Battery shell and battery

Abstract

The invention relates to the technical field of batteries, and discloses a battery shell and a battery. The battery case includes: a case having an opening; the cover plate seals the opening to form a containing cavity, the cover plate comprises a cover plate body and a folded edge arranged on the edge of the cover plate body, the folded edge extends in the direction away from the containing cavity and is welded to the shell, a welding area is formed at the welding position of the folded edge and the shell, and in the extending direction of the folded edge, the cover plate body is located on the side, close to the containing cavity, of the welding area. In the direction perpendicular to the upper surface of the cover plate body, the distance between the side, close to the containing cavity, of the welding area and the upper surface of the cover plate body is h, the distance between the side, away from the containing cavity, of the folded edge and the side, close to the containing cavity, of the cover plate body is H, and h / H is larger than or equal to 0.17 and smaller than or equal to 0.5. The cover plate can play a buffering role, and the cover plate is prevented from being separated from the shell during thermal runaway; meanwhile, the overall height of the cover plate can be controlled, and the internal space of the shell is ensured, so that the energy density of the single battery is ensured.

Description

[0001] This application is a divisional application of the invention patent application with publication number CN119050563A. The application date of the original application is: 2024.10.28; the application number is: 202411506503.6; the name of the invention is: battery casing and battery. Technical Field

[0002] The present invention relates to the technical field of batteries, and in particular to a battery casing and a battery. Background Art

[0003] As lithium-ion battery technology matures, lithium-ion batteries are increasingly used as power batteries in electric vehicles and energy storage. Lithium-ion battery packs usually include multiple batteries, and existing batteries are generally divided into cylindrical batteries, soft-pack batteries, and square batteries.

[0004] The existing square battery includes a battery casing and a battery cell arranged in the battery casing. The battery casing includes a shell and a cover plate. The shell and the cover plate are fixed together by welding. The welding position of the shell and the cover plate is easily damaged when the battery has thermal runaway, causing the entire cover plate to detach from the shell, which will further cause thermal runaway of other batteries, and may cause the battery pack to catch fire and explode, posing a major safety hazard. Summary of the invention

[0005] In view of this, the present invention provides a battery casing and a battery to solve the problem that the welding position between the casing and the cover plate is easily damaged when the battery is in thermal runaway, causing the cover plate to separate from the casing.

[0006] In the first aspect, the present invention provides a battery shell, comprising: a shell having an opening; a cover plate, sealing the opening to form a accommodating cavity, the cover plate comprising a cover plate body and a folded edge arranged at the edge of the cover plate body, the folded edge extending in a direction away from the accommodating cavity, the folded edge welded to the shell, and the welded portion of the folded edge and the shell forms a welding area, in the extending direction of the folded edge, the cover plate body is located on the side of the welding area close to the accommodating cavity, in the direction perpendicular to the upper surface of the cover plate body, the side of the welding area close to the accommodating cavity is at a distance h from the upper surface of the cover plate body, and the distance from the side of the folded edge away from the accommodating cavity to the side of the cover plate body close to the accommodating cavity is H, wherein 0.17≤h / H≤0.5; the cover plate body and the folded edge are connected by an arc transition portion, and the arc radius R and h of the arc transition portion satisfy the relationship: 0.5mm≤R+h≤1mm.

[0007] In a second aspect, the present invention further provides a battery, comprising: the above-mentioned battery casing, and a battery cell, wherein the battery cell is arranged in a receiving cavity of the battery casing.

[0008] Beneficial effect: The folded edges of the shell and the cover are fixed together by welding. If the ratio of h to H is too small, when the cover body is subjected to force, the force will be quickly transmitted to the weld, causing the weld to crack, and it will not be able to play a buffering role. The buffering effect is weakened, and the cover is easy to separate from the shell during thermal runaway, posing a major safety hazard; if the ratio of h to H is too large, the space inside the shell where the cover is located is larger, which in turn affects the energy density of the single cell, thereby affecting the capacity of the battery.

[0009] The ratio of h to H is in the range of 0.17 to 0.5, which can ensure that the cover plate can play a buffering role and prevent the cover plate from separating from the shell during thermal runaway. It can also solve the problem that the welding position between the shell and the cover plate is easily damaged during thermal runaway of the battery, causing the cover plate to separate from the shell. At the same time, it can control the overall height of the cover plate to ensure the internal space of the shell, thereby ensuring the energy density of the single battery.

[0010] The arc-shaped transition portion can improve the buffering performance. When the relationship is satisfied, it can not only ensure the welding strength between the shell and the folded edge, but also ensure the buffering performance, prevent the cover plate from separating from the shell during thermal runaway, and reduce the distance between the welding area and the cover plate body, indirectly reducing the distance that the cover plate enters the interior of the shell, ensuring the space size of the accommodating cavity for accommodating the battery cell, and ensuring the capacity of the single battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0012] Figure 1 A three-dimensional diagram of a battery housing according to an embodiment of the present invention;

[0013] Figure 2 for Figure 1 A top view of the battery housing shown;

[0014] Figure 3 for Figure 2 AA sectional view of the battery casing shown;

[0015] Figure 4 for Figure 3 A partial enlarged schematic diagram of B in the figure.

[0016] Description of reference numerals:

[0017] 1. Shell;

[0018] 2. Cover plate; 201. Cover plate body; 202. Folded edge; 203. Transition part; 204. Welding area. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0020] Combine the following Figures 1 to 4 , describing an embodiment of the present invention.

[0021] According to an embodiment of the present invention, on the one hand, a battery shell is provided, comprising: a shell 1 and a shell 1, the shell 1 having an opening; a cover plate 2 sealing the opening to form a accommodating cavity, the cover plate 2 comprising a cover plate body 201 and a folded edge 202 arranged at the edge of the cover plate body 201, the folded edge 202 extending in a direction away from the accommodating cavity, the folded edge 202 is welded to the shell 1, and the welded portion of the folded edge 202 and the shell 1 forms a welding area 204, in the extension direction of the folded edge 202, the cover plate body 201 is located on the side of the welding area 204 close to the accommodating cavity, in the direction perpendicular to the upper surface of the cover plate body 201, the side of the welding area 204 close to the accommodating cavity is at a distance h from the upper surface of the cover plate body 201, and the distance from the side of the folded edge 202 away from the accommodating cavity to the side of the cover plate body 201 close to the accommodating cavity is H, wherein 0.17≤h / H≤0.5.

[0022] In the battery casing of the present embodiment, the folded edge 202 of the shell 1 and the cover 2 are fixed together by welding. If the ratio of h to H is too small, when the cover body 201 is subjected to force, the force will be quickly transmitted to the weld, causing the weld to crack, and the buffering effect will be unable to be played. The buffering effect is weakened, and the cover is easy to separate from the shell during thermal runaway, posing a major safety hazard; if the ratio of h to H is too large, the space inside the shell where the cover is located is larger, which in turn affects the energy density of the single cell, thereby affecting the capacity of the battery.

[0023] Therefore, when the ratio of h to H is within the range of 0.17 to 0.5, the cover plate 2 can play a buffering role and prevent the cover plate 2 from separating from the shell 1 during thermal runaway, and to a certain extent solve the problem that the welding position between the shell 1 and the cover plate 2 is easily damaged during thermal runaway of the battery, resulting in the cover plate 2 separating from the shell 1; at the same time, the overall height of the cover plate 2 can be controlled to ensure the internal space of the shell 1, thereby ensuring the energy density of the single battery.

[0024] Specifically, the ratio of h / H may preferably be 0.2, 0.25, 0.3, 0.35, 0.4 or 0.45.

[0025] Furthermore, the range of H is 0.5 mm to 4 mm. If H is larger, it means that the overall height of the cover plate 2 is higher, and the cover plate 2 occupies a larger space inside the shell 1, which in turn affects the energy density of the single battery, thereby affecting the capacity of the battery. If H is smaller, it means that the overall height of the cover plate 2 is lower, making the welding area 204 smaller, and the welding between the folded edge 202 and the shell 1 is not firm, and the cover plate 2 is easy to separate from the shell 1 when the cover plate 2 is subjected to force, which poses a greater safety hazard.

[0026] Therefore, when H is within the range of 0.5 mm to 4 mm, it not only ensures that the folded edge 202 is firmly welded to the shell 1, but also controls the space occupied by the cover plate 2 to ensure the energy density of the battery.

[0027] Specifically, H may preferably be 1 mm, 1.5 mm, 1.6 mm, 1.8 mm, 2 mm, 2.2 mm, 2.5 mm, 3 mm, 3.2 mm, 3.5 mm or 3.8 mm.

[0028] In one embodiment, h is in the range of 0.1 mm to 1 mm. If h is too large, the height of the cover plate 2 is high, and the cover plate 2 occupies a large space in the shell 1, which greatly affects the height of the battery cell inside the shell 1, thereby affecting the capacity of the battery; if h is too small, when the cover plate body 201 is subjected to force, the force will be quickly transmitted to the weld, causing the weld to crack, and it will not play a buffering role, and the cover plate 2 will easily separate from the shell 1 in the event of thermal runaway.

[0029] Therefore, h is set within the range of 0.1mm to 1mm, that is, h is within a suitable range, and the height of the cover plate 2 is within a suitable range, which can reduce the impact on the capacity of the battery cell and play a buffering role. The cover plate 2 is not easily separated from the shell 1 during thermal runaway, and can solve the problem that the welding position of the shell 1 and the cover plate 2 is easily damaged during thermal runaway of the battery, causing the cover plate 2 to separate from the shell 1 to a certain extent.

[0030] Specifically, h may preferably be 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.55 mm, 0.6 mm, 0.65 mm, 0.7 mm, 0.8 mm or 0.9 mm.

[0031] In one embodiment, Figure 4 As shown, the ratio of the thickness T1 of the folded edge 202 to the thickness T2 of the shell 1 is 1.2:1 to 3:1. The thickness of the folded edge 202 refers to the distance between the inner side and the outer side of the folded edge 202, that is, Figure 4 The transverse dimension of the middle fold 202, the thickness of the shell 1 refers to the distance between the inner surface and the outer surface of the shell 1, that is, Figure 4 The lateral dimension of the housing 1.

[0032] Furthermore, if the ratio of the thickness T1 of the folded edge 202 to the thickness T2 of the shell 1 is too small, there is a greater risk of welding through the folded edge 202 during welding, which affects the seal and also reduces the mechanical strength of the welding part, which can easily cause the battery to be damaged when subjected to external force during use; if the ratio of the thickness T1 of the folded edge 202 to the thickness T2 of the shell 1 is too large, the welding power will increase, which will make it difficult to control the welding area 204, affecting the buffering performance.

[0033] Therefore, when the ratio of the thickness T1 of the folded edge 202 to the thickness T2 of the shell 1 is in the range of 1.2:1 to 3:1, the welding strength of the shell 1 and the cover plate 2 is good after welding, ensuring the sealing performance, and it is also convenient to control the welding area 204 to ensure the buffering performance.

[0034] Specifically, the ratio of the thickness T1 of the folded edge 202 to the thickness T2 of the shell 1 may preferably be 1.5:1, 1.8:1, 2:1, 2.2:1 or 2.5:1.

[0035] Furthermore, the thickness of the shell 1 at the opening ranges from 0.1mm to 0.5mm. If the shell 1 is thicker, the overall weight of the battery will increase, which will in turn affect the weight of the electric vehicle. A thicker shell 1 requires more materials, which will increase manufacturing costs and take up more space, and may not be suitable for space-constrained application scenarios. If the shell 1 is thinner, it is not as strong as a thicker shell 1 in terms of mechanical strength, and is easily deformed or damaged by external forces. A thinner shell 1 has a weaker ability to protect the battery cell, and may not be able to effectively prevent damage to the battery cell caused by external impact or extrusion.

[0036] Therefore, the thickness of the shell 1 at the opening is within the range of 0.1 mm to 0.5 mm, which can ensure the strength of the shell 1 while controlling the material cost, manufacturing cost, and occupied space.

[0037] Specifically, the thickness of the shell 1 at the opening may preferably be 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm or 0.48 mm.

[0038] Furthermore, the thickness of the folded edge 202 ranges from 0.2 mm to 0.9 mm. If the thickness of the folded edge 202 is too small, the folded edge 202 is easily welded through to form welding slag during the welding process between the shell 1 and the folded edge 202, which affects the safety of the battery. If the thickness of the folded edge 202 is too thick, the thicker folded edge 202 will increase the amount of material used, resulting in an increase in the overall weight of the cover plate 2. The thicker folded edge 202 requires more material, which will increase the manufacturing cost.

[0039] Therefore, the thickness of the folded edge 202 is within the range of 0.2 mm to 0.9 mm, which ensures the welding strength between the shell 1 and the cover plate 2 after welding, has good sealing performance, and can also facilitate the control of material consumption and cost.

[0040] Specifically, the thickness of the folded edge 202 may preferably be 0.3 mm, 0.4 mm, 0.5 mm, 0.55 mm, 0.6 mm, 0.65 mm, 0.7 mm or 0.8 mm.

[0041] In one embodiment, Figure 4 As shown, the top of the opening of the shell 1 is not higher than the top of the folded edge 202, that is, the top of the opening of the shell 1 is lower than the top of the folded edge 202, or the top of the opening of the shell 1 is flush with the top of the folded edge 202. Such a design can facilitate the positioning of the cover plate 2 during the installation process and improve the assembly efficiency.

[0042] Preferably, the top end of the opening of the shell 1 is lower than the top end of the folded edge 202 , so that during the assembly process of the cover plate 2 , the positioning effect of the cover plate 2 is better, reducing the difficulty of assembly.

[0043] In one embodiment, 0.17≤h / H≤0.35. When the top of the opening of the shell 1 is lower than the top of the folded edge 202, a welding area 204 needs to be reserved, so the value of h needs to be reduced to meet the welding strength requirements, thereby improving the reliability of the battery, and ensuring better sealing of the welding part to prevent liquid or gas leakage.

[0044] In one embodiment, Figure 4 As shown, the cover body 201 and the folded edge 202 are connected by an arc-shaped transition portion 203, and the arc radius R and h of the arc-shaped transition portion 203 satisfy the relationship: 0.5mm≤R+h≤1mm. The arc radius R of the arc-shaped transition portion 203 refers to the arc radius of the arc-shaped transition portion 203 connecting the cover body 201 and the folded edge 202 on the side of the cover 2 away from the accommodating cavity.

[0045] Furthermore, when R+h is too small, the buffering performance is poor, and the cover plate 2 is easily separated from the shell 1 during thermal runaway; when R+h is too large, the distance that the cover plate 2 enters the shell 1 is too large, resulting in a smaller cavity space inside the shell 1 for accommodating the battery cell, thereby reducing the energy density of the single battery.

[0046] Therefore, the arc-shaped transition portion 203 can improve the buffering performance. When the relationship is satisfied, it can not only ensure the welding strength between the shell 1 and the folded edge 202, but also ensure the buffering performance, prevent the cover plate 2 from separating from the shell 1 during thermal runaway, and reduce the distance between the welding area 204 and the cover plate body 201, indirectly reducing the distance that the cover plate 2 enters the interior of the shell 1, ensuring the space size of the accommodating cavity for accommodating the battery cell, and ensuring the capacity of the single battery.

[0047] Specifically, R+h may preferably be 0.6 mm, 0.7 mm, 0.75 mm, 0.8 mm, 0.85 mm or 0.9 mm.

[0048] In one embodiment, the arc radius R is in the range of 0.2 mm to 0.8 mm. If the arc radius R is too large, the overall height of the cover plate 2 is high and the space occupied is large; if the arc radius R is too small, the intersection of the folded edge 202 and the cover plate body 201 is similar to a right angle, and stress concentration is easily generated at the intersection of the folded edge 202 and the cover plate body 201, which reduces the structural strength of the cover plate 2 and affects the life and stability of the cover plate 2.

[0049] Therefore, the arc radius R is within the range of 0.2 mm to 0.8 mm, which can not only control the space occupied by the cover plate 2 , but also avoid stress concentration and improve the structural strength of the cover plate 2 .

[0050] Specifically, the arc radius R may preferably be 0.3 mm, 0.4 mm, 0.55 mm, 0.5 mm, 0.6 mm, 0.65 mm, 0.7 mm or 0.75 mm.

[0051] In one embodiment, the thickness of the arcuate transition portion 203 is 90% to 99% of the thickness of the folded edge 202. The arcuate transition portion 203 is designed to be thinner to facilitate the forming of the folded edge 202, reduce the processing difficulty and cost, and further play a buffering role to improve the structural stability.

[0052] Further, the thickness of the arc-shaped transition portion 203 ranges from 0.35 mm to 0.55 mm. The thickness of the arc-shaped transition portion 203 may preferably be 0.4 mm, 0.45 mm, 0.45 mm or 0.5 mm.

[0053] In one embodiment, Figure 4 As shown, the welding area 204 of the shell 1 and the folded edge 202 is spaced from the arc-shaped transition portion 203, that is, the welding area 204 does not overlap with the transition portion 203. There is a gap between the arc-shaped transition portion 203 and the shell 1. In order to ensure the welding quality, the welding area 204 and the arc-shaped transition portion 203 are spaced, thereby ensuring the welding reliability between the shell 1 and the cover plate 2 and the overall structural strength.

[0054] In one embodiment, a pole is provided on the cover plate 2, and 0.20≤h / H≤0.5. When a pole is provided on the cover plate 2, the minimum value of h should be increased to reduce the influence of welding heat on the pole, thereby ensuring the reliability of the connection between the pole and other components, and also avoiding poor contact of the pole due to thermal deformation, thereby ensuring the stability of the electrical connection and improving the reliability of the electrical connection.

[0055] In one embodiment, an explosion-proof valve is provided on the cover plate 2, and 0.23≤h / H≤0.5. When an explosion-proof valve is provided on the cover plate 2, the minimum value of h should be increased to reduce the influence of welding heat on the explosion-proof valve, thereby reducing the risk of damage to the explosion-proof valve due to overheating, ensuring that the explosion-proof valve can work normally in an emergency, avoiding the degradation of material properties due to thermal stress, and reducing the risk of failure of the explosion-proof valve.

[0056] In one embodiment, an explosion-proof valve and a pole are provided on the cover plate 2, and 0.25≤h / H≤0.5. When a pole and an explosion-proof valve are provided on the cover plate 2, the minimum value of h is increased, which is greater than the minimum value of h when a pole or an explosion-proof valve is provided alone, so that the influence of welding heat on the pole and the explosion-proof valve can be reduced, which not only ensures the reliability of the connection between the pole and other components, but also ensures that the explosion-proof valve can work normally in an emergency.

[0057] In one embodiment, the ratio of the sum of the heights h1 and h of the welding area 204 to the height h2 of the housing 1 is 0.002-0.05. The height h1 of the welding area 204 refers to the distance from the side of the welding area 204 away from the accommodating cavity to the side facing the accommodating cavity, that is, Figure 4 The vertical dimension of the welding area 204, the height of the shell 1 refers to the distance from the top to the bottom of the shell 1, that is, Figure 3 The vertical dimension of the middle shell 1.

[0058] In order to ensure the welding strength between the cover plate 2 and the shell 1, the welding area 204 needs to be limited. To ensure the welding strength, the welding area 204 cannot be too small, and in order to improve the strength of the cover plate 2 and the shell 1, the range of h cannot be too small. At the same time, considering that the cover plate body 201 extends into the interior of the shell 1, the height of the welding area 204 and the total length of h cannot be too long. Too long will lead to a reduction in the internal space of the shell 1, affecting the capacity of the battery.

[0059] Therefore, the ratio of the sum of the heights h1 and h of the welding area 204 to the height h2 of the shell 1 is in the range of 0.002 to 0.05, which not only ensures the welding strength between the cover plate 2 and the shell 1, but also makes the welding and fixing of the cover plate 2 and the shell 1 more firm and reliable. The cover plate 2 is not easy to separate from the shell 1 during thermal runaway, thereby reducing safety hazards and reducing the impact on the capacity of the battery cell.

[0060] Specifically, the ratio of the sum of the heights h1 and h of the welding area 204 to the height h2 of the shell 1 may preferably be 0.004, 0.006, 0.008, 0.01, 0.015, 0.02, 0.025, 0.03, 0.035, 0.04 or 0.045.

[0061] Furthermore, the height h2 of the shell 1 ranges from 80 mm to 250 mm. The height h2 of the shell 1 should not be too high or too low. If the height h2 of the shell 1 is too high, the higher shell 1 will increase the overall weight, which may have an adverse effect on the user experience of the portable device and may not be suitable for application scenarios with strict size requirements; if the height h2 of the shell 1 is too low, the lower shell height means that the electrode material that can be loaded is limited, thereby limiting the maximum capacity of the battery. A lower shell may cause the internal space to be too compact, affecting the heat dissipation effect, and further affecting the performance and life of the battery. A shell that is too low may weaken its mechanical strength, making the battery more susceptible to external physical damage. A lower shell limits the flexibility of the internal design, and it may be difficult to optimize the internal structure of the battery to achieve optimal performance.

[0062] Therefore, the height of the shell 1 is within the range of 80 mm to 250 mm, which can control the weight of the shell and be suitable for application scenarios with strict requirements on size, while also ensuring the capacity and mechanical strength of the battery and optimizing the internal structure of the battery.

[0063] Specifically, the height of the housing 1 may preferably be 90 mm, 100 mm, 110 mm, 120 mm, 130 mm, 140 mm, 145 mm, 150 mm, 155 mm, 160 mm, 165 mm, 170 mm, 180 mm, 200 mm, 220 mm or 240 mm.

[0064] In one embodiment, the welding area 204 of the folded edge 202 and the shell 1 is located on the surface of the shell 1. The folded edge 202 and the shell 1 are fixed by penetration welding, which penetrates from the surface of the shell 1 to the folded edge 202 for welding. Penetration welding has the advantages of high-strength connection, good sealing, wide applicability, and high welding quality.

[0065] Furthermore, the welding area 204 does not penetrate the folded edge 202. The welding area 204 does not penetrate the folded edge 202, which can reduce the fine holes or cracks caused by full penetration welding, thereby improving the sealing of the battery, preventing electrolyte leakage or external contaminants from entering the battery, and reducing the risk of leakage. Incomplete penetration welding retains the integrity of the material and avoids the material weakening that may occur during full penetration welding, thereby maintaining the structural strength of the housing 1 and the cover plate 2, and can also reduce stress concentration and improve the fatigue resistance of the welding area 204.

[0066] It should be noted that the welding area 204 is Figure 4 The gray area in .

[0067] It is understandable that, in another embodiment, the folded edge 202 and the shell 1 may also be butt-welded.

[0068] In one embodiment, Figure 4 As shown, the maximum depth D of the welding area 204 on the hem 202 accounts for 0.2 to 0.9 of the thickness T of the hem 202 and the total thickness of the shell 1. The depth of the welding area 204 on the hem 202 refers to the depth of the melting inside the hem along the thickness direction of the hem during welding, and the melting depth can also be referred to as the penetration depth.

[0069] Furthermore, when welding the cover body and the shell 1, if the maximum depth of the welding area 204 on the folded edge 202 accounts for a large ratio of the thickness of the folded edge 202 to the total thickness of the shell 1, it means that the welding area 204 extends into the folded edge 202 to a deeper depth, resulting in a significant weakening of the strength of the welding area 204, which is likely to cause local stress concentration and destroy the structural integrity of the welding area 204. If the maximum depth of the welding area 204 on the folded edge 202 accounts for a small ratio of the thickness of the folded edge 202 to the total thickness of the shell 1, it means that the welding area 204 extends into the folded edge 202 to a shallower depth, resulting in insufficient strength of the welding area 204, thereby affecting the overall stability and safety of the structure.

[0070] Therefore, the ratio of the maximum depth D of the welding area 204 on the folded edge 202 to the thickness T of the total thickness of the folded edge 202 and the shell 1 is in the range of 0.2 to 0.9, that is, the depth of the welding area 204 extending into the folded edge 202 is in an appropriate range, ensuring the strength of the welding area 204 and improving the integrity and safety of the structure.

[0071] Further, when the maximum depth D of the welding area 204 on the folded edge 202 accounts for a total thickness range of the thickness T2 of the shell 1 and the thickness of the folded edge 202 within a certain range, the preferred range of h+h1 is 1.2 mm to 2.0 mm.

[0072] It is worth noting that the height direction of the housing 1 refers to Figure 3 In the up-down direction, the depth direction of the welding area 204 is the thickness direction of the folded edge 202.

[0073] It should be noted that the thickness of the folded edge 202 can be equal to the thickness of the cover body 201, or can be less than or equal to the thickness of the cover body 201. The thickness of the folded edge 202 and the thickness of the cover body 201 need to be set according to specific circumstances.

[0074] In one embodiment, the battery shell is made of stainless steel, that is, the cover plate 2 and the shell 1 are both made of stainless steel. Stainless steel has the advantages of good corrosion resistance, high strength, excellent thermal expansion performance and thermal insulation performance, good impermeability, good safety, and weldability.

[0075] It is understandable that in another embodiment, the battery housing may be made of other materials, and is not limited thereto.

[0076] In one embodiment, the cover plate body 201 and the folded edge 202 are formed by bending a plate, and the cover plate 2 is processed by the plate, which is simple to process and reduces the manufacturing cost. If the thickness of the plate is consistent at all places, the thickness of the folded edge 202 formed by bending the edge of the plate is the same as the thickness of the cover plate body 201. If the thickness of the plate is gradually changed, the thickness of the folded edge 202 is different from the thickness of the cover plate body 201.

[0077] It is understandable that, in another embodiment, the cover body 201 and the folded edge 202 may also be formed separately and fixedly connected.

[0078] In one embodiment, the folded edge 202 is arranged around the cover body 201, and the folded edge 202 is interference fit with the inner wall of the shell 1, so that the shell 1 and the cover 2 can be welded together conveniently by penetration welding, thereby improving welding efficiency.

[0079] According to an embodiment of the present invention, on the other hand, a battery is provided, comprising: the above-mentioned battery casing, and a battery cell, wherein the battery cell is arranged in a receiving cavity of the battery casing.

[0080] Furthermore, the battery cell may be a wound battery cell or a laminated battery cell, the pole may be arranged on the battery housing or on the cover body 201, and the pole and the lug of the battery cell are connected together through a connecting sheet.

[0081] It should be noted that the battery cells, poles, etc. can all adopt the structures in the prior art, which will not be described in detail here.

[0082] According to another aspect of an embodiment of the present invention, a battery pack is provided, comprising: the above-mentioned battery.

[0083] Furthermore, a battery pack combines multiple batteries and their related components to form a complete energy storage unit. The design and structural composition of a battery pack usually need to consider multiple factors, including but not limited to safety, reliability, thermal management, electrical connections, etc.

[0084] Specifically, the battery pack also includes a battery box, a battery management system, a thermal management system, etc. The battery box is used to hold the battery. The battery management system is responsible for monitoring the battery status, such as voltage, current, temperature, etc., and managing it to ensure the battery is safe and efficient. It can also achieve battery balancing to prevent individual batteries from being overcharged or over-discharged. The thermal management system is used to maintain the battery pack within an optimal operating temperature range, usually achieved through a cooling or heating system, which helps to improve battery life and safety.

[0085] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A battery casing, characterized in that: include: A housing (1) having an opening; A cover plate (2) is sealed at the opening to form a receiving cavity, the cover plate (2) comprising a cover plate body (201) and a folded edge (202) arranged at the edge of the cover plate body (201), the folded edge (202) extending in a direction away from the receiving cavity, the folded edge (202) being welded to the shell (1), a welding area (204) being formed at a location where the folded edge (202) and the shell (1) are welded, and in the extending direction of the folded edge (202), the cover plate body (201) is located on a side of the welding area (204) close to the receiving cavity, in a direction perpendicular to the upper surface of the cover plate body (201), a distance h from a side of the welding area (204) close to the receiving cavity to the upper surface of the cover plate body (201), and a distance H from a side of the folded edge (202) away from the receiving cavity to a side of the cover plate body (201) close to the receiving cavity, wherein 0.17≤h / H≤0.5; The cover plate body (201) and the folded edge (202) are connected via an arc-shaped transition portion (203), and the arc radius R of the arc-shaped transition portion (203) and h satisfy the relationship: 0.5mm≤R+h≤1mm.

2. The battery housing according to claim 1, characterized in that: The range of h is 0.2 mm to 0.9 mm.

3. The battery housing according to claim 1, characterized in that: The ratio of the thickness T1 of the folded edge (202) to the thickness T2 of the shell (1) is 1.2:1 to 3:

1.

4. The battery housing according to claim 1, characterized in that: The arc radius R ranges from 0.2 mm to 0.8 mm.

5. The battery housing according to claim 1, characterized in that: The thickness of the arc-shaped transition portion (203) is 90% to 99% of the thickness of the folded edge (202).

6. The battery housing according to claim 5, characterized in that: The thickness of the arc-shaped transition portion (203) ranges from 0.35 mm to 0.55 mm.

7. The battery housing according to claim 1, characterized in that: The welding area (204) between the shell (1) and the folded edge (202) is arranged at intervals from the arc-shaped transition portion (203).

8. The battery housing according to claim 1, characterized in that: The ratio of the sum of the height h1 of the welding area (204) and h to the height h2 of the shell (1) is 0.002-0.

05.

9. The battery housing according to claim 1, characterized in that: The welding area (204) between the folded edge (202) and the shell (1) is located on the surface of the shell (1).

10. A battery, characterized in that: include: A battery casing as claimed in any one of claims 1 to 9, and a battery cell, wherein the battery cell is arranged in a receiving cavity of the battery casing.

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