Housing and cylindrical battery

Abstract

Housing characterized in that it comprises the following: a housing body (1) wherein at least one end is an open end (101); a cover plate (2) covering the open end (101), wherein the cover plate (2) comprises a main section (201) and a projecting section (202), wherein the projecting section (202) is located on the side of the main section (201) facing the housing body (1), the projecting section (202) is at least partially located within the housing body (1), and the main section (201) is connected to the end face of the open end (101) on the side facing the housing body (1); wherein in the radial direction of the cover plate (2) the distance from one outer wall of the projection section (202) to the inner wall of the housing body (1) is L1 and the distance from the other outer wall of the projection section (202) to the inner wall of the housing body (1) is L2, wherein L1 is in the range of 0.02 mm to 0.5 mm and L2 is in the range of 0.02 mm to 0.5 mm.

Description

Technical area

[0001] The present application relates to the technical field of batteries for electric vehicles and in particular to a housing and a cylindrical battery. Background technology

[0002] Cylindrical batteries are characterized by their cylindrical shape. The outer casing is typically made of metal (such as steel or aluminum), and inside are a positive terminal, a negative terminal, and a separator, which are wound together and then sealed and shaped. The standardized design of cylindrical batteries allows for high manufacturing efficiency and adaptability, making them one of the most common packaging formats for electric vehicle batteries.

[0003] The outer casing of a cylindrical battery essentially comprises a housing and a cover plate, with the cover plate welded to the open end of the housing to seal it. However, after the cover plate and housing are assembled, the cover plate tends to shift laterally relative to the housing, resulting in significant misalignment. This misalignment compromises the weld strength and weld yield at the open end between the cover plate and housing, and consequently, the product quality of the cylindrical battery. Content of the utility model

[0004] Against this background, the present application provides a cylindrical battery with a housing to solve the problem that the cover plate of existing cylindrical batteries tends to warp to one side after being installed in the housing, which impairs the weld strength between the cover plate and the housing as well as the battery quality.

[0005] In a first aspect, the present application provides a housing that includes the following: a housing body, wherein at least one end is an open end; a cover plate covering the open end, the cover plate comprising a main section and a projection section, the projection section being located on the side of the main section facing the housing body, the projection section being at least partially inside the housing body, and the main section being connected to the end face of the open end on the side facing the housing body; wherein, in the radial direction of the cover plate, the distance from one outer wall of the projection section to the inner wall of the housing body is L1 and the distance from the other outer wall of the projection section to the inner wall of the housing body is L2, wherein L1 is in the range of 0.02 mm to 0.5 mm and L2 is in the range of 0.02 mm to 0.5 mm.

[0006] Advantageous effects: The housing according to the present application comprises a housing body and a cover plate, wherein the cover plate is arranged at the open end of the housing body and the cover plate comprises a main section and a projecting section, wherein, in the radial direction of the cover plate, the distance from one outer wall of the projecting section to the inner wall of the housing body is L1, and the distance from the other outer wall of the projecting section to the inner wall of the housing body is L2. L1 and L2 are in the range of 0.02 mm to 0.5 mm. Within this range, the projecting section of the cover plate can be more easily inserted into the housing body, which facilitates the insertion of the cover plate into the housing and reduces assembly difficulty, thereby improving the efficiency of inserting the cover plate.

[0007] Furthermore, after insertion into the housing body, the offset of the cover plate to the housing body is small, which allows the cover plate to be positioned more centrally and the contact area between the main section of the cover plate and the end face of the open end on the housing body is larger and more evenly distributed, which ensures the weld strength and weld yield between the cover plate and the housing body and thus improves the overall quality of the cylindrical battery.

[0008] In a second aspect, the present application provides a cylindrical battery comprising a housing according to the first aspect.

[0009] Since the cylindrical battery of this aspect encompasses the housing according to the first aspect, it has the same advantageous effects as the housing described above, which are not repeated here. Figures

[0010] To illustrate the technical solutions in the specific embodiments or the prior art of the present application more clearly, the accompanying drawings, which must be used in describing the specific embodiments or the prior art, are briefly presented below. It is evident that the accompanying drawings represent some of the embodiments of the present application in the following description, and that other drawings can be obtained by general technical personnel in this field, provided they are not performing any creative work, based on the accompanying drawings. Fig. Figure 1 is a schematic overall representation of the cylindrical battery of the present application; Fig. 2 is an exploded view of the cylindrical battery of the present application (only the casing and cover plate are preserved); Fig. Figure 3 is a cross-sectional view of the cylindrical battery of the present application; Fig. Figure 4 is an enlarged schematic representation of part A in Fig. 3; Fig. Figure 5 is a side view of the cover plate of the cylindrical battery of the present application; Fig. Figure 6 is an enlarged schematic representation of Part B in Fig. 5; Fig. Figure 7 is a schematic representation of different positions of the projection section in the present application; Fig. Figure 8 is a perspective schematic representation of the cover plate in the cylindrical battery of the present application; Fig. Figure 9 is a bottom view of the cover plate in the cylindrical battery of the present application; Fig.Figure 10 is a scaled schematic representation of the housing body and the cover plate in the cylindrical battery of the present application. Reference symbols in the figures: 1. Housing body; 101. Open end; 2. Cover plate; 201. Main section; 202. Projection section; 203. Projection. Specific embodiments

[0011] To clarify the purpose, technical solutions, and advantages of the embodiments in this application, the technical solutions of the embodiments in this application are described clearly and completely below with reference to the figures of the embodiments in this application. The described embodiments naturally represent only a part of the present application and do not constitute the entirety of all embodiments. Based on the embodiments in this application, all other embodiments that a person skilled in the art in this field obtains without creative effort fall within the scope of protection of this application.

[0012] The cylindrical batteries currently available on the market essentially comprise a casing and a cover plate, wherein at least one end of the casing is open, the cover plate is designed to cover the open end, and the side of the cover plate facing the casing is welded to the end face of the open end to seal the casing of the cylindrical battery. The cover plate has a projection on the side facing the casing. During installation, this projection is inserted into the casing. A gap is created between the outer circumferential wall of the projection and the inner circumferential wall of the casing, which facilitates 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 shifted to one side (e.g., to the left). In this case, the performance on the other side (e.g.,(to the right) the contact surface (welding surface) between the side of the cover plate facing the housing and the end face of the open end. During welding, the weld strength between the cover plate and the housing is insufficient, which impairs the weld yield and thus the overall quality of the cylindrical battery.

[0013] Based on this, the present application presents a cylindrical battery with high weld strength between the cover plate and the casing, good yield and guaranteed product quality.

[0014] With reference to the Fig. In sections 1 to 10, an embodiment of the housing and cylindrical battery of the present application is described below.

[0015] According to the embodiment of the present application, in one aspect a housing for a cylindrical battery is provided, and the housing comprises 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 comprises a main section 201 and a projecting section 202, wherein the projecting section 202 is located on the side of the main section 201 facing the housing body 1, the projecting section 202 is at least partially located within the housing body 1 and the main section 201 is connected to the end face of the open end 101 on the side facing the housing body 1;The area of ​​the outer circumferential surface of the main section 201 is S1 perpendicular to the axial direction of the cover plate 2, the area of ​​the outer circumferential surface of the projection section 202 perpendicular to the axial direction of the cover plate 2 is S2, the area of ​​the inner circumferential surface of the housing body 1 perpendicular to the axial direction of the housing body 1 is S3, where S2 ≤ S3 and the following condition is met: 1250 mm; 2 ≤ S1 / (S2 / S3) ≤ 2000 mm 2 .

[0016] By checking the value range of “S1 / (S2 / S3)”, i.e. 1250 mm 2 ≤S1 / (S2 / S3) ≤ 2000 mm 2This housing allows for easy insertion of the protruding section 202 of the cover plate 2 into the housing body 1, which facilitates the insertion of the cover plate 2 into the housing and reduces the assembly difficulty (insertion difficulty), thereby improving the efficiency of inserting the cover plate 2. Furthermore, after the cover plate 2 is inserted into the housing body 1, the offset of the cover plate 2 relative to the housing body is small, allowing the cover plate 2 to be positioned more centrally. This results in a larger and more evenly distributed contact area between the main section 201 of the cover plate 2 and the end face of the open end 101 on the housing body 1. This ensures weld strength and weld yield between the cover plate 2 and the housing body 1, thus improving the overall quality of the cylindrical battery.

[0017] It should be noted that the weld strength is assessed based on the effective penetration depth (0.35 mm) and effective penetration width (0.6 mm) after welding the cover plate and the housing body. If these values ​​exceed the standard values, the weld strength meets the requirements; if they are below, the weld strength is insufficient. The ease of insertion into the housing is determined by whether the cover plate can be inserted into the housing body under an insertion pressure of 100 N. If the cover plate can be inserted into the housing body, the insertion process is straightforward; if it cannot, the insertion process is difficult.

[0018] As in the Fig. As shown in Figures 1 and 2, the cylindrical battery has a cylindrical shape. Fig.1 corresponds to the x-direction of the radial direction of the cylindrical battery (radial direction of the casing), and the y-direction corresponds to the axial direction of the cylindrical battery (axial direction of the casing).

[0019] The housing consists of a housing body 1 and a cover plate 2. After assembly, the housing body 1 and the cover plate 2 form the housing of a cylindrical battery. The housing body 1 is cylindrical. Along the axial direction of the cylindrical battery, the housing body 1 has two ends. As shown in Fig.As shown in Figure 1, the housing body 1 has an upper end and a lower end. At least one end of the housing body 1 is an open end 101, meaning that either both the upper and lower ends of the housing body 1 are open ends 101, or only the upper end of the housing body 1 is an open end 101, or only the lower end of the housing body 1 is an open end 101. In this embodiment, the upper end of the housing body 1 is an open end 101. The cover plate 2 interacts with the housing body 1 and is designed to cover the open end 101 in order to close the housing and ensure the functionality of the cylindrical battery.

[0020] The housing body 1 can be made of aluminum or an aluminum alloy, such as an aluminum-manganese alloy, an aluminum-magnesium alloy, etc., or of steel, such as stainless steel, carbon steel, nickel-plated steel, titanium, etc. The material of the cover plate 2 can be the same as that of the housing body 1.

[0021] The side wall of the housing body 1 has a certain thickness, the outer wall of the housing body 1 forms the outer cylindrical surface of the cylindrical battery housing, and the inner wall of the housing body 1 encloses the circumferential space, thus forming a receiving space in which the winding cell of the cylindrical batteries and other structural components are located.

[0022] A wound cell, also called a battery cell, is a battery cell body formed by winding together a cathode plate, an anode plate and an intermediate separator.

[0023] The cathode sheet comprises a cathode current collector and a cathode active material. The cathode current collector can be made of metals such as aluminum foil, nickel foil, or stainless steel, or it can be a composite foil of metals and insulating materials. The cathode active material comprises the main cathode active material, conductive materials, binders, etc., wherein the main cathode active material includes one or more of the lithium-containing positive electrode active materials such as lithium iron phosphate, ternary materials containing nickel, cobalt, and manganese, and lithium manganese iron phosphate.

[0024] The anode plate comprises an anode current collector and an anode active material. The anode current collector can be made of metals such as copper foil, aluminum foil, or stainless steel, or it can be a composite foil material of metals and insulating materials. The anode active material comprises the main anode active material, conductive materials, binders, etc., wherein the main anode active material comprises one or more of the following materials: synthetic graphite, natural graphite, silicon carbide, silicon dioxide, lithium titanate, etc.

[0025] In this embodiment, the radial direction of the housing body 1 is equal to the radial direction of the cylindrical battery (x-direction in Fig. 1), and the axial direction of the housing body 1 is equal to the axial direction of the cylindrical battery (y-direction in Fig. 1).

[0026] As in the Fig.As shown in Figures 5 to 9, the cover plate 2 consists of a main section 201 and a projecting section 202. The main section 201 is located further away from the housing body 1 compared to the projecting section 202. Considering, for example, the perspective of Fig. 1 and Fig.In this embodiment, the main section 201 is located in the upper region of the cover plate 2 and the projecting section 202 in the lower region of the cover plate 2, in the axial direction of the cylindrical battery. The projecting section 202 is arranged on a side of the main section 201 facing the housing body 1, and the projecting section 202 protrudes from a side of the main section 201 facing the housing body 1. In this embodiment, the projecting section 202 is a projection. To facilitate the fit between the cover plate 2 and the housing body 1, and also to simplify the shaping of the cover plate 2, both the main section 201 and the projecting section 202 are understandably cylindrical structures with a relatively small axial height. Optionally, the axial position of the cover plate 2 corresponds to the axial position of the main section 201 and the projecting section 202.The radial direction of the cover plate 2 corresponds to the radial direction of the cylindrical battery (x-direction in . Fig. 1), and the axial direction of the cover plate 2 corresponds to the axial direction of the cylindrical battery (y-direction in Fig. 1).

[0027] Both the main section 201 and the projecting section 202 are cylindrical structures, and the cross-sections of the main section 201 and the projecting section 202 perpendicular to the axial direction are circular. To facilitate the insertion of the projecting section 202 into the housing body 1 and the connection between the main section 201 and the end face of the open end 101, the radius of the circular area of ​​the projecting section 202 perpendicular to the axial direction is smaller than the radius of the circular area of ​​the main section 201 perpendicular to the axial direction. Furthermore, the radius of the circular area of ​​the projecting section 202 perpendicular to the axial direction is smaller than the radius of the inner wall of the housing body 1, while the radius of the circular area of ​​the main section 201 perpendicular to the axial direction is larger than the radius of the inner wall of the housing body 1.

[0028] As in the Fig.As shown in Figures 3 to 4, when the cover plate 2 is placed on the open end 101 of the housing body 1, the projecting section 202 is at least partially inserted into the housing body 1. The main section 201 facing the housing body 1 contacts the end face of the open end 101 and then connects to the end face of the open end 101 to seal the housing of the cylindrical battery. In this embodiment, the connection between the main section 201 and the end face of the open end 101 on the side facing the housing body 1 is made by welding. If the main section 201 is not welded to the end face of the open end 101 on the side facing the housing body 1, all projecting sections 202 are located within the housing body 1.After the main section 201 has been welded to the end face of the open end 101 on the side facing the housing body 1, some of the projecting sections 202 are located outside the housing body 1 due to the weld thickness, but at this point most of the projecting sections 202 are still inside the housing body 1. After the cover plate 2 has been placed on the open end 101 of the housing body 1, a certain gap is created between the outer wall of the projecting section 202 and the inner wall of the housing body 1, so that the projecting section 202 of the cover plate 2 can be easily inserted into the housing body 1 and thus the housing assembly of the cover plate 2 is achieved.

[0029] When the cover plate 2 is placed on the open end 101 of the housing body 1, the edge of the main section 201 facing the housing body 1 overlaps the end face of the open end 101 between the inner wall and the outer wall of the housing body 1. In plan view, the inner wall of the housing body 1 is located inside the outer wall of the main section 201, while the outer wall of the housing body 1 is flush with the outer wall of the main section 201, and both lie on the same arc surface.

[0030] As in Fig. Figure 10 shows the area of ​​the outer circumferential surface of the main section 201 perpendicular to the axial direction of the cover plate 2 S1, the area of ​​the outer circumferential surface of the projection section 202 perpendicular to the axial direction of the cover plate 2 S2 and the area of ​​the inner circumferential surface of the housing body 1 perpendicular to the axial direction of the housing body 1 S3.

[0031] In particular, the cross-section of the main section 201 perpendicular to the axial direction of the cover plate 2 is a circular area. The outer edge of the main section 201 (the outer edge of the main section 201 extends along the axial direction of the cover plate 2 and forms the outer wall of the main section 201) forms this circular area, and the area of ​​this circular area corresponds to the area S1 of the outer circumferential surface of the main section 201 perpendicular to the axial direction of the cover plate 2.

[0032] Similarly, the cross-section of the projecting section 202 perpendicular to the axial direction of the cover plate 2 is also a circular area. The outer edge of the projecting section 202 (the outer edge of the projecting section 202 extends along the axial direction of the cover plate 2 and forms the outer wall of the projecting section 202) forms this circular area, and the area of ​​this circular area corresponds to the area S2 of the outer circumferential surface of the projecting section 202 perpendicular to the axial direction of the cover plate 2.

[0033] Similarly, the cross-section of the inner wall of the housing body 1 perpendicular to the axial direction of the housing body 1 is also a circular area. The inner edge of the housing body 1 (which extends along the axial direction of the housing body 1 and forms the inner wall) forms this circular area, and the area of ​​this circular area corresponds to the area S3 of the inner circumferential surface of the housing body 1 perpendicular to the axial direction of the housing body 1.

[0034] Since the projecting section 202 is located on the inside of the inner wall of the housing body 1, the area S2 of the outer circumferential surface of the projecting section 202 perpendicular to the axial direction of the cover plate 2 is smaller than the area S3 of the inner circumferential surface of the housing body 1 perpendicular to the axial direction of the housing body 1, i.e. S2 ≤ S3.

[0035] In this embodiment, the following condition applies to the areas S1, S2 and S3: 1250 mm² 2 ≤ S1 / (S2 / S3) ≤ 2000 mm2 Within the specified area, the projecting section 202 of the cover plate 2 can be more easily inserted into the housing body 1, which facilitates the insertion of the cover plate 2 into the housing and reduces assembly difficulty, thereby improving the efficiency of the insertion process. Furthermore, after the cover plate 2 is inserted into the housing body 1, the gap between the outer wall of the projecting section 202 and the inner wall of the housing body 1 is not too large, and the offset of the cover plate 2 to the housing body is small. This allows the cover plate 2 to be positioned more centrally, and the contact area between the main section 201 of the cover plate 2 and the end face of the open end 101 on the housing body 1 is larger and more evenly distributed. This ensures the weld strength and weld yield between the cover plate 2 and the housing body 1, thus improving the overall quality of the cylindrical battery.

[0036] For example, the value of “S1 / (S2 / S3)” can be 1250 mm 2 , 1300 mm 2 , 1620 mm 2 , 1945 mm 2 , 2000 mm 2 etc.

[0037] Furthermore, the surface S1 of the outer circumferential surface of the main section 201 lies perpendicular to the axial direction of the cover plate 2 in the area of ​​1200 mm. 2 up to 2000 mm 2 .

[0038] The cross-section of the main section 201 perpendicular to the axial direction of the cover plate 2 is a circular area, and the area of ​​this circular area is the area S1 of the outer circumferential surface of the main section 201 perpendicular to the axial direction of the cover plate 2.

[0039] In this embodiment, the area S1 lies in the region of 1200 mm. 2 up to 2000 mm 2Within the aforementioned range of values, the area S1 is neither too large nor too small, thus ensuring that the roundness of the main section 201 is good, machining difficulties are reduced, the weld area of ​​the main section 201 facing the housing body 1 and the end face of the open end 101 is uniform and consistent, and the size of the weld area meets the requirements, thereby ensuring the weld strength and weld yield of both parts.

[0040] For example, the area S1 can be 1200 mm² 2 , 1460 mm 2 , 1760 mm 2 , 1870 mm 2 , 1910 mm 2 , 2000 mm 2 etc.

[0041] Furthermore, the area of ​​the outer circumferential surface S2 of the projection section 202 lies perpendicular to the axial direction of the cover plate 2 in the region of 1100 mm. 2 up to 2000 mm 2 ;

[0042] The cross-section of the projection section 202 perpendicular to the axial direction of the cover plate 2 is a circular area, and the area of ​​this circular area is the area S2 of the outer circumferential surface of the projection section 202 perpendicular to the axial direction of the cover plate 2.

[0043] In this embodiment, the area S2 is in the range of 1100 mm. 2 up to 2000 mm 2Within the aforementioned range of values, the area S2 is neither too large nor too small, and the projecting section 202 can be easily inserted into the housing body 1, which improves the efficiency of inserting the cover plate 2 and facilitates its assembly. Furthermore, after inserting the cover plate 2 onto the open end 101 of the housing body 1, the gap between the outer wall of the projecting section 202 and the cover plate 2 does not exhibit any significant alignment problems. Therefore, the weld area of ​​the main section 201 facing the housing body 1 and the end face of the open end 101 is uniform and consistent, and the size of the weld area meets the requirements, thus ensuring the weld strength and weld yield of both parts.

[0044] For example, the area S2 can be 1100 mm² 2 , 1350 mm 2 , 1460 mm 2 , 1680 mm 2, 1920 mm 2 , 2000 mm 2 etc.

[0045] Furthermore, the surface S3 of the inner circumferential surface of the housing body 1 lies perpendicular to the axial direction of the housing body 1 in the area of ​​1200 mm. 2 up to 2000 mm 2 .

[0046] The cross-section of the inner wall of the housing body 1, perpendicular to the axial direction of the housing body 1, is a circular area, and the area of ​​this circular area is the area S3 of the inner circumferential surface of the housing body 1, perpendicular to the axial direction of the housing body 1. If the value of the area S3 is too large, then after the insertion of the projecting section 202 into the housing body 1, the gap between the outer wall of the projecting section 202 and the inner wall of the housing body 1 is too large, which easily leads to a severe misalignment of the cover plate 2 relative to the housing body 1, causing the weld surfaces of the main section 201 facing the housing body 1 and the end face of the open end 101 to differ, the weld strength cannot be guaranteed, and the weld yield is low.If the value of the area S3 is too small, it will be difficult to insert the projection section 202 into the housing body 1, which impairs the efficiency of inserting the cover plate 2 into the housing and makes assembly more difficult.

[0047] In this embodiment, the area S3 lies in the region of 1200 mm. 2 up to 2000 mm 2Within the aforementioned range of values, the area S3 is neither too large nor too small, and the projecting section 202 can be easily inserted into the housing body 1, which improves the efficiency of inserting the cover plate 2 and facilitates assembly. Furthermore, after the cover plate 2 is placed on the open end 101 of the housing body 1, the gap between the outer wall of the projecting section 202 is not too large, and the cover plate 2 does not exhibit any significant alignment problems. Therefore, the weld area of ​​the main section 201, facing the housing body 1, and the end face of the open end 101 are uniform and consistent, and the size of the weld area meets the requirements, thus ensuring the weld strength and weld yield of both parts.

[0048] For example, the area S3 can be 1200 mm 2 , 1370 mm 2 , 1550 mm 2 , 1720 mm 2 , 1880 mm2 , 2000 mm 2 etc.

[0049] Furthermore, the ratio between the area S2 of the outer circumferential surface of the projection section 202 perpendicular to the axial direction of the cover plate 2 and the area S3 of the inner circumferential surface of the housing body 1 perpendicular to the axial direction of the housing body 1 is in the range of 0.95 to 1.

[0050] The ratio of areas S2 and S3 is related to the fit between the outer wall of the projection section 202 and the inner wall of the housing body 1. If the value of "S2 / S3" is too large, either area S2 is too large or area S3 is too small, which makes inserting the projection section 202 into the housing body 1 more difficult, impairs the efficiency of inserting the cover plate 2 into the housing, and complicates assembly.If the value of “S2 / S3” is too small, either the area S2 is too small or the area S3 is too large, which, after the insertion of the projecting section 202 into the housing body 1, leads to an excessively large gap between its outer wall and the inner wall of the housing body 1, causing the cover plate 2 to easily slip significantly relative to the housing body 1, resulting in an uneven weld seam between the side of the main section 201 facing the housing body 1 and the end face of the open end 101, the weld strength cannot be guaranteed, and the weld yield is low.

[0051] In this embodiment, the ratio of "S2 / S3" lies in the range of 0.95 to 1. Within the aforementioned ratio range, the value of "S2 / S3" is neither too high nor too low, and the projecting section 202 can be easily inserted into the housing body 1, which improves the efficiency of inserting the cover plate 2 and facilitates assembly. Furthermore, after the cover plate 2 is placed on the open end 101 of the housing body 1, the gap between the outer wall of the projecting section 202 and the housing body 1 is not too large, and the cover plate 2 does not exhibit any significant alignment problems. Therefore, the weld area of ​​the main section 201 facing the housing body 1 and the end face of the open end 101 is uniform and consistent, and the size of the weld area meets the requirements, thus ensuring the weld strength and weld yield of the two parts.

[0052] For example, the ratio of “S2 / S3” can be 0.95, 0.96, 0.97, 0.98, 0.99, 1, etc.

[0053] Furthermore, in the radial direction of the cover plate 2, the distance from one outer wall of the projection section 202 to the inner wall of the housing body 1 is L1 and the distance from the other outer wall of the projection section 202 to the inner wall of the housing body 1 is L2, where the following condition is met: 0.6≤L1 / L2≤1.4.

[0054] As in Fig.As shown in Figure 1, the radial direction of the cover plate 2 is the x-direction. When the cover plate 2 is placed on the open end 101, a certain gap is created between the outer wall of the projection section 202 and the inner wall of the housing body 1. Furthermore, in the x-direction, the distance from the outer wall of one side of the projection section 202 to the inner wall of the housing body 1 is L1, and the distance from the other side of the outer wall of the projection section 202 to the inner wall of the housing body 1 is L2. For example, considering the perspectives of Fig. 3 and Fig.4, the distance from the left outer wall of the projection section 202 to the inner wall of the housing body 1 L1 is and the distance from the right outer wall of the projection section 202 to the inner wall of the housing body 1 L2 is; of course, it is also possible that the distance from the right outer wall of the projection section 202 to the inner wall of the housing body 1 L1 is and the distance from the left outer wall of the projection section 202 to the inner wall of the housing body 1 L2 is.

[0055] If the ratio “L1 / L2” is too large or too small, the difference between the distances L1 and L2 will be too great, which can easily lead to a significant misalignment of the cover plate 2 relative to the housing body 1. This will cause the welding surfaces of the main section 201 facing the housing body 1 and the end face of the open end 101 to differ, resulting in insufficient weld strength and low weld yield. If the ratio “L1 / L2” is too small, the demands on the processing technology increase, which in turn increases the complexity of the process and processing costs.

[0056] In this embodiment, the ratio of distance L1 to distance L2 is in 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 to each other, and the difference between them is small. Furthermore, after the cover plate 2 is placed on the open end 101 of the housing body 1, the cover plate 2 is more centered and does not exhibit any significant alignment problems. Therefore, the weld area of ​​the main section 201, facing the housing body 1, and the end face of the open end 101 are uniform and consistent, and the size of the weld area meets the requirements, thus ensuring the weld strength and weld yield of the two parts. Moreover, the process is relatively simple, which helps to control processing costs.

[0057] 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.

[0058] Furthermore, in the radial direction of the cover plate 2, the distance from one outer wall of the projection section 202 to the inner wall of the housing body 1 is L1 and the distance from the other outer wall of the projection section 202 to the inner wall of the housing body 1 is L2, where L1 is in the range of 0.02 mm to 0.5 mm and L2 is in the range of 0.02 mm to 0.5 mm.

[0059] As in Fig.As shown in Figure 1, the radial direction of the cover plate 2 is the x-direction. When the cover plate 2 is placed on the open end 101, a certain gap is created between the outer wall of the projecting section 202 and the inner wall of the housing body 1. Furthermore, in the x-direction, the distance from the outer wall of one side of the projecting section 202 to the inner wall of the housing body 1 is L1, and the distance from the other side of the outer wall of the projecting section 202 to the inner wall of the housing body 1 is L2.

[0060] If the distance L1 is too large, the gap between the outer wall of the projecting section 202 and the inner wall of the housing body 1 is too large. This can easily lead to a significant misalignment of the cover plate 2 relative to the housing body 1, causing the weld surfaces of the main section 201 facing the housing body 1 and the end face of the open end 101 to differ. This compromises weld strength and results in a low weld yield. If the distance L1 is too small, it becomes difficult to insert the projecting section 202 into the housing body 1, impairing the efficiency of inserting the cover plate 2 into the housing and complicating assembly.

[0061] In this embodiment, the distance L1 is in the range of 0.02 mm to 0.5 mm. Within this range, L1 is neither too large nor too small, and the projecting section 202 can be easily inserted into the housing body 1, which improves the efficiency of inserting the cover plate 2 and facilitates assembly.

[0062] Furthermore, after the cover plate 2 is placed on the open end 101 of the housing body 1, the gap between the outer wall of the projection section 202 and the housing body 1 is not too large, and the cover plate 2 does not have any serious alignment problems, so that the weld area of ​​the main section 201 facing the housing body 1 and the end face of the open end 101 is uniform and consistent, and the size of the weld area meets the requirements, thus ensuring the weld strength and weld yield of the two parts.

[0063] For example, the distance L1 can be 0.02 mm, 0.04 mm, 0.1 mm, 0.24 mm, 0.3 mm, 0.46 mm, 0.5 mm, etc.

[0064] If the distance L2 is too large, the gap between the outer wall of the projecting section 202 and the inner wall of the housing body 1 is also too large at this point. This can easily lead to a significant misalignment of the cover plate 2 relative to the housing body 1, causing the weld surfaces of the main section 201 facing the housing body 1 and the end face of the open end 101 to differ. This compromises weld strength and results in a low weld yield. If the distance L2 is too small, it becomes difficult to insert the projecting section 202 into the housing body 1, which impairs the efficiency of inserting the cover plate 2 into the housing and complicates assembly.

[0065] In this embodiment, the distance L2 is in the range of 0.02 mm to 0.5 mm. Within this range, L2 is neither too large nor too small, and the projecting section 202 can be easily inserted into the housing body 1, which improves the efficiency of inserting the cover plate 2 and simplifies assembly. Furthermore, after the cover plate 2 is placed on the open end 101 of the housing body 1, the gap between the outer wall of the projecting section 202 and the housing body 1 is not too large, and the cover plate 2 does not exhibit any significant alignment problems. Therefore, the weld area of ​​the main section 201 facing the housing body 1 and the end face of the open end 101 is uniform and consistent, and the size of the weld area meets the requirements, thus ensuring the weld strength and weld yield of the two parts.

[0066] For example, the distance L2 can be 0.02 mm, 0.05 mm, 0.12 mm, 0.26 mm, 0.35 mm, 0.43 mm, 0.5 mm, etc.

[0067] Furthermore, in the radial direction of the cover plate 2, the distance from one outer wall of the projection section 202 to the inner wall of the housing body 1 is L1 and the distance from the other outer wall of the projection section 202 to the inner wall of the housing body 1 is L2, where L1=L2 and the following condition is met: 1700 mm 2 ≤ S1 / (S2 / S3) ≤ 2000 mm 2 .

[0068] In the x-direction, the distance from the outer wall of one side of the projection section 202 to the inner wall of the housing body 1 is L1, and the distance from the other side of the outer wall of the projection section 202 to the inner wall of the housing body 1 is L2. In this embodiment, L1 = L2. When the cover plate 2 is placed on the housing body 1, the projection section 202 is centered. The gap between the outer wall of the projection section 202 and the inner wall of the housing body 1 is uniform in the circumferential direction. At this point, the surfaces S2 and S3 can be relatively close to each other, i.e., the ratio "S2 / S3" can be smaller. Under the condition 1700 mm 2 ≤ S1 / (S2 / S3) ≤ 2000 mm 2It is further ensured that the projecting section 202 can be easily inserted into the housing body 1, the assembly effort is low, the cover plate 2 has a high insertion efficiency and is arranged centrally to the housing body 1, so that the welding surface of the cover plate 2 facing the housing body 1 and the end face of the open end 101 is uniform and consistent and the size of the welding surface meets the requirements, thereby ensuring the weld strength and the weld yield of the two parts.

[0069] For example, “S1 / (S2 / S3)” can be 1700 mm 2 , 1910 mm 2 , 2000 mm 2 etc.

[0070] In other embodiments, the distance in the radial direction of the cover plate 2 from one outer wall of the projection section 202 to the inner wall of the housing body 1 is L1, and the distance from the other outer wall of the projection section 202 to the inner wall of the housing body 1 is L2, and L1 > L2 or L1 < L2, where the following condition is met: 1250 mm 2 ≤ S1 / (S2 / S3) ≤ 1650 mm 2 , in order to meet different setting requirements.

[0071] In this embodiment, the distance L1 is not equal to the distance L2, there is a significant misalignment of the cover plate 2 relative to the housing body 1, and the gap between the outer wall of the projection section 202 and the inner wall of the housing body 1 is uneven. At this point, the ratio "S2 / S3" must be larger to avoid insufficient weld strength at the point with the relatively large gap between the outer wall of the projection section 202 and the inner wall of the housing body 1. That is, the following condition must be met: 1250 mm 2 ≤S1 / (S2 / S3) ≤ 1650 mm 2Within this range of values, it can be ensured that the projecting section 202 can be easily inserted into the housing body 1, so that the assembly effort is low and the cover plate 2 has a high insertion efficiency and the welding surface of the main section 201 facing the housing body 1 and the end face of the open end 101 is uniform and consistent, thus ensuring the weld strength and the weld yield of the two parts.

[0072] For example, “S1 / (S2 / S3)” can be 1250 mm 2 , 1340 mm 2 , 1490 mm 2 , 1570 mm 2 , 1650 mm 2 etc.

[0073] Furthermore, the height of the projection section (202) located in the housing body (1) along the axial direction of the cover plate (2) is H and H is in the range of 0.2 mm to 2 mm.

[0074] The projecting section 202 is a cylindrical structure with a specific axial height, wherein the axial direction of the projecting section 202 coincides with the axial direction of the cover plate 2 (as shown in Fig. (1 shown in the y-direction). When the projection section 202 is inserted into the housing body 1, the projection section 202 is located inside the housing body 1 and has the height H, as shown in Fig. 6 shown.

[0075] If the height H of the projection section 202 is too great, the machining time for inserting the projection section 202 into the housing body 1 increases, leading to reduced efficiency when inserting the cover plate 2 into the housing. If the height H of the projection section 202 is too small, the projection section 202 can easily slip out again after insertion into the housing body 1, making the positioning of the cover plate 2 and the housing body 1 more difficult and impairing assembly.

[0076] In this embodiment, the height H of the protruding section 202 is in the range of 0.2 mm to 2 mm. Within this range, the height H of the protruding section 202 is neither too high nor too low, which facilitates quick insertion of the protruding section 202 into the housing body 1 and improves the efficiency of inserting the cover plate 2 into the housing. Simultaneously, the cover plate 2 and the housing body 1 can be reliably positioned after the protruding section 202 has been inserted into the housing body 1, which simplifies subsequent welding operations and increases assembly efficiency.

[0077] For example, the height of the protrusion section 202 can be 0.2 mm, 0.5 mm, 0.8 mm, 1.2 mm, 1.6 mm, 1.8 mm, 2 mm, etc.

[0078] Furthermore, the outer wall of the projection section 202 is provided with a projection 203, wherein the projection 203 is arranged along the radial direction and at least a part of the outer wall of the projection section 203 abuts the inner wall of the housing body 1, wherein the following condition is met: 1500 mm 2 ≤ S1 / (S2 / S3) ≤ 2000 mm 2 .

[0079] As in the Fig.As shown in Figures 5 to 9, the outer wall of the projection section 202 is provided with a projection 203 that extends from the outer wall of the projection section 202 and is arranged radially. At least a portion of the outer wall of the projection 203 rests against the inner wall of the housing body 1. That is, at least a portion of the outer wall of the projection section 202 does not directly contact the inner wall of the housing body 1, but rather via the projection 203. In this embodiment, the entire outer wall of the projection section 202 does not directly contact the inner wall of the housing body 1, but rather rests against the inner wall of the housing body 1 via the projection 203.

[0080] When the projection section 202 is inserted into the housing body 1, the outer wall of the projection 203 abuts the inner wall of the housing body 1. By arranging a projection 203 and having its outer wall abut the inner wall of the housing body 1, the projection section 202 can be more easily centered, thereby centering the cover plate 2 relative to the housing body 1, provided the following condition is met: 1500 mm 2 ≤ S1 / (S2 / S3) ≤ 2000 mm 2 Within the aforementioned range of values, the projecting section 202 can be more easily inserted into the housing body 1, simplifying assembly and making the insertion of the cover plate 2 into the housing more efficient. Furthermore, the welding surface of the main section 201 facing the housing body 1 and the end face of the open end 101 is as large and uniform as possible to ensure the weld strength and weld yield of both parts.

[0081] For example, “S1 / (S2 / S3)” can be 1500 mm 2 , 1650 mm 2 , 1760 mm 2 , 1880 mm 2 , 1940 mm 2 , 2000 mm 2 etc.

[0082] In other embodiments, the outer wall of the projection 203 can abut the inner wall of the housing body 1, and at this time a part of the outer wall of the projection section 202 abuts the inner wall of the housing body 1 through the projection 203.

[0083] Furthermore, at least two projections 203 are provided along the circumferential direction of the projection section 202, wherein at least two projections 203 are spaced apart from each other and the ratio between the area S2 of the outer circumferential surface of the projection section 202 perpendicular to the axial direction of the cover plate 2 and the area S3 of the inner circumferential surface of the housing body 1 perpendicular to the axial direction of the housing body 1 is in the range of 0.97 to 1.

[0084] The projection 203 is provided on the outer wall of the projection section 202, and depending on the requirements, the projection 203 can be a continuous or a discontinuous projection. In this embodiment, the projection 203 is a discontinuous projection, and at least two projections 203 are provided. For example, there can be 2, 3, 4, 6, etc. At least two projections 203 are spaced apart from each other, and the exact number of projections 203 can be selected according to the circumference of the projection section 202. In particular, in this embodiment, there are 8 projections 203, with adjacent projections 203 being spaced apart from each other.

[0085] Optionally, the distance between adjacent projections 203 is equal in the circumferential direction, so that the position of the cover plate 2 is more centered relative to the housing body 1 and the weld surface of the main section 201 facing the housing body 1 and the end face of the open end 101 is uniform to ensure the weld strength and weld yield of both.

[0086] This arrangement of the projection 203 facilitates its installation in the housing. The ratio between the area S2 of the outer circumferential surface of the projection section 202, perpendicular to the axial direction of the cover plate 2, and the area S3 of the inner circumferential surface of the housing body 1, perpendicular to the axial direction of the housing body 1, is currently in the range of 0.97 to 1. Within the aforementioned ratio range, the value of "S2 / S3" is neither too large nor too small, and the projection section 202 can be easily inserted into the housing body 1, which improves the efficiency of inserting the cover plate 2 and simplifies assembly.Furthermore, after the cover plate 2 is placed on the open end 101 of the housing body 1, the gap between the outer wall of the projection section 202 and the housing body 1 is not too large, and the cover plate 2 does not have any serious alignment problems, so that the weld area of ​​the main section 201 facing the housing body 1 and the end face of the open end 101 is uniform and consistent, and the size of the weld area meets the requirements, thus ensuring the weld strength and weld yield of the two parts.

[0087] For example, the ratio of “S2 / S3” can be 0.97, 0.975, 0.983, 0.994, 1, etc.

[0088] In other embodiments, the projection 203 is a continuous projection arranged circumferentially along the projection section 202, and the ratio between the area S2 of the outer circumferential surface of the projection section 202 perpendicular to the axial direction of the cover plate 2 and the area S3 of the inner circumferential surface of the housing body 1 perpendicular to the axial direction of the housing body 1 is in the range of 0.95 to 0.97. In this embodiment, the projection 203 is an annular structure that surrounds the projection section 202. Compared to interrupted projections, this continuous projection somewhat impairs the efficiency of inserting the cover plate 2 into the housing, as it makes it more difficult to align the projection section 202 with the housing body 1. However, this continuous projection is easier to form, which increases processing efficiency and reduces processing costs.

[0089] To facilitate the installation of the continuous projection 203 into the housing, the ratio between the area S2 of the outer circumferential surface of the projection section 202 perpendicular to the axial direction of the cover plate 2 and the area S3 of the inner circumferential surface of the housing body 1 perpendicular to the axial direction of the housing body 1 is limited; that is, the ratio between the area S2 of the outer circumferential surface of the projection section 202 perpendicular to the axial direction of the cover plate 2 and the area S3 of the inner circumferential surface of the housing body 1 perpendicular to the axial direction of the housing body 1 is in the range of 0.95 to 0.97. A certain gap exists between the outer wall of the projection section 202 and the inner wall of the housing body 1, which facilitates installation in the housing.Within the aforementioned ratio range, the value of "S2 / S3" is neither too high nor too low, and the projecting section 202 can be easily inserted into the housing body 1. This improves the efficiency of inserting the cover plate 2, facilitates assembly, and also prevents significant deformation of the housing body. Furthermore, after the cover plate 2 is placed on the open end 101 of the housing body 1, the gap between the outer wall of the projecting section 202 and the housing body 1 is not too large, and the cover plate 2 does not exhibit any serious alignment problems. Therefore, the weld area of ​​the main section 201 facing the housing body 1 and the end face of the open end 101 is uniform and consistent, and the size of the weld area meets the requirements, thus ensuring the weld strength and weld yield of both parts.

[0090] For example, the ratio of “S2 / S3” can be 0.95, 0.955, 0.96, 0.962, 0.97, etc.

[0091] Furthermore, the number of projections 203 is an even number, wherein the even number of projections 203 are arranged symmetrically in pairs radially to the projection section 202.

[0092] To make the overall structure of the projection section 202 more symmetrical and to enable quick alignment of the projection section 202 with the housing body 1, the number of projections 203 is an even number, for example: the number of projections 203 is 2, 4, 6, 8, etc., and the even number of projections 203 is arranged symmetrically in pairs with respect to the radial direction of the projection section 202. As shown in Fig. As shown in Figure 9, in this embodiment eight projections 203 are provided, which are arranged symmetrically in pairs with respect to the radial direction of the projection section 202.

[0093] Furthermore, in the axial direction of the cover plate 2, the projection 203 is arranged below the center of the projection section 202; the ratio between the area S2 of the outer circumferential surface of the projection section 202 perpendicular to the axial direction of the cover plate 2 and the area S3 of the inner circumferential surface of the housing body 1 perpendicular to the axial direction of the housing body 1 is in the range of 0.95 to 0.98.

[0094] In the axial direction of the cover plate 2 (y-direction in Fig.1) The midpoint of the height dimension of the projection section 202 is located at the center of the projection section 202, and the dimensions above the center of the projection section 202 are equal to the dimensions below the center. The section above the center of the projection section 202 is the upper part of the projection section 202, and the section below the center of the projection section 202 is the lower part of the projection section 202. As in Fig. As shown in Figure 7, position a is the middle position of the leading section 202, position b is the position above the middle of the leading section 202 and position c is the position below the middle of the leading section 202.

[0095] The projection 203 is located below the center of the projection section 202, i.e., the projection 203 is positioned at the lower edge of the projection section 202. When inserting the projection section 202 into the housing body 1, the projection 203 can be quickly positioned with the housing body 1, thus ensuring precise insertion of the projection section 202 and improving the efficiency of inserting the cover plate 2 into the housing.

[0096] To facilitate the installation of the projection 203 into the housing, the ratio between the area S2 of the outer circumferential surface of the projection section 202 perpendicular to the axial direction of the cover plate 2 and the area S3 of the inner circumferential surface of the housing body 1 perpendicular to the axial direction of the housing body 1 is limited. This means that the ratio between the area S2 of the outer circumferential surface of the projection section 202 perpendicular to the axial direction of the cover plate 2 and the area S3 of the inner circumferential surface of the housing body 1 perpendicular to the axial direction of the housing body 1 is in the range of 0.95–0.98. Within the aforementioned ratio range, the value of "S2 / S3" is neither too large nor too small, and the projection section 202 can be easily inserted into the housing body 1. This improves the efficiency of inserting the cover plate 2, facilitates assembly, and also prevents significant deformation of the housing body.Furthermore, after the cover plate 2 is placed on the open end 101 of the housing body 1, the gap between the outer wall of the projection section 202 and the housing body 1 is not too large, and the cover plate 2 does not have any serious alignment problems, so that the weld area of ​​the main section 201 facing the housing body 1 and the end face of the open end 101 is uniform and consistent, and the size of the weld area meets the requirements, thus ensuring the weld strength and weld yield of the two parts.

[0097] For example, the ratio of “S2 / S3” can be 0.95, 0.955, 0.96, 0.972, 0.98, etc.

[0098] In other embodiments, depending on different configuration requirements, a projection 203 is arranged centrally in the projection section 202 along the axial direction of the projection section 202, and the ratio between the area S2 of the outer circumferential surface of the projection section 202 perpendicular to the axial direction of the cover plate 2 and the area S3 of the inner circumferential surface of the housing body 1 perpendicular to the axial direction of the housing body 1 is in the range of 0.98 to 1. When the projection section 202 is inserted into the housing body 1, the lower part of the projection section 202 slides quickly into the housing and is then positioned with the housing body 1 by the projection 203, which facilitates the quick insertion and locking of the projection section 202 into the housing body 1 and can also improve the efficiency of inserting the cover plate 2 into the housing.

[0099] At this point, the projecting section 202 can be more easily installed in the housing. The ratio between the area S2 of the outer circumferential surface of the projecting section 202 perpendicular to the axial direction of the cover plate 2 and the area S3 of the inner circumferential surface of the housing body 1 perpendicular to the axial direction of the housing body 1 can be in the range of 0.98 to 1. Within the aforementioned ratio range, the value of "S2 / S3" is neither too large nor too small, and the projecting section 202 can be easily inserted into the housing body 1, which improves the efficiency of inserting the cover plate 2 and facilitates assembly.Furthermore, after the cover plate 2 is placed on the open end 101 of the housing body 1, the gap between the outer wall of the projection section 202 and the housing body 1 is not too large, and the cover plate 2 does not have any serious alignment problems, so that the weld area of ​​the main section 201 facing the housing body 1 and the end face of the open end 101 is uniform and consistent, and the size of the weld area meets the requirements, thus ensuring the weld strength and weld yield of the two parts.

[0100] For example, the ratio of “S2 / S3” can be 0.98, 0.99, 0.996, 1, etc.

[0101] In this embodiment, the projections 203 are arranged in the upper, middle and lower regions of the projection section 202, as shown in Fig.6 shown, where this projection 203 is relatively simple, easy to manufacture and shape, and contributes to reducing manufacturing costs.

[0102] Furthermore, the outer wall of the projection (203) is an arc-shaped surface.

[0103] The outer wall of the projection 203 abuts the inner wall of the housing body 1, and the inner wall of the housing body 1 is an arc-shaped structure. To improve the fit between the outer wall of the projection 203 and the inner wall of the housing body 1, the outer wall of the projection 203 has an arc-shaped surface.

[0104] Optionally, the outer wall of the projection 203 has the same curvature as the inner wall of the housing body 1, so that the outer wall of the projection 203 fits better against the inner wall of the housing body 1, which improves the contact and positioning between the projection 203 and the housing body 1, while at the same time making it easier to insert the projection 203 into the housing and improving the efficiency of inserting the cover plate 2 into the housing.

[0105] Furthermore, in the radial direction of the projection section 202, the thickness t of the projection 203 is in the range of 0.5 mm to 4 mm.

[0106] The projection 203 protrudes from the outer wall of the projection section 202. Along the radial direction of the projection section 202, the dimension of the projection 203 protruding from the projection section 202 corresponds to the thickness of the projection 203, as shown in Fig. 6 shown, and the thickness of the projection 203 is t.

[0107] If the thickness t of the projection 203 is too large, the projection 203 expands slightly when the projection section 202 is inserted into the housing body 1, leading to significant deformation of the housing body 1 and thus impairing the quality of the battery product. If the thickness t of the projection 203 is too small, the projection 203 cannot rest against the inner wall of the housing body 1, and the projection section 202 cannot be centered, i.e., the cover plate 2 is not positioned centrally to the housing body 1.

[0108] In this embodiment, the thickness t of the projection 203 is in the range of 0.5 mm to 4 mm. Within the aforementioned range, the thickness t of the projection 203 must be neither too large nor too small, so that the design and positioning of the projection 203 and the housing body 1 can be achieved such that the projection section 202 is arranged centrally and the cover plate 2 is centered relative to the housing body 1, and no deformation of the housing body 1 occurs, thus ensuring the quality of the battery product.

[0109] For example, the thickness t of the projection 203 can be 0.5 mm, 0.7 mm, 1.2 mm, 2.8 mm, 3.5 mm, 4 mm, etc.

[0110] Furthermore, in the axial direction of the projection section 202, the height h of the projection 203 lies in the range of 0.2 mm to 1.5 mm.

[0111] The projection 203 protrudes from the outer wall of the projection section 202. Along the axial direction of the projection section 202, the projection 203 has a specific height, as shown in Fig. 6 shown, and the height of the projection 203 is h.

[0112] If the height h of the projection 203 is too large, it becomes difficult to insert the projection section 202 into the housing body 1, which impairs the efficiency of inserting the cover plate 2 into the housing. If the height h of the projection 203 is too small, the effect of the installation and positioning of the projection 203 and the housing body 1 is average.

[0113] In this embodiment, the height h of the projection 203 is in the range of 0.2 mm to 1.5 mm. Within the aforementioned range, the height h of the projection 203 is neither too high nor too low, thus ensuring proper contact and positioning between the projection 203 and the housing body 1, so that the projection section 202 and the cover plate 2 are centered and the efficient insertion of the cover plate 2 into the housing is guaranteed.

[0114] Furthermore, the diameter of the outer circumferential surface of the outer wall of the projection 203 is d1 and the diameter of the inner circumferential surface of the inner wall of the housing body 1 is d2, where the ratio d1 / d2 is in the range of 1 to 1.05.

[0115] As in the Fig. 2 and Fig.As shown in Figure 9, the outer wall of the projection 203 is designed as an arcuate surface to fit the inner wall of the housing body 1. Perpendicular to the axial direction of the cover plate 2, the outer wall of the projection 203 forms a segment of a circular arc, the diameter of which is d1, i.e., the diameter d1 of the outer circumferential surface on which the outer wall of the projection 203 is located. In a direction perpendicular to the axial direction of the housing body 1, a circular surface is formed on the inner wall of the housing body 1, the diameter of which is d2, i.e., the diameter d2 of the inner circumferential surface on which the inner wall of the housing body 1 is located.

[0116] In this embodiment, the ratio d1 / d2 is in the range of 1 to 1.05. Within this ratio range, the diameters d1 and d2 are relatively close to each other, so that the projection 203 forms an interference fit with the inner wall of the housing body 1, which ensures that the outer wall of the projection 203 rests against the inner wall of the housing body 1 and improves the fit between the cover plate 2 and the housing body 1.

[0117] For example, the ratio d1 / d2 can be 1, 1.01, 1.02, 1.03, 1.04 or 1.05.

[0118] Furthermore, the outer circumference diameter d3 of the main section 201 is in the range of 40 mm to 50 mm and the number of provided projections 203 is 2 to 16.

[0119] As in Fig.As shown in Figure 9, a circular surface perpendicular to the axial direction of the cover plate 2 is formed on the outer wall of the main section 201 of the cover plate 2, wherein the diameter of the circular surface is d3, i.e., the outer circumferential diameter d3 of the main section 201. In this embodiment, the diameter d3 is in the range of 40 mm to 50 mm and, for example, the diameter d3 can be 40 mm, 42 mm, 45 mm, 48 mm or 50 mm.

[0120] Under this condition, the number of projections 203 can be specified as 2 to 16, and for example the number of projections 203 can be specified as 2, 3, 6, 8, 11, 14 or 16.

[0121] The number of protrusions 203 provided should not be too high, otherwise it will be difficult to align the protrusion section 202 with the housing body 1. Furthermore, an excessive number of protrusions 203 can slightly stretch the housing body 1 when the protrusion section 202 is inserted into it, which can lead to deformation of the housing body 1 and thus impair battery quality.

[0122] Optionally, the number of provided projections 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 equal to 4 and the number of projections 203 is 8.

[0123] Furthermore, the larger the diameter d3 of the main section 201, the more projections 203 are required. This is because, as the diameter d3 of the main section 201 increases, the positioning of the cover plate 2 and the housing body 1 becomes more difficult during assembly, and therefore more projections 203 are needed to facilitate the positioning of the projections 202 and the housing body 1.

[0124] This embodiment further provides a cylindrical battery comprising the housing described in the embodiment above. With this type of cylindrical battery, the projecting section 202 of the cover plate 2 can be more easily inserted into the housing body 1, which facilitates the insertion of the cover plate 2 into the housing and reduces the assembly difficulty, thereby improving the efficiency of inserting the cover plate 2.Furthermore, after inserting the cover plate 2 into the housing body 1, the offset of the cover plate 2 to the housing body 1 is small, which allows the cover plate 2 to be arranged more centrally and the contact area between the main section 201 of the cover plate 2 and the end face of the open end 101 on the housing body 1 is larger and more evenly distributed, which ensures the weld strength and weld yield between the cover plate 2 and the housing body 1 and thus improves the overall quality of the cylindrical battery.

[0125] Naturally, this cylindrical battery also contains other structures that are present in existing cylindrical batteries and will not be explained in detail here.

[0126] The assembly process of the cover plate 2 of the cylindrical battery and the housing body 1 in this embodiment is described below with reference to the accompanying drawings: First, the projecting section 202 of the cover plate 2 is aligned with the open end 101 of the housing body 1 and inserted into the housing body 1. Since the projection 203 is located near the lower part of the projecting section 202, it penetrates the housing body 1 first, thus positioning the projecting section 202. The outer wall of the projection 203 fits snugly against the inner wall of the housing body 1. The projecting section 202 is inserted further into the housing body 1 until the side of the main section 201 facing the housing body 1 touches the end face of the open end 101. Now the projecting section 202 is centered relative to the housing body 1, i.e., the cover plate 2 is centered relative to the housing body 1.

[0127] Subsequently, the side of the main section 201 facing the housing body 1 is welded to the end face of the open end 101, thus completing the assembly of the cover plate 2 and the housing body 1.

[0128] The following tests were carried out regarding the weld strength between the cover plate of the cylindrical battery and the housing body, as well as the difficulty of inserting the cover plate into the housing: Table 1 Serial number S1(mm 2 ) Whether the promontory section has an elevated section S2 / S3 S1 / (S2 / S3) weld strength Whether it can be inserted into the housing Example 1 1520 Yes 0,99 1540,5 OK OK Example 2 2000 Yes 1,00 2000,0 OK OK Example 3 1700 Yes 1,00 1700,0 OK OK Example 4 1870 Yes 0,98 1901,2 OK OK Example 5 1660 Yes 0,99 1674,4 OK OK Example 6 1810 Yes 0,95 1895,7 OK OK Example 7 1590 Yes 0,97 1639,2 OK OK Example 8 1915 Yes 0,98 1954,1 OK OK Example 9 1320 No 0,97 1361,9 OK OK Example 10 1380 No 0,96 1433,1 OK OK Example 11 1200 No 0,96 1252,2 OK OK Example 12 1260 No 0,98 1287,0 OK OK Comparative example 1 1998 Yes 0,95 2110,1 NG OK Comparative example 2 1206 Yes 0,99 1216,1 OK NG

[0129] The test data in Table 1 above show the following: In embodiments 1 to 12, the area S2 of the outer circumferential surface of the projection section 202 perpendicular to the axial direction of the cover plate 2 and the area S3 of the inner circumferential surface of the housing body 1 perpendicular to the axial direction of the housing body 1 satisfy the condition S2 ≤ S3, where the ratio S2 / S3 is in the range of 0.95 to 1. If the value of “S1 / (S2 / S3)” is in the range of 1250 mm 2 ≤ S1 / (S2 / S3) ≤ 2000 mm 2 The cover plate 2 can be easily inserted into the housing; assembly is simple and the insertion process is highly efficient. After the cover plate 2 is inserted into the housing, the weld strength between the cover plate 2 and the housing body 1 meets the requirements, and the cylindrical batteries manufactured with this housing type exhibit high product quality.

[0130] In comparative examples 1 and 2, the following conditions apply to the area S2 of the outer circumferential surface of the projection section 202 perpendicular to the axial direction of the cover plate 2 and to the area S3 of the inner circumferential surface of the housing body 1 perpendicular to the axial direction of the housing body 1: S2 ≤ S3, where the ratio S2 / S3 is in the range of 0.95 to 1. However, the value of “S1 / (S2 / S3)” exceeds the range of 1250 mm. 2 ≤ S1 / (S2 / S3) ≤ 2000 mm 2 Although the cover plate 2 can be inserted into the housing in comparison example 1, the weld strength between cover plate 2 and housing body 1 does not meet the requirements. In comparison example 2, while the weld strength is sufficient, cover plate 2 cannot be used there, and the cylindrical batteries produced with this housing type exhibit low yield and poor product quality.

[0131] Although the embodiments of the present application are described in conjunction with the figures, the person skilled in the art may make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations are all within the scope defined by the attached claims.

Claims

[1] Housing, characterized by , that it includes the following: a housing body (1) wherein at least one end is an open end (101); a cover plate (2) covering the open end (101), wherein the cover plate (2) comprises a main section (201) and a projecting section (202), wherein the projecting section (202) is located on the side of the main section (201) facing the housing body (1), the projecting section (202) is at least partially located within the housing body (1), and the main section (201) is connected to the end face of the open end (101) on the side facing the housing body (1); wherein in the radial direction of the cover plate (2) the distance from one outer wall of the projection section (202) to the inner wall of the housing body (1) is L1 and the distance from the other outer wall of the projection section (202) to the inner wall of the housing body (1) is L2, wherein L1 is in the range of 0.02 mm to 0.5 mm and L2 is in the range of 0.02 mm to 0.5 mm. [2] Housing according to claim 1, characterized by , that the area of ​​the outer circumferential surface of the main section (201) perpendicular to the axial direction of the cover plate (2) is S1, the area of ​​the outer circumferential surface of the projection section (202) perpendicular to the axial direction of the cover plate (2) is S2, the area of ​​the inner circumferential surface of the housing body (1) perpendicular to the axial direction of the housing body (1) is S3, where S2 ≤ S3 and the following condition is met: 1250 mm 2 ≤ S1 / (S2 / S3) ≤ 2000 mm 2 . [3] Housing according to claim 1, characterized bythat L1 and L2 meet the following conditions: 0.6≤L1 / L2≤1.

4. [4] Housing according to claim 2, characterized by , that if L1 = L2, then: 1700mm2≤S1 / (S2 / S3)≤2000mm2. [5] Housing according to claim 2, characterized by , that if L1 > L2 or L1 < L2, then: 1250 mm 2 ≤ S1 / (S2 / S3) ≤1650 mm 2 . [6] Housing according to claim 1, characterized by , that the height of the projection section (202) located in the housing body (1) along the axial direction of the cover plate (2) is H and H is in the range of 0.2 mm to 2 mm. [7] Housing according to claim 2, characterized by , that the surface S1 of the outer circumferential surface of the main section (201) is perpendicular to the axial direction of the cover plate (2) in the area of ​​1200 mm 2 up to 2000 mm 2 lies; that the surface S2 of the outer circumferential surface of the projection section (202) is perpendicular to the axial direction of the cover plate (2) in the area of ​​1100 mm 2 up to 2000 mm 2 lies; that the surface S3 of the inner circumferential surface of the housing body (1) is perpendicular to the axial direction of the housing body (2) in the area of ​​1200 mm 2 up to 2000 mm 2 lies; that the ratio between the area S2 of the outer circumferential surface of the projection section (202) perpendicular to the axial direction of the cover plate (2) and the area S3 of the inner circumferential surface of the housing body (1) perpendicular to the axial direction of the housing body (1) is in the range of 0.95 to 1. [8] Housing according to any one of claims 1 to 7, characterized by, that the outer wall of the projection section (202) is provided with a projection (203), wherein the projection (203) is arranged along the radial direction and at least a part of the outer wall of the projection section (203) abuts the inner wall of the housing body (1), wherein the following condition is met: 1500 mm 2 ≤S1 / (S2 / S3)≤ 2000 mm 2 . [9] Housing according to claim 8, characterized by , that the projection (203) is a continuous projection arranged along the circumferential direction of the projection section (202) and the ratio between the area S2 of the outer circumferential surface of the projection section (202) perpendicular to the axial direction of the cover plate (2) and the area S3 of the inner circumferential surface of the housing body (1) perpendicular to the axial direction of the housing body (1) is in the range of 0.95 to 0.

97. [10] Housing according to claim 8, characterized by, that at least two projections (203) are provided along the circumferential direction of the projection section (202), wherein at least two projections (203) are spaced apart from each other and the ratio between the area S2 of the outer circumferential surface of the projection section (202) perpendicular to the axial direction of the cover plate (2) and the area S3 of the inner circumferential surface of the housing body (1) perpendicular to the axial direction of the housing body (1) is in the range of 0.97 to 1. [11] Housing according to claim 10, characterized by , that the distance between adjacent projections (203) is the same in the circumferential direction. [12] Housing according to claim 10, characterized by , that the number of projections (203) is an even number, wherein the even number of projections (203) are arranged symmetrically in pairs radially to the projection section (202). [13] Housing according to claim 8, characterized by, that in the axial direction of the cover plate (2) the projection (203) is arranged below the center of the projection section (202); the ratio between the area S2 of the outer circumferential surface of the projection section (202) perpendicular to the axial direction of the cover plate (2) and the area S3 of the inner circumferential surface of the housing body (1) perpendicular to the axial direction of the housing body (1) is in the range of 0.95 to 0.

98. [14] Housing according to claim 8, characterized by , that in the axial direction of the projection section (202) the projection (203) is arranged in the middle of the projection section (202); the ratio between the area S2 of the outer circumferential surface of the projection section (202) perpendicular to the axial direction of the cover plate (2) and the area S3 of the inner circumferential surface of the housing body (1) perpendicular to the axial direction of the housing body (1) is in the range of 0.98 to 1. [15] Housing according to claim 8, characterized by, that the outer wall of the projection (203) is an arc-shaped surface. [16] Housing according to claim 8, characterized by , that in the radial direction of the projection section (202) the thickness t of the projection (203) is in the range of 0.5 mm to 4 mm; and that in the axial direction of the projection section (202) the height h of the projection (203) is in the range of 0.2 mm to 1.5 mm. [17] Housing according to claim 8, characterized by , that the diameter of the outer circumferential surface of the outer wall of the projection (203) is d1 and the diameter of the inner circumferential surface of the inner wall of the housing body (1) is d2, wherein the ratio d1 / d2 is in the range of 1 to 1.

05. [18] Housing according to claim 8, characterized by , that the outer circumference diameter d3 of the main section (201) is in the range of 40 mm to 50 mm and the number of provided projections (203) is 2 to 16. [19] Cylindrical battery, characterized bythat it comprises a housing according to any one of claims 1 to 18.

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