Welded body, battery case, battery and electric equipment

Abstract

The invention provides a welding body, a battery shell, a battery and electric equipment, the welding body comprises a first welding piece and a second welding piece, a first welding track is formed between the first welding piece and the second welding piece, the first welding track comprises a plurality of welding sections, each welding section comprises a first welding spot and a second welding spot, and the first welding spot and the second welding spot are welded together. The first welding spots cover at least part of the second welding spots, and at least part of adjacent first welding spots are not overlapped with each other. According to the welding body, the situation that the welding body deforms due to welding heat concentration can be avoided, and the welding yield of the welding body is increased.

Description

Technical Field

[0001] The present application relates to the field of welding technology, and in particular to a welding body, a battery shell, a battery and an electrical device. Background Art

[0002] With the development of science and technology, more and more electrical equipment uses batteries as energy storage and supply devices, such as new energy vehicles, communication base stations, energy storage containers, etc.

[0003] Currently, batteries come in various types, including prismatic and cylindrical. The battery case, a crucial component that houses the battery cell and electrolyte, significantly impacts battery performance. However, existing battery cases often suffer from a problem with heat generation during welding, leading to deformation. Summary of the Invention

[0004] In view of the above problems, the present application provides a welding body, a battery shell, a battery and an electrical device, which can prevent the first welding part and the second welding part welded to each other from being deformed due to concentrated welding heat, thereby improving the welding yield.

[0005] The present application provides a welding body, including: a first welding part and a second welding part, a first welding track is formed between the first welding part and the second welding part, the first welding track includes a plurality of welding segments, each of the welding segments includes a first welding point and a second welding point, the first welding point covers at least a portion of the second welding point, and at least some adjacent first welding points do not overlap with each other.

[0006] In some embodiments, any two adjacent first welding spots do not overlap with each other, and the minimum distance between any two adjacent first welding spots is not less than 0.05 mm.

[0007] In some embodiments, two adjacent non-overlapping first welding spots are connected via at least one second welding spot.

[0008] In some embodiments, there are multiple second welding spots between two adjacent non-overlapping first welding spots, and two adjacent second welding spots between two adjacent non-overlapping first welding spots at least partially overlap.

[0009] In some embodiments, the first solder joint covers at least a portion of the adjacent second solder joint.

[0010] In some embodiments, the first welding trajectory includes at least one straight trajectory extending in a straight line, and the straight trajectory includes a plurality of the welding segments.

[0011] In some embodiments, the first welding track includes a plurality of the linear tracks, wherein the straight lines on which any two adjacent linear tracks lie are perpendicular to each other.

[0012] In some embodiments, a second welding track is formed between the first welding part and the second welding part, and the second welding track includes at least one arc-shaped track extending in an arc shape. The arc-shaped track includes multiple third welding points, and two adjacent third welding points at least partially overlap.

[0013] In some embodiments, the first welding track includes a plurality of the linear tracks, wherein the straight lines on which any two adjacent linear tracks are located are perpendicular to each other, and the arc track is located at a corner position defined by the two adjacent linear tracks.

[0014] In some embodiments, the overlap rate between any mutually overlapping third welding points on the second welding track is a, and the value range of a is: 40%≤a≤80%.

[0015] In some embodiments, two adjacent non-overlapping first welds are connected by at least one second weld, the first weld covers at least part of the adjacent second weld, the maximum overlap rate between the first weld and the adjacent second weld is b, and a is not equal to b.

[0016] In some embodiments, a and b satisfy: a>b.

[0017] In some embodiments, the value range of b is: 35%≤b≤70%.

[0018] In some embodiments, the arc-shaped trajectory is an arc, and the radius R of the arc-shaped trajectory has a value range of: 0.5 mm ≤ R ≤ 2 mm.

[0019] In some embodiments, the second welding track is connected to the first welding track.

[0020] In some embodiments, the third welding spot of the second welding track and the first welding spot or the second welding spot of the first welding track partially overlap at a connection point.

[0021] In some embodiments, an overlap ratio c of the second welding spot and the third welding spot or the first welding spot and the third welding spot at the connection between the second welding track and the first welding track is in the range of 40%≤c≤70%.

[0022] In some embodiments, at the overlap of the second welding trajectory and the first welding trajectory, the first welding trajectory is located on a side of the second welding trajectory close to the first welding part, or the second welding trajectory is located on a side of the first welding trajectory close to the first welding part.

[0023] In some embodiments, the ratio of the area of ​​the first weld point to the area of ​​the first reference circle is 0.5-1, wherein the first reference circle is a circle determined based on the outer contour of the orthographic projection of the first weld point in the thickness direction of the first weld; and / or, the ratio of the area of ​​the second weld point to the area of ​​the second reference circle is 0.5-1, wherein the second reference circle is a circle determined based on the outer contour of the orthographic projection of the second weld point in the thickness direction of the first weld; and / or, the ratio of the area of ​​the third weld point to the area of ​​the third reference circle is 0.5-1, wherein the third reference circle is a circle determined based on the outer contour of the orthographic projection of the third weld point in the thickness direction of the first weld.

[0024] In some embodiments, the diameter W3 of the third reference circle determined by the outer contour of the orthographic projection of the third welding point in the thickness direction of the first welding part has a value range of: 0.1 mm ≤ W3 ≤ 0.3 mm;

[0025] In some embodiments, the thickness W1 of the shell body has a value range of: 0.1mm≤W1≤0.3mm; and / or, the thickness W2 of the cover plate has a value range of: 0.03mm≤W2≤0.1mm; and / or, the diameter W4 of the first reference circle determined by the outer contour of the orthographic projection of the first weld in the thickness direction of the first weld is in a value range of: 0.1mm≤W4≤0.3mm; and / or, the diameter W5 of the second reference circle determined by the outer contour of the orthographic projection of the second weld in the thickness direction of the first weld is in a value range of: 0.1mm≤W5≤0.3mm.

[0026] In some embodiments, the distance between any two adjacent first welding points is equal.

[0027] In some embodiments, the first welding track includes a first welding layer and a second welding layer, the first welding layer includes a plurality of the first welding spots of the welding segments, the second welding layer includes a plurality of the second welding spots of the welding segments, and the first welding layer covers at least a portion of the second welding layer.

[0028] The present application also provides a battery shell, which constitutes the above-mentioned welded body, and the battery shell includes: a shell body and a cover plate, at least one end of the shell body has an opening, the cover plate is sealed at the opening, and together with the shell body defines a accommodating cavity, wherein the cover plate constitutes the first welded part of the welded body, and the shell body constitutes the second welded part of the welded body.

[0029] In some embodiments, the shell body is formed with the openings at both opposite ends, there are two cover plates, and the two cover plates respectively cover the openings at both ends of the shell body, and the shell body is welded to each cover plate to form the first welding track and the second welding track.

[0030] The present application also provides a battery, comprising a battery cell and any of the above-mentioned battery shells, wherein the battery cell is located in a receiving cavity of the battery shell.

[0031] The present application also provides an electrical device comprising the above-mentioned battery.

[0032] According to the electrical equipment of the present application, by providing the above-mentioned battery, the electrical performance can be improved due to the higher welding quality of the battery shell, thereby better supplying power to the electrical equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0034] Figure 1 A schematic structural diagram of a battery according to an embodiment of the present application;

[0035] Figure 2 An exploded view of a battery according to an embodiment of the present application;

[0036] Figure 3 Schematic diagram of the welding position of the cover plate and the shell body in some embodiments of the present application;

[0037] Figure 4 for Figure 3 Schematic diagram of welding marks formed by corresponding welding methods;

[0038] Figure 5 for Figure 4 A schematic structural diagram of the second welding track in FIG;

[0039] Figure 6 for Figure 4 A schematic structural diagram of the first welding track in FIG;

[0040] Figure 7 This is a schematic structural diagram of the first welding layer of the first welding track of an embodiment of the present application;

[0041] Figure 8 This is a schematic structural diagram of the second welding layer of the first welding track of an embodiment of the present application;

[0042] Figure 9 Schematic diagram of welding positions of the cover plate and the shell body in other embodiments of the present application;

[0043] Figure 10 for Figure 9 Schematic diagram of welding marks formed by corresponding welding methods;

[0044] Figure 11 Schematic diagram of calculation of the overlap rate of solder joints in an embodiment of the present application.

[0045] Description of reference numerals:

[0046] 100-battery;

[0047] 1-battery shell;

[0048] 11-shell body; 110-accommodation cavity; 111-opening; 112-connecting surface; 1121-arc segment; 1122-straight segment;

[0049] 12-cover plate; 12a-first cover plate; 12b-second cover plate;

[0050] 13-second welding track; 131-third welding point;

[0051] 14-first welding track; 141-welding section; 142-first welding point; 143-second welding point;

[0052] 2-Battery cells. DETAILED DESCRIPTION

[0053] In order to make the above-mentioned purposes, features and advantages of the embodiments of the present application more obvious and easy to understand, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0054] With the advancement of science and technology, more and more electrical devices are using batteries as energy storage and supply devices, such as new energy vehicles, communication base stations, and energy storage containers. Currently, the mainstream batteries on the market include prismatic batteries and cylindrical batteries. The battery case is a key component that houses the battery cells and electrolyte. The quality of the weld at the seal has a significant impact on battery performance. However, existing battery cases often suffer from the inability to effectively control the welding heat during the seal welding, resulting in deformation of the battery case.

[0055] In view of this, the present application provides a welding body, a battery shell, a battery and an electrical device. By adopting different welding methods for the arc segment and the straight segment of the battery shell, the welding methods of the arc segment and the straight segment are fully adapted to their respective strengths. While ensuring the welding sealing, the battery shell can be prevented from being deformed due to the concentration of welding heat, and the welding yield between the cover plate and the shell body can be improved, thereby ensuring the quality of the battery.

[0056] The welded body of the embodiment of the present application may refer to an integral structure formed by welding two welded parts (such as a first welded part and a second welded part). In other words, the welded body of the embodiment of the present application includes at least the first welded part and the second welded part.

[0057] Specifically, in the welded body of this embodiment, the first welding member and the second welding member can be welded together to form a first welding track 14. The first welding track 14 can include multiple welding segments, each of which includes a first welding spot 142 and a second welding spot 143. The first welding spot 142 covers at least a portion of the second welding spot 143, and at least some adjacent first welding spots 142 do not overlap. For example, any two adjacent first welding spots 142 can be non-overlapping, or some adjacent first welding spots 142 can be non-overlapping.

[0058] For example, when applied to the battery field, the welded body may refer to a battery shell 1, which may include a shell body 11 and a cover plate 12, wherein the shell body 11 and the cover plate 12 are welded together to form a battery shell 1 with high structural strength and sealing performance. In this case, the cover plate 12 may serve as a first welded part, and the shell body 11 may serve as a second welded part. Of course, the present application is not limited to this. In the field of mechanical manufacturing, welding is a widely used connection technology. When two structural parts need to be welded, the two structural parts can be welded into a welded body as described in the present application according to actual needs.

[0059] For example, combined Figure 1 and Figure 2The battery case 1 can be made of at least one of a variety of metal materials, such as stainless steel, nickel alloy, chromium alloy, and aluminum alloy. The battery case 1 can include a case body 11 and a cover plate 12. At least one end of the case body 11 has an opening 111. The cover plate 12 seals the opening 111 and, together with the case body 11, defines a receiving chamber 110. The battery cell 2 and electrolyte of the battery 100 can be disposed in the receiving chamber 110.

[0060] For example, when the battery 100 is a square-shell battery, the battery shell 1 can be square; when only one end of the shell body 11 is open, the top of the shell body 11 can be open to form an opening 111, and the cover plate 12 can be sealed on the top of the shell body 11 and serve as the top wall of the accommodating cavity 110; or, the top and bottom of the shell body 11 can be open to form an opening 111. In this case, the battery shell 1 can be a square frame composed of four side plates connected in sequence along the circumferential direction. Accordingly, there are two cover plates 12, one of which serves as a top cover plate, sealed on the top opening 111 of the shell body 11, and serves as the top wall of the accommodating cavity 110, and the other cover plate 12 serves as a bottom cover plate, sealed on the bottom opening 111 of the shell body 11, and serves as the bottom wall of the accommodating cavity 110.

[0061] Combine Figure 2 and Figure 4 The shell body 11 has a connecting surface 112 located around the opening 111. The connecting surface 112 is the end surface of the opening of the shell body 11 and surrounds the opening 111. The connecting surface 112 can include a plurality of straight segments 1122 arranged along the circumference of the opening 111, and an arc segment 1121 connecting two adjacent straight segments 1122. In other words, two connected straight segments 1122 can be transitioned through the arc segment 1121, and the radius of the arc segment 1121 can be adjusted as needed.

[0062] Combine Figure 4 The connection surface 112 of the shell body 11 is welded to the cover plate 12. A weld mark is formed at the weld between the shell body 11 and the cover plate 12. The weld mark has the same shape as the connection surface 112, both being annular and surrounding the opening 111. The shell body 11 (e.g., the straight line segment 1122 of the shell body 11) and the cover plate 12 are welded to form a first weld track 14.

[0063] During welding, multiple first welding spots 142 can be formed by spot welding the shell body 11 and the cover plate 12, each first welding spot 142 corresponding to a welding segment. Since two adjacent first welding spots 142 do not overlap, heat concentration between the two first welding spots 142 can be prevented, thereby avoiding deformation of the battery shell 1 area corresponding to the two first welding spots 142.

[0064] In the welded body of the embodiment of the present application, the first weld track 14 between the first weld member and the second weld member includes first weld points 142 and second weld points 143, with at least some adjacent first weld points 142 not overlapping. This prevents heat concentration between the two first weld points 142, and thus prevents deformation of the welded body region corresponding to the first weld track 14. This helps improve the weld yield between the welded bodies and thus ensures weld quality.

[0065] In order to ensure that there is no welding gap on the first welding track, the welding section may further include a plurality of second welding points 143. Optionally, two adjacent non-overlapping first welding points 142 are connected by a second welding point 143. In this way, the welding gap between the two adjacent non-overlapping first welding points 142 can be made up by the second welding point 143, thereby ensuring the sealing of the accommodating cavity 110 after the shell body 11 and the cover plate 12 are welded. In addition, since the second welding point 143 is formed by welding after the first welding point 142 is formed, when the second welding point 143 is formed by welding, the area corresponding to the first welding point 142 has been cooled to a large extent. In this way, it is also possible to prevent the problem of heat concentration in the overlapping area of ​​the second welding point 143 and the first welding point 142, thereby avoiding deformation of the battery shell 1 corresponding to the overlapping area of ​​the second welding point 143 and the first welding point 142.

[0066] For ease of description, the following description takes the welding body as the battery shell 1 , the first welding part as the cover plate 12 of the battery shell 1 , and the second welding part as the shell body 11 of the battery shell 1 as an example.

[0067] In some embodiments, any two adjacent first welding points 142 do not overlap with each other, and the minimum spacing between any two adjacent first welding points 142 is not less than 0.05 mm. That is to say, any two adjacent first welding points 142 belonging to the same first welding track 14 do not overlap with each other. In this way, heat concentration can be prevented in the area corresponding to the first welding layer (i.e., the first welding layer of the first welding track described below), thereby avoiding deformation of the weld body. In addition, the minimum spacing between any two adjacent first welding points 142 is ≥ 0.05 mm. For example, the minimum spacing between any two adjacent first welding points 142 can be 0.05 mm, 0.06 mm, 0.1 mm, 0.2 mm, 0.5 mm, 1 mm, 2 mm or larger. The spacing between any two adjacent first welding points 142 can be equal or unequal, and this embodiment does not limit this. In this way, since during welding, each first weld point 142 corresponds to a heat core area and a heat-affected zone outside the heat core area, by making the minimum spacing between two adjacent first weld points 142 within the above-mentioned range, it is beneficial to reduce the probability of overlapping of the heat-affected zones of two adjacent first weld points 142, thereby reducing the deformation risk of the weld body.

[0068] In some embodiments, two adjacent, non-overlapping first welds 142 are connected by at least one second weld 143. Here, "at least one" refers to one or more, and "more" refers to two or more. The number of second welds 143 between two adjacent, non-overlapping first welds 142 can be adjusted based on the spacing between the two adjacent first welds 142. This ensures that there is no weld gap between the two adjacent, non-overlapping first welds 142, thereby ensuring the weld continuity and sealing of the weld.

[0069] In some embodiments, multiple second welds 143 are located between two adjacent non-overlapping first welds 142, and two adjacent second welds 143 located between two adjacent non-overlapping first welds 142 at least partially overlap. Because multiple second welds 143 are required when the spacing between two adjacent first welds 142 is greater than the size of the first weld 142, the partial overlap of two adjacent second welds 143 helps ensure that there is no welding gap between the two adjacent second welds 143, thereby ensuring the weld continuity of the weld body.

[0070] In some embodiments, the first welding track 14 includes at least one linear track extending in a straight line. Specifically, there is one linear track, or there are multiple linear tracks. For example, when the battery case 1 is a square case, a linear track can be formed on only one side of the connection surface, and other sides and corners can use other tracks. Alternatively, multiple sides can use linear tracks, and each linear track includes multiple welding segments 141.

[0071] It is understandable that the number of welding segments 141 of each straight track can be adaptively adjusted according to the actual length of each straight segment 1122 to ensure the welding quality between the first welding part and the second welding part.

[0072] In some embodiments, the first welding spot 142 covers at least a portion of the adjacent second welding spot 143. In this way, it is possible to ensure that there is no welding gap between two adjacent welding segments 141 of the first welding track 14, thereby ensuring the welding sealing of the battery shell 1.

[0073] In some embodiments, the first welding track 14 may include multiple linear tracks arranged along the circumference of the weld body, wherein the lines along which any two adjacent linear tracks lie are perpendicular to each other. For example, if the battery case 1 is a square case, the connecting surface 112 includes four linear segments located around the square case. Accordingly, the first welding track 14 includes four linear tracks. This ensures the quality of the circumferential welding between the case body 11 and the cover plate 12.

[0074] In some embodiments, a second welding track 13 is formed between the first welding member and the second welding member. The second welding track 13 and the first welding track 14 together constitute the weld mark between the first welding member and the second welding member. The second welding track 13 may include an arcuate track extending in an arc shape. There is at least one arcuate track, where at least one is one or more. Each arcuate track may include multiple third welding spots 131, and adjacent third welding spots 131 may at least partially overlap.

[0075] For example, the connecting surface 112 of the shell body 11 of the battery shell 1 may include a plurality of straight line segments 1122 arranged along the circumference of the opening 111, and an arc segment 1121 connecting two adjacent straight line segments 1122, that is, the two connected straight line segments 1122 can be transitioned through the arc segment 1121, and an arc trajectory can be formed in the arc segment 1121.

[0076] When welding the first welding part and the second welding part, an arc track may be formed first, or a straight track may be formed first, or the arc track and the straight track may be formed simultaneously, which is not limited in this embodiment.

[0077] In this way, when applied to the battery shell 1, by adopting different welding methods for the arc segment 1121 and the straight segment 1122 of the connecting surface 112, and the welding methods of the arc segment 1121 and the straight segment 1122 are fully adapted to their respective strengths, it is possible to avoid deformation of the battery shell 1 due to concentrated welding heat while ensuring welding sealing, thereby improving the welding yield between the cover plate 12 and the shell body 11, and thus ensuring the welding quality of the battery shell 1.

[0078] It is understood that the plurality of third welds 131 can be arranged along the extension direction of the arc segment 1121, with adjacent third welds 131 partially overlapping to ensure that there is no gap between the adjacent third welds 131, thereby ensuring the weld seal between the first and second welds at the arcuate trajectory. It is understood that when welding the first and second welds, the plurality of third welds 131 can be formed by sequentially welding along the extension direction of the arcuate trajectory.

[0079] It should be emphasized that for a square battery case, the strength at both ends of each side plate distributed along the circumference is greater than the strength in the middle, and the length of the arc segment 1121 in the circumferential direction is much smaller than the length of the straight segment 1122. Therefore, in this embodiment, when the second welding track 13 is formed at the arc segment 1121, the plurality of third welding points 131 are arranged sequentially along the extension direction of the arc segment 1121, that is, they are welded sequentially along the extension direction of the arc segment 1121 to form the plurality of third welding points 131. This can improve the welding efficiency at the arc segment 1121 when the strength at the arc segment 1121 allows. When the first welding track 14 is formed at the straight segment 1122, the plurality of first welding points 142 are formed one by one, and the plurality of first welding points 142 of each welding layer are spaced apart. In this way, compared with the welding method at the arc segment 1121, it can avoid the concentration of welding heat when two adjacent first welding points 142 are adjacent or overlapping, reduce the influence of welding heat on the battery shell 1, thereby avoiding deformation of the straight segment 1122 due to welding stress, and is conducive to ensuring the welding yield of the straight segment 1122 and the cover plate 12.

[0080] In other words, the welded body of this embodiment adopts different welding methods for the arc segment 1121 and the straight segment 1122, so that the welding methods of the arc segment 1121 and the straight segment 1122 are fully adapted to their respective strengths. While ensuring the welding sealing, the welded body can be avoided from deformation, the welding yield between the first welded part and the second welded part can be improved, and thus the quality of the welded body can be guaranteed.

[0081] In some embodiments, any two adjacent straight segments 1122 along the circumference of the opening 111 are perpendicular to each other, and the arc segment 1121 is located at the corner position defined by the two adjacent straight segments 1122, that is, the arc trajectory is located at the corner position defined by the two adjacent straight trajectory. For example, the shell body 11 is formed into a square structure with chamfers, and the shell body 11 has a first direction (such as Figure 1 The two first straight line segments 1122 opposite to each other in the X direction (ie, the width direction of the shell body 11) and the two first straight line segments 1122 along the second direction (eg Figure 1 In the Y direction (as shown, i.e., the length direction of the shell body 11), there are two opposite second straight segments 1122, and four arc segments 1121, each of which is located at a corner corresponding to the connection between the first straight segment 1122 and the second straight segment 1122. In this way, the welding method of the second welding track 13 is more suitable for the strength of the arc segment 1121, and the welding method of the first welding track 14 is more suitable for the strength of the straight segment 1122, which can better ensure the welding quality of the battery shell 1.

[0082] It can be understood that the lengths of the first straight segment 1122 and the second straight segment 1122 are different. Therefore, the number of welding segments 141 in the first straight segment 1122 and the second straight segment 1122, and the number of first welding points 142 and second welding points 143 in each welding segment 141 can be different and can be reasonably adjusted as needed.

[0083] In some embodiments, the overlap rate between any two overlapping third welding points 131 on the second welding trajectory 13 is a, and the maximum overlap rate between the first welding point 142 and the adjacent second welding point 143 is b, and a and b are not equal. In this way, it is convenient to adopt corresponding welding methods according to the respective structural characteristics of the arc trajectory and the straight line trajectory to ensure the welding quality while taking into account their respective welding efficiency.

[0084] Combine Figure 11 Here, the overlapping ratio of two third welding points 131 is taken as an example to illustrate the calculation method of the overlapping ratio of two adjacent welding points (including the first welding point 142, the second welding point 143, and the third welding point 131) in the embodiment of the present application: If the reference circle determined by the outer contour of the orthographic projection of the third welding point 131 in the thickness direction of the first weld is the third reference circle, the overlapping ratio a of the two third welding points 131 can be understood as the overlapping distance L (i.e., Figure 11 The ratio of the diameter L) to the diameter D of the third reference circle, that is, a=L / D.

[0085] It can be understood that the overlap distance L may be the distance between the straight line connecting the centers of the two third reference circles corresponding to two adjacent overlapping third welding points 131 at the overlapped position.

[0086] In some embodiments, the overlap distance can be adjusted by adjusting the distance between the centers of the third reference circles corresponding to two adjacent third welding points 131. The greater the overlap rate between two adjacent third welding points 131, the greater the overlap distance between the two adjacent third welding points 131.

[0087] It can be understood that the calculation method of b and c described below is the same as a, and will not be repeated here.

[0088] That is, the outer contour of the orthographic projection of any one of the first welding spot 142 , the second welding spot 143 , and the third welding spot 131 in the thickness direction of the first weld may be a circle or close to a circle.

[0089] In some embodiments, a and b satisfy the following: a>b, that is, the overlap ratio between any two overlapping third welds 131 on the second welding track 13 is greater than the maximum overlap ratio between the overlapping first welds 142 and second welds 143 on the first welding track 14. In this embodiment, a relatively larger overlap ratio between the two third welds 131 helps ensure the welding reliability of the first and second welds in the area corresponding to the arcuate track, while also reducing the welding difficulty in the area corresponding to the arcuate track. In addition, a relatively smaller maximum overlap ratio between the overlapping first and second welds 142 and 143 on the first welding track 14 helps avoid heat concentration and reduce deformation of the welded body, thereby improving the welding yield between the first and second welds and contributing to improved welding efficiency.

[0090] In some embodiments, the value range of a is: 40% ≤ a ≤ 70%. For example, the value of a can be 40%, 45%, 50%, 55%, 60%, 65%, or 70%. Of course, the present application is not limited thereto, and the value of a can be reasonably set within the above range according to actual needs. This is to avoid a value that is too small, such as less than 40%, which leads to reduced welding reliability between the first welded part and the second welded part; and to avoid a value that is too large, such as greater than 70%, which leads to excessively low welding efficiency.

[0091] The value range of b is: 35% ≤ b ≤ 65%. For example, the value of b can be 35%, 40%, 45%, 50%, 55%, 60%, or 65%. Of course, the present application is not limited thereto, and the value of b can be reasonably set within the above range according to actual needs. This is to avoid a reduction in the welding reliability between the first welded part and the second welded part when the value of b is too small, such as less than 35%, and to avoid excessive concentration of welding heat and deformation of the welded part when the value of b is too large, such as greater than 65%.

[0092] In some embodiments, at the connection between the second welding track 13 and the first welding track 14, the third welding point 131 and the first welding point 142 or the second welding point 143 partially overlap. In this way, the welding continuity with the second welding track 13 and the first welding track 14 can be further ensured, which is conducive to improving the welding quality.

[0093] In some embodiments, at the junction of the second welding track 13 and the first welding track 14, the overlap ratio c of the overlapping third welding spot 131 and the second welding spot 143 or the third welding spot 131 and the first welding spot 142 is in the range of 40%≤c≤70%. For example, the value of c can be 40%, 45%, 50%, 55%, 60%, 65% or 70%. Of course, the present application is not limited thereto, and the value of c can be reasonably set within the above range according to actual needs. This is to avoid the situation where the value of c is too small, for example, less than 40%, resulting in reduced welding reliability of the first welding part and the second welding part at the intersection of the first welding track 14 and the second welding track 13; and to avoid the situation where the value of c is too large, for example, greater than 70%, resulting in reduced welding efficiency and heat concentration on one side of the first welding track 14, resulting in deformation of the weld body.

[0094] In some embodiments, reference Figure 6 , the welding trajectory is an arc, and the range of the radius R of the arc trajectory is: 0.5mm≤R≤2mm. For example, the value of the radius R of the arc trajectory can be 0.5mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 1.8mm or 2mm. Of course, the present application is not limited to this, and the value of R can be reasonably set within the above range according to actual needs. To avoid the value of R being too small, for example, less than 0.5mm, which makes welding the first weld and the second weld more difficult; and to avoid the value of R being too large, for example, greater than 2mm, which increases the influence of welding heat on the weld body. That is, by making the R value within the above range, the influence of heat on the weld body 1 can be reduced during welding, and the possibility of deformation of the weld body can be reduced.

[0095] In some embodiments, reference Figure 7 and Figure 8 The distance between any two adjacent first welding spots 142 is equal. Thus, after forming one first welding spot 142, the welding beam is moved a specific distance to another first welding spot 142, and so on, until all first welding spots 142 are formed. This makes the welding process relatively simple and easy to implement.

[0096] In some embodiments, combined Figure 3 and Figure 4 as well as Figure 9 and Figure 10The ratio of the area of ​​the third weld point 131 to the area of ​​the third reference circle is 0.5-1, wherein the third reference circle is a circle determined according to the outer contour of the positive projection of the third weld point 131 in the thickness direction of the first weld part, and the area of ​​the third weld point 131 refers to the complete area of ​​the third weld point 131 in the thickness direction of the first weld part, including the area of ​​the third weld point 131 exposed in the thickness direction of the first weld part and the part covered due to overlap, that is, after the third reference circle completely overlaps with the exposed outer contour of the third weld point 131, the area corresponding to the third reference circle between the first weld part and the second weld part.

[0097] For example, the ratio of the area of ​​the third welding point 131 to the area of ​​the third reference circle can be 0.5, 0.6, 0.7, 0.8, 0.9 or 1. Of course, this application does not limit this. The ratio of the area of ​​the third welding point 131 to the area of ​​the third reference circle can be reasonably selected within the above range as needed. Figure 9 and Figure 10 , when the welding beam of the welding device used to form the second welding track 13 (ie Figure 9 When the arrow in the figure acts on the edge of the connecting surface 112 of the shell body 11, the third welding point 131 is formed into a semicircular shape (such as Figure 10 As shown), at this time, the ratio of the area of ​​the third welding point 131 to the area of ​​the third reference circle is 0.5; Figure 3 and Figure 4 , when the welding beam of the welding device used to form the second welding track 13 (ie Figure 3 When the arrow in the figure acts on the center of the connecting surface 112, the third welding point 131 is formed into a complete circle (such as Figure 4 As shown), at this time, the ratio of the area of ​​the third welding point 131 to the area of ​​the third reference circle is 1.

[0098] In some embodiments, the ratio of the area of ​​the first weld 142 to the area of ​​the first reference circle is 0.5-1, wherein the first reference circle is a circle determined based on the outer contour of the positive projection of the first weld 142 in the thickness direction of the first weld, and the area of ​​the first weld 142 refers to the complete area of ​​the first weld 142 in the thickness direction of the first weld, including the exposed area of ​​the first weld 142 in the thickness direction of the first weld and the part covered due to overlap, that is, the area corresponding to the first reference circle between the first weld and the second weld after the first reference circle completely overlaps with the exposed outer contour of the first weld 142.

[0099] For example, the ratio of the area of ​​the first weld point 142 to the area of ​​the first reference circle can be 0.5, 0.6, 0.7, 0.8, 0.9 or 1. Of course, this application does not impose any restrictions on this. The ratio of the area of ​​the first weld point 142 to the area of ​​the first reference circle can be reasonably selected within the above range as needed. For example, when the welding beam of the welding equipment used to form the first weld track 14 acts on the edge of the connecting surface 112 of the shell body 11, the first weld point 142 is formed into a semicircle. At this time, the ratio of the area of ​​the first weld point 142 to the area of ​​the first reference circle is 0.5; when the welding beam of the welding equipment used to form the first weld track 14 acts on the center position of the connecting surface 112, the first weld point 142 is formed into a complete circle. At this time, the ratio of the area of ​​the first weld point 142 to the area of ​​the first reference circle is 1.

[0100] In some embodiments, combined Figure 3 and Figure 4 as well as Figure 9 and Figure 10 The ratio of the area of ​​the second weld 143 to the area of ​​the second reference circle is 0.5-1, wherein the second reference circle is a circle determined according to the outer contour of the positive projection of the second weld 143 in the thickness direction of the first weld part, and the area of ​​the second weld 143 refers to the complete area of ​​the second weld 143 in the thickness direction of the first weld part, including the exposed area of ​​the second weld 143 in the thickness direction of the first weld part and the part covered due to overlap, that is, the area corresponding to the second reference circle between the first weld part and the second weld part after the second reference circle completely overlaps with the exposed outer contour of the second weld 143.

[0101] For example, the ratio of the area of ​​the second welding point 143 to the area of ​​the second reference circle can be 0.5, 0.6, 0.7, 0.8, 0.9 or 1. Of course, this application does not limit this. The ratio of the area of ​​the second welding point 143 to the area of ​​the second reference circle can be reasonably selected within the above range as needed. Figure 9 and Figure 10 , when the welding beam of the welding device used to form the second welding track 13 (ie Figure 9 When the arrow in the figure acts on the edge of the connecting surface 112 of the shell body 11, the second welding point 143 is formed into a semicircular shape (such as Figure 10 As shown), at this time, the ratio of the area of ​​the second welding point 143 to the area of ​​the second reference circle is 0.5; Figure 3 and Figure 4 , when the welding beam of the welding device used to form the second welding track 13 (ie Figure 3 When the arrow in the figure acts on the center of the connecting surface 112, the second welding point 143 is formed into a complete circle (such as Figure 4As shown), at this time, the ratio of the area of ​​the second welding point 143 to the area of ​​the second reference circle is 1.

[0102] Optionally, the ratio of the area of ​​the third welding point 131 to the area of ​​the third reference circle, the ratio of the area of ​​the second welding point 143 to the area of ​​the second reference circle, and the ratio of the area of ​​the first welding point 142 to the area of ​​the first reference circle may be the same or different.

[0103] In some embodiments, reference Figure 9 The thickness W1 of the second weld member is in the range of 0.1 mm ≤ W1 ≤ 0.3 mm. That is, the width of the connection surface 112 of the shell body 11 is in the range of 0.1 mm to 0.3 mm. For example, the thickness W1 of the second weld member may be 0.1 mm, 0.2 mm, or 0.3 mm. This is not a limitation of the present application. The thickness W1 of the second weld member may be adjusted based on actual needs to ensure sufficient strength of the second weld member and a sufficient connection area between the first weld member and the second weld member.

[0104] Optional, reference Figure 9 The value range of the thickness W2 of the first weld part is: 0.03mm≤W2≤0.1mm. For example, the thickness W2 of the first weld part (the cover plate 12 described below) can be 0.03mm, 0.05mm, 0.08mm or 0.1mm. Of course, the present application does not limit this. The value of the thickness W2 of the first weld part can be adjusted according to actual needs to prevent the thickness of the first weld part from being too small, for example, less than 0.03mm, and the strength of the first weld part is too small, which is easy to deform due to welding stress; and to avoid the thickness of the first weld part being too large, for example, greater than 0.1mm, and the welding energy is difficult to effectively penetrate the first weld part to reach the second weld part, resulting in problems such as cold welding, false welding or low welding stability.

[0105] Optionally, refer to Figure 5 The diameter W3 of the third reference circle determined by the outer contour of the orthographic projection of the third weld point 131 in the thickness direction of the first weld part has a value range of: 0.1mm≤W3≤0.3mm. For example, the diameter W3 of the third reference circle can be 0.1mm, 0.2mm or 0.3mm. Of course, this is not limited in the present application. The value of the diameter W3 of the third reference circle can be adjusted according to actual needs to avoid the diameter of the third reference circle being too small, for example, when it is less than 0.1mm, the connection area between the first weld part and the second weld part is too small, resulting in reduced welding reliability; in addition, it is also necessary to avoid the diameter of the third weld point 131 being too large, for example, when it is greater than 0.3mm, the welding beam corresponding to the third weld point 131 is larger than the thickness W1 of the second weld part, resulting in ineffective welding and wasted energy.

[0106] Optionally, refer to Figure 6 The value range of the diameter W4 of the first reference circle determined by the outer contour of the orthographic projection of the first weld 142 in the thickness direction of the first weld part is: 0.1mm≤W4≤0.3mm. For example, the diameter W4 of the first reference circle can be 0.1mm, 0.2mm or 0.3mm. Of course, this is not limited in the present application. The value of the diameter W4 of the first reference circle can be adjusted according to actual needs to avoid the diameter of the first weld 142 being too small, for example, when it is less than 0.1mm, the connection area between the first weld part and the second weld part is too small, resulting in reduced welding reliability; in addition, it is also necessary to avoid the diameter of the first weld 142 being too large, for example, when it is greater than 0.3mm, the welding beam corresponding to the first weld 142 is larger than the thickness W1 of the second weld part, resulting in ineffective welding and wasted energy.

[0107] Optionally, refer to Figure 6 The value range of the diameter W5 of the second reference circle determined by the outer contour of the orthographic projection of the second weld 143 in the thickness direction of the first weld part is: 0.1mm≤W5≤0.3mm. For example, the diameter W5 of the second reference circle can be 0.1mm, 0.2mm or 0.3mm. Of course, this is not limited in the present application. The value of the diameter W5 of the second reference circle can be adjusted according to actual needs to avoid the diameter of the second weld 143 being too small. For example, when it is less than 0.1mm, the connection area between the first weld part and the second weld part is too small, resulting in reduced welding reliability. In addition, it is also necessary to avoid the diameter of the second weld 143 being too large. For example, when it is greater than 0.3mm, the welding beam corresponding to the second weld 143 is larger than the thickness W1 of the second weld part, resulting in ineffective welding and wasted energy.

[0108] In some embodiments, reference Figure 4 The second welding track 13 is connected to the first welding track 14. For example, the third welding spot 131 and the first welding spot 142 at the connection between the second welding track 13 and the first welding track 14 can be adjacent but not overlapping; alternatively, the third welding spot 131 and the first welding spot 142 at the connection between the second welding track 13 and the first welding track 14 can partially overlap; alternatively, the third welding spot 131 and the second welding spot 143 at the connection between the second welding track 13 and the first welding track 14 can partially overlap. In this way, the connection surface 112 can be welded to the cover plate 12 along the entire circumference, thereby ensuring the stability and reliability of the welding between the shell body 11 and the cover plate 12.

[0109] In some embodiments, at the overlap between the second welding track 13 and the first welding track 14, the first welding track 14 is located on the side of the second welding track 13 closer to the first welded component (i.e., above), or the second welding track 13 is located on the side of the first welding track 14 closer to the first welded component (i.e., above). For example, when the arcuate segment 1121 of the shell body 11 and the cover plate 12 are welded first, the first welding track 14 is located above the second welding track 13; when the straight segment 1122 of the shell body 11 and the cover plate 12 are welded first, the second welding track 13 is located above the first welding track 14. In this way, the welding methods for the shell body 11 and the cover plate 12 of this embodiment are relatively diverse and can be flexibly selected according to needs.

[0110] In some embodiments, the first welding track 14 includes a first welding layer and a second welding layer. The first welding layer includes a plurality of first welding spots 142 of welding segments 141, and the second welding layer includes a plurality of second welding spots 143 of welding segments 141. The first welding layer covers at least a portion of the second welding layer. In other words, the first welding track of this embodiment is divided into at least two welding layers, and the two welding layers are formed sequentially. For example, the first welding layer is formed first, followed by the second welding layer, or the second welding layer is formed first, followed by the first welding layer.

[0111] Taking the formation of the first welding layer as an example, the first welding points 142 of the plurality of welding segments 141, i.e., the first welding layer, can be formed by spot welding the first welding part and the second welding part, and then welding is performed between two adjacent first welding points 142 to form the second welding points 143 of the welding segment 141, i.e., the second welding layer. In this way, heat concentration can be prevented between the two first welding points 142, thereby preventing deformation of the battery shell 1 corresponding to the two first welding points 142. Moreover, since the second welding layer is formed by welding after the first welding layer is formed, the area corresponding to the first welding layer has been cooled to a large extent when the second welding layer is formed by welding. In this way, the problem of heat concentration in the overlapping area of ​​the first welding layer and the second welding layer can also be prevented, thereby preventing deformation of the weld body.

[0112] The battery case 1 according to an embodiment of the present application is described below.

[0113] The battery shell 1 of this embodiment constitutes the above-mentioned welded body. Specifically, the battery shell 1 provided in the embodiment of the present application can be made of at least one of a variety of metal materials such as stainless steel, nickel alloy, chromium alloy, aluminum alloy, etc. The battery shell 1 may include a shell body 11 and a cover plate 12. At least one end of the shell body 11 has an opening 111. The cover plate 12 is sealed at the opening 111 and defines a accommodating cavity 110 together with the shell body 11. The battery cell 2 and the electrolyte of the battery 100 can be arranged in the accommodating cavity 110. Among them, the cover plate 12 can constitute the first welded part of the above-mentioned welded body, and the shell body 11 can constitute the second welded part of the above-mentioned welded body.

[0114] For example, when the battery 100 is a square-shell battery, the battery shell 1 can be square; when only one end of the shell body 11 is open, the top of the shell body 11 can be open to form an opening 111, and the cover plate 12 can be sealed on the top of the shell body 11 and serve as the top wall of the accommodating cavity 110; or, the top and bottom of the shell body 11 can be open to form an opening 111. In this case, the battery shell 1 can be a square frame composed of four side plates connected in sequence along the circumferential direction. Accordingly, there are two cover plates 12, one of which serves as a top cover plate, sealed on the top opening 111 of the shell body 11, and serves as the top wall of the accommodating cavity 110, and the other cover plate 12 serves as a bottom cover plate, sealed on the bottom opening 111 of the shell body 11, and serves as the bottom wall of the accommodating cavity 110.

[0115] Combine Figure 2 and Figure 4 The shell body 11 has a connecting surface 112 located around the opening 111. The connecting surface 112 is the end surface of the opening of the shell body 11 and surrounds the opening 111. The connecting surface 112 can include a plurality of straight segments 1122 arranged along the circumference of the opening 111, and an arc segment 1121 connecting two adjacent straight segments 1122. In other words, two connected straight segments 1122 can be transitioned through the arc segment 1121, and the radius of the arc segment 1121 can be adjusted as needed.

[0116] Combine Figure 4 The connection surface 112 of the shell body 11 is welded to the cover plate 12. A weld mark is formed at the weld between the shell body 11 and the cover plate 12. The weld mark has the same shape as the connection surface 112, both being annular and surrounding the opening 111. The shell body 11 (e.g., the straight line segment 1122 of the shell body 11) and the cover plate 12 are welded to form a first weld track 14.

[0117] In some embodiments, openings 111 are formed at opposite ends of the shell body 11. There are two cover plates 12, namely a first cover plate 12a and a second cover plate 12b. The first cover plate 12a can serve as a top cover plate 12, which is sealed at the top opening 111 of the shell body 11 and serves as the top wall of the accommodating cavity 110. The second cover plate 12b can serve as a bottom cover plate 12, which is sealed at the bottom opening 111 of the shell body 11 and serves as the bottom wall of the accommodating cavity 110. The two cover plates 12 are respectively welded to the connecting surfaces 112 at the two openings 111 of the shell body 11 to form a second welding track 13 and a first welding track 14. In this way, the structure of the battery shell 1 is relatively simple and easy to manufacture.

[0118] The battery 100 according to an embodiment of the present application is described below.

[0119] The battery 100 provided in this embodiment can be a primary battery or a secondary battery. A primary battery refers to a battery that cannot be recharged and reused after discharge, and a secondary battery refers to a battery that can be recharged to activate the active material and continue to be used after discharge. 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. The battery 100 can be a square-shell battery, a cylindrical battery, or a soft-pack battery, or can be of other shapes. The embodiments of the present application are not limited to this, and the embodiments of the present application are specifically described using a square-shell battery as an example.

[0120] Combine Figure 1 and Figure 2 The battery 100 of this embodiment includes a battery shell 1 and a battery cell 2 located in the battery shell 1.

[0121] According to the battery 100 of the embodiment of the present application, by providing the battery shell 1 implemented above, the battery shell 1 can better accommodate and protect the internal battery cells and other components due to the higher welding quality of the battery shell 1, which is beneficial to improving the quality of the battery 100. In some embodiments, reference Figure 2 The battery 100 may further include a battery cell 2, which is disposed in the inner cavity of the battery shell 1. The battery cell 2 may include a first electrode sheet, a second electrode sheet, and a separator, wherein the polarities of the first electrode sheet and the second electrode sheet are opposite. For example, the first electrode sheet may be a positive electrode sheet, and the second electrode sheet may be a negative electrode sheet. Taking the first electrode sheet as a positive electrode sheet and the second electrode sheet as a negative electrode sheet as an example, the first electrode sheet may include a positive electrode current collector and a positive electrode active layer coated on the surface of the positive electrode current collector, and the second electrode sheet may include a negative electrode current collector and a negative electrode active layer coated on the surface of the negative electrode current collector. When the battery cell 2 is a wound battery cell, the first electrode sheet, the separator, and the second electrode sheet are stacked in sequence and then wound; when the battery cell 2 is a laminated battery cell, there are multiple first electrode sheets, separators, and second electrode sheets, and the first electrode sheets and the second electrode sheets are alternately stacked, and adjacent first electrode sheets and second electrode sheets are separated by separators.

[0122] The battery cell 2 is further provided with a first tab extending from the first electrode piece and a second tab extending from the second electrode piece. The shell body 11 of the battery case 1 may be provided with a pole, which is insulated from the shell body 11. The pole can be electrically connected to the first tab, and the shell body 11 can be electrically connected to the second tab. Alternatively, the shell body 11 may further be provided with a second pole, which is insulated from the shell body 11 and electrically connected to the second tab. In this way, the battery cell 2 can be electrically connected to the battery case 1, thereby enabling the battery 100 to transmit power to the outside.

[0123] This embodiment further provides an electric device, which may be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, etc. This embodiment of the application does not impose any special restrictions on the electric device.

[0124] The electrical device of this embodiment may include a device body and the battery 100 of the above embodiment. The device body may be provided with a battery compartment, which may be provided with a power supply interface. The battery 100 may be provided in the battery compartment and electrically connected to the power supply interface to power the electrical device.

[0125] According to the electrical equipment of the embodiment of the present application, by providing the battery 100 of the above embodiment, the electrical performance can be improved due to the higher welding quality of the battery 100, thereby better powering the electrical equipment.

[0126] The various embodiments or implementation methods in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referenced to each other.

[0127] It should be noted that phrases such as "one embodiment," "an embodiment," "exemplary embodiments," and "some embodiments" in this specification may indicate embodiments that may include a particular feature, structure, or characteristic, but not every embodiment necessarily includes that particular feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in conjunction with an embodiment, it is within the knowledge of those skilled in the art to implement such feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not.

[0128] Generally speaking, terms should be understood, at least in part, based on the context in which they are used. For example, as used herein, the term "one or more" can be used to describe any feature, structure, or characteristic in the singular sense, or can be used to describe a combination of features, structures, or characteristics in the plural sense, depending at least in part on the context. Similarly, terms such as "a," "an," or "the" can also be understood to convey either singular or plural usage, depending at least in part on the context.

[0129] It should be readily understood that “on,” “above,” and “over” in this disclosure should be interpreted in the broadest manner, such that “on” means not only “directly on something,” but also includes “on something” with intervening features or layers therebetween, and “above” or “over” includes not only the meaning of “above” or “over,” but also includes “above” or “over” with no intervening features or layers therebetween (i.e., directly on something).

[0130] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A welded body, characterized in that: include: a first welding piece and a second welding piece, wherein a first welding track (14) is formed between the first welding piece and the second welding piece, The first welding track (14) includes a plurality of welding segments, each of the welding segments includes a first welding spot (142) and a second welding spot (142), the first welding spot (142) covers at least a portion of the second welding spot (143), and at least a portion of adjacent first welding spots (142) do not overlap with each other.

2. The welded body according to claim 1, wherein: Any two adjacent first welding spots (142) do not overlap each other, and the minimum spacing between any two adjacent first welding spots (142) is not less than 0.05 mm.

3. The welded body according to claim 1, wherein: Two adjacent non-overlapping first welding points (142) are connected via at least one second welding point (143).

4. The welded body according to claim 3, wherein: There are multiple second welding spots (143) between two adjacent non-overlapping first welding spots (142), and two adjacent second welding spots (143) located between two adjacent non-overlapping first welding spots (142) at least partially overlap.

5. The welded body according to claim 3, wherein: The first welding spot (142) covers at least a portion of the adjacent second welding spot (143).

6. The welded body according to claim 1, wherein: The first welding track (14) includes at least one straight track extending in a straight line, and the straight track includes a plurality of welding segments.

7. The welded body according to claim 6, wherein: The first welding track (14) comprises a plurality of linear tracks, wherein the straight lines on which any two adjacent linear tracks lie are perpendicular to each other.

8. The welded body according to claim 1, wherein: A second welding track is formed between the first welding part and the second welding part, the second welding track includes at least one arc-shaped track extending in an arc shape, the arc-shaped track includes a plurality of third welding points (131), and two adjacent third welding points (131) at least partially overlap.

9. The welded body according to claim 8, wherein: The first welding track (14) comprises a plurality of straight track tracks, wherein the straight lines on which any two adjacent straight track tracks are located are perpendicular to each other, and the arc track is located at a corner position defined by the two adjacent straight track tracks.

10. The welded body according to claim 8, wherein: The overlap rate between any mutually overlapping third welding points on the second welding track (13) is a, and the value range of a is: 40%≤a≤80%.

11. The welded body according to claim 10, wherein: Two adjacent non-overlapping first welding points (142) are connected via at least one second welding point (143), the first welding point (142) covers at least a portion of the adjacent second welding point (143), the maximum overlap rate between the first welding point and the adjacent second welding point is b, and a and b are not equal.

12. The welded body according to claim 11, wherein: a and b satisfy: a>b.

13. The welded body according to claim 12, wherein: The value range of b is: 35%≤b≤70%.

14. The welded body according to claim 8, wherein The arc track is in the shape of a circular arc, and the range of the radius R of the arc track is: 0.5mm≤R≤2mm.

15. The welded body according to claim 8, wherein The second welding track (13) is connected to the first welding track (14).

16. The welded body according to claim 15, characterized in that The third welding point (131) of the second welding track (13) and the first welding point or the second welding point of the first welding track (14) partially overlap at the connection point.

17. The welded body according to claim 16, wherein: The overlapping rate c of the second welding point (143) and the third welding point (131) or the first welding point (142) and the third welding point (131) at the connection point where the second welding track (13) and the first welding track (14) overlap each other is in the range of 40%≤c≤70%.

18. The welded body according to claim 8, wherein: At the overlapping portion of the second welding track (13) and the first welding track (14), the first welding track (14) is located on a side of the second welding track (13) close to the first welding part, or the second welding track (13) is located on a side of the first welding track (14) close to the first welding part.

19. The welded body according to claim 8, wherein: The ratio of the area of ​​the first welding spot (142) to the area of ​​the first reference circle is 0.5-1, wherein the first reference circle is a circle determined according to the outer contour of the orthographic projection of the first welding spot (142) in the thickness direction of the first welded part; and / or, The ratio of the area of ​​the second welding spot (143) to the area of ​​the second reference circle is 0.5-1, wherein the second reference circle is a circle determined according to the outer contour of the orthographic projection of the second welding spot (143) in the thickness direction of the first welding part; and / or, The ratio of the area of ​​the third welding point (131) to the area of ​​the third reference circle is 0.5-1, wherein the third reference circle is a circle determined according to the outer contour of the positive projection of the third welding point (131) in the thickness direction of the first welding part.

20. The welded body according to claim 8, wherein The diameter W3 of the third reference circle determined by the outer contour of the orthographic projection of the third welding point (131) in the thickness direction of the first welding part has a value range of: 0.1mm≤W3≤0.3mm.

21. The welded body according to claim 1, wherein The thickness W1 of the second welded part has a value range of: 0.1 mm ≤ W1 ≤ 0.3 mm; and / or, The thickness W2 of the first welded part has a value range of: 0.03 mm ≤ W2 ≤ 0.1 mm; and / or, The diameter W4 of the first reference circle determined by the outer contour of the orthographic projection of the first welding point (142) in the thickness direction of the first welding part has a value range of: 0.1mm≤W4≤0.3mm; and / or, The diameter W5 of the second reference circle determined by the outer contour of the orthographic projection of the second welding point (143) in the thickness direction of the first welding part has a value range of: 0.1mm≤W5≤0.3mm.

22. The welded body according to any one of claims 1 to 21, characterized in that The distance between any two adjacent first welding points (142) is equal.

23. The welded body according to any one of claims 1 to 21, characterized in that The first welding track (14) includes a first welding layer and a second welding layer, the first welding layer includes a plurality of the first welding spots (142) of the welding segments (141), the second welding layer includes a plurality of the second welding spots (143) of the welding segments (141), and the first welding layer covers at least a portion of the second welding layer.

24. A battery case (1), characterized in that: The battery shell (1) constitutes a welded body according to any one of claims 1 to 23, and the battery shell (1) comprises: a shell body (11) and a cover plate (12), wherein at least one end of the shell body (11) has an opening (111), and the cover plate (12) is sealed at the opening (111) and defines a receiving cavity (110) together with the shell body (11). The cover plate (12) constitutes a first welding part of the welding body, and the shell body (11) constitutes a second welding part of the welding body.

25. The battery housing (1) according to claim 24, characterized in that The shell body (11) is provided with openings (111) at opposite ends thereof, and there are two cover plates (12). The two cover plates (12) respectively cover the openings (111) at both ends of the shell body (11), and the shell body (11) is welded to each of the cover plates (12) to form the first welding track (13) and the second welding track (14).

26. A battery (100), characterized in that It comprises a battery core (2) and a battery shell (1) according to claim 24 or 25, wherein the battery core (2) is located in a receiving cavity (110) of the battery shell (1).

27. An electrical device, characterized in that: Comprising the battery (100) of claim 26.

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