A battery case and a battery

Abstract

The utility model provides a kind of battery shell and battery, battery shell includes first surface and with the second surface and third surface of first surface adjacent and located in the opposite sides of first surface, wherein first surface is connected with second surface, third surface by bending surface, it is provided with explosion-proof piece on first surface, the connecting position of bending surface and first surface forms bending edge line, its minimum distance from the edge of explosion-proof piece is D, by minimum distance D dynamic correlation shell wall thickness, and fusion explosion-proof piece length-width ratio and process coefficient construct distance model, eliminate the welding cracking of first welding after bending and the rebound deformation risk of first bending after welding, inhibit the fluctuation of burst pressure;Through the system integration of thin-walled steel shell and accurate explosion-proof distance, realize the essential promotion of space utilization and thermal safety performance, synchronous optimization battery energy density and anti-thermal diffusion capacity.

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 battery structural design, the rationality of the battery cell casing's structural design directly affects the battery's energy density and safety performance. An unreasonable casing design and a lack of scientific models to guide key structural parameters can lead to decreased casing reliability, hindering battery performance improvement and causing significant fluctuations in product yield. Therefore, how to collaboratively optimize the casing's structural design has become a core challenge for improving overall battery performance. Utility Model Content

[0003] This invention provides a battery casing and a battery to solve the technical problems of structural failure risk and burst pressure fluctuation caused by process conflicts during casing manufacturing.

[0004] This utility model provides a battery casing, including a first surface and a second and a third surface adjacent to the first surface and located on opposite sides of the first surface;

[0005] The first surface is connected to the second surface and the third surface through a bent surface. The bent surface is a transition surface between the first surface and the second surface and between the first surface and the third surface. A bent edge line is formed at the connection position between the bent surface and the first surface. An explosion-proof sheet is provided on the first surface.

[0006] In the plane of the first surface, the bending edge extends along the first direction, and the second direction is perpendicular to the first direction. In the second direction, the minimum distance between the bending edge and the edge of the explosion-proof sheet is D. The minimum distance D and the wall thickness t of the shell satisfy the following relationship: D≥1.5t.

[0007] In one embodiment of this utility model, the minimum distance D and the wall thickness t of the shell satisfy the following relationship: D≥3t.

[0008] In one embodiment of this utility model, the maximum length of the explosion-proof sheet in the first direction is L, and the maximum width in the second direction is W. When L / W>4, the minimum distance D and the wall thickness t of the shell satisfy the relationship: D≥4t.

[0009] In one embodiment of this utility model, the maximum length of the explosion-proof sheet in the first direction is L, and the maximum width in the second direction is W. When L / W < 3, the minimum distance D and the wall thickness t of the shell satisfy the relationship: D ≥ 2t.

[0010] In one embodiment of the present invention, the maximum length of the explosion-proof sheet in the first direction is L, and the maximum width in the second direction is W;

[0011] The minimum distance D, the wall thickness t of the shell, and the maximum length L and maximum width W of the explosion-proof sheet satisfy the following relationship: D min =K*t*(1+L / W), where K takes values ​​from 1 to 2.

[0012] In one embodiment of this utility model, the maximum length L and the maximum width W of the explosion-proof sheet satisfy the relationship: 3≤L / W≤8.

[0013] In one embodiment of this utility model, the maximum length L and the maximum width W of the explosion-proof sheet satisfy the relationship: 3≤L / W≤5.

[0014] In one embodiment of the present invention, the explosion-proof sheet is fixed to the first surface by a first weld, the first weld extending continuously along the outer periphery of the explosion-proof sheet, and a cryogenic strengthening zone is also formed on the surface of the shell, the cryogenic strengthening zone being a strip-shaped area surrounding the first weld that extends outward from the boundary of the first weld and continuously along the trajectory of the first weld.

[0015] In one embodiment of the present invention, a stress relief area is further provided between the bending edge and the explosion-proof sheet on the first surface. The stress relief area is a strip-shaped area extending along the first direction, and the minimum distance between the stress relief area and the bending edge in the second direction is 1 mm.

[0016] This utility model also proposes a battery, comprising:

[0017] The battery housing as described in any of the above embodiments is a structure with an internal cavity formed by bending a sheet metal and connecting it with a second weld, and at least one end of the battery housing is provided with an opening;

[0018] Electrode assembly, disposed within the battery casing;

[0019] A cover plate, which is sealed and welded to the opening of the battery casing.

[0020] The beneficial effects of this utility model are as follows: The battery casing and battery proposed in this utility model adopt a structural design that dynamically correlates the minimum distance between the edge of the explosion-proof sheet and the bending edge with the casing wall thickness. Through distance design, a stress gradient attenuation zone is formed, realizing physical isolation between the bending deformation zone and the welding heat-affected zone, thereby eliminating the risk of deformation failure caused by process conflicts and stabilizing the explosion-proof pressure; the distance is dynamically adjusted based on the wall thickness, avoiding redundant space occupation caused by fixed values; a multi-parameter coupling model is established by combining wall thickness and aspect ratio, which can achieve multi-condition adaptation; through the integrated design of a quantifiable and accurate distance model and a thin-walled casing, the casing strength, process compatibility and explosion-proof performance are unified, space utilization and thermal safety performance are improved, and the synergistic optimization of battery safety and energy density is achieved. Attached Figure Description

[0021] 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.

[0022] In the attached diagram:

[0023] Figure 1 This is a schematic diagram of the structure of a battery casing provided in one embodiment of the present invention.

[0024] The attached figures are labeled as follows:

[0025] 100, First side; 200, Second side; 300, Third side; 400, Bending side; 500, Explosion-proof sheet; 410, Bending edge. Detailed Implementation

[0026] 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.

[0027] 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.

[0028] 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.

[0029] Aluminum alloys, commonly used in the manufacture of power battery casings, have good machinability but low strength and poor high-temperature resistance. This necessitates increasing the casing thickness to meet structural strength requirements, leading to reduced internal space utilization, limited energy density, and increased risk of thermal runaway. Furthermore, aluminum alloy casings are prone to burn-through during thermal runaway, posing a thermal diffusion risk. To improve energy density, thin-walled casings can be made from steel with relatively higher strength and better high-temperature resistance. Double-walled steel casings are typically formed using bending and seam welding, with explosion-proof tabs generally welded to the smaller surfaces of the casing. In manufacturing, there is a conflict between bending and welding processes: if the explosion-proof sheet is welded first and the shell is bent, the bending stress may cause cracking in the heat-affected zone; if the shell is bent first and the explosion-proof sheet is welded, the welding heat input may cause springback deformation in the bending area. To eliminate the deformation risk caused by the process sequence, it is necessary to reasonably control the welding position of the explosion-proof sheet and the edge distance of the bending area. The design of this edge distance usually relies on the engineer's experience and is often used in the range of 2mm-6mm. Since the experience-based value does not establish a mathematical correlation model with the shell wall thickness and the aspect ratio of the explosion-proof sheet, it will lead to large fluctuations in burst pressure. To address this, this utility model proposes a battery shell and battery that establishes a distance design model to accurately control the welding position of the explosion-proof sheet, thus solving the problems of deformation risk and burst pressure fluctuation caused by process conflict.

[0030] Please see Figure 1This invention provides a battery casing according to an embodiment of the present invention, comprising a first surface 100 and a second surface 200 and a third surface 300 adjacent to the first surface 100 and located on opposite sides of the first surface 100. The battery casing is formed by bending and then welded together to form an integral structure. The first surface 100 is connected to the second surface 200 and the third surface 300 through a bending surface 400. An explosion-proof sheet 500 is provided on the first surface 100. The bending surface 400 is a transition surface between the first surface 100 and the second surface 200 and between the first surface 100 and the third surface 300. A bending edge line 410 is formed at the connection position between the bending surface 400 and the first surface 100. In the plane of the first surface 100, the bending edge line 410 extends along a first direction, and a second direction is perpendicular to the first direction. In the second direction, the minimum distance D between the bending edge line and the edge of the explosion-proof sheet 500 is D. The minimum distance D and the wall thickness t of the casing satisfy the relationship: D≥1.5t. Understandably, D represents the safe distance at the 500mm position of the explosion-proof plate. Insufficient minimum distance D can lead to structural deformation due to process conflicts during shell manufacturing, causing fluctuations in burst pressure. In thin-walled shell structures, the shell thickness t is fundamental to overall rigidity and pressure-bearing capacity, and it is highly sensitive to local deformation. As a key parameter, it directly affects stress transfer during welding and bending. Therefore, in the distance design model, a wall thickness correlation mechanism replaces fixed empirical values. The local stiffness of the thin-walled shell decreases as the thickness decreases. A stress attenuation zone is formed by controlling the distance to 1.5t, causing stress to gradually decrease along the shell plane. This avoids stress concentration during bending, which can lead to cracks or bending springback, eliminates the risk of deformation failure due to process conflicts, effectively reduces burst pressure fluctuations, improves shell pressure consistency, and dynamically adjusts the distance based on the wall thickness, avoiding redundant space occupation caused by fixed values.

[0031] Please see Figure 1 In one embodiment of this utility model, the shell is formed by bending a metal sheet and welding the seams together to form an integral structure. An explosion-proof hole is formed on the first surface 100 of the shell, and an explosion-proof sheet 500 covers the surface of the explosion-proof hole and is sealed by continuous welding. The explosion-proof sheet 500 is fixed to the first surface 100 through the first weld, forming an explosion-proof valve structure. The shell material is stainless steel, such as 304 stainless steel, and the wall thickness t is designed to be 0.2mm-0.5mm. Using steel as the base material, its high strength can maintain structural integrity under reduced wall thickness, thereby significantly improving the battery energy density. The reasonable design of the wall thickness range effectively saves space while ensuring the stability of bending. It should be noted that the material of the shell is not limited; when different materials are selected, the process parameters, etc., are adjusted accordingly.

[0032] Please see Figure 1In one embodiment of this utility model, the minimum distance D and the wall thickness t of the shell satisfy the relationship: D≥3t. In the manufacturing and processing of the shell, there are two optional processing paths: one is to first bend the sheet metal and weld it at the joint to form the shell as a whole, and then weld the explosion-proof sheet 500 at the explosion-proof hole position; the other is to pre-weld the explosion-proof sheet 500 at the explosion-proof hole position of the shell, then bend it according to the preset position and direction and weld it at the joint to form the shell as a whole. In the process of bending before welding, the welding heat input induces springback deformation in the bending area. The purpose of setting a minimum distance is mainly to prevent the welding heat input from causing springback deformation in the bent area, which would damage the stability of the bent plate shape and the structural stability of the explosion-proof sheet 500. In the process of welding before bending, the deformation of the plate during the subsequent bending process will generate significant tensile stress in the first weld area at the connection between the explosion-proof sheet 500 and the shell, thereby damaging the structural integrity and mechanical properties of the first weld or its heat-affected zone, and damaging the structure of the explosion-proof sheet 500. Therefore, a sufficient distance needs to be set to establish a stress buffer zone, keeping the weld area away from the bending deformation zone and protecting the strength of the weld area. Generally, the minimum distance D is designed to be ≥3t, which can effectively avoid the pulling of the weld heat-affected zone after bending plastic deformation.

[0033] Please see Figure 1 In one embodiment of this utility model, the maximum length of the explosion-proof sheet 500 in the first direction is L, and the maximum width in the second direction is W. In a specific embodiment, the first direction and the second direction are also the length direction and width direction of the shell. When L / W>4, the minimum distance D and the wall thickness t of the shell satisfy the relationship: D≥4t. The explosion-proof sheet 500 is, for example, a racetrack-shaped structure, whose outline includes two parallel long straight segments extending along the first direction and an arc segment connecting the two ends of the two long straight segments. The maximum length L is the distance between the two arc vertices in the first direction, and the maximum width is the distance between the two straight segments in the second direction. The aspect ratio (i.e., L / W) of the explosion-proof sheet 500 is directly related to the stress state, which determines the degree of stress concentration. When the aspect ratio is large, the rigidity of the explosion-proof sheet 500 is low, and stress concentration is likely to occur. When L / W>4, the bending stress is highly concentrated at the end of the explosion-proof sheet 500, and the edge distance design needs to be increased to D≥4t to disperse the stress gradient at the end and avoid deformation of the explosion-proof sheet 500.

[0034] Please see Figure 1In one embodiment of this utility model, the maximum length of the explosion-proof sheet 500 in the first direction is L, and the maximum width in the second direction is W. When L / W < 3, the minimum distance D and the wall thickness t of the shell satisfy the relationship: D ≥ 2t. When the length-to-width ratio of the explosion-proof sheet 500 is small, it has higher rigidity characteristics, its stress distribution shows a uniform trend, and local stress concentration is significantly reduced. Based on this mechanical characteristic, when L / W < 3, the minimum distance from the bending edge 410 to the edge of the explosion-proof sheet 500 is set to D ≥ 2t. This distance design suppresses the risk of structural deformation caused by process conflicts while optimizing the space utilization efficiency of the shell and avoiding distance redundancy.

[0035] Please see Figure 1 In one embodiment of this utility model, the maximum length of the explosion-proof sheet 500 in the first direction is L, and the maximum width in the second direction is W. The minimum distance D, the wall thickness t of the shell, and the maximum length L and maximum width W of the explosion-proof sheet 500 satisfy the following relationship: D min =K*t*(1+L / W), where K is a process parameter, and K takes a value of 1 to 2. In this distance control model, D... min That is, the minimum distance D between the bending edge 410 and the edge of the explosion-proof sheet 500, where the minimum distance D ≥ D min The minimum distance D plays a crucial role in the stress state, deformation, and safety of the shell and the explosion-proof sheet 500. During the design, the interaction and superposition of multiple influencing factors such as process sequence, explosion-proof sheet 500 geometry, and shell wall thickness are fully considered. A triple coupling mechanism is adopted to control the minimum distance D and establish a mathematical model that can cover various working conditions. It can effectively solve the problem of local stress concentration or structural deformation failure caused by process conflicts such as welding and bending, and ensure the stability of burst pressure.

[0036] Please see Figure 1Specifically, the wall thickness *t* of the shell body is fundamental to determining the overall rigidity and pressure-bearing capacity. Furthermore, *t* is highly sensitive to local deformation, directly affecting stress transfer during welding and bending processes. As a thin-wall sensitivity coefficient, *t* reflects the amplification effect of local deformation in thin-walled shells. The aspect ratio *L / W* directly relates to the stress state, determining the degree of stress concentration. A larger aspect ratio results in lower rigidity of the explosion-proof sheet 500, making stress concentration more likely. Conversely, a smaller aspect ratio results in higher rigidity, more uniform stress distribution, and less local stress concentration. The influence of the aspect ratio on stress distribution is quantified using the term (1+L / W). The variations in different processes... The stress state changes during welding and bending, thus affecting the minimum distance. This change in process is reflected in the process parameter K, which ranges from 1 to 2. Different K values ​​are set for different processes. For example, if welding precedes bending, the stress increases by 30%-50%, increasing the risk of stress concentration and cracking, requiring a larger minimum distance; in this case, K is set to 1.8. Conversely, if bending precedes welding, only the influence range of the welding heat-affected zone needs to be controlled; in this case, K is set to 1.2. The process coefficient K integrates the differences between processes, and appropriate process coefficients are used according to different processes. For example, if welding precedes bending, t = 0.25mm, L / W = 5, then D can be calculated. min =1.8*0.25*(1+5)=2.7mm, at this time the minimum distance D≥2.7mm; after the distance model is established, the feasibility of D is finally verified by substituting specific parameters to determine the stability and reliability of the model.

[0037] Please see Figure 1 In one embodiment of this utility model, the maximum length L and maximum width W of the explosion-proof sheet 500 satisfy the relationship: 3 ≤ L / W ≤ 8. The value of L / W, i.e., the length-to-width ratio, affects the structural rigidity. When L / W < 3, the structural rigidity is too high. min Redundancy in L / W ratio leads to wasted space. When L / W > 8, the structural rigidity is too low, causing stress concentration at the ends to exceed the material fatigue limit. Reasonable control of L / W can achieve an optimal balance between the uniformity of stress distribution and space utilization in the explosion-proof sheet. Preferably, the maximum length L and the maximum width W satisfy the relationship: 3 ≤ L / W ≤ 5.

[0038] Please see Figure 1In one embodiment of this utility model, the explosion-proof sheet 500 is fixed to the first surface 100 by a first weld. The first weld extends continuously along the outer periphery of the explosion-proof sheet 500, and a cryogenic strengthening zone is formed on the surface of the shell. The cryogenic strengthening zone is a strip-shaped area surrounding the first weld, extending outward from the boundary of the first weld and continuously along the trajectory of the first weld. It is understood that after welding, heat-affected zones are formed on both sides of the first weld. The material in the heat-affected zone undergoes significant changes in structure and properties due to the welding thermal cycle, making it the weakest link in the welded joint. Due to the reduced toughness and residual stress in this area, cracks are easily triggered and propagated during bending. Through process optimization, a cryogenic strengthening zone is formed on the first surface 100 after welding and before bending, ensuring that its coverage reaches the entire heat-affected zone through cryogenic treatment. This ensures that the microstructure of the heat-affected zone is improved, effectively enhancing its mechanical properties and preventing cracking caused by stress concentration during subsequent bending. The specific width of the cryogenic strengthening zone is determined according to the width of the weld heat-affected zone, ensuring that it covers the heat-affected zone.

[0039] Please see Figure 1 In one optional embodiment, the cryogenic strengthening zone is formed by cryogenic treatment with liquid nitrogen at a temperature of -196°C. Liquid nitrogen spraying refines the austenite grains, improves the material's toughness, and eliminates the risk of crack propagation caused by subsequent bending stress. It should be noted that when the shell material, thickness, etc., are different, the cryogenic parameters need to be dynamically adjusted according to the material properties.

[0040] Please see Figure 1 In one embodiment of this utility model, a stress relief zone is further provided on the first surface 100 between the bending edge 410 and the explosion-proof sheet 500. The stress relief zone is a strip-shaped area extending along the first direction, and the minimum distance between the stress relief zone and the bending edge 410 in the second direction is 1mm. In the process of bending before welding, after the shell is bent and formed, the explosion-proof sheet 500 is welded. Due to the residual stress near the bending area, the welding heat input causes the bending area to spring back. Through process optimization, after bending and before welding, an annealing treatment is performed in the area between the welding area and the bending area, i.e., between the bending edge 410 and the explosion-proof sheet 500, to form a stress relief zone, eliminating the uneven residual stress after bending and avoiding bending springback caused by heat during subsequent welding. Since the heat-affected zone of welding is a gradual conduction process, it is only necessary to set a buffer zone on the path and control the starting point of the annealing zone to be set at 1 mm away from the bending edge 410 and extend it to the welding area. This effectively prevents the bending zone from springing and deforming due to heat conduction, while avoiding damage to the strength of the bending zone.

[0041] Please see Figure 1In an optional embodiment, the stress relief zone is formed by laser annealing, wherein the power density of the laser annealing is ≤50W / mm². 2 Laser annealing allows for precise control, avoiding unnecessary thermal impact on the overall structure and helping to maintain component stability, while controlling the power density value P ≤ 50W / mm². 2 This ensures the removal of residual stress while avoiding material damage caused by excessively high power density. It should be noted that when the material and thickness of the casing vary, the power density parameters need to be dynamically adjusted based on the material properties.

[0042] Please see Figure 1 In one optional embodiment, the shell employs a welding-then-bending process. First, an explosion-proof sheet 500 is welded onto a flat stainless steel plate. The first weld seam forms a closed loop along the contour of the explosion-proof sheet 500, achieving fixation and sealing of the explosion-proof sheet 500 on the shell surface. Subsequently, a -196℃ liquid nitrogen cryogenic treatment is performed to form a cryogenic strengthening zone in the weld heat-affected zone, improving material toughness. Finally, bending and seam welding are performed. The minimum distance D between the edge of the explosion-proof sheet 500 and the preset bending edge line 410 is set according to D. min =1.8*t*(1+L / W) design, for example, when t=0.25mm and L / W=5, D≥2.7mm. The distance model, combined with the cryogenic treatment process, causes the bending stress to attenuate to a safe threshold before being transmitted to the first weld, completely eliminating the risk of cracking in the heat-affected zone and effectively reducing the fluctuation of burst pressure.

[0043] Please see Figure 1 In another optional embodiment, the shell adopts a bending-then-welding process. First, the stainless steel sheet is bent into shape and then welded together to form a cylindrical structure. Subsequently, laser annealing is performed between the bending area and the welding area to form a stress-relieving zone. The laser annealing power density is ≤50W / mm². 2 The edge of the annealed zone is approximately 1 mm from the bending edge 410. Annealing is used to reduce the local yield strength. Finally, an explosion-proof sheet 500 is welded. The minimum distance D between the explosion-proof sheet 500 and the bending edge 410 is specified by D. min =1.2*t*(1+L / W) control. By using the annealed strip as a thermal stress buffer layer, the springback deformation in the bending zone is effectively reduced, and the geometric accuracy of the shell is improved.

[0044] Please see Figure 1This utility model also proposes a battery, including a battery casing, electrode assembly, and cover plate as described in any of the above embodiments. The battery casing is a structure with an internal cavity formed by bending a sheet metal and connecting it with a second weld. At least one end of the battery casing has an opening. It is understood that the battery casing can be formed by bending the sheet metal once or multiple times and welding it at the joints. The electrode assembly is disposed inside the battery casing, and the cover plate is sealed and welded to the opening of the battery casing. An explosion-proof hole is provided on the first surface 100 of the battery casing. The welding position of the explosion-proof plate 500 is designed according to a distance model. The explosion-proof plate 500 is fixed to the surface of the casing through the second weld and seals the explosion-proof hole. Through the synergistic optimization of the distance model between the thin-walled steel casing and the explosion-proof plate, the battery energy density is improved, and the risk of thermal diffusion is significantly reduced.

[0045] In summary, the battery casing and battery of this invention dynamically correlate the minimum distance between the explosion-proof plate 500 and the bending edge 410 with the casing wall thickness, ensuring physical isolation between the bending plastic deformation zone and the welding heat-affected zone, effectively eliminating the deformation risk caused by process sequence selection, and reducing burst pressure fluctuations. A precise distance model is established through a triple coupling mechanism integrating wall thickness, aspect ratio, and process differences, combined with process optimization targeting weak areas, significantly reducing the deformation failure risk of the casing and explosion-proof plate 500, suppressing burst pressure fluctuations, and possessing wide adaptability to various operating conditions. Through the design of the aspect ratio of the explosion-proof plate 500, an optimized balance is achieved between stress distribution uniformity and casing space utilization efficiency. The distance design mathematical model enables precise control of the welding position of the explosion-proof plate 500 on a thin-walled steel casing, fundamentally solving the problems of deformation, cracking, and burst pressure fluctuations caused by conflicts between bending and welding processes in thin-walled steel casings. This achieves synergistic adaptation between the casing structure and manufacturing process, ensuring the structural reliability of the casing and explosion-proof valve, and simultaneously improving battery energy density and safety reliability.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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”.

[0052] 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.

[0053] 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.

[0054] 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 first surface and a second and a third surface that are adjacent to the first surface and located on opposite sides of the first surface; The first surface is connected to the second surface and the third surface through a bent surface. The bent surface is a transition surface between the first surface and the second surface and between the first surface and the third surface. A bent edge line is formed at the connection position between the bent surface and the first surface. An explosion-proof sheet is provided on the first surface. In the plane of the first surface, the bending edge extends along the first direction, and the second direction is perpendicular to the first direction. The minimum distance between the bending edge and the edge of the explosion-proof sheet in the second direction is D. The minimum distance D and the wall thickness t of the shell satisfy the relationship: D≥1.5t.

2. The battery casing according to claim 1, characterized in that, The minimum distance D and the wall thickness t of the shell satisfy the following relationship: D≥3t.

3. The battery casing according to claim 1, characterized in that, The maximum length of the explosion-proof sheet in the first direction is L, and the maximum width in the second direction is W. When L / W>4, the minimum distance D and the wall thickness t of the shell satisfy the relationship: D≥4t.

4. The battery casing according to claim 1, characterized in that, The maximum length of the explosion-proof sheet in the first direction is L, and the maximum width in the second direction is W. When L / W < 3, the minimum distance D and the wall thickness t of the shell satisfy the relationship: D ≥ 2t.

5. The battery casing according to claim 1, characterized in that, The explosion-proof sheet has a maximum length of L in the first direction and a maximum width of W in the second direction; The minimum distance D, the wall thickness t of the shell, and the maximum length L and maximum width W of the explosion-proof sheet satisfy the following relationship: D min =K*t*(1+L / W), where K takes values ​​from 1 to 2.

6. The battery casing according to claim 5, characterized in that, The maximum length L and maximum width W of the explosion-proof sheet satisfy the following relationship: 3≤L / W≤8.

7. The battery casing according to claim 6, characterized in that, The maximum length L and maximum width W of the explosion-proof sheet satisfy the following relationship: 3≤L / W≤5.

8. The battery casing according to claim 1, characterized in that, The explosion-proof sheet is fixed to the first surface by a first weld, which extends continuously along the outer periphery of the explosion-proof sheet. A cryogenic strengthening zone is also formed on the surface of the shell. The cryogenic strengthening zone is a strip-shaped area surrounding the first weld, which extends outward from the boundary of the first weld and extends continuously along the trajectory of the first weld.

9. The battery casing according to claim 1, characterized in that, On the first surface, a stress relief area is provided between the bending edge and the explosion-proof sheet. The stress relief area is a strip-shaped area extending along the first direction. In the second direction, the minimum distance between the stress relief area and the bending edge is 1 mm.

10. A battery, characterized in that, include: The battery housing as described in any one of claims 1-9 is a structure with an internal cavity formed by bending a sheet metal and connecting it with a second weld, and at least one end of the battery housing is provided with an opening; Electrode assembly, disposed within the battery casing; A cover plate, which is sealed and welded to the opening of the battery casing.

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