Battery cell casing, battery cell, battery pack and electrical equipment

Abstract

This utility model provides a battery cell housing, a battery cell, a battery pack, and an electrical device. The battery cell housing includes a base plate, which has two welding platforms and an explosion-proof platform. Each of the two welding platforms includes a welding surface, and the explosion-proof platform includes a scoring surface with scoring marks. The welding surface and the scoring surface are on different planes, thereby maintaining the pressure relief performance of the scoring marks.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a cell housing, a cell, a battery pack, and an electrical device. Background Technology

[0002] The new national standard GB38031-2025 requires that battery cells not catch fire or explode under extreme test conditions, such as nail penetration and thermal runaway tests. Related technologies increase the pressure relief path of the battery cell by designing an explosion-proof structure at the casing end. However, the casing end typically needs to be welded to the internal winding core and the external busbar, and the welding process can affect the pressure relief performance of the explosion-proof structure at the casing end. Utility Model Content

[0003] The embodiments of this utility model provide a battery cell housing, a battery cell, a battery pack, and an electrical device, which can improve the technical problem of unstable pressure relief performance of the explosion-proof structure at the housing end of the battery cell.

[0004] In a first aspect, embodiments of the present invention provide a battery cell housing, comprising:

[0005] The base plate has two welding platforms and an explosion-proof platform;

[0006] Both of the aforementioned welding platforms include a welding surface, and the explosion-proof platform includes a serrated surface with serrations. The welding surface and the serrated surface are located on different planes.

[0007] In one embodiment, the two welding platforms include a first welding platform and a second welding platform. The cell housing is adapted for the cell. The cell includes an electrode assembly located within the cell housing and a busbar connected to the electrode assembly. The electrode assembly is located within the cell housing. The first welding platform includes a first welding surface configured to weld to the busbar. The second welding platform includes a second welding surface adapted to weld to a busbar outside the cell housing.

[0008] In one embodiment, the thickness of the first welding platform is a, the thickness of the second welding platform is c, and the thickness of the explosion-proof platform is d, where a:c:d = (0.3~1.0):1:(0.3~1).

[0009] In one embodiment, a ranges from 0.3 mm to 1.5 mm; and / or, c ranges from 0.3 mm to 2.0 mm;

[0010] And / or, d ranges from 0.3mm to 1.5mm.

[0011] In one embodiment, the first welding platform, the explosion-proof platform, and the second welding platform are arranged sequentially along the middle of the base plate towards the side of the base plate.

[0012] In one embodiment, the second welding platform includes a first top surface opposite to the second welding surface. The first welding surface of the first welding platform protrudes towards the interior of the cell housing relative to the first top surface of the second welding platform. The height by which the first welding surface of the first welding platform protrudes relative to the first top surface of the second welding platform is b. The thickness of the first welding platform is a, where b:a = 0.3~1.0.

[0013] In one embodiment, the explosion-proof platform includes a first bottom surface opposite to the etched surface. The first bottom surface protrudes outward from the housing relative to the second welding surface of the second welding platform. The height by which the first bottom surface of the explosion-proof platform protrudes relative to the second welding surface of the second welding platform is e. The thickness of the explosion-proof platform is d, where e:d = 0.3~1.0.

[0014] In one embodiment, the explosion-proof platform, the second welding platform, and the first welding platform are arranged sequentially along a direction away from the center of the base plate and pointing towards the side of the base plate.

[0015] In one embodiment, the first welding surface of the first welding platform protrudes towards the interior of the cell housing relative to the etched surface of the explosion-proof platform, the height of the protrusion of the first welding surface of the first welding platform relative to the etched surface of the explosion-proof platform is b, and the thickness of the first welding platform is a, where b:a = 0.3~1.0.

[0016] In one embodiment, the second welding platform has a first top surface opposite to the second welding surface, and the scoring surface of the explosion-proof platform protrudes towards the interior of the cell housing relative to the first top surface of the second welding platform. The height by which the scoring surface of the explosion-proof platform protrudes relative to the first top surface of the second welding platform is e, and the thickness of the explosion-proof platform is d, where e:d = 0.3~1.0.

[0017] In one embodiment, b ranges from 0.3 mm to 2.0 mm; and / or a ranges from 0.3 mm to 1.5 mm.

[0018] In one embodiment, e ranges from 0.3 mm to 2.0 mm; and / or d ranges from 0.3 mm to 1.5 mm.

[0019] In one embodiment, the residual thickness at the location of the indentation is f, where f ranges from 0.05 mm to 0.20 mm.

[0020] Secondly, embodiments of the present invention provide a battery cell, the battery cell including the aforementioned battery cell housing and electrode assembly, the electrode assembly being disposed within the battery cell housing.

[0021] In one embodiment, the battery cell further includes a busbar located within the housing, the busbar having a pressure relief hole facing the groove.

[0022] In one embodiment, the busbar further includes a first busbar welding platform, which is welded to the electrode assembly.

[0023] In one embodiment, the busbar further includes a second busbar welding platform, which is welded to the cell housing.

[0024] In one embodiment, the thickness of the first busbar welding platform is h1, and the thickness of the second busbar welding platform is h2, where h2:h1 = 0.1~1.0.

[0025] In one embodiment, h1 ranges from 0.15 mm to 1.5 mm; and / or h2 ranges from 0.2 mm to 1.2 mm.

[0026] In one embodiment, the bottom end face of the second busbar welding platform protrudes outward from the housing relative to the bottom end face of the first busbar welding platform. The height by which the bottom end face of the second busbar welding platform protrudes relative to the bottom end face of the first busbar welding platform is h3, and the thickness of the second busbar welding platform is h2, where h3:h2 = 0.2~1.0.

[0027] In one embodiment, the pressure relief hole, the first manifold welding platform, and the second manifold welding platform are arranged sequentially along the middle of the manifold towards the side of the manifold.

[0028] Thirdly, embodiments of the present invention provide a battery pack, the battery pack including a housing and a plurality of battery cells located inside the housing, the battery cells being configured as described above.

[0029] Fourthly, an embodiment of the present invention provides an electrical device, which includes the aforementioned battery pack.

[0030] The beneficial effects of the embodiments of this utility model are as follows:

[0031] In the embodiments of this utility model, by setting the welding surfaces of the two welding platforms and the etched surfaces of the explosion-proof platform to be on different planes, the high energy used in the welding process of the two welding platforms of the cell shell is unlikely to damage the etched surfaces on the explosion-proof platform, thereby maintaining the pressure relief performance of the etched surfaces. Attached Figure Description

[0032] 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 based on these drawings without creative effort.

[0033] Figure 1 This is an exploded structural diagram of the battery cell provided in an embodiment of this utility model;

[0034] Figure 2 This is a cross-sectional structural diagram of a battery cell provided in one embodiment of the present invention;

[0035] Figure 3 This is a cross-sectional structural diagram of the shell provided in one embodiment of the present utility model;

[0036] Figure 4 This is a partial structural schematic diagram of the housing provided in one embodiment of the present utility model;

[0037] Figure 5 This is a cross-sectional structural diagram of a battery cell provided in another embodiment of this utility model;

[0038] Figure 6 yes Figure 5 A magnified view of a portion of the image;

[0039] Figure 7 This is a cross-sectional structural schematic diagram of the shell provided in another embodiment of this utility model;

[0040] Figure 8 This is a partial structural schematic diagram of the shell provided in another embodiment of the present utility model;

[0041] Figure 9 This is a three-dimensional structural schematic diagram of the busbar provided in one embodiment of the present utility model;

[0042] Figure 10 This is a cross-sectional structural diagram of the busbar provided in one embodiment of the present invention.

[0043] Icon labels:

[0044] 100. Battery cell; 1. Battery cell housing; 11. Base plate; 12. Top; 13. First welding platform; 131. First welding surface; 14. Second welding platform; 141. Second welding surface; 142. First top surface; 15. Explosion-proof platform; 151. Score surface; 152. First bottom surface; 2. Electrode assembly; 3. Top cover assembly; 31. Top cover; 32. Sealing plug; 33. Sealing sheet; 41. Inner insulating film; 42. Outer insulating film; 43. First insulating component; 44. Second insulating component; 5. Busbar; 51. Pressure relief hole; 52. First busbar welding platform; 53. Second busbar welding platform; 6. Score; Detailed Implementation

[0045] 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.

[0046] The new national standard GB38031-2025 requires that battery cells not catch fire or explode under extreme test conditions, such as needle penetration and thermal diffusion tests. Related technologies increase the pressure relief path of the battery cell by adding an explosion-proof valve to the bottom plate of the cell casing. However, the bottom plate of the casing usually needs to be welded to the electrode assembly inside the cell and the busbar outside the cell. The welding process can affect the pressure relief performance of the explosion-proof valve on the bottom plate. For example, the high-energy laser used for welding can damage the explosion-proof valve structure, causing the pressure relief threshold of the explosion-proof valve to be lower or higher than the set pressure relief threshold.

[0047] Embodiments of this application provide an electrical device that includes a battery pack or at least one battery cell. The electrical device may be an electric vehicle, an energy storage system, a power tool, or an electronic product.

[0048] Embodiments of this application provide a battery pack, which includes a housing and a plurality of battery cells located within the housing. The battery pack can be a power battery pack or an energy storage battery pack.

[0049] Embodiments of this application provide a battery cell 100, such as Figure 1 and Figure 2As shown, the battery cell 100 can be a cylindrical battery cell or a square battery cell. In the embodiments of this application, a cylindrical battery cell is used as an example for description. The battery cell 100 includes a battery cell housing 1, an electrode assembly 2, a top cover assembly 3, and a busbar 5.

[0050] like Figure 3 As shown, the battery cell housing 1 includes a bottom plate 11 and a top plate 12 opposite each other along the height direction, wherein the bottom plate 11 is closed and the top plate 12 is open, and the top cover assembly 3 is connected to the top plate 12 of the battery cell housing 1. The battery cell housing 1 can be an aluminum shell, and the bottom plate 11 and the side plate of the battery cell housing 1 can be integrally formed, or the bottom plate 11 and the side plate of the battery cell housing 1 can be separately formed and welded together.

[0051] The electrode assembly 2 includes multiple positive electrode sheets, multiple negative electrode sheets, and multiple separators located between the multiple positive electrode sheets and the multiple negative electrode sheets. The electrode assembly 2 can be a wound assembly, where the multiple positive electrode sheets, multiple separators, and multiple negative electrode sheets are stacked in a wound manner to form the electrode assembly. In one embodiment provided in this application, the multiple positive electrode sheets of the electrode assembly 2 are connected to the top cover assembly 3, and the multiple negative electrode sheets of the electrode assembly 2 are connected to the cell housing 1. In other alternative embodiments, the multiple positive electrode sheets of the electrode assembly 2 are connected to the cell housing 1, and the multiple negative electrode sheets of the electrode assembly 2 are connected to the top cover assembly 3.

[0052] The top cover assembly 3 includes a top cover 31, a sealing plug 32, and a sealing plate 33. The top cover 31 is connected to the top 12 of the cell housing 1. The top cover 31 is also provided with an injection hole. The sealing plug 32 and the sealing plate 33 are configured to seal the injection hole.

[0053] An inner insulating film 41 is provided between the electrode assembly 2 and the cell housing 1, and an outer insulating film 42 is provided on the outer surface of the cell housing 1. A first insulating element 43 is provided on the electrode assembly 2 near the top cover assembly 3, and a second insulating element 44 is provided on both the electrode assembly 2 and the bottom plate 11 of the cell housing 1. The first insulating element 43 and the second insulating element 44 can be insulating adhesive paper, thereby improving the insulation performance of the cell 100.

[0054] In some embodiments, such as Figures 2 to 4 As shown, a busbar 5 is also provided between the electrode assembly 2 and the base plate 11 of the cell housing 1. The busbar 5 can be a positive busbar or a negative busbar. The busbar 5 is used to connect multiple positive electrode plates of the electrode assembly 2 and the cell housing 1, or the busbar 5 is used to connect multiple negative electrode plates of the electrode assembly 2 and the cell housing 1.

[0055] In some embodiments provided in this application, reference continues to be made to Figures 2 to 4A notch 6 is provided on the base plate 11 of the cell housing 1. Two welding platforms and one explosion-proof platform 15 are provided on the base plate 11 of the cell housing 1, and the notch 6 is located on the explosion-proof platform 15. The two welding platforms are configured to weld the cell housing 1. Both welding platforms include a welding surface, and the explosion-proof platform 15 has a notch surface 151. The notch 6 is located on the notch surface 151, and the welding surface and the notch surface 151 are on different planes.

[0056] Understandably, since the etched surface 151 and the welding surface are on different planes, the high energy used in the welding process during the welding of the two welding platforms of the cell housing 1 is unlikely to damage the etched surface 151 of the explosion-proof platform 15, thereby maintaining the pressure relief performance of the etched surface 6.

[0057] In some embodiments, such as Figure 3 and Figure 4 As shown, the two welding platforms on the base plate 11 of the cell housing 1 include a first welding platform 13 and a second welding platform 14. The first welding platform 13 is configured to weld the electrode assembly 2 to the busbar 5, and the second welding platform 14 is configured to weld the external busbar of the cell housing 1 to the cell housing 1. This enables the series or parallel connection of multiple cells 100.

[0058] In some embodiments, such as Figure 4 As shown, the thickness of the first welding platform 13 is 'a', the thickness of the second welding platform 14 is 'c', and the thickness of the explosion-proof platform 15 is 'd', with a:c:d = (0.3~1.0):1:(0.3~1). The inventors, through designing different ratios of a, d, and c and conducting cell capacity analysis experiments, strength tests at the first welding platform 13, and strength tests at the explosion-proof platform 15, found that only when a:c:d = (0.3~1.0):1:(0.3~1) is it beneficial to maintain the performance of the cell 100, the structural strength of the two welding platforms, and the structural strength of the explosion-proof platform 15. The thickness 'c' of the second welding platform 14 is set as a constant. The cell capacity is obtained through analysis and calculation.

[0059] Table 1. Experimental Table of Thickness Ratio of Two Welding Platforms and Explosion-proof Platforms

[0060]

[0061] Comparing the experimental examples and comparative examples in Table 1 (number 1), it is found that when a:c > 1.0, the first welding platform 13 has a larger thickness, meaning it is taller, resulting in it occupying more space inside the cell housing 1, thus leading to a smaller capacity of the cell 100. Comparing the experimental examples and comparative examples in Table 1 (number 2), it is found that when a:c < 0.3, the first welding platform 13 is thinner, resulting in lower structural strength. Comparing the experimental examples and comparative examples in Table 1 (number 3), it is found that when d:c > 1.0, the explosion-proof platform 15 has a larger thickness, meaning it is taller, resulting in it occupying more space inside the cell housing 1, thus leading to a smaller capacity of the cell 100. By comparing the experimental example and the comparative example in Table 1, it was found that when d:c < 0.3, the thickness of the explosion-proof platform 15 is relatively thin, which leads to lower structural strength of the explosion-proof platform 15. Consequently, when the explosion-proof valve installed on the explosion-proof platform 15 is set with a grooved structure, the grooved area is prone to cracking.

[0062] In some embodiments, the thickness a of the first welding platform 13 ranges from 0.3 mm to 1.5 mm, the thickness c of the second welding platform 14 ranges from 0.3 mm to 2.0 mm, and the thickness d of the explosion-proof platform 15 ranges from 0.3 mm to 1.5 mm, thereby facilitating a balance between the structural strength of the first welding platform 13, the structural strength of the second welding platform 14, the structural strength of the explosion-proof platform 15, and the internal capacity of the battery cell 100.

[0063] In some specific embodiments, the thickness 'a' of the first welding platform 13 can be 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, or any value between any two of the above values, or a range between any two of the above values. The thickness 'c' of the second welding platform 14 can be 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2.0mm, or any value between any two of the above values, or a range between any two of the above values. The thickness d of the explosion-proof platform 15 can be 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, or any value between any two of the above, or a range between any two of the above values.

[0064] In some embodiments, such as Figure 3 and Figure 4 As shown, on the base plate 11 of the cell housing 1, the first welding platform 13, the explosion-proof platform 15, and the second welding platform 14 are arranged sequentially along the middle of the base plate 11 towards the side of the base plate 11, as follows. Figure 4 The x1 direction is shown. By placing the explosion-proof platform 15 between the first welding platform 13 and the second welding platform 14, a suitable distance is maintained between the explosion-proof platform 15 and both the first welding platform 13 and the second welding platform 14, thereby reducing the impact of welding on the first welding platform 13 and the second welding platform 14 on the explosion-proof performance of the groove 6 on the explosion-proof platform 15.

[0065] In some embodiments, the first welding surface 131 of the first welding platform 13 protrudes towards the interior of the cell housing 1 relative to the first top surface 142 of the second welding platform 14. The height by which the first welding surface 131 of the first welding platform 13 protrudes relative to the first top surface 142 of the second welding platform 14 is b, and the thickness of the first welding platform 13 is a, where b:a = 0.3~1.0. The inventors, through designing different ratios of a and b and conducting cell capacity analysis experiments and assembly stability tests of the electrode assembly 2 within the cell housing 1, found that only when b:a = 0.3~1.0 is it beneficial to simultaneously maintain the performance of the cell 100 and the assembly stability of the electrode assembly 2 within the cell housing 1. The thickness a of the first welding platform 13 is set to a constant value.

[0066] Table 2. Experimental table of the ratio of the inner convex height and the thickness of the first welding platform.

[0067]

[0068] A comparison of the experimental examples and comparative examples in Table 2 (Section 1) reveals that when b:a > 1.0, the first welding platform 13 protrudes significantly into the cell housing 1, resulting in a larger internal space occupied by the first welding platform 13 and thus a smaller capacity for the cell 100. A comparison of the experimental examples and comparative examples in Table 2 (Section 2) reveals that when b:a < 0.3, the first welding platform 13 protrudes less into the cell housing 1, making it difficult to achieve an interference fit between the first welding platform 13 and the electrode assembly 2. Consequently, after the cell 100 is assembled, the electrode assembly 2 is prone to shaking inside the cell housing 1.

[0069] In some embodiments, the explosion-proof platform 15 includes a first bottom surface 152 opposite to the etched surface 151, the first bottom surface 152 protruding outwards from the second welding surface 141 of the second welding platform 14 relative to the cell housing 1. The height of the protrusion of the first bottom surface 152 of the explosion-proof platform 15 relative to the second welding surface 141 of the second welding platform 14 is set to e, and the thickness of the explosion-proof platform 15 is set to d, where e:d = 0.3~1.0. The inventors, through designing different e:d ratios and conducting cell capacity analysis experiments and burst pressure value experiments of the etched surface 6, found that only when e:d = 0.3~1.0 is it beneficial to simultaneously maintain the performance of the cell 100 and the stability of the burst pressure value of the etched surface 6. The thickness d of the explosion-proof platform 15 is set to a constant value.

[0070] Table 3. Experimental Table of Ratio of Outward Protrusion Height to Thickness of Explosion-Proof Platform

[0071]

[0072] By comparing the experimental examples and comparative examples in Table 3 (Section 1), it was found that when e:d > 1.0, under the premise that the height of the cell housing 1 remains unchanged, the explosion-proof platform 15 protrudes significantly outward from the cell housing 1, resulting in a smaller internal space ratio of the cell housing 1 and thus a smaller capacity of the cell 100. By comparing the experimental examples and comparative examples in Table 3 (Section 2), it was found that when e:d < 0.3, the explosion-proof platform 15 protrudes less, and the first bottom surface 152 of the explosion-proof platform 15 is closer to the second welding surface 141 of the second welding platform 14. This means that when the second welding platform 14 is welded to the external busbar, the high-energy laser used for welding will affect the scoring structure of the scoring 6 on the explosion-proof platform 15, resulting in a lower burst value for the scoring 6 of the cell 100.

[0073] In some embodiments, such as Figure 5 and Figure 6 As shown, on the base plate 11 of the cell housing 1, the explosion-proof platform 15, the second welding platform 14, and the first welding platform 13 are arranged sequentially along the center of the base plate 11 towards the side of the base plate 11, as follows. Figure 8 The x1 direction is shown. By setting the explosion-proof platform 15 away from the second welding platform 14, when the cell housing 1 is welded to the external busbar at the second welding platform 14, the high-energy laser used for welding is unlikely to affect the structure of the engraving 6 on the explosion-proof platform 15.

[0074] In some embodiments, such as Figure 7 and Figure 8As shown, the top surface of the first welding platform 13 protrudes towards the interior of the cell housing 1 relative to the top surface of the explosion-proof platform 15. The height of this protrusion relative to the top surface of the explosion-proof platform 15 is set as b, and the thickness of the first welding platform 13 is a, with a b:a ratio of 0.3 to 1.0. Through designing different a:b ratios and conducting cell capacity analysis experiments and electrode assembly 2 assembly stability tests within the cell housing 1, the inventors found that only when b:a = 0.3 to 1.0 is it beneficial to simultaneously maintain the performance of the cell 100 and the assembly stability of the electrode assembly 2 within the cell housing 1. The relevant tests and results are shown in Table 2 above.

[0075] In some embodiments, continue to refer to Figure 7 and Figure 8 The top surface of the explosion-proof platform 15 protrudes towards the interior of the cell housing 1 relative to the top surface of the second welding platform 14. The height of this protrusion relative to the top surface of the second welding platform 14 is defined as *e*, and the thickness of the explosion-proof platform 15 is defined as *d*, with *e:d* = 0.3~1.0. Through designing different *e*:d ratios and conducting cell capacity analysis experiments and burst pressure value experiments on the notch 6, the inventors found that only when *e:d* = 0.3~1.0 is it beneficial to simultaneously maintain the performance of the cell 100 and the stability of the burst pressure value of the notch 6. The relevant tests and test results are shown in Table 2 above.

[0076] In some embodiments, the top surface of the first welding platform 13 protrudes into the cell housing 1 at a height of b relative to the top surface of the second welding platform 14, or the top surface of the first welding platform 13 protrudes into the cell housing 1 at a height of b relative to the top surface of the explosion-proof platform 15, wherein b ranges from 0.3 mm to 2.0 mm. This is beneficial for maintaining a suitable capacity for the cell 100 and for ensuring that after the cell 100 is assembled, an interference fit is formed between the electrode assembly 2 and the cell housing 1, thereby preventing the electrode assembly 2 from shaking in the cell housing 1.

[0077] In some specific embodiments, the height b by which the first welding surface 131 of the first welding platform 13 protrudes toward the inside of the cell housing 1 relative to the first top surface 142 of the second welding platform 14, or the height b by which the first welding surface 131 of the first welding platform 13 protrudes toward the inside of the cell housing 1 relative to the etched surface 151 of the explosion-proof platform 15, can be 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2.0mm, or any two of the above values, or any range between the above two values.

[0078] In some embodiments, the first bottom surface 152 of the explosion-proof platform 15 protrudes outward from the second welding surface 141 of the second welding platform 14 by a height e, or the scoring surface 151 of the explosion-proof platform 15 protrudes outward from the first top surface 142 of the second welding platform 14 by a height e, where e ranges from 0.3 mm to 2.0 mm. This helps to maintain a suitable capacity for the battery cell 100 and ensures a suitable distance between the explosion-proof platform 15 and the second welding platform 14, thereby reducing the impact of the high-energy laser used for welding on the explosion-proof valve structure on the explosion-proof platform 15 when the battery cell housing 1 is welded to the external busbar.

[0079] In some specific embodiments, the height e in which the bottom plate of the explosion-proof platform 15 protrudes outward toward the cell housing 1 relative to the bottom plate of the second welding platform 14, or the height e in which the top surface of the explosion-proof platform protrudes relative to the top surface of the second welding platform, can be 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2.0mm, or any value between any two of the above, or a range between any two of the above values.

[0080] In some embodiments, the notch 6 includes a notch located on the explosion-proof platform 15, with a residual thickness f at the notch, where f ranges from 0.05 mm to 0.20 mm. The inventors discovered through research that when the residual thickness f at the notch is greater than 0.2 mm, the burst pressure value of the notch 6 is too high. Conversely, when the residual thickness f at the notch is less than 0.05 mm, the burst pressure value of the notch 6 is too low, and the CPk does not meet the requirements.

[0081] In some specific embodiments, such as Figure 7 and Figure 8 As shown, the residual thickness f at the etched area can be 0.05mm, 0.08mm, 0.10mm, 0.12mm, 0.15mm, 0.18mm, 0.20mm, or any value between any two of the above, or a range between any two of the above values.

[0082] In some embodiments, such as Figure 7 and Figure 9 As shown, a pressure relief hole 51 is provided at the center of the busbar 5. The pressure relief hole 51 is positioned directly opposite the groove 6 so that the high-pressure gas generated inside the cell housing 1 can act on the groove 6 through the pressure relief hole 51 of the busbar 5 in sequence, causing the groove structure of the groove 6 to break, so that the high-pressure gas can escape to the outside of the cell housing 1.

[0083] In some embodiments, such as Figure 9 and Figure 10 As shown, the busbar 5 also includes a first busbar welding platform 52, which is located outside the pressure relief hole 51 and is welded to the electrode assembly 2.

[0084] In some embodiments, the busbar 5 further includes a second busbar welding platform 53, which is located outside the first busbar welding platform 52 and is welded to the cell housing 1. The pressure relief hole 51, the first busbar welding platform 52, and the second busbar welding platform 53 are arranged sequentially in a direction away from the center of the busbar 5.

[0085] In some embodiments, the first busbar welding platform 52 and the second busbar welding platform 53 are not coplanar. The top surface of the first busbar welding platform 52 protrudes towards the electrode assembly 2 relative to the top surface of the second busbar welding platform 53, and the bottom plate of the second busbar welding platform 53 protrudes towards the bottom plate 11 of the cell housing 1 relative to the bottom plate of the first busbar welding platform 52. This facilitates welding of the electrode assembly 2 to the first busbar welding platform 52 and welding of the cell housing 1 to the second busbar welding platform 53, and enables an interference fit between the busbar 5 and the cell housing 1, improving the reliability of the welding operation.

[0086] In some embodiments, the thickness of the first busbar welding platform 52 is set to h1, and the thickness of the second busbar welding platform 53 is set to h2, with h2:h1 = 0.1~1.0. The inventors analyzed the effects of different h1:h2 ratios and conducted experiments on cell capacity and the damage to the diaphragm caused by penetration welding between the second busbar welding platform 53 and the cell housing 1. They found that only when h2:h1 = 0.1~1.0 is it beneficial to simultaneously maintain the performance of the cell 100 and reduce the damage to the diaphragm caused by penetration welding between the second busbar welding platform 53 and the cell housing 1. The thickness h1 of the first busbar welding platform 52 is set to a constant value.

[0087] Table 4. Experimental table showing the ratio of the thickness h2 of the second busbar welding platform to the thickness h1 of the first busbar welding platform.

[0088]

[0089] Comparative analysis of the experimental examples and comparative examples in Table 4 (Section 1) reveals that when h2:h1 is greater than 1, increasing h2 while keeping h1 constant leads to the busbar 5 occupying more internal space in the cell housing 1, resulting in a significant reduction in the capacity of the cell 100. Comparative analysis of the experimental examples and comparative examples in Table 4 (Section 2) reveals that when h2:h1 is less than 0.1, decreasing h2 while keeping h1 constant leads to a smaller thickness of the second busbar welding platform. This causes the welding process of the second busbar welding platform 53 to burn the diaphragm of the electrode assembly 2 during penetration welding with the cell housing 1, leading to diaphragm shrinkage and ultimately a short circuit inside the electrode assembly 2.

[0090] In some specific embodiments, h2:h1 can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, or any value between any two of the above values, or a range between any two of the above values.

[0091] In some embodiments, h1 ranges from 0.15mm to 1.5mm, and h2 ranges from 0.2mm to 1.2mm, which helps to maintain the battery cell 100 with a suitable capacity, and the second busbar welding platform 53 performs through welding with the battery cell housing 1, and the high heat of welding is unlikely to damage the diaphragm.

[0092] In some specific embodiments, the thickness h1 of the first busbar welding platform 52 can be 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, or any value between any two of the above values, or a range between any two of the above values.

[0093] In some embodiments, the bottom surface of the second busbar welding platform 53 protrudes towards the bottom surface 11 of the cell housing 1 relative to the bottom surface of the first busbar welding platform 52. The height by which the bottom surface of the second busbar welding platform 53 protrudes relative to the bottom surface of the first busbar welding platform 52 is h3, and the thickness of the second busbar welding platform 53 is h2, where h3:h2 = 0.2~1.0. Through experiments analyzing the capacity of the cell 100 and the welding strength after welding the second busbar welding platform 53 to the cell housing 1, the inventors found that only when h3:h2 = 0.2~1.0 is it beneficial to simultaneously maintain the performance of the cell 100 and the welding strength between the second busbar welding platform 53 and the cell housing 1. The thickness h2 of the second busbar welding platform 53 is set to a constant value.

[0094] Table 5. Experimental table showing the ratio of the thickness h2 of the second busbar welding platform to the thickness h1 of the first busbar welding platform.

[0095]

[0096] Comparative analysis of the experimental examples and comparative examples in Table 5 (Section 1) reveals that when h3:h2 > 1, increasing h3 while keeping h2 constant leads to the busbar 5 occupying more internal space in the cell housing 1, resulting in a significant reduction in the capacity of the cell 100. Comparative analysis of the experimental examples and comparative examples in Table 5 (Section 2) reveals that when h3:h2 < 0.2, decreasing h3 while keeping h2 constant leads to a smaller interference fit between the second busbar welding platform 53 and the cell housing 1, resulting in a weak weld between them. After welding and cell assembly, the weld between the second busbar welding platform and the housing tears open, leaving a residual weld area of ​​approximately 20% of the complete weld area.

[0097] In this embodiment of the application, the battery cell 100, after being assembled with the busbar 5, electrode assembly 2 and battery cell housing 1 to form the battery cell 100, is subjected to external forces such as... Figure 6 As shown, regions A and B work together on the busbar, ensuring that the second busbar welding platform 53 is in close contact with the battery cell housing 1, thus improving the reliability of the welding operation.

[0098] 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 battery cell housing (1), characterized in that, include: The base plate (11) has two welding platforms and an explosion-proof platform (15). Both of the welding platforms include a welding surface, and the explosion-proof platform (15) includes a serrated surface (151). The serrated surface (151) has serrations (6). The welding surface and the serrated surface (151) are on different planes.

2. The cell housing (1) according to claim 1, characterized in that, The two welding platforms include a first welding platform (13) and a second welding platform (14). The cell housing (1) is adapted to the cell. The cell includes an electrode assembly (2) located inside the cell housing (1) and a busbar (5) connected to the electrode assembly (2). The electrode assembly (2) is located inside the cell housing (1). The first welding platform (13) includes a first welding surface (131) which is configured to weld to the busbar (5). The second welding platform (14) includes a second welding surface (141) which is adapted to weld to the busbar outside the cell housing (1).

3. The cell housing (1) according to claim 2, characterized in that, The thickness of the first welding platform (13) is a, the thickness of the second welding platform (14) is c, and the thickness of the explosion-proof platform (15) is d, a:c:d=(0.3~1.0):1:(0.3~1).

4. The cell housing (1) according to claim 3, characterized in that, The range of a is 0.3mm to 1.5mm; and / or, the range of c is 0.3mm to 2.0mm; And / or, d ranges from 0.3mm to 1.5mm.

5. The cell housing (1) according to claim 2, characterized in that, The first welding platform (13), the explosion-proof platform (15) and the second welding platform (14) are arranged sequentially along the middle of the base plate (11) towards the side of the base plate (11).

6. The cell housing (1) according to claim 5, characterized in that, The second welding platform (14) includes a first top surface (142) opposite to the second welding surface (141). The first welding surface (131) of the first welding platform (13) protrudes towards the interior of the cell housing (1) relative to the first top surface (142) of the second welding platform (14). The height by which the first welding surface (131) of the first welding platform (13) protrudes relative to the first top surface (142) of the second welding platform (14) is b. The thickness of the first welding platform (13) is a, where b:a = 0.3~1.

0.

7. The cell housing (1) according to claim 5, characterized in that, The explosion-proof platform (15) includes a first bottom surface (152) opposite to the etched surface (151). The first bottom surface (152) protrudes outward from the second welding surface (141) of the second welding platform (14) relative to the outside of the cell housing (1). The height by which the first bottom surface (152) of the explosion-proof platform (15) protrudes from the second welding surface (141) of the second welding platform (14) is e. The thickness of the explosion-proof platform (15) is d, where e:d = 0.3~1.

0.

8. The cell housing (1) according to claim 2, characterized in that, The explosion-proof platform (15), the second welding platform (14) and the first welding platform (13) are arranged sequentially along the side of the base plate away from the center of the base plate.

9. The cell housing (1) according to claim 8, characterized in that, The first welding surface (131) of the first welding platform (13) protrudes towards the interior of the cell housing (1) relative to the etched surface (151) of the explosion-proof platform (15). The height of the protrusion of the first welding surface (131) of the first welding platform (13) relative to the etched surface (151) of the explosion-proof platform (15) is b. The thickness of the first welding platform (13) is a, where b:a = 0.3~1.

0.

10. The cell housing (1) according to claim 8, characterized in that, The second welding platform (14) has a first top surface (142) opposite to the second welding surface (141). The etched surface (151) of the explosion-proof platform (15) protrudes towards the interior of the cell housing (1) relative to the first top surface (142) of the second welding platform (14). The height by which the etched surface (151) of the explosion-proof platform (15) protrudes relative to the first top surface (142) of the second welding platform (14) is e. The thickness of the explosion-proof platform (15) is d, where e:d = 0.3~1.

0.

11. The cell housing (1) according to claim 6 or 9, characterized in that, b ranges from 0.3 mm to 2.0 mm; and / or a ranges from 0.3 mm to 1.5 mm.

12. The cell housing (1) according to claim 7 or 10, characterized in that, The range of e is 0.3mm to 2.0mm; and / or, the range of d is 0.3mm to 1.5mm.

13. The cell housing (1) according to claim 1, characterized in that, The residual thickness at the location of the indentation is f, and f ranges from 0.05 mm to 0.20 mm.

14. A battery cell, characterized in that, The battery cell includes a battery cell housing and an electrode assembly as described in any one of claims 1 to 13, wherein the electrode assembly is disposed within the battery cell housing.

15. The battery cell according to claim 14, characterized in that, The battery cell also includes a busbar (5) located inside the battery cell housing (1), the busbar (5) having a pressure relief hole (51) facing the groove (6).

16. The battery cell according to claim 15, characterized in that, The busbar (5) further includes a first busbar welding platform (52), which is welded to the electrode assembly (2).

17. The battery cell according to claim 16, characterized in that, The busbar (5) also includes a second busbar welding platform (53), which is welded to the battery cell housing (1).

18. The battery cell according to claim 17, characterized in that, The thickness of the first busbar welding platform (52) is h1, and the thickness of the second busbar welding platform (53) is h2, where h2:h1 = 0.1~1.

0.

19. The battery cell according to claim 18, characterized in that, h1 ranges from 0.15mm to 1.5mm; and / or h2 ranges from 0.2mm to 1.2mm.

20. The battery cell according to claim 17, characterized in that, The bottom surface of the second busbar welding platform (53) protrudes outward from the bottom surface of the first busbar welding platform (52) relative to the bottom surface of the battery cell housing (1). The height of the protrusion of the bottom surface of the second busbar welding platform (53) relative to the bottom surface of the first busbar welding platform (52) is h3. The thickness of the second busbar welding platform (53) is h2, and h3:h2=0.2~1.

0.

21. The battery cell according to claim 17, characterized in that, The pressure relief hole (51), the first manifold welding platform (52) and the second manifold welding platform (53) are arranged sequentially along the middle of the manifold (5) and pointing towards the side of the manifold (5).

22. A battery pack, characterized in that, The battery pack includes a housing and a plurality of battery cells located within the housing, wherein the battery cells are configured as described in any one of claims 14 to 21.

23. An electrical appliance, characterized in that, The electrical equipment includes the battery pack as described in claim 22.

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