Battery cell cover plate assembly, battery cell and battery pack

Abstract

The invention relates to the technical field of batteries, and discloses a battery cell cover plate assembly, a battery cell and a battery pack. The cover plate is provided with a pair of pole through holes arranged at intervals along the X direction, and the cover plate is provided with a first side surface and a second side surface opposite to each other along the Y direction; and along the Y direction, the width of the cover plate is W1, the distance between the pole through hole and the first side surface is W2, the distance between the pole through hole and the second side surface is W3, and (W1-W2-W3) / W1 is more than or equal to 0.15 and less than or equal to 2 / 3. According to the battery cell cover plate assembly disclosed by the invention, W1, W2 and W3 are limited in a proper range, so that the sealing performance of the sealing ring can be ensured, air leakage at the pole through hole is avoided, and the sealing effect is 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 rapid development of new energy batteries, the energy density, lifespan, and safety performance of battery cells are receiving increasing attention. As a key packaging component of the battery cell, the cell cover assembly performs multiple functions, including terminal fixing, internal sealing, and electrical insulation. The structural design of the cell cover assembly directly affects the mechanical strength, sealing reliability, and thermal runaway protection capabilities of the battery cell.

[0003] In existing battery cell cover assemblies, the cover is prone to arching and deformation due to internal pressure during production or testing, resulting in insufficient compression of the sealing ring and causing the risk of air leakage, leading to poor sealing performance. Summary of the Invention

[0004] This invention provides a cell cover assembly, a cell, and a battery pack to solve the problem that existing cell cover assemblies are prone to deformation, resulting in poor sealing performance.

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

[0006] The cover plate has a pair of pole through holes spaced apart along the X direction, and the cover plate has a first side and a second side opposite to each other along the Y direction. Along the Y direction, the width of the cover plate is W1, the distance between the pole through hole and the first side is W2, and the distance between the pole through hole and the second side is W3, satisfying 0.15≤(W1-W2-W3) / W1≤2 / 3.

[0007] Beneficial Effects: The battery cell cover assembly of the present invention controls (W1-W2-W3) / W1 within a suitable range, effectively balancing the width dimensions of the terminal hole and the cover plate. While ensuring sufficient space for the terminal to arrange the busbar welding trajectory, it also improves the bending resistance of the cover plate, effectively preventing the cover plate from arching upwards due to internal pressure during battery cell production or testing. This avoids insufficient compression of the sealing ring and the risk of leakage, thus significantly improving the sealing effect. If the value of (W1-W2-W3) / W1 is too large, the terminal will be relatively thick, the distance between the terminal and the first and second sides will be small, and the bending resistance of the cover plate will be poor. During battery cell production or testing, the cover plate is easily deformed upwards due to internal pressure, resulting in insufficient compression of the sealing ring and ultimately causing leakage.

[0008] In one alternative implementation, 10 mm ≤ W1-W2-W3 ≤ 40 mm, 5 mm ≤ W2 ≤ 20 mm, and 5 mm ≤ W3 ≤ 20 mm.

[0009] Beneficial effects: By controlling W1-W2-W3 and W2 and W3 within a suitable range, the through-hole of the electrode post has a sufficient diameter to accommodate electrode posts with larger diameters, thereby providing enough space for the busbar welding trajectory and enabling the electrode post and busbar to form a sufficient welding area. Furthermore, it ensures sufficient distance between the electrode post and the first and second sides of the cover plate, providing ample space for the first limiting part and sufficient adhesion area for the patch on the outer surface of the cover plate, preventing the patch from lifting and failing due to insufficient adhesion area.

[0010] In one alternative embodiment, the cover plate has a first surface and a second surface opposite each other along the Z direction. The second surface has a first groove formed around the periphery of the pole through hole, and a second groove is punched around the periphery of the first groove to form a rib extending along the Z direction between the first groove and the second groove. The cell cover assembly also includes: The pole includes a column portion passing through the through hole of the pole, and a first limiting portion is provided at one end of the column portion extending out of the first surface along the Z direction, and a second limiting portion is provided at least partially located in the first groove at one end of the column portion along the Z direction near the second surface. An upper insulating member is sleeved outside the column portion and sandwiched between the first surface and the first limiting portion; A sealing ring is fitted over the cylindrical part and sandwiched between the bottom of the first groove and the second limiting part.

[0011] Beneficial effects: The electrode post adopts a structure consisting of a column body, a first limiting part, and a second limiting part. The first limiting part and the first surface of the cover plate limit the upper insulating component, while the second limiting part and the first groove on the cover plate limit the sealing ring. Compared to traditional riveted cover plates, this simplifies the overall structure, eliminates the riveting process, and significantly reduces manufacturing costs. By creating a first and a second groove at intervals around the electrode post's through-hole on the second surface of the cover plate, and by setting the second groove to be stamped, a rib extending in the Z-direction is formed between the first and second grooves. This rib provides a rigid physical barrier to restrict the electrode post's rotation, thereby improving the electrode post's torsional resistance and preventing it from loosening.

[0012] In one optional embodiment, the cross-section of the column portion and the first limiting portion in the XY plane is circular, the cross-section of the second limiting portion in the XY plane is non-circular, a stepped surface is formed at the connection between the second limiting portion and the column portion, along the Z direction and in the direction from the first surface to the second surface, the bottom surface of the rib away from the second surface is located below the stepped surface, and the distance between the two is H1, satisfying 0.3 mm ≤ H1 ≤ 1 mm.

[0013] Beneficial effects: By setting the cross-section of the second limiting part to be non-circular, and with the bottom surface of the rib away from the second surface located below the stepped surface, the second limiting part can be rigidly supported by the rib, thereby effectively preventing the rotation of the second limiting part, that is, restricting the rotation of the entire electrode post, and exhibiting high torsional resistance. If H1 is too small, the rib will be difficult to effectively embed and block the rotation of the second limiting part, resulting in poor anti-torsional effect. If H1 is too large, the height of the electrode post will be excessively raised, resulting in an excessively thick second limiting part, occupying internal space of the cell and affecting energy density.

[0014] In one optional embodiment, the thickness of the cover plate along the Z direction is H2, and the distance between the bottom of the first groove and the first surface is H3, satisfying 0.8 mm ≤ H3 ≤ H2 - 0.5 mm and 1.3 mm ≤ H2 ≤ 3 mm.

[0015] Beneficial effects: By controlling H2 and H3 within a suitable range, it is possible to ensure that the thinned portion formed after the first groove is opened in the cover plate has sufficient strength. It also ensures that the first groove provides enough space to lift the entire pole post upwards, so that the stepped surface extends beyond the bottom of the rib away from the first surface, thereby using the rib to prevent the pole post from rotating. If H3 is too small, the thinned portion of the cover plate will lack strength and is prone to deformation under stress. If H3 is too large, the installation height of the pole post will be too high, and it will be difficult to form the rib through stamping.

[0016] In one alternative embodiment, along the Z direction, the groove depth of the second groove is H4, satisfying 0.3 mm ≤ H4 ≤ H2 / 2.

[0017] Beneficial effects: By controlling H4 within a suitable range, it is possible to ensure that ribs of a certain height are formed after stamping, and it is also possible to prevent the second groove from being too deep and weakening the overall strength of the cover plate.

[0018] In one alternative embodiment, the first limiting portion extends out of the pole post through hole by a length L1 along the X and / or Y directions, satisfying 0.5 mm ≤ L1 ≤ 5 mm.

[0019] Beneficial effects: If L1 is too small, the overlap area between the first limiting part and the upper insulating part will be too small, which will easily lead to large resistance fluctuations and insufficient strength.

[0020] In one optional embodiment, the thickness of the first limiting portion along the Z direction is H5, satisfying 0.5 mm ≤ H5 ≤ 2.5 mm.

[0021] Beneficial effects: If H5 is too small, the strength of the first limiting part will be insufficient. If H5 is too large, it will be difficult to fold and cracks will easily occur at the folding point.

[0022] In one optional embodiment, the upper insulating member includes a body portion and a protrusion portion connected along the Z direction. The body portion is sandwiched between the first limiting portion and the first surface. The protrusion portion is disposed around the side surface of the body portion away from the first surface. The protrusion portion surrounds the outer side of the first limiting portion along the XY direction. The height of the body portion along the Z direction is H6, satisfying 0.5 mm ≤ H6 ≤ 2 mm.

[0023] Beneficial effects: By configuring the upper insulating component as a body and a protrusion, and positioning the protrusion around the outside of the first limiting portion, a ring-shaped enclosure is formed around the first limiting portion. This allows the mechanical gripper to grasp the upper insulating component without directly impacting the first limiting portion and causing stringing. By controlling H6 within a suitable range, the risk of insulation failure due to excessively thin injection molding thickness is avoided, while also indirectly controlling the height of the electrode post and preventing it from becoming too high.

[0024] In one optional embodiment, along the Z direction, the side surface of the first limiting portion away from the first surface extends beyond the side surface of the protrusion away from the first surface by a distance L2, satisfying 0.2 mm ≤ L2 ≤ 1 mm.

[0025] Beneficial effects: If L2 is too small, the protrusion may get too close to or even higher than the first limiting part, causing the protrusion to press against the busbar during installation, resulting in poor soldering or contact between the first limiting part and the busbar. If L2 is too large, the first limiting part will be too high, and the robot arm may directly touch the first limiting part during gripping, resulting in inaccurate gripping position or wire pulling.

[0026] Secondly, the present invention also provides a battery cell, comprising: The housing has an opening at at least one end; An electrode assembly is disposed within the housing, and an electrode tab is provided at one end of the electrode assembly near the opening; The aforementioned cell cover assembly has the cover plate placed over the opening and connected to the housing.

[0027] Beneficial Effects: The battery cell of this invention controls (W1-W2-W3) / W1 within a suitable range, effectively balancing the width dimensions of the terminal hole and the cover plate. This ensures sufficient space for the terminal to arrange the busbar welding trajectory while also improving the bending resistance of the cover plate. This effectively prevents the cover plate from arching upwards due to internal pressure during battery cell production or testing, avoiding insufficient compression of the sealing ring and the risk of leakage, thus significantly improving the sealing effect. If the value of (W1-W2-W3) / W1 is too large, the terminal will be relatively thick, the distance between the terminal and the first and second sides will be small, and the bending resistance of the cover plate will be poor. During battery cell production or testing, the cover plate is easily deformed upwards due to internal pressure, leading to insufficient compression of the sealing ring and ultimately causing leakage.

[0028] Thirdly, the present invention also provides a battery pack comprising: at least one of the above-described battery cells.

[0029] Beneficial effects: Since the battery pack includes battery cells, it has the same effects as the battery cells, which will not be repeated here. Attached Figure Description

[0030] 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.

[0031] Figure 1 This is a schematic diagram of the structure of the first type of battery cell cover assembly according to an embodiment of the present invention; Figure 2 This is an exploded view of the first type of battery cell cover assembly according to an embodiment of the present invention; Figure 3 This is a top view of the cover plate of the first type of battery cell cover plate assembly according to an embodiment of the present invention; Figure 4 This is a partial bottom view of the cover plate of the first type of battery cell cover plate assembly according to an embodiment of the present invention; Figure 5 This is a cross-sectional view of the cover plate of the first type of battery cell cover plate assembly according to an embodiment of the present invention; Figure 6 This is a top view of the first type of battery cell cover assembly according to an embodiment of the present invention; Figure 7 for Figure 6 Sectional view at point AA; Figure 8 for Figure 7 A magnified view of a portion of the image; Figure 9This is a schematic diagram of the structure of the second type of battery cell cover assembly according to an embodiment of the present invention; Figure 10 This is an exploded view of the second type of battery cell cover assembly according to an embodiment of the present invention; Figure 11 This is a schematic diagram of the structure of the third type of battery cell cover assembly according to an embodiment of the present invention; Figure 12 This is a top view of the third type of battery cell cover assembly according to an embodiment of the present invention; Figure 13 for Figure 12 A partial schematic diagram of the middle BB section; Figure 14 This is a schematic diagram of the structure of the fourth type of battery cell cover assembly according to an embodiment of the present invention; Figure 15 This is a top view of the fourth type of battery cell cover assembly according to an embodiment of the present invention; Figure 16 for Figure 15 A partial schematic diagram at point CC.

[0032] Explanation of reference numerals in the attached figures: 1. Cover plate; 101. First surface; 102. Second surface; 103. Through hole of pole post; 104. First groove; 105. Second groove; 106. Rib; 107. First side; 108. Second side; 2. Pole post; 201. Post body; 202. First limiting part; 203. Second limiting part; 204. Step surface; 205. First post body; 206. Second post body; 207. Base plate; 3. Upper insulating component; 301. Body part; 302. Protrusion; 4. Sealing ring; 5. Lower insulating component; 6. Welding ring; 7. Riveting block. Detailed Implementation

[0033] 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.

[0034] In the description of the embodiments of the present invention, the technical terms "first", "second", etc. are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0035] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0036] The battery cell mentioned in this embodiment of the invention is the smallest unit that makes up a battery, and it can independently perform the functions of charging and discharging. This embodiment of the invention does not impose any particular limitations on the type or shape of the battery cell; it can be a blade cell, a prismatic cell, or other types of battery cells. The battery cell in this embodiment of the invention can be a lithium-ion cell, a potassium-ion cell, a sodium-ion cell, a lithium-sulfur cell, etc., with lithium-ion cells being particularly preferred.

[0037] A battery cell typically includes an electrode assembly, also known as an electrode group. The electrode group consists of a positive electrode, a negative electrode, and an insulating component. During the charging and discharging process of the battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The insulating component, positioned between the positive and negative electrodes, prevents short circuits while allowing active ions to pass through.

[0038] The battery cell also includes a casing and a cover plate. The casing and cover plate together form a space for encapsulating the electrode assembly. The casing can be made of steel, aluminum, or composite metal (such as a copper-aluminum composite casing). The cover plate can also integrate and install components such as terminals and plastic insulation parts. The terminals are used to lead out the current from the electrode assembly, and the terminals are welded and fixed to the electrode lugs of the electrode assembly to achieve electrical connection.

[0039] The existing battery cell cover structure is prone to deformation during production or testing due to internal pressure, resulting in insufficient compression of the sealing ring and the risk of air leakage. Therefore, the sealing effect is poor.

[0040] Furthermore, existing battery cell cover structures are mainly divided into three categories: riveted covers, injection-molded covers, and composite covers of injection molding and welding. Riveted covers mechanically lock the electrode post to the cover plate using riveting blocks, resulting in high connection strength and good torsional resistance. However, they are costly to manufacture, and the riveting process can easily cause stress damage to the cover plate substrate, hindering lightweighting and cost control. Injection-molded covers use injection molding to integrally encapsulate the electrode post, sealing ring, and cover plate, offering advantages such as simple process and low cost. However, the electrode post has a weak ability to withstand axial thrust and circumferential torque, making it prone to loosening and seal failure under long-term use or vibration conditions, thus affecting the battery cell's cycle life. Composite covers of injection molding and welding form a preliminary seal through injection molding, supplemented by laser welding reinforcement. While this improves connection strength to some extent, problems remain, such as the electrode post sealing interface being susceptible to welding heat and insufficient airtightness after the sealing ring ages.

[0041] Therefore, there is still the problem of not being able to simultaneously achieve low cost, high torsional strength, and high sealing performance.

[0042] The following is combined with Figures 1 to 16 The following describes embodiments of the present invention.

[0043] According to an embodiment of the present invention, in one aspect, such as Figure 1 and Figure 2 As shown, a cell cover assembly is provided, which mainly includes: cover 1.

[0044] like Figure 3 As shown, the cover plate 1 has a pair of pole through holes 103 spaced apart along the X direction, and the cover plate 1 has a first side 107 and a second side 108 opposite to each other along the Y direction.

[0045] Along the Y direction, the width of the cover plate 1 is W1 (mm), the distance between the pole through hole 103 and the first side 107 is W2 (mm), and the distance between the pole through hole 103 and the second side 108 is W3 (mm), satisfying 0.15≤(W1-W2-W3) / W1≤2 / 3.

[0046] Therefore, the battery cell cover assembly provided in this embodiment of the invention controls (W1-W2-W3) / W1 within a suitable range, effectively balancing the width dimensions of the terminal through hole 103 and the cover plate 1. While ensuring that the terminal 2 has sufficient space to arrange the busbar welding trajectory, it also improves the bending resistance of the cover plate 1, effectively preventing the cover plate 1 from arching and deforming upwards due to internal pressure during the production or testing of the battery cell. This avoids the risk of insufficient compression of the sealing ring 4 and air leakage, thereby significantly improving the sealing effect.

[0047] If the value of (W1-W2-W3) / W1 is too large, the pole post 2 will be relatively thick, the distance between the pole post 2 and the first side 107 and the second side 108 will be small, the bending resistance of the cover plate 1 will be poor, and during the production or testing of the battery cell, the cover plate 1 will be easily affected by the internal pressure and deform upward, resulting in insufficient compression of the sealing ring 4 and ultimately causing air leakage.

[0048] Specifically, the Z direction is the thickness direction of cover plate 1, that is, the vertical direction, such as... Figure 1 As indicated by arrow Z in the diagram, the X direction is also the length direction of cover plate 1, as shown in the diagram. Figure 1 As shown by arrow X in the diagram, the Y direction is also the width direction of cover plate 1, as shown in the diagram. Figure 1 As indicated by the arrow Y in the diagram.

[0049] In one embodiment, 10 mm ≤ W1-W2-W3 ≤ 40 mm, 5 mm ≤ W2 ≤ 20 mm, and 5 mm ≤ W3 ≤ 20 mm.

[0050] By controlling W1-W2-W3 and W2 and W3 within a suitable range, it is ensured that the through hole 103 of the pole post has a sufficient diameter to accommodate the larger diameter pole post 2, thereby providing a sufficiently large space for the busbar welding trajectory and enabling the pole post 2 and the busbar to form a sufficient welding area. Furthermore, it ensures that there is sufficient distance between the pole post 2 and the first side 107 and the second side 108 of the cover plate 1, providing sufficient arrangement space for the first limiting part 202 and also providing sufficient adhesion area for the patch on the outer surface of the cover plate 1, preventing the patch from lifting and failing due to insufficient adhesion area.

[0051] Furthermore, in one embodiment, W2=W3, and the distances between the pole post 2 and the first side 107 and the second side 108 of the cover plate 1 are equal, so as to distribute the force evenly.

[0052] It should be noted that the embodiments of the present invention do not limit the specific structure of the battery cell cover assembly. Any existing structural type can be selected as needed. For example, a riveted cover structure, an injection-molded cover structure, or a minimalist cover structure can be used.

[0053] In one embodiment, such as Figures 1 to 5 As shown, the cell cover assembly adopts a minimalist cover structure.

[0054] Specifically, the cover plate 1 has a first surface 101 and a second surface 102 opposite to each other along the Z direction. The second surface 102 has a first groove 104 formed around the periphery of the pole post through hole 103, and a second groove 105 is punched around the periphery of the first groove 104 to form a rib 106 extending along the Z direction between the first groove 104 and the second groove 105.

[0055] like Figure 1 and Figure 2 As shown, the cell cover assembly also includes: pole post 2, upper insulating component 3, and sealing ring 4.

[0056] The pole post 2 includes a column portion 201 that passes through the pole post through hole 103. One end of the column portion 201 extending out of the first surface 101 along the Z direction is provided with a first limiting portion 202. The end of the column portion 201 near the second surface 102 along the Z direction is provided with a second limiting portion 203 that is at least partially located in the first groove 104.

[0057] The upper insulating component 3 is sleeved outside the column part 201 and sandwiched between the first surface 101 and the first limiting part 202.

[0058] The sealing ring 4 is sleeved on the outside of the column part 201 and sandwiched between the bottom of the first groove 104 and the second limiting part 203.

[0059] The pole post 2 adopts a structure consisting of a column part 201, a first limiting part 202, and a second limiting part 203. The first limiting part 202 and the first surface 101 of the cover plate 1 limit the upper insulating member 3, and the second limiting part 203 and the first groove 104 on the cover plate 1 limit the sealing ring 4. Compared with the traditional riveted cover plate, this simplifies the overall structure, eliminates the riveting process, and significantly reduces manufacturing costs. By opening the first groove 104 and the second groove 105 at intervals around the periphery of the pole post through hole 103 on the second surface 102 of the cover plate 1, and setting the second groove 105 to be stamped, a rib 106 extending in the Z direction is formed between the first groove 104 and the second groove 105. This rib 106 provides a rigid physical barrier to restrict the rotation of the pole post 2, thereby improving the torsional resistance of the pole post 2 and preventing the pole post 2 from loosening.

[0060] Specifically, after the cover plate 1 is assembled with the housing, the first surface 101 is the end face away from the electrode group, and the second surface 102 is the end face close to the electrode group. The first limiting part 202, the column part 201 and the second limiting part 203 can be integrally formed, wherein the first limiting part 202 is formed by stamping and folding for assembly.

[0061] Furthermore, such as Figure 1 and Figure 2 As shown, the cell cover assembly also includes a lower insulating member 5, which is attached to the second surface 102 of the cover 1 for insulation between the cover 1 and the electrode group.

[0062] In one embodiment, such as Figure 2 and Figure 8 As shown, the cross-section of the column portion 201 and the first limiting portion 202 in the XY plane is circular, while the cross-section of the second limiting portion 203 in the XY plane is non-circular. A stepped surface 204 is formed at the connection between the second limiting portion 203 and the column portion 201, along the Z direction and pointing from the first surface 101 to the second surface 102. The bottom surface of the rib 106 away from the second surface 102 is located below the stepped surface 204, and the distance between the two is H1, which satisfies 0.3 mm ≤ H1 ≤ 1 mm.

[0063] The cross-section of the second limiting part 203 is set to be non-circular, and the bottom surface of the rib 106, away from the second surface 102, is located below the stepped surface 204. This allows the second limiting part 203 to be rigidly supported by the rib 106, thereby effectively preventing the second limiting part 203 from rotating, that is, restricting the overall rotation of the pole post 2, and providing high torsional resistance. If H1 is too small, the rib 106 will have difficulty effectively embedding and blocking the rotation of the second limiting part 203, resulting in poor anti-torsional effect. If H1 is too large, the height of the pole post 2 will be excessively raised, resulting in an excessively thick second limiting part 203, occupying the internal space of the cell and affecting the energy density.

[0064] It should be noted that the embodiments of the present invention do not restrict the specific shape of the cross-section of the second limiting part 203. Regular shapes such as rectangles and ellipses can be selected as needed, or irregular shapes can be used.

[0065] Furthermore, in one embodiment, such as Figure 8 As shown, along the Z direction, the thickness of the cover plate 1 is H2, and the distance between the bottom of the first groove 104 and the first surface 101 is H3, satisfying 0.8 mm≤H3≤H2-0.5 mm and 1.3 mm≤H2≤3 mm.

[0066] By controlling H2 and H3 within a suitable range, it can be ensured that the thinned portion formed after the first groove 104 is opened in the cover plate 1 has sufficient strength. It can also be ensured that the first groove 104 provides enough space to lift the pole post 2 upwards as a whole, so that the stepped surface 204 extends beyond the bottom of the rib 106 away from the first surface 101, thereby using the rib 106 to prevent the pole post 2 from rotating. If H3 is too small, the thinned portion of the cover plate 1 will lack strength and will easily deform under stress. If H3 is too large, the installation height of the pole post 2 will be too high, and it will be difficult to form the rib 106 through a stamping process.

[0067] For example, in an embodiment of the present invention, the value of H2 can be any value among 1.3 mm, 2 mm, 3 mm or any value between any two values, and the corresponding value of H3 can be any value among 0.8 mm, 1 mm, 2.5 mm or any value between any two values.

[0068] Furthermore, in one embodiment, such as Figure 8 As shown, along the Z direction, the groove depth of the second groove 105 is H4, satisfying 0.3 mm ≤ H4 ≤ H2 / 2. By controlling H4 within a suitable range, it is possible to ensure that a certain height of rib 106 is formed after stamping, and it is also possible to prevent the second groove 105 from being too deep and weakening the overall strength of the cover plate 1.

[0069] For example, in an embodiment of the present invention, the value of H4 can be any value among 0.3 mm, 0.5 mm, 0.7 mm, 1 mm, and 1.5 mm, or a value between any two values.

[0070] In one embodiment, such as Figure 8 As shown, along the X and / or Y directions, the first limiting part 202 extends out of the pole post through hole 103 for a length of L1, satisfying 0.5 mm ≤ L1 ≤ 5 mm. If L1 is too small, the overlap area between the first limiting part 202 and the upper insulating member 3 will be too small, which will easily lead to large resistance fluctuations and insufficient strength.

[0071] For example, in an embodiment of the present invention, the value of L1 can be any value among 0.5 mm, 1 mm, 1.5 mm, 2 mm, 3 mm, 4 mm, and 5 mm, or a value between any two values.

[0072] In one embodiment, such as Figure 8 As shown, the thickness of the first limiting part 202 along the Z direction is H5, satisfying 0.5 mm ≤ H5 ≤ 2.5 mm. If H5 is too small, the strength of the first limiting part 202 will be insufficient. If H5 is too large, it will be difficult to fold and cracks will easily occur at the folding point.

[0073] For example, in an embodiment of the present invention, the value of H5 can be any value among 0.5 mm, 1 mm, 1.5 mm, 2 mm, and 2.5 mm, or a value between any two values.

[0074] In one embodiment, such as Figure 2 and Figure 8 As shown, the upper insulating member 3 includes a body portion 301 and a protrusion 302 connected along the Z direction. The body portion 301 is sandwiched between the first limiting portion 202 and the first surface 101. The protrusion 302 is disposed around the side surface of the body portion 301 away from the first surface 101. The protrusion 302 surrounds the outer side of the first limiting portion 202 along the XY direction. The height of the body portion 301 along the Z direction is H6, which satisfies 0.5 mm ≤ H6 ≤ 2 mm.

[0075] In the production process of the cell cover assembly, for ease of handling, a mechanical gripper is typically used to grasp the outer periphery of the protrusion 302 of the upper insulating member 3. The upper insulating member 3 is configured with a body part 301 and a protrusion 302, with the protrusion 302 surrounding the outside of the first limiting part 202, forming a ring around the first limiting part 202. This allows the mechanical gripper to grasp the upper insulating member 3 without directly impacting the first limiting part 202 and causing stringing. By controlling H6 within a suitable range, the risk of insulation failure due to excessively thin injection molding is avoided, and the height of the electrode post 2 is indirectly controlled, preventing it from becoming too high.

[0076] For example, in an embodiment of the present invention, the value of H6 can be any value among 0.5 mm, 1 mm, 1.5 mm, 2 mm, or a value between any two values.

[0077] In one embodiment, such as Figure 8 As shown, along the Z direction, the side surface of the first limiting part 202 away from the first surface 101 extends beyond the side surface of the protrusion 302 away from the first surface 101 by a distance of L2, satisfying 0.2 mm ≤ L2 ≤ 1 mm.

[0078] If L2 is too small, the protrusion 302 may get too close to or even higher than the first limiting part 202, causing the protrusion 302 to press against the busbar during installation, resulting in poor soldering or contact between the first limiting part 202 and the busbar. If L2 is too large, the first limiting part 202 will be too high, and the robot arm may directly touch the first limiting part 202 during gripping, resulting in inaccurate gripping position or wire pulling.

[0079] For example, in an embodiment of the present invention, the value of L2 can be any value among 0.2 mm, 0.5 mm, 0.7 mm, 0.9 mm, 1 mm, or a value between any two values.

[0080] In some other embodiments, such as Figure 9 and Figure 10 As shown, the cell cover assembly can also be other forms of minimalist cover structure.

[0081] Specifically, the cell cover assembly also includes: a terminal post 2, an upper insulating component 3, a sealing ring 4, a lower insulating component, and a welding ring 6. The upper insulating component 3 is fitted over the terminal post 2, and the welding ring 6 is fitted over the upper insulating component 3, with the inner circumference of the welding ring 6 engaging with the outer circumference of the upper insulating component 3. This engagement can be achieved using a slot or snap-fit ​​mechanism. The outer circumference of the welding ring 6 is welded to the cover plate 1. The sealing ring 4 is fitted over the terminal post 2 and sandwiched between the terminal post 2 and the cover plate 1. The lower insulating component 5 is attached to the second surface 102 of the cover plate 1 for insulation between the cover plate 1 and the electrode assembly.

[0082] In some other embodiments, such as Figure 11 , Figure 12 and Figure 13 As shown, the cell cover assembly can also be a riveted cover structure.

[0083] Specifically, the cover plate 1 has a first surface 101 and a second surface 102 opposite to each other along the Z direction. The cell cover plate assembly also includes a pole post 2, an upper insulating member 3, a sealing ring 4, a lower insulating member 5, and a riveting block 7. The pole post 2 includes a first column portion 205, a second column portion 206, and a base plate 207 connected along the Z direction. The riveting block 7 is sleeved on the first column portion 205 and riveted to it. The upper insulating member 3 is sandwiched between the riveting block 7 and the cover plate 1. The sealing ring 4 is sleeved on the second column portion 206 and sandwiched between the pole post 2 and the cover plate 1. The lower insulating member 5 is attached to the second surface 102 of the cover plate 1 for insulation between the cover plate 1 and the electrode assembly. The portion of the lower insulating member 5 corresponding to the through hole 103 of the pole post is sandwiched between the cover plate 1 and the base plate 207.

[0084] In some other embodiments, such as Figure 14 , Figure 15 and Figure 16 As shown, the cell cover assembly can also be an injection-molded cover structure.

[0085] Specifically, the cover plate 1 has a first surface 101 and a second surface 102 opposite to each other along the Z direction. The cell cover plate assembly also includes a terminal post 2, an upper insulating member 3, a sealing ring 4, and a lower insulating member. The terminal post 2 includes a column portion 201 and a base plate 207 connected along the Z direction. The upper insulating member 3 is injection molded outside the column portion 201 and partially extends between the terminal post through hole 103 and the column portion 201. The sealing ring 4 is sleeved outside the column portion 201 and sandwiched between the terminal post 2 and the cover plate 1. The lower insulating member 5 is attached to the second surface 102 of the cover plate 1 for insulation between the cover plate 1 and the electrode assembly. The portion of the lower insulating member 5 corresponding to the terminal post through hole 103 is sandwiched between the cover plate 1 and the base plate 207.

[0086] Of course, in other embodiments, the cell cover assembly can also have other structural forms. The specific settings can be selected according to actual needs, and the embodiments of the present invention will not be described in detail here.

[0087] The following detailed description of the battery cell of the present invention, in conjunction with specific embodiments, is intended to limit the scope of protection claimed by the present invention.

[0088] In the following embodiments and comparative examples, the cell cover assembly adopts a minimalist cover structure, including: a cover plate 1, a terminal post 2, an upper insulating member 3, and a sealing ring 4. The cover plate 1 has a first surface 101 and a second surface 102 opposite to each other along the Z direction. The cover plate 1 is provided with a pair of terminal post through holes 103 spaced apart along the X direction. The second surface 102 has a first groove 104 formed around the periphery of the terminal post through holes 103, and a second groove 105 is punched around the periphery of the first groove 104 to form a rib 106 extending along the Z direction between the first groove 104 and the second groove 105. The terminal post 2 includes a column portion 201 passing through the terminal post through hole 103. One end of the column portion 201 extending along the Z direction from the first surface 101 is provided with a first limiting portion 202, and the end of the column portion 201 near the second surface 102 along the Z direction is provided with a second limiting portion 203 at least partially located within the first groove 104. The upper insulating member 3 is sleeved outside the column portion 201 and sandwiched between the first surface 101 and the first limiting portion 202. The sealing ring 4 is sleeved outside the column portion 201 and sandwiched between the bottom of the first groove 104 and the second limiting portion 203. The cover plate 1 has opposing first side surface 107 and second side surface 108 along the Y direction.

[0089] The cross-section of the column portion 201 and the first limiting portion 202 in the XY plane is circular, and the cross-section of the second limiting portion 203 in the XY plane is rectangular. A stepped surface 204 is formed at the connection between the second limiting portion 203 and the column portion 201. The step surface 204 is located along the Z direction and from the first surface 101 to the second surface 102. The bottom surface of the rib 106 away from the second surface 102 is located below the stepped surface 204.

[0090] Example 1: Along the Y direction, the width W1 of the cover plate 1 is 30 mm, the distance W2 between the electrode through hole 103 and the first side 107 is 5 mm, and the distance W3 between the electrode through hole 103 and the second side 108 is 5 mm. Therefore, (W1-W2-W3) / W1 is 2 / 3. After assembling the cell cover plate assembly into a cell, the cell is subjected to appearance and airtightness tests. The test results are shown in Table 1.

[0091] Example 2: Along the Y direction, the width W1 of the cover plate 1 is 30 mm, the distance W2 between the electrode through hole 103 and the first side 107 is 6 mm, and the distance W3 between the electrode through hole 103 and the second side 108 is 6 mm. Therefore, (W1-W2-W3) / W1 is 0.6. After assembling the cell cover plate assembly into a cell, the cell is subjected to appearance and airtightness tests. The test results are shown in Table 1.

[0092] Example 3: Along the Y direction, the width W1 of the cover plate 1 is 40 mm, the distance W2 between the electrode through hole 103 and the first side 107 is 8 mm, and the distance W3 between the electrode through hole 103 and the second side 108 is 8 mm. Therefore, (W1-W2-W3) / W1 is 0.6. After assembling the cell cover plate assembly into a cell, the cell is subjected to appearance and airtightness tests. The test results are shown in Table 1.

[0093] Example 4: Along the Y direction, the width W1 of the cover plate 1 is 40 mm, the distance W2 between the electrode through hole 103 and the first side 107 is 10 mm, and the distance W3 between the electrode through hole 103 and the second side 108 is 10 mm. Therefore, (W1-W2-W3) / W1 is 0.5. After assembling the cell cover plate assembly into a cell, the cell is subjected to appearance and airtightness tests. The test results are shown in Table 1.

[0094] Example 5: Along the Y direction, the width W1 of the cover plate 1 is 50 mm, the distance W2 between the electrode through hole 103 and the first side 107 is 12 mm, and the distance W3 between the electrode through hole 103 and the second side 108 is 12 mm. Therefore, (W1-W2-W3) / W1 is 0.52. After assembling the cell cover plate assembly into a cell, the cell is subjected to appearance and airtightness tests. The test results are shown in Table 1.

[0095] Example 6: Along the Y direction, the width W1 of the cover plate 1 is 50 mm, the distance W2 between the electrode through hole 103 and the first side 107 is 15 mm, and the distance W3 between the electrode through hole 103 and the second side 108 is 15 mm. Therefore, (W1-W2-W3) / W1 is 0.4. After assembling the cell cover plate assembly into a cell, the cell is subjected to appearance and airtightness tests. The test results are shown in Table 1.

[0096] Example 7: Along the Y direction, the width W1 of the cover plate 1 is 70 mm, the distance W2 between the electrode through hole 103 and the first side 107 is 17 mm, and the distance W3 between the electrode through hole 103 and the second side 108 is 17 mm. Therefore, (W1-W2-W3) / W1 is 18 / 35. After assembling the cell cover plate assembly into a cell, the cell is subjected to appearance and airtightness tests. The test results are shown in Table 1.

[0097] Example 8: Along the Y direction, the width W1 of the cover plate 1 is 70 mm, the distance W2 between the electrode through hole 103 and the first side 107 is 20 mm, and the distance W3 between the electrode through hole 103 and the second side 108 is 20 mm. Therefore, (W1-W2-W3) / W1 is 3 / 7. After assembling the cell cover plate assembly into a cell, the cell is subjected to appearance and airtightness tests. The test results are shown in Table 1.

[0098] Example 9: Along the Y direction, the width W1 of the cover plate 1 is 20 mm, the distance W2 between the electrode through hole 103 and the first side 107 is 7 mm, and the distance W3 between the electrode through hole 103 and the second side 108 is 7 mm. Therefore, (W1-W2-W3) / W1 is 0.3. After assembling the cell cover plate assembly into a cell, the cell is subjected to appearance and airtightness tests. The test results are shown in Table 1.

[0099] Example 10: Along the Y direction, the width W1 of the cover plate 1 is 80 mm, the distance W2 between the electrode through hole 103 and the first side 107 is 20 mm, and the distance W3 between the electrode through hole 103 and the second side 108 is 20 mm. Therefore, (W1-W2-W3) / W1 is 0.5. After assembling the cell cover plate assembly into a cell, the cell is subjected to appearance and airtightness tests. The test results are shown in Table 1.

[0100] Example 11: Along the Y direction, the width W1 of the cover plate 1 is 40 mm, the distance W2 between the electrode through hole 103 and the first side 107 is 17 mm, and the distance W3 between the electrode through hole 103 and the second side 108 is 17 mm. Therefore, (W1-W2-W3) / W1 is 0.15. After assembling the cell cover plate assembly into a cell, the cell is subjected to appearance and airtightness tests. The test results are shown in Table 1.

[0101] Comparative Example 1: Along the Y direction, the width W1 of the cover plate 1 is 30 mm, the distance W2 between the electrode through hole 103 and the first side 107 is 4 mm, and the distance W3 between the electrode through hole 103 and the second side 108 is 4 mm. Therefore, (W1-W2-W3) / W1 is 11 / 15, which is greater than 2 / 3. After assembling the cell cover plate assembly into a cell, the cell is subjected to appearance and airtightness tests. The test results are shown in Table 1.

[0102] Comparative Example 2: Along the Y direction, the width W1 of the cover plate 1 is 40 mm, the distance W2 between the electrode through hole 103 and the first side 107 is 6 mm, and the distance W3 between the electrode through hole 103 and the second side 108 is 6 mm. Therefore, (W1-W2-W3) / W1 is 0.7, which is greater than 2 / 3. After assembling the cell cover plate assembly into a cell, the cell is subjected to appearance and airtightness tests. The test results are shown in Table 1.

[0103] Comparative Example 3: Along the Y direction, the width W1 of the cover plate 1 is 50 mm, the distance W2 between the electrode through hole 103 and the first side 107 is 8 mm, and the distance W3 between the electrode through hole 103 and the second side 108 is 8 mm. Therefore, (W1-W2-W3) / W1 is 0.68, which is greater than 2 / 3. After assembling the cell cover plate assembly into a cell, the cell is subjected to appearance and airtightness tests. The test results are shown in Table 1.

[0104] Comparative Example 4: Along the Y direction, the width W1 of the cover plate 1 is 70 mm, the distance W2 between the electrode through hole 103 and the first side 107 is 10 mm, and the distance W3 between the electrode through hole 103 and the second side 108 is 10 mm. Therefore, (W1-W2-W3) / W1 is 5 / 7, which is greater than 2 / 3. After assembling the cell cover plate assembly into a cell, the cell is subjected to appearance and airtightness tests. The test results are shown in Table 1.

[0105] Table 1: Test Results

[0106] As can be seen from Table 1, in Examples 1 to 11, the following conditions are met: 0.15≤(W1-W2-W3) / W1≤2 / 3, 10mm≤W1-W2-W3≤40 mm, 5 mm≤W2≤20 mm, and 5 mm≤W3≤20 mm. Therefore, the appearance and airtightness tests can be passed, that is, the cover plate 1 does not show obvious deformation and has good airtightness.

[0107] In Comparative Examples 1 to 4, the value of (W1-W2-W3) / W1 is greater than 2 / 3, the pole post 2 is relatively thick, the distance between the pole post 2 and the first side 107 and the second side 108 is small, the bending resistance of the cover plate 1 is poor, and after the cover plate 1 is assembled into a battery cell, it bulges upward and deforms significantly due to the internal pressure, resulting in insufficient compression of the sealing ring 4 and a defect of poor airtightness.

[0108] It should be noted that the appearance test was conducted using a CCD camera, and the airtightness test was conducted using a helium detector, with a testing standard of <1.0×10⁻⁶. -7 Pa·m 3 / s.

[0109] According to an embodiment of the present invention, another aspect provides a battery cell, mainly comprising: a housing, an electrode assembly, and a battery cell cover assembly. The housing has an opening at at least one end. The electrode assembly is disposed within the housing, and a tab is provided at the end of the electrode assembly near the opening. A cover plate 1 is placed over the opening and connected to the housing, and a terminal post 2 is connected to the tab.

[0110] The battery cell provided in this embodiment of the invention controls (W1-W2-W3) / W1 within a suitable range, effectively balancing the width dimensions of the terminal through hole 103 and the cover plate 1. While ensuring that the terminal 2 has sufficient space to arrange the busbar welding trajectory, it also improves the bending resistance of the cover plate 1, effectively preventing the cover plate 1 from arching and deforming upwards due to internal pressure during the production or testing of the battery cell. This avoids the risk of insufficient compression of the sealing ring 4 and air leakage, thereby significantly improving the sealing effect.

[0111] If the value of (W1-W2-W3) / W1 is too large, the pole post 2 will be relatively thick, the distance between the pole post 2 and the first side 107 and the second side 108 will be small, the bending resistance of the cover plate 1 will be poor, and during the production or testing of the battery cell, the cover plate 1 will be easily affected by the internal pressure and deform upward, resulting in insufficient compression of the sealing ring 4 and ultimately causing air leakage.

[0112] According to an embodiment of the present invention, in another aspect, a battery pack is also provided, comprising: at least one of the above-described battery cells.

[0113] Since the battery pack includes battery cells and has the same effect as the battery cells, it will not be elaborated on here.

[0114] 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 such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A cell cover assembly, characterized in that, include: The cover plate has a pair of pole through holes spaced apart along the X direction, and the cover plate has a first side and a second side opposite to each other along the Y direction. Along the Y direction, the width of the cover plate is W1, the distance between the pole through hole and the first side is W2, and the distance between the pole through hole and the second side is W3, satisfying 0.15≤(W1-W2-W3) / W1≤2 / 3.

2. The cell cover assembly according to claim 1, characterized in that, 10 mm≤W1-W2-W3≤40 mm, 5 mm≤W2≤20 mm, 5 mm≤W3≤20 mm.

3. The cell cover assembly according to claim 1, characterized in that, The cover plate has a first surface and a second surface opposite each other along the Z direction. The second surface has a first groove formed around the periphery of the pole post through hole, and a second groove is punched around the periphery of the first groove to form a rib extending along the Z direction between the first groove and the second groove. The cell cover assembly also includes: The pole includes a column portion passing through the through hole of the pole, and a first limiting portion is provided at one end of the column portion extending out of the first surface along the Z direction, and a second limiting portion is provided at least partially located in the first groove at one end of the column portion along the Z direction near the second surface. An upper insulating member is sleeved outside the column portion and sandwiched between the first surface and the first limiting portion; A sealing ring is fitted over the cylindrical part and sandwiched between the bottom of the first groove and the second limiting part.

4. The cell cover assembly according to claim 3, characterized in that, The cross-section of the column portion and the first limiting portion in the XY plane is circular, while the cross-section of the second limiting portion in the XY plane is non-circular. A stepped surface is formed at the connection between the second limiting portion and the column portion. Along the Z direction and in the direction from the first surface to the second surface, the bottom surface of the rib away from the second surface is located below the stepped surface, and the distance between the two is H1, which satisfies 0.3mm≤H1≤1 mm.

5. The cell cover assembly according to claim 3, characterized in that, Along the Z direction, the thickness of the cover plate is H2, and the distance between the bottom of the first groove and the first surface is H3, satisfying 0.8 mm ≤ H3 ≤ H2 - 0.5 mm, 1.3 mm ≤ H2 ≤ 3 mm; And / or, along the Z direction, the groove depth of the second groove is H4, satisfying 0.3 mm ≤ H4 ≤ H2 / 2.

6. The cell cover assembly according to claim 3, characterized in that, Along the X and / or Y directions, the first limiting portion extends out of the pole post through hole for a length of L1, satisfying 0.5 mm ≤ L1 ≤ 5 mm; And / or, the thickness of the first limiting part along the Z direction is H5, satisfying 0.5 mm ≤ H5 ≤ 2.5 mm.

7. The cell cover assembly according to claim 3, characterized in that, The upper insulating member includes a body portion and a protrusion portion connected along the Z direction. The body portion is sandwiched between the first limiting portion and the first surface. The protrusion portion is disposed around the side surface of the body portion away from the first surface. The protrusion portion surrounds the outer side of the first limiting portion along the XY direction. The height of the body portion along the Z direction is H6, which satisfies 0.5 mm ≤ H6 ≤ 2 mm.

8. The cell cover assembly according to claim 7, characterized in that, Along the Z direction, the side of the first limiting part away from the first surface extends beyond the side of the protrusion away from the first surface by a distance L2, satisfying 0.2 mm ≤ L2 ≤ 1 mm.

9. A battery cell, characterized in that, include: The housing has an opening at at least one end; An electrode assembly is disposed within the housing, and an electrode tab is provided at one end of the electrode assembly near the opening; The cell cover assembly according to any one of claims 1 to 8, wherein the cover is disposed over the opening and connected to the housing.

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

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