Battery cell cover plate assembly, battery cell, and battery pack

Abstract

The application relates to the technical field of batteries and discloses a battery cell cover plate assembly, a battery cell and a battery pack, wherein the battery cell cover plate assembly comprises a cover plate body, a pole body and a pole bottom plate; the pole body comprises a main body and a connecting body connected with each other, and the main body and the connecting body are both runway-shaped in orthographic projection along a first direction; a runway hole is formed in the pole bottom plate, the connecting body is arranged in the runway hole, and the connecting body is welded with the pole bottom plate; the cross section of the runway hole comprises two straight line segments and two circular arc segments, the two straight line segments are oppositely arranged along the width direction of the cover plate body, and the two circular arc segments are oppositely arranged along the length direction of the cover plate body; the size of the circular arc segment along the width direction of the cover plate body is L2, the size of the pole bottom plate along the width direction of the cover plate body is L4, and 0.25 <= L2 / L4 <= 0.5 is met. By controlling the size of the runway hole on the pole bottom plate within a proper range, the welding quality between the pole body and the pole bottom plate can be improved.

Description

Technical Field

[0001] This invention relates to the field of battery technology, specifically to cell cover assemblies, cells, and battery packs. Background Technology

[0002] With the continuous development of technology, users have increasingly higher requirements for new energy batteries. In order to improve the fast charging capability of the battery cells, it is necessary to improve the current carrying capacity of the terminals. On thin battery cells, in order to ensure the current carrying capacity of the terminals, the terminal body can be made into a racetrack-shaped cross-section structure and then connected to the terminal base plate.

[0003] However, due to its shape, the pole body of the racetrack-shaped cross section has 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 for the weak areas of the pole base plate to have welding defects such as breakage, warping, and material expansion, resulting in poor welding quality. Summary of the Invention

[0004] In view of this, the present invention provides a cell cover plate assembly, a cell, and a battery pack to solve the problem that when pressing and welding the pole body and the pole base plate of the racetrack-shaped cross-section structure, there are difficulties in pressing and welding, which easily leads to poor welding defects in the weak areas 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 plate body is provided with mounting holes;

[0007] The pole body is inserted into the mounting hole. The pole body includes a main body and a connecting body connected to each other. The orthographic projection of the main body and the connecting body along the first direction is racetrack-shaped. The main body extends to the first surface of the cover plate body.

[0008] A pole base plate is disposed on the second surface of the cover plate body opposite to the first surface. A racetrack hole is formed on the pole base plate. The connector passes through the racetrack hole and is welded to the pole base plate. The cross section of the racetrack hole perpendicular to the first direction includes two straight segments and two arc segments. The two straight segments are arranged relatively spaced along the width direction of the cover plate body, and the two arc segments are arranged relatively spaced along the length direction of the cover plate body. The two arc segments are respectively connected to the two ends of the two straight segments on the same side.

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

[0010] Beneficial Effects: The cell cover assembly of this invention features a racetrack-shaped cross-section for the main body of the terminal post. Compared to the traditional circular cross-section, this provides a larger current-carrying area, enhancing current-carrying capacity and thus improving the cell's fast-charging capability and capacity. By welding the connector to the terminal post base plate and controlling the size of the racetrack holes in the base plate within a suitable range, the welding quality of the weak areas of the terminal post base plate can be improved, reducing the risk of deformation, material expansion, and breakage in these areas. If L2 / L4 is too small, the connector will be too small, making it difficult to form the terminal post and resulting in a smaller welding area and greater welding difficulty. If L2 / L4 is too large, the width of the weak area will be too narrow, easily leading to deformation and breakage defects during welding. Furthermore, the racetrack shape of the connector's orthographic projection along the first direction provides excellent torsional resistance, allowing it to better withstand vibrations or external impacts during battery charge-discharge cycles after welding, reducing the risk of weld cracking. It also expands the contact area of ​​the connector, reducing localized heating caused by uneven current distribution.

[0011] In one optional embodiment, the straight segment has a dimension of L1 along the length direction of the cover plate body, and the distance between the straight segment and the adjacent sidewall of the pole base plate along the width direction of the cover plate body is L3, satisfying 0.1≤L1 / L3≤10.

[0012] Beneficial effects: By further limiting the length of the straight segment and the distance between the straight segment and the pole base plate, the welding quality can be further improved. If L1 / L3 is too large, the welding area is too large, which makes the pole base plate prone to deformation during welding, and the surrounding plastic parts are prone to heat melting. If L1 / L3 is too small, the welding area is too small, and the welding is more difficult.

[0013] In one optional embodiment, the distance between the two straight segments and the sidewall of their respective adjacent pole base plates along the width direction of the cover plate body is equal, satisfying L4=2×L3+L2, 2 / 3≤L2 / L3≤2.

[0014] Beneficial effects: Setting the same spacing between the two straight segments and the side wall of the pole base plate along the width direction of the cover plate body, that is, setting the raceway hole in the middle position of the pole base plate, is conducive to the uniform force distribution around the pole base plate, reducing stress concentration, and further reducing the risk of defects such as deformation, material expansion, and breakage in the weak area of ​​the pole base plate.

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

[0016] Beneficial effects: By controlling the dimensions of the straight section along the length of the cover plate body within a suitable range, it is easy to press-fit welding. If L1 is too large, the straight section will be too long, and it will be easy to deform during welding. Furthermore, if the welding time is too long, it will easily cause the insulation components around the pole base plate to melt. If L1 is too small, the current flow area will be small and the current flow capacity will be weak.

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

[0018] Beneficial effects: By controlling the dimensions of the arc segment along the width of the cover plate body within a suitable range, welding is facilitated. If L2 is too small, the raceway hole will be too narrow, making welding too difficult, and the flow area will be small, resulting in weak flow capacity. At the same time, the connector needs to be compatible with the raceway hole, which also indirectly controls the width range of the connector. If the width of the connector is too small, it will be difficult to form the connector.

[0019] In one optional embodiment, the distance L3 between the straight segment and the adjacent sidewall of the pole base plate along the width direction of the cover plate body satisfies 1.5mm≤L3≤10mm.

[0020] Beneficial effects: The area between the straight section and the adjacent sidewall of the pole base plate along the width direction of the cover plate body is the weak area. By controlling the range of the spacing L3, the width of the weak area can be controlled within a suitable range to avoid the weak area being too narrow, which would cause deformation and breakage during welding. If the weak area is too wide, space and materials will be wasted.

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

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

[0023] In one optional embodiment, the cell cover assembly further includes a first insulating member and a riveting block, the riveting block being connected to the main body and disposed corresponding to the first surface, and the first insulating member being sandwiched between the riveting block and the cover body.

[0024] Beneficial effects: The first insulating component effectively isolates the electrode post body from the cover plate body, avoiding risks such as short circuits and leakage in the electrode post body. The main body is fixed by the riveting blocks, which can resist external forces such as vibration and impact, improving the installation stability of the electrode post body.

[0025] In one optional embodiment, the cell cover assembly further includes a sealing ring and a second insulating member, the second insulating member being attached to the second surface, the electrode base plate being disposed on the side of the second insulating member away from the second surface, and the sealing ring being sleeved on the outer peripheral wall of the main body and sandwiched between the electrode base plate and the second insulating member and between the main body and the cover body.

[0026] Beneficial effects: By fitting a sealing ring on the outer periphery of the main body, a sealing effect can be achieved, preventing electrolyte leakage inside the battery cell and preventing foreign objects from entering the battery cell. In addition, the sealing ring also has good insulation properties.

[0027] Secondly, the present invention also provides a battery cell, comprising:

[0028] The housing has an opening at at least one end;

[0029] In the aforementioned cell cover assembly, the cover body is disposed over the opening and connected to the housing.

[0030] Beneficial Effects: The battery cell of this invention features a racetrack-shaped cross-section for its terminal body. Compared to the traditional circular cross-section, this provides a larger current-carrying area, enhancing current-carrying capacity and thus improving the cell's fast-charging capability and capacity. By welding the connector to the terminal base plate and controlling the size of the racetrack-shaped holes in the terminal base plate within a suitable range, the welding quality of weak areas in the terminal base plate can be improved, reducing the risk of defects such as deformation, material expansion, and breakage in these areas. Furthermore, the racetrack-shaped projection of the connector along the first direction provides excellent torsional resistance, allowing it to better withstand vibrations or external impacts during battery charge-discharge cycles after welding, reducing the risk of weld cracking. The increased contact area of ​​the connector also reduces localized heating caused by uneven current distribution.

[0031] Thirdly, the present invention also provides a battery pack comprising: at least one of the above-described battery cells.

[0032] Beneficial effects: Since the battery pack includes battery cells, it has the same effects as the battery cells, which will not be elaborated here. Attached Figure Description

[0033] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

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

[0035] Figure 2 This is 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 the raceway hole in a battery cell cover assembly according to an embodiment of the present invention;

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

[0039] Explanation of reference numerals in the attached figures:

[0040] 1. Cover plate body; 101. Mounting hole; 2. Pole post body; 201. Main body; 202. Connector; 3. Pole post base plate; 301. Runway hole; 3011. Straight section; 3012. Arc section; 4. First insulating component; 5. Riveting block; 6. Sealing ring; 7. Second insulating component. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] The following is combined with Figures 1 to 5 The following describes embodiments of the present invention.

[0043] According to embodiments of the present invention, in one aspect, such as Figure 1 and Figure 2As shown, a battery cell cover assembly is provided, mainly including: a cover body 1, a terminal body 2, and a terminal base plate 3. The cover body 1 is provided with a mounting hole 101. The terminal body 2 is inserted into the mounting hole 101. The terminal body 2 includes a main body 201 and a connecting body 202 connected to each other. The orthographic projection of the main body 201 and the connecting body 202 along a first direction is racetrack-shaped. The main body 201 extends to the first surface of the cover body 1. The pole base plate 3 is located on the second surface of the cover plate body 1 opposite to the first surface. The pole base plate 3 has a raceway hole 301. The connector 202 passes through the raceway hole 301 and is welded to the pole base plate 3. The cross section of the raceway hole 301 perpendicular to the first direction includes two straight segments 3011 and two arc segments 3012. The two straight segments 3011 are arranged relatively spaced along the width direction of the cover plate body 1, and the two arc segments 3012 are arranged relatively spaced along the length direction of the cover plate 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 plate body 1 is L2, and the dimension of the pole base plate 3 along the width direction of the cover plate body 1 is L4, satisfying 0.25≤L2 / L4≤0.5.

[0045] Therefore, the cell cover assembly provided in this embodiment of the invention features a racetrack-shaped cross-section for the main body 201 of the electrode post 2. Compared to the traditional circular cross-section, this provides a larger current-carrying area, enhancing current-carrying capacity and thus improving the cell's fast-charging capability and capacity. By welding the connector 202 to the electrode post base plate 3 and controlling the size of the racetrack hole 301 in the electrode post base plate 3 within a suitable range, the welding quality of the weak areas of the electrode post base plate 3 can be improved, reducing the risk of defects such as deformation, material expansion, and breakage in the weak areas. If L2 / L4 is too small, the connector 202 will be too small, making it difficult to form the electrode post 2 and resulting in a smaller welding area and greater welding difficulty. If L2 / L4 is too large, the width of the weak area will be too narrow, easily leading to deformation and breakage defects during welding. In addition, the orthographic projection of the connector 202 along the first direction is racetrack-shaped, which has good anti-torsion performance. After welding, it can better withstand vibration or external impact during battery charge and discharge cycles, 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 passes through the runway hole 301 and is then welded together by press fitting. For example... Figure 5As shown, the orthographic projection of the connector 202 in the first direction falls onto the orthographic projection of the main body 201 in the first direction, meaning the size of the connector 202 is smaller than the size of the main body 201 to facilitate welding. The connector 202 is fixed to one end of the main body 201 near the pole base plate 3. The first direction is also the axial direction of the pole body 2, which is also the thickness direction of the cover plate body 1, as shown... Figure 1 As indicated by arrow H in the diagram. The length direction of the cover plate body 1 is as follows. Figure 1 As indicated by arrow L in the diagram, the width direction of the cover body 1 is as follows: Figure 1 As indicated by the arrow W in the diagram.

[0047] It should be noted that the cell cover assembly in this embodiment is applied to the blade battery. The cover body 1 of the blade battery has a large aspect ratio, that is, the length of the cover body 1 is large and the width is small. Currently, the industry has increasingly higher requirements for the charge and discharge rate of batteries, which requires an increase in the current carrying capacity of the terminal body 2, that is, an increase in the cross-sectional area of ​​the terminal body 2. In the prior art, the cross-section of the terminal body 2 is usually circular. Since the width of the cover body 1 of the blade battery is small, it is not convenient to increase the diameter of the circle. Therefore, the prior art usually sets two cylindrical terminals to increase the current carrying capacity. This setting leads to a complicated assembly process and low assembly efficiency of the cover assembly. In this embodiment, the main body 201 of the terminal body 2 is set as a racetrack shape, and its dimension along the length direction of the cover body 1 is increased. This can improve the current carrying capacity without increasing the number of terminal bodies 2, thus ensuring assembly efficiency.

[0048] It should be noted that in this embodiment, the dimensions of the main body 201 along the length of the cover plate body 1 should be increased as much as possible. Under the premise that the width of the cover plate body 1 is limited, the cross-sectional area of ​​the main body 201 should also be increased as much as possible to improve the flow area of ​​the main body 201, thereby having good flow capacity.

[0049] In one embodiment, such as Figure 3 and Figure 4 As shown, the dimension of the straight segment 3011 along the length direction of the cover plate body 1 is L1, and the distance between the straight segment 3011 and the adjacent sidewalls of the pole base plate 3 along the width direction of the cover plate body 1 is L3, satisfying 0.1≤L1 / L3≤10. By further limiting the length dimension of the straight segment 3011 and the distance between the straight segment 3011 and the pole base plate 3, the welding quality can be further improved. If L1 / L3 is too large, the welding area is too large, which makes the pole base plate 3 easy to deform during welding, and the surrounding plastic parts are prone to heat melting. If L1 / L3 is too small, the welding area is too small, and the welding difficulty is greater.

[0050] Specifically, the straight segment 3011 extends along the length of the cover plate body 1, so L1 is the length dimension 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 distance between the straight segment 3011 and the adjacent sidewall of the pole base plate 3 along the width direction of the cover plate body 1 is usually smaller than the distance between the arc segment 3012 and the adjacent sidewall of the pole base plate 3 along the length direction of the cover plate body 1. Therefore, the area between the straight segment 3011 and the adjacent sidewall of the pole base plate 3 along the width direction of the cover plate body 1 is a weak area, and L3 is the minimum width of the weak area.

[0051] In one embodiment, such as Figure 3 As shown, the distance between the two straight segments 3011 and the sidewalls of their respective adjacent pole base plates 3 along the width direction of the cover plate body 1 is equal. That is, the raceway hole 301 is located at the center of the pole base plate 3, satisfying L4=2×L3+L2, 2 / 3≤L2 / L3≤2. Setting the distance between the two straight segments 3011 and the sidewalls of the pole base plate 3 along the width direction of the cover plate body 1 to be the same, that is, setting the raceway hole 301 at the middle position of the pole base plate 3, is beneficial to the uniform stress distribution around the pole base plate 3, reducing stress concentration, and further reducing the risk of defects such as deformation, material expansion, and breakage in the weak areas of the pole base plate 3.

[0052] In one embodiment, such as Figure 3 As shown, the dimension L1 of the straight segment 3011 along the length of the cover plate body 1 satisfies 1mm≤L1≤30mm. By controlling the dimension of the straight segment 3011 along the length of the cover plate body 1 within a suitable range, it is convenient for press-fit welding. If L1 is too large, the straight segment 3011 will be too long, which will easily deform during welding and the welding time will be too long, which may cause the insulation parts around the pole base plate 3 to melt. If L1 is too small, the current flow area will be small and the current flow capacity will be weak.

[0053] In one embodiment, such as Figure 3 As shown, the dimension L2 of the arc segment 3012 along the width direction of the cover plate body 1 satisfies 2.5mm≤L2≤15mm. By controlling the dimension of the arc segment 3012 along the width direction of the cover plate body 1 within a suitable range, welding is facilitated. If L2 is too small, the raceway hole 301 will be too narrow, making welding too difficult, and the flow area will be small, resulting in weak flow capacity. At the same time, the connector 202 needs to be adapted to the raceway hole 301, which also indirectly controls the width range of the connector 202. If the width of the connector 202 is too small, the connector 202 will be difficult to form.

[0054] In one embodiment, such as Figure 3As shown, the distance L3 between the straight segment 3011 and the adjacent sidewall of the pole base plate 3 along the width direction of the cover plate body 1 satisfies 1.5mm≤L3≤10mm. By controlling the range of the distance L3, the width of the weak area can be controlled within a suitable range, avoiding the weak area being too narrow, which would lead to deformation and breakage during welding. If the weak area is too wide, space and materials will be wasted.

[0055] In one embodiment, such as Figure 3 As shown, the dimension L4 of the pole base 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 base plate 3 within a suitable range, the welding quality of the weak area can be further improved.

[0056] In one embodiment, such as Figure 1 and Figure 2 As shown, the battery cell cover assembly also includes a first insulating member 4 and a riveting block 5. The riveting block 5 is connected to the main body 201 and is disposed corresponding to the first surface. The first insulating member 4 is sandwiched between the riveting block 5 and the cover body 1. The first insulating member 4 can effectively isolate the electrode post body 2 and the cover body 1, avoiding the risk of short circuits or leakage in the electrode post body 2. By fixing the main body 201 with the riveting block 5, it can resist external forces such as vibration and impact, improving the installation stability of the electrode post body 2. The first insulating member 4 and the riveting block 5 can protrude from the first surface, and correspondingly, the main body 201 can extend beyond the first surface of the cover body 1.

[0057] It should be noted that after the cell cover assembly is installed with the cell housing, the first surface of the cover body 1 is located on the outer side, and the second surface is located on the inner side. In addition, the electrode base plate 3 is located on the inner side of the cover body 1, and the main body 201 needs to extend and partially protrude from the outer side of the cover body 1.

[0058] In one embodiment, such as Figure 1 and Figure 2 As shown, the cell cover assembly also includes a sealing ring 6 and a second insulating member 7. The second insulating member 7 is attached to the second surface, and the electrode base plate 3 is located on the side of the second insulating member 7 away from the second surface. The sealing ring 6 is sleeved on the outer peripheral wall of the main body 201 and sandwiched between the electrode base plate 3 and the second insulating member 7, as well as between the main body 201 and the cover body 1. By sleeved on the outer peripheral wall of the main body 201, a sealing function can be achieved, preventing electrolyte leakage from the cell and preventing external foreign objects from entering the cell. In addition, the sealing ring 6 also has good insulation properties.

[0059] It should be noted that the embodiments of the present invention do not limit the material of the cover plate body 1. Any existing material can be selected as needed, for example, the cover plate body 1 is a plain aluminum plate.

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

[0061] Example 1:

[0062] The straight segment 3011 of the raceway hole 301 has a length dimension L1 of 6 mm along the length of the cover plate body 1, and the arc segment 3012 of the raceway hole 301 has a width dimension L2 of 2.8 mm along the width of the cover plate body 1. The distance L3 between the straight segment 3011 and the adjacent sidewall of the pole base plate 3 along the width of the cover plate body 1 is 1.5 mm. Therefore, the dimension L4 of the pole base plate 3 along the width of the cover plate body 1 is 5.8 mm, L1 / L3 = 4, and L2 / L4 = 0.48. The test verification results after the battery cell production line are shown in Table 1.

[0063] Example 2:

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

[0065] Example 3:

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

[0067] Example 4:

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

[0069] Example 5:

[0070] The straight segment 3011 of the raceway hole 301 has a length dimension L1 of 5mm along the cover plate body 1, and the arc segment 3012 of the raceway hole 301 has a width dimension L2 of 3mm along the cover plate body 1. The distance L3 between the straight segment 3011 and the adjacent sidewall of the pole base plate 3 along the width direction of the cover plate body 1 is 2mm. Therefore, the dimension L4 of the pole base plate 3 along the width direction of the cover plate body 1 is 7mm. L1 / L3 = 2.5, L2 / L4 = 0.43. The test verification results after the battery cell production line are shown in Table 1.

[0071] Example 6:

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

[0073] Example 7:

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

[0075] Example 8:

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

[0077] Example 9:

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

[0079] Example 10:

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

[0081] Comparative Example 1:

[0082] The straight segment 3011 of the raceway hole 301 has a length L1 of 8.5 mm along the length of the cover plate body 1, and the arc segment 3012 of the raceway hole 301 has a width L2 of 3.2 mm along the width of the cover plate body 1. The distance L3 between the straight segment 3011 and the adjacent sidewall of the pole base plate 3 along the width of the cover plate body 1 is 1 mm, which is less than 1.5 mm. Therefore, the width L4 of the pole base plate 3 along the width of the cover plate body 1 is 5.2 mm. L1 / L3 = 8.5, L2 / L4 = 0.62, which is greater than 0.5. The test verification results after the battery cell production line are shown in Table 1.

[0083] Comparative Example 2:

[0084] The straight segment 3011 of the raceway hole 301 has a length dimension L1 of 5mm along the length of the cover plate body 1, and the arc segment 3012 of the raceway hole 301 has a width dimension L2 of 4mm along the width of the cover plate body 1. The distance L3 between the straight segment 3011 and the adjacent sidewall of the pole base plate 3 along the width of the cover plate body 1 is 0.8mm, which is less than 1.5mm. Therefore, the dimension L4 of the pole base plate 3 along the width of the cover plate body 1 is 5.6mm. L1 / L3 = 6.25, L2 / L4 = 0.71, which is greater than 0.5. The test verification results after the battery cell production line are shown in Table 1.

[0085] Comparative Example 3:

[0086] The straight segment 3011 of the raceway hole 301 has a length dimension L1 of 24 mm along the length of the cover plate body 1, and the arc segment 3012 of the raceway hole 301 has a width dimension L2 of 2 mm, which is less than 2.5 mm. The distance L3 between the straight segment 3011 and the adjacent sidewall of the pole base plate 3 along the width of the cover plate body 1 is 4 mm. Therefore, the dimension L4 of the pole base plate 3 along the width of the cover plate body 1 is 10 mm. L1 / L3 = 6, L2 / L4 = 0.2, which is less than 0.25. The test verification results after the cell production line are shown in Table 1.

[0087] Comparative Example 4:

[0088] The straight segment 3011 of the raceway hole 301 has a length L1 of 22.5 mm along the length of the cover plate body 1, and the arc segment 3012 of the raceway hole 301 has a width L2 of 1.5 mm, which is less than 2.5 mm. The distance L3 between the straight segment 3011 and the adjacent sidewall of the pole base plate 3 along the width of the cover plate body 1 is 3.8 mm. Therefore, the width L4 of the pole base plate 3 along the width of the cover plate body 1 is 9.1 mm. L1 / L3 = 5.92, L2 / L4 = 0.16, which is less than 0.25. The test verification results after the battery cell production line are shown in Table 1.

[0089] Comparative Example 5:

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

[0091] Comparative Example 6:

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

[0093] Table 1: Test Results

[0094]

[0095] As shown in Table 1, in Examples 1 to 10, the following conditions are met: 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. The welding quality between the pole base plate 3 and the pole body 2 is good.

[0096] In Comparative Example 1 and Comparative Example 2, L3 is less than 1.5 mm and L2 / L4 is greater than 0.5. The width of the weak area is too narrow, which leads to deformation and fracture defects in the weak area 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 size of the connector 202 of the pole body 2 is too small, making it difficult to form and the welding area is small, making welding more difficult.

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

[0099] According to an embodiment of the present invention, another aspect provides a battery cell, comprising: a housing and a battery cell cover assembly. The housing has an opening at at least one end, and an electrode assembly is disposed within the housing. The cover body 1 of the battery cell cover assembly covers the opening and is connected to the housing.

[0100] The battery cell provided in this embodiment of the invention features a racetrack-shaped cross-section for the main body 201 of the terminal body 2. Compared to the traditional circular cross-section, this provides a larger current-carrying area, enhancing current-carrying capacity and thus improving the cell's fast-charging capability and capacity. By welding the connector 202 to the terminal base plate 3 and controlling the size of the racetrack hole 301 in the terminal base plate 3 within a suitable range, the welding quality of the weak areas of the terminal base plate 3 can be improved, reducing the risk of defects such as deformation, material expansion, and breakage in these areas. Furthermore, the racetrack shape of the connector 202 along the first direction provides excellent torsional resistance, allowing it to better withstand vibrations or external impacts during battery charge-discharge cycles after welding, reducing the risk of weld cracking. The increased contact area of ​​the connector 202 also reduces localized heating caused by uneven current distribution.

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

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

[0103] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and all such modifications and variations fall within the scope defined by the appended claims.

Claims

1. A cell cover assembly, characterized in that, include: The cover plate body is provided with mounting holes; The pole body is inserted into the mounting hole. The pole body includes a main body and a connecting body connected to each other. The orthographic projection of the main body and the connecting body along the first direction is racetrack-shaped. The main body extends to the first surface of the cover plate body. A pole base plate is disposed on the second surface of the cover plate body opposite to the first surface. A racetrack hole is formed on the pole base plate. The connector passes through the racetrack hole and is welded to the pole base plate. The cross section of the racetrack hole perpendicular to the first direction includes two straight segments and two arc segments. The two straight segments are arranged relatively spaced along the width direction of the cover plate body, and the two arc segments are arranged relatively spaced along the length direction of the cover plate body. The two arc segments are respectively connected to the two ends of the two straight segments on the same side. The arc segment has a dimension L2 along the width direction of the cover plate body, and the pole base plate has a dimension L4 along the width direction of the cover plate body, satisfying 0.25≤L2 / L4≤0.5; The dimension of the straight segment along the length direction of the cover plate body is L1, and the distance between the straight segment and the adjacent sidewall of the pole base plate along the width direction of the cover plate body is L3, satisfying 0.1≤L1 / L3≤10; The distance between the two straight segments and the sidewalls of their respective adjacent pole base plates along the width direction of the cover plate body is equal, satisfying L4=2×L3+L2, 2 / 3≤L2 / L3≤2.

2. The cell cover assembly according to claim 1, characterized in that, The dimension L1 of the straight segment along the length of the cover plate body satisfies 1 mm ≤ L1 ≤ 30 mm.

3. The cell cover assembly according to claim 1, characterized in that, The dimension L2 of the arc segment along the width direction of the cover plate body satisfies 2.5 mm ≤ L2 ≤ 15 mm; And / or, the distance L3 between the straight segment and the adjacent sidewall of the pole base plate along the width direction of the cover plate body satisfies 1.5 mm ≤ L3 ≤ 10 mm.

4. The cell cover assembly according to claim 1, characterized in that, The dimension L4 of the pole base plate along the width direction of the cover plate body satisfies 5.5 mm ≤ L4 ≤ 35 mm.

5. The cell cover assembly according to any one of claims 1 to 4, characterized in that, The cell cover assembly further includes a first insulating component and a riveting block. The riveting block is connected to the main body and is disposed corresponding to the first surface. The first insulating component is sandwiched between the riveting block and the cover body.

6. The cell cover assembly according to claim 5, characterized in that, The cell cover assembly further includes a sealing ring and a second insulating component. The second insulating component is attached to the second surface. The electrode base plate is located on the side of the second insulating component away from the second surface. The sealing ring is sleeved on the outer peripheral wall of the main body and sandwiched between the electrode base plate and the second insulating component, as well as between the main body and the cover body.

7. A battery cell, characterized in that, include: The housing has an opening at at least one end; The cell cover assembly according to any one of claims 1 to 6, wherein the cover body is disposed over the opening and connected to the housing.

8. A battery pack, characterized in that, include: At least one battery cell as described in claim 7.

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