom plate 3 is provided on the second surface of the cover body 1 opposite to the first surface.

[0041] Thus, the cell cover plate assembly provided by the embodiment of the present invention features a columnar structure with an oblong cross-section. Given the limited width of the cover plate body 1, the oblong cross-section is larger than a conventional circular cross-section. This increases the current flow area of ​​the cell body 2 and improves its current flow capacity, enabling the cell cover plate assembly incorporating this cell body 2 to meet the demands of larger capacity cells and faster charging speeds. Along the length of the cover plate body 1, the area between the first arc segment 2012 and the corresponding wall of the rivet groove 201 is the weakest area of ​​the cell body 2. By controlling the radius of the oblong first arc segment 2012 of the rivet body 202 and the distance between the first arc segment 2012 and the wall of the rivet groove 201 along the length of the cover plate body 1 within an appropriate range, the cell body 2 has an appropriate riveted contact area, evenly distributes force, and ensures sufficient riveting at the first arc segment 2012, i.e., sufficient riveting at the weakest area. This reduces the risk of material shortages and improves riveting strength, resulting in high-quality rivets. If L1 / R is too small, the distance between the first arc segment 2012 and the rivet groove 201 is too small, which can easily cause material expansion, deformation of the pole body 2, and the presence of hot spots after welding. If L1 / R is too large, the distance between the first arc segment 2012 and the rivet groove 201 is too large, which can easily lead to insufficient rivet material and low rivet strength.

[0042] Specifically, the thickness direction of the cover body 1 is as follows: Figure 1 As shown by the arrow H in FIG, the length direction of the cover body 1 is as follows Figure 1 As shown by the arrow L in FIG, the width direction of the cover body 1 is as shown in FIG. Figure 1 As shown by the arrow W in FIG. , the rivet groove 201 is opened at the center of one end surface of the pole body 2 to ensure uniform force. Along the length direction of the cover body 1, the farthest point of the first arc segment 2012 is also the midpoint of the first arc segment 2012.

[0043] It should be noted that the battery cell cover assembly of this embodiment is applied to the blade battery. The cover body 1 of the blade battery has a large aspect ratio, that is, the length of the cover body 1 is large and the width is small. At present, the industry has increasingly higher requirements for the charge and discharge rates of batteries, which requires the current capacity of the pole body 2 to increase, that is, the cross-sectional area of ​​the pole body 2 needs to be increased. In the prior art, the cross-section of the pole body 2 is usually circular. Since the width of the cover body 1 of the blade battery is relatively small, it is not convenient to increase the diameter of the circle. Therefore, two cylindrical poles are usually set in the prior art to increase the current capacity. Such a setting results in a complicated assembly process of the cover assembly and low assembly efficiency. In the present embodiment, the pole body 2 is set to an oblong shape, and its size along the length direction of the cover body 1 is increased, which can not only improve the current capacity, but also does not need to increase the number of pole bodies 2, thereby ensuring assembly efficiency.

[0044] It should be noted that, in this embodiment, the size of the pole body 2 along the length direction of the cover body 1 needs to be increased as much as possible. Under the premise that the width of the cover body 1 is limited, the cross-sectional area of ​​the pole body 2 is also increased as much as possible to increase the flow area of ​​the pole body 2, thereby having good flow capacity.

[0045] In one embodiment, Figure 4 As shown, the notch profile of the rivet groove 201 includes two second straight segments 2013 and two second arc segments 2014. The two second straight segments 2013 are spaced apart along the width of the cover plate body 1, and the two second arc segments 2014 are spaced apart along the length of the cover plate body 1. The two second arc segments 2014 connect to the ends of the second straight segments 2013 on the same side. The second arc segments 2014 are major arcs, meaning that the distance between the two second straight segments 2013 is less than their diameter. Along the width of the cover plate body 1, the distance between the first straight segment 2011 and the second straight segment 2013 is L2, satisfying the condition 0.5 mm ≤ L2 ≤ 3 mm.

[0046] The notch of the rivet groove 201 forms a dumbbell-shaped structure with a narrow second straight segment 2013 and a wide second arc segment 2014. This allows the rivet block 5 to fully contact the pole body 2, creating a larger mechanical engagement area and improving riveting strength. By controlling the distance between the first straight segment 2011 and the second straight segment 2013 within an appropriate range, sufficient riveting is achieved, preventing the rivet block 5 from falling off, while also saving space. If the value of L2 is too small, the riveting pressure is insufficient, and the rivet block 5 is prone to falling off. If the value of L2 is too large, it will occupy a large space.

[0047] In addition, the groove wall of the rivet groove 201 is inclined inwardly and the groove bottom area is smaller than the groove opening area, so that the rivet groove 201 as a whole forms a groove with a dumbbell-shaped structure.

[0048] It should be noted that in this embodiment, the distance L2 between the first straight segment 2011 and the second straight segment 2013 along the width direction of the cover body 1 refers to the dimension after riveting, which is equivalent to the width of the press edge after riveting. The first straight segment 2011 and the second straight segment 2013 can be arranged in parallel.

[0049] In one embodiment, Figure 4 As shown, in the length direction of the cover body 1, the distance between the connection between the first straight line segment 2011 and the first arc segment 2012 and the connection between the adjacent second straight line segment 2013 and the second arc segment 2014 is L3, satisfying 0.25≤L3 / R≤0.4.

[0050] By controlling the distance between the junction of the first straight segment 2011 and the first arc segment 2012, and the junction of the adjacent second straight segment 2013 and the second arc segment 2014 along the length of the cover body 1, a smooth transition between the two arc segments can be ensured, further improving riveting quality. If L3 / R is too small, the transition will be too narrow, which can easily cause material expansion, deformation of the pole body 2, and cracking defects in the weld. If L3 / R is too large, the riveting will be insufficient, resulting in poor strength of the pole body 2.

[0051] Furthermore, in one embodiment, Figure 4 As shown, the first arc segment 2012 is semicircular, and the radius R of the first arc segment 2012 satisfies 2mm≤R≤12mm. By controlling the radius of the first arc segment 2012 within an appropriate range, the flow capacity of the riveted body 202 can be ensured, and the riveted body 202 can be prevented from occupying too much space. Furthermore, the riveted body 202 can be further ensured to be fully riveted.

[0052] Furthermore, along the length direction of the cover plate body 1 , the distance L1 between the farthest point of the first arc segment 2012 and the corresponding groove wall of the rivet groove 201 satisfies 0.3 mm≤L1≤3 mm.

[0053] Furthermore, in the length direction of the cover body 1, the spacing L3 between the connection point of the first straight line segment 2011 and the first arc segment 2012 and the connection point of the adjacent second straight line segment 2013 and the second arc segment 2014 satisfies 0.5mm≤L3≤4.8mm, for example, R is 2mm, L3 is 0.5mm, L3 / R is 0.25, or R is 7mm, L3 is 2.8mm, and L3 / R is 0.4.

[0054] In one embodiment, Figure 3 and Figure 5 As shown, the pole body 2 further includes a first column 203 and a second column 204 connected along the thickness direction. The rivet 202 is connected to the end of the first column 203 away from the second column 204. The second column 204 is connected to the pole base plate 3. The orthographic projections of the first column 203 and the second column 204 along the thickness direction are both oblong, and the orthographic projection of the first column 203 is located within the orthographic projection of the second column 204. This forms a step surface 205 at the junction of the first column 203 and the second column 204. The dimension of the step surface 205 along the length direction of the cover body 1 is L4, satisfying 1≤L4 / L1≤2. The step surface 205 provides riveting support. By controlling L4 / L1 within an appropriate range, sufficient riveting pressure can be ensured, preventing the riveted block 5 from falling off, while also saving space.

[0055] Furthermore, the dimension L4 of the step surface 205 along the length direction of the cover body 1 satisfies 0.3mm≤L4≤6mm, for example, L1 is 0.3mm, L4 is 0.3mm, L4 / L1 is 1, or L1 is 1mm, L4 is 2mm, L4 / L1 is 2, or L1 is 2mm, L4 is 3mm, L4 / L1 is 1.5.

[0056] In one embodiment, Figure 1 and Figure 2 As shown, the cell cover assembly also includes a first insulating member 4 and a rivet block 5. The rivet block 5 is connected to the rivet body 202 and the first column 203 and is arranged corresponding to the first surface. The first insulating member 4 is sandwiched between the rivet block 5 and the cover body 1. The first insulating member 4 is used to insulate the pole body 2, preventing the pole body 2 from directly contacting the cover body 1 and causing a short circuit. The rivet block 5 is used to secure the pole body 2, can resist external forces such as vibration and impact, and improve the installation stability of the pole body 2.

[0057] In one embodiment, Figure 1 and Figure 2As shown, the cell cover assembly also includes a sealing ring 6 and a second insulating member 7. The second insulating member 7 is attached to the second surface, and the pole base plate 3 is located on the side of the second insulating member 7 away from the second surface. The sealing ring 6 is sleeved on the outer peripheral wall of the second column 204 and is sandwiched between the pole base plate 3 and the second insulating member 7, as well as between the second column 204 and the cover body 1. The sealing ring 6 is used to improve the sealing of the cell cover assembly and reduce the risk of electrolyte leakage from the cell through the cell cover assembly. The second insulating member 7 can enhance the support effect and also provide insulation to prevent direct contact between the cell and the cover body 1.

[0058] In one embodiment, Figure 3 As shown, the pole base plate 3 is elongated, and the riveted body 202, the first column 203, and the second column 204 extend along the length and width of the pole base plate 3, respectively. Extending the riveted body 202, the first column 203, and the second column 204 along the length and width of the pole base plate 3, respectively, facilitates uniform current distribution, reduces resistance and heat loss, and helps disperse stress, thereby improving the structural strength of the pole body 2.

[0059] It should be noted that the embodiment of the present invention does not limit the material of the cover body 1 , and any existing material can be selected as needed. For example, the cover body 1 is a plain aluminum plate.

[0060] The process parameters of the battery according to the embodiment of the present invention are further described in detail below in conjunction with specific examples. These examples should not be construed as limiting the scope of protection claimed by the present invention.

[0061] Example 1:

[0062] The radius R of the first arc segment 2012 is 2 mm. Along the length of the cover body 1, the distance L1 between the furthest point of the first arc segment 2012 and the corresponding wall of the rivet groove 201 is 0.3 mm. Along the length of the cover body 1, the distance L3 between the junction of the first straight segment 2011 and the first arc segment 2012 and the junction of the adjacent second straight segment 2013 and the second arc segment 2014 is 0.65 mm. Therefore, L1 / R = 0.15, and L3 / R = 0.325. The results of testing and verification on the battery cell production line are shown in Table 1.

[0063] Example 2:

[0064] The radius R of the first arc segment 2012 is 4 mm. Along the length of the cover body 1, the distance L1 between the furthest point of the first arc segment 2012 and the corresponding wall of the rivet groove 201 is 0.7 mm. Along the length of the cover body 1, the distance L3 between the junction of the first straight segment 2011 and the first arc segment 2012 and the junction of the adjacent second straight segment 2013 and the second arc segment 2014 is 1.06 mm. Therefore, L1 / R = 0.175, and L3 / R = 0.265. The results of testing and verification on the battery cell production line are shown in Table 1.

[0065] Example 3:

[0066] The radius R of the first arc segment 2012 is 5.5 mm. Along the length of the cover body 1, the distance L1 between the furthest point of the first arc segment 2012 and the corresponding wall of the rivet groove 201 is 1.2 mm. Along the length of the cover body 1, the distance L3 between the junction of the first straight segment 2011 and the first arc segment 2012 and the junction of the adjacent second straight segment 2013 and the second arc segment 2014 is 1.45 mm. Therefore, L1 / R = 0.218, and L3 / R = 0.264. The results of testing and verification on the battery cell production line are shown in Table 1.

[0067] Example 4:

[0068] The radius R of the first arc segment 2012 is 8 mm. Along the length of the cover body 1, the distance L1 between the furthest point of the first arc segment 2012 and the corresponding wall of the rivet groove 201 is 1.8 mm. Along the length of the cover body 1, the distance L3 between the junction of the first straight segment 2011 and the first arc segment 2012 and the junction of the adjacent second straight segment 2013 and the second arc segment 2014 is 2.85 mm. Therefore, L1 / R = 0.225, and L3 / R = 0.356. The results of testing and verification on the battery cell production line are shown in Table 1.

[0069] Example 5:

[0070] The radius R of the first arc segment 2012 is 9.6 mm. Along the length of the cover body 1, the distance L1 between the furthest point of the first arc segment 2012 and the corresponding wall of the rivet groove 201 is 1.6 mm. Along the length of the cover body 1, the distance L3 between the junction of the first straight segment 2011 and the first arc segment 2012 and the junction of the adjacent second straight segment 2013 and the second arc segment 2014 is 2.68 mm. Therefore, L1 / R = 0.167, and L3 / R = 0.279. The results of testing and verification on the battery cell production line are shown in Table 1.

[0071] Example 6:

[0072] The radius R of the first arc segment 2012 is 7.8 mm. Along the length of the cover body 1, the distance L1 between the furthest point of the first arc segment 2012 and the corresponding wall of the rivet groove 201 is 1.2 mm. Along the length of the cover body 1, the distance L3 between the junction of the first straight segment 2011 and the first arc segment 2012 and the junction of the adjacent second straight segment 2013 and the second arc segment 2014 is 2.29 mm. Therefore, L1 / R = 0.154, and L3 / R = 0.294. The results of testing and verification on the battery cell production line are shown in Table 1.

[0073] Example 7:

[0074] The radius R of the first arc segment 2012 is 3.2 mm. Along the length of the cover body 1, the distance L1 between the furthest point of the first arc segment 2012 and the corresponding wall of the rivet groove 201 is 0.7 mm. Along the length of the cover body 1, the distance L3 between the junction of the first straight segment 2011 and the first arc segment 2012 and the junction of the adjacent second straight segment 2013 and the second arc segment 2014 is 1.18 mm. Therefore, L1 / R = 0.219, and L3 / R = 0.369. The results of testing and verification on the battery cell production line are shown in Table 1.

[0075] Example 8:

[0076] The radius R of the first arc segment 2012 is 5 mm. Along the length of the cover body 1, the distance L1 between the furthest point of the first arc segment 2012 and the corresponding wall of the rivet groove 201 is 0.86 mm. Along the length of the cover body 1, the distance L3 between the junction of the first straight segment 2011 and the first arc segment 2012 and the junction of the adjacent second straight segment 2013 and the second arc segment 2014 is 1.35 mm. Therefore, L1 / R = 0.172, and L3 / R = 0.27. The results of testing and verification on the battery cell production line are shown in Table 1.

[0077] Example 9:

[0078] The radius R of the first arc segment 2012 is 11.6 mm. Along the length of the cover body 1, the distance L1 between the furthest point of the first arc segment 2012 and the corresponding wall of the rivet groove 201 is 2.2 mm. Along the length of the cover body 1, the distance L3 between the junction of the first straight segment 2011 and the first arc segment 2012 and the junction of the adjacent second straight segment 2013 and the second arc segment 2014 is 3.85 mm. Therefore, L1 / R = 0.19, and L3 / R = 0.332. The results of testing and verification on the battery cell production line are shown in Table 1.

[0079] Example 10:

[0080] The radius R of the first arc segment 2012 is 10 mm. Along the length of the cover body 1, the distance L1 between the furthest point of the first arc segment 2012 and the corresponding wall of the rivet groove 201 is 1.8 mm. Along the length of the cover body 1, the distance L3 between the junction of the first straight segment 2011 and the first arc segment 2012 and the junction of the adjacent second straight segment 2013 and the second arc segment 2014 is 2.62 mm. Therefore, L1 / R = 0.18, and L3 / R = 0.262. The results of testing and verification on the battery cell production line are shown in Table 1.

[0081] Comparative Example 1:

[0082] The radius R of the first arc segment 2012 is 8.5 mm. Along the length of the cover body 1, the distance L1 between the furthest point of the first arc segment 2012 and the corresponding wall of the rivet groove 201 is 1.1 mm. Along the length of the cover body 1, the distance L3 between the junction of the first straight segment 2011 and the first arc segment 2012 and the junction of the adjacent second straight segment 2013 and the second arc segment 2014 is 2.76 mm. Therefore, L1 / R = 0.129, which is less than 0.15, and L3 / R = 0.325. The results of testing and verification on the battery cell production line are shown in Table 1.

[0083] Comparative Example 2:

[0084] The radius R of the first arc segment 2012 is 4.3 mm. Along the length of the cover body 1, the distance L1 between the furthest point of the first arc segment 2012 and the corresponding wall of the rivet groove 201 is 0.34 mm. Along the length of the cover body 1, the distance L3 between the junction of the first straight segment 2011 and the first arc segment 2012 and the junction of the adjacent second straight segment 2013 and the second arc segment 2014 is 1.25 mm. Therefore, L1 / R = 0.079, which is less than 0.15, and L3 / R = 0.291. The results of testing and verification on the battery cell production line are shown in Table 1.

[0085] Comparative Example 3:

[0086] The radius R of the first arc segment 2012 is 9.2 mm. Along the length of the cover body 1, the distance L1 between the furthest point of the first arc segment 2012 and the corresponding wall of the rivet groove 201 is 2.8 mm. Along the length of the cover body 1, the distance L3 between the junction of the first straight segment 2011 and the first arc segment 2012 and the junction of the adjacent second straight segment 2013 and the second arc segment 2014 is 2.93 mm. Therefore, L1 / R = 0.304, which is greater than 0.25, and L3 / R = 0.318. The results of testing and verification on the battery cell production line are shown in Table 1.

[0087] Comparative Example 4:

[0088] The radius R of the first arc segment 2012 is 5.6 mm. Along the length of the cover body 1, the distance L1 between the furthest point of the first arc segment 2012 and the corresponding wall of the rivet groove 201 is 3.2 mm. Along the length of the cover body 1, the distance L3 between the junction of the first straight segment 2011 and the first arc segment 2012 and the junction of the adjacent second straight segment 2013 and the second arc segment 2014 is 1.54 mm. Therefore, L1 / R = 0.571, which is greater than 0.25, and L3 / R = 0.275. The results of testing and verification on the battery cell production line are shown in Table 1.

[0089] Comparative Example 5:

[0090] The radius R of the first arc segment 2012 is 7.3 mm. Along the length of the cover body 1, the distance L1 between the furthest point of the first arc segment 2012 and the corresponding wall of the rivet groove 201 is 1.13 mm. Along the length of the cover body 1, the distance L3 between the junction of the first straight segment 2011 and the first arc segment 2012 and the junction of the adjacent second straight segment 2013 and the second arc segment 2014 is 1.43 mm. Therefore, L1 / R = 0.155, and L3 / R = 0.196, which are less than 0.25. The results of testing and verification on the battery cell production line are shown in Table 1.

[0091] Comparative Example 6:

[0092] The radius R of the first arc segment 2012 is 4.7 mm. Along the length of the cover body 1, the distance L1 between the furthest point of the first arc segment 2012 and the corresponding wall of the rivet groove 201 is 0.82 mm. Along the length of the cover body 1, the distance L3 between the junction of the first straight segment 2011 and the first arc segment 2012 and the junction of the adjacent second straight segment 2013 and the second arc segment 2014 is 0.82 mm. Therefore, L1 / R = 0.174, and L3 / R = 0.174, which are less than 0.25. The results of testing and verification on the battery cell production line are shown in Table 1.

[0093] Comparative Example 7:

[0094] The radius R of the first arc segment 2012 is 9.2 mm. Along the length of the cover body 1, the distance L1 between the furthest point of the first arc segment 2012 and the corresponding wall of the rivet groove 201 is 1.62 mm. Along the length of the cover body 1, the distance L3 between the junction of the first straight segment 2011 and the first arc segment 2012 and the junction of the adjacent second straight segment 2013 and the second arc segment 2014 is 4.25 mm. Therefore, L1 / R = 0.176, and L3 / R = 0.462, both exceeding 0.4. The results of testing and verification on the battery cell production line are shown in Table 1.

[0095] Comparative Example 8:

[0096] The radius R of the first arc segment 2012 is 10.6 mm. Along the length of the cover body 1, the distance L1 between the furthest point of the first arc segment 2012 and the corresponding wall of the rivet groove 201 is 2.53 mm. Along the length of the cover body 1, the distance L3 between the junction of the first straight segment 2011 and the first arc segment 2012 and the junction of the adjacent second straight segment 2013 and the second arc segment 2014 is 6.8 mm. Therefore, L1 / R = 0.239, and L3 / R = 0.642, both exceeding 0.4. The results of testing and verification on the battery cell production line are shown in Table 1.

[0097] Table 1: Test results

[0098]

[0099] As can be seen from Table 1, in Examples 1 to 10, 2 mm ≤ R ≤ 12 mm, 0.15 ≤ L1 / R ≤ 0.25, and 0.25 ≤ L3 / R ≤ 0.4 are satisfied. The riveting is sufficient, and the riveting strength of the pole body 2 is good, meeting the riveting requirements.

[0100] In Comparative Examples 1 and 2, L1 / R is less than 0.15, which is lower than the minimum value of the embodiment of the present invention. The spacing between the first arc segment 2012 and the rivet groove 201 is too small, and the weak area is too narrow, which easily causes expansion of the material, resulting in deformation of the pole body 2, and explosion point defects after welding.

[0101] In Comparative Examples 3 and 4, L1 / R is greater than 0.25, exceeding the maximum value of the embodiment of the present invention. The distance between the first arc segment 2012 and the rivet groove 201 is too large, which easily leads to insufficient riveting material and low riveting strength.

[0102] In Comparative Examples 5 and 6, L3 / R is less than 0.25, which is lower than the minimum value of the embodiment of the present invention. The transition between the two arc segments is too narrow, which easily causes material expansion, resulting in deformation of the pole body 2 and explosion defects in the welding.

[0103] In Comparative Examples 7 and 8, L3 / R is greater than 0.4, exceeding the maximum value of the embodiment of the present invention. The transition between the two arc segments is too wide, resulting in insufficient riveting and poor strength of the pole body 2.

[0104] According to another aspect of an embodiment of the present invention, a battery cell is provided, comprising a housing and a cell cover assembly. The housing has an opening at at least one end, and a pole group is disposed within the housing. A cover body 1 of the cell cover assembly is disposed over the opening and is connected to the housing.

[0105] In the battery cell provided by the embodiments of the present invention, the pole body 2 adopts a cylindrical structure with an oblong cross-section. Given the limited width of the cover body 1, the area of ​​the oblong cross-section is greater than that of a conventional circular cross-section. This increases the flow area of ​​the pole body 2 and improves the flow capacity, enabling the battery cell cover assembly incorporating this pole body 2 to meet the demands of larger capacity batteries and faster charging speeds. By controlling the radius of the oblong first arc segment 2012 of the rivet body 202 and the distance between the first arc segment 2012 and the wall of the rivet groove 201 along the length of the cover body 1 within an appropriate range, the pole body 2 has an appropriate riveted contact area, uniformly applies force, ensures sufficient riveting at the first arc segment 2012, reduces the risk of material shortages, improves riveting strength, and achieves high riveting quality. If L1 / R is too small, the spacing between the first arc segment 2012 and the rivet groove 201 is too small, which can easily cause material expansion, deformation of the pole body 2, and the presence of hot spots after welding. If L1 / R is too large, the distance between the first arc segment 2012 and the rivet groove 201 is too large, which may easily lead to insufficient riveting material and low riveting strength.

[0106] According to another aspect of an embodiment of the present invention, a battery pack is provided, comprising: at least one battery cell.

[0107] Since the battery pack includes battery cells and has the same effect as the battery cells, it will not be described in detail here.

[0108] 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 battery cover assembly, characterized in that: include: The cover body is provided with a mounting hole extending through the cover body in the thickness direction; The pole body is inserted into the mounting hole and extends to the outside of the first surface of the cover body, and the end of the pole body extending out of the first surface has a rivet body, and a rivet groove is provided on the rivet body. The projection of the rivet body along the thickness direction is an oblong, and the oblong includes two first straight line segments and two first arc segments. The two first straight line segments are relatively spaced along the width direction of the cover body, and the two first arc segments are relatively spaced along the length direction of the cover body. The two first arc segments are respectively connected to the two ends of the first straight line segments on the same side. Along the length direction of the cover body, the distance between the farthest point of the first arc segment and the corresponding groove wall of the rivet groove is L1, and the radius of the first arc segment is R, satisfying 0.15≤L1 / R≤0.25; The pole bottom plate is connected to an end of the pole body away from the rivet groove, and the pole bottom plate is arranged on a second surface of the cover body opposite to the first surface.

2. The battery cover assembly according to claim 1, characterized in that: The notch profile of the rivet groove includes two second straight line segments and two second arc segments. The two second straight line segments are relatively spaced apart along the width direction of the cover plate body, and the two second arc segments are relatively spaced apart along the length direction of the cover plate body. The two second arc segments are respectively connected to the two ends of the second straight line segments on the same side. The second arc segment is a major arc. Along the width direction of the cover plate body, the distance between the first straight line segment and the second straight line segment is L2, satisfying 0.5mm≤L2≤3mm.

3. The battery cover assembly according to claim 2, characterized in that: In the length direction of the cover plate body, a distance between a connection point between the first straight line segment and the first arc segment and a connection point between the adjacent second straight line segment and the second arc segment is L3, satisfying 0.25≤L3 / R≤0.

4.

4. The battery cover assembly according to claim 3, characterized in that: The first arc segment is a semicircle, and the radius R of the first arc segment satisfies 2mm≤R≤12mm.

5. The battery cell cover assembly according to any one of claims 1 to 4, characterized in that: The pole body also includes a first column and a second column connected along the thickness direction, the rivet body is connected to an end of the first column away from the second column, and the second column is connected to the pole base plate. The orthographic projections of the first column and the second column along the thickness direction are both oblong, and the orthographic projection of the first column is located within the orthographic projection of the second column, so as to form a step surface at the connection between the first column and the second column. The dimension of the step surface along the length direction of the cover body is L4, satisfying 1≤L4 / L1≤2.

6. The battery cover assembly according to claim 5, characterized in that: The cell cover assembly further includes a first insulating member and a rivet block. The rivet block is connected to the rivet body and the first column and is arranged corresponding to the first surface. The first insulating member is sandwiched between the rivet block and the cover body.

7. The battery cover assembly according to claim 6, characterized in that: The battery cell cover assembly also includes a sealing ring and a second insulating member, the second insulating member is attached to the second surface, the pole bottom plate is arranged on the side of the second insulating member away from the second surface, and the sealing ring is sleeved on the outer peripheral wall of the second column and clamped between the pole bottom plate and the second insulating member and between the second column and the cover body.

8. The battery cover assembly according to claim 5, characterized in that: The pole bottom plate is in an elongated strip shape, and the riveted body, the first column and the second column extend along the length direction and the width direction of the pole bottom plate respectively.

9. A battery cell, characterized in that: include: a housing having an opening at at least one end; The battery cell cover assembly according to any one of claims 1 to 8, wherein the cover body is arranged to cover the opening and is connected to the shell.

10. A battery pack, characterized in that: include: At least one battery cell according to claim 9.

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