Battery

Abstract

The utility model relates to the technical field of batteries, and discloses a battery which comprises a shell, at least one end of the shell is open, and the shell wall of the shell is thinned at the open end so as to form at least one step structure in the shell; the cover plate blocks the opening and is welded to the shell, and the cover plate abuts against the step structure; wherein in the circumferential direction, surrounding the opening, of the shell, the perimeter of the shell is a, the total length of the step structure is b, and the formula that b / a is larger than or equal to 0.02 and smaller than or equal to 0.98 is met. According to the utility model, the ratio of the perimeter of the shell to the total length of the step structure is limited, so that the positioning effect of the step structure on the cover plate is ensured, the assembly quality and the welding quality of the cover plate and the shell are ensured, the shell wall of the opening end of the shell has enough thickness, and the service life of the shell is prolonged. Therefore, the structural strength of the shell is ensured, the welding requirements of the cover plate and the shell are met, and the problems of cracking of a welding wire and the like are avoided.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to batteries. Background Technology

[0002] A battery typically comprises an internal structure and an external structure. The external structure includes a casing that encloses a space, while the internal structure includes the battery cells, which are housed within this space. The casing usually consists of a shell and a cover plate. To facilitate the positioning and assembly of the cover plate onto the shell, a stepped structure is typically formed at the shell opening to allow the cover plate to abut and be positioned, before the cover plate and shell are welded together. However, the stepped structure reduces the thickness of the shell at the opening, resulting in poorer structural strength of the shell and also weakening the weld strength between the cover plate and the shell. Under fatigue loads, this can lead to cracking of the weld lines. Utility Model Content

[0003] In view of this, the present invention provides a battery to solve the problem in the prior art where the thickness of the casing at the casing opening is reduced, resulting in poor structural strength of the casing and poor welding strength between the cover plate and the casing.

[0004] This utility model provides a battery, comprising: a casing with an opening at at least one end, wherein the casing wall is thinned at the opening end to form at least one stepped structure inside the casing; a cover plate, which seals the opening and is welded to the casing, wherein the cover plate abuts against the stepped structure; wherein, in the circumferential direction of the casing surrounding the opening, the circumference of the casing is a, and the total length of the stepped structure is b, satisfying 0.02≤b / a≤0.98.

[0005] Beneficial effects: By limiting the ratio of the perimeter of the shell to the total length of the stepped structure, the positioning effect of the stepped structure on the cover plate is guaranteed, thus ensuring the assembly and welding quality of the cover plate and the shell. At the same time, the shell wall at the opening end of the shell has sufficient thickness to ensure the structural strength of the shell and meet the welding requirements of the cover plate and the shell, avoiding problems such as weld line cracking. Specifically, if b / a > 0.98, the length of the stepped structure is too large, resulting in an excessively long area of ​​shell wall thinning. This leads to poor structural strength at the open end, making the shell prone to deformation or even breakage. Furthermore, the excessively long thinning area also results in poor welding strength between the cover plate and the shell, leading to low welding quality, weld cracking, and ultimately, assembly failure of the shell and cover plate. Conversely, if b / a < 0.02, the length of the stepped structure is too small, resulting in insufficient restraint on the cover plate. This affects the assembly efficiency of the cover plate and shell and easily causes misalignment. Higher welding strength is required to ensure reliable connection between the cover plate and shell. However, insufficient welding strength can also easily lead to assembly failure. Attached Figure Description

[0006] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0007] Figure 1 This is a schematic diagram of the structure of a shell according to an embodiment of the present utility model;

[0008] Figure 2 for Figure 1 A magnified view of part A in the diagram;

[0009] Figure 3 for Figure 1 The top view of the casing shown;

[0010] Figure 4 for Figure 3 A magnified view of part B in the diagram;

[0011] Figure 5 This is a schematic diagram of the structure of a battery (cell not shown) according to an embodiment of the present utility model;

[0012] Figure 6 for Figure 5 A top view of the battery shown;

[0013] Figure 7 for Figure 6 A cross-sectional view along the CC direction;

[0014] Figure 8 for Figure 7 A magnified view of part of D;

[0015] Figure 9 for Figure 8 A schematic diagram of another embodiment of the cover plate shown.

[0016] Explanation of reference numerals in the attached figures:

[0017] 1. Shell; 11. Stepped structure; 12. Edge; 13. Shell opening; 131. Second rounded corner; 14. Main body; 141. First rounded corner; 15. First plate; 16. Second plate; 2. Cover plate; 21. Embedded part; 22. Covering part; 3. Accommodating space. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0019] The following is combined Figures 1 to 9 The following describes embodiments of the present invention.

[0020] According to an embodiment of the present invention, a battery is provided, comprising: a housing 1, with an opening at at least one end, wherein the housing wall of the housing 1 is thinned at the opening end to form at least one stepped structure 11 inside the housing 1; a cover plate 2, which seals the opening and is welded to the housing 1, wherein the cover plate 2 abuts against the stepped structure 11; wherein, in the circumferential direction around the opening of the housing 1, the circumference of the housing 1 is a, and the total length of the stepped structure 11 is b, satisfying 0.02≤b / a≤0.98.

[0021] The battery of this embodiment limits the ratio of the perimeter of the shell 1 to the total length of the stepped structure 11. This ensures the positioning effect of the stepped structure 11 on the cover plate 2, thereby ensuring the assembly and welding quality of the cover plate 2 and the shell 1. At the same time, it ensures that the shell wall at the opening end of the shell 1 has sufficient thickness to ensure the structural strength of the shell 1 and meet the welding requirements of the cover plate 2 and the shell 1, thus avoiding problems such as weld line cracking.

[0022] Specifically, if b / a > 0.98, the length of the step structure 11 is too large, resulting in an excessively long area where the shell wall of the shell 1 needs to be thinned. This leads to poor structural strength of the shell 1 at the open end, making it prone to deformation or even breakage. Furthermore, the excessively long thinning area of ​​the shell wall of the shell 1 also results in poor welding strength between the cover plate 2 and the shell 1, leading to low welding quality, weld cracking, and assembly failure of the shell 1 and cover plate 2. If b / a < 0.02, the length of the step structure 11 is too small, resulting in insufficient limiting effect of the step structure 11 on the cover plate 2. This affects the assembly efficiency of the cover plate 2 and the shell 1 and easily causes misalignment between the cover plate 2 and the shell 1. Higher welding strength is required between the cover plate 2 and the shell 1 to ensure reliable connection. However, insufficient welding strength between the cover plate 2 and the shell 1 can also easily lead to assembly failure of the shell 1 and cover plate 2.

[0023] Optionally, b / a can be any value from 0.02, 0.04, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.94, 0.96, 0.98, or a value between any two values.

[0024] It is worth noting that in related technologies, thinning the shell wall along the two short sides in the width direction and / or the two long sides in the length direction at the opening end of the shell 1 to form a stepped structure 11 on the two short sides, or the two long sides, or the entire circumference, can lead to an excessively long thinned area of ​​the shell 1, resulting in problems such as low structural strength of the shell 1 and poor welding quality between the cover plate 2 and the shell 1. In this embodiment, by limiting the proportion of the length of the stepped structure 11 (i.e., the length of the thinned area) to the circumference of the shell 1, the thinned area has a suitable length on the shell 1. This allows for effective positioning of the cover plate 2 using the stepped structure 11 while ensuring the structural strength of the shell 1 and the welding quality between the cover plate 2 and the shell 1.

[0025] It should be noted that you should refer to [link / reference]. Figure 3 In the circumferential direction of the shell 1 around the opening, the circumference a of the shell 1 refers to the length around the inner wall of the shell 1, and the total length b of the stepped structure 11 refers to the total length of the inner edge of the stepped structure 11.

[0026] It should be noted that the step structure 11 can be provided as a single unit and continuously arranged along the circumference of the opening, or it can be provided at intervals along the circumference of the shell 1 around the opening. When the step structure 11 is provided as a single unit, the total length b of the step structure 11 is the length of the single step structure 11; when the step structure 11 is provided as a plurality of units, the total length b of the step structure 11 is the sum of the lengths of the plurality of step structures 11.

[0027] It should be further explained that when several stepped structures 11 are provided and spaced apart along the circumference of the opening, the distance between two adjacent stepped structures 11 is 40mm to 400mm. Specifically, if the distance between two adjacent stepped structures 11 is too small, the dispersion effect of several stepped structures 11 in the circumference of the opening is poor, that is, the positions of several stepped structures 11 are too concentrated, the limiting force provided by the stepped structures 11 to the cover plate 2 is too concentrated, and the limiting effect of the stepped structures 11 on the cover plate 2 is poor; if the distance between two adjacent stepped structures 11 is too large, it is impossible to provide limiting for the cover plate 2 within a large distance between the two adjacent stepped structures 11, the limiting effect of the stepped structures 11 on the cover plate 2 is insufficient, and the positional accuracy of the cover plate 2 assembled on the housing 1 is low.

[0028] Optionally, the distance between two adjacent step structures 11 can be any value or a value between any two of the following: 40mm, 50mm, 60mm, 70mm, 80mm, 90mm, 100mm, 110mm, 120mm, 130mm, 140mm, 150mm, 160mm, 170mm, 180mm, 190mm, 200mm, 210mm, 220mm, 230mm, 240mm, 250mm, 260mm, 270mm, 280mm, 290mm, 300mm, 310mm, 320mm, 330mm, 340mm, 350mm, 360mm, 370mm, 380mm, 390mm, and 400mm.

[0029] In one embodiment, the total length b of the step structure 11 satisfies 20mm ≤ b ≤ 240mm. This configuration ensures the positioning effect of the step structure 11 on the cover plate 2, thereby guaranteeing the assembly and welding quality of the cover plate 2 and the shell 1. At the same time, it ensures that the shell wall at the open end of the shell 1 has sufficient thickness to guarantee the structural strength of the shell 1 and meet the welding requirements of the cover plate 2 and the shell 1, thus avoiding problems such as weld cracking.

[0030] It is worth noting that if b > 240 mm, the length of the step structure 11 is too large, resulting in an excessively long area requiring thinning of the shell wall of the housing 1. This leads to poor structural strength of the housing 1 at the open end, making it prone to deformation or even breakage. Furthermore, the excessively long thinning area of ​​the shell wall also results in poor welding strength between the cover plate 2 and the housing 1, leading to lower welding quality, weld cracking, and assembly failure of the housing 1 and cover plate 2. If b < 20 mm, the length of the step structure 11 is too small, resulting in insufficient restraint of the cover plate 2, affecting the assembly efficiency of the cover plate 2 and housing 1, and easily causing misalignment. This necessitates higher welding strength between the cover plate 2 and housing 1 to ensure reliable connection. However, insufficient welding strength between the cover plate 2 and housing 1 can also easily lead to assembly failure. Therefore, by further limiting the value of b, the assembly and welding quality of the cover plate 2 and housing 1 can be further guaranteed.

[0031] Optionally, the value of b can be any value or a value between any two of the following: 20mm, 30mm, 40mm, 50mm, 60mm, 70mm, 80mm, 90mm, 100mm, 110mm, 120mm, 130mm, 140mm, 150mm, 160mm, 170mm, 180mm, 190mm, 200mm, 210mm, 220mm, 230mm, and 240mm.

[0032] In one embodiment, the perimeter 'a' of the housing 1 satisfies 200mm ≤ a ≤ 1000mm. This configuration facilitates the installation of the stepped structure 11 while ensuring the structural strength of the housing 1 meets the welding requirements of the cover plate 2 and the housing 1, thus avoiding problems such as weld cracking.

[0033] It is worth noting that if a > 1000 mm, the perimeter of the shell 1 is too large, which will make the volume of the cover plate 2 that mates with the shell 1 too large. In order to ensure the limiting effect of the cover plate 2, a step structure 11 with a long length is required to limit and support the cover plate 2. This results in an excessively long area of ​​thinning of the shell wall of the shell 1, which in turn leads to poor structural strength of the shell 1 at the opening end. The shell 1 is prone to deformation or even breakage at the opening end. At the same time, the excessively long thinning area of ​​the shell wall of the shell 1 will also lead to poor welding strength between the cover plate 2 and the shell 1, resulting in low welding quality and problems such as weld line cracking, causing assembly failure of the shell 1 and the cover plate 2. If a < 200 mm, the perimeter of the shell 1 is too small, and the volume of the cover plate 2 that mates with the shell 1 is small. In order to ensure the welding quality of the cover plate 2 and the shell 1, a thinning area with a short length, i.e., a step structure 11, can meet the limiting effect of the cover plate 2. However, it is not convenient to process and form a short step structure 11 on a shell 1 with a small perimeter.

[0034] Optionally, the value of 'a' can be any value or a value between any two of the following: 200mm, 240mm, 280mm, 300mm, 340mm, 380mm, 400mm, 440mm, 480mm, 500mm, 540mm, 580mm, 600mm, 640mm, 680mm, 700mm, 740mm, 780mm, 800mm, 840mm, 880mm, 900mm, 940mm, 980mm, and 1000mm.

[0035] In one embodiment, such as Figure 1 and Figure 3 As shown, the casing 1 has a quadrangular prism structure. Quadrilateral prism batteries are a commonly used battery structure, such as prismatic batteries and blade batteries. When quadrangular prism batteries are integrated, the batteries can be arranged more closely, resulting in higher space utilization and thus improving the energy density of the battery module.

[0036] Specifically, such as Figure 1 and Figure 3As shown, the housing 1 includes a first plate 15 and a second plate 16. Two first plates 15 and two second plates 16 are arranged at intervals relative to each other, and the first plates 15 and the second plates 16 are connected sequentially. When the housing 1 has an opening at only one end, the opening is formed by the first ends of the two first plates 15 and the two second plates 16 located on the same side. When both ends of the housing 1 have openings, one opening is formed by the first ends of the two first plates 15 and the two second plates 16 located on the same side, and another opening is formed by the second ends of the two first plates 15 and the two second plates 16 located on the same side. An angle 12 is formed at the connection point of adjacent first plates 15 and second plates 16. Further, a rounded corner structure can be formed at the angle 12, that is, the first plates 15 and the second plates 16 are connected by a rounded corner structure. Of course, the angle 12 can also be a right angle structure, that is, the first plates 15 and the second plates 16 are connected perpendicularly. Therefore, at least one of the first plate 15, the second plate 16 and the edge 12 is provided with a stepped structure 11, that is, the open end of the shell 1 has four sides and four edges 12, and the stepped structure 11 is provided corresponding to at least one side, or the stepped structure 11 is provided corresponding to at least one edge 12.

[0037] It is worth noting that, in this embodiment, for the quadrangular prism shell 1 with rounded corners 12, the circumference a of the shell 1 around the opening is the sum of the lengths of the two first plates 15 along the inner wall, the lengths of the two second plates 16 along the inner wall, and the arc lengths of the four rounded corner structures along the inner wall.

[0038] Specifically, in one embodiment, the opening end of the housing 1 has four corners 12, and the stepped structure 11 is provided corresponding to at least two corners 12, satisfying 0.04≤b / a≤0.98. This arrangement ensures the structural strength of the housing 1 while improving the positioning effect of the stepped structure 11 on the cover plate 2, thereby improving assembly efficiency and quality.

[0039] It is worth noting that the corners 12 of the quadrangular prism shell 1 have relatively high structural strength. Therefore, setting the stepped structure 11 corresponding to the corners 12 of the shell 1 has a relatively small impact on the overall structural strength of the shell 1. Furthermore, setting the length of the stepped structure 11 to be relatively long can also ensure the structural strength of the shell 1. Therefore, setting the stepped structure 11 corresponding to at least two corners 12 of the shell 1 and further limiting the range of b / a can not only ensure the structural strength of the shell 1 and avoid problems such as deformation and breakage of the shell 1 at the opening end, as well as weld cracking caused by poor welding quality between the cover plate 2 and the shell 1, but also improve the limiting effect of the stepped structure 11 on the cover plate 2, thereby improving the assembly efficiency of the cover plate 2 and the shell 1, and improving the positional accuracy of the cover plate 2 assembled on the shell 1, ensuring the welding reliability of the cover plate 2 and the shell 1, thereby improving the assembly quality of the cover plate 2 and the shell 1.

[0040] Furthermore, in one embodiment, the step structure 11 is disposed at two diagonally arranged corners 12, satisfying 0.04≤b / a≤0.96. The diagonally arranged step structure 11 limits the cover plate 2, making the limiting force on the step structure 11 more evenly distributed, thus providing better limiting effect on the cover plate 2. This further improves the positioning effect of the step structure 11 on the cover plate 2, thereby improving assembly efficiency and quality, while also ensuring the structural strength and welding quality of the shell 1.

[0041] It is worth noting that because the diagonally arranged stepped structure 11 provides better positioning for the cover plate 2, even with a relatively short length, the positioning effect on the cover plate 2 can still be guaranteed. Therefore, by arranging the stepped structure 11 diagonally opposite the two corners 12 of the shell 1 and further limiting the range of b / a, the positioning effect of the stepped structure 11 on the cover plate 2 can be guaranteed, thus ensuring the assembly efficiency of the cover plate 2 and the shell 1. Furthermore, it ensures the positional accuracy of the cover plate 2 within the shell 1, guarantees the welding reliability of the cover plate 2 and the shell 1, thereby improving the assembly quality of the cover plate 2 and the shell 1. It also further enhances the structural strength of the shell 1, preventing deformation and breakage at the opening end of the shell 1, as well as weld cracking caused by poor welding quality between the cover plate 2 and the shell 1.

[0042] Alternatively, as an alternative implementation, the stepped structure 11 is provided at each of the four corners 12, satisfying 0.04 ≤ b / a ≤ 0.94. With this configuration, the limiting force provided by the stepped structure 11 at each of the four corners 12 to the cover plate 2 is more uniform, resulting in a better limiting effect on the cover plate 2. Therefore, the length of the stepped structure 11 can be further shortened. That is, when the stepped structure 11 is provided at each of the four corners 12, further limiting the range of b / a, the limiting effect of the stepped structure 11 on the cover plate 2 is ensured, thereby guaranteeing the assembly efficiency of the cover plate 2 and the shell 1. Furthermore, it ensures the positional accuracy of the cover plate 2 assembled on the shell 1, guarantees the welding reliability of the cover plate 2 and the shell 1, and improves the assembly quality of the cover plate 2 and the shell 1. Simultaneously, it further enhances the structural strength of the shell 1, preventing problems such as deformation and breakage at the opening end of the shell 1, as well as weld cracking caused by poor welding quality between the cover plate 2 and the shell 1.

[0043] In one embodiment, such as Figure 2 , Figure 8 and Figure 9 As shown, the shell wall of the shell 1 forms a shell opening 13 at the open end. The shell 1 also includes a main body 14, which is connected to the side of the shell opening 13 away from the opening. A stepped structure 11 is formed on the side of the main body 14 facing the shell opening 13. That is, the shell wall of the shell opening 13 has a thinned area relative to the shell wall of the main body 14, and the portion of the shell wall of the main body 14 that extends beyond the thinned area of ​​the shell wall of the shell opening 13 forms the stepped structure 11.

[0044] It is worth noting that the shell opening 13 is used to accommodate the cover plate 2, and the main body 14 is used to accommodate the battery cell.

[0045] Specifically, in this embodiment, such as Figure 2 and Figure 4As shown, the main body 14 forms a first rounded corner 141 at the corner 12, and the shell opening 13 forms a second rounded corner 131 at the corner 12. The first rounded corner 141 and the second rounded corner 131 enclose and form a stepped structure 11. The radius of the first rounded corner 141 is r1, and the radius of the second rounded corner 131 is r2, satisfying r1≥r2. With this configuration, the stepped structure 11 formed by the first rounded corner 141 and the second rounded corner 131 is crescent-shaped. That is, the stepped structure 11 is wider at the middle position of the circumference of the shell 1 around the opening, which can provide a greater limiting force to the cover plate 2 and play a better limiting role in the cover plate 2, ensuring the positioning effect of the stepped structure 11 on the cover plate 2. Furthermore, since the corner 12 of the shell 1 has higher structural strength than the plates (first plate 15 and second plate 16) of the shell 1, and the width of the stepped structure 11 gradually decreases towards both ends of the circumference of the shell 1 around the opening, the influence of the stepped structure 11 on the structural strength of the shell 1 can be reduced, thereby ensuring the structural strength of the shell 1 and avoiding problems such as deformation and breakage of the shell 1 at the opening end, as well as weld cracking caused by poor welding quality between the cover plate 2 and the shell 1.

[0046] Furthermore, the radius r1 of the first fillet 141 satisfies 0.5mm≤r1≤5mm, and the radius r2 of the second fillet 131 satisfies 0.4mm≤r2≤4.8mm. This configuration ensures the positioning effect of the cover plate 2 while guaranteeing the structural strength of the shell 1 and meeting the welding requirements of the cover plate 2 and the shell 1, thus avoiding problems such as weld cracking.

[0047] It is worth noting that if the values ​​of r1 and r2 are too large, the width of the step structure 11 will be too small, and the limiting force provided by the step structure 11 to the cover plate 2 will be small, affecting the positioning effect of the step structure 11 on the cover plate 2. If the values ​​of r1 and r2 are too small, the thickness of the shell 1 will be reduced too much, which will affect the structural strength of the shell 1, and may lead to problems such as deformation and breakage of the shell 1 at the opening end, as well as cracking of the weld line caused by poor welding quality between the cover plate 2 and the shell 1.

[0048] Optionally, r1 can be any value or a value between any two of the following: 0.5mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.2mm, 2.5mm, 2.8mm, 3mm, 3.2mm, 3.5mm, 3.8mm, 4mm, 4.2mm, 4.5mm, 4.8mm, 5mm.

[0049] Optionally, r2 can be any value or a value between any two of the following: 0.4mm, 0.6mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.2mm, 2.5mm, 2.8mm, 3mm, 3.2mm, 3.5mm, 3.8mm, 4mm, 4.2mm, 4.5mm, and 4.8mm.

[0050] It is worth noting that the outer casing (including housing 1 and cover plate 2) is used to encapsulate components such as the battery cell and electrolyte. Housing 1 can be of various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. The shape of housing 1 can be determined according to the specific shape and size of the battery cell. The material of housing 1 can be various, including but not limited to copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0051] It should be further explained that the cover plate 2 refers to a component that covers the opening of the housing 1 to isolate the housing 1's accommodating space from the external environment. The shape of the cover plate 2 can be adapted to the shape of the housing 1 to fit the housing 1. The cover plate 2 can be made of a material with a certain degree of hardness and strength (such as aluminum alloy).

[0052] In one embodiment, both the housing 1 and the cover plate 2 are made of aluminum, satisfying 0.04≤b / a≤0.98.

[0053] It is worth noting that the aluminum cover plate 2 has a low hardness. To avoid the impact of deformation of the cover plate 2 during assembly, a longer step structure 11 is required to ensure the limiting effect on the aluminum cover plate 2. At the same time, for aluminum, the melting point of the shell 1 and the cover plate 2 is low, and the welding quality of the shell 1 and the cover plate 2 is good. Therefore, by further limiting the range of b / a, both the welding quality of the shell 1 and the cover plate 2 can be guaranteed, as well as the limiting effect of the step structure 11 on the cover plate 2. This improves the assembly efficiency of the cover plate 2 and the shell 1, and also improves the positional accuracy of the cover plate 2 assembled in the shell 1, ensuring the welding reliability of the cover plate 2 and the shell 1, thereby improving the assembly quality of the cover plate 2 and the shell 1.

[0054] In another embodiment, both the housing 1 and the cover plate 2 are made of steel, satisfying 0.02≤b / a≤0.96.

[0055] It is worth noting that, for steel, the shell 1 and cover plate 2 have high melting points, resulting in poor welding quality. Therefore, a thicker shell wall is needed to ensure welding quality. Simultaneously, the steel cover plate 2 has high hardness, making it less prone to deformation during assembly. Therefore, even a shorter step structure 11 can meet the limiting requirements for the steel cover plate 2. By further limiting the range of b / a, both the welding quality of the shell 1 and cover plate 2 and the limiting effect of the step structure 11 on cover plate 2 can be guaranteed, thereby improving the assembly efficiency of cover plate 2 and shell 1, enhancing the positional accuracy of cover plate 2 within shell 1, ensuring welding reliability of cover plate 2 and shell 1, and ultimately improving the overall assembly quality of cover plate 2 and shell 1.

[0056] In one embodiment, such as Figure 4 As shown, the maximum width between the inner edge and the outer edge of the step structure 11 is c, which satisfies 0.2mm≤c≤4mm. This configuration ensures the positioning effect of the step structure 11 on the cover plate 2, thereby guaranteeing the assembly and welding quality of the cover plate 2 and the shell 1. Simultaneously, it ensures that the shell wall at the opening end of the shell 1 has sufficient thickness to guarantee the structural strength of the shell 1 and meet the welding requirements of the cover plate 2 and the shell 1, avoiding problems such as weld cracking.

[0057] It is worth noting that if c > 4 mm, the width of the step structure 11 is too large, resulting in excessive thinning and insufficient remaining thickness of the shell 1. This leads to poor structural strength of the shell 1 at the opening end, making it prone to deformation or even breakage. Furthermore, an excessively long thinning area in the shell 1 also results in poor welding strength between the cover plate 2 and the shell 1, leading to low welding quality, weld cracking, and assembly failure of the shell 1 and cover plate 2. If c < 0.2 mm, the width of the step structure 11 is too small, resulting in insufficient limiting effect of the step structure 11 on the cover plate 2. This affects the assembly efficiency of the cover plate 2 and the shell 1 and easily causes misalignment between the cover plate 2 and the shell 1. Higher welding strength is required between the cover plate 2 and the shell 1 to ensure reliable connection. However, insufficient welding strength between the cover plate 2 and the shell 1 can also easily lead to assembly failure.

[0058] Optionally, the value of c can be any value or a value between any two of the following: 0.2mm, 0.5mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.2mm, 2.5mm, 2.8mm, 3mm, 3.2mm, 3.5mm, 3.8mm, and 4mm.

[0059] In one embodiment, such as Figure 8 and Figure 9As shown, the cover plate 2 is at least partially embedded in the housing 1 through the opening, and the side of the cover plate 2 facing the step structure 11 abuts against the step structure 11.

[0060] It is worth noting that in one implementation method, such as Figure 8 As shown, the cover plate 2 is flat and is completely contained within the shell opening 13. The inner surface of the cover plate 2 abuts against the stepped structure 11, and the outer surface of the cover plate 2 is substantially flush with the end face of the opening of the shell 1, thereby allowing welding to be performed at the joint between the outer surface of the cover plate 2 and the end face of the opening of the shell 1. In another embodiment, as... Figure 9 As shown, along the thickness direction of the cover plate 2, the cover plate 2 includes a covering portion 22 and an insert portion 21 connected together. The outer peripheral surface of the covering portion 22 extends beyond the outer peripheral surface of the insert portion 21, so that the outer peripheral surface of the cover plate 2 forms a stepped shape. The insert portion 21 is accommodated in the shell opening portion 13. The side of the insert portion 21 away from the covering portion 22 abuts against the stepped structure 11. The covering portion 22 is located outside the shell 1. Along the thickness direction of the cover plate 2, at the step, the side of the covering portion 22 near the insert portion 21 abuts against the end face of the opening end of the shell 1. The shell 1 and the cover plate 2 are welded along the outer periphery of the shell opening portion 13 and the outer periphery of the covering portion 22.

[0061] In one embodiment, such as Figure 7 As shown, the casing 1 and the cover plate 2 enclose a receiving space 3. The battery also includes a battery cell, which is disposed within the receiving space 3. The battery cell includes a cell body and a tab extending from the cell body. The cell body is located on the side of the stepped structure 11 away from the opening. This arrangement ensures that the cover plate 2 and the casing 1 can be smoothly assembled, avoiding interference between the cover plate 2 and the battery cell within the casing 1, which could damage the battery cell.

[0062] It is worth noting that the battery cell body is located on the side of the stepped structure 11 away from the opening, that is, on the orthographic projection along the first plate 15 (i.e. the large surface of the battery cell body), the projection of the battery cell body and the projection of the stepped structure 11 do not coincide.

[0063] It should be noted that a battery cell includes the cell body, which comprises a separator and two types of electrodes with opposite polarities: a positive electrode and a negative electrode. The cell operates by the movement of metal ions between the positive and negative electrodes. The cell's cycling process involves metal ions moving from the positive electrode to the negative electrode and then back again. The cell also includes tabs, which are electrically connected to the electrodes. The positive tab is electrically connected to the positive electrode, and the negative tab is electrically connected to the negative electrode. The cell charges and discharges through these tabs. Each electrode comprises a current collector and an active material layer, with the active material layer coated on the surface of the current collector. If the electrode is a positive electrode, the current collector can be made of aluminum, and the active material layer can be made of lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. If the electrode is a negative electrode, the current collector can be made of copper, and the active material layer can be made of carbon or silicon, etc. The separator acts as an insulating layer to prevent short circuits inside the battery caused by contact between the positive and negative electrodes. It also acts as a semi-permeable layer to prevent larger molecules from passing through while allowing smaller charged ions to pass through.

[0064] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A battery, characterized in that, include: The shell (1) is open at at least one end, and the shell wall of the shell (1) is thinned at the open end to form at least one stepped structure (11) inside the shell (1). A cover plate (2) is used to seal the opening and welded to the housing (1). The cover plate (2) is abutting against the stepped structure (11). Wherein, in the circumferential direction of the shell (1) surrounding the opening, the circumference of the shell (1) is a, and the total length of the stepped structure (11) is b, satisfying 0.02≤b / a≤0.98; The shell (1) is a quadrangular prism structure; The shell (1) has four corners (12) at its open end. The shell wall of the shell (1) forms a shell opening (13) at the opening end. The shell (1) also includes a main body (14), which is connected to the shell opening (13) on the side away from the opening. The stepped structure (11) is formed on the side of the main body (14) facing the shell opening (13). The main body (14) forms a first rounded corner (141) at the corner (12), and the shell opening (13) forms a second rounded corner (131) at the corner (12). At least one stepped structure (11) includes the first rounded corner (141) and the second rounded corner (131) enclosing to form the stepped structure (11).

2. The battery according to claim 1, characterized in that, The total length b of the stepped structure (11) satisfies 20mm≤b≤240mm.

3. The battery according to claim 1, characterized in that, The perimeter a of the shell (1) satisfies 200mm≤a≤1000mm.

4. The battery according to any one of claims 1 to 3, characterized in that, The shell (1) has four sides at its open end, and the stepped structure (11) is provided corresponding to at least one of the sides.

5. The battery according to any one of claims 1 to 3, characterized in that, The stepped structure (11) is provided with one and is continuously arranged along the circumference surrounding the opening.

6. The battery according to any one of claims 1 to 3, characterized in that, The stepped structure (11) is provided with a plurality of steps spaced apart along the circumference surrounding the opening.

7. The battery according to claim 6, characterized in that, The distance between two adjacent stepped structures (11) is 40mm to 400mm.

8. The battery according to any one of claims 1 to 3, characterized in that, The step structure (11) is provided for at least two of the edges (12) to satisfy 0.04≤b / a≤0.

98.

9. The battery according to claim 8, characterized in that, The step structure (11) is located at the two diagonally arranged edges (12), satisfying 0.04≤b / a≤0.

96.

10. The battery according to claim 8, characterized in that, The stepped structure (11) is set with respect to the four edges (12), satisfying 0.04≤b / a≤0.

94.

11. The battery according to claim 8, characterized in that, The radius of the first fillet (141) is r1, and the radius of the second fillet (131) is r2, satisfying r1≥r2.

12. The battery according to claim 11, characterized in that, The radius r1 of the first fillet (141) satisfies 0.5mm≤r1≤5mm, and the radius r2 of the second fillet (131) satisfies 0.4mm≤r2≤4.8mm.

13. The battery according to any one of claims 1 to 3, characterized in that, Both the housing (1) and the cover plate (2) are made of aluminum and satisfy 0.04≤b / a≤0.

98.

14. The battery according to any one of claims 1 to 3, characterized in that, Both the shell (1) and the cover plate (2) are made of steel and satisfy 0.02≤b / a≤0.

96.

15. The battery according to any one of claims 1 to 3, characterized in that, The maximum width between the inner edge and the outer edge of the step structure (11) is c, which satisfies 0.2mm≤c≤4mm.

16. The battery according to any one of claims 1 to 3, characterized in that, The cover plate (2) is at least partially embedded in the housing (1) through the opening, and the side of the cover plate (2) facing the step structure (11) abuts against the step structure (11).

17. The battery according to any one of claims 1 to 3, characterized in that, The housing (1) and the cover plate (2) enclose a receiving space (3). The battery also includes a cell, which is disposed in the receiving space (3). The cell includes a cell body and a tab extending from the cell body. The cell body is located on the side of the stepped structure (11) away from the opening.

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