Battery case, battery, and battery pack

Abstract

The present application relates to the technical field of batteries, and discloses a battery case, a battery, and a battery pack. The battery case comprises: a main body, and an explosion-proof valve welded to the main body to form a connection section weld seam and a burst section weld seam, wherein the connection section weld seam and the burst section weld seam are connected end to end in the circumferential direction of the explosion-proof valve; and the weld penetration of the connection section weld seam is greater than that of the burst section weld seam, and / or the weld width of the connection section weld seam is greater than that of the burst section weld seam. In the present application, when a battery undergoes runaway, the explosion-proof valve can burst open at a burst section weld seam region, thereby rapidly tearing the entire burst section weld seam, and the explosion-proof valve and the main body are kept connected at the connection section weld seam, allowing the explosion-proof valve to open completely, thereby increasing the area of an air vent of the battery, effectively alleviating battery runaway, and improving the use safety of the battery; in addition, no additional score line needs to be stamped on the explosion-proof valve, thereby avoiding the problem of cracking at the score line when the explosion-proof valve is subjected to stress, and avoiding liquid leakage of the battery.

Description

Battery shell, battery and battery pack

[0001] Cross-reference to related applications

[0002] The present application claims priority to the Chinese patent application No. 202411347982.1, filed on September 26, 2024, and entitled "Battery shell, battery and battery pack", the whole content of which is incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to the technical field of battery, in particular to a battery shell, a battery and a battery pack. BACKGROUND

[0004] A battery generally comprises a battery internal structure and a battery external structure, the battery internal structure mainly comprises a pole group, and the battery external structure mainly comprises a cover plate and a shell. The shell provides a containing space for the pole group, and the cover plate and the shell form a closed space through welding cooperation. In order to ensure the safety of the battery, an explosion-proof valve is usually installed on the cover plate to burst through the explosion-proof valve and release energy when the battery loses control and the internal chemical reaction intensifies to produce gas, thereby relieving the battery loss of control. In the prior art, the explosion-proof valve is realized by stamping a relatively thin residual thickness notch on the explosion-proof valve. However, because the residual thickness of the notch is relatively thin after stamping, the explosion-proof valve has a relatively high risk of failure under stress, and there is a risk of electrolyte leakage caused by cracking at the notch due to stress on the explosion-proof valve during welding of the explosion-proof valve, assembly of the battery cover plate and the shell, and use of the battery. SUMMARY

[0005] Therefore, the present application provides a battery shell, a battery and a battery pack to solve the problem that the notch of the explosion-proof valve is prone to cracking under stress in the prior art.

[0006] In a first aspect, the present application provides a battery shell, comprising: a main body, provided with a mounting hole; an explosion-proof valve, arranged in the mounting hole and welded with the main body to form a connecting segment weld and a bursting segment weld, the connecting segment weld and the bursting segment weld are arranged in a head-to-tail connection along the circumference of the explosion-proof valve; the penetration depth of the connecting segment weld is greater than the penetration depth of the bursting segment weld, and / or the penetration width of the connecting segment weld is greater than the penetration width of the bursting segment weld.

[0007] Beneficial effects: when the battery loses control, the explosion-proof valve can burst in the bursting segment weld area, thereby quickly tearing the entire bursting segment weld, while the connecting segment weld keeps the explosion-proof valve and the main body connected, so that the explosion-proof valve can be completely flipped open, increasing the exhaust port area of the battery, effectively relieving the battery loss of control, and improving the safety of the battery in use; and without additional stamping of a notch on the explosion-proof valve, the problem of cracking at the notch when the explosion-proof valve is stressed is avoided, and battery leakage is avoided.

[0008] In an alternative embodiment, the connecting segment weld corresponds to one side of the explosion-proof valve, the length of the connecting segment weld is Y, the length of the side of the explosion-proof valve where the connecting segment weld is located is L, and 3mm≤Y≤L is satisfied; or the explosion-proof valve is circular, the arc length of the connecting segment weld is Y, the circumference of the explosion-proof valve is C, and 3mm≤Y≤1 / 2xC is satisfied.

[0009] Beneficial effects: By limiting the length of the connecting segment weld, the explosion-proof valve can be quickly torn at the blasting segment weld, and the explosion-proof valve can be completely opened.

[0010] In an alternative embodiment, the fusion width of the blasting segment weld is w1, and 0.5mm≤w1≤0.7mm is satisfied; and / or, the fusion depth of the blasting segment weld is h1, and 0.5mm≤h1≤0.7mm is satisfied.

[0011] Beneficial effects: While ensuring the welding strength of the blasting segment weld and improving the stability of the explosion-proof valve under the pressure in the battery, it is ensured that the explosion-proof valve can be blown open in the blasting segment weld area when the battery is out of control.

[0012] In an alternative embodiment, the fusion width of the connecting segment weld is w2, and 0.8mm≤w2≤1.2mm is satisfied; and / or, the fusion depth of the connecting segment weld is h2, and 0.8mm≤h2≤1.2mm is satisfied.

[0013] Beneficial effects: While ensuring the welding strength of the connecting segment weld, the excessive energy during welding is avoided to reduce the thermal stress, thereby ensuring the welding quality and avoiding problems such as hole blasting and cracking.

[0014] In an alternative embodiment, the thickness of the explosion-proof valve is a, and h2≤a≤2mm is satisfied.

[0015] Beneficial effects: While ensuring that sufficient fusion depth can be achieved during welding, the waste of materials and costs caused by an excessively thick explosion-proof valve is avoided.

[0016] In an alternative embodiment, the outer periphery of the explosion-proof valve and the hole wall of the corresponding mounting hole have a fitting gap e, and 0.05mm≤e≤0.3mm is satisfied.

[0017] Beneficial effects: While ensuring that the explosion-proof valve can be smoothly fitted into the mounting hole, the outer periphery of the explosion-proof valve is more convenient for welding with the main body, and the occupied area of the mounting hole can be minimized to facilitate the arrangement of the remaining components on the main body and ensure the structural strength of the main body.

[0018] In an alternative embodiment, the mounting hole is a stepped hole, the stepped hole comprises coaxially arranged first hole section, second hole section and third hole section, the first step is formed on the outer periphery of the main body corresponding to the first hole section, the second step is formed on the outer periphery of the second hole section with the opening range of the second hole section being smaller than that of the first hole section, the third step is formed on the outer periphery of the third hole section with the opening range of the third hole section being smaller than that of the second hole section, the explosion-proof valve is arranged in the second hole section and located on the third step, and the explosion-proof valve is welded with the second step.

[0019] In an alternative embodiment, the thickness of the first step is b, and b≥0.1mm is satisfied; and / or,

[0020] The width of the second step is c, and c≥w2 / 2+0.1 is satisfied; and / or,

[0021] The thickness difference between the second step and the explosion-proof valve is d, and -0.15mm≤d≤0.15mm is satisfied; and / or,

[0022] The thickness of the third step is f, and f≥h2-a+0.1mm is satisfied; and / or,

[0023] The width of the third step is g, and g≥0.1mm is satisfied.

[0024] Beneficial effects: b≥0.1mm is satisfied to avoid the bulging of the connecting section weld and the blasting section weld from the upper surface of the main body, and to ensure the flatness of the explosion-proof valve patch;

[0025] c≥w2 / 2+0.1 is satisfied to avoid the laser from hitting the upper surface of the main body when the explosion-proof valve is welded with the main body, and to avoid the generation of the spatter to affect the welding quality;

[0026] -0.15mm≤d≤0.15mm is satisfied to avoid the too large thickness difference between the explosion-proof valve and the second step, thereby facilitating the welding of the explosion-proof valve and the second step;

[0027] a+f+0.1≥h2 is satisfied to avoid the molten bead caused by the penetration of the connecting section weld through the lower surface of the main body when the connecting section weld is welded, thereby causing the battery defect;

[0028] g≥0.1mm is satisfied to ensure the stability of the third step supporting the explosion-proof valve.

[0029] In a second aspect, the application further provides a battery comprising the battery shell.

[0030] In a third aspect, the application further provides a battery pack comprising the battery. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the specific embodiments or the prior art, the following will briefly introduce the drawings needed to be used in the description of the specific embodiments or the prior art. Obviously, the drawings described below are some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of these drawings.

[0032] Fig. 1 is an exploded structural schematic view of a battery shell (the main body is a cover plate body) according to an embodiment of the present application;

[0033] Fig. 2 is a structural schematic view of the explosion-proof valve cooperating with the main body in the battery shell shown in Fig. 1;

[0034] Fig. 3 is a top view of a battery shell according to an embodiment of the present application (the explosion-proof valve patch is not shown);

[0035] Fig. 4 is a top view of a battery shell according to an embodiment of the present application;

[0036] Fig. 5 is a sectional view in the direction of A-A in Fig. 4;

[0037] Fig. 6 is a partially enlarged structural schematic view at B in Fig. 5 (welding seam is not shown);

[0038] Fig. 7 is a dimensioned schematic view of Fig. 6;

[0039] Fig. 8 is a schematic view of the penetration and width of the welding seam of the connecting section and the welding seam of the explosion section according to an embodiment of the present application;

[0040] Fig. 9 is a top view of another battery shell according to an embodiment of the present application (the explosion-proof valve patch is not shown).

[0041] Legend of reference signs: 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 welding seam; 4, explosion section welding seam; 5, explosion-proof valve patch. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0043] The embodiments of the present application will be described below in combination with Figs. 1 to 9.

[0044] According to the embodiment of the present application, in one aspect, a battery shell is provided, comprising: a main body 1, provided with a mounting hole 11; an explosion-proof valve 2, arranged in the mounting hole 11 and welded with the main body 1 to form a connecting section weld 3 and an explosion section weld 4, the connecting section weld 3 and the explosion section weld 4 are arranged in a head-to-tail connection along the circumference of the explosion-proof valve 2; the penetration depth of the connecting section weld 3 is greater than the penetration depth of the explosion section weld 4, and / or the penetration width of the connecting section weld 3 is greater than the penetration width of the explosion section weld 4.

[0045] When the battery is out of control, the explosion-proof valve 2 can burst at the explosion section weld 4 area, thereby quickly tearing the entire explosion section weld 4, while 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 completely turned over, increasing the exhaust port area of the battery, effectively relieving the battery out of control, and improving the safety of the battery in use; and without additional notching on the explosion-proof valve 2, the problem of cracking at the notching when the explosion-proof valve 2 is stressed is avoided, and battery liquid leakage is avoided.

[0046] In the present embodiment, please refer to FIGS. 1-3, the explosion-proof valve 2 is a long circular structure (also known as a racetrack shape), that is, it includes two straight edges and two arc-shaped edges, the two straight edges are oppositely spaced, and the two arc-shaped edges are separately arranged on opposite sides of the two straight edges and are respectively connected with the end portions of the two straight edges on the same side. Correspondingly, the entire weld formed by the combination of the connecting section weld 3 and the explosion section weld 4 is also a long circle.

[0047] It should be noted that when the explosion-proof valve 2 is burst by the internal gas pressure of the battery, the explosion-proof valve 2 first bursts at the explosion section weld 4, and then quickly tears the entire explosion section weld 4, and the connecting section weld 3 plays a role of connecting material (similar to the principle of a pop can). Experiments have proved that if there is no connecting section weld 3, the explosion-proof valve 2 has a probability of bursting at the welds of the two straight edges, while the welds of the two arc-shaped edges are still connected, resulting in that the explosion-proof valve 2 cannot be completely turned over, and the exhaust effect is not obvious; and there is also a probability that the explosion-proof valve 2 is ejected to other positions after bursting, causing the battery pack to be overlapped by metal, resulting in further aggravating the short-circuiting of the battery pack.

[0048] It should be noted that the penetration depth of the connecting section weld 3 is greater than the penetration depth of the explosion section weld 4, and / or the penetration width of the connecting section weld 3 is greater than the penetration width of the explosion section weld 4, so that the welding strength of the connecting section weld 3 is greater than the welding strength of the explosion section weld 4.

[0049] It should be noted that the main body 1 can be a cover plate body or a shell. That is, the explosion-proof valve 2 can be installed on the cover plate body or the shell. Specifically, as shown in FIGS. 1-9, in the present embodiment, the main body 1 is a cover plate body.

[0050] In one embodiment, as shown in FIG. 3, the connecting segment weld 3 is arranged corresponding to one side of the explosion-proof valve 2, the length of the connecting segment weld 3 is Y, the length of the side of the explosion-proof valve 2 where the connecting segment weld 3 is located is L, and 3mm≤Y≤L is satisfied. By limiting the length of the connecting segment weld 3, the explosion-proof valve 2 can be quickly torn at the blasting segment weld 4, and it is ensured that the explosion-proof valve 2 can be completely opened.

[0051] Specifically, in the present embodiment, as shown in FIG. 3, the connecting segment weld 3 is arranged corresponding to one straight side of the explosion-proof valve 2, that is, for the long circular weld, the connecting segment weld 3 is arranged on a part of the length (length Y) of the middle position of the straight side, and the remaining part is the blasting segment weld 4.

[0052] It is worth noting that if the length Y of the connecting segment weld 3 is too small, the connecting effect of the connecting segment weld 3 is not obvious, and the explosion-proof valve 2 still has a probability of exploding at the two straight side welds while the two arc side welds are still connected, which causes the explosion-proof valve 2 to be unable to be completely opened. If the length Y of the connecting segment weld 3 is too large, the transition connection between the straight side of the explosion-proof valve 2 where the connecting segment weld 3 is located and the adjacent arc side is too strong, which causes the explosion-proof valve 2 to be more difficult to open.

[0053] As an alternative embodiment, as shown in FIG. 9, the explosion-proof valve 2 is circular, the arc length of the connecting segment weld 3 is Y, the circumference of the explosion-proof valve 2 is C, and 3mm≤Y≤1 / 2×C is satisfied. Specifically, the entire weld formed by the combination of the connecting segment weld 3 and the blasting segment weld 4 is circular, and for the circular weld, the connecting segment weld 3 is arranged on a part of the circular arc (arc length Y), and the remaining circular arc is the blasting segment weld 4.

[0054] In one embodiment, as shown in FIG. 8, the fusion width of the blasting segment weld 4 is w1, and 0.5mm≤w1≤0.7mm is satisfied; the fusion depth of the blasting segment weld 4 is h1, and 0.5mm≤h1≤0.7mm is satisfied. While ensuring the welding strength of the blasting segment 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 be blown open at the blasting segment weld 4 area when the battery is out of control.

[0055] It is worth noting that if w1 and h1 are too small, the welding strength of the explosion-proof valve 2 and the main body 1 is too low, and the explosion-proof valve 2 is prone to separation from the main body 1 when the battery is vibrating and under the internal pressure of the battery, which cannot guarantee the stability and reliability of the explosion-proof valve 2 during use. If w1 and h1 are too large, the welding strength of the explosion-proof valve 2 and the main body 1 is too high, and the explosion-proof valve 2 cannot be blown open at the blasting segment weld 4 when the battery is out of control, which affects the battery exhaust.

[0056] In one embodiment, as shown in FIG. 8, the fusion width of the connecting segment weld 3 is w2, satisfying 0.8mm≤w2≤1.2mm; the fusion depth of the connecting segment weld 3 is h2, satisfying 0.8mm≤h2≤1.2mm. While ensuring the welding strength of the connecting segment weld 3, the excessive energy during welding is avoided to increase the thermal stress, thereby ensuring the welding quality and avoiding problems such as hole blasting and cracking.

[0057] It is worth noting that if w2 and h2 are too small, the welding strength of the connecting segment weld 3 is too low, the connecting effect of the connecting segment weld 3 is not obvious, and the explosion-proof valve 2 still has a chance 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 completely open; if w2 and h2 are too large, the excessive energy during welding will increase the thermal stress, affecting the welding quality, and easily causing problems such as hole blasting and cracking.

[0058] In one embodiment, as shown in FIG. 7, the thickness of the explosion-proof valve 2 is a, satisfying h2≤a≤2mm. While ensuring that sufficient fusion depth can be achieved during welding, the waste of materials and costs caused by the explosion-proof valve 2 being too thick is avoided.

[0059] In one embodiment, as shown in FIG. 7, the outer periphery of the explosion-proof valve 2 and the hole wall of the corresponding mounting hole 11 have a fitting gap e, satisfying 0.05mm≤e≤0.3mm. While ensuring that the explosion-proof valve 2 can be smoothly installed into the mounting hole 11, the outer periphery of the explosion-proof valve 2 is more convenient for welding with the main body 1, and the occupied area of the mounting hole 11 can be minimized to facilitate the arrangement of the remaining components on the main body 1 and ensure the structural strength of the main body 1.

[0060] In one embodiment, as shown in FIGS. 1 and 6, the mounting hole 11 is a stepped hole including coaxially arranged first, second, and third hole segments 111, 112, and 113, the main body 1 forms a first step 12 corresponding to the outer periphery of the first hole segment 111, the second hole segment 112 has a smaller opening range than the first hole segment 111 to form a second step 13 on the outer periphery of the second hole segment 112, the third hole segment 113 has a smaller opening range than the second hole segment 112 to form a third step 14 on the outer periphery of the third hole segment 113, the explosion-proof valve 2 is arranged in the second hole segment 112 and located on the third step 14, and the explosion-proof valve 2 is welded with the second step 13. Therefore, the installation and welding of the explosion-proof valve 2 with the main body 1 are more convenient.

[0061] It is worth noting that, as shown in FIG. 7, the fitting gap between the outer periphery of the explosion-proof valve 2 and the hole wall of the second hole segment 112 is e.

[0062] In one embodiment, as shown in FIG. 7, the thickness of the first step 12 is b, which satisfies b≥0.1mm. Making b≥0.1mm avoids the bulging of the connecting segment weld 3 and the blasting segment weld 4 out of the upper surface of the main body 1, and ensures the flatness of the explosion-proof valve patch 5.

[0063] It is worth mentioning that, in the present embodiment, as shown in FIGS. 1, 2, 4-6, the battery shell further comprises an explosion-proof valve patch 5, which is pasted on the upper surface of the main body 1 through a colloid and is arranged corresponding to the mounting hole 11. Specifically, the explosion-proof valve patch 5 is pasted on the first step 12.

[0064] It needs to be further explained that, referring to FIGS. 4 and 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 can be tested whether the explosion-proof valve 2 leaks during the air tightness test, so as to avoid the occurrence of leakage.

[0065] In one embodiment, as shown in FIG. 7, the width of the second step 13 is c, which satisfies c≥w2 / 2+0.1. Making c≥w2 / 2+0.1 avoids the laser hitting the upper surface of the main body 1 when the explosion-proof valve 2 is welded with the main body 1, and avoids the generation of a blasting point to affect the welding quality.

[0066] In one embodiment, as shown in FIG. 7, the thickness difference between the second step 13 and the explosion-proof valve 2 is d, which satisfies -0.15mm≤d≤0.15mm. Making -0.15mm≤d≤0.15mm avoids the too large thickness difference between the explosion-proof valve 2 and the second step 13, so as to facilitate the welding of the explosion-proof valve 2 and the second step 13, and ensure the welding quality.

[0067] In one embodiment, as shown in FIG. 7, the thickness of the third step 14 is f, which satisfies f≥h2-a+0.1mm. Making f≥h2-a+0.1mm avoids the generation of a molten bead due to the penetration of the melt depth of the connecting segment weld 3 through the lower surface of the main body 1 when welding, which causes the battery to be defective.

[0068] In one embodiment, as shown in FIG. 7, the width of the third step 14 is g, which satisfies g≥0.1mm. Making g≥0.1mm ensures the stability of the third step 14 supporting the explosion-proof valve 2.

[0069] To verify that the cover plate body and the explosion valve 2 of the present embodiment can better complete the explosion opening valve function, the following explosion valve 2 explosion test is carried out on the battery with different explosion segment weld 4, the thickness of the explosion valve 2, and the width of the second step 13. Specifically, the safety valve opening pressure test of 0.6±0.2Mpa is carried out on the iron lithium battery. The test results of the battery of the embodiment and the battery of the comparative example are shown in Table 1. It should be noted that the battery of the embodiment refers to the battery whose explosion segment weld 4, the thickness of the explosion valve 2, and the width of the second step 13 meet the requirements of the present embodiment. Correspondingly, the battery of the comparative example refers to the battery whose explosion segment weld 4, the thickness of the explosion valve 2, or the width of the second step 13 does not meet the requirements of the present embodiment.

[0070] Table 1 Explosion valve explosion test results

[0071] As can be seen from Table 1, in Examples 1 to 6, the value of h1 meets 0.5mm≤h1≤0.7mm, the value of w1 meets 0.5mm≤w1≤0.7mm, and the value of c meets c≥w2 / 2+0.1. Therefore, the batteries of Examples 1 to 6, after the explosion valve 2 is welded with the cover plate body, the appearance is qualified, the explosion valve 2 can be completely opened in the explosion test, and the explosion pressure is in the range of 0.4Mpa to 0.8Mpa, meeting the requirements.

[0072] As can be seen from Table 1, in Comparative Example 1, the value of h1 is 0.48mm, which is not in the range of 0.5mm≤h1≤0.7mm required by the present embodiment and is less than 0.5mm. In the explosion test, the explosion valve 2 of this battery can be opened, but the explosion pressure is lower than 0.4Mpa, which does not meet the requirements.

[0073] As can be seen from Table 1, in Comparative Example 2, the value of w1 is 0.49mm, which is not in the range of 0.5mm≤w1≤0.7mm required by the present embodiment and is less than 0.5mm. In the explosion test, the explosion valve 2 of this battery can be opened, but the explosion pressure is lower than 0.4Mpa, which does not meet the requirements.

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

[0075] As can be seen from Table 1, in the 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 the present embodiment and is greater than 0.7 mm. The battery can open the explosion-proof valve 2 in the explosion test, but the explosion pressure is higher than 0.8 Mpa, which does not meet the requirements.

[0076] As can be seen from Table 1, in the comparative example 5, the value of w2 is 0.83 mm, and the value of c is calculated to be c≥0.515 mm. In the comparative example 5, the value of c is 0.49 mm, which does not meet the requirements. When the explosion-proof valve 2 and the cover plate body are laser welded, the battery appears a burst point, and there is a leakage at the burst point.

[0077] According to the embodiments of the present application, in another aspect, a battery is also provided, which comprises the battery shell described above.

[0078] According to the embodiments of the present application, in still another aspect, a battery pack is also provided, which comprises the battery described above.

[0079] Although the embodiments of the present application are described in conjunction with the accompanying drawings, various modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the present application, and such modifications and changes are intended to fall within the scope of the appended claims.

Claims

1. A battery housing, characterized by include: The main body has mounting holes; An explosion-proof valve is disposed within the mounting hole and welded to the main body to form a connecting section weld and an explosion section weld. The connecting section weld and the explosion 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 that of the explosion section weld, and / or the weld width of the connecting section weld is greater than that of the explosion section weld.

2. The battery case of claim 1, wherein, The connecting section weld is provided corresponding to one side of the explosion-proof valve. The length of the connecting section weld is Y, and 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 weld of the connecting section is Y, and the circumference of the explosion-proof valve is C, satisfying 3mm≤Y≤1 / 2×C.

3. The battery case according to claim 1 or 2, characterized by The weld width of the blasting section is w1, satisfying 0.5mm≤w1≤0.7mm; and / or, the weld depth of the blasting section is h1, satisfying 0.5mm≤h1≤0.7mm.

4. The battery case of claim 3, wherein, The weld width of the connecting section is w2, which satisfies 0.8mm≤w2≤1.2mm; and / or, the weld depth of the connecting section is h2, which satisfies 0.8mm≤h2≤1.2mm.

5. The battery case of claim 4, wherein, The thickness of the explosion-proof valve is a, which satisfies h2≤a≤2mm.

6. The battery case according to claim 1 or 2, characterized by The outer periphery of the explosion-proof valve and the corresponding mounting hole wall have a fitting clearance e, which satisfies 0.05mm≤e≤0.3mm.

7. The battery case of claim 5, wherein, The mounting hole is a stepped hole, which 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 disposed in the second hole segment and located on the third step. The explosion-proof valve is welded to the second step.

8. The battery case of claim 7, wherein, 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, satisfying -0.15mm ≤ d ≤ 0.15mm; and / or, The thickness of the third step is f, satisfying f ≥ h² - a + 0.1 mm; and / or, The width of the third step is g, which satisfies g≥0.1mm.

9. A battery, characterized by The battery casing includes any one of claims 1 to 8.

10. A battery pack, characterized by, Includes the battery as described in claim 9.

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