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 and a sealing ring; a mounting hole is formed in the cover plate body; the pole is inserted into the mounting hole, the pole comprises a first pole body, a second pole body and a bottom plate which are connected in sequence, the projection of the second pole body in the thickness direction is dumbbell-shaped, and the dumbbell-shaped projection comprises two linear sections and two arc sections; the sealing ring is arranged on the peripheral wall of the second column body in a sleeving manner and is clamped between the second column body and the cover plate body; the reserved gap between the arc section and the inner wall of the sealing ring in the length direction of the cover plate body is L1, the reserved gap between the linear section and the inner wall of the sealing ring in the width direction of the cover plate body is L2, and the L1 is larger than or equal to 0.01 mm and smaller than or equal to 0.1 mm, and the L2 is larger than or equal to 0.04 mm and smaller than or equal to 0.2 mm. According to the cover plate, the second column body is arranged to be the dumbbell-shaped section, the expansion amount of the linear section can be reduced, the sealing effect of the sealing ring is improved, and the deformation risk of the cover plate body is reduced.

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, the current carrying capacity of the terminal needs to be improved. In thinner battery cells, to ensure the current carrying capacity of the terminal, the terminal can be made into a cylindrical structure with an oblong cross-section. The oblong cross-section usually consists of two straight segments and two circular segments at both ends.

[0003] When riveting a terminal, both the straight and arc segments require a certain amount of rivet pressure. These segments are typically riveted simultaneously, but due to their shapes, the amount of material expansion during riveting differs between the straight and arc segments. To ensure riveting quality, prioritizing the arc segments requires rivet pressure. However, this can lead to excessive material expansion in the straight segments, which can easily squeeze the sealing ring, affecting the sealing effect and even causing deformation of the cover plate itself. 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 when the pole with an oblong cross-section is riveted, due to the influence of its own shape, the expansion amount of the straight section is too large, which easily squeezes the sealing ring and even causes deformation of the cover body.

[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] A pole, inserted into the mounting hole, the pole comprising a first column, a second column and a bottom plate connected in sequence along the thickness direction, the first column extending to the first surface of the cover body, the bottom plate being provided on the second surface of the cover body opposite to the first surface, the projection of the second column along the thickness direction being a dumbbell shape, the dumbbell shape comprising two straight line segments and two arc segments, the two straight line segments being relatively spaced apart along the width direction of the cover body, the two arc segments being relatively spaced apart along the length direction of the cover body, the two arc segments being respectively connected to the two ends of the straight line segments on the same side, and the arc segments being major arcs;

[0008] a sealing ring, sleeved on the outer peripheral wall of the second column and sandwiched between the second column and the cover body;

[0009] Along the length direction of the cover body, the reserved gap between the arc segment and the inner wall of the sealing ring is L1, and along the width direction of the cover body, the reserved gap between the straight segment and the inner wall of the sealing ring is L2, satisfying 0.01mm≤L1≤0.1mm, 0.04mm≤L2≤0.2mm.

[0010] Beneficial effects: The battery cover assembly of the present invention has a dumbbell-shaped cross-section in which the second column of the pole has a larger flow area than the traditional circular cross-section, has good flow capacity, and is conducive to the use of large-capacity batteries and fast-charging cells. The reserved gap L1 between the straight section and the inner wall of the sealing ring and the reserved gap L2 between the arc section and the inner wall of the sealing ring are controlled within an appropriate range. On the basis of ensuring that the arc section has sufficient riveting pressure, the amount of expansion of the straight section is reduced, the sealing ring is avoided from being squeezed, the sealing effect is improved, and the risk of deformation of the cover body can be reduced. If L1 is too small, the sealing ring is easily skewed during assembly. If L1 is too large, the sealing gap is large and the sealing performance is poor. If L2 is too small, the amount of expansion of the straight section is too large during riveting, which is easy to squeeze the sealing ring and cause deformation of the cover body. If L2 is too large, the second pole is too concave, and a gap is easily formed between the sealing ring and the second column, resulting in poor sealing performance.

[0011] In an optional embodiment, the reserved gap L1 between the arc segment and the inner wall of the sealing ring along the length direction of the cover body and the reserved gap L2 between the straight segment and the inner wall of the sealing ring along the width direction of the cover body satisfy 0.03mm≤L2-L1≤0.1mm.

[0012] Beneficial Effect: By further controlling the difference between the reserved gap L2 and the reserved gap L1 within an appropriate range, the sealing reliability during riveting can be ensured. If the value of L2-L1 is too large, the gap between the sealing ring and the second column is large, resulting in poor sealing performance. If the value of L2-L1 is too small, the amount of material expansion in the straight section during riveting is too large, which can easily squeeze the sealing ring and cause deformation of the cover body.

[0013] In an optional embodiment, the two arc segments are connected to the two ends of the straight line segments on the same side through transition arc segments, and the two ends of the transition arc segments are tangent to the corresponding arc segments and the straight line segments respectively.

[0014] Beneficial effects: The transition arc segment is used to smoothly connect the arc segment and the straight segment, thereby achieving a smooth transition between the arc segment and the straight segment, which is beneficial to dispersing stress and improving the structural strength of the second column. At the same time, it is also convenient for installing the sealing ring, reducing the gap between the sealing ring and the straight segment, and ensuring the sealing performance.

[0015] In an optional embodiment, the distance between the centers of the two arc segments is L3, and the dimension of the straight line segment along the length direction of the cover plate body is L4, satisfying 0.2≤L4 / L3≤0.8.

[0016] Beneficial Effect: By controlling L4 / L3 within an appropriate range, the amount of expansion in the straight and transition arc segments can be maintained appropriately. If L4 / L3 is too small, the straight segment accounts for too little, the indentation is small, and the transition arc is too long. This causes a large expansion during the riveting process, which can easily squeeze the sealing ring and cause deformation of the cover body. If L4 / L3 is too large, the straight segment accounts for a small proportion, the indentation is large, the transition arc is too short, and the transition arc is too large along the length of the cover body, which can easily cause the sealing ring to be improperly assembled and pressed, resulting in poor sealing performance.

[0017] In an optional embodiment, the distance L3 between the centers of the two arc segments satisfies 1mm≤L3≤15mm.

[0018] Beneficial effect: By controlling the center distance between the two arc segments within an appropriate range, the sealing performance of the sealing ring can be further improved, and the deformation risk of the cover body can be reduced.

[0019] In an optional embodiment, the sealing ring is arranged with a constant wall thickness along the circumferential direction.

[0020] Beneficial effect: Setting the sealing ring with uniform wall thickness along the circumference can ensure that the sealing ring is evenly stressed during riveting, avoiding local stress concentration leading to sealing failure, and also facilitating the assembly of the sealing ring.

[0021] In an optional embodiment, the battery cell cover assembly further includes an upper insulating member and a rivet block, wherein the rivet block is connected to the first column and corresponding to the first surface, and the upper insulating member is clamped between the rivet block and the cover body.

[0022] Beneficial Effects: The upper insulator insulates the pole, preventing direct contact between the pole and the cover plate, which could cause a short circuit. The riveted block secures the pole, resisting external forces such as vibration and impact, and improving the stability of the pole installation.

[0023] In an optional embodiment, the battery cell cover plate assembly further includes a lower insulating member, which is attached to the second surface, the bottom plate is disposed on a side of the lower insulating member away from the second surface, and the sealing ring is further sandwiched between the bottom plate and the lower insulating member.

[0024] Beneficial effect: The lower insulating member can improve the supporting effect and is also used for insulation to prevent the battery cell from direct contact with the cover body.

[0025] In a second aspect, the present invention further provides a battery cell, comprising:

[0026] a housing having an opening at at least one end;

[0027] In the above-mentioned battery cell cover assembly, the cover body is arranged to cover the opening and is connected to the shell.

[0028] Beneficial effect: Because the battery cell includes a battery cell cover plate assembly, it has the same effect as the battery cell, that is, the second column of the pole has a dumbbell-shaped cross-section. Compared with the traditional circular cross-section, the flow area is larger and has good flow capacity, which is conducive to the use of large-capacity battery cells and fast-charging cells. The reserved gap L1 between the straight section and the inner wall of the sealing ring and the reserved gap L2 between the arc section and the inner wall of the sealing ring are controlled within an appropriate range. On the basis of ensuring that the arc section has sufficient riveting pressure, the expansion amount of the straight section is reduced, the sealing ring is avoided from being squeezed, the sealing effect is improved, and the risk of deformation of the cover plate body can be reduced. If L1 is too small, the sealing ring is easy to be skewed during assembly. If L1 is too large, the sealing gap is large and the sealing performance is poor. If L2 is too small, the expansion amount of the straight section is too large during riveting, which is easy to squeeze the sealing ring and cause deformation of the cover plate body. If L2 is too large, the second pole is too concave, and a gap is easily formed between the sealing ring and the second column, resulting in poor sealing performance.

[0029] In a third aspect, the present invention further provides a battery pack comprising: at least one of the above-mentioned battery cells.

[0030] 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

[0031] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1 This is a structural schematic diagram of a battery cell cover assembly according to an embodiment of the present invention;

[0033] Figure 2 An exploded view of a battery cell cover assembly according to an embodiment of the present invention;

[0034] Figure 3 This is a schematic diagram of a pole and a sealing ring of a battery cell cover assembly according to an embodiment of the present invention;

[0035] Figure 4 for Figure 3 A partial schematic diagram of

[0036] Figure 5 This is a schematic diagram of a pole of a battery cell cover assembly according to an embodiment of the present invention;

[0037] Figure 6 for Figure 5 Top view of .

[0038] Description of reference numerals:

[0039] This application: 1. Cover plate body; 101. Mounting hole; 2. Pole; 201. First column; 202. Second column; 2021. Straight segment; 2022. Arc segment; 2023. Transition arc segment; 203. Bottom plate; 3. Sealing ring; 4. Upper insulating member; 5. Riveted block; 6. Lower insulating member. DETAILED DESCRIPTION

[0040] 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.

[0041] The following combination Figures 1 to 6 , describing embodiments of the present invention.

[0042] According to an embodiment of the present invention, on the one hand, Figure 1 and Figure 2As shown, a cell cover assembly is provided, which mainly includes: a cover body 1, a pole 2 and a sealing ring 3. The cover body 1 is provided with a mounting hole 101 which is set through along the thickness direction. The pole 2 is inserted into the mounting hole 101. The pole 2 includes a first column 201, a second column 202 and a bottom plate 203 which are connected in sequence along the thickness direction. The first column 201 extends to the first surface of the cover body 1. The bottom plate 203 is provided on the second surface of the cover body 1 opposite to the first surface. The projection of the second column 202 along the thickness direction is a dumbbell shape. The dumbbell shape includes two straight segments 2021 and two circular arc segments 2022. The two straight segments 2021 are relatively spaced apart along the width direction of the cover body 1. The two circular arc segments 2022 are relatively spaced apart along the length direction of the cover body 1. The two circular arc segments 2022 are respectively connected to the two ends of the two straight segments 2021 on the same side. The circular arc segment 2022 is a major arc. The sealing ring 3 is sleeved around the outer wall of the second column 202 and sandwiched between the second column 202 and the cover body 1. Along the length of the cover body 1, the reserved gap L1 between the arc segment 2022 and the inner wall of the sealing ring 3 is provided. Along the width of the cover body 1, the reserved gap L2 between the straight segment 2021 and the inner wall of the sealing ring 3 is provided, satisfying the following conditions: 0.01mm≤L1≤0.1mm, and 0.04mm≤L2≤0.2mm.

[0043] It can be seen that in the battery cover assembly provided by the embodiment of the present invention, the second column 202 of the pole 2 has a dumbbell-shaped cross-section. Compared with the traditional circular cross-section, the flow area is larger and has good flow capacity, which is conducive to the use of large-capacity battery cells and fast-charging cells. The reserved gap L1 between the straight section 2021 and the inner wall of the sealing ring 3 and the reserved gap L2 between the arc section 2022 and the inner wall of the sealing ring 3 are controlled within a suitable range. On the basis of ensuring that the arc section 2022 has sufficient riveting pressure, the expansion amount of the straight section 2021 is reduced, the squeezing of the sealing ring 3 is avoided, the sealing effect is improved, and the risk of deformation of the cover body 1 can also be reduced. If L1 is too small, the sealing ring 3 is easy to be skewed during assembly. If L1 is too large, the sealing gap is large and the sealing performance is poor. If L2 is too small, the amount of material expansion of the straight section 2021 during riveting will be too large, which will easily squeeze the sealing ring 3 and cause deformation of the cover body 1. If L2 is too large, the second pole 2 will be too concave, and a gap will easily form between the sealing ring 3 and the second column 202, resulting in poor sealing performance.

[0044] Specifically, the thickness direction is also the height direction of the cover body 1, such as 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 1As shown by the arrow W in FIG. , the reserved gap L1 and the reserved gap L2 are both the dimensions before the sealing ring 3 is riveted to the pole 2. The arc segment 2022 is a major arc, that is, the diameter of the arc segment 2022 is greater than the distance between the two straight segments 2021.

[0045] Specifically, if Figure 3 and Figure 5 As shown, the projection of the first column 201 along the thickness direction is an oblong, and the projection of the first column 201 along the thickness direction falls within the projection of the second column 202 along the thickness direction. The connection between the first column 201 and the second column 202 forms a step surface, which is used to support and limit the rivet block 5. In addition, as shown in FIG. Figure 4 As shown, the sealing ring 3 has an oblong through hole, and the second column 202 is disposed in the through hole.

[0046] When the pole 2 is riveted, the flow rate is limited, in order to ensure the sealing performance of the sealing ring 3. In one embodiment, the reserved gap L1 between the arc segment 2022 and the inner wall of the sealing ring 3 along the length direction of the cover body 1 and the reserved gap L2 between the straight segment 2021 and the inner wall of the sealing ring 3 along the width direction of the cover body 1 meet 0.03mm≤L2-L1≤0.1mm. If the value of L2-L1 is too large, the gap between the sealing ring 3 and the second column 202 is large, resulting in poor sealing performance. If the value of L2-L1 is too small, the amount of expansion of the straight segment 2021 during riveting is too large, which is easy to squeeze the sealing ring 3 and cause the cover body 1 to deform.

[0047] It should be noted that if Figure 4 and Figure 6 As shown, along the length direction of the cover body 1, the reserved gap L1 between the arc segment 2022 and the inner wall of the sealing ring 3 can be uniform. Similarly, along the width direction of the cover body 1, the reserved gap L2 between the straight segment 2021 and the inner wall of the sealing ring 3 can be uniform. Then the value of L2-L1 is the maximum distance L5 between the outer edge of the arc segment 2022 and the straight segment 2021 along the width direction of the cover body 1, that is, 0.03mm≤L5≤0.1mm.

[0048] Illustratively, in an embodiment of the present invention, the value of L5 may be 0.03 mm, 0.05 mm, 0.08 mm, 0.1 mm, etc.

[0049] In one embodiment, Figure 4As shown, the two arc segments 2022 are connected to the two ends of the straight line segments 2021 on the same side through transition arc segments 2023. The ends of the transition arc segments 2023 are tangent to the corresponding arc segments 2022 and straight line segments 2021. The transition arc segments 2023 are used to smoothly connect the arc segments 2022 and the straight line segments 2021, achieving a smooth transition between the arc segments 2022 and the straight line segments 2021, which helps to disperse stress and improve the structural strength of the second column 202. It also facilitates the installation of the sealing ring 3, reduces the gap between the sealing ring 3 and the straight line segments 2021, and ensures sealing performance.

[0050] Furthermore, the transition arc segment 2023 includes a first sub-arc segment and a second sub-arc segment connected to each other, wherein one end of the first sub-arc segment is tangent to one end of the straight line segment 2021, the other end of the first sub-arc segment is tangent to one end of the second sub-arc segment, and the other end of the second sub-arc segment is tangent to the circular arc segment 2022.

[0051] In one embodiment, Figure 4 As shown, the distance between the centers of the two arc segments 2022 is L3, and the dimension of the straight segment 2021 along the length direction of the cover plate body 1 is L4, satisfying 0.2≤L4 / L3≤0.8. By controlling L4 / L3 within an appropriate range, the straight segment 2021 and the transition arc segment 2023 can be kept at an appropriate expansion amount. If L4 / L3 is too small, the proportion of the straight segment 2021 is too small, the concave amount is small, the transition arc segment 2023 is too long, and the expansion amount of the transition arc segment 2023 during the riveting process is large, which is easy to squeeze the sealing ring 3 and cause deformation of the cover plate body 1. If L4 / L3 is too large, the proportion of the straight segment 2021 is small, the concave amount is large, the transition arc segment 2023 is too short, and the dimension of the transition arc segment 2023 along the length direction of the cover plate body 1 is large, which is easy to cause poor assembly and pressing of the sealing ring 3, resulting in poor sealing performance.

[0052] Furthermore, in one embodiment, the center distance L3 of the two arc segments 2022 satisfies 1mm≤L3≤15mm. By controlling the center distance L3 of the two arc segments 2022 within an appropriate range, the sealing performance of the sealing ring 3 can be further improved and the deformation risk of the cover body 1 can be reduced.

[0053] In one embodiment, the sealing ring 3 has a uniform wall thickness along the circumference. This ensures that the sealing ring 3 is evenly stressed during riveting, preventing localized stress concentration that could lead to seal failure. It also facilitates assembly of the sealing ring 3. The uniform wall thickness of the sealing ring 3 along the circumference means that the thickness of the outer circumferential wall of the second column 202 on which the sealing ring 3 is mounted is uniformly distributed.

[0054] In one embodiment, Figure 1 and Figure 2As shown, the cell cover assembly also includes an upper insulator 4 and a rivet block 5. The rivet block 5 is connected to the first column 201 and is arranged corresponding to the first surface. The upper insulator 4 is sandwiched between the rivet block 5 and the cover body 1. The upper insulator 4 is used to insulate the pole 2 to prevent the pole 2 from directly contacting the cover body 1 and causing a short circuit. The rivet block 5 is used to fix the pole 2 and can resist external forces such as vibration and impact, thereby improving the installation stability of the pole 2. The upper insulator 4 and the rivet block 5 can protrude from the first surface, in which case the first column 201 extends beyond the first surface.

[0055] In one embodiment, Figure 1 and Figure 2 As shown, the cell cover assembly further includes a lower insulating member 6, which is attached to the second surface. The bottom plate 203 is disposed on a side of the lower insulating member 6 away from the second surface. The sealing ring 3 is further sandwiched between the bottom plate 203 and the lower insulating member 6. The lower insulating member 6 can enhance the support effect and also serves as insulation to prevent direct contact between the cell and the cover body 1.

[0056] 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.

[0057] 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.

[0058] Example 1:

[0059] Along the length of the cover body 1, the reserved gap L1 between the arc segment 2022 and the inner wall of the sealing ring 3 is 0.025mm. Along the width of the cover body 1, the reserved gap L2 between the straight segment 2021 and the inner wall of the sealing ring 3 is 0.064mm. Therefore, L2-L1=0.039mm. The center-to-center distance L3 between the two arc segments 2022 is 4.25mm. The dimension L4 of the straight segment 2021 along the length of the cover body 1 is 2.14mm. Therefore, L4 / L3=0.504. The results of the battery cell production line test verification are shown in Table 1.

[0060] Example 2:

[0061] Along the length of the cover body 1, the reserved gap L1 between the arc segment 2022 and the inner wall of the sealing ring 3 is 0.018mm. Along the width of the cover body 1, the reserved gap L2 between the straight segment 2021 and the inner wall of the sealing ring 3 is 0.052mm. Therefore, L2-L1=0.034mm. The center-to-center distance L3 between the two arc segments 2022 is 3.87mm. The dimension L4 of the straight segment 2021 along the length of the cover body 1 is 2.85mm. Therefore, L4 / L3=0.736. The results of the battery cell production line test verification are shown in Table 1.

[0062] Example 3:

[0063] Along the length of the cover body 1, the reserved gap L1 between the arc segment 2022 and the inner wall of the sealing ring 3 is 0.03mm. Along the width of the cover body 1, the reserved gap L2 between the straight segment 2021 and the inner wall of the sealing ring 3 is 0.075mm. Therefore, L2-L1=0.045mm. The center-to-center distance L3 between the two arc segments 2022 is 4.89mm. The dimension L4 of the straight segment 2021 along the length of the cover body 1 is 3.44mm. Therefore, L4 / L3=0.703. The results of testing and verification on the battery cell production line are shown in Table 1.

[0064] Example 4:

[0065] Along the length of the cover body 1, the reserved gap L1 between the arc segment 2022 and the inner wall of the sealing ring 3 is 0.035mm. Along the width of the cover body 1, the reserved gap L2 between the straight segment 2021 and the inner wall of the sealing ring 3 is 0.086mm. Therefore, L2-L1=0.051mm. The center-to-center distance L3 of the two arc segments 2022 is 5.26mm. The dimension L4 of the straight segment 2021 along the length of the cover body 1 is 3.75mm. Therefore, L4 / L3=0.713. The results of the battery cell production line test verification are shown in Table 1.

[0066] Example 5:

[0067] Along the length of the cover body 1, the reserved gap L1 between the arc segment 2022 and the inner wall of the sealing ring 3 is 0.042mm. Along the width of the cover body 1, the reserved gap L2 between the straight segment 2021 and the inner wall of the sealing ring 3 is 0.107mm. Therefore, L2-L1=0.065mm. The center-to-center distance L3 between the two arc segments 2022 is 6.73mm. The dimension L4 of the straight segment 2021 along the length of the cover body 1 is 4.55mm. Therefore, L4 / L3=0.676. The results of the battery cell production line test verification are shown in Table 1.

[0068] Example 6:

[0069] Along the length of the cover body 1, the reserved gap L1 between the arc segment 2022 and the inner wall of the sealing ring 3 is 0.067mm. Along the width of the cover body 1, the reserved gap L2 between the straight segment 2021 and the inner wall of the sealing ring 3 is 0.139mm. Therefore, L2-L1=0.072mm. The center-to-center distance L3 between the two arc segments 2022 is 7.12mm. The dimension L4 of the straight segment 2021 along the length of the cover body 1 is 5mm. Therefore, L4 / L3=0.702. The results of testing and verification on the battery cell production line are shown in Table 1.

[0070] Example 7:

[0071] Along the length of the cover body 1, the reserved gap L1 between the arc segment 2022 and the inner wall of the sealing ring 3 is 0.058mm. Along the width of the cover body 1, the reserved gap L2 between the straight segment 2021 and the inner wall of the sealing ring 3 is 0.136mm. Therefore, L2-L1=0.078mm. The center-to-center distance L3 between the two arc segments 2022 is 7.94mm. The dimension L4 of the straight segment 2021 along the length of the cover body 1 is 3.85mm. Therefore, L4 / L3=0.485. The results of testing and verification on the battery cell production line are shown in Table 1.

[0072] Example 8:

[0073] Along the length of the cover body 1, the reserved gap L1 between the arc segment 2022 and the inner wall of the sealing ring 3 is 0.074mm. Along the width of the cover body 1, the reserved gap L2 between the straight segment 2021 and the inner wall of the sealing ring 3 is 0.159mm. Therefore, L2-L1=0.085mm. The center-to-center distance L3 between the two arc segments 2022 is 8.48mm. The dimension L4 of the straight segment 2021 along the length of the cover body 1 is 5.25mm. Therefore, L4 / L3=0.619. The results of the battery cell production line test verification are shown in Table 1.

[0074] Example 9:

[0075] Along the length of the cover body 1, the reserved gap L1 between the arc segment 2022 and the inner wall of the sealing ring 3 is 0.088mm. Along the width of the cover body 1, the reserved gap L2 between the straight segment 2021 and the inner wall of the sealing ring 3 is 0.177mm. Therefore, L2-L1=0.089mm. The center-to-center distance L3 between the two arc segments 2022 is 8.55mm. The dimension L4 of the straight segment 2021 along the length of the cover body 1 is 6.05mm. Therefore, L4 / L3=0.708. The results of the battery cell production line test verification are shown in Table 1.

[0076] Example 10:

[0077] Along the length of the cover body 1, the reserved gap L1 between the arc segment 2022 and the inner wall of the sealing ring 3 is 0.092mm. Along the width of the cover body 1, the reserved gap L2 between the straight segment 2021 and the inner wall of the sealing ring 3 is 0.186mm. Therefore, L2-L1=0.094mm. The center-to-center distance L3 between the two arc segments 2022 is 9.36mm. The dimension L4 of the straight segment 2021 along the length of the cover body 1 is 6.75mm. Therefore, L4 / L3=0.721. The results of the battery cell production line test verification are shown in Table 1.

[0078] Comparative Example 1:

[0079] Along the length of the cover body 1, the clearance L1 between the arc segment 2022 and the inner wall of the sealing ring 3 is 0.005mm, less than 0.01mm. Along the width of the cover body 1, the clearance L2 between the straight segment 2021 and the inner wall of the sealing ring 3 is 0.087mm, where L2 - L1 = 0.082mm. The center-to-center distance L3 between the two arc segments 2022 is 3.55mm, and the dimension L4 of the straight segment 2021 along the length of the cover body 1 is 1.85mm, where L4 / L3 = 0.521. The results of testing and verification on the battery cell production line are shown in Table 1.

[0080] Comparative Example 2:

[0081] Along the length of the cover body 1, the clearance L1 between the arc segment 2022 and the inner wall of the sealing ring 3 is 0.007mm, less than 0.01mm. Along the width of the cover body 1, the clearance L2 between the straight segment 2021 and the inner wall of the sealing ring 3 is 0.045mm, where L2 - L1 = 0.038mm. The center-to-center distance L3 between the two arc segments 2022 is 4.47mm, and the dimension L4 of the straight segment 2021 along the length of the cover body 1 is 2.95mm, where L4 / L3 = 0.66. The results of testing and verification on the battery cell production line are shown in Table 1.

[0082] Comparative Example 3:

[0083] Along the length of the cover body 1, the clearance L1 between the arc segment 2022 and the inner wall of the sealing ring 3 is 0.143mm, which is greater than 0.1mm. Along the width of the cover body 1, the clearance L2 between the straight segment 2021 and the inner wall of the sealing ring 3 is 0.185mm, where L2 - L1 = 0.042mm. The center-to-center distance L3 between the two arc segments 2022 is 5.82mm, and the dimension L4 of the straight segment 2021 along the length of the cover body 1 is 4.5mm, where L4 / L3 = 0.773. The results of testing and verification on the battery cell production line are shown in Table 1.

[0084] Comparative Example 4:

[0085] Along the length of the cover body 1, the reserved gap L1 between the arc segment 2022 and the inner wall of the sealing ring 3 is 0.157mm, which is greater than 0.1mm. Along the width of the cover body 1, the reserved gap L2 between the straight segment 2021 and the inner wall of the sealing ring 3 is 0.191mm, so L2 - L1 = 0.034mm. The center-to-center distance L3 between the two arc segments 2022 is 6.48mm, and the dimension L4 of the straight segment 2021 along the length of the cover body 1 is 4.35mm, so L4 / L3 = 0.671. The results of testing and verification on the battery cell production line are shown in Table 1.

[0086] Comparative Example 5:

[0087] Along the length of the cover body 1, the reserved gap L1 between the arc segment 2022 and the inner wall of the sealing ring 3 is 0.015mm. Along the width of the cover body 1, the reserved gap L2 between the straight segment 2021 and the inner wall of the sealing ring 3 is 0.035mm, less than 0.04mm. Therefore, L2 - L1 = 0.02mm. The center-to-center distance L3 between the two arc segments 2022 is 9.75mm, and the dimension L4 of the straight segment 2021 along the length of the cover body 1 is 6.45mm. Therefore, L4 / L3 = 0.662. The results of testing and verification on the battery cell production line are shown in Table 1.

[0088] Comparative Example 6:

[0089] Along the length of the cover body 1, the reserved gap L1 between the arc segment 2022 and the inner wall of the sealing ring 3 is 0.021mm. Along the width of the cover body 1, the reserved gap L2 between the straight segment 2021 and the inner wall of the sealing ring 3 is 0.027mm, less than 0.04mm. Therefore, L2 - L1 = 0.006mm. The center-to-center distance L3 between the two arc segments 2022 is 10.5mm, and the dimension L4 of the straight segment 2021 along the length of the cover body 1 is 7.55mm. Therefore, L4 / L3 = 0.719. The results of testing and verification on the battery cell production line are shown in Table 1.

[0090] Comparative Example 7:

[0091] Along the length of the cover body 1, the reserved gap L1 between the arc segment 2022 and the inner wall of the sealing ring 3 is 0.075mm. Along the width of the cover body 1, the reserved gap L2 between the straight segment 2021 and the inner wall of the sealing ring 3 is 0.214mm, which is greater than 0.2mm. Therefore, L2-L1=0.139mm. The center-to-center distance L3 between the two arc segments 2022 is 10.85mm, and the dimension L4 of the straight segment 2021 along the length of the cover body 1 is 7.3mm. Therefore, L4 / L3=0.673. The results of testing and verification on the battery cell production line are shown in Table 1.

[0092] Comparative Example 8:

[0093] Along the length of the cover body 1, the reserved gap L1 between the arc segment 2022 and the inner wall of the sealing ring 3 is 0.043mm. Along the width of the cover body 1, the reserved gap L2 between the straight segment 2021 and the inner wall of the sealing ring 3 is 0.258mm, which is greater than 0.2mm. Therefore, L2-L1=0.215mm. The center-to-center distance L3 of the two arc segments 2022 is 9.25mm, and the dimension L4 of the straight segment 2021 along the length of the cover body 1 is 6.25mm. Therefore, L4 / L3=0.676. The results of testing and verification on the battery cell production line are shown in Table 1.

[0094] Comparative Example 9:

[0095] Along the length of the cover body 1, the reserved gap L1 between the arc segment 2022 and the inner wall of the sealing ring 3 is 0.043mm. Along the width of the cover body 1, the reserved gap L2 between the straight segment 2021 and the inner wall of the sealing ring 3 is 0.105mm, so L2 - L1 = 0.062mm. The center-to-center distance L3 between the two arc segments 2022 is 8.84mm, and the dimension L4 of the straight segment 2021 along the length of the cover body 1 is 1.55mm. Therefore, L4 / L3 = 0.175, which is less than 0.2. The results of testing and verification on the battery cell production line are shown in Table 1.

[0096] Comparative Example 10:

[0097] Along the length of the cover body 1, the reserved gap L1 between the arc segment 2022 and the inner wall of the sealing ring 3 is 0.066mm. Along the width of the cover body 1, the reserved gap L2 between the straight segment 2021 and the inner wall of the sealing ring 3 is 0.122mm, so L2 - L1 = 0.056mm. The center-to-center distance L3 between the two arc segments 2022 is 7.63mm, and the dimension L4 of the straight segment 2021 along the length of the cover body 1 is 1.25mm. Therefore, L4 / L3 = 0.164, which is less than 0.2. The results of testing and verification on the battery cell production line are shown in Table 1.

[0098] Comparative Example 11:

[0099] Along the length of the cover body 1, the reserved gap L1 between the arc segment 2022 and the inner wall of the sealing ring 3 is 0.052mm. Along the width of the cover body 1, the reserved gap L2 between the straight segment 2021 and the inner wall of the sealing ring 3 is 0.146mm, so L2 - L1 = 0.094mm. The center-to-center distance L3 between the two arc segments 2022 is 5.45mm, and the dimension L4 of the straight segment 2021 along the length of the cover body 1 is 4.65mm. Therefore, L4 / L3 = 0.853, which is greater than 0.8. The results of testing and verification on the battery cell production line are shown in Table 1.

[0100] Comparative Example 12:

[0101] Along the length of the cover body 1, the reserved gap L1 between the arc segment 2022 and the inner wall of the sealing ring 3 is 0.071mm. Along the width of the cover body 1, the reserved gap L2 between the straight segment 2021 and the inner wall of the sealing ring 3 is 0.163mm, so L2 - L1 = 0.092mm. The center-to-center distance L3 between the two arc segments 2022 is 4.66mm, and the dimension L4 of the straight segment 2021 along the length of the cover body 1 is 3.95mm. Therefore, L4 / L3 = 0.848, which is greater than 0.8. The results of testing and verification on the battery cell production line are shown in Table 1.

[0102] Table 1: Test results

[0103]

[0104] As can be seen from Table 1, in Examples 1 to 10, 0.01mm≤L1≤0.1mm, 0.04mm≤L2≤0.2mm, 0.03mm≤L2-L1≤0.1mm, and 0.2≤L4 / L3≤0.8 are satisfied. Therefore, the reserved gap between the sealing ring 3 and the terminal 2 is appropriate. During riveting, the expansion of the straight section 2021 of the second terminal 2 does not affect the normal sealing of the sealing ring 3, and the airtightness requirements are met. The cover body 1 does not deform.

[0105] In Comparative Examples 1 and 2, L1 is lower than the lower limit of the embodiment of the present invention, the sealing ring 3 is easily skewed during assembly, and the airtightness requirement cannot be met.

[0106] In Comparative Examples 3 and 4, L1 exceeds the upper limit of the embodiment of the present invention, the gap between the sealing ring 3 and the pole 2 is large, the sealing performance is poor, the assembly and press-fitting are poor, and the airtightness requirements cannot be met.

[0107] In Comparative Examples 5 and 6, L2 is lower than the lower limit of the embodiment of the present invention. During riveting, the amount of expansion of the straight section 2021 is too large, which easily squeezes the sealing ring 3 and causes the cover body 1 to expand and deform.

[0108] In Comparative Examples 7 and 8, L2 exceeds the upper limit of the embodiment of the present invention, the second pole 2 is too concave, and a gap is easily formed between the sealing ring 3 and the second column 202, resulting in poor assembly and press-fitting, and failing to meet the airtightness requirements.

[0109] In Comparative Examples 9 and 10, L4 / L3 is lower than the lower limit value of the embodiment of the present invention, the straight line segment 2021 accounts for too small a proportion, the indentation amount is small, the transition arc segment 2023 is too long, and the transition arc segment 2023 expands a large amount during the riveting process, squeezing the sealing ring 3 and causing the cover body 1 to deform.

[0110] In Comparative Examples 11 and 12, L4 / L3 exceeds the upper limit value of the embodiments of the present invention, the straight line segment 2021 accounts for a small proportion, the indentation is large, the transition arc segment 2023 is too short, and the dimension of the transition arc segment 2023 along the length direction of the cover body 1 is large, resulting in poor assembly and pressing, and cannot meet the airtightness requirements.

[0111] 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.

[0112] In the battery cell provided by the embodiment of the present invention, the second column 202 of the pole 2 has a dumbbell-shaped cross-section. Compared with the traditional circular cross-section, the flow area is larger and has good flow capacity, which is conducive to the use of large-capacity battery cells and fast-charging cells. The reserved gap L1 between the straight section 2021 and the inner wall of the sealing ring 3 and the reserved gap L2 between the arc section 2022 and the inner wall of the sealing ring 3 are controlled within a suitable range. On the basis of ensuring that the arc section 2022 has sufficient riveting pressure, the expansion amount of the straight section 2021 is reduced, the squeezing of the sealing ring 3 is avoided, the sealing effect is improved, and the risk of deformation of the cover body 1 can also be reduced. If L1 is too small, the sealing ring 3 is easy to be skewed during assembly. If L1 is too large, the sealing gap is large and the sealing performance is poor. If L2 is too small, the amount of material expansion of the straight section 2021 during riveting will be too large, which will easily squeeze the sealing ring 3 and cause deformation of the cover body 1. If L2 is too large, the second pole 2 will be too concave, and a gap will easily form between the sealing ring 3 and the second column 202, resulting in poor sealing performance.

[0113] According to another aspect of an embodiment of the present invention, a battery pack is provided, comprising: at least one battery cell.

[0114] Since the battery pack includes battery cells and has the same effect as the battery cells, it will not be described in detail here.

[0115] 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; A pole, inserted into the mounting hole, the pole comprising a first column, a second column and a bottom plate connected in sequence along the thickness direction, the first column extending to the first surface of the cover body, the bottom plate being provided on the second surface of the cover body opposite to the first surface, the projection of the second column along the thickness direction being a dumbbell shape, the dumbbell shape comprising two straight line segments and two arc segments, the two straight line segments being relatively spaced apart along the width direction of the cover body, the two arc segments being relatively spaced apart along the length direction of the cover body, the two arc segments being respectively connected to the two ends of the straight line segments on the same side, and the arc segments being major arcs; a sealing ring, sleeved on the outer peripheral wall of the second column and sandwiched between the second column and the cover body; Along the length direction of the cover body, the reserved gap between the arc segment and the inner wall of the sealing ring is L1, and along the width direction of the cover body, the reserved gap between the straight segment and the inner wall of the sealing ring is L2, satisfying 0.01mm≤L1≤0.1mm, 0.04mm≤L2≤0.2mm.

2. The battery cover assembly according to claim 1, characterized in that: The reserved gap L1 between the arc segment and the inner wall of the sealing ring along the length direction of the cover body and the reserved gap L2 between the straight segment and the inner wall of the sealing ring along the width direction of the cover body meet 0.03mm≤L2-L1≤0.1mm.

3. The battery cover assembly according to claim 2, characterized in that: The two arc segments are connected to the two ends of the straight line segments on the same side through transition arc segments respectively, and the two ends of the transition arc segments are tangent to the corresponding arc segments and the straight line segments respectively.

4. The battery cover assembly according to claim 3, characterized in that: The distance between the centers of the two arc segments is L3, and the dimension of the straight segment along the length direction of the cover plate body is L4, satisfying 0.2≤L4 / L3≤0.

8.

5. The battery cover assembly according to claim 4, characterized in that: The center distance L3 between the two arc segments satisfies 1mm≤L3≤15mm.

6. The battery cell cover assembly according to any one of claims 1 to 5, characterized in that: The sealing ring is arranged with a constant wall thickness along the circumferential direction.

7. The battery cell cover assembly according to any one of claims 1 to 5, characterized in that: The cell cover assembly further includes an upper insulating member and a rivet block. The rivet block is connected to the first column and arranged corresponding to the first surface. The upper insulating member is sandwiched between the rivet block and the cover body.

8. The battery cell cover assembly according to any one of claims 1 to 5, characterized in that: The cell cover assembly further includes a lower insulating member, which is attached to the second surface. The bottom plate is located on a side of the lower insulating member away from the second surface. The sealing ring is further sandwiched between the bottom plate and the lower insulating member.

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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