Battery casing, battery and battery pack

Abstract

The present invention relates to the field of battery technology, and discloses a battery shell, a battery and a battery pack, including: a main body; an explosion-proof valve, which is welded with the main body to form a connecting section weld and a bursting section weld, wherein the connecting section weld and the bursting section weld are connected end to end along the circumference of the explosion-proof valve; the melting depth of the connecting section weld is greater than the melting depth of the bursting section weld, and / or the melting width of the connecting section weld is greater than the melting width of the bursting section weld. According to the present invention, when the battery is out of control, the explosion-proof valve can explode in the bursting section weld area, thereby quickly tearing the entire bursting section weld, while keeping the explosion-proof valve and the main body connected at the connecting section weld, so that the explosion-proof valve can be fully opened, increasing the exhaust port area of ​​the battery, effectively alleviating the battery out of control, and improving the safety of battery use; and, there is no need to punch additional notches on the explosion-proof valve, thereby avoiding the problem of cracking at the notch when the explosion-proof valve is subjected to force, and avoiding leakage of the battery.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery casing, a battery and a battery pack. Background Art

[0002] The battery generally includes an internal structure and an external structure. The internal structure mainly includes a pole group, and the external structure mainly includes a cover plate and a shell. The shell provides a storage space for the pole group, and the cover plate and the shell are welded together to form a closed space. In order to ensure the safety of the battery, an explosion-proof valve is usually installed on the cover plate, so that when the internal chemical reaction of the battery is out of control and the gas production intensifies, the explosion-proof valve will be broken after reaching a certain pressure, releasing energy and alleviating the battery out of control. In the prior art, the explosion is achieved by punching out a thin residual thickness notch on the explosion-proof valve. However, due to the thin residual thickness after stamping the notch, the risk of failure of the explosion-proof valve after being stressed is relatively high. During the welding of the explosion-proof valve, the assembly of the battery cover plate and the shell, and the use of the battery, there is a risk that the explosion-proof valve will crack due to stress on the notch, resulting in electrolyte leakage. Summary of the invention

[0003] In view of this, the present invention provides a battery casing, a battery and a battery pack to solve the problem in the prior art that the notch of the explosion-proof valve is easily cracked due to stress.

[0004] In a first aspect, the present invention provides a battery casing, comprising: a main body, provided with a mounting hole; an explosion-proof valve, arranged in the mounting hole and welded to the main body to form a connecting section weld and a bursting section weld, wherein the connecting section weld and the bursting section weld are connected end to end along the circumference of the explosion-proof valve; the fusion depth of the connecting section weld is greater than the fusion depth of the bursting section weld, and / or the fusion width of the connecting section weld is greater than the fusion width of the bursting section weld.

[0005] Beneficial effects: When the battery is out of control, the explosion-proof valve can explode in the explosion section weld area, thereby quickly tearing the entire explosion section weld, and at the same time keeping the explosion-proof valve and the main body connected at the connecting section weld, so that the explosion-proof valve can be fully opened, increasing the exhaust port area of ​​the battery, effectively alleviating battery out of control, and improving the safety of battery use; and, there is no need to punch additional notches on the explosion-proof valve, avoiding the problem of cracking at the notch when the explosion-proof valve is subjected to force, thereby preventing battery leakage.

[0006] In an optional embodiment, the connecting section weld is arranged corresponding to a side of the explosion-proof valve, the length of the connecting section weld is Y, the length of the side of the explosion-proof valve where the connecting section weld is located is L, satisfying 3mm≤Y≤L; or, the explosion-proof valve is circular, the arc length of the connecting section weld is Y, the circumference of the explosion-proof valve is C, satisfying 3mm≤Y≤1 / 2×C.

[0007] Beneficial effect: By limiting the length of the weld of the connecting section, the weld of the explosion-proof valve can be quickly torn in the explosion section, and it is ensured that the explosion-proof valve can be fully opened.

[0008] In an optional embodiment, the molten width of the blasting section weld is w1, satisfying 0.5mm≤w1≤0.7mm; and / or the molten depth of the blasting section weld is h1, satisfying 0.5mm≤h1≤0.7mm.

[0009] Beneficial effect: while ensuring the welding strength of the explosion section weld and improving the stability of the explosion-proof valve under the internal pressure of the battery, it is ensured that the explosion-proof valve can explode in the explosion section weld area when the battery is out of control.

[0010] In an optional embodiment, the weld width of the connecting section weld is w2, satisfying 0.8mm≤w2≤1.2mm; and / or the weld depth of the connecting section weld is h2, satisfying 0.8mm≤h2≤1.2mm.

[0011] Beneficial effect: While ensuring the welding strength of the weld in the connecting section, it avoids excessive energy during welding and increases the influence of thermal stress, thereby ensuring the welding quality and avoiding problems such as hole explosion and cracking.

[0012] In an optional implementation, the thickness of the explosion-proof valve is a, satisfying h2≤a≤2mm.

[0013] Beneficial effect: While ensuring that the welding process can achieve sufficient penetration depth, it avoids the waste of materials and costs caused by the explosion-proof valve being too thick.

[0014] In an optional implementation, the outer periphery of the explosion-proof valve and the corresponding hole wall of the mounting hole have a matching clearance e that satisfies 0.05 mm ≤ e ≤ 0.3 mm.

[0015] Beneficial effects: while ensuring that the explosion-proof valve can be smoothly installed in the installation hole, it is easier to weld the outer edge of the explosion-proof valve to the main body, and can minimize the area occupied by the installation hole, facilitate the arrangement of other components on the main body, and ensure the structural strength of the main body.

[0016] In an optional embodiment, the mounting hole is a stepped hole, and the stepped hole includes a first hole segment, a second hole segment, and a third hole segment arranged coaxially, the main body forms a first step corresponding to the outer periphery of the first hole segment, the opening range of the second hole segment is smaller than the opening range of the first hole segment to form a second step on the outer periphery of the second hole segment, the opening range of the third hole segment is smaller than the opening range of the second hole segment to form a third step on the outer periphery of the third hole segment, the explosion-proof valve is arranged in the second hole segment and is located on the third step, and the explosion-proof valve is welded to the second step.

[0017] In an optional implementation, the thickness of the first step is b, satisfying b≥0.1 mm; and / or,

[0018] The width of the second step is c, satisfying c≥w2 / 2+0.1; and / or,

[0019] The thickness difference between the second step and the explosion-proof valve is d, which satisfies -0.15mm≤d≤0.15mm; and / or,

[0020] The thickness of the third step is f, satisfying f≥h2-a+0.1mm; and / or,

[0021] The width of the third step is g, satisfying g≥0.1 mm.

[0022] Beneficial effect: b≥0.1mm, avoiding the bulging of the welding seams of the connection section and the blasting section protruding from the upper surface of the main body, ensuring the flatness of the explosion-proof valve patch;

[0023] Make c≥w2 / 2+0.1 to prevent the laser from hitting the upper surface of the main body when welding the explosion-proof valve and the main body, so as to avoid explosion points that affect the welding quality;

[0024] Make -0.15mm≤d≤0.15mm to avoid excessive thickness difference between the explosion-proof valve and the second step, thereby facilitating welding of the explosion-proof valve and the second step;

[0025] Make a+f+0.1≥h2 to avoid the weld depth of the connecting section passing through the lower surface of the main body to produce molten beads and cause battery failure;

[0026] Make g ≥ 0.1mm to ensure the stability of the third step in supporting the explosion-proof valve.

[0027] In a second aspect, the present invention further provides a battery, comprising the above-mentioned battery casing.

[0028] In a third aspect, the present invention further provides a battery pack, comprising the above-mentioned battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] 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.

[0030] Figure 1 This is a schematic diagram of the exploded structure of a battery housing (the main body is a cover plate body) according to an embodiment of the present invention;

[0031] Figure 2 for Figure 1 A schematic diagram of the structure of the explosion-proof valve in the battery housing after being matched with the main body;

[0032] Figure 3 A top view of a battery housing according to an embodiment of the present invention (the explosion-proof valve patch is not shown);

[0033] Figure 4 A top view of a battery housing according to an embodiment of the present invention;

[0034] Figure 5 for Figure 4 Sectional view in the AA direction;

[0035] Figure 6 for Figure 5 A schematic diagram of the local enlarged structure at B in the middle (the weld is not shown);

[0036] Figure 7 for Figure 6 Dimensioning diagram of

[0037] Figure 8 A schematic diagram of the penetration depth and width of the connecting section weld / blasting section weld according to an embodiment of the present invention;

[0038] Fig. 9 A top view of another battery housing according to an embodiment of the present invention (the explosion-proof valve patch is not shown).

[0039] Description of reference numerals:

[0040] 1. Main body; 11. Mounting hole; 111. First hole section; 112. Second hole section; 113. Third hole section; 12. First step; 13. Second step; 14. Third step; 2. Explosion-proof valve; 3. Connecting section weld; 4. Explosion section weld; 5. Explosion-proof valve patch. DETAILED DESCRIPTION

[0041] 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.

[0042] Combine the following Figures 1 to 9 , describing an embodiment of the present invention.

[0043] According to an embodiment of the present invention, on the one hand, a battery casing is provided, comprising: a main body 1, which is provided with a mounting hole 11; an explosion-proof valve 2, which is arranged in the mounting hole 11 and welded to the main body 1 to form a connecting section weld 3 and a bursting section weld 4, and the connecting section weld 3 and the bursting section weld 4 are connected end to end along the circumference of the explosion-proof valve 2; the fusion depth of the connecting section weld 3 is greater than the fusion depth of the bursting section weld 4, and / or the fusion width of the connecting section weld 3 is greater than the fusion width of the bursting section weld 4.

[0044] When the battery is out of control, the explosion-proof valve 2 can explode in the area of ​​the explosion section weld 4, thereby quickly tearing the entire explosion section weld 4, and at the same time keeping the explosion-proof valve 2 and the main body 1 connected at the connecting section weld 3, so that the explosion-proof valve 2 can be fully opened, increasing the exhaust port area of ​​the battery, effectively alleviating the battery out of control, and improving the safety of battery use; and, there is no need to punch additional notches on the explosion-proof valve 2, thereby avoiding the problem of cracking at the notch when the explosion-proof valve 2 is subjected to force, and preventing the battery from leaking.

[0045] In this example, see Figures 1 to 3 The explosion-proof valve 2 is an oblong structure (also called a runway shape), that is, it includes two straight sides and two arc-shaped sides, the two straight sides are arranged at intervals, and the two arc-shaped sides are arranged on opposite sides of the two straight sides and are respectively connected to the ends of the two straight sides on the same side. Correspondingly, the entire weld formed by the combination of the connecting section weld 3 and the blasting section weld 4 is also an oblong.

[0046] It should be noted that when the explosion-proof valve 2 is opened by the gas pressure inside the battery, the explosion-proof valve 2 first explodes at the explosion section weld 4, and then quickly tears the entire explosion section weld 4, and the connection section weld 3 plays a role in connecting the materials (similar to the principle of a can). Experiments have shown that if there is no connection section weld 3, the explosion-proof valve 2 has a chance to explode at the two straight edge welds, while the arc-shaped edge welds on both sides are still connected, resulting in the explosion-proof valve 2 being unable to fully open and the exhaust effect being unclear; and there is also a chance that the explosion-proof valve 2 will be ejected to other locations after it explodes, causing the battery pack to be overlapped by metal, further aggravating the short circuit and loss of control of the battery pack.

[0047] It is worth noting that the penetration depth of the connecting section weld 3 is greater than the penetration depth of the blasting section weld 4, and / or the molten width of the connecting section weld 3 is greater than the molten width of the blasting section weld 4, thereby making the welding strength of the connecting section weld 3 greater than the welding strength of the blasting section weld 4.

[0048] It should be noted that the main body 1 can be a cover body or a shell. That is, the explosion-proof valve 2 can be installed on the cover body or on the shell. Figures 1 to 9 As shown, in this embodiment, the main body 1 is a cover plate body.

[0049] In one embodiment, Figure 3As shown, the connection section weld 3 is arranged corresponding to a side of the explosion-proof valve 2, the length of the connection section weld 3 is Y, and the length of the side of the explosion-proof valve 2 where the connection section weld 3 is located is L, satisfying 3mm≤Y≤L. By limiting the length of the connection section weld 3, it is convenient for the explosion-proof valve 2 to be quickly torn at the bursting section weld 4, and it is ensured that the explosion-proof valve 2 can be fully opened.

[0050] Specifically, in this embodiment, Figure 3 As shown, the connecting section weld 3 is arranged corresponding to a straight side of the explosion-proof valve 2, that is, for the oblong weld, there is a connecting section weld 3 on a partial length (length Y) in the middle of a straight side, and the remaining part is the explosion section weld 4.

[0051] It is worth noting that if the length Y of the connecting section weld 3 is too small, the connecting material effect of the connecting section weld 3 is not obvious, which will still cause the explosion-proof valve 2 to explode at the two straight edge welds, while the two arc-shaped edge welds are still connected, resulting in the explosion-proof valve 2 being unable to be fully opened; if the length Y of the connecting section weld 3 is too large, the bonding force at the transition connection between the straight edge of the explosion-proof valve 2 where the connecting section weld 3 is located and the adjacent arc-shaped edge will be too strong, resulting in the explosion-proof valve 2 being more difficult to open.

[0052] As an alternative embodiment, Fig. 9 As shown, the explosion-proof valve 2 is circular, the arc length of the connecting section weld 3 is Y, and the circumference of the explosion-proof valve 2 is C, which satisfies 3mm≤Y≤1 / 2×C. Specifically, the entire weld formed by the connecting section weld 3 and the bursting section weld 4 is circular. For a circular weld, the connecting section weld 3 is provided on part of the arc (arc length is Y), and the bursting section weld 4 is provided on the rest of the arc.

[0053] In one embodiment, Figure 8 As shown, the molten width of the blasting section weld 4 is w1, which satisfies 0.5mm≤w1≤0.7mm; the molten depth of the blasting section weld 4 is h1, which satisfies 0.5mm≤h1≤0.7mm. While ensuring the welding strength of the blasting section weld 4 and improving the stability of the explosion-proof valve 2 under the internal pressure of the battery, it is ensured that the explosion-proof valve 2 can explode in the blasting section weld 4 area when the battery is out of control.

[0054] It is worth noting that if w1 and h1 are too small, the welding strength between the explosion-proof valve 2 and the main body 1 is too low. When the battery vibrates and under the internal pressure of the battery, the explosion-proof valve 2 is easy to separate from the main body 1, and the stability and reliability of the explosion-proof valve 2 during use cannot be guaranteed; if w1 and h1 are too large, the welding strength between the explosion-proof valve 2 and the main body 1 is too high. When the battery is out of control, it cannot explode at the explosion section weld 4, affecting the battery exhaust.

[0055] In one embodiment, Figure 8As shown, the weld width of the connecting section weld 3 is w2, which satisfies 0.8mm≤w2≤1.2mm; the weld depth of the connecting section weld 3 is h2, which satisfies 0.8mm≤h2≤1.2mm. While ensuring the welding strength of the connecting section weld 3, it is avoided that the energy during welding is too high and the influence of thermal stress is increased, thereby ensuring the welding quality and avoiding problems such as explosion holes and cracks.

[0056] It is worth noting that if w2 and h2 are too small, the welding strength of the connecting section weld 3 is too low, and the connecting material effect of the connecting section weld 3 is not obvious, which will still cause the explosion-proof valve 2 to explode at the two straight edge welds with a probability, while the two arc edge welds are still connected, resulting in the explosion-proof valve 2 being unable to be fully opened; if w2 and h2 are too large, excessive energy during welding will increase the influence of thermal stress, affect the welding quality, and easily cause problems such as blowout and cracking.

[0057] In one embodiment, Figure 7 As shown, the thickness of the explosion-proof valve 2 is a, satisfying h2≤a≤2mm. While ensuring that the welding process can achieve sufficient penetration depth, the explosion-proof valve 2 is prevented from being too thick, resulting in waste of materials and costs.

[0058] In one embodiment, Figure 7 As shown, the outer periphery of the explosion-proof valve 2 and the corresponding hole wall of the mounting hole 11 have a matching clearance e, which satisfies 0.05mm≤e≤0.3mm. While ensuring that the explosion-proof valve 2 can be smoothly installed in the mounting hole 11, it is more convenient to weld the outer periphery of the explosion-proof valve 2 with the main body 1, and the area occupied by the mounting hole 11 can be minimized, which is convenient for the arrangement of other components on the main body 1 and ensures the structural strength of the main body 1.

[0059] In one embodiment, Figure 1 and Figure 6 As shown, the mounting hole 11 is a stepped hole, and the stepped hole includes a first hole section 111, a second hole section 112, and a third hole section 113 which are coaxially arranged. The main body 1 forms a first step 12 corresponding to the outer periphery of the first hole section 111, and the opening range of the second hole section 112 is smaller than the opening range of the first hole section 111 to form a second step 13 on the outer periphery of the second hole section 112. The opening range of the third hole section 113 is smaller than the opening range of the second hole section 112 to form a third step 14 on the outer periphery of the third hole section 113. The explosion-proof valve 2 is arranged in the second hole section 112 and is located on the third step 14. The explosion-proof valve 2 is welded to the second step 13. Therefore, it is more convenient to install and weld the explosion-proof valve 2 to the main body 1.

[0060] It is worth mentioning that please refer to Figure 7 The matching clearance between the outer periphery of the explosion-proof valve 2 and the hole wall of the second hole section 112 is e.

[0061] In one embodiment, Figure 7 As shown, the thickness of the first step 12 is b, which satisfies b≥0.1 mm. When b≥0.1 mm, the connection section weld 3 and the blasting section weld 4 are prevented from bulging out of the upper surface of the main body 1, and the flatness of the explosion-proof valve patch 5 is ensured.

[0062] It is worth noting that, in this embodiment, Figure 1 , Figure 2 , Figures 4 to 6 As shown, the battery housing further includes an explosion-proof valve patch 5 , which is adhered to the upper surface of the main body 1 through a colloid and arranged corresponding to the mounting hole 11 . Specifically, the explosion-proof valve patch 5 is adhered to the first step 12 .

[0063] For further explanation, please refer to Figure 4 and Figure 6 One side of the explosion-proof valve patch 5 has a notch so that the explosion-proof valve patch 5 does not completely cover the mounting hole 11. Therefore, it is possible to test whether the explosion-proof valve 2 is leaking during the air tightness test to avoid leakage.

[0064] In one embodiment, Figure 7 As shown, the width of the second step 13 is c, which satisfies c≥w2 / 2+0.1. When c≥w2 / 2+0.1, the laser is prevented from hitting the upper surface of the main body 1 when the explosion-proof valve 2 is welded to the main body 1, thereby preventing explosion points from affecting the welding quality.

[0065] In one embodiment, Figure 7 As shown, the thickness difference between the second step 13 and the explosion-proof valve 2 is d, which satisfies -0.15mm≤d≤0.15mm. By making -0.15mm≤d≤0.15mm, it is avoided that the explosion-proof valve 2 and the second step 13 have too large a thickness difference, thereby facilitating the welding of the explosion-proof valve 2 and the second step 13 and ensuring the welding quality.

[0066] In one embodiment, Figure 7 As shown, the thickness of the third step 14 is f, which satisfies f≥h2-a+0.1mm. When f≥h2-a+0.1mm, it is prevented that the weld 3 of the connecting section penetrates the lower surface of the main body 1 to generate a molten bead and cause battery failure.

[0067] In one embodiment, Figure 7 As shown, the width of the third step 14 is g, which satisfies g≥0.1 mm. When g≥0.1 mm, the stability of the third step 14 in supporting the explosion-proof valve 2 is ensured.

[0068] In order to verify that the matching structure of the cover plate body and the explosion-proof valve 2 of this embodiment can better complete the explosion-starting and valve-opening function, the explosion-proof valve 2 explosion test is carried out on batteries with different fusion depths and fusion widths of the explosion section weld 4, the thickness of the explosion-proof valve 2, and the width of the second step 13. Specifically, a safety valve opening pressure test of 0.6±0.2Mpa of an iron-lithium battery is adopted. The test results of the embodiment battery and the comparative example battery are shown in Table 1. It should be noted that the embodiment battery refers to a battery whose fusion depth and fusion width of the explosion section weld 4, the thickness of the explosion-proof valve 2, and the width of the second step 13 meet the requirements of this embodiment. Correspondingly, the comparative example battery refers to a battery whose fusion depth, or fusion width, or the thickness of the explosion-proof valve 2, or the width of the second step 13 of the explosion section weld 4 do not meet the requirements of this embodiment.

[0069] Table 1 Explosion test results of explosion-proof valve 2

[0070]

[0071] It can be seen from Table 1 that in Examples 1 to 6, the value of h1 satisfies 0.5mm≤h1≤0.7mm, the value of w1 satisfies 0.5mm≤w1≤0.7mm, and the value of c satisfies c≥w2 / 2+0.1. Therefore, in the batteries of Examples 1 to 6, the appearance of the explosion-proof valve 2 after welding with the cover plate body is qualified, the explosion-proof valve 2 can be fully opened in the explosion test, and the detonation pressure is within the range of 0.4Mpa to 0.8Mpa, which meets the requirements.

[0072] It can be seen from Table 1 that in Comparative Example 1, the value of h1 is 0.48 mm, which is not within the range of 0.5 mm ≤ h1 ≤ 0.7 mm required by this embodiment and is less than 0.5 mm. The explosion-proof valve 2 of the battery can be opened in the explosion test, but the detonation pressure is lower than 0.4 MPa, which does not meet the requirements.

[0073] It can be seen from Table 1 that in Comparative Example 2, the value of w1 is 0.49 mm, which is not within the range of 0.5 mm ≤ w1 ≤ 0.7 mm required by this embodiment and is less than 0.5 mm. The explosion-proof valve 2 of the battery can be opened in the explosion test, but the detonation pressure is lower than 0.4 MPa, which does not meet the requirements.

[0074] It can be seen from Table 1 that in Comparative Example 3, the value of h1 is 0.71 mm, which is not within the range of 0.5 mm ≤ h1 ≤ 0.7 mm required by this embodiment and is greater than 0.7 mm. The explosion-proof valve 2 of the battery can be opened in the explosion test, but the detonation pressure is higher than 0.8 MPa, which does not meet the requirements.

[0075] It can be seen from Table 1 that in Comparative Example 4, the value of w1 is 0.72 mm, which is not within the range of 0.5 mm ≤ w1 ≤ 0.7 mm required by this embodiment and is greater than 0.7 mm. The explosion-proof valve 2 of the battery can be opened in the explosion test, but the detonation pressure is higher than 0.8 MPa, which does not meet the requirements.

[0076] It can be seen from Table 1 that in Comparative Example 5, the value of w2 is 0.83 mm. After calculation, the value range of c is c ≥ 0.515 mm. In Comparative Example 5, the value of c is 0.49 mm, which does not meet the requirements. The battery has an explosion point when the explosion-proof valve 2 is laser welded to the cover body, and there is leakage at the explosion point.

[0077] According to an embodiment of the present invention, on the other hand, a battery is provided, comprising the above-mentioned battery casing.

[0078] According to an embodiment of the present invention, in yet another aspect, a battery pack is provided, comprising the above-mentioned battery.

[0079] 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 housing, comprising: The main body is provided with a mounting hole; The explosion-proof valve is arranged in the mounting hole and welded to the main body to form a connecting section weld and a bursting section weld, wherein the connecting section weld and the bursting section weld are connected end to end along the circumference of the explosion-proof valve; the penetration depth of the connecting section weld is greater than the penetration depth of the bursting section weld, and / or the fusion width of the connecting section weld is greater than the fusion width of the bursting section weld; characterized in that: The connecting section weld is arranged corresponding to a side of the explosion-proof valve, the length of the connecting section weld is Y, the rest is the bursting section weld, the length of the side of the explosion-proof valve where the connecting section weld is located is L, and 3mm≤Y≤L is satisfied; or, The explosion-proof valve is circular, the arc length of the connecting section weld is Y, the remaining arc is the bursting section weld, and the circumference of the explosion-proof valve is C, satisfying 3mm≤Y≤1 / 2×C.

2. The battery housing according to claim 1, characterized in that: The molten width of the blasting section weld is w1, satisfying 0.5mm≤w1≤0.7mm; and / or the molten depth of the blasting section weld is h1, satisfying 0.5mm≤h1≤0.7mm.

3. The battery housing according to claim 2, characterized in that: The weld width of the connecting section weld is w2, satisfying 0.8mm≤w2≤1.2mm; and / or the weld depth of the connecting section weld is h2, satisfying 0.8mm≤h2≤1.2mm.

4. The battery housing according to claim 3, characterized in that: The thickness of the explosion-proof valve is a, satisfying h2≤a≤2mm.

5. The battery housing according to claim 1, characterized in that: The outer periphery of the explosion-proof valve and the corresponding hole wall of the mounting hole have a matching clearance e, satisfying 0.05mm≤e≤0.3mm.

6. The battery housing according to claim 4, characterized in that: The mounting hole is a stepped hole, and the stepped hole includes a first hole segment, a second hole segment, and a third hole segment that are coaxially arranged. The main body forms a first step corresponding to the outer periphery of the first hole segment, the opening range of the second hole segment is smaller than the opening range of the first hole segment to form a second step on the outer periphery of the second hole segment, the opening range of the third hole segment is smaller than the opening range of the second hole segment to form a third step on the outer periphery of the third hole segment, the explosion-proof valve is arranged in the second hole segment and is located on the third step, and the explosion-proof valve is welded to the second step.

7. The battery housing according to claim 6, characterized in that: The thickness of the first step is b, satisfying b≥0.1 mm; and / or, The width of the second step is c, satisfying c≥w2 / 2+0.1; and / or, The thickness difference between the second step and the explosion-proof valve is d, which satisfies -0.15mm≤d≤0.15mm; and / or, The thickness of the third step is f, satisfying f≥h2-a+0.1mm; and / or, The width of the third step is g, satisfying g≥0.1 mm.

8. A battery, characterized in that: A battery casing comprising the battery casing according to any one of claims 1 to 7.

9. A battery pack, characterized in that: Comprising the battery as claimed in claim 8.

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