Battery shell and battery

Abstract

The invention belongs to the technical field of batteries, and discloses a battery shell and a battery, the battery shell comprises a shell assembly, an anti-explosion valve and a protective support, the shell assembly comprises a shell body and at least one cover plate body, the shell body comprises a first wall surface and a second wall surface, and the cover plate body and / or a second wall surface are / is arranged on the first wall surface. A mounting through hole used for mounting an anti-explosion valve is formed in the second wall surface, the protection supports are arranged in the containing cavity and abut against the side, facing the anti-explosion valve, of the pole group, the welding area of each protection support and the first wall surface is S, and the requirement that delta * S is larger than 1.3 F is met. When thermal runaway occurs and an insulating part is heated and melted, the pole group is supported and fixed by using the protective bracket, the pole group is prevented from moving to block the explosion-proof valve, and the welding area S of the protective bracket and the first wall surface is limited, so that enough connection strength between the protective bracket and the first wall surface is ensured, and the reliability of the explosion-proof valve is improved. The protection support is used for resisting the impact of the pole group on the protection support under the pushing of high-temperature and high-pressure gas.

Description

Technical Field

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

[0002] Traditional blade batteries are usually designed with tabs on both sides, and their structure includes a cover plate (with integrated poles, explosion-proof valves, injection holes, etc.), a shell, pole group, electrolyte, etc. After the cover plate and the shell are welded, a closed space with a certain mechanical strength is formed to protect the pole group; the pole group is fixed to the pole base of the cover plate on both sides through laser welding through the tabs on both sides to achieve electrical connection, and the length direction of the battery cell is mainly fixed by the insulating parts under the cover plate pressing on the pole group; the cover plate is integrated with an explosion-proof valve structure, which is mainly used for the directional discharge of internal high-temperature and high-pressure gas when the battery has thermal runaway due to internal short circuit, thereby improving the safety performance of the battery.

[0003] The insulating components inside the battery not only achieve the insulation function, but also abut against the electrode group to fix the electrode group. However, the insulating components are generally made of PP material, and their strength and high temperature resistance are very limited. When the temperature reaches about 150 degrees, the insulating components that fix the electrode group will melt due to the high temperature, thereby losing the effect of fixing the electrode group. However, the temperature at which the battery cell undergoes thermal runaway is usually much higher than the melting point of these insulating components. Therefore, once thermal runaway occurs, the insulating components cannot effectively fix the electrode group, causing the electrode group to move inside the shell, causing the electrode group to block the exhaust channel of the explosion-proof valve, thereby greatly reducing the exhaust effect of the explosion-proof valve when thermal runaway occurs, thereby causing explosions and other adverse problems, and its safety of use is poor. Summary of the invention

[0004] The object of the present invention is to provide a battery casing and a battery, which improve the situation that the pole group blocks the explosion-proof valve and have higher safety in use.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] In one aspect, a battery housing is provided, the battery housing comprising:

[0007] A shell assembly, the shell assembly comprising a shell body and at least one cover body, the shell body comprising a plurality of first walls and at most one second wall, the plurality of first walls are used to enclose a hollow shell structure with double-sided openings, at least one cover body and at most one second wall are arranged at the two-sided openings to form an accommodating cavity for accommodating the pole group, the cover body and / or the second wall are provided with mounting through holes;

[0008] An explosion-proof valve, the explosion-proof valve being arranged at the installation through hole;

[0009] A protective bracket, at least one of which is arranged in the accommodating cavity and connected to the side of the first wall facing the mounting through hole, the protective bracket abuts against the side of the pole group facing the explosion-proof valve, the welding area between each of the protective brackets and the first wall is S, and satisfies, δ×S>1.3F, wherein δ is the shear force coefficient per unit area of ​​the protective bracket along the first direction, and F is the impact force of the high-temperature and high-pressure gas on the pole group.

[0010] Optionally, in a ternary nickel-cobalt-manganese lithium battery system, a height dimension of the protective bracket along the first direction is H1, and satisfies 1.5 mm ≤ H1 < 2 mm.

[0011] Optionally, an inner height dimension of the accommodating cavity along the first direction is H, and satisfies 3.5%≤H1 / H≤5%.

[0012] Optionally, in a lithium iron phosphate battery system, a height dimension of the protective bracket along the first direction is H2, and satisfies 1 mm ≤ H2 < 1.5 mm.

[0013] Optionally, an inner height dimension of the accommodating cavity along the first direction is H, and satisfies 2%≤H2 / H≤3.5%.

[0014] Optionally, the protective bracket includes a connecting portion, which is connected to the first wall surface and has a plurality of welding holes for welding to the first wall surface. The welding area S between each protective bracket and the first wall surface is the total area of ​​the plurality of welding holes.

[0015] Optionally, the protective bracket further includes a limiting portion abutting against the pole group, wherein the limiting portion is disposed between each two adjacent welding through holes and protrudes in a direction away from the connecting portion.

[0016] Optionally, the battery housing further comprises an insulating member, which is disposed on the cover body and the second wall surface on a side facing the electrode group and is provided with avoidance grooves corresponding one to one with the limiting portions.

[0017] Optionally, the cover body includes a closing portion and an inserting portion, the inserting portion is inserted into the opening of the shell body and abuts against a side of the protective bracket away from the pole group, and the closing portion is used to close the opening of the shell body.

[0018] On the other hand, a battery is provided, comprising a pole group and a battery casing as described in any one of the above items, wherein the pole group is arranged in the battery casing.

[0019] Beneficial effects of the present invention:

[0020] The present invention provides a battery casing, which is provided with at least one protective bracket in an accommodating cavity, so that the protective bracket is connected to a side of a first wall facing a mounting through hole and abuts against a pole group. When thermal runaway occurs, even if an insulating component is melted by heat, the protective bracket can still support and fix the pole group, thereby avoiding the problem of the pole group blocking an exhaust passage of an explosion-proof valve due to free movement. Moreover, by limiting the welding area S between each protective bracket and the first wall surface, so that it satisfies δ×S>1.3F, it is ensured that there is sufficient connection strength between the protective bracket and the first wall surface, so as to resist the impact of the pole group on the protective bracket when the pole group is pushed by high-temperature and high-pressure gas, thereby ensuring the fixing strength of the protective bracket to the pole group, avoiding the pole group blocking the exhaust passage of the explosion-proof valve when thermal runaway occurs, and ensuring the exhaust effect of the explosion-proof valve, thereby having higher safety performance.

[0021] The present invention also provides a battery, which, by applying the above-mentioned battery casing, ensures a relatively efficient exhaust efficiency when thermal runaway occurs, so that the pressurized gas during thermal runaway can be released quickly, reducing the risk factor during thermal runaway and improving the safety performance of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural exploded view of the battery housing provided by the present invention;

[0023] Figure 2 It is a schematic diagram of the connection between the housing body and the protective bracket in the battery housing provided by the present invention;

[0024] Figure 3 It is a structural schematic diagram of a protective bracket in a battery housing provided by the present invention.

[0025] In the figure:

[0026] 1. Shell assembly; 11. Shell body; 111. First wall surface; 12. Cover body;

[0027] 2. Explosion-proof valve;

[0028] 3. Protective bracket; 31. Connecting part; 32. Welding through hole; 33. Limiting part;

[0029] 4. Insulating parts; 41. Avoidance groove. DETAILED DESCRIPTION

[0030] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0031] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0033] In the description of this embodiment, the terms "upper", "lower", "right", etc., directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0034] When thermal runaway occurs, the insulating components used to fix the pole group will melt due to the high temperature, making it impossible to effectively fix the pole group. As a result, the pole group will move inside the shell during thermal runaway, thereby blocking the exhaust channel of the explosion-proof valve, greatly reducing the exhaust effect, making it impossible to achieve rapid pressure reduction, and reducing safety of use.

[0035] Therefore, in order to prevent the electrode group from blocking the exhaust passage of the explosion-proof valve due to free movement when thermal runaway occurs, to ensure the exhaust effect and to improve the safety of use, this embodiment provides a battery housing.

[0036] like Figures 1 to 3As shown, the battery shell includes a shell assembly 1, an explosion-proof valve 2 and a protective bracket 3. The shell assembly 1 includes a shell body 11 and at least one cover body 12. The shell body 11 includes multiple first walls 111 and at most one second wall. The multiple first walls 111 are used to enclose a hollow shell structure with double-sided openings. At least one cover body 12 and at most one second wall are arranged at the two side openings to form an accommodating cavity for accommodating the pole group. The cover body 12 and / or the second wall are provided with mounting through holes. The explosion-proof valve 2 is arranged at the mounting through hole. At least one protective bracket 3 is arranged in the accommodating cavity and connected to the side of the first wall 111 facing the mounting through hole. The protective bracket 3 abuts against the side of the pole group facing the explosion-proof valve 2. The welding area between each protective bracket 3 and the first wall 111 is S, and satisfies, δ×S>1.3F, where δ is the shear force coefficient of the protective bracket 3 per unit area along the first direction, and F is the impact force of the pole group subjected to high-temperature and high-pressure gas.

[0037] The battery casing is provided with at least one protective bracket 3 in the accommodating cavity, so that the protective bracket 3 is connected to the side of the first wall 111 facing the mounting through hole and abuts against the pole group. When thermal runaway occurs, even if the insulating component is melted by heat, the protective bracket 3 can still support and fix the pole group, thereby avoiding the problem of the pole group blocking the exhaust passage of the explosion-proof valve 2 due to free movement, and by limiting the welding area S between each protective bracket 3 and the first wall 111 to satisfy δ×S>1.3F, it is ensured that there is sufficient connection strength between the protective bracket 3 and the first wall 111 to resist the impact of the pole group on the protective bracket 3 when the pole group is pushed by high-temperature and high-pressure gas, thereby ensuring the fixing strength of the protective bracket 3 to the pole group, avoiding the pole group from blocking the exhaust passage of the explosion-proof valve 2 when thermal runaway, and ensuring the exhaust effect of the explosion-proof valve 2, thereby having higher safety performance.

[0038] The shear force coefficient δ of the protective bracket 3 per unit area along the first direction is generally 8N / mm 2 Up to 15N / mm 2 During thermal runaway, the pole group is subjected to the impact force F of high-temperature and high-pressure gas, which is usually between 120N and 350N.

[0039] The battery shell can be adapted to different types of batteries, such as blade batteries or square shell batteries. In addition, the battery shell can form blade batteries or square shell batteries of various structures by setting the number of openings of the shell body 11 and the number of cover bodies 12, for example: a blade battery with a shell body 11 with openings on both sides and a double cover body 12, or a blade battery with a shell body 11 with openings on one side and a single cover body 12, or a square shell battery with a shell body 11 with openings on one side and a single cover body 12, etc., and the mounting through holes can be separately arranged on the second wall surface of the shell body 11, or can be separately arranged on the cover body 12, and mounting through holes can also be arranged on the second wall surfaces of the cover body 12 and the shell body 11. In this embodiment, the specific structure of the battery shell is a blade battery shell consisting of a shell body 11 with double-sided openings and a double cover body 12, wherein the mounting through hole is opened on the cover body 12, and the shell body 11 does not have a mounting through hole. The multiple first walls 111 used to form a hollow shell structure are divided into two narrow sides and two wide sides according to the size of the area, wherein each narrow side is connected to a protective bracket 3 on the side facing the mounting through hole, so as to fix the two sides of the pole group, thereby ensuring the fixing strength of the protective bracket 3 to the pole group and preventing the pole group from moving during thermal runaway.

[0040] Alternatively, if Figure 3 As shown, in the ternary nickel-cobalt-manganese lithium battery system, the height dimension of the protective bracket 3 along the first direction is H1, and satisfies 1.5mm≤H1<2mm. By limiting the height dimension H1 of the protective bracket 3 along the first direction to satisfy 1.5mm≤H1<2mm, it is ensured that the protective bracket 3 has sufficient structural strength to avoid deformation of the protective bracket 3 when the pole group impacts the protective bracket 3, which causes the pole group to move.

[0041] In this embodiment, the height dimension H1 of the protective bracket 3 along the first direction can be any value between 1.5 mm and 2 mm or a range between any two values, such as 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, etc.

[0042] Furthermore, the inner height dimension of the accommodating cavity along the first direction is H, and satisfies 3.5%≤H1 / H≤5%. By setting the inner height dimension of the accommodating cavity along the first direction to H, and limiting the ratio of the height dimension H1 of the protective bracket 3 along the first direction to the inner height dimension H of the accommodating cavity along the first direction, so that the ratio of the two satisfies 3.5%≤H1 / H≤5%, it is ensured that the height of the protective bracket 3 is adapted to the pole group after entering the shell, so that the pole group abuts against the protective bracket 3 after entering the shell.

[0043] Alternatively, if Figure 3As shown, in the lithium iron phosphate battery system, the height dimension of the protective bracket 3 along the first direction is H2, and satisfies 1mm≤H2<1.5mm. By limiting the height dimension H2 of the protective bracket 3 along the first direction to satisfy 1mm≤H2<1.5mm, it is ensured that the protective bracket 3 has sufficient structural strength to avoid deformation of the protective bracket 3 when the pole group impacts the protective bracket 3, thereby causing the pole group to move.

[0044] In this embodiment, the height dimension H2 of the protective bracket 3 along the first direction can be any value between 1 mm and 1.5 mm or a range between any two values, such as 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, etc.

[0045] Furthermore, the inner height dimension of the accommodating cavity along the first direction is H, and satisfies 2%≤H2 / H≤3.5%. By setting the inner height dimension of the accommodating cavity along the first direction to H, and limiting the ratio of the height dimension H2 of the protective bracket 3 along the first direction to the inner height dimension H of the accommodating cavity along the first direction, so that the ratio of the two satisfies 2%≤H2 / H≤3.5%, it is ensured that the height of the protective bracket 3 is adapted to the pole group after entering the shell, so that the pole group abuts against the protective bracket 3 after entering the shell.

[0046] In this embodiment, the reason why the ternary nickel-cobalt-manganese lithium battery system and the lithium iron phosphate battery system are limited separately is that in the ternary nickel-cobalt-manganese lithium battery system, the chemical reaction is more violent during thermal runaway, the gas production is large, the gas production rate is high, and the impact force of the pole group on the protective bracket 3 is greater, while in the lithium iron phosphate battery system, the chemical reaction is relatively mild during thermal runaway, the gas production is smaller, the gas production rate is slower, and the impact force of the pole group on the protective bracket 3 is smaller. Therefore, in the two systems, the impact force of the pole group on the protective bracket 3 is different. Therefore, by limiting the height dimension of the protective bracket 3 along the first direction in different systems to different ranges, it is ensured that the protective bracket 3 has sufficient structural strength to avoid dimensional redundancy and waste of materials.

[0047] In this embodiment, in order to verify the influence of the height dimension H1 of the protective bracket 3 along the first direction, the ratio of the height dimension H1 of the protective bracket 3 along the first direction to the inner height dimension H of the accommodating chamber along the first direction, and the welding area S between each protective bracket 3 and the first wall 111 on thermal runaway in the ternary nickel-cobalt-manganese lithium battery system, as shown in Table 1, two groups of embodiments and six groups of comparative examples are provided for verification. In this test, the impact force F of the high-temperature and high-pressure gas on the pole group during thermal runaway is set to 350N, and the shear force coefficient δ per unit area of ​​the protective bracket 3 along the first direction is 9.5N / mm 2 .

[0048] Table 1

[0049]

[0050] In Example 1, the height dimension H1 of the protective bracket 3 along the first direction is set to 1.5 mm, the ratio of the height dimension H1 of the protective bracket 3 along the first direction to the inner height dimension H of the accommodating cavity along the first direction is set to 4%, and the welding area S between each protective bracket 3 and the first wall surface 111 is set to 48 mm. 2 At this time, the thermal runaway safety test result is qualified, the explosion-proof valve 2 exhausts smoothly, and the exhaust effect is not affected.

[0051] In Example 2, the height dimension H1 of the protective bracket 3 along the first direction is set to 1.5 mm, the ratio of the height dimension H1 of the protective bracket 3 along the first direction to the inner height dimension H of the accommodating cavity along the first direction is set to 4%, and the welding area S between each protective bracket 3 and the first wall surface 111 is set to 50 mm. 2 At this time, the thermal runaway safety test result is qualified, the explosion-proof valve 2 exhausts smoothly, and the exhaust effect is not affected.

[0052] It can be seen from Examples 1 to 2 that when the height dimension H1 of the protective bracket 3 along the first direction satisfies the range of 1.5mm≤H1<2mm, the protective bracket 3 has sufficient structural strength and will not deform when the pole group is fixed. When the ratio of the height dimension H1 of the protective bracket 3 along the first direction to the inner height dimension H of the accommodating cavity along the first direction satisfies the range of 3.5%≤H1 / H≤5%, the assembled pole group is just in contact with the protective bracket 3, and there is no gap between the two, so that the pole group will not move. When the welding area S between each protective bracket 3 and the first wall 111 satisfies the range of δ×S>1.3F, the protective bracket 3 and the first wall 111 have sufficient connection strength, and will not fall off under the impact of the pole group during thermal runaway, thereby avoiding the pole group blocking the exhaust passage of the explosion-proof valve 2, and the explosion-proof valve 2 is exhausted smoothly, and the exhaust effect will not be affected, thereby passing the thermal runaway safety test.

[0053] In comparative example 1, the height dimension H1 of the protective bracket 3 along the first direction is set to 1.5 mm, the ratio of the height dimension H1 of the protective bracket 3 along the first direction to the inner height dimension H of the accommodating cavity along the first direction is set to 4%, and the welding area S of each protective bracket 3 and the first wall surface 111 is set to 30 mm. 2 At this time, the thermal runaway safety test result failed, the explosion-proof valve 2 was not exhausting smoothly, and the exhaust effect was weakened.

[0054] In comparative example 2, the height dimension H1 of the protective bracket 3 along the first direction is set to 1.5 mm, the ratio of the height dimension H1 of the protective bracket 3 along the first direction to the inner height dimension H of the accommodating cavity along the first direction is set to 4%, and the welding area S of each protective bracket 3 and the first wall surface 111 is set to 35 mm. 2 At this time, the thermal runaway safety test result failed, the explosion-proof valve 2 was not exhausting smoothly, and the exhaust effect was weakened.

[0055] It can be seen from Comparative Examples 1 to 2 that when the welding area S between each protective bracket 3 and the first wall 111 does not satisfy the range of δ×S>1.3F, the connection strength between the protective bracket 3 and the first wall 111 is insufficient to resist the impact force of the pole group on the protective bracket 3, resulting in the fall-off of the protective bracket 3, causing the pole group to move, thereby blocking the explosion-proof valve 2, so that when thermal runaway occurs, the exhaust is blocked, the explosion-proof valve 2 is not exhausted smoothly, and the exhaust effect is affected to a certain extent, thereby failing the thermal runaway safety test.

[0056] In comparative example 3, the height dimension H1 of the protective bracket 3 along the first direction is set to 1.2 mm, the ratio of the height dimension H1 of the protective bracket 3 along the first direction to the inner height dimension H of the accommodating cavity along the first direction is set to 4%, and the welding area S between each protective bracket 3 and the first wall surface 111 is set to 50 mm. 2 At this time, the thermal runaway safety test result failed, the explosion-proof valve 2 was not exhausting smoothly, and the exhaust effect was weakened.

[0057] In comparative example 4, the height dimension H1 of the protective bracket 3 along the first direction is set to 1 mm, the ratio of the height dimension H1 of the protective bracket 3 along the first direction to the inner height dimension H of the accommodating cavity along the first direction is set to 4%, and the welding area S of each protective bracket 3 and the first wall surface 111 is set to 50 mm. 2 At this time, the thermal runaway safety test result failed, the explosion-proof valve 2 was not exhausting smoothly, and the exhaust effect was weakened.

[0058] It can be seen from Comparative Examples 3 to 4 that when the height dimension H1 of the protective bracket 3 along the first direction does not satisfy the range of 1.5mm≤H1<2mm, the structural strength of the protective bracket 3 itself is unable to resist the impact of the pole group on the protective bracket 3, causing the protective bracket 3 to deform, thereby causing a gap to appear between the protective bracket 3 and the pole group, causing the pole group to move during thermal runaway, thereby blocking the explosion-proof valve 2, so that during thermal runaway, the exhaust is blocked, the explosion-proof valve 2 is not exhausting smoothly, and the exhaust effect is affected to a certain extent, thereby failing the thermal runaway safety test.

[0059] In comparative example 5, the height dimension H1 of the protective bracket 3 along the first direction is set to 1.5 mm, the ratio of the height dimension H1 of the protective bracket 3 along the first direction to the inner height dimension H of the accommodating cavity along the first direction is set to 3.2%, and the welding area S between each protective bracket 3 and the first wall surface 111 is set to 50 mm. 2 At this time, the thermal runaway safety test result failed, the explosion-proof valve 2 was not exhausting smoothly, and the exhaust effect was weakened.

[0060] In comparative example 6, the height dimension H1 of the protective bracket 3 along the first direction is set to 1.5 mm, the ratio of the height dimension H1 of the protective bracket 3 along the first direction to the inner height dimension H of the accommodating cavity along the first direction is set to 3%, and the welding area S of each protective bracket 3 and the first wall surface 111 is set to 50 mm. 2 At this time, the thermal runaway safety test result failed, the explosion-proof valve 2 was not exhausting smoothly, and the exhaust effect was weakened.

[0061] It can be seen from Comparative Examples 5 to 6 that when the ratio of the height dimension H1 of the protective bracket 3 along the first direction to the inner height dimension H of the accommodating chamber along the first direction does not satisfy the range of 3.5%≤H1 / H≤5%, there is a gap between the assembled pole group and the protective bracket 3, so that the pole group cannot be effectively fixed, causing the pole group to move during thermal runaway, thereby blocking the explosion-proof valve 2, so that during thermal runaway, the exhaust is blocked, the explosion-proof valve 2 is not exhausting smoothly, and the exhaust effect is affected to a certain extent, so that the thermal runaway safety test cannot be passed.

[0062] In this embodiment, in order to verify the influence of the height dimension H2 of the protective bracket 3 along the first direction, the ratio of the height dimension H2 of the protective bracket 3 along the first direction to the inner height dimension H of the accommodating chamber along the first direction, and the welding area S between each protective bracket 3 and the first wall 111 on thermal runaway in the lithium iron phosphate battery system, as shown in Table 2, two groups of embodiments and six groups of comparative examples are provided for verification. In this test, the impact force F of the high-temperature and high-pressure gas on the pole group during thermal runaway is set to 250N, and the shear force coefficient δ per unit area of ​​the protective bracket 3 along the first direction is 9.5N / mm 2 .

[0063] Table 2

[0064]

[0065] In Example 3, the height dimension H2 of the protective bracket 3 along the first direction is set to 1 mm, the ratio of the height dimension H2 of the protective bracket 3 along the first direction to the inner height dimension H of the accommodating cavity along the first direction is set to 2%, and the welding area S between each protective bracket 3 and the first wall surface 111 is set to 35 mm. 2At this time, the thermal runaway safety test result is qualified, the explosion-proof valve 2 exhausts smoothly, and the exhaust effect is not affected.

[0066] In Example 4, the height dimension H2 of the protective bracket 3 along the first direction is set to 1 mm, the ratio of the height dimension H2 of the protective bracket 3 along the first direction to the inner height dimension H of the accommodating cavity along the first direction is set to 2%, and the welding area S of each protective bracket 3 and the first wall surface 111 is set to 40 mm. 2 At this time, the thermal runaway safety test result is qualified, the explosion-proof valve 2 exhausts smoothly, and the exhaust effect is not affected.

[0067] It can be seen from Examples 3 to 4 that when the height dimension H2 of the protective bracket 3 along the first direction satisfies the range of 1mm≤H2<1.5mm, the protective bracket 3 has sufficient structural strength and will not deform when the pole group is fixed. When the ratio of the height dimension H2 of the protective bracket 3 along the first direction to the inner height dimension H of the accommodating cavity along the first direction satisfies the range of 2%≤H2 / H≤3.5%, the assembled pole group is just in contact with the protective bracket 3, and there is no gap between the two, so that the pole group will not move. When the welding area S between each protective bracket 3 and the first wall 111 satisfies the range of δ×S>1.3F, the protective bracket 3 and the first wall 111 have sufficient connection strength, and will not fall off under the impact of the pole group during thermal runaway, thereby avoiding the pole group blocking the exhaust passage of the explosion-proof valve 2, and the explosion-proof valve 2 is exhausted smoothly, and the exhaust effect will not be affected, thereby passing the thermal runaway safety test.

[0068] In comparative example 7, the height dimension H2 of the protective bracket 3 along the first direction is set to 1.2 mm, the ratio of the height dimension H2 of the protective bracket 3 along the first direction to the inner height dimension H of the accommodating cavity along the first direction is set to 2.5%, and the welding area S between each protective bracket 3 and the first wall surface 111 is set to 20 mm. 2 At this time, the thermal runaway safety test result failed, the explosion-proof valve 2 was not exhausting smoothly, and the exhaust effect was weakened.

[0069] In comparative example 8, the height dimension H2 of the protective bracket 3 along the first direction is set to 1.2 mm, the ratio of the height dimension H2 of the protective bracket 3 along the first direction to the inner height dimension H of the accommodating cavity along the first direction is set to 2.5%, and the welding area S between each protective bracket 3 and the first wall surface 111 is set to 25 mm. 2 At this time, the thermal runaway safety test result failed, the explosion-proof valve 2 was not exhausting smoothly, and the exhaust effect was weakened.

[0070] It can be seen from Comparative Examples 7 to 8 that when the welding area S between each protective bracket 3 and the first wall 111 does not satisfy the range of δ×S>1.3F, the connection strength between the protective bracket 3 and the first wall 111 is insufficient to resist the impact force of the pole group on the protective bracket 3, resulting in the fall-off of the protective bracket 3, causing the pole group to move, thereby blocking the explosion-proof valve 2, so that when thermal runaway occurs, the exhaust is blocked, the explosion-proof valve 2 is not exhausted smoothly, and the exhaust effect is affected to a certain extent, thereby failing the thermal runaway safety test.

[0071] In comparative example 9, the height dimension H2 of the protective bracket 3 along the first direction is set to 0.8 mm, the ratio of the height dimension H2 of the protective bracket 3 along the first direction to the inner height dimension H of the accommodating cavity along the first direction is set to 2.5%, and the welding area S between each protective bracket 3 and the first wall surface 111 is set to 35 mm. 2 At this time, the thermal runaway safety test result failed, the explosion-proof valve 2 was not exhausting smoothly, and the exhaust effect was weakened.

[0072] In comparative example 10, the height dimension H2 of the protective bracket 3 along the first direction is set to 0.6 mm, the ratio of the height dimension H2 of the protective bracket 3 along the first direction to the inner height dimension H of the accommodating cavity along the first direction is set to 2.5%, and the welding area S between each protective bracket 3 and the first wall surface 111 is set to 35 mm. 2 At this time, the thermal runaway safety test result failed, the explosion-proof valve 2 was not exhausting smoothly, and the exhaust effect was weakened.

[0073] It can be seen from Comparative Examples 9 and 10 that when the height dimension H2 of the protective bracket 3 along the first direction does not satisfy the range of 1mm≤H2<1.5mm, the structural strength of the protective bracket 3 itself is unable to resist the impact of the pole group on the protective bracket 3, causing the protective bracket 3 to deform, thereby causing a gap to appear between the protective bracket 3 and the pole group, causing the pole group to move during thermal runaway, thereby blocking the explosion-proof valve 2, so that during thermal runaway, the exhaust is blocked, the explosion-proof valve 2 is not exhausting smoothly, and the exhaust effect is affected to a certain extent, thereby failing the thermal runaway safety test.

[0074] In comparative example 11, the height dimension H2 of the protective bracket 3 along the first direction is set to 1.2 mm, the ratio of the height dimension H2 of the protective bracket 3 along the first direction to the inner height dimension H of the accommodating cavity along the first direction is set to 1.8%, and the welding area S between each protective bracket 3 and the first wall surface 111 is set to 35 mm. 2 At this time, the thermal runaway safety test result failed, the explosion-proof valve 2 was not exhausting smoothly, and the exhaust effect was weakened.

[0075] In comparative example 12, the height dimension H2 of the protective bracket 3 along the first direction is set to 1.2 mm, the ratio of the height dimension H2 of the protective bracket 3 along the first direction to the inner height dimension H of the accommodating cavity along the first direction is set to 1.6%, and the welding area S between each protective bracket 3 and the first wall surface 111 is set to 35 mm. 2 At this time, the thermal runaway safety test result failed, the explosion-proof valve 2 was not exhausting smoothly, and the exhaust effect was weakened.

[0076] It can be seen from Comparative Examples 11 and 12 that when the ratio of the height dimension H2 of the protective bracket 3 along the first direction to the inner height dimension H of the accommodating chamber along the first direction does not satisfy the range of 2%≤H2 / H≤3.5%, there is a gap between the assembled pole group and the protective bracket 3, so that the pole group cannot be effectively fixed, causing the pole group to move during thermal runaway, thereby blocking the explosion-proof valve 2, so that during thermal runaway, the exhaust is blocked, the explosion-proof valve 2 is not exhausting smoothly, and the exhaust effect is affected to a certain extent, so that the thermal runaway safety test cannot be passed.

[0077] Alternatively, if Figure 3 As shown, the protective bracket 3 includes a connecting portion 31, which is connected to the first wall surface 111 and has a plurality of welding through holes 32 welded to the first wall surface 111. The welding area S between each protective bracket 3 and the first wall surface 111 is the total area of ​​the plurality of welding through holes 32. By providing a plurality of welding through holes 32 on the connecting portion 31 of the protective bracket 3, the welding operation between the protective bracket 3 and the first wall surface 111 of the housing body 11 is facilitated.

[0078] The number and shape of the welding holes 32 provided on the connection portion 31 can be freely set according to the requirements. In the present embodiment, three circular welding holes 32 are provided on the connection portion 31 at intervals, wherein the radius of the welding holes 32 is R, and therefore the welding area S of each protective bracket 3 and the first wall surface 111 is 3×πR. 2 .

[0079] Alternatively, if Figure 3 As shown, the protective bracket 3 also includes a limiting portion 33 that abuts against the pole group, and the limiting portion 33 is provided between each two adjacent welding through holes 32 and protrudes in a direction away from the connecting portion 31. The protective bracket 3 forms the limiting portion 33 by protruding in a direction away from the connecting portion 31, so that the pole group is fixed by the limiting portion 33, and the limiting portion 33 is provided between two adjacent welding through holes 32, so that both sides of the limiting portion 33 have welding points with the first wall surface 111, and the force is better. In this embodiment, since three welding through holes 32 are provided on the connecting portion 31, the protective bracket 3 is formed with two limiting portions 33 for abutting against the pole group.

[0080] Alternatively, if Figure 1 , Figure 3 As shown, the battery housing further includes an insulating member 4, which is disposed on the side of the cover body 12 and the second wall facing the electrode group, and is provided with an escape groove 41 corresponding to the limiting portion 33. By providing the escape groove 41 corresponding to the limiting portion 33 on the insulating member 4, the insulating member 4 is kept to have a relatively large coverage area on the cover body 12 and the second wall, thereby avoiding interference with the protective bracket 3 during assembly.

[0081] In this embodiment, since there are two limiting portions 33 on each protection bracket 3 and one protection bracket 3 is disposed on each narrow side, two avoidance grooves 41 are formed on both sides of the insulating member 4 opposite to the narrow side.

[0082] Optionally, the cover body 12 includes a closing portion and a plug-in portion, the plug-in portion is inserted into the opening of the shell body 11 and abuts against the side of the protective bracket 3 away from the pole group, and the closing portion is used to close the opening of the shell body 11. By providing the plug-in portion on the cover body 12, the contact area between the cover body 12 and the shell body 11 is increased, thereby ensuring the connection strength and sealing after the two are connected.

[0083] In this embodiment, a space is left between the side of the protection bracket 3 facing away from the pole group and the open edge of the shell body 11, so as to avoid interference between the plug-in portion of the cover body 12 and the protection bracket 3 when the cover body 12 is plugged into the shell body 11.

[0084] In this embodiment, a battery is also provided, the battery comprising an electrode group and the above-mentioned battery casing, wherein the electrode group is arranged in the battery casing. By using the above-mentioned battery casing, the battery ensures a relatively high exhaust efficiency when thermal runaway occurs, so that the pressurized gas during thermal runaway can be quickly released, thereby reducing the risk factor during thermal runaway and improving the safety performance of the product.

[0085] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A battery housing, characterized in that: The battery housing comprises: A shell assembly, the shell assembly comprising a shell body and at least one cover body, the shell body comprising a plurality of first walls and at most one second wall, the plurality of first walls are used to enclose a hollow shell structure with double-sided openings, at least one cover body and at most one second wall are arranged at the two-sided openings to form an accommodating cavity for accommodating the pole group, the cover body and / or the second wall are provided with mounting through holes; An explosion-proof valve, the explosion-proof valve being arranged at the installation through hole; A protective bracket, at least one of which is arranged in the accommodating cavity and connected to the side of the first wall facing the mounting through hole, the protective bracket abuts against the side of the pole group facing the explosion-proof valve, the welding area between each of the protective brackets and the first wall is S, and satisfies, δ×S>1.3F, wherein δ is the shear force coefficient per unit area of ​​the protective bracket along the first direction, and F is the impact force of the high-temperature and high-pressure gas on the pole group.

2. The battery housing according to claim 1, characterized in that: In the ternary nickel-cobalt-manganese lithium battery system, the height dimension of the protective bracket along the first direction is H1, and satisfies 1.5mm≤H1<2mm.

3. The battery housing according to claim 2, characterized in that: The inner height dimension of the accommodating cavity along the first direction is H, and satisfies 3.5%≤H1 / H≤5%.

4. The battery housing according to claim 1, characterized in that: In the lithium iron phosphate battery system, the height dimension of the protective bracket along the first direction is H2, and satisfies 1mm≤H2<1.5mm.

5. The battery housing according to claim 4, characterized in that: The inner height dimension of the accommodating cavity along the first direction is H, and satisfies 2%≤H2 / H≤3.5%.

6. The battery housing according to claim 1, characterized in that: The protective bracket includes a connecting portion, which is connected to the first wall surface and has a plurality of welding through holes welded to the first wall surface. The welding area S between each protective bracket and the first wall surface is the total area of ​​the plurality of welding through holes.

7. The battery housing according to claim 6, characterized in that: The protection bracket also includes a limiting portion abutting against the pole group, wherein the limiting portion is arranged between each two adjacent welding through holes and protrudes in a direction away from the connecting portion.

8. The battery casing according to claim 7, characterized in that: The battery housing further comprises an insulating member, which is arranged on the side of the cover body and the second wall facing the electrode group and is provided with avoidance grooves corresponding to the limiting portions one by one.

9. The battery housing according to claim 1, characterized in that: The cover body includes a closing portion and an inserting portion, wherein the inserting portion is inserted into the opening of the shell body and abuts against a side of the protective bracket away from the pole group, and the closing portion is used to close the opening of the shell body.

10. A battery, characterized in that The battery comprises a pole group and a battery casing as claimed in any one of claims 1 to 9, wherein the pole group is arranged in the battery casing.

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