Batteries and electronic devices

Abstract

Provided are a battery and electronic device that can prevent laser irradiation to an electrode assembly when sealing and welding an exterior case of the battery, avoid damage to the electrode assembly, and ensure product yield. [Solution] The device includes an outer case and a cover plate, a portion of the cover plate adjacent to the edge of which protrudes toward the internal space of the outer case to form a boss, and a groove is included on one side of the boss away from the internal space of the outer case, a portion of the cover plate located radially outward of the boss forms a connecting edge, the boss is embedded in the opening, and the connecting edge overlaps with the end of the outer case, and there is a weld mark formed by welding between the connecting edge and the end of the outer case, and the cross-sectional size of the weld mark gradually decreases from the radial outside to the radial inside of the cover plate, the inner wall of the groove includes a bottom wall and an outer groove wall surrounding the outer periphery of the bottom wall, and a punched groove formed by punching is provided at the connection portion with the bottom wall and the outer groove wall.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and particularly to batteries and electronic devices.

Background Art

[0002] With the development of social economy, more and more electrical devices, such as new energy vehicles, communication base stations, and energy storage containers, are adopting batteries as energy storage and supply devices.

[0003] Currently, in some battery models, when performing the sealing process of the outer case by laser welding, due to the bosses formed by punching on the edge of the cover plate, there is a certain gap between its side wall and the outer case. As a result, the incident laser is reflected within the gap and reaches the electrode assembly inside the outer case, damaging the electrode assembly and easily causing problems in the product quality.

Summary of the Invention

Problems to be Solved by the Invention

[0004] In view of the above problems, the present invention provides a battery and an electronic device that can prevent laser irradiation on the electrode assembly, avoid damage to the electrode assembly, and ensure the product yield when sealingly welding the outer case of the battery.

Means for Solving the Problems

[0005] The present invention provides a battery comprising an outer case including an opening and a cover plate that closes the opening, wherein a portion of the cover plate adjacent to the edge protrudes toward the internal space of the outer case to form a boss, the boss includes a groove on one side away from the internal space of the outer case, the portion of the cover plate located radially outward of the boss constitutes a connecting edge, the boss is embedded in the opening, the connecting edge overlaps with the end of the outer case, and further, there is a welded mark formed between the connecting edge and the end of the outer case, the cross-sectional size of the welded mark gradually decreases from the radially outward to the radially inward of the cover plate, the cross-section is determined by the central axis of the cover plate and an arbitrary radial line, the inner wall of the groove includes a bottom wall and an outer groove wall surrounding the outer circumference of the bottom wall, and a punched groove is provided at the connection portion between the bottom wall and the outer groove wall.

[0006] In some embodiments, the outer groove wall includes a straight wall portion extending along the thickness direction of the cover plate, and in the radial direction of the cover plate, the outermost end of the punched groove does not extend beyond the straight wall portion.

[0007] In some embodiments, the punched groove has a groove cross-section cut along a reference plane, the reference plane is determined by the central axis of the cover plate and any radial line, and the groove cross-section is symmetrical in any portion along the radial direction of the cover plate with respect to the central axis.

[0008] In some embodiments, the punched groove has a groove cross-section cut along a reference plane, the reference plane is determined by the central axis and an arbitrary radial line of the cover plate, the groove cross-section is asymmetrical in any portion along the radial direction of the cover plate with respect to the central axis, and furthermore, the deepest part of the punched groove is located on one side closer to the outer groove wall than the center line L in the width direction of the groove cross-section of the punched groove.

[0009] In some embodiments, the height H1 of the boss on the cover plate is in the range of 0.8 mm ≤ H1 ≤ 5 mm; and / or, the depth H2 of the groove in the thickness direction of the cover plate is in the range of 0.1 mm ≤ H2 ≤ 4.5 mm; and / or, the depth H3 of the punched groove in the thickness direction of the cover plate is in the range of 0.05 mm ≤ H3 ≤ 0.4 mm; and / or, the outer surface of the boss includes a linear extension that is in close contact with the inner wall of the outer case, and the height H4 of the linear extension in the thickness direction of the cover plate is in the range of H4 ≥ 0.1 mm; and / or, in the radial direction of the cover plate, the distance between the width W1 of the punched groove and the width W2 of the groove satisfies 0.05 ≤ W1 / W2 ≤ 0.2; and / or, the connection portion between the outer surface and the bottom surface of the boss further has an outer chamfer, and the radius R1 of the outer chamfer is in the range of 0.1 mm ≤ R1 ≤ 1.2 mm.

[0010] In some embodiments, the battery further includes an electrode assembly provided within the outer casing and having a tab at one end facing the cover plate, wherein a welded area is provided in the portion of the bottom wall other than the punched groove, and the cover plate is electrically connected to the tab via the welded area.

[0011] In some embodiments, the battery is provided between the cover plate and the tab, and further includes a current collector plate welded to the welded area and the tab of the cover plate, respectively, with the boss in contact with it.

[0012] In some embodiments, along the radial direction of the cover plate, the minimum distance T between the punched groove and the welded area satisfies 0.2 mm ≤ T ≤ 1 mm.

[0013] In some embodiments, the hardness of the cover plate is 100 HV or higher.

[0014] A second aspect of the present invention provides an electronic device including the battery described in the first aspect of the present invention. [Effects of the Invention]

[0015] According to the battery of the present invention, a boss is provided on the edge of the cover plate, the boss is embedded in the opening of the outer case, the boss is provided with a connecting edge that is welded in close contact with the end face of the outer case along the radially outward direction, a groove is provided on one side of the boss away from the electrode assembly, and a punched groove is provided in the groove, formed by punching during the forming process of the punched groove, the metal at the connection between the bottom wall and the outer groove wall of the groove is pressed by the pressure generated by punching and flows toward the outer surface of the boss, so that the chamfered portion on one side of the boss facing the inner wall of the outer case becomes smaller, the straight extension portion of the outer surface of the boss becomes longer, the adhesion effect between the outer surface of the boss and the inner wall of the outer case becomes more favorable, and the boss can more favorably block the laser. In this way, when welding the gap between the connecting edge and the end face of the outer casing using a laser welding device, it is possible to prevent the laser from being reflected in the gap between the outer surface of the boss and the inner wall of the outer casing after the laser has entered the inside of the outer casing, thereby preventing the laser from irradiating the electrode assembly and damaging it. This improves the welding quality of the battery and ensures product yield. [Brief explanation of the drawing]

[0016] To more clearly illustrate embodiments of the present invention or technical solutions in the prior art, the drawings necessary for use in describing embodiments or the prior art are briefly introduced below. Clearly, the drawings described below are some embodiments of the present invention. For a general technician in this art, other drawings can be obtained based on these drawings without any creative work.

[0017] [Figure 1] This is a schematic diagram of the battery structure in several embodiments of the present invention. [Figure 2] This is a cross-sectional view along groove cross-section AA in Figure 1. [Figure 3] This is an enlarged view of the area B enclosed by the circle in Figure 2. [Figure 4]This is a schematic diagram of the flow of the cover plate material during the forming process of punched grooves in some embodiments of the present invention. [Figure 5] This is a schematic diagram of the flow of the cover plate material during the forming process of punched grooves in some other embodiments of the present invention. [Figure 6] This is a schematic diagram of a partial structure of a battery in several embodiments of the present invention. [Figure 7] This is a schematic diagram of the structure of an electrode assembly in several embodiments of the present invention. [Modes for carrying out the invention]

[0018] To make the objectives, features, and advantages of the embodiments of the present invention clearer and easier to understand, the technical solutions of the embodiments of the present invention are described below clearly and completely, together with the drawings of the embodiments of the present invention. Obviously, the embodiments described are not all embodiments of the present invention, but only a part of them. All other embodiments obtained by a person ordinary in the art without creative work based on the embodiments of the present invention are included within the scope of the protection of the present invention.

[0019] With the development of social economy, more and more electrical devices, such as new energy vehicles, communication base stations, and energy storage containers, are adopting batteries as energy storage and supply devices. Currently, in some battery models, a punching process is adopted to provide bosses at the edge of the cover plate, the bosses are embedded in the outer case, and then a laser welding method is adopted to perform a sealing process on the outer case. However, in the case of steel shell batteries or other batteries with high shell strength, the cover plate has high strength, so it is difficult to form during punching, and the chamfer part of the side wall used for fitting with the outer case on the boss formed by punching is likely to become large. When the chamfer part becomes large, the straight part on the side wall of the boss becomes short, and even the straight part disappears, resulting in a certain gap between the side wall of the boss and the outer case. Thus, when welding the fitting joint between the cover plate and the outer case, the incident laser is likely to be reflected in the gap and reach the electrode assembly inside the outer case, damaging the electrode assembly and easily causing problems with the product quality.

[0020] In view of this, the present embodiment provides a battery 100 that can be a primary battery or a secondary battery. A primary battery refers to a battery that cannot be recharged after discharge, and a secondary battery refers to a battery that can be reused by charging after discharge to reactivate the active substances. The battery can be a lithium-ion battery, a sodium-ion battery, a sodium-lithium-ion battery, a lithium metal battery, a sodium metal battery, a lithium-sulfur battery, a magnesium-ion battery, a nickel-cadmium battery, etc., but the embodiments of the present application do not limit thereto.

[0021] Combining FIGS. 1 to 2, specifically, the battery 100 of the present embodiment may include an outer case 1, a cover plate 2, and an electrode assembly 3. Here, an opening is provided at one end of the outer case 1, and the internal space of the outer case 1 functions as a housing cavity for the electrode assembly 3. Taking the case where the battery 100 is a cylindrical battery as an example, the outer case 1 may be cylindrical with an opening at the upper end or the bottom end, and the inside of the outer case 1 defines a cylindrical housing cavity. The cover plate 2 covers the opening of the outer case 1 and can close the opening.

[0022] Referring to FIG. 3, the electrode assembly 3 is provided in the internal space of the outer case 1, and a tab 31 is provided at one end of the electrode assembly 3 facing the cover plate 2, and the tab 31 is electrically connected to the cover plate 2. For example, the cover plate 2 may be a negative electrode cover plate, the tab 31 may be a negative electrode tab, and the negative electrode cover plate and the negative electrode tab may be directly welded to achieve electrical connection, or electrical connection may be achieved through an intermediate adapter, such as a current collector plate 4, between the negative electrode cover plate and the negative electrode tab. At this time, both the negative electrode cover plate 2 and the negative electrode tab are welded to the current collector plate 4.

[0023] Combining with FIG. 2, the outer case 1 further includes a side wall 11 and an upper wall 12. The side wall 11 is provided around the upper wall 12, and the upper wall 12 is located at one end facing the opening of the side wall 11. The battery 100 is further provided with a positive current collector plate 5 and an electrode 6. The electrode 6 penetrates the upper wall. A positive electrode tab 323 is provided at one end of the electrode assembly 3 facing the electrode 6. The positive current collector plate 5 is provided between the electrode 6 and the electrode assembly 3, and the positive current collector plate 5 is welded to the electrode 6 and the positive electrode tab 323 of the electrode assembly 3, respectively. At this time, the current collector plate 4 can function as the negative current collector plate of the battery 100, and the tab 31 at one end of the electrode assembly 3 facing the cover plate 2 functions as the negative electrode tab of the electrode assembly 3.

[0024] Optionally, referring to Figure 7, the electrode assembly 3 may include a positive electrode sheet 32, a negative electrode sheet 33, and a separator 34. Here, the positive electrode sheet 32 ​​includes a positive electrode fluid collector 321 and a positive electrode active coating layer 322 coated on the surface of the positive electrode fluid collector 321. The negative electrode sheet 33 includes a negative electrode fluid collector 331 and a negative electrode active coating layer 332 coated on the surface of the negative electrode fluid collector 331. Taking the case where the battery 100 is a cylindrical battery 100 as an example, the positive electrode sheet 32, separator 34, and negative electrode sheet 3 are stacked in order and wound together to form a wound electrode assembly 3.

[0025] Of course, in other possible embodiments, the battery 100 may be a prismatic shell battery. In this case, the positive electrode sheet 32, the separator 34, and the negative electrode sheet 33 may be stacked in order and wound together to form a wound electrode assembly 3. Alternatively, the positive electrode sheet 32, the separator 34, and the negative electrode sheet 33 may all have a multilayer structure, and the positive electrode sheet 32 ​​and the negative electrode sheet 33 may be stacked alternately, with the positive electrode sheet 32 ​​and the negative electrode sheet 33 separated by the separator 34 to form a stacked electrode assembly 3.

[0026] Referring to Figure 3, the portion of the cover plate 2 adjacent to the edge protrudes toward the internal space of the outer case 1, forming a boss 21, and one side of the boss 21 away from the internal space of the outer case 1 includes a groove 22. For example, the boss 21 may be formed by a punching process on the edge of the cover plate 2. During punching, the boss 21 is formed on the inner surface of the cover plate 2 (i.e., the surface on one side facing the housing cavity), and the groove 22 is formed on the one side of the boss 21 away from the housing cavity (i.e., the outer surface of the cover plate 2). Furthermore, a portion of the cover plate 2 radially outward of the boss 21 is formed as a connecting edge 24. When the boss 21 is embedded in the opening, the connecting edge 24 overlaps with the end of the outer case 1, and furthermore, the connecting edge 24 is welded to the end face of the outer case 1. For example, the welding method may be laser welding, ultrasonic welding, etc. At this time, a weld mark 25 is formed between the connecting edge 24 and the end face of the outer case 1. The cross-sectional size of the weld marks 25 gradually decreases as you move from the radially outer side to the radially inner side of the cover plate 2. Here, the cross-section may be determined by the central axis of the cover plate 2 and any radial line, such as the AA cross-section shown in Figures 1 and 2.

[0027] In conjunction with Figure 3, it should be noted that in this embodiment, the laser welding apparatus can perform laser seam welding from the side of the outer case 1 along the radial direction of the cover plate 2 toward the joint between the connecting edge 24 and the end face of the outer case 1 (as shown in the direction of the arrow in the welding mark 25 in Figure 3), thereby forming a welding mark 25. Furthermore, during the welding process, the laser welding apparatus may be held and fixed in position, and welding may be performed by rotating only the battery 100. When welding the connecting edge 24 and the outer case 1 by laser welding, the cross-sectional size, such as the width of the cross-section of the welding mark 25, gradually decreases as it moves away from the welding apparatus along the laser transmission direction. In this embodiment, a welding mark 25 is formed between the connecting edge 24 and the end face of the outer case 1, and the cross-sectional size of the welding mark 25 gradually decreases as it moves from the radially outer side to the radially inner side of the cover plate 2. By welding the fitting joint between the connecting edge 24 and the outer case 1 by laser seam welding, the gap can be more preferably closed, and furthermore, the process becomes more mature and reliable, ensuring welding quality.

[0028] Referring to Figure 3, the inner wall of the recessed groove 22 includes a bottom wall 222 and an outer groove wall 223 surrounding the outer circumference of the bottom wall 222. Here, a punched groove 23 is provided at the connection point between the bottom wall 222 and the outer groove wall 223, that is, the punched groove 23 is formed on the inner chamfered portion 221 of the connection point between the bottom wall 222 and the outer groove wall 223. Optionally, the punched groove 23 and the recessed groove 22 may be formed simultaneously in the same punching process.

[0029] It should be explained that when the punched groove 23 is not provided, and the cover plate 2 is punched to form the boss 21, the outer chamfer portion 211 at the intersection of the outer surface 210 (facing the outer groove wall 223 of the groove 22) and the bottom surface (facing the bottom wall 222 of the groove 22) of the boss 21 is relatively large, and the straight extension portion 212 of the outer surface of the boss 21 (this straight extension portion 212 is the part where the outer surface 210 of the boss 21 contacts the outer case 1, and this portion extends along the axial direction of the cover plate 2) is relatively short, so there is a certain gap between the outer surface 210 of the boss 21 and the inner wall of the outer case 1. Thus, when the connecting edge 24 and the end face of the outer case 1 are welded to form a weld mark 25, the laser irradiated from the laser welding device toward the gap between the connecting edge 24 and the end face of the outer case 1 enters the housing cavity, is easily reflected by the gap between the outer surface 210 of the boss 21 and the inner wall of the outer case 1, and ultimately reflects off the electrode assembly 3, potentially causing damage to the electrode assembly 3. In this embodiment, by providing a punched groove 23 at the connection portion between the bottom wall 222 and the outer groove wall 223 of the recessed groove 22, during the forming process of the punched groove 23, the punching device presses against the inner wall of the recessed groove 22, causing the material at the connection portion between the bottom wall 222 and the outer groove wall 223 to flow and deform toward one side of the outer case 1, the outer chamfer portion 211 of the boss 21 to become smaller, the straight extension portion 212 of the outer surface 210 of the boss 21 to become longer, and the contact effect between the outer surface 210 of the boss 21 and the inner wall of the outer case 1 to become more favorable. In this way, even if the laser enters the inside of the outer casing 1 through the gap between the connecting edge 24 and the end face of the outer casing 1, the boss 21 can block the laser, preventing the laser from being reflected off the electrode assembly 3 and damaging the electrode assembly 3.

[0030] According to the battery 100 in the embodiment of the present invention, a boss 21 is provided on the edge of the cover plate 2, the boss 21 is embedded in the opening of the outer case 1, and the boss 21 is provided with a connecting edge 24 that is welded in close contact with the end face of the outer case 1 along the radially outward direction, and a groove 22 is provided on one side of the boss 21 away from the electrode assembly 3, and a punched groove 23 formed by punching is provided at the connection between the bottom wall 222 and the outer groove wall 223 of the groove 22. In the process of forming the punched groove 23, the pressure generated by the punching device causes the metal at the connection between the bottom wall 222 and the outer groove wall 223 of the recessed groove 22 to flow toward the outer surface of the boss. As a result, the chamfered portion on one side of the boss 21 facing the inner wall of the outer case 1 becomes smaller, the straight extension portion 212 of the outer surface 210 of the boss 21 becomes longer, the adhesion effect between the outer surface 210 of the boss 21 and the inner wall of the outer case 1 becomes more favorable, and the boss 21 can more favorably block the laser. In this way, when welding the gap between the connecting edge 24 and the end face of the outer case 1 using a laser welding device, it is possible to prevent the laser from being reflected within the gap between the outer surface 210 of the boss 21 and the inner wall of the outer case 1 after the laser has entered the inside of the outer case 1, and to prevent the laser from irradiating the electrode assembly 3 and damaging the electrode assembly 3, thereby improving the welding quality of the battery 100 and ensuring product yield.

[0031] In some embodiments, referring to Figures 3 and 4, the opening direction of the punched groove 23 is in the direction away from the internal space of the outer case 1 along the axial direction of the cover plate 2. The outer groove wall 223 of the recessed groove 22 includes a straight wall portion 2231 that extends along the thickness direction of the cover plate 2, and the straight wall portion 2231 and the inside and outside of the straight extension portion 212 of the outer surface 210 of the boss 21 are parallel to each other. In the radial direction of the cover plate 2, the outermost end of the punched groove 23 does not extend beyond this straight wall portion 2231. In this way, by simply providing the punching machine with a protruding structure that fits with the punched groove 23, the recessed groove 22 and the punched groove 23 can be formed simultaneously using the punching machine. In other words, when punching along the thickness direction of the cover plate 2, the protruding structure in the punching machine and the outer groove wall 223 of the recessed groove 22 do not interfere with each other in the thickness direction of the cover plate 2, and after the processing of the punched groove 23 is completed, the punching machine can be more easily retracted from the recessed groove 22.

[0032] Furthermore, since the opening direction of the recessed groove 22 and the opening direction of the punched groove 23 are almost identical, the punching device can form the punched groove 23 and the recessed groove 22 by performing punching along the thickness direction of the cover plate 2 only once, making the manufacturing process of the cover plate 2 simpler and more efficient. Of course, it is also possible to perform two punching processes, first punching out the recessed groove 22 and then punching out the punched groove 23.

[0033] The punched groove 23 has a groove cross-section cut along a reference plane (for example, the AA cross-section shown in Figures 1 and 2), and the reference plane may be determined by the central axis of the cover plate 2 and any radial line. That is, the reference plane passes through the central axis and radial line of the cover plate 2. Since the punched groove 23 is formed in an annular shape surrounding the cover plate 2, the groove cross-section of the punched groove 23 on the reference plane includes two parts, each of which is located on either side of the central axis of the cover plate 2.

[0034] Referring to Figure 3, in this embodiment, the groove cross-section has a symmetrical structure on any one side along the radial direction of the cover plate 2 relative to the central axis. For example, the groove cross-section portion on any one side along the radial direction of the central axis of the cover plate 2 of the punched groove 23 may be formed in a V-shape, U-shape, or other symmetrical structure. In this way, during the punching process, the cover plate material corresponding to the punched groove 23 flows uniformly toward the outer circumference, the outer chamfer portion of the boss 21 becomes smaller, and the length of the linear extension portion 212 on the outer surface 210 of the boss 21 becomes longer.

[0035] In some other embodiments, referring to Figure 4, the groove cross-section may be asymmetric in any portion along the radial direction of the cover plate 2 relative to the central axis, and furthermore, the deepest part of the punched groove 23 is located on one side closer to the outer groove wall 223 of the centerline in the width direction of the groove cross-section. Here, the width direction of the punched groove 23 is parallel to the radial direction of the cover plate 2. In this way, compared with solutions in which the punched groove 23 is symmetric, in this embodiment, when processing the punched groove 23, the cover plate 2 material between the inner chamfer 221 and the outer chamfer 211 can mainly flow deform toward one side of the outer case 1, reducing the flow deformation of the material in other directions, efficiently reducing the outer chamfer 211 of the boss 21, increasing the length of the linear extension 212 on the outer surface 210 of the boss 21, improving the forming efficiency of the punched groove 23, and ensuring tight fit between the boss 21 and the outer case 1.

[0036] In some embodiments, when combined with Figure 6, the range of height H1 at the boss 21 of the cover plate 2 is 0.8 mm ≤ H1 ≤ 5 mm. Here, the height H1 at the boss 21 of the cover plate 2 may be the sum of the height of the boss 21 and the thickness of the non-boss portion of the cover plate 2. For example, the value of height H1 at the boss 21 of the cover plate 2 may be 0.8 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3.5 mm, 4 mm, 4.5 mm, or 5 mm. Of course, the present invention is not limited thereto, and the height H1 at the boss 21 of the cover plate 2 can be reasonably selected within the above range as needed. In this way, on the one hand, if the height of the boss 21 is excessively small, for example less than 0.8 mm, it is possible to prevent the boss 21 from fitting too deeply into the outer case 1, which would prevent the boss 21 from effectively blocking the laser and the cover plate 2 from forming a stable fit with the outer case 1. On the other hand, if the height of the boss 21 is excessively large, for example, more than 5 mm, it is possible to prevent the boss 21 from excessively occupying the internal space of the outer case 1, which would be detrimental to improving the utilization rate and energy density of the internal space of the battery 100.

[0037] In some embodiments, when combined with Figure 6, the range of depth H2 of the groove 22 in the thickness direction of the cover plate 2 is 0.1 mm ≤ H2 ≤ 4.5 mm. For example, the value of depth H2 of the groove 22 in the thickness direction of the cover plate 2 may be 0.1 mm, 0.2 mm, 0.5 mm, 0.8 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, or 4.5 mm. Of course, the present invention is not limited thereto, and the depth H2 of the groove 22 in the thickness direction of the cover plate 2 can be reasonably selected within the above range as needed. In this way, on the one hand, if the depth of the groove 22 is excessively small, for example less than 0.1 mm, the height of the boss 21 will be excessively small, preventing the boss 21 from effectively blocking the laser and forming a stable fit with the outer case 1. On the other hand, if the depth of the groove 22 is excessively large, for example, more than 4.5 mm, the boss 21 will not excessively occupy the internal space of the outer case 1, which would be detrimental to improving the utilization rate and energy density of the internal space of the battery 100. It can be seen that the depth of the groove 22 is always smaller than the thickness of the boss 21 on the cover plate 2.

[0038] In some embodiments, when combined with Figure 6, the range of depth H3 in the thickness direction of the punched groove 23 in the cover plate 2 is 0.05 mm ≤ H3 ≤ 0.4 mm. For example, the depth H3 in the thickness direction of the punched groove 23 in the cover plate 2 may be 0.05 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, or 0.4 mm. Of course, the present invention is not limited thereto, and the depth H3 in the thickness direction of the punched groove 23 in the cover plate 2 can be reasonably selected within the above range as needed. In this way, on the one hand, if the depth of the punched groove 23 is excessively small, for example less than 0.05 mm, the pressure on the cover plate 2 material between the inner chamfer 221 and the outer chamfer 211 during the forming process of the punched groove 23 will be excessively small, the outer chamfer 211 of the boss 21 will not be effectively reduced, the outer surface 210 of the boss 21 will not be able to form an effective fit with the inner wall of the outer case 1, and the laser shielding effect of the boss 21 will not be limited. On the other hand, if the depth of the punched groove 23 is excessively large, for example more than 0.4 mm, the bottom wall 222 of the recessed groove 22 will be pushed out, the cover plate 2 will be damaged and will have to be discarded. It can be seen that the depth of the punched groove 23 is always smaller than the wall thickness of the boss 21.

[0039] In some embodiments, when combined with Figure 6, the outer surface 210 of the boss 21 includes a linear extension 212. For example, the portion of the outer surface 210 of the boss 21 other than the outer chamfer is formed as the linear extension 212. The height H4 of the linear extension 212 in the thickness direction of the cover plate 2 is in the range of 0.1 mm ≤ H4 ≤ 2 mm. For example, the height H4 of the linear extension 212 in the thickness direction of the cover plate 2 may be 0.1 mm, 0.2 mm, 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, or 2 mm. Of course, the present invention is not limited thereto, and the height H4 of the linear extension 212 in the thickness direction of the cover plate 2 can be reasonably selected within the above range as needed. In this way, on the one hand, if the height of the linear extension portion 212 is excessively small, for example less than 0.1 mm, it is possible to prevent the depth to which the boss 21 fits into the outer case 1 from becoming too small, which would be detrimental to favorably blocking the laser at the weld mark 25 between the connecting edge 24 and the end face of the outer case 1. On the other hand, if the height of the linear extension portion 212 is excessively large, for example more than 2 mm, it is possible to prevent the boss 21 from excessively occupying the internal space of the outer case 1, which would be detrimental to improving the utilization rate and energy density of the internal space of the battery 100.

[0040] In some embodiments, when Figure 6 is combined, the ratio between the width W1 of the punched groove 23 and the width W2 of the recessed groove 22 along the radial direction of the cover plate 2 satisfies 0.1 ≤ W1 / W2 ≤ 1. For example, the ratio of W1 to W2 may be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1. When the ratio is 1, the radial width W1 of the punched groove 23 in the cover plate 2 is the same as the width W2 of the recessed groove 22. Of course, the present invention is not limited thereto, and the ratio of W1 to W2 can be reasonably selected within the above range as needed. In this way, the processing device can smoothly extend into the groove 22 to process the punched groove 23, and when processing the punched groove 23, the cover plate material in the punched groove 23 is preferably flowed toward one side of the outer groove wall 223 of the groove 22, thereby reducing the outer chamfer portion 211 of the boss 21 and ensuring that the length of the straight extension portion 212 on the outer surface 210 of the boss 21 is increased. In this way, when laser seam welding is performed between the connecting edge 24 of the cover plate 2 and the end of the outer case 1, the boss 21 can more preferably block the laser.

[0041] In some embodiments, when combined with Figure 6, an outer chamfer 211 is further provided at the connection between the outer surface 210 and the bottom surface 213 of the boss 21. The outer chamfer 211 faces the inner chamfer 221, and the radius R1 of the outer chamfer 211 is in the range of 0.1 mm ≤ R1 ≤ 1.2 mm. For example, the radius R1 of the outer chamfer 211 may be 0.1 mm, 1.2 mm, 0.4 mm, 0.5 mm, 0.8 mm, 1 mm, or 1.2 mm. Of course, the present invention is not limited thereto, and the radius R1 of the outer chamfer 211 can be reasonably selected within the above range as needed. In other words, after processing the punched groove 23, if the radius of the outer chamfer 211 of the boss 21 facing one side of the outer case 1 is within the above range, it is possible to ensure that the outer surface 210 of the boss 21 preferably adheres closely to the inner wall of the outer case 1 and blocks the laser.

[0042] In some embodiments, a welded area 224 is provided in the portion of the bottom wall 222 of the groove 22 other than the punched groove 23. The welded area 224 is a weld mark formed by welding the cover plate 2 to the internal assembly of the battery. The cover plate 2 may be electrically connected to the tab 31 via the welded area 224. For example, the welded area 224 and the tab 31 may be directly welded to achieve the electrical connection between the cover plate 2 and the tab 31. Alternatively, the welded area 224 may be electrically connected to the tab 31 via an intermediate adapter such as a current collector plate 4. In this way, there are various methods for connecting the cover plate 2 and the tab 31, and they can be reasonably selected according to the actual requirements.

[0043] In one specific example, the battery 100 may further include a current collector plate 4. The current collector plate 4 is provided between the cover plate 2 and the tab 31, and is welded to the welding area 224 and the tab 31 of the cover plate 2, respectively. In other words, the cover plate 2 and the tab 31 achieve a temporary connection via the current collector plate 4, and the current collector plate 4 functions as an intermediate adapter between the cover plate 2 and the tab 31. In this case, the boss 21 can contact the current collector plate 4. Thus, on the one hand, by pressing the current collector plate 4 with the boss 21, the positional fixation of the current collector plate 4 and the electrode assembly 3 within the outer casing 1 can be ensured. On the other hand, since the boss 21 is part of the structure of the cover plate 2 and is a metal part, heat can be conducted using the boss 21 even if the boss 21 is not electrically connected to the current collector plate 4 (for example, the central area of ​​the current collector plate 4 is welded to the cover plate 2, and the boss 21 and the welding area 224 are radially separated). In some possible embodiments, the boss 21 can be directly welded to the heat collector plate 4 to achieve conduction between the cover plate 2 and the heat collector plate 4. In this case, the boss 2 can provide both electrical connection and heat conduction.

[0044] When welding the bottom wall 222 of the groove 22 to the current collector plate 4 by laser penetration welding, the laser irradiation direction is the same as the thickness direction of the cover plate 2, and the laser energy density when the laser is irradiated onto the surface of the object to be welded is related to the distance from the laser focal point to the welding surface. Since the inner wall surface of the punched groove 23 is not a plane perpendicular to the laser, when welding is performed within the punched groove 23, the distance from the laser focal point differs depending on the welding position, and the laser energy density obtained at different points will differ. As a result, the welding depth at each point will be uneven, and it may not be possible to ensure an effective connection between the punched groove 23 and the current collector plate 4. In this embodiment, the welding area 224 is provided in the straight portion of the bottom wall 222, and since the welding area 224 avoids the punched groove 23, the laser energy is more preferably concentrated, passes through the cover plate 2 to the current collector plate 4, and ensures that an effective and reliable connection is formed between the boss 21 and the current collector plate 4.

[0045] In some embodiments, when Figure 6 is combined, the range of the radial width W2 of the cover plate 2 of the groove 22 is 2 mm ≤ W2 ≤ 15 mm. For example, the radial width W2 of the cover plate 2 of the groove 22 may be 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, or 15 mm. Of course, the present invention is not limited thereto, and the radial width W2 of the cover plate 2 of the groove 22 can be reasonably selected within the above range as needed. In this way, on the one hand, if the width of the groove 22 is excessively small, for example less than 2 mm, it is possible to prevent the welding equipment from entering the groove 22 to perform welding work, and also to prevent the processing equipment from entering the groove 22 to process the punched groove 23. On the other hand, if the width of the groove 22 is excessively large, for example, more than 15 mm, it is possible to prevent the surface area of ​​the cover plate 2 that makes thermal contact with the module cooling system from becoming too small, which would be detrimental to the external heat dissipation of the battery 100.

[0046] In some embodiments, combining Figures 3 and 6, the range of the radial width W3 of the cover plate 2 in the welding area 224 is 0.5 mm ≤ W3 ≤ 13 mm. For example, the radial width W3 of the cover plate 2 in the welding area 224 may be 0.5 mm, 1 mm, 2 mm, 4 mm, 6 mm, 8 mm, 10 mm, 12 mm, or 13 mm. Of course, the present invention is not limited thereto, and the radial width W3 of the cover plate 2 in the welding area 224 can be reasonably selected within the above range as needed. In this way, on the one hand, if the width of the welding area 224 is excessively small, for example less than 0.5 mm, it is possible to prevent the welding area between the boss 21 and the current collector plate 4 from becoming too small, resulting in high resistance at the weld site and poor current capacity. On the other hand, if the width of the welding area 224 is excessively large, for example more than 13 mm, it is possible to prevent the welding area from becoming excessively large, making it difficult to ensure welding quality.

[0047] In some embodiments, referring to Figure 3, the minimum distance T between the punched groove 23 and the welding area 224 along the radial direction of the cover plate 2 is 0.2 mm ≤ T ≤ 1 mm. For example, the minimum distance T between the punched groove 23 and the welding area 224 may be 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, or 1 mm. Of course, the present invention is not limited thereto, and the minimum distance T between the punched groove 23 and the welding area 224 can be reasonably selected within the above range as needed. In this way, it is possible to prevent the phenomenon in which welding heat is transmitted into the punched groove 23 due to a gap that is too narrow, causing a welding explosion point. At the same time, it is possible to prevent mutual interference between the punched groove 23 and the welding area 224, which also helps to release stress during the welding process.

[0048] In some embodiments, the hardness of the cover plate 2 is 100 HV or higher. In this way, it is possible to ensure that the cover plate 2 has sufficient strength and good pressure resistance. For example, the cover plate 2 may be a steel structural member such as a commonly used cold-rolled carbon steel sheet or strip (SPCC).

[0049] The following describes an electronic device according to a second embodiment of the present invention.

[0050] The electronic devices of this embodiment may include vehicles, mobile phones, portable devices, laptop computers, ships, spacecraft, electric toys, and power tools. Vehicles may include fuel-powered vehicles, gas vehicles, or new energy vehicles. New energy vehicles may include pure electric vehicles, hybrid vehicles, and long-distance vehicles. Spacecraft may include airplanes, rockets, space shuttles, and spaceships. Electric toys include stationary or mobile electric toys such as game consoles, electric vehicle toys, electric boat toys, and electric airplane toys. Power tools include electric tools for metal cutting, grinding, assembly, and railway power tools, and include, for example, electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers. Electronic devices may also include battery modules and battery packs. The embodiments of the present invention are not particularly limited to the electronic devices described above.

[0051] The electronic device may include the main body of the device and the battery 100 of the embodiment described above. The main body of the device may include a battery compartment, and the battery 100 is provided in the battery compartment and electrically connected to the main body of the device. For example, a power interface may be provided in the battery compartment, and the battery 100 may be connected to the power interface.

[0052] In the embodiment of the present invention, by providing the battery 100 of the embodiment, the welding quality of the battery 100 is further improved, which is beneficial for improving the user experience.

[0053] Embodiments referred to herein by terms such as “one embodiment,” “embodiment,” “exemplary embodiment,” and “some embodiments” may include certain features, structures, or characteristics, but it should be noted that not all embodiments will include such features, structures, or characteristics. Furthermore, such terms do not necessarily refer to the same embodiment. Also, if certain features, structures, or characteristics are described in conjunction with an embodiment, whether explicitly described or not, implementing such features, structures, or characteristics in conjunction with other embodiments is within the knowledge of those skilled in the art.

[0054] In general, terms should be understood, at least in part, by their usage in the context in which they are used. For example, at least in part, depending on the context, the term “one or more” as used herein may be used in a singular sense to describe any feature, structure, or characteristic, or in a plural sense to describe a combination of features, structures, or characteristics. Similarly, terms such as “one” and “the said” may be interpreted as singular or plural, depending on the context.

[0055] Furthermore, it should be readily understood that "on top of...", "above...", and "on top of..." in this disclosure should be interpreted in the broadest sense, and that "on top of..." not only means "directly on top of something" but also includes the meaning of "on top of something" with an intervening feature or layer, and that "above..." or "on top of..." can include not only the meaning of "above..." or "on top of something" but also the meaning of "above..." or "on top of..." without an intervening feature or layer (i.e., directly on top of something).

[0056] Furthermore, for the sake of clarity, spatially relative terms such as "down," "below," "directly below," "up," and "up" may be used to describe the relationship between one element or feature and another, as shown in the drawings. These spatially relative terms are intended to encompass various orientations of the device in use or operation, in addition to the orientations depicted in the drawings. The device may also have other orientations (90-degree rotation or other orientations), and the spatially relative terms used herein shall be interpreted accordingly.

[0057] Finally, it should be noted that the embodiments described above are used solely to illustrate the technical solutions of the present application and are not intended to limit them. Although the present invention has been described in detail with reference to the embodiments described above, those skilled in the art should understand that the technical solutions described in the embodiments above can be modified or some or all of their technical features can be replaced with equivalents. Such modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application. [Industrial applicability]

[0058] The battery and electronic device of the present invention can be applied to the battery technology field. [Explanation of symbols]

[0059] 1: Outer case 11: Side wall 12: Upper wall 2: Cover plate 21: Boss 210:Outer surface 211: Outer chamfered section 212: Linear extension part 213: Bottom 22: Groove 221: Inner chamfered section 222: Bottom wall 223: Exterior wall 2231: Straight wall section 224: Welding Area 23: Punched groove 24: Connecting Edge 25: Weld marks 3: Electrode Assembly 31: Tab 32: Positive electrode sheet 321: Positive electrode fluid collector 322: Cathode Activated Coating Layer 323: Positive Tab 33: Negative electrode sheet 331: Negative electrode fluid collector 332: Negative electrode activated coating layer 34: Separator; 4: Current collector plate 5: Positive electrode current collector plate 6: Extreme 100:Battery H1, H4: Height H2, H3: Depth L: Center line R1: Radius T: Minimum spacing W1, W2, W3: Width

Claims

1. The outer case including the opening, The cover plate includes a cover plate that closes the opening, the portion of the cover plate adjacent to the edge protrudes toward the internal space of the outer case to form a boss, the side of the boss away from the internal space of the outer case includes a groove, and the portion of the cover plate located radially outward of the boss constitutes a connecting edge. The boss is embedded in the opening, the connecting edge overlaps with the end of the outer casing, and there is a welded mark between the connecting edge and the end of the outer casing, the cross-sectional size of the welded mark gradually decreases from the radially outer to the radially inner side of the cover plate, and the cross-section is determined by the central axis of the cover plate and an arbitrary radial line. The inner wall of the groove includes a bottom wall and an outer groove wall surrounding the outer periphery of the bottom wall, and a punched groove is provided at the connection point between the bottom wall and the outer groove wall. The outer surface of the boss includes a straight extension that contacts the inner wall of the outer casing. A battery characterized by the following features.

2. The outer groove wall includes a straight wall portion that extends along the thickness direction of the cover plate, In the radial direction of the cover plate, the outermost end of the punched groove does not extend beyond the straight wall portion. The battery according to claim 1, characterized in that...

3. The punched groove has a groove cross-section cut along a reference plane, and the reference plane is determined by the central axis of the cover plate and an arbitrary radial line. The groove cross-section has a symmetrical structure in any portion along the radial direction of the cover plate with respect to the central axis. The battery according to claim 2, characterized in that it is a battery.

4. The punched groove has a groove cross-section cut along a reference plane, and the reference plane is determined by the central axis of the cover plate and an arbitrary radial line. The groove cross-section has an asymmetric structure in any portion along the radial direction of the cover plate with respect to the central axis. Furthermore, the deepest part of the punched groove is located on one side closer to the outer groove wall than the center line L in the width direction of the groove cross-section of the punched groove. The battery according to claim 2, characterized in that it is a battery.

5. The height H1 of the boss on the cover plate is in the range of 0.8 mm ≤ H1 ≤ 5 mm; and / or, The depth H2 of the groove in the thickness direction of the cover plate is in the range of 0.1 mm ≤ H2 ≤ 4.5 mm; and / or, The range of depth H3 of the punched groove in the thickness direction of the cover plate is 0.05 mm ≤ H3 ≤ 0.4 mm; and / or, The range of height H4 in the thickness direction of the cover plate of the linear extension is H4 ≥ 0.1 mm; and / or, In the radial direction of the cover plate, the distance between the width W1 of the punched groove and the width W2 of the recessed groove satisfies 0.05 ≤ W1 / W2 ≤ 0.2; and / or, The connection portion between the outer surface and the bottom surface of the boss further has an outer chamfer, and the radius R1 of the outer chamfer is in the range of 0.1 mm ≤ R1 ≤ 1.2 mm. The battery according to claim 1, characterized in that...

6. An electrode assembly provided inside the outer casing, with a tab at one end facing the cover plate, It further includes, A welding area is provided in the portion of the bottom wall other than the punched groove, and the cover plate is electrically connected to the tab via the welding area. The battery according to claim 1, characterized in that...

7. A current collector plate is provided between the cover plate and the tab, and is welded to the welding area and the tab of the cover plate, respectively, and the boss abuts against it, The battery according to claim 6, further comprising

8. Along the radial direction of the cover plate, the minimum distance T between the punched groove and the welding area satisfies 0.2 mm ≤ T ≤ 1 mm. The battery according to claim 6, characterized in that it is a battery.

9. The hardness of the cover plate is 100 HV or higher. The battery according to claim 1, characterized in that...

10. An electronic device characterized by including a battery according to any one of claims 1 to 9.

Images