Battery casing, battery, and electrical equipment

Abstract

This application provides a battery casing, a battery, and an electrical device. The battery casing includes a casing body and a cover plate, which are fixedly connected by a welded portion. The welded portion includes a first welded portion, which simultaneously connects at least the outer surfaces of the cover plate and the sidewall of the casing body. This improves the welding strength between the casing body and the cover plate, reduces the risk of separation between the casing body and the cover plate during battery use, and effectively reduces the occurrence of safety accidents such as battery leakage, thereby improving the battery's safety performance.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to battery casings, batteries, and electrical devices. Background Technology

[0002] With the increasing application of batteries in various fields, battery safety has become one of the most pressing concerns for battery manufacturers and consumers. Generally, a battery consists of a battery casing and the electrode core housed within the casing. The battery casing typically includes a housing and a cover plate. To ensure the safety of the battery during subsequent use, it is essential to ensure a secure connection between the cover plate and the housing housing.

[0003] Therefore, improving the connection between the cover plate and the casing body is a problem that urgently needs to be solved in the battery field. Summary of the Invention

[0004] In view of this, this application provides a battery housing, which includes a housing body and a cover plate. The housing body and the cover plate are fixedly connected by a welding part. The welding part includes a first welding part, which simultaneously connects at least multiple surfaces of the cover plate and the outer surface of the side wall of the housing body. This improves the welding strength between the housing body and the cover plate, reduces the risk of separation between the housing body and the cover plate during battery use, and thus effectively reduces the occurrence of safety accidents such as battery leakage, thereby improving the safety performance of the battery.

[0005] The first aspect of this application provides a battery housing, the battery housing including a cover plate and a housing body, wherein at least one end of the housing body has an opening along a first direction, and the cover plate is adapted to cover the opening of the housing body by a welded portion and form a receiving space;

[0006] The cover plate has a first surface and a second surface arranged opposite to each other, the first surface being the side surface of the cover plate facing away from the receiving space; the side wall of the shell body has a third surface and a fourth surface arranged opposite to each other, the third surface being the side surface of the shell body facing away from the receiving space.

[0007] The welding portion includes a first welding portion;

[0008] On a cross section of the battery casing perpendicular to a third direction, the intersection point of the first welded part and the first surface is A, and the intersection point of the first welded part and the third surface is B. The third direction is perpendicular to the first direction. The angle between the extension line of the outline of the third surface on the cross section and the line connecting points A and B is α, where 0 < α < 90°. The extension line extends from point B toward the plane containing the second surface and along the first direction.

[0009] Understandably, the cover plate has a certain thickness, and there is a sidewall connecting the first and second surfaces of the cover plate. In the battery casing, the angle α between the line AB and the extension of the outer contour line of the casing body satisfies 0 < α < 90°. Therefore, it is not difficult to deduce that the first welded part connects at least the cover plate and the third surface of the casing body (the outer surface of the sidewall of the casing body) at the same time, which improves the welding strength between the casing body and the cover plate. This can reduce the risk of separation between the casing body and the cover plate during battery use, thereby effectively reducing the occurrence of safety accidents such as battery leakage and improving the safety performance of the battery.

[0010] Optionally, 30°≤α≤60°.

[0011] Optionally, the distance from point B to the plane containing the first surface of the cover plate is W1, the distance from point A to the second surface is W2, and the distance from point B to the fourth surface is W3; the first welded part satisfies: 0.2W3≤(W1-W2)×tanα≤W3; W1, W2, and W3 are in the same unit.

[0012] Furthermore, in the direction toward the receiving space, the outer edge of the first welded portion does not exceed the second surface and the fourth surface.

[0013] Optionally, the orthographic projection of point A onto the second surface is point A', and point A' is located within the orthographic projection of the shell body onto the cover plate or on its boundary.

[0014] Optionally, along the second direction and the third direction, the orthographic projection of the cover plate does not overlap with the orthographic projection of the shell body, and the first direction, the second direction and the third direction are perpendicular to each other.

[0015] Optionally, in the first direction, there is a gap between the shell body and the cover plate; the width of the gap is L1, 0. <L1≤0.05mm。

[0016] Optionally, the first weld portion protrudes relative to the first surface and / or the third surface, and the maximum protrusion of the first weld portion relative to the first surface is L2; ​​the maximum protrusion of the first weld portion relative to the third surface is L3; <L2≤0.05mm;0<L3≤0.05mm。

[0017] Optionally, the distance from point A to the second surface is W2, and the distance from point B to the fourth surface is W3, where 0.05mm ≤ W2 ≤ W3. Further, W2 < W3, and 30° ≤ α ≤ 45°.

[0018] Optionally, along the first direction, the two ends of the shell body have openings, and the battery shell includes two cover plates; wherein, the second surface is the surface with the largest surface area of ​​the battery shell.

[0019] A second aspect of this application provides a battery, including the battery casing and electrode core provided in the first aspect of this application; wherein the electrode core is housed within the receiving space of the battery casing. Because this battery uses the battery casing provided in this application, it is less prone to safety accidents such as battery leakage, and the battery has high safety performance.

[0020] A third aspect of this application provides an electrical device that includes the battery provided in the second aspect of this application. Because the device uses the aforementioned battery to power it, it has good market competitiveness. Attached Figure Description

[0021] Figure 1A This is an exploded view of one structure of the battery described in this application;

[0022] Figure 1B yes Figure 1A Top view of the battery;

[0023] Figure 1C yes Figure 1B Cross-sectional view at point DD;

[0024] Figure 2 yes Figure 1C A magnified view of part b in the middle;

[0025] Figure 3A yes Figure 1C A magnified view of part a in the middle;

[0026] Figure 3B yes Figure 1C A magnified view of part a, with dimensions and... Figure 3A different;

[0027] Figure 4 This is a magnified view of part a of the battery in Comparative Example 1;

[0028] Figure 5 This is an exploded view of another structure of the battery casing in this application.

[0029] Reference numerals: 100-Battery; 10-Battery casing; 11-Cover plate; 111-First surface; 112-Second surface; 12-Casing body; 123-Third surface; 124-Fourth surface; 13-First welded part; 20-Polygonal core; 40-Sealing assembly; 41-Sealing cap; 42-Sealing plug; 50-Polygonal post assembly; 51-First tab; 52-Second tab; 60-Explosion-proof. Detailed Implementation

[0030] Generally, a battery consists of a battery casing and electrode cores housed within the casing. Taking a prismatic battery as an example, the battery casing includes a casing body and a cover plate. In some cases, the battery casing includes a casing body, an upper cover, and a lower cover. The casing body also houses electrode post assemblies, sealing assemblies, etc. The sealing assemblies seal the electrolyte injection holes on the casing body, which are used to inject electrolyte into the battery. The cover plate and casing body are generally fixed together by welding, often using laser welding. However, in current welding methods used by battery manufacturers, the laser is typically irradiated perpendicularly to the upper surface of the cover plate, causing partial melting of the cover plate and casing body, forming a welded section that penetrates the cover plate and extends into the casing body. This welded section only connects the upper surfaces of the cover plate and the casing body's sidewalls. Batteries produced using this welding method are not robust enough and cannot guarantee battery safety during subsequent use; especially after a drop or impact, the welded section is prone to failure, leading to electrolyte leakage and other adverse consequences, potentially causing safety accidents.

[0031] To address the aforementioned problems, this application provides a battery casing 10, which can be found in conjunction with the above. Figures 1A-3B The battery casing 10 includes a cover plate 11 and a casing body 12. Along a first direction, at least one end of the casing body 12 has an opening. The cover plate 11 is adapted to cover the opening of the casing body 12 through a welded portion and form a receiving space. Specifically, in the first direction, the casing body 12 may have an opening at one end and a sealed integral structure at the other end; in this case, the battery casing 10 includes a cover plate 11 and a casing body 12. Alternatively, the casing body 12 may have openings at both opposite ends in the first direction, and both openings are welded with cover plates 11 to achieve a sealed receiving space; in this case, the battery casing 10 includes an upper cover, a casing body 12, and a lower cover. It should be noted that when the casing body 12 has two oppositely arranged openings along the first direction, the sidewall of the casing body 12 is the casing body 12 itself.

[0032] The cover plate 11 has a first surface 111 and a second surface 112 disposed opposite to each other. The first surface 111 is the side surface of the cover plate 11 that is away from the receiving space. Understandably, the cover plate 11 has a certain thickness. Therefore, the cover plate 11 has a first surface 111, a second surface 112, and a sidewall located between the first surface 111 and the second surface 112 and connecting the first surface 111 and the second surface 112. The first surface 111 is the surface of the cover plate 11 that is away from the receiving space (the upper surface of the cover plate 11), and the second surface 112 is the surface of the cover plate 11 that faces the receiving space (the lower surface of the cover plate 11). The sidewall of the shell body 12 has a third surface 123 and a fourth surface 124 disposed opposite to each other (that is, the third surface 123 and the fourth surface 124 of the shell body 12). The third surface 123 is the side surface of the sidewall of the shell body 12 that is away from the receiving space. In this application, the shape of the battery casing 10 is not limited. In application, in order to adapt to different battery 100 shapes, the battery casing 10 may also have different shapes, such as square, cylindrical, irregular, etc. The shape of the cover plate 11 can be adapted to the shape of the opening of the casing body 12. Taking the battery casing 10 as a square as an example below, regardless of the above situation, the third surface 123 mentioned above refers to the outer surface of the casing body 12, and the fourth surface 124 mentioned above refers to the inner surface of the casing body 12.

[0033] The aforementioned welded portion includes the first welded portion 13. See also... Figure 3AA second direction and a third direction are defined, both perpendicular to the first direction, and the second direction and the third direction are mutually perpendicular. On the cross-section of the battery casing perpendicular to the third direction, the intersection point A of the first welded portion 13 and the first surface 111, and the intersection point B of the first welded portion 13 and the third surface 123 are defined. In some embodiments, the battery casing 10 is a square battery casing. It can be understood that the first direction is the extension direction (thickness direction) of the battery casing 10, the second direction is parallel to the length direction of the battery casing 10, and the third direction is parallel to the width direction of the battery casing 10; or, the second direction is parallel to the width direction of the battery casing 10, and the third direction is parallel to the length direction of the battery casing 10. In other embodiments, the battery casing 10 is cylindrical, the first direction is the extension direction (thickness direction) of the battery casing 10, and the second and third directions are respectively parallel to two mutually perpendicular diameters of its circular cover plate. Other shapes of battery casings 10 are adapted according to the above principles, and will not be elaborated here. In the aforementioned cross-section, the third surface 123 has a contour line (i.e., the outer contour line of the sidewall of the shell body 12 on the aforementioned cross-section), the line connecting points A and B is line AB, and the angle between the extension of the aforementioned contour line and line AB is α, 0 < α < 90°; wherein, the aforementioned extension line is the extension of the aforementioned contour line along the first direction from point B toward the plane containing the second surface 112. In this application, the aforementioned extension line can refer to a ray with point B as its endpoint, and the aforementioned angle is the intersection of line segment AB and the aforementioned ray. In other words, as... Figure 3A As shown, the effective area of ​​the first welding part 13 includes the upper surface (first surface 111) of the cover plate 11, the side wall of the cover plate 11, and the outer surface (third surface 123) of the side wall of the shell body 12. It can also act on the second surface 112 of the cover plate 11 and the upper surface of the side wall of the shell body 12, thereby improving the welding strength between the shell body 12 and the cover plate 11. This can reduce the risk of separation between the shell body 12 and the cover plate 11 during the use of the battery 100, and thus effectively reduce the occurrence of safety accidents such as battery leakage, and improve the safety performance of the battery 100.

[0034] In addition, the aforementioned first welded part 13 improves the welding strength between the shell body 12 and the cover plate 11, and also helps to improve the sealing performance of the battery 100.

[0035] In this application, for the fixed connection area between the cover plate 11 and the shell body 12, the entire fixed connection area between the cover plate 11 and the shell body 12 may be connected by the first welding part 13; alternatively, a portion of the connection area between the cover plate 11 and the shell body 12 may be connected by the first welding part 13, while the remaining fixed connection areas may be connected by an existing welding method (for ease of description, the welding part formed by the existing welding method is called the second welding part, which is not shown in the figure; that is, in some embodiments, the welding part includes the first welding part 13 and the second welding part). In some embodiments of this application, the battery casing 10 is square, that is, the outer contour of the cover plate 11 and the contour shape of the opening of the shell body 12 are both rectangular, and at least the four corners of the cover plate 11 and the shell body 12 have the first welding part 13. In some embodiments of this application, the battery casing 10 is cylindrical, that is, the outer contour of the cover plate 11 and the contour shape of the opening of the shell body 12 are both circular, elliptical, or nearly circular, and at least the rounded corners of the cover plate 11 and the shell body 12 have the first welding part 13. In some embodiments of this application, the shell body 12 and the cover plate 11 are completely connected and fixed by a first weld 13. That is, the contact area between the shell body 12 and the cover plate 11 has a first weld 13, which is more conducive to improving the robustness and sealing performance of the battery shell 10, and further ensuring the safety performance of the battery 100.

[0036] In this application, the aforementioned α can be 1°, 2°, 5°, 8°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, 42°, 45°, 48°, 50°, 52°, 55°, 58°, 60°, 62°, 65°, 68°, 70°, 75°, 80°, 85°, 88°, 89°, etc.

[0037] In this application, when describing the relationship between points A and B, it refers to the relationship between point B and point A on the corresponding cover plate 11. Specifically, when the battery casing 10 has both an upper cover and a lower cover, when discussing the relationship between points A and B, point A refers to point A of the upper cover, and point B is the intersection of the first welded part 13 connecting the upper cover and the shell body 12 and the third surface 123; the lower cover is similar, and will not be described again here. In addition, taking the square battery casing 10 as an example, the third surface 123 and the fourth surface 124 of the side wall of the shell body 12 both include four circumferentially arranged side surfaces. When discussing the relationship between points A and B and the third surface 123 and the fourth surface 124 in this application, the third surface 123 and the fourth surface 124 respectively refer to the two side surfaces corresponding to point B. Specifically, when discussing the relationship between points A and B, "third surface 123" refers to the side surface M where point B is located corresponding to point A, and "fourth surface 124" refers to the side surface N that is arranged opposite to the aforementioned side surface M. Other battery casings 10 are analogous to the above principles and will not be described in detail here.

[0038] In this application, the shape of the first welding portion 13 can be arbitrary. Understandably, in the above cross-section, the cross-sectional shape of the first welding portion 13 can also be arbitrary. For example, it can be bow-shaped, an irregular shape, etc. This application limits the relationship between the connecting line AB and the contour line of the third surface 123 in the above cross-section, but does not limit the relationship between the interface of the first welding portion 13 facing the connecting line AB and the contour line of the third surface 123 in the above cross-section. In the above cross-section, the contour line of the cross-section of the first welding portion 13 facing the connecting line AB can be irregular. It can be a straight line, a curve, a wavy line, etc. The contour line can protrude towards the accommodation space relative to the connecting line AB, can be concave relative to the connecting line AB, or can coincide or partially coincide with the connecting line AB.

[0039] In some embodiments of this application, in the first direction, there is a gap between the housing body 12 and the cover plate 11; the width of the gap is L1, and 0 < L1 ≤ 0.05 mm. Generally, due to reasons such as manufacturing precision, there will be the above-mentioned gap between the housing body 12 and the cover plate 11. Controlling L1 within the above range is beneficial for welding between the housing body 12 and the cover plate 11. At the same time, it can avoid damaging the electrode core 20 during the welding process. It should be noted that the accommodation space in this application refers to the space for accommodating the electrode core, and the accommodation space does not include the gap between the housing body 12 and the cover plate 11.

[0040] In some embodiments of this application, 30° ≤ α ≤ 60°. Exemplarily, α can be 30°, 32°, 35°, 38°, 40°, 42°, 45°, 48°, 50°, 52°, 55°, 58°, 60°, etc. The distance from point A to the plane of the third surface 123 where the corresponding point B is located (that is, the distance between point A and the extension line of the contour line of the third surface 123 in the above cross-section, where the extension line extends from point B towards the plane of the second surface 112 in the first direction) is H1, and the distance from point B to the plane of the corresponding first surface 111 is W1. Understandably, controlling α within the above range, the values of the above H1 and W1 are more appropriate; in other words, the first welding portion 13 is formed by welding the cover plate 11 and the housing body 12. Then, when α is within the above range, the area of the action region of the first welding portion 13 on the cover plate 11 and the housing body 12 is more appropriate, thereby further improving the firmness of the cover plate 11 and the housing body 12 after welding, and further facilitating the improvement of the safety performance of the battery 100.

[0041] Please refer to Figure 3AIn some embodiments of this application, the distance from point B to the plane containing the first surface 111 of the corresponding cover plate 11 is W1, the distance from point A to the second surface 112 is W2, and the distance from point B to the fourth surface 124 is W3; the first welded part 13 satisfies: 0.2W3≤(W1-W2)×tanα≤W3; W1, W2, and W3 are in the same unit. (W1-W2)×tanα≥0.2W3, the distance from the intersection point C of the first welded part 13 and the second surface 112 of the cover plate 11 to the plane of the corresponding third surface 123 is relatively large; in other words, considering the state of the cover plate 11 and the shell body 12 before welding, the welding size and welding area of ​​the upper surface of the side wall of the cover plate 11 and the shell body 12 before welding (the upper surface is the surface of the side wall of the shell body 12 before welding that is close to the cover plate 11, and the upper surface connects the third surface 123 and the fourth surface 124 of the shell body 12) are relatively large, so the connection between the cover plate 11 and the shell body 12 is more solid after welding; (W1-W2)×tanα≤W3, that is, the orthographic projection of the above point C on the shell body 12 falls in the side wall of the shell body 12, or coincides with the fourth surface 124; in this way, it will not affect the solidity of the cover plate 11 and the shell body 12, and it is easier to manufacture, and the electrode core 20 will not be damaged during the welding process.

[0042] Furthermore, in some specific embodiments of this application, the outer edge of the first welded portion 13 does not exceed the second surface 112 and the fourth surface 124 in the direction towards the receiving space. That is, in the direction towards the receiving space, the first welded portion 13 does not exceed the cover plate 11 and the shell body 12. It is emphasized again here that the receiving space in this application does not include the gap between the cover plate 11 and the shell body 12. In this way, no protruding part will compress the volume of the receiving space, thereby preventing compression of the space of the electrode core 20; at the same time, the inner surface of the battery casing 10 is a smooth surface, and no protruding material will threaten the safety of the electrode core 20; furthermore, during the welding process of the battery casing 10, no molten material / solder will fall onto the electrode core 20, providing all-round protection for the safety of the electrode core 20.

[0043] In some embodiments of the present application, the distance from point A to the second surface 112 is W2, and the distance from point B to the fourth surface 124 is W3, where 0.05 mm ≤ W2 ≤ W3. By controlling the thickness of W2 and W3 within the above range, it is possible to ensure that both the cover plate 11 and the battery housing 10 have a certain strength, provide protection for the electrode core 20 in the accommodation space, and reduce the risk of the cover plate 11 bending during welding and subsequent assembly processes, which is beneficial to the assembly of the battery 100. In some specific embodiments of the present application, 0.05 mm ≤ W2 ≤ 0.5 mm; 0.05 mm ≤ W3 ≤ 0.5 mm. Exemplarily, W2 and W3 can be independently 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.48 mm, etc. In some specific embodiments of the present application, 0.05 mm ≤ W2 < W3 ≤ 0.5 mm. Thus, on the premise of a certain size of the battery 100, the structural strength of the battery housing 10 can be ensured while reducing the space occupied by the cover plate, so that the battery housing 10 can provide more accommodation space to accommodate a larger volume of electrode core, thereby further improving the energy density of the battery 100.

[0044] In some embodiments of the present application, W2 < W3, and 30° ≤ α ≤ 45°. Exemplarily, at this time, α can be 30°, 31°, 32°, 33°, 34°, 35°, 36°, 37°, 38°, 39°, 40°, 41°, 42°, 43°, 44°, 45°, etc. In this way, H1 ≤ W1 and the difference between H1 and W1 is small. That is, the force exerted by the first welding part 13 on the cover plate 11 and the housing body 12 is more evenly distributed or biased towards the housing body 12. When the battery 100 is subjected to an external force impact from any direction, the stress transmission of the first welding part 13 to the cover plate 11 and the housing body 12 is equivalent, or more is transmitted to the housing body 12, giving full play to the bonding force of the housing body 12 on the first welding part 13, and further reducing the risk of cracks or even separation between the first welding part 13 and the cover plate 11 and the housing body 12. In addition, by controlling α within the above range, the influence of the welding heat on the cover plate 11 during the welding process of the battery housing 10 is small, which can fully reduce the risk of deformation of the cover plate 11, so that it is easier to obtain a battery housing 10 with better comprehensive performance and a higher yield rate.

[0045] In some embodiments of the present application, the orthographic projection of point A on the second surface is point A', and point A' is located inside or on the boundary of the orthographic projection of the housing body 12 on the cover plate 11. Combined with Figure 3BIn layman's terms, this can be understood as point A not exceeding the plane containing the fourth surface 124; or, the distance from point A to the plane containing the corresponding point B, the third surface 123, is H1, where H1 ≤ W3. In this way, defects such as pores will not appear on the cover plate 11, ensuring the sealing of the battery 100 and the robustness of the cover plate 11; simultaneously, during the manufacturing process, the cover plate 11 will not be welded through, and no molten material will fall from the cover plate 11 onto the electrode core 20.

[0046] In some embodiments of this application, the orthographic projection of the cover plate does not overlap with the orthographic projection of the shell body along the second direction and the third direction. It is understood that, to achieve the above structure, in the second direction and the third direction, the outer edge of the sidewall of the cover plate 11 before welding coincides with the third surface 123 of the shell body 12 before welding, or the outer edge of the sidewall of the cover plate 11 before welding extends beyond the third surface 123 of the shell body 12 before welding. This is more conducive to the positioning between the cover plate 11 and the shell body 12, and the first weld 13 can more firmly connect the cover plate 11 and the shell body 12.

[0047] In some embodiments of this application, the shell body 12 has openings at both ends along a first direction, and the battery casing 10 includes two cover plates 11; wherein, the surface of the cover plate 11 facing the receiving space (i.e., the second surface 112) is the surface with the largest surface area in the battery casing 10 (e.g., ...). Figure 1A (Structure shown). The second surface 112 has the largest surface area of ​​the battery housing 10. In other words, the cover plate 11 occupies the largest area in the battery housing 10, and the large opening area is more conducive to the subsequent assembly of the electrode core, improving production efficiency. In addition, due to structural characteristics, the thickness of the cover plate can be thinner than that of the housing body. Therefore, the second surface 112 is not the surface with the largest surface area of ​​the battery housing 10 (see [link to diagram]). Figure 5 In the case of the structure of the battery casing 10 shown, when the second surface 112 is the largest surface, the overall volume of the battery casing 10 can be smaller, which can improve the space utilization of the battery 100. Furthermore, in the current manufacturing process, the casing body 12 (especially the casing body 12 of a square battery casing) needs to be bent and then welded together. Reducing the size of the casing body 12 can reduce the size of the aforementioned sheet metal, making the bending process easier and thus facilitating the preparation of the casing body 12 itself.

[0048] In some embodiments of the present application, the first welding portion 13 protrudes relative to the first surface 111 and / or the third surface 123. The maximum dimension of the first welding portion 13 protruding relative to the first surface 111 is L2; the maximum dimension of the first welding portion 13 protruding relative to the third surface 123 is L3; 0 < L2 ≤ 0.05 mm; 0 < L3 ≤ 0.05 mm. Exemplarily, the above L2 and L3 can be independently 0.01 mm, 0.02 mm, 0.03 mm, 0.04 mm, 0.05 mm, etc. Controlling L2 and L3 within the above range can greatly save the external space of the battery 100 occupied by the first welding portion 13, facilitate the assembly of the battery 100, improve the space utilization rate of the battery 100, and at the same time ensure the connection firmness between the housing body 12 and the cover plate 11.

[0049] In some embodiments of the present application, the outer edges of the first welding portion 13 are flush with the first surface 111 and the third surface 123 respectively.

[0050] In some embodiments of the present application, the material of the battery housing 10 is selected from metals. In some specific embodiments, the materials of the cover plate 11 and the housing body 12 are independently selected from but not limited to stainless steel, elemental aluminum, aluminum alloy, etc.

[0051] In some embodiments of the present application, an explosion-proof mark 60 is further provided on the cover plate 11. When the internal pressure of the battery 100 is too high, since the thickness at the explosion-proof mark 60 is smaller than the thickness at other positions on the cover plate 11, when the internal pressure of the battery 100 is too high, the explosion-proof mark 60 will rupture and discharge the gas inside the battery 100 outward to achieve the purpose of pressure relief. This can prevent the battery 100 from exploding and improve the safety of the battery 100. In the present application, when the battery housing 10 has both an upper cover and a lower cover, the above explosion-proof mark 60 can be provided on the upper cover, or on the lower cover, or both the upper cover and the lower cover can be provided with the explosion-proof mark 60.

[0052] In some embodiments of this application, a terminal assembly 50 is provided on the shell body 12 (or the side wall of the shell body 12). Specifically, a first through hole is formed on the shell body 12 (or the side wall of the shell body 12), and the terminal assembly 50 is disposed at the first through hole. The terminal assembly 50 is insulated from the shell body 12. The terminal assembly 50 includes a terminal, a first insulating member, a second insulating member, and a metal sheet. The first insulating member, the second insulating member, and the metal sheet are all provided with through holes. The through holes on the first insulating member, the second insulating member, and the metal sheet are concentrically arranged with the first through hole on the shell body 12. The terminal can pass through the first insulating member, the shell body 12, the second insulating member, and the metal sheet sequentially from the outside to the inside. The other end of the terminal can be riveted to the metal sheet by compression to make an electrical connection between the terminal and the metal sheet. The first insulating member is sandwiched between the terminal and the shell body 12, and the second insulating member is sandwiched between the shell body 12 and the metal sheet. This arrangement can prevent the terminal from contacting the shell body 12 and causing a short circuit in the battery 100. It should be noted that the pole assembly 50 can also be set on the upper or lower cover, and there is no restriction here.

[0053] like Figures 1A-1C As shown, the battery 100 includes an electrode core 20, which includes an electrode core body and a first electrode tab 51 and a second electrode tab 52 extending from the electrode core body. The first electrode tab 51 and the second electrode tab 52 have opposite electrical polarities. That is, the first electrode tab 51 can be positive and the second electrode tab 52 can be negative; or, the first electrode tab 51 can be negative and the second electrode tab 52 can be positive. The first electrode tab 51 can be electrically connected to the terminal assembly 50, and the second electrode tab 52 can be electrically connected to the battery casing 10. The first electrode tab 51 can be electrically connected to a metal sheet, that is, the first electrode tab 51 is electrically connected to the terminal through a metal sheet to lead out the electrode. This design can increase the area of ​​the connectable region between the first electrode tab 51 and the terminal assembly 50, facilitating the electrical connection between the two. Specifically, the first electrode tab 51 and the terminal assembly 50 can be electrically connected by welding, bonding, or abutting.

[0054] It should be noted that the first tab 51 can be a tab group, meaning the first tab 51 can include at least two tabs. It can be obtained by stacking and then gathering multiple tabs together; or by gathering multiple tabs together and then welding them to an adapter plate. Similarly, the second tab 52 can also be a tab group, meaning the second tab 52 can include at least two tabs. It can be obtained by stacking and then gathering multiple tabs together; or by gathering multiple tabs together and then welding them to an adapter plate. This improves the rate performance of the battery 100.

[0055] It should be noted that insulating tape can also be pasted on both sides of the first tab 51. In the first direction of the battery 100, the tape can be pasted on the upper and lower sides of the first tab 51. This can prevent the first tab 51 from contacting the battery casing 10 and causing the battery 100 to short circuit.

[0056] The casing 12 also has an injection hole for injecting electrolyte into the battery 100. After the battery 100 is filled with electrolyte, the injection hole can be sealed with a sealing assembly 40. The sealing assembly 40 includes a sealing plug 42 and a sealing cap 41. After the electrolyte is filled, the sealing plug 42 is first inserted into the injection hole, and then the sealing cap 41 is pressed onto the sealing plug 42 and fixed to the casing 12 to seal the injection hole. The sealing plug 42 and the injection hole can be an interference fit. When the sealing cap 41 is pressed onto the sealing plug 42, the sealing plug 42 will be squeezed. This design can improve the sealing performance of the battery 100. Specifically, the sealing cap 41 and the casing 12 can be fixedly connected by welding. It should be noted that the injection hole can be located between the first tab 51 and the second tab 52, which is more conducive to injecting electrolyte into the battery 100 and can improve the wetting rate of the electrode core 20. It should be noted that the injection hole can also be located on the top or bottom cover. This application does not impose any restrictions and the design can be made according to specific needs.

[0057] This application embodiment also provides a battery 100, including a battery casing 10 and an electrode core 20 provided in this application embodiment; wherein the electrode core 20 is housed in the receiving space of the battery casing 10.

[0058] Because the battery 100 uses the battery casing 10 provided in this application, the battery 100 is less prone to safety accidents such as battery leakage, and the battery 100 has high safety performance.

[0059] This application also provides an electrical device, including the battery 100 provided in this application embodiment. Because the electrical device is powered by the aforementioned battery 100, the risk of safety accidents such as battery leakage during use is low, and its safety performance is high. Therefore, this electrical device has high market competitiveness.

[0060] In some embodiments of this application, the aforementioned electrical equipment includes, but is not limited to, vehicles, 3C electronic devices, etc.

[0061] The technical solution of this application will be further described in detail below with reference to several embodiments.

[0062] Example 1

[0063] A square battery S1 is provided, comprising a square battery casing and an electrode core housed within the battery casing. Along a first direction, the battery casing includes a cover plate and a casing body with an opening at one end. The cover plate covers the opening of the casing body through a first welded portion, forming a receiving space. For the battery S1, on a cross-section of the battery casing perpendicular to a third direction (denoted as the first direction being the extension direction of the battery casing, the third direction being perpendicular to the first direction and parallel to the length direction of the square battery casing), the intersection point A of the first welded portion and the first surface of the cover plate is denoted as A, and the intersection point B of the first welded portion and the third surface of the casing body is denoted as B. The angle between the extension line of the contour line of the third surface on the aforementioned cross-section (this extension line extends from point B towards the plane containing the second surface and along the first direction) and the line connecting points A and B is α, where α = 5°. Furthermore, towards the receiving space, the outer edge of the first welded portion almost coincides with the line AB.

[0064] Specifically, the distance W1 from point B to the plane containing the first surface of the cover plate is 0.15 mm, the distance W2 from point A to the second surface of the cover plate is 0.065 mm, and the distance W3 from point B to the fourth surface of the shell body is 0.22 mm. Meanwhile, the thickness of the cover plate is 0.065 mm, and the thickness of the sidewall of the shell body is 0.22 mm.

[0065] Example 2

[0066] The only difference from Example 1 is that α = 15°.

[0067] Example 3

[0068] The only difference from Example 1 is that α = 25°.

[0069] Example 4

[0070] The only difference from Example 1 is that α = 35°.

[0071] Example 5

[0072] The only difference from Example 1 is that α = 45°.

[0073] Example 6

[0074] The only difference from Example 1 is that α = 55°.

[0075] Example 7

[0076] The only difference from Example 1 is that α = 65°.

[0077] Example 8

[0078] The only difference from Example 1 is that α = 75°.

[0079] Example 9

[0080] The only difference from Example 1 is that α = 85°.

[0081] Example 10

[0082] The difference from Example 1 is that α = 45° and W1 is 0.09 mm.

[0083] Example 11

[0084] The difference from Example 1 is that α = 45° and W1 is 0.25 mm.

[0085] Example 12

[0086] The difference from Example 1 is that α = 45°, W1 is 0.15 mm, W2 is 0.05 mm, and W3 is 0.1 mm. Additionally, the cover plate thickness is 0.05 mm, and the shell body sidewall thickness is 0.1 mm.

[0087] Example 13

[0088] The difference from Example 1 is that α = 45°, W1 is 0.3 mm, W2 is 0.15 mm, and W3 is 0.5 mm. Additionally, the cover plate thickness is 0.15 mm, and the shell body sidewall thickness is 0.5 mm.

[0089] Example 14

[0090] The difference from Example 1 is that α = 35°, W1 is 0.15 mm, W2 is 0.065 mm, and W3 is 0.065 mm. Additionally, the cover plate thickness is 0.065 mm, and the thickness of the shell body sidewall is 0.065 mm.

[0091] To highlight the beneficial effects of this application, the following comparative examples are provided.

[0092] Comparative Example 1

[0093] A casing body and a cover plate are provided. The thickness parameters of the casing body and the cover plate are the same as in Example 1. The cover plate and the casing body are connected by a welded joint. For the cross-section of the battery, please refer to Example 1. Figure 4 .

[0094] Performance testing:

[0095] Tensile test: The strength of the weld between the cover plate and the casing body is determined by testing the maximum tensile force that the weld joint can withstand. Specifically, a tensile testing machine with an appropriate range is selected to test the battery casing.

[0096] First, the batteries of each embodiment and comparative example were disassembled, and the battery casings were cut into strips of the same size for testing. The width of each test sample was 0.5 cm, the cover plate was 2.5 cm long, and the casing body was 0.4 cm long. The battery casing test strips were fixed to the clamps of a tensile testing machine (YH-9002). The clamps held the casing body end and the cover plate end of the test strip, respectively; specifically, one end of the clamp held the casing body, and the other end held the cover plate. A tensile force was applied to the test sample, causing the clamps to move at a speed of 200 mm / min, until the weld between the cover plate and the casing body broke. The maximum tensile force during this test was recorded as the test result to obtain the maximum tensile force that the weld between the cover plate and the casing body could withstand. The larger this value, the stronger the weld between the cover plate and the casing body.

[0097] Five samples of the battery casing for the same embodiment / comparative example were prepared, and the average value was calculated. The results are summarized in Table 1.

[0098] Table 1

[0099]

[0100]

[0101] As can be seen from the results in Table 1, the maximum tensile force between the cover plate and the shell body of the battery body in this embodiment is significantly higher than that of the comparative battery, which fully demonstrates that the first welded part can significantly improve the firmness of the connection between the cover plate and the shell body.

[0102] Comparing the results of Examples 1-9, it can be seen that when α is controlled within the range of 30° to 60°, the robustness between the cover plate and the shell body is better; furthermore, when W2 < W3, the robustness between the cover plate and the shell body is even better when α is controlled within the range of 30° to 45° (Examples 4 and 5). Comparing the data of Example 5 with Examples 10-12, it can be seen that when α is the same, when (W1-W2)×tanα and W1×tanα(H1) further satisfy the conditions of this application, the welding strength between the cover plate and the shell body is higher.

[0103] In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise expressly and specifically limited.

[0104] The above description is an exemplary embodiment of this application. It should be noted that those skilled in the art can make several improvements and modifications without departing from the principles of this application, and these improvements and modifications are also considered to be within the scope of protection of this application.

Claims

1. A battery casing, characterized in that, The battery housing includes a cover plate and a housing body. Along a first direction, at least one end of the housing body has an opening. The cover plate is adapted to cover the opening of the housing body by a welded portion and form a receiving space. The cover plate has a first surface and a second surface disposed opposite to each other, wherein the first surface is the side of the cover plate facing away from the receiving space; The sidewall of the shell body has a third surface and a fourth surface arranged opposite to each other, wherein the third surface is the side surface of the shell body that is away from the receiving space; The welding portion includes a first welding portion; On a cross-section of the battery casing perpendicular to a third direction, the intersection point of the first welded part and the first surface is A, and the intersection point of the first welded part and the third surface is B. The third direction is perpendicular to the first direction. The angle between the extension line of the outline of the third surface on the cross-section and the line connecting points A and B is α, where 0 < α < 90°. The extension line extends from point B toward the plane containing the second surface and along the first direction. Wherein, the distance from point B to the plane containing the first surface of the cover plate is W1, the distance from point A to the second surface is W2, and the distance from point B to the fourth surface is W3, and W1, W2, and W3 are in the same unit; the first welded part satisfies: 0.2W3≤(W1-W2)×tanα≤W3.

2. The battery casing according to claim 1, characterized in that, 30°≤α≤60°。 3. The battery casing according to claim 1, characterized in that, In the direction toward the receiving space, the outer edge of the first welded portion does not exceed the second surface and the fourth surface.

4. The battery casing according to claim 1, characterized in that, The orthographic projection of point A onto the second surface is point A', and point A' is located within the orthographic projection of the shell body onto the cover plate or on its boundary.

5. The battery casing according to any one of claims 1-4, characterized in that, Along the second direction and the third direction, the orthographic projection of the cover plate and the orthographic projection of the shell body do not overlap, and the first direction, the second direction and the third direction are perpendicular to each other.

6. The battery casing according to any one of claims 1-5, characterized in that, In the first direction, there is a gap between the shell body and the cover plate; the width of the gap is L1, 0. <L1≤0.05mm。 7. The battery casing according to any one of claims 1-4, characterized in that, The first weld portion protrudes relative to the first surface and / or the third surface, and the maximum protrusion of the first weld portion relative to the first surface is L2; ​​the maximum protrusion of the first weld portion relative to the third surface is L3; 0 <L2≤0.05 mm;0<L3≤0.05 mm。 8. The battery casing according to any one of claims 1-4, characterized in that, The distance from point A to the second surface is W2, and the distance from point B to the fourth surface is W3, where 0.05mm ≤ W2 ≤ W3.

9. The battery casing according to claim 8, characterized in that, When W2 < W3, 30° ≤ α ≤ 45°.

10. The battery casing according to any one of claims 1-9, characterized in that, Along the first direction, the two ends of the shell body have openings, and the battery shell includes two of the cover plates; The second surface is the surface with the largest surface area of ​​the battery casing.

11. A battery, characterized in that, The battery includes a battery housing as described in any one of claims 1-10, and an electrode core; wherein the electrode core is housed in the receiving space of the battery housing.

12. An electrical appliance, characterized in that, The electrical device includes the battery as described in claim 11.

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