Casing and cylindrical battery

Abstract

This invention relates to the field of new energy battery technology, and discloses a casing and a cylindrical battery. The casing, used in cylindrical batteries, features high efficiency in housing the cover plate without significant misalignment between the cover plate and the casing body. It also exhibits high welding strength and yield between the cover plate and the casing body, thus improving battery product quality. The casing of this invention includes a casing body and a cover plate. At least one end of the casing body is an open end. The cover plate is disposed on the open end and includes a body portion and a protrusion. The protrusion is located on the side of the body portion facing the casing body, and at least partially within the casing body. The side of the body portion facing the casing body is connected to the end face of the open end. The outer circumferential surface area of ​​the body portion perpendicular to the axial direction of the cover plate is S1, the outer circumferential surface area of ​​the protrusion perpendicular to the axial direction of the cover plate is S2, and the inner circumferential surface area of ​​the casing perpendicular to the axial direction of the casing is S3, where S2 ≤ S3, satisfying 1250 mm. 2 ≤S1 / (S2 / S3)≤2000mm 2 .

Description

Technical Field

[0001] This invention relates to the field of new energy battery technology, specifically to a casing and a cylindrical battery. Background Technology

[0002] Cylindrical batteries are characterized by their cylindrical physical shape. The outer casing is typically made of metal (such as steel or aluminum), and the internal components—positive electrode, negative electrode, and separator—are wound into a core and then packaged. The standardized design of cylindrical batteries gives them high manufacturing efficiency and adaptability, making them one of the mainstream packaging forms for new energy batteries.

[0003] The casing of a cylindrical battery mainly consists of a housing and a cover plate. The cover plate is welded to the open end of the housing to seal the housing. However, after the cover plate and housing are installed together, the cover plate is prone to being offset to one side relative to the housing, causing serious misalignment of the cover plate. This affects the welding strength and yield of the cover plate to the open end of the housing, and consequently affects the product quality of the cylindrical battery. Summary of the Invention

[0004] In view of this, the present invention provides a cylindrical battery casing to solve the problem that the cover plate of the existing cylindrical battery tends to be biased to one side after being installed in the casing, which affects the welding strength between the cover plate and the casing and the battery quality.

[0005] In a first aspect, the present invention provides a housing, comprising:

[0006] The shell body has at least one open end;

[0007] A cover plate is provided on the opening end. The cover plate includes a body part and a protrusion part. The protrusion part is disposed on the side of the body part facing the shell body. The protrusion part is at least partially placed inside the shell body. The side of the body part facing the shell body is connected to the end face of the opening end.

[0008] The outer circumferential surface area of ​​the main body perpendicular to the axial direction of the cover plate is S1, the outer circumferential surface area of ​​the protrusion perpendicular to the axial direction of the cover plate is S2, and the inner circumferential surface area of ​​the shell body perpendicular to the axial direction of the shell body is S3, where S2 ≤ S3, satisfying: 1250mm. 2 ≤S1 / (S2 / S3)≤2000mm 2 .

[0009] Beneficial Effects: The shell of the present invention includes a shell body and a cover plate. The cover plate covers the open end of the shell body. The cover plate includes a body portion and a protrusion portion. The outer peripheral surface area of ​​the body portion perpendicular to the axial direction of the cover plate is S1, the outer peripheral surface area of ​​the protrusion portion perpendicular to the axial direction of the cover plate is S2, and the inner peripheral surface area of ​​the shell body perpendicular to the axial direction of the shell body is S3. In the present invention, the numerical range of "S1 / (S2 / S3)" is 1250 mm. 2 ≤S1 / (S2 / S3)≤2000mm2 Within the above-mentioned value range, the protrusion of the cover plate is easier to insert into the shell body, which facilitates the installation of the cover plate into the shell, reduces the assembly difficulty, and improves the efficiency of the cover plate installation. Moreover, after the cover plate is installed into the shell body, the offset of the cover plate relative to the shell body is small, and the cover plate can be set more centrally. The contact area between the cover plate body and the opening end face of the shell body is larger and the contact area distribution is more uniform, which can ensure the welding strength and welding yield between the cover plate and the shell body, thereby improving the overall product quality of the cylindrical battery.

[0010] In a second aspect, the present invention provides a cylindrical battery, comprising a casing as described above.

[0011] Since the cylindrical battery of the present invention includes the casing of the present invention and has the same beneficial effects as the casing, it will not be described in detail here. Attached Figure Description

[0012] 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.

[0013] Figure 1 This is an overall schematic diagram of the cylindrical battery of the present invention;

[0014] Figure 2 This is an exploded view of the cylindrical battery of the present invention (only the casing and cover plate are retained).

[0015] Figure 3 This is a cross-sectional view of the cylindrical battery of the present invention;

[0016] Figure 4 for Figure 3 An enlarged schematic diagram of part A in the middle;

[0017] Figure 5 This is a side view of the cover of the cylindrical battery of the present invention;

[0018] Figure 6 for Figure 5 Enlarged schematic diagram of part B;

[0019] Figure 7 This is a schematic diagram of the various positions on the protrusion in this invention;

[0020] Figure 8 This is a three-dimensional schematic diagram of the cover body of the cylindrical battery of the present invention;

[0021] Figure 9 This is a bottom view of the cover of the cylindrical battery of the present invention;

[0022] Figure 10 This is a schematic diagram showing the dimensions of the casing and cover of the cylindrical battery of the present invention.

[0023] Explanation of reference numerals in the attached figures:

[0024] 1. Shell body; 101. Open end;

[0025] 2. Cover plate; 201. Body part; 202. Protrusion; 203. Protrusion. Detailed Implementation

[0026] 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.

[0027] Currently, the cylindrical batteries on the market mainly consist of a casing and a cover plate. At least one end of the casing is open, and the cover plate is adapted to cover this open end. The side of the cover plate facing the casing is welded to the end face of the open end to seal the cylindrical battery casing. The side of the cover plate facing the casing has a boss structure. During assembly, the boss enters the casing, and there is a gap between the outer circumferential wall of the boss and the inner circumferential wall of the casing to facilitate the installation of the cover plate. However, if this gap is too large, the center of the cover plate may deviate too much from the center of the casing after installation, causing the cover plate to be significantly biased to one side (e.g., the left side). In this case, the contact area (welding area) between the side of the cover plate facing the casing and the end face of the open end will be reduced on the other side (e.g., the right side). During welding, the weld strength between the cover plate and the casing will be insufficient, affecting the welding yield and consequently the overall quality of the cylindrical battery.

[0028] Based on this, the present invention provides a cylindrical battery with high welding strength between the cover plate and the shell, good yield, and guaranteed product quality.

[0029] The following is combined with Figures 1 to 10 This describes embodiments of the casing and cylindrical battery of the present invention.

[0030] According to an embodiment of the present invention, a housing for a cylindrical battery is provided. The housing includes a housing body 1 and a cover plate 2, wherein at least one end of the housing body 1 is an open end 101; the cover plate 2 covers the open end 101, and the cover plate 2 includes a body portion 201 and a protrusion 202, the protrusion 202 being disposed on the side of the body portion 201 facing the housing body 1, the protrusion 202 being at least partially disposed inside the housing body 1, and the side of the body portion 201 facing the housing body 1 being connected to the end face of the open end 101; the outer peripheral surface area of ​​the body portion 201 perpendicular to the axial direction of the cover plate 2 is S1, the outer peripheral surface area of ​​the protrusion 202 perpendicular to the axial direction of the cover plate 2 is S2, and the inner peripheral surface area of ​​the housing body 1 perpendicular to the axial direction of the housing body 1 is S3, where S2 ≤ S3, satisfying: 1250 mm. 2 ≤S1 / (S2 / S3)≤2000mm 2 .

[0031] This type of housing is controlled by adjusting the numerical range of "S1 / (S2 / S3)", which is 1250mm. 2 ≤S1 / (S2 / S3)≤2000mm 2 This design allows the protrusion 202 of the cover plate 2 to be easily inserted into the shell body 1, facilitating the installation of the cover plate 2 and reducing assembly difficulty (difficulty of insertion). It also improves the efficiency of the cover plate 2's insertion into the shell. Furthermore, after the cover plate 2 is inserted into the shell body 1, the offset of the cover plate 2 relative to the shell body 1 is small, allowing the cover plate 2 to be more centrally positioned. The contact area between the body portion 201 of the cover plate 2 and the opening end 101 of the shell body 1 is larger and the contact area distribution is more uniform, ensuring the welding strength and welding yield between the cover plate 2 and the shell body 1, thereby improving the overall product quality of the cylindrical battery.

[0032] It should be noted that weld strength is judged by whether the effective weld penetration (0.35mm) and effective weld width (0.6mm) after welding the cover plate and the shell body are greater than the standard values. If they are greater than the standard values, the weld strength meets the requirements; if they are less than the standard values, the weld strength is insufficient. The ease of insertion into the shell is judged based on whether the cover plate can be inserted into the shell body under an insertion pressure of 100N. If the cover plate can be inserted into the shell body, insertion is not difficult; if the cover plate cannot be inserted into the shell body, insertion is difficult.

[0033] like Figures 1-2 As shown, the cylindrical battery is cylindrical in shape overall. Figure 1 In the diagram, the x-direction is the radial direction of the cylindrical battery (the radial direction of the casing), and the y-direction is the axial direction of the cylindrical battery (the axial direction of the casing).

[0034] The casing includes a casing body 1 and a cover plate 2. The casing body 1 and the cover plate 2, when fitted together, form the casing of the cylindrical battery. The casing body 1 is cylindrical and has two ends along the axial direction of the cylindrical battery. Figure 1Taking a perspective example, the casing body 1 has an upper end and a lower end. At least one end of the casing body 1 is an open end 101, that is, both the upper and lower ends of the casing body 1 are open ends 101, or only the upper end of the casing body 1 is an open end 101, or only the lower end of the casing body 1 is an open end 101. In this embodiment, the upper end of the casing body 1 is an open end 101. The cover plate 2 cooperates with the casing body 1, and the cover plate 2 is adapted to cover the open end 101 to seal the casing and ensure the performance of the cylindrical battery.

[0035] The shell body 1 can be made of aluminum or aluminum alloy, such as aluminum-manganese alloy, aluminum-magnesium alloy, etc.; or the shell body 1 can be made of steel, such as stainless steel, carbon steel, nickel-plated steel, titanium, etc. The cover plate 2 can be made of the same material as the shell body 1.

[0036] The sidewall of the shell body 1 has a certain thickness. The outer wall of the shell body 1 is the outer cylindrical surface of the cylindrical battery shell. The inner wall of the shell body 1 surrounds the shell body 1 to form an accommodating space. The cylindrical battery core and other structural components are placed in this accommodating space.

[0037] A wound core, also known as a battery cell, is a battery cell body formed by winding a positive electrode plate, a negative electrode plate, and a separator placed between them.

[0038] The positive electrode sheet includes a positive current collector and a positive active material. The positive current collector can be made of metal materials such as aluminum foil, nickel foil, and stainless steel, or it can be a composite foil formed by combining metals and insulating materials. The positive active material includes the main positive active material, conductive agent, binder, etc. The main positive active material includes one or more lithium-containing positive active materials such as lithium iron phosphate, ternary materials containing nickel, cobalt, and manganese, and lithium manganese iron phosphate.

[0039] The negative electrode sheet includes a negative electrode current collector and a negative electrode active material. The negative electrode current collector can be made of metal materials such as copper foil, aluminum foil, and stainless steel, or it can be a composite foil formed by combining metals and insulating materials. The negative electrode active material includes the negative electrode active material, conductive agent, binder, etc. The negative electrode active material includes one or more of the following: artificial graphite, natural graphite, silicon carbide, silicon oxide, lithium titanate, etc.

[0040] In this embodiment, the radial direction of the shell body 1 is the same as the radial direction of the cylindrical battery. Figure 1 (in the x-direction), the axial direction of the shell body 1 is the axial direction of the cylindrical battery. Figure 1 middle y direction).

[0041] like Figures 5-9 As shown, the cover plate 2 includes a body portion 201 and a protrusion 202. The body portion 201 is located away from the shell body 1 relative to the protrusion 202. Figure 1 and Figure 2Taking the cylindrical battery as an example, along the axial direction of the cylindrical battery, the main body 201 is located at the upper part of the cover plate 2, and the protrusion 202 is located at the lower part of the cover plate 2. The protrusion 202 is disposed on the side of the main body 201 facing the shell body 1, and the protrusion 202 protrudes from the side of the main body 201 facing the shell body 1. In this embodiment, the protrusion 202 is a boss. It can be understood that, in order to facilitate the fit between the cover plate 2 and the shell body 1, and to facilitate the forming of the cover plate 2, both the main body 201 and the protrusion 202 are cylindrical structures with relatively small axial heights. Optionally, the axial center of the cover plate 2 is the same as the axial center of the main body 201 and the protrusion 202. Simultaneously, the radial direction of the cover plate 2 is the same as the radial direction of the cylindrical battery. Figure 1 (in the x direction), the axial direction of cover plate 2 is the axial direction of the cylindrical battery. Figure 1 middle y direction).

[0042] Both the main body 201 and the protrusion 202 are cylindrical structures, and the cross-sections of both the main body 201 and the protrusion 202 perpendicular to the axial direction are circular. To facilitate the insertion of the protrusion 202 into the shell body 1 and the connection between the main body 201 and the end face of the opening 101, the radius of the circular surface of the protrusion 202 perpendicular to the axial direction is smaller than the radius of the circular surface of the main body 201 perpendicular to the axial direction. The radius of the circular surface of the protrusion 202 perpendicular to the axial direction is also smaller than the radius of the inner wall of the shell body 1, while the radius of the circular surface of the main body 201 perpendicular to the axial direction is larger than the radius of the inner wall of the shell body 1.

[0043] like Figures 3-4 As shown, when the cover plate 2 is placed over the opening end 101 of the shell body 1, the protrusion 202 is at least partially placed inside the shell body 1. The side of the body portion 201 facing the shell body 1 contacts the end face of the opening end 101, and subsequently, the side of the body portion 201 facing the shell body 1 is connected to the end face of the opening end 101 to seal the shell of the cylindrical battery. In this embodiment, the connection between the side of the body portion 201 facing the shell body 1 and the end face of the opening end 101 is by welding. When the side of the body portion 201 facing the shell body 1 is not welded to the end face of the opening end 101, the protrusion 202 is entirely placed inside the shell body 1. After the side of the body portion 201 facing the shell body 1 is welded to the end face of the opening end 101, due to the thickness of the solder, some of the protrusion 202 is placed outside the shell body 1, but at this time, most of the protrusion 202 is still placed inside the shell body 1. After the cover plate 2 is placed on the opening end 101 of the shell body 1, there is a certain gap between the outer wall of the protrusion 202 and the inner wall of the shell body 1, so that the protrusion 202 of the cover plate 2 can be easily inserted into the shell body 1, thereby realizing the shell assembly of the cover plate 2.

[0044] In addition, when the cover plate 2 is placed on the opening end 101 of the shell body 1, the edge of the body part 201 facing the shell body 1 overlaps the end face of the opening end 101 between the inner wall and the outer wall of the shell body 1. From the top view, the inner wall of the shell body 1 is located inside the outer wall of the body part 201, while the outer wall of the shell body 1 is flush with the outer wall of the body part 201, and the two are located on the same arc surface.

[0045] like Figure 10 As shown, the area of ​​the outer peripheral surface of the main body 201 perpendicular to the axial direction of the cover plate 2 is S1, the area of ​​the outer peripheral surface of the protrusion 202 perpendicular to the axial direction of the cover plate 2 is S2, and the area of ​​the inner peripheral surface of the shell body 1 perpendicular to the axial direction of the shell body 1 is S3.

[0046] Specifically, the cross section of the main body 201 perpendicular to the axial direction of the cover plate 2 is a circular surface. The outer edge of the main body 201 (the outer edge of the main body 201 extends along the axial direction of the cover plate 2 to form the outer wall of the main body 201) forms this circular surface, and the area of ​​this circular surface is the area S1 of the outer peripheral surface of the main body 201 perpendicular to the axial direction of the cover plate 2.

[0047] Similarly, the cross section of the protrusion 202 perpendicular to the axial direction of the cover plate 2 is a circular surface. The outer edge of the protrusion 202 (the outer edge of the protrusion 202 extends along the axial direction of the cover plate 2 to form the outer wall of the protrusion 202) forms this circular surface, and the area of ​​this circular surface is the area S2 of the outer peripheral surface of the protrusion 202 perpendicular to the axial direction of the cover plate 2.

[0048] Similarly, the inner wall of the shell body 1 has a circular cross-section perpendicular to the axial direction of the shell body 1. The inner edge of the shell body 1 (the inner edge of the shell body 1 extends along the axial direction of the shell body 1 to form the inner wall of the shell body 1) forms this circular surface. The area of ​​this circular surface is the area S3 of the inner circumferential surface of the shell body 1 perpendicular to the axial direction of the shell body 1.

[0049] Furthermore, since the protrusion 202 is located on the inner side of the inner wall of the shell body 1, the area S2 of the outer peripheral surface of the protrusion 202 perpendicular to the axial direction of the cover plate 2 is smaller than the area S3 of the inner peripheral surface of the shell body 1 perpendicular to the axial direction of the shell body 1, that is, S2≤S3.

[0050] In this embodiment, the relationship between S1, S2, and S3 satisfies: 1250mm 2 ≤S1 / (S2 / S3)≤2000mm 2Within the aforementioned range, the protrusion 202 of the cover plate 2 is more easily inserted into the shell body 1, facilitating the installation of the cover plate 2 into the shell, reducing assembly difficulty, and improving the efficiency of the cover plate 2's installation. Moreover, after the cover plate 2 is installed into the shell body 1, the gap between the outer wall of the protrusion 202 and the inner wall of the shell body 1 is not too large, the offset of the cover plate 2 relative to the shell body 1 is small, the cover plate 2 is more centrally positioned, and the contact area between the body portion 201 and the end face of the opening end 101 is larger and the contact area distribution is more uniform, ensuring the welding strength and welding yield between the cover plate 2 and the shell body 1, thereby improving the overall product quality of the cylindrical battery.

[0051] For example, the value of "S1 / (S2 / S3)" can be 1250mm. 2 1300mm 2 1620mm 2 1945mm 2 2000mm 2 wait.

[0052] Furthermore, the area S1 of the outer peripheral surface of the main body 201 perpendicular to the axial direction of the cover plate 2 ranges from 1200 mm. 2 -2000mm 2 .

[0053] The cross-section of the main body 201 perpendicular to the axial direction of the cover plate 2 is a circular surface, and the area of ​​this circular surface is the area S1 of the outer peripheral surface of the main body 201 perpendicular to the axial direction of the cover plate 2.

[0054] In this embodiment, the area S1 ranges from 1200 mm². 2 -2000mm 2 Within the above-mentioned range, the area S1 will not be too large or too small, which can ensure that the roundness of the body part 201 is good, reduce the processing difficulty, make the welding area of ​​the body part 201 facing the shell body 1 and the end face of the opening end 101 uniform and consistent, and the size of the welding area meets the requirements, thereby ensuring the welding strength and welding yield of the two.

[0055] For example, the area S1 can be 1200 mm². 2 1460mm 2 1760mm 2 1870mm 2 1910mm 2 2000mm 2 wait.

[0056] Furthermore, the area S2 of the outer peripheral surface of the protrusion 202 perpendicular to the axial direction of the cover plate 2 ranges from 1100 mm. 2 -2000mm 2 .

[0057] The cross-section of the protrusion 202 perpendicular to the axial direction of the cover plate 2 is a circular surface, and the area of ​​this circular surface is the area S2 of the outer peripheral surface of the protrusion 202 perpendicular to the axial direction of the cover plate 2.

[0058] In this embodiment, the area S2 ranges from 1100 mm². 2 -2000mm 2 Within the aforementioned value range, the area S2 will not be too large or too small, allowing the protrusion 202 to be easily inserted into the shell body 1, ensuring the efficiency of the cover plate 2's insertion into the shell and reducing assembly difficulty. At the same time, after the cover plate 2 is placed on the opening end 101 of the shell body 1, the gap between the outer wall of the protrusion 202 and the inner wall of the shell body 1 will not be too large, and the cover plate 2 will not have serious misalignment problems. This ensures that the welding area of ​​the body part 201 facing the shell body 1 and the end face of the opening end 101 is uniform and consistent, and the size of the welding area meets the requirements, thereby ensuring the welding strength and welding yield of both.

[0059] For example, the area S2 can be 1100 mm². 2 1350mm 2 1460mm 2 1680mm 2 1920mm 2 2000mm 2 wait.

[0060] Furthermore, the value range of the inner circumferential surface area S3 of the shell body 1 perpendicular to the axial direction of the shell body 1 is 1200 mm. 2 -2000mm 2 .

[0061] The inner wall of the shell body 1 has a circular cross-section perpendicular to its axial direction. The area of ​​this circular surface is the area S3 of the inner circumferential surface of the shell body 1 perpendicular to its axial direction. If the area S3 is too large, the gap between the outer wall of the protrusion 202 and the inner wall of the shell body 1 will be too large after the protrusion 202 is inserted into the shell body 1. This can easily cause severe misalignment of the cover plate 2 relative to the shell body 1, resulting in uneven welding areas between the side of the body part 201 facing the shell body 1 and the end face of the opening end 101. This can lead to insufficient welding strength and low welding yield. If the area S3 is too small, it will be difficult to insert the protrusion 202 into the shell body 1, affecting the efficiency of the cover plate 2's insertion into the shell and increasing the assembly difficulty.

[0062] In this embodiment, the area S3 ranges from 1200 mm². 2 -2000mm 2Within the aforementioned value range, the area S3 will not be too large or too small, allowing the protrusion 202 to be easily inserted into the shell body 1, ensuring the efficiency of the cover plate 2's insertion into the shell and reducing assembly difficulty. At the same time, after the cover plate 2 is placed on the opening end 101 of the shell body 1, the gap between the outer wall of the protrusion 202 and the inner wall of the shell body 1 will not be too large, and the cover plate 2 will not have serious misalignment problems. This ensures that the welding area of ​​the body part 201 facing the shell body 1 and the end face of the opening end 101 is uniform and consistent, and the size of the welding area meets the requirements, thereby ensuring the welding strength and welding yield of both.

[0063] For example, the area S3 can be 1200 mm². 2 1370mm 2 1550mm 2 1720mm 2 1880mm 2 2000mm 2 wait.

[0064] Furthermore, the ratio between the outer peripheral surface area S2 of the protrusion 202 perpendicular to the axial direction of the cover plate 2 and the inner peripheral surface area S3 of the shell body 1 perpendicular to the axial direction of the shell body 1 is in the range of 0.95-1.

[0065] The ratio of area S2 to area S3 is related to the fit between the outer wall of the protrusion 202 and the inner wall of the shell body 1. If the value of "S2 / S3" is too large, the area S2 will be too large or the area S3 will be too small, making it difficult for the protrusion 202 to be inserted into the shell body 1, affecting the efficiency of the cover plate 2's insertion into the shell and increasing the assembly difficulty. If the value of "S2 / S3" is too small, the area S2 will be too small or the area S3 will be too large, resulting in an excessive gap between the outer wall of the protrusion 202 and the inner wall of the shell body 1 after the protrusion 202 is inserted into the shell body 1. This can easily cause severe misalignment of the cover plate 2 relative to the shell body 1, resulting in uneven welding areas on the side of the body 201 facing the shell body 1 and the end face of the opening end 101, making it impossible to guarantee welding strength and resulting in low welding yield.

[0066] In this embodiment, the ratio of "S2 / S3" ranges from 0.95 to 1. Within this range, the value of "S2 / S3" will not be too large or too small, allowing the protrusion 202 to be easily inserted into the shell body 1, ensuring the efficiency of the cover plate 2's insertion into the shell and reducing assembly difficulty. At the same time, after the cover plate 2 is placed on the opening end 101 of the shell body 1, the gap between the outer wall of the protrusion 202 and the inner wall of the shell body 1 will not be too large, preventing the cover plate 2 from experiencing severe misalignment. This ensures that the welding area of ​​the body part 201 facing the shell body 1 and the end face of the opening end 101 is uniform and consistent, and the size of the welding area meets the requirements, thereby guaranteeing the welding strength and welding yield of both.

[0067] For example, the ratio of "S2 / S3" can be 0.95, 0.96, 0.97, 0.98, 0.99, 1, etc.

[0068] Furthermore, along the radial direction of the cover plate 2, the distance from one side of the outer wall of the protrusion 202 to the inner wall of the shell body 1 is L1, and the distance from the other side of the outer wall of the protrusion 202 to the inner wall of the shell body 1 is L2, satisfying: 0.6≤L1 / L2≤1.4.

[0069] like Figure 1 As shown, the radial direction of the cover plate 2 is the x-direction. When the cover plate 2 is placed over the opening end 101, there is a certain gap between the outer wall of the protrusion 202 and the inner wall of the shell body 1. Furthermore, in the x-direction, the distance from one side of the outer wall of the protrusion 202 to the inner wall of the shell body 1 is L1, and the distance from the other side of the outer wall of the protrusion 202 to the inner wall of the shell body 1 is L2. For example, with... Figure 3 , Figure 4 Taking a perspective example, the distance from the left outer wall of the protrusion 202 to the inner wall of the shell body 1 is L1, and the distance from the right outer wall of the protrusion 202 to the inner wall of the shell body 1 is L2; ​​of course, it is also possible that the distance from the right outer wall of the protrusion 202 to the inner wall of the shell body 1 is L1, and the distance from the left outer wall of the protrusion 202 to the inner wall of the shell body 1 is L2.

[0070] If the L1 / L2 ratio is too large or too small, the difference between distances L1 and L2 will be too great, which can easily cause severe misalignment of the cover plate 2 relative to the shell body 1. This will result in uneven welding areas on the side of the body part 201 facing the shell body 1 and the end face of the opening end 101, making it impossible to guarantee welding strength and resulting in low welding yield. If the L1 / L2 ratio is too small, it will require higher processing technology, increasing the difficulty of the process and increasing processing costs.

[0071] In this embodiment, the ratio of distance L1 to distance L2 is within the range of 0.6 ≤ L1 / L2 ≤ 1.4. Within this range, the ratio of distance L1 to distance L2 is neither too large nor too small; the values ​​of distance L1 and distance L2 are close and the difference between them is small. After the cover plate 2 is placed on the opening end 101 of the shell body 1, the cover plate 2 is relatively centrally positioned, avoiding serious misalignment. This ensures that the welding area of ​​the body part 201 facing the shell body 1 and the end face of the opening end 101 is uniform and consistent, and the size of the welding area meets the requirements, thereby guaranteeing the welding strength and welding yield. Moreover, the process is less difficult, which is beneficial for controlling processing costs.

[0072] For example, the ratio of "L1 / L2" can be 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, etc.

[0073] Furthermore, along the radial direction of the cover plate 2, the distance from one side of the outer wall of the protrusion 202 to the inner wall of the shell body 1 is L1, and the distance from the other side of the outer wall of the protrusion 202 to the inner wall of the shell body 1 is L2. The value range of L1 is 0.02mm-0.5mm, and the value range of L2 is 0.02mm-0.5mm.

[0074] like Figure 1 As shown, the radial direction of the cover plate 2 is the x-direction. When the cover plate 2 is placed over the opening end 101, there is a certain gap between the outer wall of the protrusion 202 and the inner wall of the shell body 1. Furthermore, in the x-direction, the distance from one side of the outer wall of the protrusion 202 to the inner wall of the shell body 1 is L1, and the distance from the other side of the outer wall of the protrusion 202 to the inner wall of the shell body 1 is L2.

[0075] If the distance L1 is too large, the gap between the outer wall of the protrusion 202 and the inner wall of the shell body 1 at that position will be too large, which will easily cause the cover plate 2 to be severely misaligned relative to the shell body 1. This will result in an uneven welding area between the side of the body part 201 facing the shell body 1 and the end face of the opening end 101, making it impossible to guarantee the welding strength and resulting in a low welding yield. If the distance L1 is too small, it will be difficult to insert the protrusion 202 into the shell body 1, affecting the efficiency of the cover plate 2 entering the shell and increasing the assembly difficulty.

[0076] In this embodiment, the distance L1 ranges from 0.02mm to 0.5mm. Within this range, the distance L1 is neither too large nor too small, allowing the protrusion 202 to be easily inserted into the shell body 1, ensuring the efficiency of the cover plate 2's insertion into the shell and reducing assembly difficulty. At the same time, after the cover plate 2 is placed on the opening end 101 of the shell body 1, the gap between the outer wall of the protrusion 202 and the inner wall of the shell body 1 is not too large, and the cover plate 2 will not have serious misalignment. This ensures that the welding area of ​​the body part 201 facing the shell body 1 and the end face of the opening end 101 is uniform and consistent, and the size of the welding area meets the requirements, thereby ensuring the welding strength and welding yield of both.

[0077] For example, the distance L1 can be 0.02mm, 0.04mm, 0.1mm, 0.24mm, 0.3mm, 0.46mm, 0.5mm, etc.

[0078] Similarly, if the distance L2 is too large, the gap between the outer wall of the protrusion 202 and the inner wall of the shell body 1 at that position will be too large, which will easily cause the cover plate 2 to be severely misaligned relative to the shell body 1. This will result in an uneven welding area between the side of the body part 201 facing the shell body 1 and the end face of the opening end 101, making it impossible to guarantee the welding strength and resulting in a low welding yield. If the distance L2 is too small, it will be difficult to insert the protrusion 202 into the shell body 1, affecting the efficiency of the cover plate 2 entering the shell and increasing the assembly difficulty.

[0079] In this embodiment, the distance L2 is in the range of 0.02mm-0.5mm. Within this range, the distance L2 is neither too large nor too small, allowing the protrusion 202 to be easily inserted into the shell body 1, ensuring the efficiency of the cover plate 2's insertion into the shell and reducing assembly difficulty. At the same time, after the cover plate 2 is placed on the opening end 101 of the shell body 1, the gap between the outer wall of the protrusion 202 and the inner wall of the shell body 1 is not too large, and the cover plate 2 will not have serious misalignment. This ensures that the welding area of ​​the body part 201 facing the shell body 1 and the end face of the opening end 101 is uniform and consistent, and the size of the welding area meets the requirements, thereby ensuring the welding strength and welding yield of both.

[0080] For example, the distance L2 can be 0.02mm, 0.05mm, 0.12mm, 0.26mm, 0.35mm, 0.43mm, 0.5mm, etc.

[0081] Furthermore, along the radial direction of the cover plate 2, the distance from one side of the outer wall of the protrusion 202 to the inner wall of the shell body 1 is L1, and the distance from the other side of the outer wall of the protrusion 202 to the inner wall of the shell body 1 is L2, and L1 = L2, satisfying: 1700mm 2 ≤S1 / (S2 / S3)≤2000mm 2 .

[0082] In the x-direction, the distance from one outer wall of the protrusion 202 to the inner wall of the shell body 1 is L1, and the distance from the other outer wall of the protrusion 202 to the inner wall of the shell body 1 is L2. In this embodiment, L1 = L2. When the cover plate 2 is placed on the shell body 1, the protrusion 202 is centrally located, and the gap between the outer wall of the protrusion 202 and the inner wall of the shell body 1 is uniform in the circumferential direction. At this time, the area S2 and the area S3 can be relatively close, that is, "S2 / S3" can be smaller, thus satisfying: 1700mm. 2 ≤S1 / (S2 / S3)≤2000mm 2 It can still ensure that the protrusion 202 can be easily inserted into the shell body 1, and the assembly difficulty is low. The cover plate 2 has a high shell insertion efficiency. Moreover, the cover plate 2 is centered relative to the shell body 1. The welding area of ​​the body part 201 facing the shell body 1 and the end face of the opening end 101 is uniform and consistent, and the size of the welding area meets the requirements, thereby ensuring the welding strength and welding yield of the two.

[0083] For example, "S1 / (S2 / S3)" can be 1700mm. 2 1910mm 2 2000mm 2 wait.

[0084] In other embodiments, along the radial direction of the cover plate 2, the distance from one outer wall of the protrusion 202 to the inner wall of the shell body 1 is L1, and the distance from the other outer wall of the protrusion 202 to the inner wall of the shell body 1 is L2, and L1 > L2 or L1 < L2, satisfying: 1250mm 2 ≤S1 / (S2 / S3)≤1650mm 2 To meet different configuration requirements.

[0085] In this embodiment, distance L1 is not equal to distance L2. The cover plate 2 is significantly misaligned relative to the shell body 1, and the gap between the outer wall of the protrusion 202 and the inner wall of the shell body 1 is uneven. In this case, "S2 / S3" needs to be larger to avoid insufficient welding strength at locations with a larger gap between the outer wall of the protrusion 202 and the inner wall of the shell body 1, i.e., satisfying 1250mm. 2 ≤S1 / (S2 / S3)≤1650mm 2 Within this range, it can be ensured that the protrusion 202 can be easily inserted into the shell body 1, the assembly difficulty is low, the cover plate 2 has a high shell insertion efficiency, and the welding area of ​​the body part 201 facing the shell body 1 and the end face of the opening end 101 is as large and uniform as possible to ensure the welding strength and welding yield of the two.

[0086] For example, "S1 / (S2 / S3)" can be 1250mm. 2 1340mm 2 1490mm 2 1570mm 2 1650mm 2 wait.

[0087] Furthermore, along the axial direction of the cover plate 2, the height of the protrusion 202 inside the shell body 1 is H, and the value of H ranges from 0.2mm to 2mm.

[0088] The protrusion 202 is a cylindrical structure with a certain axial height, and the axial direction of the protrusion 202 is the same as the axial direction of the cover plate 2. Figure 1 (As shown in the y-direction). After the protrusion 202 is inserted into the shell body 1, the protrusion 202 is placed inside the shell body 1, and its height is H, as shown. Figure 6 As shown.

[0089] If the height H of the protrusion 202 is too high, the operation time when the protrusion 202 is inserted into the shell body 1 will be longer, resulting in low efficiency of the cover plate 2 entering the shell. If the height H of the protrusion 202 is too low, after the protrusion 202 is inserted into the shell body 1, the protrusion 202 is easy to come out of the shell body 1, making it difficult to position the cover plate 2 and the shell body 1, affecting the assembly.

[0090] In this embodiment, the height H of the protrusion 202 ranges from 0.2mm to 2mm. Within this range, the height H of the protrusion 202 is neither too high nor too low, which facilitates the rapid insertion of the protrusion 202 into the shell body 1, improving the efficiency of the cover plate 2's insertion into the shell. Simultaneously, after the protrusion 202 is inserted into the shell body 1, the cover plate 2 and the shell body 1 can be reliably positioned, facilitating subsequent welding operations and improving assembly efficiency.

[0091] For example, the height of the protrusion 202 can be 0.2mm, 0.5mm, 0.8mm, 1.2mm, 1.6mm, 1.8mm, 2mm, etc.

[0092] Furthermore, the outer wall of the protrusion 202 is provided with a protrusion 203, which is arranged in the radial direction. At least a portion of the outer wall of the protrusion 203 abuts against the inner wall of the shell body 1, satisfying: 1500mm. 2 ≤S1 / (S2 / S3)≤2000mm 2 .

[0093] like Figures 5-9 As shown, the outer wall of the protrusion 202 is provided with a protrusion 203, which protrudes from the outer wall of the protrusion 202 and is arranged in a radial direction. At least a portion of the outer wall of the protrusion 203 abuts against the inner wall of the shell body 1. That is, at least a portion of the outer wall of the protrusion 202 does not directly contact the inner wall of the shell body 1, but contacts the inner wall of the shell body 1 through the protrusion 203. In this embodiment, the entire outer wall of the protrusion 202 does not directly contact the inner wall of the shell body 1; the entire outer wall of the protrusion 202 abuts against the inner wall of the shell body 1 through the protrusion 203.

[0094] When the protrusion 202 is inserted into the shell body 1, the outer wall of the protrusion 203 abuts against the inner wall of the shell body 1. By setting the protrusion 203 and having its outer wall abut against the inner wall of the shell body 1, the protrusion 202 is more easily centered, thereby centering the cover plate 2 relative to the shell body 1, which satisfies the requirement of 1500mm. 2 ≤S1 / (S2 / S3)≤2000mm 2 Within the above-mentioned range of values, the protrusion 202 can be inserted into the shell body 1 more easily, further reducing the assembly difficulty and improving the efficiency of the cover plate 2 entering the shell. Moreover, the welding area of ​​the body part 201 facing the shell body 1 and the end face of the opening end 101 is as large and uniform as possible to ensure the welding strength and welding yield of the two.

[0095] For example, "S1 / (S2 / S3)" can be 1500mm. 2 1650mm 2 1760mm 2 1880mm 21940mm 2 2000mm 2 wait.

[0096] In other embodiments, the outer wall of the protrusion 203 may abut against the inner wall of the shell body 1. In this case, part of the outer wall of the protrusion 202 abuts against the inner wall of the shell body 1 through the protrusion 203.

[0097] Furthermore, along the circumference of the protrusion 202, at least two protrusions 203 are provided, and the at least two protrusions 203 are spaced apart. The ratio between the outer circumferential surface area S2 of the protrusion 202 perpendicular to the axial direction of the cover plate 2 and the inner circumferential surface area S3 of the shell body 1 perpendicular to the axial direction of the shell body 1 is in the range of 0.97-1.

[0098] Protrusions 203 are disposed on the outer wall of the protrusion 202. Depending on different requirements, protrusions 203 can be continuous or discontinuous. In this embodiment, protrusions 203 are discontinuous, and at least two protrusions 203 are provided, for example, two, three, four, six, etc. At least two protrusions 203 are spaced apart, and the specific number of protrusions 203 can be selected according to the circumference of the protrusion 202. Specifically, in this embodiment, eight protrusions 203 are provided, with adjacent protrusions 203 spaced apart.

[0099] Optionally, the spacing between adjacent protrusions 203 is the same in the circumferential direction, so that the position of the cover plate 2 relative to the shell body 1 is more centered, and the welding area of ​​the body part 201 facing the shell body 1 and the end face of the opening end 101 is uniform, so as to ensure the welding strength and welding yield of the two.

[0100] This protrusion 203 arrangement facilitates easy installation into the shell. The ratio of the outer circumferential surface area S2 of the protrusion 202 perpendicular to the axial direction of the cover plate 2 to the inner circumferential surface area S3 of the shell body 1 perpendicular to the axial direction of the shell body 1 is between 0.97 and 1. Within this range, the value of "S2 / S3" will not be too large or too small, allowing the protrusion 202 to be easily inserted into the shell body 1, ensuring efficient installation of the cover plate 2 and reducing assembly difficulty. Simultaneously, after the cover plate 2 is placed over the opening end 101 of the shell body 1, the gap between the outer wall of the protrusion 202 and the inner wall of the shell body 1 will not be too large, preventing severe misalignment of the cover plate 2. This ensures that the welding area of ​​the body portion 201 facing the shell body 1 and the end face of the opening end 101 is uniform and consistent, meeting the requirements for welding area size, thereby guaranteeing the welding strength and yield.

[0101] For example, the ratio of "S2 / S3" can be 0.97, 0.975, 0.983, 0.994, 1, etc.

[0102] In other embodiments, the protrusion 203 is a continuous protrusion arranged circumferentially along the protrusion 202, and the ratio between the outer circumferential surface area S2 of the protrusion 202 perpendicular to the axial direction of the cover plate 2 and the inner circumferential surface area S3 of the shell body 1 perpendicular to the axial direction of the shell body 1 is in the range of 0.95-0.97. In this embodiment, the protrusion 203 is an annular structure arranged circumferentially around the protrusion 202. Compared with discontinuous protrusions, this continuous protrusion will affect the shell insertion efficiency of the cover plate 2 to a certain extent, making it more difficult to align the protrusion 202 with the shell body 1. However, this continuous protrusion is easier to form, which can improve processing efficiency and reduce processing costs.

[0103] At this time, in order to facilitate the installation of the continuous protrusion 203 into the shell, the ratio between the outer peripheral surface area S2 of the protrusion 202 perpendicular to the axial direction of the cover plate 2 and the inner peripheral surface area S3 of the shell body 1 perpendicular to the axial direction of the shell body 1 is limited, that is, the ratio between the outer peripheral surface area S2 of the protrusion 202 perpendicular to the axial direction of the cover plate 2 and the inner peripheral surface area S3 of the shell body 1 perpendicular to the axial direction of the shell body 1 is in the range of 0.95-0.97. There is a certain gap between the outer wall of the protrusion 202 and the inner wall of the shell body 1 to facilitate installation into the shell. Within the aforementioned ratio range, the value of "S2 / S3" will not be too large or too small. The protrusion 202 can be easily inserted into the shell body 1, ensuring the efficiency of the cover plate 2 entering the shell, reducing the assembly difficulty, and preventing serious deformation of the shell body. At the same time, after the cover plate 2 is placed on the opening end 101 of the shell body 1, the gap between the outer wall of the protrusion 202 and the inner wall of the shell body 1 will not be too large, and the cover plate 2 will not have serious misalignment. This ensures that the welding area of ​​the body part 201 facing the shell body 1 and the end face of the opening end 101 is uniform and consistent, and the size of the welding area meets the requirements, thereby ensuring the welding strength and welding yield of both.

[0104] For example, the ratio of "S2 / S3" can be 0.95, 0.955, 0.96, 0.962, 0.97, etc.

[0105] Furthermore, the number of protrusions 203 is even, and the even number of protrusions 203 are arranged symmetrically in pairs radially relative to the protrusion 202.

[0106] To make the overall structure of the protrusion 202 more symmetrical and to allow for quick alignment between the protrusion 202 and the shell body 1, the number of protrusions 203 is an even number, such as 2, 4, 6, or 8. Furthermore, the even number of protrusions 203 are arranged symmetrically in pairs radially relative to the protrusion 202. Figure 9 As shown, in this embodiment, there are 8 protrusions 203, and the 8 protrusions 203 are arranged symmetrically in pairs with respect to the radial direction of the protrusion 202.

[0107] Furthermore, in the axial direction of the cover plate 2, the protrusion 203 is located below the middle of the protrusion 202; the ratio between the outer peripheral surface area S2 of the protrusion 202 perpendicular to the axial direction of the cover plate 2 and the inner peripheral surface area S3 of the shell body 1 perpendicular to the axial direction of the shell body 1 is in the range of 0.95-0.98.

[0108] In the axial direction of cover plate 2 ( Figure 1 In the y-direction, the position where the height of the protrusion 202 is centered is the middle of the protrusion 202. The dimensions above the middle of the protrusion 202 are the same as the dimensions below the middle. The position above the middle of the protrusion 202 is the upper part of the protrusion 202, and the position below the middle of the protrusion 202 is the lower part of the protrusion 202. For example... Figure 7 As shown, position a is the middle position of the protrusion 202, position b is the position above the middle of the protrusion 202, and position c is the position below the middle of the protrusion 202.

[0109] The protrusion 203 is located below the middle of the protrusion 202, that is, the protrusion 203 is located at the lower part of the protrusion 202. During the process of inserting the protrusion 202 into the shell body 1, the protrusion 203 can quickly position itself with the shell body 1, so that the insertion position of the protrusion 202 is accurate and the efficiency of the cover plate 2 entering the shell is improved.

[0110] At this time, in order to facilitate the installation of the protrusion 203 into the shell, the ratio between the outer peripheral surface area S2 of the protrusion 202 perpendicular to the axial direction of the cover plate 2 and the inner peripheral surface area S3 of the shell body 1 perpendicular to the axial direction of the shell body 1 is limited, that is, the ratio between the outer peripheral surface area S2 of the protrusion 202 perpendicular to the axial direction of the cover plate 2 and the inner peripheral surface area S3 of the shell body 1 perpendicular to the axial direction of the shell body 1 is in the range of 0.95-0.98. Within the aforementioned ratio range, the value of "S2 / S3" will not be too large or too small. The protrusion 202 can be easily inserted into the shell body 1, ensuring the efficiency of the cover plate 2 entering the shell, reducing the assembly difficulty, and preventing serious deformation of the shell body. At the same time, after the cover plate 2 is placed on the opening end 101 of the shell body 1, the gap between the outer wall of the protrusion 202 and the inner wall of the shell body 1 will not be too large, and the cover plate 2 will not have serious misalignment. This ensures that the welding area of ​​the body part 201 facing the shell body 1 and the end face of the opening end 101 is uniform and consistent, and the size of the welding area meets the requirements, thereby ensuring the welding strength and welding yield of both.

[0111] For example, the ratio of "S2 / S3" can be 0.95, 0.955, 0.96, 0.972, 0.98, etc.

[0112] In other embodiments, depending on different configuration requirements, a protrusion 203 is disposed at the middle of the protrusion 202 along its axial direction. The ratio between the outer circumferential surface area S2 of the protrusion 202 perpendicular to the axial direction of the cover plate 2 and the inner circumferential surface area S3 of the shell body 1 perpendicular to the axial direction of the shell body 1 is in the range of 0.98-1. During the insertion of the protrusion 202 into the shell body 1, the lower part of the protrusion 202 quickly enters the shell, and then is positioned with the shell body 1 by the protrusion 203. This facilitates the rapid insertion and engagement of the protrusion 202 and the shell body 1, and also improves the efficiency of the cover plate 2 entering the shell.

[0113] At this point, the protrusion 202 is relatively easy to install into the shell. The ratio between the outer circumferential surface area S2 of the protrusion 202 perpendicular to the axial direction of the cover plate 2 and the inner circumferential surface area S3 of the shell body 1 perpendicular to the axial direction of the shell body 1 can be in the range of 0.98-1. Within the above ratio range, the value of "S2 / S3" will not be too large or too small, and the protrusion 202 can be easily inserted into the shell body 1, ensuring the efficiency of the cover plate 2's installation into the shell and reducing the assembly difficulty. At the same time, after the cover plate 2 is placed on the opening end 101 of the shell body 1, the gap between the outer wall of the protrusion 202 and the inner wall of the shell body 1 will not be too large, and the cover plate 2 will not have serious misalignment problems. This ensures that the welding area of ​​the body part 201 facing the shell body 1 and the end face of the opening end 101 is uniform and consistent, and the size of the welding area meets the requirements, thereby ensuring the welding strength and welding yield of both.

[0114] For example, the ratio of "S2 / S3" can be 0.98, 0.99, 0.996, 1, etc.

[0115] In this embodiment, protrusions 203 are disposed at the upper, middle, and lower parts of the protrusion 202, such as... Figure 6 As shown, this protrusion 203 structure is relatively simple, easy to manufacture and form, and helps to reduce manufacturing costs.

[0116] Furthermore, the outer wall of protrusion 203 is an arc-shaped surface.

[0117] The outer wall of the protrusion 203 abuts against the inner wall of the shell body 1. The inner wall of the shell body 1 has an arc-shaped structure. In order to improve the fit between the outer wall of the protrusion 203 and the inner wall of the shell body 1, the outer wall of the protrusion 203 is an arc-shaped surface.

[0118] Optionally, the outer wall of the protrusion 203 has the same curvature as the inner wall of the shell body 1, so that the outer wall of the protrusion 203 fits the inner wall of the shell body 1 better, improving the contact and positioning effect between the protrusion 203 and the shell body 1, while facilitating the insertion of the protrusion 203 into the shell and improving the insertion efficiency of the cover plate 2 into the shell.

[0119] Furthermore, along the radial direction of the protrusion 202, the thickness t of the protrusion 203 ranges from 0.5 mm to 4 mm.

[0120] The protrusion 203 protrudes from the outer wall of the protrusion 202. Along the radial direction of the protrusion 202, the dimension of the protrusion 203 protruding from the protrusion 202 is equal to the thickness of the protrusion 203. Figure 6 As shown, the thickness of protrusion 203 is t.

[0121] If the thickness t of the protrusion 203 is too large, the protrusion 203 will easily expand the shell body 1 after the protrusion 202 is inserted into the shell body 1, causing severe deformation of the shell body 1 and affecting the quality of the battery product. If the thickness t of the protrusion 203 is too small, the protrusion 203 will not be able to abut against the inner wall of the shell body 1, and the protrusion 202 cannot be ensured to be centered, that is, the cover plate 2 cannot be centered relative to the shell body 1.

[0122] In this embodiment, the thickness t of the protrusion 203 ranges from 0.5mm to 4mm. Within the above range, the thickness t of the protrusion 203 is neither too large nor too small, which enables the protrusion 203 to abut and position against the shell body 1, so that the protrusion 202 is centered and the cover plate 2 is centered relative to the shell body 1, and it will not cause the shell body 1 to deform, thus ensuring the quality of the battery product.

[0123] For example, the thickness t of the protrusion 203 can be 0.5mm, 0.7mm, 1.2mm, 2.8mm, 3.5mm, 4mm, etc.

[0124] Furthermore, along the axial direction of the protrusion 202, the height h of the protrusion 203 ranges from 0.2mm to 1.5mm.

[0125] The protrusion 203 protrudes from the outer wall of the protrusion 202, and along the axial direction of the protrusion 202, the protrusion 203 has a certain height, such as... Figure 6 As shown, the height of protrusion 203 is h.

[0126] If the height h of the protrusion 203 is too high, it will be difficult for the protrusion 202 to be inserted into the shell body 1, affecting the efficiency of the cover plate 2 entering the shell. If the height h of the protrusion 203 is too low, the effect of the protrusion 203 abutting and positioning with the inner wall of the shell body 1 will be average.

[0127] In this embodiment, the height h of the protrusion 203 is in the range of 0.2mm-1.5mm. Within the above range, the height h of the protrusion 203 is neither too high nor too low, which enables the protrusion 203 to abut and be positioned against the shell body 1, so that the protrusion 202 and the cover plate 2 are centered, and the efficiency of the cover plate 2 entering the shell is guaranteed.

[0128] Furthermore, the diameter of the outer circumferential surface where the outer wall of protrusion 203 is located is d1, and the diameter of the inner circumferential surface where the inner wall of shell body 1 is located is d2. The ratio of d1 / d2 is in the range of 1-1.05.

[0129] like Figure 2 , Figure 9 As shown, in order to fit with the inner wall of the shell body 1, the outer wall of the protrusion 203 is an arc-shaped surface. In the direction perpendicular to the axial direction of the cover plate 2, the outer wall of the protrusion 203 is an arc segment of a circular surface, the diameter of which is d1, that is, the diameter d1 of the outer circumferential surface where the outer wall of the protrusion 203 is located. In the direction perpendicular to the axial direction of the shell body 1, the inner wall of the shell body 1 forms a circular surface, the diameter of which is d2, that is, the diameter d2 of the inner circumferential surface where the inner wall of the shell body 1 is located.

[0130] In this embodiment, the ratio of d1 / d2 is in the range of 1-1.05. Within the above ratio range, the diameter d1 and the diameter d2 are relatively close, so that the protrusion 203 is in an interference fit with the inner wall of the shell body 1, thereby ensuring that the outer wall of the protrusion 203 abuts against the inner wall of the shell body 1 and improving the fit between the cover plate 2 and the shell body 1.

[0131] For example, the ratio of d1 / d2 can be 1, 1.01, 1.02, 1.03, 1.04, or 1.05.

[0132] Furthermore, the outer circumferential diameter d3 of the main body 201 ranges from 40mm to 50mm, and the number of protrusions 203 ranges from 2 to 16.

[0133] like Figure 9 As shown, a circular surface is formed on the outer wall of the body portion 201 of the cover plate 2 in a direction perpendicular to the axial direction of the cover plate 2. The diameter of this circular surface is d3, which is the outer circumference diameter d3 of the body portion 201. In this embodiment, the value of the diameter d3 is in the range of 40mm-50mm. For example, the diameter d3 can be 40mm, 42mm, 45mm, 48mm, or 50mm.

[0134] Under this premise, the number of protrusions 203 can be set to 2-16, for example: the number of protrusions 203 can be set to 2, 3, 6, 8, 11, 14, or 16.

[0135] The number of protrusions 203 should not be too many, otherwise it will be difficult to align the protrusions 202 with the shell body 1. Moreover, when the protrusions 202 are inserted into the shell body 1, too many protrusions 203 can easily stretch the shell body 1, causing the shell body 1 to deform and affecting the battery quality.

[0136] Optionally, the number of protrusions 203 is an even number, i.e., 2n, where n can be 1, 2, 3, 4, 5, 6, 7, or 8. In this embodiment, n is 4, and the number of protrusions 203 is 8.

[0137] Furthermore, the larger the diameter d3 of the main body 201, the more protrusions 203 should be provided. This is because the larger the diameter d3 of the main body 201, the more difficult it is to position the cover plate 2 and the shell body 1 when they are assembled, and more protrusions 203 are needed to facilitate the positioning of the protrusions 202 and the shell body 1.

[0138] This embodiment also provides a cylindrical battery, which includes the casing as described above. In this cylindrical battery, the protrusion 202 of the cover plate 2 is easily inserted into the casing body 1, which facilitates the installation of the cover plate 2, reduces assembly difficulty, and improves the installation efficiency of the cover plate 2. Moreover, after the cover plate 2 is installed into the casing body 1, the offset of the cover plate 2 relative to the casing body 1 is small, and the cover plate 2 can be more centrally positioned. The contact area between the body portion 201 of the cover plate 2 and the end face of the opening end 101 of the casing body 1 is large and the contact area distribution is more uniform, which can ensure the welding strength and welding yield between the cover plate 2 and the casing body 1, thereby improving the overall product quality of the cylindrical battery.

[0139] Of course, this cylindrical battery also includes other structures that are present in existing cylindrical batteries, which will not be elaborated here.

[0140] The assembly process of the cylindrical battery cover 2 and the housing body 1 in this embodiment will be described below with reference to the accompanying drawings:

[0141] First, align the protrusion 202 of the cover plate 2 with the opening end 101 of the shell body 1, and insert the protrusion 202 into the shell body 1. Since the protrusion 203 is located near the lower part of the protrusion 202, the protrusion 203 enters the shell body 1 first to achieve the positioning of the protrusion 202. The outer wall of the protrusion 203 presses against the inner wall of the shell body 1.

[0142] Continue inserting the protrusion 202 into the shell body 1 until the side of the body part 201 facing the shell body 1 contacts the end face of the opening end 101. At this time, the protrusion 202 is relatively centered relative to the shell body 1, that is, the cover plate 2 is centered relative to the shell body 1.

[0143] Next, the side of the main body 201 facing the shell body 1 is welded to the end face of the opening end 101, thus completing the assembly of the cover plate 2 and the shell body 1.

[0144] The following tests were conducted on the welding strength between the cylindrical battery cover and the casing body, as well as the ease with which the cover was installed into the casing:

[0145] Table 1

[0146]

[0147]

[0148] The test data in the table above shows that:

[0149] For embodiments 1 to 12, the outer peripheral surface area S2 of the protrusion 202 perpendicular to the axial direction of the cover plate 2, and the inner peripheral surface area S3 of the shell body 1 perpendicular to the axial direction of the shell body 1, satisfy S2≤S3, and the ratio of S2 / S3 is in the range of 0.95-1, and the value of "S1 / (S2 / S3)" is 1250mm. 2 ≤S1 / (S2 / S3)≤2000mm 2 Within the specified range, cover plate 2 can be smoothly inserted into the casing. The installation difficulty of cover plate 2 is relatively small, the insertion rate of cover plate 2 is high, and after cover plate 2 is installed, the welding strength between cover plate 2 and casing body 1 meets the requirements. Cylindrical batteries using this type of casing have high product quality.

[0150] For Comparative Examples 1 and 2, the outer peripheral surface area S2 of the protrusion 202 perpendicular to the axial direction of the cover plate 2, and the inner peripheral surface area S3 of the shell body 1 perpendicular to the axial direction of the shell body 1, satisfy S2≤S3, and the ratio of S2 / S3 is within the range of 0.95-1. However, the value of "S1 / (S2 / S3)" exceeds 1250mm. 2 ≤S1 / (S2 / S3)≤2000mm 2 The range. At this time, although the cover plate 2 can be installed in the shell in Comparative Example 1, the welding strength between the cover plate 2 and the shell body 1 does not meet the requirements. Although the welding strength between the cover plate 2 and the shell body 1 in Comparative Example 2 is acceptable, the cover plate 2 cannot be installed in the shell. Cylindrical batteries using this type of shell have low yield and poor product quality.

[0151] 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 housing, characterized in that, For cylindrical batteries, the housing includes: The shell body (1) has at least one open end (101). A cover plate (2) is provided on the opening end (101). The cover plate (2) includes a body part (201) and a protrusion (202). The protrusion (202) is provided on the side of the body part (201) facing the shell body (1). The protrusion (202) is at least partially placed inside the shell body (1). The side of the body part (201) facing the shell body (1) is connected to the end face of the opening end (101). The outer peripheral surface area of ​​the main body (201) perpendicular to the axial direction of the cover plate (2) is S1, the outer peripheral surface area of ​​the protrusion (202) perpendicular to the axial direction of the cover plate (2) is S2, and the inner peripheral surface area of ​​the shell body (1) perpendicular to the axial direction of the shell body (1) is S3. S2≤S3, satisfying: 1250mm 2 ≤S1 / (S2 / S3)≤2000mm 2 The ratio of S2 / S3 ranges from 0.95 to 1.

2. The housing according to claim 1, characterized in that, Along the radial direction of the cover plate (2), the distance from one side of the outer wall of the protrusion (202) to the inner wall of the shell body (1) is L1, and the distance from the other side of the outer wall of the protrusion (202) to the inner wall of the shell body (1) is L2, satisfying: 0.6≤L1 / L2≤1.

4.

3. The housing according to claim 1, characterized in that, Along the radial direction of the cover plate (2), the distance from one side of the outer wall of the protrusion (202) to the inner wall of the shell body (1) is L1, and the distance from the other side of the outer wall of the protrusion (202) to the inner wall of the shell body (1) is L2, and L1=L2, satisfying: 1700mm 2 ≤S1 / (S2 / S3)≤2000mm 2 .

4. The housing according to claim 1, characterized in that, Along the radial direction of the cover plate (2), the distance from one side of the outer wall of the protrusion (202) to the inner wall of the shell body (1) is L1, and the distance from the other side of the outer wall of the protrusion (202) to the inner wall of the shell body (1) is L2, and L1 > L2 or L1 < L2, satisfying: 1250mm 2 ≤S1 / (S2 / S3)≤1650 mm 2 .

5. The housing according to claim 1, characterized in that, Along the radial direction of the cover plate (2), the distance from one side outer wall of the protrusion (202) to the inner wall of the shell body (1) is L1, and the distance from the other side outer wall of the protrusion (202) to the inner wall of the shell body (1) is L2. The value range of L1 is 0.02mm-0.5mm, and the value range of L2 is 0.02mm-0.5mm.

6. The housing according to claim 1, characterized in that, Along the axial direction of the cover plate (2), the height of the protrusion (202) inside the shell body (1) is H, and the value of H ranges from 0.2mm to 2mm.

7. The housing according to claim 1, characterized in that, The range of the outer peripheral surface area S1 of the main body (201) perpendicular to the axial direction of the cover plate (2) is 1200mm²-2000mm². The area S2 of the outer peripheral surface of the protrusion (202) perpendicular to the axial direction of the cover plate (2) ranges from 1100mm² to 2000mm². The value range of the inner circumferential surface area S3 of the shell body (1) perpendicular to the axial direction of the shell body (1) is 1200mm²-2000mm².

8. The housing according to any one of claims 1-7, characterized in that, The outer wall of the protrusion (202) is provided with a protrusion (203), the protrusion (203) is arranged in the radial direction, and at least part of the outer wall of the protrusion (203) abuts against the inner wall of the shell body (1), satisfying: 1500mm 2 ≤S1 / (S2 / S3)≤2000 mm 2 .

9. The housing according to claim 8, characterized in that, The protrusion (203) is a continuous protrusion arranged circumferentially along the protrusion (202). The ratio between the outer circumferential surface area S2 of the protrusion (202) perpendicular to the axial direction of the cover plate (2) and the inner circumferential surface area S3 of the shell body (1) perpendicular to the axial direction of the shell body (1) is in the range of 0.95-0.

97.

10. The housing according to claim 8, characterized in that, Along the circumference of the protrusion (202), at least two protrusions (203) are provided, and at least two protrusions (203) are spaced apart. The ratio between the outer circumferential surface area S2 of the protrusion (202) perpendicular to the axial direction of the cover plate (2) and the inner circumferential surface area S3 of the shell body (1) perpendicular to the axial direction of the shell body (1) is in the range of 0.97-1.

11. The housing according to claim 10, characterized in that, The spacing between adjacent protrusions (203) is the same in the circumferential direction.

12. The housing according to claim 10, characterized in that, The number of protrusions (203) is an even number, and the even number of protrusions (203) are arranged symmetrically in pairs in the radial direction relative to the protrusion (202).

13. The housing according to claim 8, characterized in that, On the axial direction of the cover plate (2), the protrusion (203) is located below the middle of the protrusion (202); the ratio between the outer peripheral surface area S2 of the protrusion (202) perpendicular to the axial direction of the cover plate (2) and the inner peripheral surface area S3 of the shell body (1) perpendicular to the axial direction of the shell body (1) is in the range of 0.95-0.

98.

14. The housing according to claim 8, characterized in that, In the axial direction of the protrusion (202), the protrusion (203) is disposed in the middle of the protrusion (202); the ratio between the outer peripheral surface area S2 of the protrusion (202) perpendicular to the axial direction of the cover plate (2) and the inner peripheral surface area S3 of the shell body (1) perpendicular to the axial direction of the shell body (1) is in the range of 0.98-1.

15. The housing according to claim 8, characterized in that, The outer wall of the protrusion (203) is an arc-shaped surface.

16. The housing according to claim 8, characterized in that, Along the radial direction of the protrusion (202), the thickness t of the protrusion (203) ranges from 0.5mm to 4mm; along the axial direction of the protrusion (202), the height h of the protrusion (203) ranges from 0.2mm to 1.5mm.

17. The housing according to claim 8, characterized in that, The diameter of the outer circumferential surface of the outer wall of the protrusion (203) is d1, and the diameter of the inner circumferential surface of the inner wall of the shell body (1) is d2. The ratio of d1 / d2 is in the range of 1-1.

05.

18. The housing according to claim 8, characterized in that, The outer diameter d3 of the main body (201) ranges from 40mm to 50mm, and the number of protrusions (203) is 2 to 16.

19. A cylindrical battery, characterized in that, Includes the housing as described in any one of claims 1-18.

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