A battery case and a battery

Abstract

The utility model provides a kind of battery shell and battery, wherein, battery shell includes shell body, the explosion vent hole being opened in shell body, and the explosion vent hole is sealed with the explosion vent hole cooperation and explosion vent piece, explosion vent piece is fixed in shell body by the welding layer formed by welding track, welding layer includes first track and second track, wherein first track is long side section, starting weld point is set on first track, can provide linear heat transfer path to avoid heat accumulation, heat two-way symmetrical diffusion can also significantly reduce thermal stress gradient, and provide enough power buffer space, starting weld point is also away from geometric mutation area to reduce stress concentration coefficient, by reconstructing starting weld point position, avoid the risk that explosion vent piece welding appears warping, welds and leaks, solve the structural failure problem of thin-walled shell explosion valve, synergistically realize power battery energy density promotion and safety performance promotion.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a battery casing and a battery. Background Technology

[0002] In power battery design, the structural reliability and process adaptability of the battery casing are fundamental to ensuring battery safety and production efficiency. Insufficient matching between the battery casing's structural design and manufacturing process can lead to problems such as limited battery energy density, reduced thermal runaway protection, and lower mass production yield. Therefore, achieving both structural reliability and process adaptability in the casing design, while simultaneously improving battery safety and energy density, has become a critical issue that urgently needs to be addressed in battery structure technology. Utility Model Content

[0003] This utility model provides a battery casing and a battery to solve the technical problem that welding explosion-proof valves can easily cause warping, burn-through, and leakage risks.

[0004] This utility model provides a battery casing, including a casing body, an explosion-proof hole formed in the casing body, and an explosion-proof sheet that cooperates with and seals the explosion-proof hole.

[0005] The explosion-proof sheet is fixed to the housing body by a welding layer formed by welding tracks. The welding layer includes two first tracks that are arranged opposite to each other and extend along a first direction, and two second tracks located at both ends of the first tracks and connecting the ends of the two first tracks. The maximum distance between the two second tracks in the first direction is greater than the maximum distance between the two first tracks perpendicular to the first direction.

[0006] The maximum dimension of the explosion-proof sheet in the first direction is the length L of the explosion-proof sheet, and the maximum dimension perpendicular to the first direction is the width W of the explosion-proof sheet, which satisfies: 3≤L / W≤8;

[0007] The starting weld point of the welding trajectory is located on the first trajectory.

[0008] In one embodiment of the present invention, the outer contour of the explosion-proof sheet includes two straight segments arranged opposite to each other and extending along the first direction, and an arc segment located at both ends of the straight segments and connecting the ends of the two straight segments.

[0009] The length L of the explosion-proof sheet is the maximum distance between the vertices of the two arc segments in the first direction, and the width W of the explosion-proof sheet is the maximum distance between the two straight segments perpendicular to the first direction, satisfying: 3≤L / W≤5.

[0010] In one embodiment of this utility model, the straight-line distance from the starting solder point to the connection point of the first trajectory and the second trajectory is D, which satisfies: D≥2mm.

[0011] In one embodiment of the present invention, the starting solder point is located at the middle position of the first trajectory.

[0012] In one embodiment of the present invention, the termination weld point of the welding trajectory and the starting weld point form a weld overlap area on the first trajectory.

[0013] In one embodiment of this utility model, the length of the weld overlap area along the extension direction of the welding trajectory is 0.1mm to 0.5mm.

[0014] In one embodiment of the present invention, the welding layer includes an annular connecting area formed by a fusion line, the fusion line extending along the outer contour of the explosion-proof sheet;

[0015] The annular connection area is located at the connection between the explosion-proof plate and the housing body, and is integrally connected with the two to seal the explosion-proof hole. The orthographic projection area of ​​the annular connection area on the surface of the housing body is S1, which satisfies: 10mm². 2 ≤S1≤30mm 2 .

[0016] In one embodiment of this utility model, the outer periphery of the explosion-proof sheet partially overlaps and fits with the shell body. The orthographic projection area of ​​the overlapping part on the surface of the shell body is the overlapping area, and the effective overlapping area per unit length is S2. The wall thickness of the shell body is t, which satisfies the relationship: S2 = 1.5t.

[0017] In one embodiment of this utility model, the outer periphery of the explosion-proof sheet partially overlaps and adheres to the shell body. The projected area of ​​the overlapping portion on the surface of the shell body is the overlapping area, and the effective overlapping area per unit length is S2, which satisfies: 0.2mm. 2 ≤S2≤0.75mm 2 .

[0018] This utility model also provides a battery, comprising:

[0019] As described in any of the above embodiments, the battery housing is a housing body formed by bending a sheet metal and connecting it with a weld, an explosion-proof hole opened in the housing body, and an explosion-proof sheet that cooperates with and seals the explosion-proof hole, wherein at least one end of the housing body is provided with an opening;

[0020] The electrode assembly is disposed within the housing body;

[0021] A cover plate, which is sealed and welded to the opening of the housing body.

[0022] The beneficial effects of this utility model are as follows: The battery casing and battery proposed in this utility model form a long-side welding path foundation in the defined welding layer, and set the starting welding point on the first trajectory, i.e. the long side segment, on this structure. By utilizing the linear heat transfer characteristics of the long-side straight structure, heat accumulation at the corner is avoided. Heat diffuses bidirectionally along the long side, thereby significantly reducing the thermal stress gradient and optimizing the heat distribution. At the same time, the large contact area of ​​the long side segment enhances the rigid constraint during welding, suppresses free deformation at the end, and effectively avoids the risk of warping, burn-through and leakage during the welding of the explosion-proof sheet.

[0023] The starting weld point is far from the geometric change zone from the corner, thereby reducing the stress concentration factor and improving structural safety. The long side section can provide power buffer space to avoid insufficient strength or weld penetration caused by power fluctuations in the initial stage of welding. At the same time, it is convenient to implement processes such as segmented skip welding or progressive spiral welding, actively disperse heat accumulation, and improve process controllability.

[0024] By limiting the aspect ratio of the explosion-proof disc, the rigidity requirement and deformation control are balanced, the fluctuation of burst pressure is reduced, and the abnormal rise in burst pressure caused by excessive rigidity due to an excessively small aspect ratio or the risk of end warping caused by an excessively large aspect ratio is avoided.

[0025] By combining the design of the shell body and the explosion-proof sheet, and reconstructing the starting weld point, the explosion-proof sheet welding is adapted to the thin-walled shell, eliminating the risk of end warping and weld burn-through, achieving a balance between thermal stress control and structural stability, ensuring the welding reliability of the explosion-proof valve, avoiding sealing failure, and achieving a fundamental improvement in battery energy density and safety reliability. Attached Figure Description

[0026] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0027] In the attached diagram:

[0028] Figure 1 A schematic diagram of a structure where welding begins at the corner of an explosion-proof valve on a battery casing;

[0029] Figure 2 This is a schematic diagram of the structure of a battery casing provided in one embodiment of the present invention.

[0030] The attached figures are labeled as follows:

[0031] 100. Shell body; 200. Explosion-proof sheet; 210. Straight section; 220. Curved section. Detailed Implementation

[0032] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0033] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0034] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the present invention. However, it will be apparent to those skilled in the art that embodiments of the present invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the present invention.

[0035] Most power battery casings are made of aluminum alloy, which, while easy to process, is limited by material properties, resulting in a relatively large thickness, low strength, and poor high-temperature resistance. This makes them prone to burn-through and thermal runaway risks during thermal runaway. Furthermore, the excessively thick casing reduces the utilization of internal battery space, impacting battery safety and energy density. To improve energy density and safety, there is a growing trend towards thin-walled stainless steel casings. These casings utilize the high strength and high temperature resistance of stainless steel to enhance battery energy density and safety. Explosion-proof valves, acting as pressure relief safety devices during battery thermal runaway, typically employ a long, narrow, racetrack-shaped structure welded to the casing. In the welding process, the starting weld point is generally placed at the corner, such as... Figure 1As shown. However, the corner area suffers from problems such as a sharp increase in local temperature at the moment of arc initiation, triaxial stress imbalance during cooling and contraction, and impeded heat conduction, which can easily lead to warping, weld penetration, and leakage. Especially during the arc initiation and termination stages, local molten pools are prone to forming arc craters, which can induce cracks, reduce welding strength, and lead to weld penetration and sealing failure. This seriously affects the sealing reliability and explosion consistency of the explosion-proof valve, thereby reducing the safety and reliability of battery use. To address this, this utility model proposes a battery casing and battery. By reconstructing the initial weld point and synergistically optimizing the structural design and process of the explosion-proof sheet, the risks of warping, weld penetration, and leakage caused by explosion-proof valve welding are effectively solved, improving the reliability of the structure. The structural design of the battery casing effectively improves the battery's energy density and safety.

[0036] Please see Figure 2 A battery casing provided in one embodiment of the present invention includes a casing body 100, an explosion-proof hole formed in the casing body 100, and an explosion-proof plate 200 that cooperates with and seals the explosion-proof hole. The explosion-proof plate 200 is fixed to the casing body 100 by a weld layer formed by welded tracks. The weld layer includes two first tracks arranged opposite each other and extending along a first direction, and two second tracks located at both ends of the first tracks and connecting the ends of the two first tracks. The maximum distance between the two second tracks in the first direction is greater than the distance between the two first tracks perpendicular to the first direction. The maximum distance, the starting weld point of the welding trajectory is located on the first trajectory; the maximum dimension of the explosion-proof plate 200 in the first direction is the length L of the explosion-proof plate 200, and the maximum dimension perpendicular to the first direction is the width W of the explosion-proof plate 200, which satisfies: 3≤L / W≤8. The length-to-width ratio (i.e., L / W) range is determined by optimizing the explosion-proof valve structure through the balance of mechanical properties and deformation control. When the length-to-width ratio is less than 3, it is easy to cause excessive rigidity and abnormal rise in burst pressure. When the length-to-width ratio is greater than 8, structural instability will aggravate the tendency of end warping, and it is necessary to add reinforcing ribs to increase the process complexity.

[0037] The battery casing of this invention sets the starting weld point on the first trajectory, i.e., the long side segment. The first trajectory provides a linear heat transfer path, thereby avoiding heat accumulation at corners, achieving uniform heat input, and allowing heat to diffuse symmetrically in both directions along the long side, which can significantly reduce lateral temperature difference and thermal stress gradient. The long side segment has a large contact area with the casing body 100, which enhances rigidity and suppresses free deformation at the ends. The starting weld point is far from the geometric change zone, reducing the stress concentration factor. The length of the first trajectory also provides sufficient power buffer space, avoiding the risk of insufficient penetration or burn-through caused by initial power fluctuations in welding, supporting heat accumulation dispersion processes such as segmented skip welding or progressive spiral welding, and improving process controllability. By reconstructing the position of the starting weld point, in conjunction with the aspect ratio design of the explosion-proof sheet 200, the risk of warping, burn-through, and leakage during the welding of the explosion-proof sheet 200 is avoided, improving battery safety.

[0038] Please see Figure 2 In an optional embodiment of this utility model, the shell body 100 can be made of stainless steel, such as SUS304, with a wall thickness of 0.2mm to 0.5mm. The thin-walled structure, combined with the high melting point of stainless steel, synergistically achieves a significant increase in battery energy density and an effective extension of thermal runaway response time. It should be noted that the material of the shell body 100 is not limited. When other materials are selected, welding process parameters, such as heat input power, can be dynamically optimized based on the material's thermophysical properties to match its key characteristics such as thermal conductivity and coefficient of thermal expansion, ensuring the reliability and sealing integrity of the explosion-proof sheet 200 welding.

[0039] Please see Figure 2 In an optional embodiment of this utility model, the outer contour of the explosion-proof plate 200 includes two opposing straight segments 210 extending along a first direction and an arc-shaped segment 220 located at both ends of the straight segments 210 and connecting the ends of the two straight segments 210. It is understood that the shape of the weld layer matches the outer contour of the explosion-proof plate 200 to ensure welding sealing quality and process stability; that is, the first trajectory is a straight trajectory, and the second trajectory is an arc-shaped trajectory. The length L of the explosion-proof plate 200 is the maximum distance between the vertices of the two arc-shaped segments 220 in the first direction, and the width W of the explosion-proof plate 200 is the maximum distance between the two straight segments 210 perpendicular to the first direction. The length L and width W of the explosion-proof plate 200 satisfy: 3 ≤ L / W ≤ 5. By synergistically optimizing the aspect ratio of the explosion-proof plate 200 through structural stiffness and deformation characteristics, abnormal increases in burst pressure caused by excessive rigidity are effectively avoided, and the tendency for end warping caused by long dimensions is suppressed, thereby avoiding process redundancy caused by adding reinforcing ribs. This size ratio design effectively improves the structural stability of the explosion-proof valve.

[0040] Please see Figure 2 In an optional embodiment of this utility model, the starting weld point of the welding path of the explosion-proof sheet 200 is set on the first trajectory, and the straight-line distance from the starting weld point to the connection point of the first trajectory and the second trajectory is D, which satisfies: D≥2mm. By quantitatively controlling the position of the starting weld point through D≥2mm, it is ensured that the starting weld point is far away from the geometric change zone, the stress concentration coefficient is reduced, and thermal management optimization, mechanical constraint strengthening, and process controllability improvement can be achieved, avoiding warping, weld burn-through, and leakage during welding, and eliminating the risk of failure. The aspect ratio design of the explosion-proof sheet 200 and the positioning of the starting weld point work together to effectively suppress warping and eliminate risks such as weld burn-through, solving the risk of failure from both structural stability and thermal control paths, and improving the safety and reliability of the explosion-proof valve.

[0041] Please see Figure 2In an optional embodiment of this invention, the starting weld point is located at the middle position of the first trajectory. The heat conduction symmetry at the middle position is optimal, which can maximize the reduction of the lateral temperature gradient during the welding process; at the same time, the sufficient length provided by the middle region forms an effective power buffer space, which can effectively absorb the power fluctuations in the initial stage of welding, prevent insufficient penetration or burn-through from causing a decrease in connection strength, and improve the welding strength of the explosion-proof sheet 200. It should be noted that the middle position is the allowable tolerance area including the geometric center of the straight trajectory. Setting the starting weld point within this area can meet the requirements of heat distribution optimization and process stability, and avoid strength defects caused by unstable arc power during welding.

[0042] Please see Figure 2 In an optional embodiment of this utility model, the termination weld point and the starting weld point of the welding path form a weld overlap area on the first trajectory, ensuring the closure integrity of the welding trajectory and eliminating weak points in the seal caused by path interruption. When the starting weld point is positioned in the middle area of ​​the first trajectory, the arc termination position is simultaneously set in the middle of the first trajectory, effectively avoiding the arc crater sensitive area at the connection between the straight trajectory and the arc trajectory, thereby avoiding the risk of end cracking. It should be noted that the welding path of the first trajectory supports segmented skip welding or progressive spiral welding processes, which can improve process controllability by actively dispersing heat accumulation.

[0043] Please see Figure 2 In an optional embodiment of this utility model, the length of the weld overlap area along the extension direction of the welding trajectory is set to 0.1mm to 0.5mm. When the length is less than 0.1mm, it is easy to cause insufficient weld continuity, which may lead to sealing failure; when it is greater than 0.5mm, it will expand the heat-affected zone and cause structural deformation. By reasonably setting the length of the weld overlap area, the integrity of the welding interface and the reliability of the seal are ensured.

[0044] Please see Figure 2 In an optional embodiment of this invention, the length of the weld overlap zone along the extension direction of the welding trajectory is further preferably 0.18 mm to 0.22 mm. This critical range simultaneously optimizes weld continuity and heat-affected zone control, minimizing the risk of thermal damage while meeting welding strength requirements, thus achieving a highly reliable seal for the explosion-proof valve.

[0045] Please see Figure 2In an optional embodiment of this utility model, the welded layer includes an annular connection area formed by a fusion line. The fusion line extends along the outer contour of the explosion-proof sheet 200. The annular connection area is located at the connection between the explosion-proof sheet 200 and the housing body 100 and is integrally connected to seal the explosion-proof hole. It should be noted that during the welding process, a molten pool is generated at the contact interface between the explosion-proof sheet 200 and the housing body 100. The interface trace formed after the liquid metal of the molten pool solidifies is the fusion line, and the annular connection area formed by it is the solidified area of ​​the molten pool after solidification. The orthogonal projection area of ​​the annular connection area on the surface of the housing body 100 is S1, which is the connection area of ​​the molten pool, and it satisfies: 10mm. 2 ≤S1≤30mm 2 .

[0046] It is understandable that during the welding process, the molten metal in the weld pool undergoes metallurgical bonding with the base material. After solidification, an annular connection area is formed at the interface between the explosion-proof plate 200 and the shell body 100. The outline of the weld pool forms a boundary fusion line. The coverage area S1 of the annular connection area affects the welding strength and sealing performance. When the area is less than 10mm... 2 Insufficient penetration depth can lead to substandard tensile strength, easily causing seal failure. Penetration depth greater than 30mm is also problematic. 2 Excessive heat accumulation can lead to grain coarsening, posing a risk of thermal damage and material performance degradation. By designing and controlling the welding heat input within this range, an optimal balance can be established between interfacial bonding strength and heat-affected zone control, ensuring the integrity of the weld quality. It is understandable that controlling the joint area during welding requires coordinated adjustment of process parameters such as welding power and welding speed.

[0047] Please see Figure 2 In an optional embodiment of this utility model, the coverage area S1 of the annular connecting region is further preferably 15mm. 2 ~25mm 2 As the core area where the explosion-proof disc 200 and the shell body 100 are metallurgically fused, its coverage area is designed based on the structural characteristics and thermophysical properties of the explosion-proof disc 200. By controlling the area of ​​the fusion zone, heat damage is minimized while meeting welding strength requirements, achieving stable and reliable welding quality and improving the sealing reliability of the explosion-proof valve; lower limit 15mm. 2 Ensure sufficient penetration and avoid insufficient interfacial bonding; maximum 25mm. 2 Inhibits microscopic tissue damage caused by overheating.

[0048] Please see Figure 2In an optional embodiment of this utility model, the outer periphery of the explosion-proof sheet 200 partially overlaps and adheres to the shell body 100. The orthographic projection area of ​​the overlapping portion on the surface of the shell body 100 is the overlapping area, and the effective overlapping area per unit length is S2. The wall thickness of the shell body 100 is t, which satisfies the relationship: S2 = 1.5t. Because the thin-walled shell diffuses heat quickly, thermal stress concentration can easily lead to edge warping or yielding deformation. To adapt to the thin-walled characteristics of the shell body 100, the effective overlapping area S2 per unit length can be dynamically calculated based on the thickness of the shell body 100. For example, when the wall thickness t = 0.3 mm, S2 = 0.45 mm. 2 This ensures effective heat transfer during welding while mitigating the risk of thermal stress concentration, guaranteeing reliable sealing and structural stability, and achieving a balance between mechanical strength, burst sensitivity, and weld controllability. It is understood that in other embodiments, when using shell bodies 100 made of different materials, the area can be determined by appropriately adjusting the scaling factor based on the material's thermal conductivity and other factors.

[0049] Please see Figure 2 In an optional embodiment of this utility model, for the overlapping portion of the outer periphery of the explosion-proof sheet 200 and the shell body 100, if the area is too large, the welding heat input is large, which can easily cause deformation of the explosion-proof sheet 200 or thermal stress concentration. If the overlapping area is too small, the assembly requirements are high, and the risk of incomplete welding and misalignment will increase. Insufficient welding strength will also lead to air leakage during use. By designing the structure of the overlapping portion through the thin-wall welding failure mechanism, the effective overlapping area S2 per unit length of the overlapping portion of the outer periphery of the explosion-proof sheet 200 and the shell body 100 is set to 0.2 mm. 2 ~0.75mm 2 This ensures welding strength and prevents excessive heat input from degrading material properties, thus fundamentally improving the safety and reliability of explosion-proof valves. When the area S2 is less than 0.2mm²... 2 At this time, insufficient effective sealing interface can easily lead to leakage; area S2 is greater than 0.75mm. 2 At this time, excessive thermal stress may occur, causing shell deformation or affecting the blasting performance.

[0050] Please see Figure 2This utility model also proposes a battery, including a battery casing, an electrode assembly, and a cover plate as described in any of the above embodiments. The battery casing includes a casing body 100 and an explosion-proof sheet 200, wherein the casing body 100 is formed by bending a sheet metal and connecting it with a weld, and has an explosion-proof hole. The explosion-proof sheet 200 cooperates with the explosion-proof hole and seals the explosion-proof hole. At least one end of the casing body 100 is provided with an opening. The electrode assembly is disposed inside the casing body 100, and the cover plate is sealed and welded to the opening of the casing body 100. The thin-walled shell design significantly improves energy density. During the welding of the explosion-proof valve, the starting weld point is positioned in the center of the long side trajectory. Combined with the optimized aspect ratio design of the explosion-proof plate 200, the risks of warping, weld penetration, and leakage are avoided, while ensuring the stability of the burst pressure. Through weld overlap control, annular connection area constraint, and dynamic matching of the effective overlap area per unit length between the shell body 100 and the explosion-proof plate 200 with the thickness of the shell body 100, the welding quality is ensured to be stable and reliable. This synergistically guarantees the structural sealing and thermal stability of the thin-walled shell, significantly improving the explosion-proof safety and energy density of the battery. This enables the battery to achieve a synergistic breakthrough in safety reliability, energy storage efficiency, and process consistency.

[0051] In summary, the battery casing and battery of this utility model eliminate warping, burn-through, and end cracks caused by heat accumulation by positioning the starting weld point on the long side trajectory of the weld layer and controlling the starting and ending weld points to be in the middle area of ​​the long side trajectory. The optimized aspect ratio design of the explosion-proof plate 200 balances the stability of burst pressure and the anti-warping capability. The design of the weld overlap area effectively ensures the welding continuity and suppresses thermal damage. The control of the area of ​​the annular connection area takes into account both tensile strength and thermal stability. The effective overlapping area per unit length of the casing body 100 and the explosion-proof plate 200 is dynamically matched with the wall thickness of the casing body 100 to adapt to the thin-wall deformation characteristics. The synergistic effect of each structure solves the leakage risk of the explosion-proof valve of the thin-wall casing, and while maintaining the structural functional balance, it achieves a substantial improvement in battery energy density and safety reliability.

[0052] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

[0053] Throughout this description, numerous specific details, such as examples of components and / or methods, are provided to provide a complete understanding of embodiments of the present invention. However, those skilled in the art will recognize that embodiments of the present invention may be practiced without one or more of these specific details or by other devices, systems, components, methods, parts, materials, components, etc. In other instances, well-known structures, materials, or operations have not been specifically shown or described in detail to avoid obscuring aspects of embodiments of the present invention.

[0054] Throughout this specification, references to "an embodiment," "an embodiment," or "a specific embodiment" mean that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention, but not necessarily in all embodiments. Therefore, the various representations of the phrases "in one embodiment," "in an embodiment," or "in a specific embodiment" in different places throughout the specification do not necessarily refer to the same embodiment. Furthermore, a particular feature, structure, or characteristic of any specific embodiment of the present invention can be combined with one or more other embodiments in any suitable manner. It should be understood that other variations and modifications of the embodiments of the present invention described and illustrated herein may be based on the teachings herein and will be considered part of the spirit and scope of the present invention.

[0055] It should also be understood that one or more of the elements shown in the figures may be implemented in a more separate or more integrated manner, or may even be removed because they are inoperable in certain circumstances or provided because they may be useful for a particular application.

[0056] Furthermore, unless otherwise expressly stated, any arrows in the accompanying drawings should be considered illustrative only and not limiting. Additionally, unless otherwise stated, the term "or" as used herein is generally intended to mean "and / or". Where a term is anticipated to provide a separation or combination capability that is unclear, a combination of components or steps will also be considered as indicated.

[0057] As used herein and throughout the claims below, unless otherwise specified, “a” and “the” include the plural references. Similarly, as used herein and throughout the claims below, unless otherwise specified, “in” means “in” and “on”.

[0058] The above description of the embodiments shown in this utility model (including the content set forth in the abstract of the specification) is not intended to be an exhaustive enumeration or to limit the utility model to the precise forms disclosed herein. Although specific embodiments and examples of the utility model have been described herein for illustrative purposes only, various equivalent modifications are possible within the spirit and scope of the utility model, as will be recognized and understood by those skilled in the art. As indicated, these modifications can be made to the utility model in accordance with the above description of the embodiments described herein, and such modifications will be within the spirit and scope of the utility model.

[0059] This document has generally described the systems and methods in detail to aid in understanding the present invention. Furthermore, various specific details have been set forth to provide a general understanding of embodiments of the present invention. However, those skilled in the art will recognize that embodiments of the present invention can be practiced without one or more specific details, or using other devices, systems, accessories, methods, components, materials, parts, etc. In other instances, well-known structures, materials, and / or operations have not been specifically shown or described in detail to avoid obscuring aspects of embodiments of the present invention.

[0060] Therefore, although the present invention has been described herein with reference to specific embodiments thereof, freedom of modification, various changes and substitutions are also within the scope of the above disclosure, and it should be understood that in some cases, certain features of the present invention may be adopted without departing from the scope and spirit of the invention and without corresponding use of other features. Thus, many modifications can be made to adapt a particular environment or material to the essential scope and spirit of the present invention. The present invention is not intended to be limited to the specific terms used in the following claims and / or the specific embodiments disclosed as the best mode of carrying out the present invention, but the present invention will include any and all embodiments and equivalents falling within the scope of the appended claims. Therefore, the scope of the present invention will be determined only by the appended claims.

Claims

1. A battery casing, characterized in that, It includes a housing body, an explosion-proof hole formed in the housing body, and an explosion-proof plate that cooperates with and seals the explosion-proof hole, wherein, The explosion-proof sheet is fixed to the housing body by a welding layer formed by welding tracks. The welding layer includes two first tracks that are arranged opposite to each other and extend along a first direction, and two second tracks located at both ends of the first tracks and connecting the ends of the two first tracks. The maximum distance between the two second tracks in the first direction is greater than the maximum distance between the two first tracks perpendicular to the first direction. The maximum dimension of the explosion-proof sheet in the first direction is the length L of the explosion-proof sheet, and the maximum dimension perpendicular to the first direction is the width W of the explosion-proof sheet, which satisfies: 3≤L / W≤8; The starting weld point of the welding trajectory is located on the first trajectory.

2. The battery casing according to claim 1, characterized in that, The outer contour of the explosion-proof sheet includes two straight segments arranged opposite each other and extending along the first direction, and an arc segment located at both ends of the straight segments and connecting the ends of the two straight segments. The length L of the explosion-proof sheet is the maximum distance between the vertices of the two arc segments in the first direction, and the width W of the explosion-proof sheet is the maximum distance between the two straight segments perpendicular to the first direction, satisfying: 3≤L / W≤5.

3. The battery casing according to claim 1, characterized in that, The straight-line distance from the starting solder point to the connection point of the first trajectory and the second trajectory is D, which satisfies: D≥2mm.

4. The battery casing according to claim 1, characterized in that, The starting solder joint is located in the middle of the first trajectory.

5. The battery casing according to claim 1, characterized in that, The termination point of the welding trajectory and the starting point form a weld overlap area on the first trajectory.

6. The battery casing according to claim 5, characterized in that, The length of the weld overlap zone along the extension direction of the welding trajectory is 0.1 mm to 0.5 mm.

7. The battery casing according to claim 1, characterized in that, The weld layer includes an annular connection area enclosed by a fusion line, which extends along the outer contour of the explosion-proof sheet; The annular connection area is located at the connection between the explosion-proof plate and the housing body, and is integrally connected with the two to seal the explosion-proof hole. The orthographic projection area of ​​the annular connection area on the surface of the housing body is S1, which satisfies: 10mm². 2 ≤S1≤30mm 2 .

8. The battery casing according to claim 1, characterized in that, The outer periphery of the explosion-proof sheet overlaps and fits with the shell body. The projected area of ​​the overlapping part on the surface of the shell body is the overlapping area. The effective overlapping area per unit length is S2. The wall thickness of the shell body is t, which satisfies the relationship: S2 = 1.5t.

9. The battery casing according to claim 1, characterized in that, The outer periphery of the explosion-proof sheet partially overlaps and adheres to the housing body. The projected area of ​​the overlapping portion on the surface of the housing body is the overlapping area, and the effective overlapping area per unit length is S2, which satisfies: 0 .2mm 2 ≤S2≤0.75mm 2 。 10. A battery, characterized in that, include: The battery casing as described in any one of claims 1 to 9, the battery casing comprising a casing body formed by bending a sheet metal and connecting it with a weld, an explosion-proof hole provided in the casing body, and an explosion-proof sheet that cooperates with and seals the explosion-proof hole, wherein at least one end of the casing body is provided with an opening; The electrode assembly is disposed within the housing body; A cover plate, which is sealed and welded to the opening of the housing body.

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