Battery cell cover plate, cover plate assembly and battery cell

Abstract

The present invention relates to the technical field of power batteries, and provides a battery cell cover plate, a cover plate assembly and a battery cell, the battery cell cover plate comprises: a cover plate body having two plate surfaces arranged back to back in the thickness direction of the cover plate body, one of the plate surfaces forming a support surface; the pole hole penetrates through the cover plate body; the supporting convex hull is arranged on the supporting surface in a protruding mode, and the height H1 of the supporting convex hull protruding out of the supporting surface meets the condition that H1 is larger than or equal to (H + 1.0 mm) and smaller than or equal to (H + 2.0 mm); wherein H is the height of the pole protruding out of the supporting surface. When the upper surface of the whole battery pack is impacted by external force, the impact force can be borne by the supporting convex hulls, direct stress of the pole columns is avoided, the short-circuit risk of the battery cell is reduced, the impact external force borne by the supporting convex hulls can be directly dispersed to the cover plate body and even the whole shell of the battery cell, the supporting performance of the shell of the battery cell is exerted, and the mechanical strength of the whole battery pack is improved; and long-term stable operation of the battery cell is ensured. And the supporting convex hulls can also improve the heat dissipation effect of the battery cell and improve the quick charging performance of the battery cell.

Description

Technical Field

[0001] This invention relates to the field of power battery technology, and in particular to a cell cover, a cover assembly, and a cell. Background Technology

[0002] Lithium-ion batteries are widely used in various fields such as transportation power supply, power storage, new energy storage power supply, aerospace and military industry due to their advantages such as large capacity, high operating voltage, strong charge retention capability and long cycle life.

[0003] A battery cell is the smallest unit of a lithium battery pack. In existing technologies, a battery cell typically includes an electrolyte, electrode assembly, bare cell insulating sheet, cover plate, casing, top adhesive patch, and outer insulating film. The casing and cover plate are welded together to form a closed space housing the electrode assembly. The cover plate usually integrates functional areas such as terminals, electrolyte injection holes, and explosion-proof valves. It is sealed to the casing by welding a flat aluminum sheet around its perimeter. The flat aluminum sheet has a planar structure, with the terminals protruding 2–3.5 mm from it. After being assembled within the module or pack, the cells are electrically connected by welding a tab to the top surface of the terminals, and then the tab is glued to the module or pack housing using thermally conductive structural adhesive.

[0004] However, actual research has found that the battery cell only contacts the outside world through the terminals. When the upper surface of the entire pack is impacted by external forces, the terminals are directly subjected to the force, which greatly increases the risk of short circuits in the battery cell. Furthermore, although the battery cell cover plate has a certain supporting strength after being welded to the shell, it is not directly subjected to external forces. As a result, the mechanical strength of the entire pack is low, and the safety and stability of battery operation cannot be guaranteed.

[0005] In view of the above problems, how to reduce the impact of external forces on the terminals, thereby reducing the risk of short circuits in the cells and improving the overall mechanical strength of the battery pack to ensure long-term stable operation of the battery has become an important technical problem that urgently needs to be solved. Summary of the Invention

[0006] This invention provides a cell cover plate, a cover plate assembly, and a cell to solve the defects in the prior art where direct force on the electrode posts easily leads to short circuits and the mechanical strength of the entire battery pack is insufficient. It can effectively reduce the impact of external impact forces on the electrode structure, reduce the risk of cell short circuits, and improve the mechanical strength of the entire pack, ensuring the long-term stable operation of the battery.

[0007] This invention provides a battery cell cover plate, comprising: The cover plate has two plates facing away from each other in its own thickness direction, and one of the plates is formed as a support surface; The pole hole penetrates the cover plate body; A support convex hull is provided protruding from the support surface, and the height H1 protruding from the support surface satisfies: (H+1.0mm)≤H1≤(H+2.0mm); where H is the height of the pole protruding from the support surface.

[0008] According to a battery cell cover plate provided by the present invention, in the direction away from the supporting surface, the cross-sectional area of ​​the supporting protrusion gradually decreases along the direction perpendicular to the thickness of the cover plate body.

[0009] According to the present invention, the taper β of the supporting convex bulge satisfies: 15°≤β≤25°.

[0010] According to a battery cell cover plate provided by the present invention, the distance L0 between the supporting protrusion and the electrode post satisfies: 3mm ≤ L0 ≤ 8mm; and / or, In the width direction of the cover plate, the distance W0 between the supporting protrusion and the edge of the cover plate satisfies: 1mm ≤ W0 ≤ 3mm; and / or, The height H1 of the support bulge protruding from the support surface is: 2.5mm≤H1≤6mm.

[0011] According to the present invention, the supporting bulge is symmetrical about the centerline of the short side of the cover plate body; The distance W0 between the supporting protrusion and the edge of the cover plate is: (W-W1) / 2; where W is the total width of the cover plate and W1 is the total width of the supporting protrusion.

[0012] According to the present invention, a battery cell cover plate is provided on the cover plate body, wherein a welding port is provided corresponding to the position of the electrode tab; the welding port penetrates the cover plate body; A sealing plate is fitted onto the weld joint. The side of the sealing plate facing the weld joint is recessed in a direction away from the weld joint to form a tab receiving cavity, and a protrusion is formed on the side facing away from the weld joint to form the support protrusion.

[0013] According to the present invention, an insulating component is provided on the cavity wall of the electrode receiving cavity.

[0014] The present invention also provides a cover plate assembly, comprising: Any of the above provides the aforementioned cell cover plate; The electrode structure includes an electrode post and a connecting piece; the electrode post passes through the electrode post hole, and the height H of the electrode post protruding from the support surface and the height H1 of the support bulge protruding from the support surface satisfy: (H+1.0mm)≤H1≤(H+2.0mm); one end of the connecting piece is connected to the electrode post, and the other end is used to connect to the electrode tab; An insulating structure is disposed between the electrode structure and the cover plate body for electrical isolation between the electrode structure and the cover plate body.

[0015] According to a cover plate assembly provided by the present invention, the connecting piece includes: The first part has one end connected to the pole post and the other end extending to the welding joint; The second part is inserted through the weld joint and one end is connected to the end of the first part away from the pole post; the height H2 of the second part protruding from the support surface satisfies 0.8mm≤H2≤1.5mm; The third part has one end connected to the end of the second part away from the first part, and the other end extends along the length of the cover plate body.

[0016] The present invention also provides a battery cell, comprising: The housing component has an opening at one end; The cell cover plate or cover plate assembly provided by any of the above-mentioned items, wherein the cover plate body is sealed to the opening; The electrode assembly is disposed within the cavity formed by the housing and the cover plate, and the electrode tabs of the electrode assembly are connected to the electrode posts.

[0017] The present invention provides a cell cover plate, a cover plate assembly, and a cell. After the cell cover plate is assembled into a battery housing, the supporting surface faces outward from the cavity of the housing. After the terminal post passes through the terminal post hole, it protrudes outward from the cavity of the housing together with the supporting protrusion. Since the height H1 of the supporting protrusion protruding from the supporting surface is 1.0mm to 2.0mm greater than the height H of the terminal post protruding from the supporting surface, it can be ensured that the height of the supporting protrusion is higher than the total height after the terminal post is welded to the plate. At the same time, it can be ensured that the space occupied by the supporting protrusion will not have a significant impact on the capacity of the battery pack. When the upper surface of the entire battery pack is subjected to an external impact, the impact force will be absorbed by the supporting protrusion, thereby avoiding direct force on the terminal post and reducing the risk of short circuit in the cell. At the same time, the impact force on the supporting protrusion will be directly distributed to the cover plate body and even the entire housing of the cell, thereby fully utilizing the supporting performance of the cell housing, improving the mechanical strength of the entire pack, and ensuring the long-term stable operation of the cell.

[0018] In addition to the above, the supporting bulge can also increase the heat dissipation area and can directly support the water cooling equipment in the pack as a load-bearing component, so that the water cooling equipment in the pack can directly act on the electrode area, thereby reducing the temperature of the electrode during battery charging and discharging and improving the fast charging performance of the cell. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the battery cell structure provided in an embodiment of the present invention.

[0021] Figure 2 This is a schematic diagram of the structure of the battery cell cover plate provided in an embodiment of the present invention.

[0022] Figure 3 This is a top view of the battery cell cover plate provided in an embodiment of the present invention.

[0023] Figure 4 yes Figure 3 Cross-sectional view along the AA direction.

[0024] Figure 5 This is a schematic diagram of the supporting convex hull structure provided in an embodiment of the present invention.

[0025] Figure 6 This is a cross-sectional view of the supporting convex hull provided in an embodiment of the present invention.

[0026] Figure 7 This is a schematic diagram of the cover plate assembly and the electrode assembly provided in an embodiment of the present invention.

[0027] Figure 8 This is a top view of the battery cell provided in an embodiment of the present invention.

[0028] Figure 9 yes Figure 8 Cross-sectional view along the BB direction.

[0029] Figure 10 yes Figure 9 Enlarged view of section A.

[0030] Figure label: 10. Cover plate; 101. Support surface; 102. Weld joint; 11. Pole post hole; 12. Support protrusion; 121. Pole ear receiving cavity; 122. Insulating component; 20. Electrode structure; 21. Pole post; 22. Connecting piece; 221. First part; 222. Second part; 223. Third part; 30. Insulating structure; 31. First insulating component; 32. Second insulating component; 33. Insulating ring; 40. Housing component; 50. Pole group; 51. Pole ear. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0032] To better understand the cell cover, cover assembly, and cell provided in the embodiments of the present invention, we will first introduce its application background. The cell is the smallest unit of a lithium battery pack. In the traditional cell structure, the shell and cover are fixedly connected by welding to form a closed space that accommodates the electrode assembly. The cover integrates the electrode post, which protrudes from the cover by 2 to 3.5 mm. After being assembled in the module or PACK, the cells are electrically connected by welding the electrode post to the upper surface of the electrode post and then assembled. The electrode post is then glued and fixed to the housing of the module or PACK by thermally conductive structural adhesive.

[0033] However, actual research has found that the battery cell only contacts the outside world through the terminals. When the upper surface of the entire pack is impacted by external forces, the terminals are directly subjected to the force, which greatly increases the risk of short circuits in the battery cell. Furthermore, although the battery cell cover plate has a certain supporting strength after being welded to the shell, it is not directly subjected to external forces. As a result, the mechanical strength of the entire pack is low, and the safety and stability of battery operation cannot be guaranteed.

[0034] In view of the above problems, embodiments of the present invention provide a cell cover plate, a cover plate assembly, and a cell, which can effectively reduce the impact of external impact forces on the electrode structure, reduce the risk of cell short circuit, improve the mechanical strength of the entire pack, and ensure the long-term stable operation of the battery.

[0035] The following is combined with Figures 1 to 10 The present invention describes a cell cover plate, a cover plate assembly, and a cell.

[0036] Reference Figure 1 A battery cell cover plate includes a cover plate body 10, a terminal hole 11, and a support protrusion 12; wherein, the cover plate body 10 has two plates arranged back to back in its own thickness direction, and one of the plates forms a support surface 101; the terminal hole 11 penetrates the cover plate body 10; the support protrusion 12 protrudes from the support surface 101, and its height H1 protruding from the support surface 101 satisfies: (H+1.0mm)≤H1≤(H+2.0mm); H is the height of the terminal 21 protruding from the support surface 101.

[0037] In practical applications, after assembling the battery housing using the aforementioned cell cover plate, the support surface 101 faces the outside of the housing cavity. The terminal post 21 protrudes out of the terminal post hole 11 and extends out of the housing cavity together with the support protrusion 12. Since the height H1 of the support protrusion 12 protruding from the support surface 101 is 1.0mm to 2.0mm greater than the height H of the terminal post 21 protruding from the support surface 101, it can be ensured that the height of the support protrusion 12 is higher than the total height of the terminal post 21 after welding the tab. At the same time, it can be ensured that the space occupied by the support protrusion 12 will not have a significant impact on the capacity of the battery pack. When the upper surface of the entire battery pack is subjected to external impact, the impact force will be absorbed by the support protrusion 12, thereby avoiding direct force on the terminal post and reducing the risk of short circuit in the cell. At the same time, the impact force on the support protrusion 12 will be directly distributed to the cover plate body 10 and even the entire housing of the cell, thereby fully utilizing the support performance of the cell housing, improving the mechanical strength of the entire pack, and ensuring the long-term stable operation of the cell.

[0038] In addition to the above, the supporting protrusion 12 can also increase the heat dissipation area and can directly support the water cooling equipment in the Pack as a load-bearing component, so that the water cooling equipment in the Pack can directly act on the electrode area, thereby reducing the temperature of the electrode under battery charging and discharging conditions and improving the fast charging performance of the cell.

[0039] It is understandable that the cover plate 10, as the supporting foundation for various components, can have its shape, size, and material parameters selected and designed according to actual needs, such as the shape, size specifications, and welding strength requirements of the battery cell.

[0040] In one example of the present invention, the cover plate 10 is configured as a rectangular aluminum plate having three directions: a length direction extending along its long side, a width direction extending along its short side, and a thickness direction perpendicular to its surface.

[0041] It should be clarified here that, unless otherwise specified, the length, width and thickness directions mentioned below are based on the cover plate 10.

[0042] In the thickness direction, the cover plate 10 has two plate surfaces. After the cover plate 10 is used to assemble the battery cell housing, one plate surface faces the inner side of the housing cavity, and the other plate surface faces the outer side of the housing cavity. The plate surface of the cover plate 10 facing the outer side of the housing cavity is the aforementioned support surface 101. The terminal hole 11 penetrates the cover plate 10, so that after the terminal 21 passes through the terminal hole 11, one end of it can be located inside the cavity of the battery cell housing and connected to the electrode tab 51 of the electrode group 50, and the other end protrudes outside the cavity of the battery cell housing and protrudes from the support surface 101 for current extraction. The tab is welded to the end of the terminal 21 that protrudes from the support surface 101, thereby electrically connecting different battery cells into a group. The support protrusion 12 protrudes from the support surface 101, thereby being able to withstand the impact force on the battery pack.

[0043] It is understandable that there can be one or more support bulges 12. The support bulges 12 can be rectangular, circular, or other sizes or irregular polygons. In addition, the length and width dimensions of the support bulges 12, the height of the bulges protruding from the support surface 101, and other parameters need to be further designed according to the support strength requirements. This will be explained in detail below and will not be introduced here.

[0044] In some optional examples of the present invention, the supporting protrusion 12 can be formed on the cover plate 10 using different processes according to different actual needs, including but not limited to welding or integral forming.

[0045] In detail, welding refers to welding after segmented processing, while integral forming includes, but is not limited to, stamping and integral casting.

[0046] Further research revealed that inside the cell, the terminal 21 needs to be welded to the bent tab 51 via the connecting piece 22. Therefore, sufficient bending space for the tab 51 needs to be reserved inside the cell. However, this will result in a large gap between the electrode assembly 50 and the plastic under the cover plate. The existence of this gap wastes the internal space of the cell and affects the cell capacity.

[0047] In view of the above problems, in a further example of the present invention, reference is made to... Figures 2 to 6 The cover plate 10 is provided with a welding port 102 corresponding to the position of the electrode lug 51, and the welding port 102 penetrates the cover plate 10. A sealing plate is sealed to the welding port 102. The side of the sealing plate facing the welding port 102 is recessed in the direction away from the welding port 102 to form an electrode lug receiving cavity 121, and at the same time, a protrusion is formed on the side away from the welding port 102, thereby constituting a supporting protrusion 12.

[0048] With this configuration, since the welding port 102 corresponds to the position of the tab 51, the tab 51 can pass through the welding port 102 and be bent outside the cell and welded to the connecting piece 22. Then, the sealing plate is sealed and connected to the welding port 102. While sealing the welding port 102, the connecting piece 22 with the tab 51 welded on is accommodated in the tab receiving cavity 121, and a supporting protrusion 12 is formed on the supporting surface 101. The setting of the tab receiving cavity 121 means that the bent tab 51 does not need to occupy the internal space of the cell. Therefore, there is no need to reserve a large gap between the cover plate 10 and the electrode group 50, which reduces the waste of internal space of the cell and increases the capacity of the cell in the same volume.

[0049] Furthermore, the sealing plate and the cover plate 10 can be fixed by welding, and the electrode lug receiving cavity 121 on the sealing plate is formed by stamping.

[0050] Furthermore, an insulating component 122 is provided on the cavity wall of the tab receiving cavity 121. In this way, the insulating component 122 can achieve electrical isolation between the tab 51 and the connecting piece 22 and the sealing plate, thereby achieving electrical isolation between the tab 51 and the cover plate body 10.

[0051] It is understandable that the number of support protrusions 12 formed in the above manner is greater than or equal to the number of pole hole 11 on the cover plate 10. For example, when there is one pole hole 11, the number of support protrusions 12 is one or more; when there are two pole holes 11, the number of support protrusions 12 is two or more. In this way, welding channels can be provided for different pole tabs 51 and connecting pieces 22.

[0052] To give a further example, an explosion-proof valve can also be integrated into the cover plate 10, with the electrode post hole 11 separated from the explosion-proof valve by a supporting protrusion 12. This configuration can achieve thermoelectric separation, preventing the high-temperature gases, flames, corrosive electrolytes, and other high-temperature ejected materials from affecting the electrode post 21 in the event of thermal runaway of the battery cell, thereby avoiding safety risks caused by secondary short circuits or thermal propagation in the event of thermal runaway of the battery cell.

[0053] As a specific example of the present invention, the cover plate body 10 is provided with a pole post hole 11 and a support protrusion 12 is provided, and the support protrusion 12 is located on one side of the pole post hole 11 in the length direction of the cover plate body 10.

[0054] In one example of the present invention, the cross-section of the supporting convex 12 is rectangular so that it can be adapted to the shape of the supporting surface 101, thereby maximizing the use of the space on the supporting surface 101.

[0055] Furthermore, in the direction away from the support surface 101, the cross-sectional area of ​​the support protrusion 12 gradually decreases along the direction perpendicular to the thickness of the cover plate 10. With this configuration, the tapered stamping on the sealing plate is easy to achieve, resulting in a high production yield. At the same time, when the space above the support surface 101 along the length of the cover plate 10 is limited, the length and volume of the space accommodating the tab 51 can be maximized, providing sufficient accommodating space for the tab 51 and the connecting piece 22.

[0056] Furthermore, the taper β of the supporting convex hull 12 satisfies: 15°≤β≤25°.

[0057] In one example of the present invention, the distance L0 between the supporting protrusion 12 and the electrode post 21 satisfies: 3mm ≤ L0 ≤ 8mm. This setting satisfies the safety threshold of creepage distance under the energized condition of the battery cell, effectively avoids creepage channels formed between the electrode post 21 and the supporting protrusion 12 due to excessive distance, and reduces the risk of short circuit. At the same time, it also avoids the waste of space caused by excessive spacing between the two, and makes full use of the space on the cover plate 10.

[0058] In one example of the present invention, the distance W0 between the supporting protrusion 12 and the edge of the cover plate 10 in the width direction satisfies: 1mm ≤ W0 ≤ 3mm. With this configuration, if the distance between the supporting protrusion 12 and the edge of the cover plate 10 is too small, it will affect the welding strength between the cover plate 10 and the housing component 40. Furthermore, when the battery cell is covered with an outer insulating film, the outer insulating film may fold over to a width that is too small, easily causing the outer insulating film to warp. By ensuring that the distance W0 between the supporting protrusion 12 and the edge of the cover plate 10 satisfies 1mm ≤ W0 ≤ 3mm, sufficient welding operation space and folding allowance for the outer insulating film can be maintained at the edge of the cover plate 10, thereby guaranteeing the welding strength between the cover plate 10 and the housing component 40 and the covering quality of the outer insulating film.

[0059] Furthermore, the supporting bulge 12 is symmetrical about the centerline of the short side of the cover plate 10. Thus, the distance W0 between the supporting bulge 12 and the edge of the cover plate 10 is: W0 = (W - W1) / 2. Where W is the total width of the cover plate 10 and W1 is the total width of the supporting bulge 12.

[0060] Furthermore, the total length L of the cover plate 10 is 80mm≤L≤200mm, and the total width W of the cover plate 10 is 12mm≤W≤26mm.

[0061] To verify the effectiveness of the above scheme, different DOEs were arranged for the parameter value range provided in the embodiments of the present invention. Combined with simulation analysis and cell safety testing, the results are as follows.

[0062] Example 1 The total length L of the cover plate 10 is 90mm, the total width W of the cover plate 10 is 12.5mm, the distance L0 between the supporting protrusion 12 and the pole post 21 is 3mm, the total width W1 of the supporting protrusion 12 is 8mm, the height H of the pole post 21 protruding from the supporting surface 101 is 1.5mm, the height H1 of the supporting protrusion 12 protruding from the cover plate 10 is 2.6mm, the distance W0 between the supporting protrusion 12 and the edge of the cover plate 10 is 2.25mm, and the height difference between the supporting protrusion 12 and the pole post 21 protruding from the supporting surface 101 is H1-H=1.10mm.

[0063] According to the simulation analysis of PACK in accordance with national standards, when the battery pack is subjected to mechanical impact in the thickness direction of the cover plate 10, the stress at the position of the cell terminal 21 does not change significantly. In addition, 5 cells were randomly selected for safety testing, and no obvious fire or explosion problems were found, indicating that the force at the position of terminal 21 is not significant and terminal 21 has not undergone significant deformation.

[0064] Example 2 The total length L of the cover plate 10 is 100mm, the total width W of the cover plate 10 is 14mm, the distance L0 between the supporting protrusion 12 and the pole post 21 is 3.5mm, the total width W1 of the supporting protrusion 12 is 10mm, the height H of the pole post 21 protruding from the supporting surface 101 is 1.6mm, the height H1 of the supporting protrusion 12 protruding from the cover plate 10 is 2.8mm, the distance W0 between the supporting protrusion 12 and the edge of the cover plate 10 is 2mm, and the height difference between the supporting protrusion 12 and the pole post 21 protruding from the supporting surface 101 is H1-H=1.20mm.

[0065] According to the simulation analysis of PACK in accordance with national standards, when the battery pack is subjected to mechanical impact in the thickness direction of the cover plate 10, the stress at the position of the cell terminal 21 does not change significantly. In addition, 5 cells were randomly selected for safety testing, and no obvious fire or explosion problems were found, indicating that the force at the position of terminal 21 is not significant and terminal 21 has not undergone significant deformation.

[0066] Example 3 The total length L of the cover plate 10 is 110mm, the total width W of the cover plate 10 is 15mm, the distance L0 between the supporting protrusion 12 and the pole post 21 is 4mm, the total width W1 of the supporting protrusion 12 is 11mm, the height H of the pole post 21 protruding from the supporting surface 101 is 2mm, the height H1 of the supporting protrusion 12 protruding from the cover plate 10 is 3mm, the distance W0 between the supporting protrusion 12 and the edge of the cover plate 10 is 2mm, and the height difference between the supporting protrusion 12 and the pole post 21 protruding from the supporting surface 101 is H1-H=1.00mm.

[0067] According to the simulation analysis of PACK in accordance with national standards, when the battery pack is subjected to mechanical impact in the thickness direction of the cover plate 10, the stress at the position of the cell terminal 21 does not change significantly. In addition, 5 cells were randomly selected for safety testing, and no obvious fire or explosion problems were found, indicating that the force at the position of terminal 21 is not significant and terminal 21 has not undergone significant deformation.

[0068] Example 4 The total length L of the cover plate 10 is 120mm, the total width W of the cover plate 10 is 16mm, the distance L0 between the supporting protrusion 12 and the pole post 21 is 4.5mm, the total width W1 of the supporting protrusion 12 is 12mm, the height H of the pole post 21 protruding from the supporting surface 101 is 2.5mm, the height H1 of the supporting protrusion 12 protruding from the cover plate 10 is 3.5mm, the distance W0 between the supporting protrusion 12 and the edge of the cover plate 10 is 2mm, and the height difference between the supporting protrusion 12 and the pole post 21 protruding from the supporting surface 101 is H1-H=1.00mm.

[0069] According to the simulation analysis of PACK in accordance with national standards, when the battery pack is subjected to mechanical impact in the thickness direction of the cover plate 10, the stress at the position of the cell terminal 21 does not change significantly. In addition, 5 cells were randomly selected for safety testing, and no obvious fire or explosion problems were found, indicating that the force at the position of terminal 21 is not significant and terminal 21 has not undergone significant deformation.

[0070] Example 5 The total length L of the cover plate 10 is 130mm, the total width W of the cover plate 10 is 18mm, the distance L0 between the supporting protrusion 12 and the pole post 21 is 5mm, the total width W1 of the supporting protrusion 12 is 14mm, the height H of the pole post 21 protruding from the supporting surface 101 is 2.8mm, the height H1 of the supporting protrusion 12 protruding from the cover plate 10 is 4mm, the distance W0 between the supporting protrusion 12 and the edge of the cover plate 10 is 2mm, and the height difference between the supporting protrusion 12 and the pole post 21 protruding from the supporting surface 101 is H1-H=1.20mm.

[0071] According to the simulation analysis of PACK in accordance with national standards, when the battery pack is subjected to mechanical impact in the thickness direction of the cover plate 10, the stress at the position of the cell terminal 21 does not change significantly. In addition, 5 cells were randomly selected for safety testing, and no obvious fire or explosion problems were found, indicating that the force at the position of terminal 21 is not significant and terminal 21 has not undergone significant deformation.

[0072] Example 6 The total length L of the cover plate 10 is 140mm, the total width W of the cover plate 10 is 20mm, the distance L0 between the supporting protrusion 12 and the pole post 21 is 5.5mm, the total width W1 of the supporting protrusion 12 is 15mm, the height H of the pole post 21 protruding from the supporting surface 101 is 3.0mm, the height H1 of the supporting protrusion 12 protruding from the cover plate 10 is 4.6mm, the distance W0 between the supporting protrusion 12 and the edge of the cover plate 10 is 2.5mm, and the height difference between the supporting protrusion 12 and the pole post 21 protruding from the supporting surface 101 is H1-H=1.60mm.

[0073] According to the simulation analysis of PACK in accordance with national standards, when the battery pack is subjected to mechanical impact in the thickness direction of the cover plate 10, the stress at the position of the cell terminal 21 does not change significantly. In addition, 5 cells were randomly selected for safety testing, and no obvious fire or explosion problems were found, indicating that the force at the position of terminal 21 is not significant and terminal 21 has not undergone significant deformation.

[0074] Example 7 The total length L of the cover plate 10 is 150mm, the total width W of the cover plate 10 is 22mm, the distance L0 between the supporting protrusion 12 and the pole post 21 is 6mm, the total width W1 of the supporting protrusion 12 is 16mm, the height H of the pole post 21 protruding from the supporting surface 101 is 3.2mm, the height H1 of the supporting protrusion 12 protruding from the cover plate 10 is 5mm, the distance W0 between the supporting protrusion 12 and the edge of the cover plate 10 is 3mm, and the height difference between the supporting protrusion 12 and the pole post 21 protruding from the supporting surface 101 is H1-H=1.80mm.

[0075] According to the simulation analysis of PACK in accordance with national standards, when the battery pack is subjected to mechanical impact in the thickness direction of the cover plate 10, the stress at the position of the cell terminal 21 does not change significantly. In addition, 5 cells were randomly selected for safety testing, and no obvious fire or explosion problems were found, indicating that the force at the position of terminal 21 is not significant and terminal 21 has not undergone significant deformation.

[0076] Example 8 The total length L of the cover plate 10 is 160mm, the total width W of the cover plate 10 is 24mm, the distance L0 between the supporting protrusion 12 and the pole post 21 is 6.5mm, the total width W1 of the supporting protrusion 12 is 18mm, the height H of the pole post 21 protruding from the supporting surface 101 is 3.5mm, the height H1 of the supporting protrusion 12 protruding from the cover plate 10 is 5mm, the distance W0 between the supporting protrusion 12 and the edge of the cover plate 10 is 3mm, and the height difference between the supporting protrusion 12 and the pole post 21 protruding from the supporting surface 101 is H1-H=1.50mm.

[0077] According to the simulation analysis of PACK in accordance with national standards, when the battery pack is subjected to mechanical impact in the thickness direction of the cover plate 10, the stress at the position of the cell terminal 21 does not change significantly. In addition, 5 cells were randomly selected for safety testing, and no obvious fire or explosion problems were found, indicating that the force at the position of terminal 21 is not significant and terminal 21 has not undergone significant deformation.

[0078] Example 9 The total length L of the cover plate 10 is 180mm, the total width W of the cover plate 10 is 25mm, the distance L0 between the supporting protrusion 12 and the pole post 21 is 7mm, the total width W1 of the supporting protrusion 12 is 20mm, the height H of the pole post 21 protruding from the supporting surface 101 is 3.6mm, the height H1 of the supporting protrusion 12 protruding from the cover plate 10 is 5.5mm, the distance W0 between the supporting protrusion 12 and the edge of the cover plate 10 is 2.5mm, and the height difference between the supporting protrusion 12 and the pole post 21 protruding from the supporting surface 101 is H1-H=1.90mm.

[0079] According to the simulation analysis of PACK in accordance with national standards, when the battery pack is subjected to mechanical impact in the thickness direction of the cover plate 10, the stress at the position of the cell terminal 21 does not change significantly. In addition, 5 cells were randomly selected for safety testing, and no obvious fire or explosion problems were found, indicating that the force at the position of terminal 21 is not significant and terminal 21 has not undergone significant deformation.

[0080] Example 10 The total length L of the cover plate 10 is 200mm, the total width W of the cover plate 10 is 26mm, the distance L0 between the supporting protrusion 12 and the pole post 21 is 8mm, the total width W1 of the supporting protrusion 12 is 22mm, the height H of the pole post 21 protruding from the supporting surface 101 is 4mm, the height H1 of the supporting protrusion 12 protruding from the cover plate 10 is 6mm, the distance W0 between the supporting protrusion 12 and the edge of the cover plate 10 is 2mm, and the height difference between the supporting protrusion 12 and the pole post 21 protruding from the supporting surface 101 is H1-H=2.00mm.

[0081] According to the simulation analysis of PACK in accordance with national standards, when the battery pack is subjected to mechanical impact in the thickness direction of the cover plate 10, the stress at the position of the cell terminal 21 does not change significantly. In addition, 5 cells were randomly selected for safety testing, and no obvious fire or explosion problems were found, indicating that the force at the position of terminal 21 is not significant and terminal 21 has not undergone significant deformation.

[0082] Comparative Example 1 The total length L of the cover plate 10 is 100mm, the total width W of the cover plate 10 is 14mm, the distance L0 between the supporting protrusion 12 and the pole post 21 is 3.5mm, the total width W1 of the supporting protrusion 12 is 10mm, the height H of the pole post 21 protruding from the supporting surface 101 is 2mm, the height H1 of the supporting protrusion 12 protruding from the cover plate 10 is 2.8mm, the distance W0 between the supporting protrusion 12 and the edge of the cover plate 10 is 2mm, and the height difference between the supporting protrusion 12 and the pole post 21 protruding from the supporting surface 101 is H1-H=0.80mm.

[0083] According to the simulation analysis of PACK in accordance with national standards, when the battery pack is subjected to mechanical impact in the thickness direction of the cover plate 10, the internal stress of the material at the pole post 21 increases by about 5%, indicating that the height difference between the support protrusion 12 and the pole post 21 protruding from the support surface 101 is too small. After the external impact, the pole post 21 has been subjected to force and has undergone slight deformation.

[0084] Comparative Example 2 The total length L of the cover plate 10 is 130mm, the total width W of the cover plate 10 is 18mm, the distance L0 between the supporting protrusion 12 and the pole post 21 is 5mm, the total width W1 of the supporting protrusion 12 is 14mm, the height H of the pole post 21 protruding from the supporting surface 101 is 4mm, the height H1 of the supporting protrusion 12 protruding from the cover plate 10 is 6.4mm, the distance W0 between the supporting protrusion 12 and the edge of the cover plate 10 is 2mm, and the height difference between the supporting protrusion 12 and the pole post 21 protruding from the supporting surface 101 is H1-H=2.40mm.

[0085] According to the simulation analysis of PACK in accordance with national standards, when the battery pack is subjected to mechanical impact in the thickness direction of the cover plate 10, the stress at the position of the cell terminal 21 does not change significantly, but the height H1 of the support protrusion 12 protruding from the support surface 101 is too large, and the cell capacity is reduced.

[0086] Comparative Example 3 The total length L of the cover plate 10 is 180mm, the total width W of the cover plate 10 is 25mm, the distance L0 between the supporting protrusion 12 and the pole post 21 is 7mm, the total width W1 of the supporting protrusion 12 is 24mm, the height H of the pole post 21 protruding from the supporting surface 101 is 3.6mm, the height H1 of the supporting protrusion 12 protruding from the cover plate 10 is 5.5mm, the distance W0 between the supporting protrusion 12 and the edge of the cover plate 10 is 0.5mm, and the height difference between the supporting protrusion 12 and the pole post 21 protruding from the supporting surface 101 is H1-H=1.90mm.

[0087] Simulation analysis of the PACK according to national standards showed that when the battery pack was subjected to mechanical impact in the thickness direction of the cover plate 10, the stress at the cell terminal 21 position did not change significantly. However, the edge distance W0 of the supporting protrusion 12 was too small. After the cell pack was insulated, the folded-over cover plate width was small, resulting in the insulation film lifting problem. Based on the above test results, when a support protrusion 12 is added to the cover plate 10 and the support protrusion 12 meets the above design requirements, when the battery pack is subjected to mechanical impact force along the thickness direction of the cover plate 10 in the cell simulation analysis, the position of the pole post 21 does not undergo significant deformation, and the cell safety test is passed. When the height of the support protrusion 12 is insufficient, the pole post 21 undergoes slight deformation after the cell mechanical impact test. When the support protrusion 12 is too wide and the edge distance W0 is too small, the edge distance of the support protrusion 12 is too small, which will affect the yield of the outer insulation film.

[0088] The cover plate assembly provided by the present invention is described below. The cover plate assembly described below can be referred to in correspondence with the cell cover plate described above.

[0089] Reference Figures 1 to 4A cover plate assembly includes a battery cell cover plate, an electrode structure 20, and an insulating structure 30 provided in any of the above examples; wherein, the electrode structure 20 includes a pole post 21 and a connecting piece 22, the pole post 21 is disposed in a pole post hole 11, and the height H1 of the support protrusion 12 protruding from the support surface 101 and the height H of the pole post 21 protruding from the support surface 101 satisfy (H+1.0mm)≤H1≤(H+2.0mm); one end of the connecting piece 22 is connected to the pole post 21, and the other end is used to connect to the tab 51; the insulating structure 30 is disposed between the electrode structure 20 and the cover plate body 10 for electrical isolation between the electrode structure 20 and the cover plate body 10.

[0090] In detail, the insulation structure 30 includes a first insulating element 31, a second insulating element 32, and an insulating ring 33; wherein, the first insulating element 31 is pressed between the pole post 21 and the supporting surface 101 of the cover plate 10, the second insulating element 32 is pressed between the pole post 21 and another plate surface of the cover plate 10, and extends to the inner wall of the weld joint 102; the insulating ring 33 is sleeved on the outside of the pole post 21, passes through the pole post hole 11, and its two ends are respectively connected to the first insulating element 31 and the second insulating element 32, thereby separating the pole post 21 from the hole wall of the pole post hole 11.

[0091] To facilitate the connection between the tab 51 and the connecting piece 22, in one example of the present invention, the connecting piece 22 includes an integrally formed first part 221, a second part 222 and a third part 223. One end of the first part 221 is fixedly connected to the pole post 21, specifically including but not limited to riveting or welding, and the other end extends to the welding port 102. One end of the second part 222 is connected to the end of the first part 221 away from the connecting piece 22, and the other end passes through the welding port 102. One end of the third part 223 is connected to the end of the second part 222 away from the first part 221, and the other end extends along the length direction of the cover plate body 10. The second part 222 and the third part 223 are configured as a bent portion.

[0092] Furthermore, the height H2 of the second part 222 protruding from the support surface 101 satisfies: 0.8mm≤H2≤1.5mm. This design not only meets the requirements of flat bonding of the tab 51 and normal operation of welding tools, but also saves internal space of the battery cell and improves the utilization rate of internal space.

[0093] In the width direction of the cover plate 10, the electrode 51 is disposed on at least one side of the third part 223. Before welding the electrode 51 and the connecting piece 22, the lateral electrode 51 passes through the gap between the third part 223 and the welding port 102 and is bent so that the electrode 51 overlaps on the third part 223. Then the two are welded to realize the connection between the electrode 51 and the connecting piece 22.

[0094] The battery cell provided by the present invention is described below. The battery cell described below can be referred to in correspondence with the cover plate assembly described above.

[0095] Reference Figures 7 to 10 A battery cell includes a housing 40, a cell cover or cover assembly provided in any of the above examples, and an electrode assembly 50; wherein one end of the housing 40 is provided as an open opening; a cover body 10 is fixedly connected to the open opening of the housing 40; and the electrode assembly 50 is disposed in a cavity surrounded by the housing 40 and the cover body 10.

[0096] Furthermore, the welding port 102 corresponds to the position of the tab 51. The tab 51 extends out of the welding port 102 and is bent and overlapped on the third part 223 of the connecting piece 22. After the tab 51 and the third part 223 are welded, the welding port 102 is sealed by a sealing plate. The third part 223 with the tab 51 welded on is accommodated in the tab receiving cavity 121. The protruding part of the sealing plate protrudes from the support surface 101, thus forming the aforementioned support protrusion 12.

[0097] It is understood that, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of the different embodiments or examples.

[0098] With the battery cell cover, cover assembly and battery cell provided by the embodiments of the present invention, when the upper surface of the battery pack is subjected to an external impact, the impact force will be absorbed by the support protrusion 12, thereby avoiding direct force on the terminal post and reducing the risk of short circuit in the battery cell. At the same time, the impact force on the support protrusion 12 will be directly distributed to the cover body 10 and even the entire housing of the battery cell, thereby giving full play to the supporting performance of the battery cell housing, improving the mechanical strength of the entire pack and ensuring the long-term stable operation of the battery cell.

[0099] In addition to the above, the supporting protrusion 12 can also increase the heat dissipation area and can directly support the water cooling equipment in the Pack as a load-bearing component, so that the water cooling equipment in the Pack can directly act on the electrode area, thereby reducing the temperature of the electrode under battery charging and discharging conditions and improving the fast charging performance of the cell.

[0100] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A battery cell cover plate, characterized in that, include: The cover plate has two plates facing away from each other in its own thickness direction, and one of the plates is formed as a support surface; The pole hole penetrates the cover plate body; A support convex hull is provided protruding from the support surface, and the height H1 protruding from the support surface satisfies: (H+1.0mm)≤H1≤(H+2.0mm); where H is the height of the pole protruding from the support surface.

2. The cell cover plate according to claim 1, characterized in that, In the direction away from the support surface, the cross-sectional area of ​​the support protrusion gradually decreases along the direction perpendicular to the thickness of the cover plate.

3. The cell cover plate according to claim 2, characterized in that, The taper β of the supporting convex hull satisfies: 15°≤β≤25°.

4. The cell cover plate according to claim 1, characterized in that, The distance L0 between the supporting convex bulge and the pole post satisfies: 3mm ≤ L0 ≤ 8mm; and / or, In the width direction of the cover plate, the distance W0 between the supporting protrusion and the edge of the cover plate satisfies: 1mm ≤ W0 ≤ 3mm; and / or, The height H1 of the support bulge protruding from the support surface is: 2.5mm≤H1≤6mm.

5. The cell cover plate according to claim 4, characterized in that, The supporting bulge is symmetrical about the centerline of the short side of the cover plate body; The distance W0 between the supporting protrusion and the edge of the cover plate is: (W-W1) / 2; where W is the total width of the cover plate and W1 is the total width of the supporting protrusion.

6. The cell cover plate according to any one of claims 1 to 5, characterized in that, The cover plate is provided with a welding port corresponding to the position of the electrode lug; the welding port penetrates the cover plate. A sealing plate is fitted onto the weld joint. The side of the sealing plate facing the weld joint is recessed in a direction away from the weld joint to form a tab receiving cavity, and a protrusion is formed on the side facing away from the weld joint to form the support protrusion.

7. The cell cover plate according to claim 6, characterized in that, The wall of the electrode receiving cavity is covered with insulating components.

8. A cover plate assembly, characterized in that, include: The cell cover plate as described in any one of claims 1 to 7; The electrode structure includes an electrode post and a connecting piece; the electrode post passes through the electrode post hole, and the height H of the electrode post protruding from the support surface and the height H1 of the support bulge protruding from the support surface satisfy: (H+1.0mm)≤H1≤(H+2.0mm); one end of the connecting piece is connected to the electrode post, and the other end is used to connect to the electrode tab; An insulating structure is disposed between the electrode structure and the cover plate body for electrical isolation between the electrode structure and the cover plate body.

9. The cover plate assembly according to claim 8, characterized in that, The connecting piece includes: The first part has one end connected to the pole post and the other end extending to the welding joint; The second part is inserted through the welding joint and one end is connected to the end of the first part away from the pole post. The height H2 of the second part protruding from the support surface satisfies: 0.8mm≤H2≤1.5mm. The third part has one end connected to the end of the second part away from the first part, and the other end extends along the length of the cover plate body.

10. A battery cell, characterized in that, include: The housing component has an opening at one end; The cell cover plate as described in any one of claims 1 to 7 or the cover plate assembly as described in any one of claims 8 to 9, wherein the cover plate body is sealed to the opening; The electrode assembly is disposed within the cavity formed by the housing and the cover plate, and the electrode tabs of the electrode assembly are connected to the electrode posts.

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