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; the pole body comprises a main body and a connecting body which are connected with each other, and orthographic projections of the main body and the connecting body along a first direction are runway-shaped; a runway hole is formed in the pole bottom plate, the connector penetrates through the runway hole and is welded with the pole bottom plate, the section of the runway hole comprises two straight line sections and two arc sections, the two straight line sections are oppositely arranged at intervals in the width direction of the cover plate body, and the two arc sections are oppositely arranged at intervals in the length direction of the cover plate body; the size of the arc section in the width direction of the cover plate body is L2, the size of the pole bottom plate in the width direction of the cover plate body is L4, and L2 / L4 is larger than or equal to 0.25 and smaller than or equal to 0.5. The welding quality between the pole body and the pole bottom plate can be improved by controlling the size of the runway hole in the pole bottom plate to be within a proper range.

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 enhance 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 designed with a runway-shaped cross-section and then connected to the terminal base plate.

[0003] However, the pole body with a runway-shaped cross-section structure is affected by its shape, resulting in uneven contact surface and uneven pressure distribution, which makes it difficult to press-fit the pole body. The pole body is difficult to press-fit and weld to the pole base plate, and it is also easy to cause welding defects such as fracture, warping, and swelling in the weak areas of the pole base plate, resulting in poor welding 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 when a pole body with a runway-shaped cross-section structure is press-fitted and welded to a pole base plate, there is difficulty in press-fitting, which easily causes welding defects in the weak area of ​​the pole base plate, resulting in poor welding 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;

[0007] a pole body, inserted into the mounting hole, the pole body comprising a main body and a connector connected to each other, the orthographic projections of the main body and the connector along the first direction both being runway-shaped, and the main body extending to the first surface of the cover body;

[0008] a pole bottom plate, provided on a second surface of the cover body opposite to the first surface, a runway hole being formed on the pole bottom plate, the connector being passed through the runway hole and welded to the pole bottom plate, the runway hole comprising two straight segments and two arc segments in a cross section perpendicular to the first direction, the two straight 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 two ends of the two straight segments on the same side;

[0009] The dimension of the arc segment along the width direction of the cover body is L2, and the dimension of the pole bottom plate along the width direction of the cover body is L4, satisfying 0.25≤L2 / L4≤0.5.

[0010] Beneficial effects: The battery cell cover plate assembly of the present invention has a main body of the pole body adopts a runway-shaped cross-section. Compared with the traditional circular cross-section, the flow area is larger, the flow capacity is improved, and thus the fast charging capability and capacity of the battery cell are improved. By welding the connector to the pole base plate and controlling the size of the runway hole of the pole base plate within an appropriate range, the welding quality of the weak area of ​​the pole base plate can be improved, and the risk of defects such as deformation, swelling, and fracture in the weak area of ​​the pole base plate can be reduced. If L2 / L4 is too small, the size of the connector is too small, which makes it difficult to form the pole body, and the welding area is small, which makes welding more difficult. If L2 / L4 is too large, the width of the weak area is too narrow, which easily leads to deformation and fracture defects in the weak area during welding. In addition, the positive projection of the connector along the first direction is runway-shaped, which has good anti-torsion performance. After welding, it can better withstand vibration or external impact in the battery charge and discharge cycle, reduce the risk of weld cracking, and expand the contact area of ​​the connector, which can reduce local heating caused by uneven current collection.

[0011] In an optional embodiment, the dimension of the straight segment along the length direction of the cover body is L1, and the spacing between the straight segment and the adjacent side wall of the pole bottom plate along the width direction of the cover body is L3, satisfying 0.1≤L1 / L3≤10.

[0012] Beneficial Effect: By further limiting the length of the straight segment and the distance between the straight segment and the pole base plate, welding quality can be further improved. If L1 / L3 is too large, the welding area is too large, causing the pole base plate to deform during welding and the surrounding plastic parts to melt easily. If L1 / L3 is too small, the welding area is too small, making welding more difficult.

[0013] In an optional embodiment, the spacing between the two straight line segments and the side walls of the adjacent pole bottom plates along the width direction of the cover body is equal, satisfying L4=2×L3+L2, 2 / 3≤L2 / L3≤2.

[0014] Beneficial effect: The spacing between the two straight segments and the side wall of the pole bottom plate along the width direction of the cover plate body is set to be the same, that is, the runway hole is set in the middle position of the pole bottom plate, which is conducive to uniform force on all sides of the pole bottom plate, reduces stress concentration, and further reduces the risk of defects such as deformation, swelling, and fracture in the weak area of ​​the pole bottom plate.

[0015] In an optional embodiment, a dimension L1 of the straight line segment along the length direction of the cover plate body satisfies 1mm≤L1≤30mm.

[0016] Beneficial effect: By controlling the size of the straight section along the length direction of the cover body within an appropriate range, press-fitting and welding are facilitated. If L1 is too large, the straight section is too long and easily deformed during welding, and the welding time is too long, which can easily cause thermal melting of the insulating parts around the pole bottom plate. If L1 is too small, the flow area is small and the flow capacity is weak.

[0017] In an optional embodiment, a dimension L2 of the arc segment along the width direction of the cover plate body satisfies 2.5 mm ≤ L2 ≤ 15 mm.

[0018] Beneficial Effect: By controlling the arc segment's width along the cover plate within an appropriate range, welding is facilitated. If L2 is too small, the runway hole is too narrow, making welding difficult, and the flow area is small, resulting in weak flow capacity. Furthermore, the connector must fit within the runway hole, indirectly controlling its width. If the width is too small, it will be difficult to form.

[0019] In an optional embodiment, a distance L3 between the straight segment and adjacent side walls of the pole bottom plate along the width direction of the cover plate body satisfies 1.5 mm ≤ L3 ≤ 10 mm.

[0020] Beneficial effect: The area between the straight section and the adjacent side walls of the pole bottom plate along the width direction of the cover body is a weak area. By controlling the range of the spacing L3, the width of the weak area can be controlled within an appropriate range to avoid the weak area being too narrow, which may cause deformation and fracture during welding. If the weak area is too wide, space and materials will be wasted.

[0021] In an optional embodiment, a dimension L4 of the pole bottom plate along the width direction of the cover plate body satisfies 5.5 mm ≤ L4 ≤ 35 mm.

[0022] Beneficial effect: By controlling the width of the pole base plate within an appropriate range, the welding quality of the weak area can be further improved.

[0023] 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 main body and corresponding to the first surface, and the first insulating member is clamped between the rivet block and the cover body.

[0024] Beneficial Effects: The first insulating member can effectively isolate the pole body from the cover body, preventing risks such as short circuits and leakage in the pole body. The main body is fixed by riveting blocks, which can resist external forces such as vibration and impact, and improve the installation stability of the pole body.

[0025] 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 sleeved on the outer peripheral wall of the main body and clamped between the pole bottom plate and the second insulating member and between the main body and the cover body.

[0026] Beneficial effect: By arranging a sealing ring on the outer peripheral wall of the main body, a sealing effect can be achieved to prevent leakage of electrolyte in the battery cell and prevent external foreign matter from entering the battery cell. In addition, the sealing ring also has good insulation properties.

[0027] In a second aspect, the present invention further provides a battery cell, comprising:

[0028] a housing having an opening at at least one end;

[0029] In the above-mentioned battery cell cover assembly, the cover body is arranged to cover the opening and is connected to the shell.

[0030] Beneficial effects: The battery cell of the present invention has a main body of the pole body adopts a runway-shaped cross-section, which has a larger flow area than the traditional circular cross-section, thereby improving the flow capacity and thus improving the fast charging capability and capacity of the battery cell. By welding the connector to the pole base plate and controlling the size of the runway hole of the pole base plate within an appropriate range, the welding quality of the weak area of ​​the pole base plate can be improved, and the risk of defects such as deformation, swelling, and fracture in the weak area of ​​the pole base plate can be reduced. In addition, the positive projection of the connector along the first direction is runway-shaped, which has good anti-torsion performance. After welding, it can better withstand vibrations or external impacts in the battery charge and discharge cycle, reduce the risk of weld cracking, and expand the contact area of ​​the connector, which can reduce local heating caused by uneven current collection.

[0031] In a third aspect, the present invention further provides a battery pack comprising: at least one of the above-mentioned battery cells.

[0032] Beneficial effects: Since the battery pack includes battery cells, it has the same effects as the battery cells and will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] 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.

[0034] Figure 1 This is a structural schematic diagram of a battery cell cover assembly according to an embodiment of the present invention;

[0035] Figure 2 An exploded view of a battery cell cover assembly according to an embodiment of the present invention;

[0036] Figure 3 This is a bottom view of a battery cell cover assembly according to an embodiment of the present invention;

[0037] Figure 4 This is a schematic diagram of a runway hole of a battery cell cover assembly according to an embodiment of the present invention;

[0038] Figure 5 This is a schematic diagram of a pole body of a battery cell cover assembly according to an embodiment of the present invention.

[0039] Description of reference numerals:

[0040] 1. Cover plate body; 101. Mounting hole; 2. Pole body; 201. Main body; 202. Connector; 3. Pole base plate; 301. Runway hole; 3011. Straight segment; 3012. Arc segment; 4. First insulating member; 5. Riveted block; 6. Sealing ring; 7. Second insulating member. DETAILED DESCRIPTION

[0041] 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.

[0042] The following combination Figures 1 to 5 , describing embodiments of the present invention.

[0043] According to an embodiment of the present invention, on the one hand, Figure 1 and Figure 2As shown, a battery cell cover plate assembly is provided, mainly comprising: a cover plate body 1, a pole body 2, and a pole base plate 3. The cover plate body 1 is provided with a mounting hole 101. The pole body 2 is inserted into the mounting hole 101 and comprises a main body 201 and a connector 202 connected to each other. The orthographic projections of the main body 201 and the connector 202 along a first direction are both runway-shaped, and the main body 201 extends to the first surface of the cover plate body 1. The pole base plate 3 is provided on the second surface of the cover body 1 opposite to the first surface. A runway hole 301 is provided on the pole base plate 3. The connector 202 is passed through the runway hole 301 and welded to the pole base plate 3. The runway hole 301 includes two straight segments 3011 and two arc segments 3012 in a cross section perpendicular to the first direction. The two straight segments 3011 are relatively spaced apart along the width direction of the cover body 1, and the two arc segments 3012 are relatively spaced apart along the length direction of the cover body 1. The two arc segments 3012 are respectively connected to the two ends of the two straight segments 3011 on the same side.

[0044] like Figure 3 and Figure 4 As shown, the dimension of the arc segment 3012 along the width direction of the cover body 1 is L2, and the dimension of the pole bottom plate 3 along the width direction of the cover body 1 is L4, satisfying 0.25≤L2 / L4≤0.5.

[0045] It can be seen that the battery cell cover plate assembly provided by the embodiment of the present invention has a main body 201 of the pole body 2 adopts a runway-shaped cross-section. Compared with the traditional circular cross-section, the flow area is larger, the flow capacity is improved, and thus the fast charging capability and capacity of the battery cell are improved. By welding the connector 202 to the pole base plate 3 and controlling the size of the runway hole 301 of the pole base plate 3 within an appropriate range, the welding quality of the weak area of ​​the pole base plate 3 can be improved, and the risk of defects such as deformation, swelling, and fracture in the weak area of ​​the pole base plate 3 can be reduced. If L2 / L4 is too small, the size of the connector 202 is too small, resulting in the pole body 2 being difficult to form, and the welding area is small, which makes welding more difficult. If L2 / L4 is too large, the width of the weak area is too narrow, which easily leads to deformation and fracture defects in the weak area during welding. In addition, the positive projection of the connector 202 along the first direction is runway-shaped, which has good anti-torsion performance. After welding, it can better withstand vibration or external impact during the battery charge and discharge cycle, reduce the risk of weld cracking, and expand the contact area of ​​the connector 202, which can reduce local heating caused by uneven current collection.

[0046] Specifically, the connector 202 is inserted into the runway hole 301 and then welded to the seam by press fitting. Figure 5As shown, the orthographic projection of the connector 202 in the first direction falls within the orthographic projection of the main body 201 in the first direction, that is, the size of the connector 202 is smaller than that of the main body 201, which is convenient for welding. The connector 202 is fixed to one end of the main body 201 close to the pole bottom plate 3. The first direction is also the axial direction of the pole body 2, that is, the thickness direction of the cover body 1. Figure 1 As shown by the arrow H in FIG. The length direction of the cover body 1 is as shown in FIG. 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 .

[0047] It should be noted that the cell cover assembly of this embodiment is applied to blade batteries. 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 be increased, 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 this embodiment, the main body 201 of the pole body 2 is set to a runway 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.

[0048] It should be noted that in this embodiment, the size of the main body 201 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 main body 201 is also increased as much as possible to increase the flow area of ​​the main body 201, thereby having good flow capacity.

[0049] In one embodiment, Figure 3 and Figure 4 As shown, the dimension of the straight segment 3011 along the length of the cover body 1 is L1, and the spacing between the straight segment 3011 and the adjacent sidewalls of the pole base plate 3 along the width of the cover body 1 is L3, satisfying 0.1≤L1 / L3≤10. By further limiting the length of the straight segment 3011 and the spacing between the straight segment 3011 and the pole base plate 3, welding quality can be further improved. If L1 / L3 is too large, the weld area is too large, causing deformation of the pole base plate 3 during welding and the surrounding plastic parts to melt easily. If L1 / L3 is too small, the weld area is too small, making welding more difficult.

[0050] Specifically, the straight segment 3011 extends along the length of the cover body 1, so L1 is the length of the straight segment 3011. The arc segment 3012 can be a semicircle, in which case L2 is the diameter of the arc segment 3012. The spacing between the straight segment 3011 and the adjacent sidewalls of the pole base plate 3 along the width of the cover body 1 is typically smaller than the spacing between the arc segment 3012 and the adjacent sidewalls of the pole base plate 3 along the length of the cover body 1. Therefore, the area between the straight segment 3011 and the adjacent sidewalls of the pole base plate 3 along the width of the cover body 1 is a weak zone, and L3 is the minimum width of the weak zone.

[0051] In one embodiment, Figure 3 As shown, the spacing between the two straight segments 3011 and the sidewalls of the adjacent pole base plates 3 along the width of the cover body 1 is equal, meaning that the runway hole 301 is located at the center of the pole base plate 3, satisfying L4 = 2 × L3 + L2, and 2 / 3 ≤ L2 / L3 ≤ 2. Setting the spacing between the two straight segments 3011 and the sidewalls of the pole base plate 3 along the width of the cover body 1 equal, meaning that the runway hole 301 is located in the center of the pole base plate 3, facilitates uniform stress distribution around the pole base plate 3, reduces stress concentration, and further reduces the risk of defects such as deformation, swelling, and fracture in weak areas of the pole base plate 3.

[0052] In one embodiment, Figure 3 As shown, the dimension L1 of the straight segment 3011 along the length of the cover body 1 satisfies 1mm≤L1≤30mm. By controlling the dimension of the straight segment 3011 along the length of the cover body 1 within an appropriate range, press-fit welding is facilitated. If L1 is too large, the straight segment 3011 will be too long, easily deforming during welding, and the welding time will be too long, which can easily cause thermal melting of the insulating components around the pole base plate 3. If L1 is too small, the flow area will be small and the flow capacity will be weak.

[0053] In one embodiment, Figure 3 As shown, the dimension L2 of the arc segment 3012 along the width of the cover body 1 satisfies 2.5mm≤L2≤15mm. By controlling the dimension of the arc segment 3012 along the width of the cover body 1 within an appropriate range, welding is facilitated. If L2 is too small, the runway hole 301 will be too narrow, making welding difficult, and the flow area will be small, resulting in weak flow capacity. Furthermore, the connector 202 must fit within the runway hole 301, indirectly controlling its width. If the width of the connector 202 is too small, it will be difficult to form.

[0054] In one embodiment, Figure 3As shown, the spacing L3 between the straight segment 3011 and the adjacent sidewalls of the pole base plate 3 along the width direction of the cover body 1 satisfies 1.5 mm ≤ L3 ≤ 10 mm. By controlling the range of spacing L3, the width of the weak zone can be controlled within an appropriate range, avoiding a weak zone that is too narrow, which could cause deformation and fracture during welding. If the weak zone is too wide, it would waste space and material.

[0055] In one embodiment, Figure 3 As shown, the dimension L4 of the pole bottom plate 3 along the width direction of the cover plate body 1 satisfies 5.5mm≤L4≤35mm. By controlling the width dimension of the pole bottom plate 3 within an appropriate range, the welding quality of the weak area can be further improved.

[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 main body 201 and is arranged corresponding to the first surface. The first insulating member 4 is clamped between the rivet block 5 and the cover body 1. The first insulating member 4 can effectively isolate the pole body 2 and the cover body 1, avoiding risks such as short circuit and leakage in the pole body 2. The main body 201 is fixed by the rivet block 5, which can resist external forces such as vibration and impact, and improve the installation stability of the pole body 2. The first insulating member 4 and the rivet block 5 can protrude from the first surface, and correspondingly, the main body 201 can extend out of the first surface of the cover body 1.

[0057] It should be noted that when the cell cover assembly is installed with the cell housing, the first surface of the cover body 1 is located on the outside, and the second surface is located on the inside. In addition, the pole base plate 3 is located on the inside of the cover body 1, and the main body 201 needs to extend and partially expose the outside of the cover body 1.

[0058] In one embodiment, Figure 1 and Figure 2 As shown, the cell cover assembly further 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 bottom plate 3 is disposed on a 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 main body 201 and is sandwiched between the pole bottom plate 3 and the second insulating member 7, as well as between the main body 201 and the cover body 1. The sealing ring 6 sleeved on the outer peripheral wall of the main body 201 provides a seal to prevent leakage of the electrolyte in the cell and prevent foreign matter from entering the cell. Furthermore, the sealing ring 6 provides excellent insulation.

[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 dimension L1 of the straight segment 3011 of the track hole 301 along the length of the cover body 1 is 6 mm. The dimension L2 of the arc segment 3012 of the track hole 301 along the width of the cover body 1 is 2.8 mm. The spacing L3 between the straight segment 3011 and the adjacent sidewall of the terminal base plate 3 along the width of the cover body 1 is 1.5 mm. The dimension L4 of the terminal base plate 3 along the width of the cover body 1 is 5.8 mm. L1 / L3 = 4, L2 / L4 = 0.48. The results of testing and verification on the battery cell production line are shown in Table 1.

[0063] Example 2:

[0064] The dimension L1 of the straight segment 3011 of the track hole 301 along the length of the cover body 1 is 6.8 mm. The dimension L2 of the arc segment 3012 of the track hole 301 along the width of the cover body 1 is 2.5 mm. The spacing L3 between the straight segment 3011 and the adjacent sidewall of the terminal base plate 3 along the width of the cover body 1 is 1.8 mm. The dimension L4 of the terminal base plate 3 along the width of the cover body 1 is 6.1 mm. L1 / L3 = 3.78, L2 / L4 = 0.41. The results of testing and verification on the battery cell production line are shown in Table 1.

[0065] Example 3:

[0066] The dimension L1 of the straight segment 3011 of the track hole 301 along the length of the cover body 1 is 5 mm. The dimension L2 of the arc segment 3012 of the track hole 301 along the width of the cover body 1 is 2.8 mm. The spacing L3 between the straight segment 3011 and the adjacent sidewall of the terminal base plate 3 along the width of the cover body 1 is 2.7 mm. The dimension L4 of the terminal base plate 3 along the width of the cover body 1 is 8.2 mm. L1 / L3 = 1.85, L2 / L4 = 0.34. The results of testing and verification on the battery cell production line are shown in Table 1.

[0067] Example 4:

[0068] The dimension L1 of the straight segment 3011 of the track hole 301 along the length of the cover body 1 is 7 mm. The dimension L2 of the arc segment 3012 of the track hole 301 along the width of the cover body 1 is 4.1 mm. The spacing L3 between the straight segment 3011 and the adjacent sidewall of the terminal base plate 3 along the width of the cover body 1 is 2.2 mm. The dimension L4 of the terminal base plate 3 along the width of the cover body 1 is 8.5 mm. L1 / L3 = 3.18, L2 / L4 = 0.48. The results of testing and verification on the battery cell production line are shown in Table 1.

[0069] Example 5:

[0070] The dimension L1 of the straight segment 3011 of the track hole 301 along the length of the cover body 1 is 5 mm. The dimension L2 of the arc segment 3012 of the track hole 301 along the width of the cover body 1 is 3 mm. The spacing L3 between the straight segment 3011 and the adjacent sidewall of the terminal base plate 3 along the width of the cover body 1 is 2 mm. The dimension L4 of the terminal base plate 3 along the width of the cover body 1 is 7 mm. L1 / L3 = 2.5, L2 / L4 = 0.43. The results of testing and verification on the battery cell production line are shown in Table 1.

[0071] Example 6:

[0072] The dimension L1 of the straight segment 3011 of the track hole 301 along the length of the cover body 1 is 10 mm. The dimension L2 of the arc segment 3012 of the track hole 301 along the width of the cover body 1 is 5 mm. The spacing L3 between the straight segment 3011 and the adjacent sidewall of the terminal base plate 3 along the width of the cover body 1 is 2.5 mm. Therefore, the dimension L4 of the terminal base plate 3 along the width of the cover body 1 is 10 mm. L1 / L3 = 4, and L2 / L4 = 0.5. The results of testing and verification on the battery cell production line are shown in Table 1.

[0073] Example 7:

[0074] The dimension L1 of the straight segment 3011 of the track hole 301 along the length of the cover body 1 is 8.5 mm. The dimension L2 of the arc segment 3012 of the track hole 301 along the width of the cover body 1 is 4.3 mm. The spacing L3 between the straight segment 3011 and the adjacent sidewall of the terminal base plate 3 along the width of the cover body 1 is 3 mm. The dimension L4 of the terminal base plate 3 along the width of the cover body 1 is 10.3 mm. L1 / L3 = 2.83, L2 / L4 = 0.42. The results of testing and verification on the battery cell production line are shown in Table 1.

[0075] Example 8:

[0076] The dimension L1 of the straight segment 3011 of the track hole 301 along the length of the cover body 1 is 25 mm. The dimension L2 of the arc segment 3012 of the track hole 301 along the width of the cover body 1 is 5.2 mm. The spacing between the straight segment 3011 and the adjacent sidewall of the terminal base plate 3 along the width of the cover body 1 is 3.8 mm. Therefore, the dimension L4 of the terminal base plate 3 along the width of the cover body 1 is 12.8 mm. L1 / L3 = 6.58, L2 / L4 = 0.41. The results of testing and verification on the battery cell production line are shown in Table 1.

[0077] Example 9:

[0078] The dimension L1 of the straight segment 3011 of the track hole 301 along the length of the cover body 1 is 30 mm. The dimension L2 of the arc segment 3012 of the track hole 301 along the width of the cover body 1 is 2.6 mm. The spacing between the straight segment 3011 and the adjacent sidewall of the terminal base plate 3 along the width of the cover body 1 is 3.2 mm. Therefore, the dimension L4 of the terminal base plate 3 along the width of the cover body 1 is 9 mm. L1 / L3 = 9.38, and L2 / L4 = 0.29. The results of testing and verification on the battery cell production line are shown in Table 1.

[0079] Example 10:

[0080] The dimension L1 of the straight segment 3011 of the track hole 301 along the length of the cover body 1 is 18 mm. The dimension L2 of the arc segment 3012 of the track hole 301 along the width of the cover body 1 is 7 mm. The spacing L3 between the straight segment 3011 and the adjacent sidewall of the terminal base plate 3 along the width of the cover body 1 is 4 mm. The dimension L4 of the terminal base plate 3 along the width of the cover body 1 is 15 mm. L1 / L3 = 4.5, L2 / L4 = 0.47. The results of testing and verification on the battery cell production line are shown in Table 1.

[0081] Comparative Example 1:

[0082] The dimension L1 of the straight segment 3011 of the track hole 301 along the length of the cover body 1 is 8.5 mm. The dimension L2 of the arc segment 3012 of the track hole 301 along the width of the cover body 1 is 3.2 mm. The spacing L3 between the straight segment 3011 and the adjacent sidewall of the terminal base plate 3 along the width of the cover body 1 is 1 mm, less than 1.5 mm. The dimension L4 of the terminal base plate 3 along the width of the cover body 1 is 5.2 mm. L1 / L3 = 8.5, and L2 / L4 = 0.62, both greater than 0.5. The results of testing and verification on the battery cell production line are shown in Table 1.

[0083] Comparative Example 2:

[0084] The dimension L1 of the straight segment 3011 of the track hole 301 along the length of the cover body 1 is 5 mm. The dimension L2 of the arc segment 3012 of the track hole 301 along the width of the cover body 1 is 4 mm. The spacing L3 between the straight segment 3011 and the adjacent sidewall of the terminal base plate 3 along the width of the cover body 1 is 0.8 mm, less than 1.5 mm. The dimension L4 of the terminal base plate 3 along the width of the cover body 1 is 5.6 mm. L1 / L3 = 6.25, and L2 / L4 = 0.71, both greater than 0.5. The results of testing and verification on the battery cell production line are shown in Table 1.

[0085] Comparative Example 3:

[0086] The dimension L1 of the straight segment 3011 of the track hole 301 along the length of the cover body 1 is 24 mm. The dimension L2 of the arc segment 3012 of the track hole 301 along the width of the cover body 1 is 2 mm, less than 2.5 mm. The spacing L3 between the straight segment 3011 and the adjacent sidewall of the terminal base plate 3 along the width of the cover body 1 is 4 mm. The dimension L4 of the terminal base plate 3 along the width of the cover body 1 is 10 mm. L1 / L3 = 6, and L2 / L4 = 0.2, less than 0.25. The results of testing and verification on the battery cell production line are shown in Table 1.

[0087] Comparative Example 4:

[0088] The dimension L1 of the straight segment 3011 of the track hole 301 along the length of the cover body 1 is 22.5 mm. The dimension L2 of the arc segment 3012 of the track hole 301 along the width of the cover body 1 is 1.5 mm, less than 2.5 mm. The spacing L3 between the straight segment 3011 and the adjacent sidewall of the terminal base plate 3 along the width of the cover body 1 is 3.8 mm. The dimension L4 of the terminal base plate 3 along the width of the cover body 1 is 9.1 mm. L1 / L3 = 5.92, L2 / L4 = 0.16, less than 0.25. The results of testing and verification on the battery cell production line are shown in Table 1.

[0089] Comparative Example 5:

[0090] The dimension L1 of the straight segment 3011 of the track hole 301 along the length of the cover body 1 is 52 mm, greater than 30 mm. The dimension L2 of the arc segment 3012 of the track hole 301 along the width of the cover body 1 is 7.3 mm. The spacing L3 between the straight segment 3011 and the adjacent sidewall of the terminal base plate 3 along the width of the cover body 1 is 4.5 mm. The dimension L4 of the terminal base plate 3 along the width of the cover body 1 is 16.3 mm. L1 / L3 = 11.56, greater than 10, and L2 / L4 = 0.45. The results of testing and verification on the battery cell production line are shown in Table 1.

[0091] Comparative Example 6:

[0092] The dimension L1 of the straight segment 3011 of the track hole 301 along the length of the cover body 1 is 44 mm, greater than 30 mm. The dimension L2 of the arc segment 3012 of the track hole 301 along the width of the cover body 1 is 2.5 mm. The spacing L3 between the straight segment 3011 and the adjacent sidewall of the terminal base plate 3 along the width of the cover body 1 is 3.1 mm. The dimension L4 of the terminal base plate 3 along the width of the cover body 1 is 8.7 mm. L1 / L3 = 14.19, greater than 10, and L2 / L4 = 0.29. The results of testing and verification on the battery cell production line are shown in Table 1.

[0093] Table 1: Test results

[0094]

[0095] As can be seen from Table 1, in Examples 1 to 10, 0.1≤L1 / L3≤10, 0.25≤L2 / L4≤0.5, 1mm≤L1≤30mm, 2.5mm≤L2≤15mm, 1.5mm≤L3≤10mm, and 5.5mm≤L4≤35mm are satisfied. The welding quality of the pole base plate 3 and the pole body 2 is good.

[0096] In Comparative Examples 1 and 2, L3 is less than 1.5 mm, L2 / L4 is greater than 0.5, and the width of the weak zone is too narrow, resulting in deformation and fracture defects in the weak zone during welding.

[0097] In Comparative Examples 3 and 4, L2 is less than 2.5 mm, and L2 / L4 is less than 0.25. The connector 202 of the pole body 2 is too small, making it difficult to form. In addition, the welding area is small, making welding more difficult.

[0098] In Comparative Examples 5 and 6, L1 is greater than 30 mm, L1 / L3 is greater than 10, the connector 202 of the pole body 2 is too large, and the welding area is too large, causing the pole base plate 3 to deform during welding and the surrounding plastic parts to melt.

[0099] 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.

[0100] In the battery cell provided by the embodiment of the present invention, the main body 201 of the pole body 2 adopts a runway-shaped cross-section. Compared with the traditional circular cross-section, the flow area is larger, the flow capacity is improved, and thus the fast charging capability and capacity of the battery cell are improved. By welding the connector 202 to the pole base plate 3 and controlling the size of the runway hole 301 of the pole base plate 3 within an appropriate range, the welding quality of the weak area of ​​the pole base plate 3 can be improved, and the risk of defects such as deformation, swelling, and fracture in the weak area of ​​the pole base plate 3 can be reduced. In addition, the positive projection of the connector 202 along the first direction is runway-shaped, which has good anti-torsion performance. After welding, it can better withstand vibrations or external impacts in the battery charge and discharge cycle, reduce the risk of weld cracking, and expand the contact area of ​​the connector 202, which can reduce local heating caused by uneven current collection.

[0101] According to another aspect of an embodiment of the present invention, a battery pack is provided, comprising: at least one battery cell.

[0102] Since the battery pack includes battery cells and has the same effect as the battery cells, it will not be described in detail here.

[0103] 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; a pole body, inserted into the mounting hole, the pole body comprising a main body and a connector connected to each other, the orthographic projections of the main body and the connector along the first direction both being runway-shaped, and the main body extending to the first surface of the cover body; a pole bottom plate, provided on a second surface of the cover body opposite to the first surface, a runway hole being formed on the pole bottom plate, the connector being passed through the runway hole and welded to the pole bottom plate, the runway hole comprising two straight segments and two arc segments in a cross section perpendicular to the first direction, the two straight segments being spaced apart relative to each other along the width direction of the cover body, the two arc segments being spaced apart relative to each other along the length direction of the cover body, the two arc segments being respectively connected to two ends of the two straight segments on the same side; The dimension of the arc segment along the width direction of the cover body is L2, and the dimension of the pole bottom plate along the width direction of the cover body is L4, satisfying 0.25≤L2 / L4≤0.

5.

2. The battery cover assembly according to claim 1, characterized in that: The dimension of the straight segment along the length direction of the cover body is L1, and the distance between the straight segment and the adjacent side wall of the pole bottom plate along the width direction of the cover body is L3, satisfying 0.1≤L1 / L3≤10.

3. The battery cover assembly according to claim 2, characterized in that: The spacing between the two straight segments and the side walls of the adjacent pole bottom plates along the width direction of the cover plate body is equal, satisfying L4=2×L3+L2, 2 / 3≤L2 / L3≤2.

4. The battery cover assembly according to claim 3, characterized in that: A dimension L1 of the straight line segment along the length direction of the cover plate body satisfies 1mm≤L1≤30mm.

5. The battery cover assembly according to claim 3, characterized in that: The dimension L2 of the arc segment along the width direction of the cover body satisfies 2.5mm≤L2≤15mm; And / or, a distance L3 between the straight segment and adjacent side walls of the pole bottom plate along the width direction of the cover plate body satisfies 1.5 mm ≤ L3 ≤ 10 mm.

6. The battery cover assembly according to claim 3, characterized in that: A dimension L4 of the pole bottom plate along the width direction of the cover plate body satisfies 5.5 mm ≤ L4 ≤ 35 mm.

7. The battery cell cover assembly according to any one of claims 1 to 6, characterized in that: The cell cover assembly further includes a first insulating member and a rivet block. The rivet block is connected to the main body and corresponding to the first surface. The first insulating member is sandwiched between the rivet block and the cover body.

8. The battery cover assembly according to claim 7, 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 main body and clamped between the pole bottom plate and the second insulating member and between the main body and the cover body.

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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