Sealing element, battery cell and battery pack

Abstract

The utility model provides a sealing element, a battery monomer and a battery pack, the sealing element and a top cover comprise a welding area for welding, one side of the sealing element close to the welding area is provided with a first groove, and one side of the sealing element far away from the welding area is provided with a second groove. Wherein the diameters of areas defined by the first side wall of the first groove and the second side wall of the second groove are gradually increased in the corresponding opening direction, and the sealing piece meets the following conditions that X is smaller than or equal to 0.2 mm, and J2 / J1 is larger than or equal to 0.1 and smaller than or equal to 1; wherein X is the distance between the axis of the first groove and the axis of the second groove, J1 is the size of the first opening of the first groove in the radial direction of the first groove, and J2 is the size of the second opening of the second groove in the radial direction of the first groove. The material of the sealing element provided by the utility model can better flow to the welding area in the cooling shrinkage process, so that the stress concentration can be effectively avoided, and the risk that the sealing element is cracked or fractured is reduced.

Description

Technical Field

[0001] This utility model relates to the field of batteries, specifically to a sealing component, a battery cell, and a battery pack. Background Technology

[0002] After the electrolyte injection process is completed, a seal is typically welded to the battery cover to seal the electrolyte injection hole in the cover, preventing electrolyte leakage. However, common seal structures are susceptible to stress during welding, which can cause cracks or breakage, leading to insufficient battery airtightness and ultimately affecting battery safety. Utility Model Content

[0003] The embodiments of this utility model provide a sealing element, a battery cell, and a battery pack to solve the problem that sealing elements in related technologies are prone to cracking or breakage.

[0004] In a first aspect, embodiments of the present invention provide a sealing element suitable for installation on a top cover. The sealing element and the top cover include a welding area for welding. A first groove is provided on the side of the sealing element near the welding area, and a second groove is provided on the side of the sealing element away from the welding area. The diameters of the areas enclosed by the first sidewall of the first groove and the second sidewall of the second groove gradually increase along the corresponding opening direction. The sealing element satisfies the following conditions: X≤0.2mm, 0.1≤J2 / J1≤1. Wherein, X is the distance between the axis of the first groove and the axis of the second groove, J1 is the radial dimension of the first opening of the first groove, and J2 is the radial dimension of the second opening of the second groove.

[0005] In one embodiment, the orthographic projection of the second sidewall onto the plane containing the first top wall of the first groove is located within the orthographic projection of the first sidewall onto the plane containing the first top wall of the first groove.

[0006] In one embodiment, the first sidewall and / or the second sidewall are provided with chamfers.

[0007] In one embodiment, the top of the seal is adapted to be welded to the top cover, and the top includes a deformable portion adapted to deform toward the welding area between the seal and the top cover.

[0008] In one embodiment, the deformable portion has a radial dimension of 0.3 mm to 2 mm in the seal.

[0009] In one embodiment, the seal has a first side surface; the top cover has a mounting groove for mounting the seal, and the top cover has a second side surface surrounding the mounting groove; wherein the first side surface is adapted to abut against the second side surface and form an angle with the second side surface.

[0010] In one embodiment, the first side is adapted to form a mating gap with the second side, and the seal is adapted to be installed on the top cover by a welded portion, at least a portion of which is adapted to fill the mating gap and seal the mating gap.

[0011] In one embodiment, the seal further has a first bottom surface; the top cover further has a second bottom surface forming a mounting groove; wherein the angle between the first side surface and the first bottom surface and the angle between the second side surface and the second bottom surface satisfy: N = M + K, where N is the angle between the first side surface and the first bottom surface, M is the angle between the second side surface and the second bottom surface, and -10° ≤ K ≤ 10°.

[0012] In one embodiment, the top cover is provided with a mounting groove for mounting a seal, and the seal satisfies the following condition: -0.5mm≤dh≤0.5mm; where d is the depth of the mounting groove and h is the dimension of the seal in the depth direction of the mounting groove.

[0013] Secondly, embodiments of the present invention provide a battery cell that includes the sealing element of the first aspect.

[0014] Thirdly, embodiments of the present invention provide a battery pack that includes the battery cells of the second aspect.

[0015] This invention provides a sealing element, a battery cell, and a battery pack. The sealing element has a first groove at its bottom and a second groove at its top. The diameters of the areas enclosed by the first sidewall of the first groove and the second sidewall of the second groove gradually increase along their respective opening directions. The sealing element satisfies the following conditions: X ≤ 0.2 mm, 0.1 ≤ J2 / J1 ≤ 1; where X is the distance between the axes of the first and second grooves, J1 is the radial dimension of the first opening of the first groove, and J2 is the radial dimension of the second opening of the second groove. Because the angle between the streamline direction of the area between the first and second grooves and the contraction direction of the welding area is small, the material of the sealing element can flow better towards the welding area during cooling and contraction, effectively avoiding stress concentration. Furthermore, the relatively dense streamline structure between the first and second grooves facilitates material flow and reduces the risk of localized stress concentration caused by poor material flow. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the sealing element assembled on the top cover according to an embodiment of the present invention;

[0018] Figure 2 yes Figure 1 Top view of the middle seal 100 and the top cover 110;

[0019] Figure 3 yes Figure 2 Cross-sectional view of the middle seal 100 and the top cover 110;

[0020] Figure 4 yes Figure 3 Enlarged view of section A;

[0021] Figure 5 yes Figure 4 A cross-sectional view of the central seal 100;

[0022] Figure 6 yes Figure 5 A schematic diagram simulating the flow lines of the internal material of the seal;

[0023] Figure 7 yes Figure 4 A partial enlarged view of the central sealing element 100;

[0024] Explanation of reference numerals in the attached figures:

[0025] 100. Seal; 110. Top cover; 120. First groove; 121. First side wall; 130. Second groove; 131. Second side wall; 140. Chamfer; 150. Deformation part; 161. First side; 162. Second side; 163. Second bottom wall; 164. First top wall; 166. Second bottom surface; 170. Fitting clearance. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model. In addition, it should be understood that the specific embodiments described herein are only for illustration and explanation of the present utility model and are not intended to limit the present utility model. In the present utility model, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0027] To address the problem of cracks or breakage in seals in related technologies, embodiments of this utility model provide a seal 100 for installation on a top cover 110. The seal and the top cover include a welding area for welding, wherein the welding area is the portion of the seal 100 and the top cover 110 directly exposed to a welding laser during the welding process. See also... Figures 1 to 5 , Figure 1 This is a schematic diagram of the structure of the sealing element 100 assembled with the top cover 110 according to an embodiment of the present invention. Figure 2 yes Figure 1 Top view of the middle seal 100 and the top cover 110. Figure 3 yes Figure 2 Cross-sectional view of the middle seal 100 and the top cover 110. Figure 4 yes Figure 3 An enlarged view of part A in the middle. Figure 5 yes Figure 4 A cross-sectional view of the sealing element 100 shows a first groove 120 at the bottom and a second groove 130 at the top. The diameters of the areas enclosed by the first sidewall 121 of the first groove 120 and the second sidewall 131 of the second groove 130 gradually increase along their respective opening directions. The sealing element 100 satisfies the following conditions: X ≤ 0.2 mm, 0.1 ≤ J2 / J1 ≤ 1; where X is the distance between the axis of the first groove 120 and the axis of the second groove 130, J1 is the radial dimension of the first opening of the first groove 120, and J2 is the radial dimension of the second opening of the second groove 130. The radial direction of the first groove 120 refers to the direction from the center of the first top wall 164 of the first groove 120 to its edge.

[0028] For details, please refer to Figure 6 , Figure 6 yes Figure 5 The diagram shows the internal material flow lines of the seal 100. The first groove 120 and the second groove 130 of the seal 100 are manufactured using an extrusion molding process. During the extrusion molding process, the material inside the seal 100 is subjected to extrusion pressure, thus forming a flow line. Figure 6 The streamlined structure shown refers to the arrangement of the internal microstructure of the seal 100 along a certain direction when subjected to compressive force. This structure is usually microscopic, rather than a shape that can be directly observed macroscopically. Figure 6The streamlined shapes are simulated for ease of explanation of the principle. The streamlines are denser in the region between the first groove 120 and the second groove 130, while they are relatively sparser in the remaining regions. During the welding process between the seal 100 and the top cover 110, the weld area melts due to heat absorption. During the cooling process of the weld area, the material of the seal 100 shrinks, causing the material between the first groove 120 and the second groove 130 in the seal 100 to tend to be attracted to the weld area. That is, the material between the first groove 120 and the second groove 130 is affected by a pulling force that extends obliquely upwards and points towards the weld area. Figure 6 As can be seen, the simulated flow line direction of the internal material of the part of the seal 100 near the first groove 120 is also along the oblique upward direction and pointing towards the welding area, and the included angle between the two is small. This allows the internal material of the part of the seal 100 near the first groove 120 to better extend and flow towards the welding area, thereby effectively avoiding stress concentration.

[0029] Furthermore, the relatively dense streamlined structure between the first groove 120 and the second groove 130 facilitates material flow and reduces the risk of localized stress concentration caused by poor material flow. Through this structural design, the stress on the seal 100 during the welding process can be effectively released, thereby significantly reducing the risk of cracks or fractures caused by stress concentration. This allows the seal 100 to maintain higher stability and durability after welding, ensuring its sealing performance and reliability in actual use.

[0030] Experiments have verified that when the diameters of the regions enclosed by the first sidewall 121 of the first groove 120 and the second sidewall 131 of the second groove 130 of the seal 100 are designed to gradually increase along the corresponding opening direction, and the seal 100 meets the above conditions, the interior of the seal 100 can form a structure as shown above. Figure 6 The streamlined structure shown ensures that the stress of the seal 100 can be released more easily during the shrinkage process after welding, thereby reducing the risk of stress concentration in the structure and ensuring the reliability of the seal 100.

[0031] In addition, the first groove 120 can also be used to accommodate a sealing nail for sealing the injection hole, thereby enhancing the sealing of the injection hole in the top cover 110.

[0032] To further enhance the stress relief capability of the seal 100 during the cooling process, in some embodiments, see [reference needed]. Figure 4The orthographic projection of the second sidewall 131 onto the plane containing the first top wall 164 of the first groove 120 is set to lie within the orthographic projection of the first sidewall 121 onto the plane containing the first top wall 164 of the first groove 120. Experimental verification shows that when the seal 100 meets this structural condition, it can be used as a reference. Figure 6 The simulated streamline distribution between the first and second grooves is relatively uniform, which can better release the stress generated during the cooling process, thereby greatly reducing the risk of structural damage caused by stress concentration.

[0033] In some embodiments, see Figure 4 The seal 100 satisfies the following condition: the first sidewall 121 and / or the second sidewall 131 are provided with chamfers 140. The first groove 120 includes a first top wall 164, and the seal 100 satisfies at least one of the following: the connection between the first sidewall 121 and the first top wall 164 is provided with a chamfer 140, and the connection between the second sidewall 131 and the second bottom wall 163 is provided with a chamfer 140.

[0034] Specifically, during the cooling process after welding of the seal 100, the material between the first groove 120 and the second groove 130 is attracted to the welding area, causing the portion between the second bottom wall 163 and the first top wall 164 to tend to bend upwards. By providing a chamfer 140 at the connection between the first side wall 121 and the first top wall 164 and / or the second side wall 131 and the second bottom wall 163, the bending resistance of the portion between the second bottom wall 163 and the first top wall 164 in the seal 100 can be strengthened to a certain extent, thereby reducing the risk of structural damage to the seal 100 during cooling. Preferably, the bending resistance of the portion between the second bottom wall 163 and the first top wall 164 is strongest when both the connection between the first side wall 121 and the second bottom wall 163 and the second side wall 131 and the first top wall 164 are provided with chamfers 140.

[0035] In some embodiments, see Figure 4 The top of the seal 100 is adapted to be welded to the top cover 110. The top includes a deformable portion 150, which is adapted to deform towards the welding area between the seal 100 and the top cover 110. Specifically, when the welding area between the seal 100 and the top cover 110 shrinks due to cooling, the deformable portion 150 can locally deform towards the welding area to release the stress originally concentrated in the welding area. This makes the stress distribution of the seal 100 more uniform, thereby reducing the risk of cracking or breaking of the seal 100 due to excessive local stress in the welding area, and thus ensuring the reliability of the seal 100.

[0036] In some embodiments, please refer to Figure 5The radial dimension W of the deformable portion 150 on the seal 100 is set within the range of 0.3 mm to 2 mm. This structural design aims to ensure that the seal 100 can effectively seal the injection hole after welding and withstand the thermal expansion and stress concentration that may occur during the welding process. Specifically, see [link to relevant documentation]. Figure 2 From a top-down view, the deformable part 150 appears as a ring-shaped area, where W is the width of the ring.

[0037] Experiments have shown that when the width W of the deformable part 150 is less than 0.3 mm, the welding area of ​​the seal 100 is too narrow, resulting in insufficient sealing of the injection hole and poor sealing performance. When the width W of the deformable part 150 is greater than 2 mm, its excessive width requires greater stress to deform, increasing the difficulty of deformation and potentially preventing it from adequately adapting to structural changes caused by thermal expansion after welding, thus affecting the reliability of the sealing system. Therefore, the optimal design width range for the deformable part 150 is 0.3 mm to 2 mm. Within this range, the deformable part 150 provides sufficient welding area during welding while ensuring flexibility in deformation after welding, avoiding the adverse effects of being too narrow or too wide.

[0038] In some embodiments, please refer to Figure 6 , Figure 7 , Figure 7 yes Figure 4 A partially enlarged view of the sealing element 100 shows that the sealing element 100 has a first side surface 161 facing the top cover 110. The top cover 110 includes a mounting groove for mounting the sealing element 100 and a second side surface 162 for forming the mounting groove. The first side surface 161 abuts against the second side surface 162 and forms an angle with the second side surface 162.

[0039] On the one hand, the included angle formed by the first side 161 and the second side 162 enhances the stability of the seal 100. When the first side 161 of the seal 100 contacts the second side 162 of the top cover 110, the clamping force applied by the second side 162 can firmly fix the seal 100 in the mounting groove, preventing displacement of the seal 100 during operation and thus ensuring the sealing performance of the seal 100. Secondly, during the welding process of the seal 100, the seal 100 will undergo thermal expansion due to a sudden temperature rise. The included angle design helps the seal 100 disperse the deformation stress caused by thermal expansion, maintaining its stability during temperature changes, thereby reducing the risk of seal failure due to excessive deformation of the seal 100.

[0040] Furthermore, in some embodiments, the first side 161 and the second side 162 form a mating gap 170. The seal 100 is mounted to the top cover 110 via a welded portion, at least a portion of which fills and seals the mating gap 170. Specifically, during the welding process between the seal 100 and the top cover 110, at least a portion of the welded portion fills the mating gap 170. The design of the mating gap 170 not only facilitates the installation of the seal 100 but also provides sufficient space for the thermal expansion of the seal 100. During the welding process, the seal 100 is affected by high temperatures and expands. If the seal 100 cannot expand freely in its installation position, it may damage the structure of the seal 100 itself and the structure of the top cover 110. By providing expansion space for the seal 100, the mating gap 170 can effectively alleviate the internal pressure of the seal 100 due to thermal expansion, thereby reducing the risk of damage to the top cover 110 or the seal 100.

[0041] In some embodiments, please refer to Figure 4 , Figure 7 The sealing element 100 has a first side surface 161 and a first bottom surface, and the top cover 110 has a second side surface 162 and a second bottom surface 166 forming a mounting groove. The angle between the first side surface 161 and the first bottom surface, and the angle between the second side surface 162 and the second bottom surface 166, satisfy the following condition: N = M + K, where N is the angle between the first side surface 161 and the first bottom surface, M is the angle between the second side surface 162 and the second bottom surface 166, and -10° ≤ K ≤ 10°.

[0042] Experiments have shown that, firstly, if MN > 10°, the seal 100 will experience significant resistance during installation, making installation difficult and potentially preventing it from being installed properly. Secondly, the large difference in angle increases the clearance 170 between the first side 161 and the second side 162, affecting the sealing effect.

[0043] On the other hand, if MN < -10°, the welding position between the top cover 110 and the seal 100 will be too far apart, which may prevent precise alignment during welding, thus affecting the welding quality and even the welding strength, thereby affecting the sealing effect of the seal 100.

[0044] Therefore, ensuring that the difference K between the included angles N and M is controlled between -10° and 10° is to guarantee the fitting accuracy between the seal 100 and the mounting groove of the top cover 110, thereby optimizing the installation process and avoiding problems such as installation difficulties, poor fit, or poor sealing effect caused by excessive angle differences. This structural design not only improves the assembly efficiency of the seal 100 but also ensures the reliability of the sealing system, reducing the risk of problems such as poor welding or seal failure.

[0045] To ensure the structural strength of the seal 100 during use, in some embodiments, the depth of the second groove 130 of the seal 100 is set between 0.1 mm and 0.5 mm, and the thickness of the thinnest part of the seal 100 is set between 0.3 mm and 0.5 mm.

[0046] Specifically, the depth of the second groove 130 is designed to be between 0.1mm and 0.5mm, aiming to balance the structural strength and functional requirements of the seal 100. If the second groove 130 is too deep, the area between the first groove 120 and the second groove 130 will be weak, resulting in poor pressure resistance and a higher risk of breakage of the seal 100 during deformation. If the second groove 130 is too shallow, the deformation portion 150 will be difficult to deform during welding, thus failing to achieve the effect of stress dispersion. By controlling the thickness of the thinnest part of the seal 100 between 0.3mm and 0.5mm, it is further ensured that the seal 100 is not easily deformed or broken by external forces during operation.

[0047] In some embodiments, please refer to Figure 4 The difference between the depth d of the mounting groove and the dimension h of the seal 100 in the depth direction of the mounting groove is controlled between -0.5mm and 0.5mm.

[0048] Specifically, experiments have shown that when the absolute value of the difference between the two is greater than 0.5mm, it will cause a mismatch between the dimensions of the seal 100 and the mounting groove, increasing the difficulty of installation. Secondly, the large height difference between the two can lead to welding position deviations during the welding process, and may even cause seal failure.

[0049] Therefore, by strictly controlling the difference between the depth d of the mounting groove and the dimension h of the seal 100 in the direction of the mounting groove depth to within the range of -0.5mm to 0.5mm, the installation difficulties and welding inconveniences caused by excessive height difference can be effectively avoided.

[0050] This utility model provides a sealing element 100, which has a first groove 120 at its bottom and a second groove 130 at its top. The diameters of the areas enclosed by the first sidewall 121 of the first groove 120 and the second sidewall 131 of the second groove 130 gradually increase along their respective opening directions. Furthermore, the sealing element 100 satisfies the following conditions: X ≤ 0.2 mm, 0.1 ≤ J2 / J1 ≤ 1; where X is the distance between the axis of the first groove 120 and the axis of the second groove 130, J1 is the radial dimension of the first opening of the first groove 120, and J2 is the radial dimension of the second opening of the second groove 130. Because the angle between the streamline direction of the area between the first groove 120 and the second groove 130 and the shrinkage direction of the welding area is small, the material of the seal 100 can flow better to the welding area during the cooling and shrinkage process, thereby effectively avoiding stress concentration. In addition, the relatively dense streamline structure between the first groove 120 and the second groove 130 helps to realize the flow of material and reduces the risk of local stress concentration caused by poor material flow.

[0051] This utility model also provides a battery cell, which includes the aforementioned sealing element 100 and has all the advantages of the aforementioned sealing element 100, which will not be repeated here.

[0052] This utility model also provides a battery pack, which includes the above-mentioned battery cells and has all the advantages of the above-mentioned battery cells, which will not be repeated here.

[0053] The embodiments of this utility model have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A sealing element suitable for installation on a top cover, characterized in that, The seal and the top cover include a welding area for welding, and the seal has a first groove on the side near the welding area and a second groove on the side away from the welding area. Wherein, the diameter of the area enclosed by the first sidewall of the first groove and the second sidewall of the second groove gradually increases along the corresponding opening direction, and the sealing element satisfies the following conditions: X≤0.2mm, 0.1≤J2 / J1≤1; where X is the distance between the axis of the first groove and the axis of the second groove, J1 is the radial dimension of the first opening of the first groove, and J2 is the radial dimension of the second opening of the second groove.

2. The seal according to claim 1, characterized in that, The orthographic projection of the second sidewall onto the plane containing the first top wall of the first groove lies within the orthographic projection of the first sidewall onto the plane containing the first top wall of the first groove.

3. The seal according to claim 1, characterized in that, The first sidewall and / or the second sidewall are provided with chamfers.

4. The seal according to claim 1, characterized in that, The top of the seal is adapted to be welded to the top cover, and the top includes a deformable portion adapted to deform toward the welded area.

5. The seal according to claim 4, characterized in that, The deformable portion has a radial dimension of 0.3 mm to 2 mm in the seal.

6. The seal according to claim 1, characterized in that, The seal has a first side surface; the top cover has a mounting groove for mounting the seal, and the top cover has a second side surface surrounding the mounting groove; wherein the first side surface is adapted to abut against the second side surface and form an angle with the second side surface.

7. The seal according to claim 6, characterized in that, The first side is adapted to form a mating gap with the second side, the seal is adapted to be installed on the top cover by a welded portion, at least a portion of the welded portion is adapted to fill the mating gap and seal the mating gap.

8. The seal according to claim 6, characterized in that, The seal also has a first bottom surface; the top cover also has a second bottom surface forming the mounting groove; wherein the angle between the first side surface and the first bottom surface and the angle between the second side surface and the second bottom surface satisfy: N = M + K, where N is the angle between the first side surface and the first bottom surface, M is the angle between the second side surface and the second bottom surface, and -10° ≤ K ≤ 10°.

9. The seal according to any one of claims 1-8, characterized in that, The top cover is provided with a mounting groove for installing the sealing element, and the sealing element satisfies the following condition: -0.5mm≤dh≤0.5mm; where d is the depth of the mounting groove and h is the dimension of the sealing element in the depth direction of the mounting groove.

10. A single battery cell, characterized in that, Includes the seal as described in any one of claims 1-9.

11. A battery pack, characterized in that, Includes the battery cell as described in claim 10.

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