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 a cover plate body, the shell body and / or the cover plate body are / is provided with a mounting through hole for accommodating the anti-explosion valve, the protective support is arranged in an accommodating cavity, and the anti-explosion valve is arranged in the protective support. The shell body is provided with a mounting through hole and comprises a connecting seat and a supporting plate, the connecting seat is connected to the shell body provided with the mounting through hole and / or the cover plate body, the supporting plate is connected to the connecting seat and abuts against the pole group, the projection area of the supporting plate on the shell body or the cover plate body is S1, the cross sectional area of the pole group is S, and S1 / S is larger than or equal to 25% and smaller than 40%. The protection support is used for supporting and fixing the pole group during thermal runaway, the problem that the pole group blocks an exhaust channel of the explosion-proof valve due to free movement is avoided, and the supporting plate and the pole group have enough contact area, so that the fixing effect of the supporting plate on the pole group is guaranteed.

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 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 a cover body, the shell body being provided with at least one opening, the cover body corresponding to the opening of the shell body one by one and closing the opening of the shell body to form an accommodating cavity for accommodating the pole group, the shell body and / or the cover body being provided with a mounting through hole communicating with the accommodating cavity;

[0008] An explosion-proof valve, which is disposed in the mounting through hole and is used to release the pressurized gas inside the accommodating cavity;

[0009] A protective bracket, wherein the protective bracket is arranged in the accommodating cavity and comprises a connecting seat and a support plate, wherein the connecting seat is connected to the shell body provided with the mounting through hole, and / or the cover body, wherein the support plate is connected to the connecting seat and abuts against the pole group, wherein the projection area of ​​the support plate on the shell body or the cover body along the first direction is S1, and the cross-sectional area of ​​the pole group is S, and satisfies 25%≤S1 / S<40%.

[0010] Optionally, the support plate is further provided with a plurality of exhaust holes, and the total effective area of ​​the plurality of exhaust holes for gas circulation is S2, and satisfies 40%≤S2 / S1<60%.

[0011] 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 4.5 mm ≤ H1 < 6 mm.

[0012] Optionally, in a lithium iron phosphate battery system, a height dimension of the protective bracket along the first direction is H2, and satisfies 3mm≤H2<4.5mm.

[0013] Optionally, the protective bracket is mounted on the shell body, and / or the cover body is provided with the mounting through hole, and the mounting through hole is located within the projection of the support plate on the shell body or the cover body.

[0014] Optionally, the battery housing includes a plurality of the protective brackets, and a plurality of the protective brackets are symmetrically distributed at intervals on both sides of the mounting through hole along the second direction.

[0015] Optionally, the exhaust hole is a circular hole, a polygonal hole or an elliptical hole.

[0016] Optionally, there are multiple connecting seats, and the support plate is symmetrically distributed on both sides of the second direction with multiple connecting seats arranged at intervals along the third direction. One end of the multiple connecting seats is connected to the cover plate body and / or the outer shell body, and the support plate is connected to the other end of the multiple connecting seats to form an exhaust passage between the support plate and the outer shell body and / or the cover plate body.

[0017] Optionally, the connecting seat includes a connecting portion and a fixing portion, the connecting portion is vertically connected to the support plate, and the fixing portion is connected to the other end of the connecting portion and is parallel to the support plate.

[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 shell, which is provided with a protective bracket in a receiving cavity, and the protective bracket connected to a cover plate body provided with a mounting through hole and / or the shell body is abutted against a pole group, so that the protective bracket is used to protect the explosion-proof valve. When thermal runaway occurs, even if the 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 the exhaust channel of the explosion-proof valve due to free movement. In addition, the ratio of the projection area S1 of the support plate on the shell body or the cover plate body along the first direction and the cross-sectional area S of the pole group is limited, so that the two satisfy 25%≤S1 / S<40%, thereby avoiding, on the one hand, too small a contact area between the support plate and the pole group, resulting in excessive pressure when the support plate is subjected to the impact of the pole group, and deformation, and on the other hand, avoiding too large a contact area, increasing the structural weight, and failing to meet the lightweight design principle.

[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 three-dimensional isometric view of the assembled cover plate body, explosion-proof valve and protective bracket in the battery housing provided by the present invention;

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

[0024] Figure 3 It is a schematic diagram of the relative positions of the protective bracket and the explosion-proof valve in the battery housing provided by the present invention;

[0025] Figure 4 It is a schematic diagram of the position of the protective brackets in the battery housing provided by the present invention located on both sides of the explosion-proof valve.

[0026] In the figure:

[0027] 1. Cover plate body;

[0028] 2. Explosion-proof valve;

[0029] 3. Protective bracket; 31. Connecting seat; 311. Connecting part; 312. Fixing part; 32. Support plate; 33. Exhaust hole; 34. Exhaust passage. 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 4As shown, the battery shell includes a shell assembly, an explosion-proof valve 2 and a protective bracket 3. The shell assembly includes a shell body and a cover body 1. The shell body is provided with at least one opening. The cover body 1 corresponds to the opening of the shell body one by one and closes the opening of the shell body to form a receiving chamber for receiving the pole group. The shell body and / or the cover body 1 are provided with a mounting through hole connected to the receiving chamber. The explosion-proof valve 2 is provided in the mounting through hole and is used to release the pressure gas inside the receiving chamber. The protective bracket 3 is provided in the receiving chamber and includes a connecting seat 31 and a support plate 32. The connecting seat 31 is connected to the shell body and / or the cover body 1 provided with the mounting through hole. The support plate 32 is connected to the connecting seat 31 and abuts against the pole group. The projection area of ​​the support plate 32 on the shell body or the cover body 1 along the first direction is S1, the cross-sectional area of ​​the pole group is S, and 25%≤S1 / S<40% is satisfied.

[0037] The battery shell is provided with a protective bracket 3 in the accommodating cavity, and the protective bracket 3 connected to the cover plate body 1 with the mounting through hole and / or the shell body is abutted against the pole group, so that the explosion-proof valve 2 is protected by the protective bracket 3. When thermal runaway occurs, even if the insulating component is melted by heat, the protective bracket 3 can also support and fix the pole group, thereby avoiding the problem of the pole group blocking the exhaust channel of the explosion-proof valve 2 due to free movement. In addition, the ratio of the projection area S1 of the support plate 32 on the shell body or the cover plate body 1 along the first direction and the cross-sectional area S of the pole group is limited, so that the two satisfy 25%≤S1 / S<40%, thereby avoiding, on the one hand, the contact area between the support plate 32 and the pole group being too small, resulting in excessive pressure on the support plate 32 when it is subjected to the impact of the pole group, and deformation, and on the other hand, avoiding too large a contact area, increasing the structural weight, and failing to meet the lightweight design principle.

[0038] Among them, 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 be configured to form blade batteries or square shell batteries of various structures by setting the number of openings of the shell body and the number of cover bodies 1, such as: a blade battery with a shell body with double openings and a double cover body 1, or a blade battery with a shell body with a single opening and a single cover body 1, or a square shell battery with a shell body with a single opening and a single cover body 1, etc., and the mounting through hole can be set separately on the shell body, or separately on the cover body 1, or the mounting through hole can be set on both the cover body 1 and the shell body. In this embodiment, the specific structure of the battery shell is a blade battery shell with a shell body with double openings and a double cover body 1, wherein the mounting through hole is opened on the cover body 1, and the shell body is not opened with a mounting through hole, so the protective bracket 3 is arranged on the cover body 1, wherein the protective bracket 3 and the cover body 1 can be separately molded and manufactured and then connected, or the cover body 1 with the protective bracket 3 can be manufactured by an integrated molding process. In this embodiment, the protection bracket 3 and the cover plate body 1 are formed and manufactured separately. After the manufacturing is completed, the protection bracket 3 and the cover plate body 1 are welded.

[0039] Alternatively, if Figure 2 As shown, the support plate 32 is also provided with a plurality of exhaust holes 33, and the total effective area of ​​the plurality of exhaust holes 33 for gas circulation is S2, and satisfies 40%≤S2 / S1<60%. By providing a plurality of exhaust holes 33 on the support plate 32, the pressurized gas can flow freely through the exhaust holes 33 during thermal runaway, so as to avoid the support plate 32 causing obstruction to the pressurized gas and slowing down the flow speed of the pressurized gas when passing through the protective bracket 3, and by limiting the ratio of the total effective area S2 of the plurality of exhaust holes 33 for gas circulation to the projection area S1 of the support plate 32 on the shell body or the cover body 1 along the first direction, so that the ratio of the two satisfies 40%≤S2 / S1<60%, so as to avoid the total effective area S2 of the plurality of exhaust holes 33 for gas circulation on the protective bracket 3 being too small, thereby weakening the exhaust effect, and on the other hand, avoid the plurality of exhaust holes 33 from occupying too large a proportion, thereby reducing the structural strength of the protective bracket 3, causing the protective bracket 3 to deform under the impact of the pole group, so that the protective bracket 3 cannot effectively fix the pole group.

[0040] Specifically, Figure 2 As shown, the exhaust hole 33 is a circular hole, a polygonal hole or an elliptical hole. The shape and number of the exhaust holes 33 can be freely set according to design requirements. In this embodiment, three exhaust holes 33 in the form of elliptical holes are provided on the support plate 32 of each protective bracket 3.

[0041] Alternatively, if Figure 2As 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 4.5mm≤H1<6mm. By limiting the height dimension H1 of the protective bracket 3 along the first direction in the ternary nickel-cobalt-manganese lithium battery system to satisfy 4.5mm≤H1<6mm, on the one hand, it is prevented that the height of the protective bracket 3 along the first direction is too small, resulting in a gap between the protective bracket 3 and the pole group after assembly, so that the pole group still has a small range of movement when thermal runaway occurs, and on the other hand, it is prevented that the height of the protective bracket 3 along the first direction is too large, resulting in the protective bracket 3 occupying more space in the accommodating cavity, so that the volume of the pole group is limited and compressed, resulting in a decrease in energy density.

[0042] In the ternary nickel-cobalt-manganese lithium battery system, the height dimension H1 of the protective bracket 3 along the first direction can be any value between 4.5 mm and 6 mm or a range between any two values, such as 4.5 mm, 5 mm, 5.5 mm, 6 mm, etc.

[0043] Alternatively, if Figure 2 As shown, in the lithium iron phosphate battery system, the height dimension of the protective bracket 3 along the first direction is H2, and satisfies 3mm≤H2<4.5mm. By limiting the height dimension H2 of the protective bracket 3 along the first direction in the lithium iron phosphate battery system to satisfy 3mm≤H2<4.5mm, on the one hand, it is prevented that the height of the protective bracket 3 along the first direction is too small, resulting in a gap between the protective bracket 3 and the pole group after assembly, so that the pole group still has a small range of movement when thermal runaway occurs, and on the other hand, it is prevented that the height of the protective bracket 3 along the first direction is too large, resulting in the protective bracket 3 occupying more space in the accommodating cavity, so that the volume of the pole group is limited and compressed, resulting in a decrease in energy density.

[0044] In the lithium iron phosphate battery system, the height dimension H2 of the protective bracket 3 along the first direction can be any value between 3 mm and 4.5 mm or a range between any two values, such as 3 mm, 3.5 mm, 4 mm, 4.5 mm, etc.

[0045] 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, since the impact force of the pole group on the protective bracket 3 is different, there is a certain difference in the fixing strength of the pole group to the protective bracket 3. By limiting the height dimension of the protective bracket 3 along the first direction to different ranges in different systems, it is ensured that the protective bracket 3 has sufficient fixing strength for the pole group under the current system to avoid size redundancy and waste of materials.

[0046] In this embodiment, in order to verify the influence of the ratio of the projection area S1 of the support plate 32 along the first direction on the outer shell body or the cover plate body 1 to the cross-sectional area S of the electrode group, the ratio of the total effective area S2 of the plurality of exhaust holes 33 for gas circulation to the projection area S1 of the support plate 32 along the first direction on the outer shell body or the cover plate body 1, and the height dimension H1 of the protective bracket 3 along the first direction on thermal runaway in the ternary nickel-cobalt-manganese lithium battery system, as shown in Table 1, two groups of embodiments and eight groups of comparative examples are provided for verification.

[0047] Table 1

[0048]

[0049] In Example 1, the cross-sectional area S of the electrode group is set to 5700 mm 2 , the projection area S1 of the support plate 32 along the first direction on the housing body or the cover body 1 is set to 1500mm 2 , the total effective area S2 of multiple exhaust holes 33 for gas circulation is set to 600mm 2 , the height dimension H1 of the protective bracket 3 along the first direction is set to 4.5 mm. 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.

[0050] In Example 2, the cross-sectional area S of the electrode group is set to 5700 mm 2 , the projection area S1 of the support plate 32 along the first direction on the housing body or the cover body 1 is set to 1500mm 2 The total effective area S2 of the plurality of exhaust holes 33 for gas flow is set to 650 mm 2 , the height dimension H1 of the protective bracket 3 along the first direction is set to 4.5 mm. 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] It can be seen from Examples 1 to 2 that when the ratio of the projection area S1 of the support plate 32 on the outer shell body or the cover body 1 along the first direction to the cross-sectional area S of the electrode group satisfies the range of 25% ≤ S1 / S < 40%, there is a sufficient contact area between the support plate 32 and the electrode group, which not only has a good fixing effect on the electrode group, but also has a small pressure applied to the support plate 32, thereby preventing the support plate 32 from deforming due to excessive pressure. When the ratio of the total effective area S2 of the plurality of exhaust holes 33 for gas circulation to the projection area S1 of the support plate 32 on the outer shell body or the cover body 1 along the first direction satisfies the range of 40% ≤ S2 / S1 < 60%, at this time, the exhaust holes 33 are both The flow rate of the pressurized gas passing through the protective bracket 3 can be guaranteed, and the protective bracket 3 can be guaranteed to have sufficient structural strength to resist the impact of the electrode group on the protective bracket 3, so as to avoid deformation of the protective bracket 3 due to its own weak structural strength. When the height dimension H1 of the protective bracket 3 along the first direction satisfies the range of 4.5mm≤H1<6mm, there is no gap between the assembled protective bracket 3 and the electrode group. For the ternary nickel-cobalt-manganese lithium battery system with more intense chemical reactions, the protective bracket 3 has sufficient fixing strength for the electrode group, so that the electrode group is prevented from blocking the exhaust passage of the explosion-proof valve 2 during thermal runaway, and the explosion-proof valve 2 is exhausted smoothly, and the exhaust effect will not be affected, thereby passing the thermal runaway safety test.

[0052] In Comparative Example 1, the cross-sectional area S of the electrode group is set to 5700 mm 2 , the projection area S1 of the support plate 32 along the first direction on the housing body or the cover body 1 is set to 1300 mm 2 The total effective area S2 of the plurality of exhaust holes 33 for gas flow is set to 530 mm 2 , the height dimension H1 of the protective bracket 3 along the first direction is set to 4.5 mm. At this time, the thermal runaway safety test result is unqualified, the explosion-proof valve 2 is not exhausting smoothly, and the exhaust effect is affected.

[0053] In Comparative Example 2, the cross-sectional area S of the electrode group is set to 5700 mm 2 , the projection area S1 of the support plate 32 along the first direction on the housing body or the cover body 1 is set to 1400 mm 2 The total effective area S2 of the plurality of exhaust holes 33 for gas flow is set to 580 mm 2 , the height dimension H1 of the protective bracket 3 along the first direction is set to 4.5 mm. At this time, the thermal runaway safety test result is unqualified, the explosion-proof valve 2 is not exhausting smoothly, and the exhaust effect is affected.

[0054] It can be seen from Comparative Examples 1 to 2 that when the ratio of the projected area S1 of the support plate 32 on the outer shell body or the cover plate body 1 along the first direction to the cross-sectional area S of the pole group does not satisfy the range of 25%≤S1 / S<40%, at this time, the projected area S1 of the support plate 32 on the outer shell body or the cover plate body 1 along the first direction is too small, resulting in a small contact area between the support plate 32 and the pole group. Therefore, when the thermal runaway pole group impacts the protective bracket 3, the pressure borne by the support plate 32 is too large, causing the support plate 32 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, and 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.

[0055] In Comparative Example 3, the cross-sectional area S of the electrode group is set to 5700 mm 2 , the projection area S1 of the support plate 32 along the first direction on the housing body or the cover body 1 is set to 1500mm 2 The total effective area S2 of the plurality of exhaust holes 33 for gas flow is set to 930 mm 2 , the height dimension H1 of the protective bracket 3 along the first direction is set to 4.5 mm. At this time, the thermal runaway safety test result is unqualified, the explosion-proof valve 2 is not exhausting smoothly, and the exhaust effect is affected.

[0056] In Comparative Example 4, the cross-sectional area S of the electrode group is set to 5700 mm 2 , the projection area S1 of the support plate 32 along the first direction on the housing body or the cover body 1 is set to 1500mm 2 The total effective area S2 of the plurality of exhaust holes 33 for gas flow is set to 950 mm 2 , the height dimension H1 of the protective bracket 3 along the first direction is set to 4.5 mm. At this time, the thermal runaway safety test result is unqualified, the explosion-proof valve 2 is not exhausting smoothly, and the exhaust effect is affected.

[0057] It can be seen from Comparative Examples 3 to 4 that when the ratio of the total effective area S2 of the multiple exhaust holes 33 for gas circulation to the projected area S1 of the support plate 32 on the shell body or the cover body 1 along the first direction is greater than the maximum value of 40%≤S2 / S1<60%, at this time, since the total effective area S2 of the multiple exhaust holes 33 for gas circulation is too large, the structural strength of the protective bracket 3 is greatly reduced, so that when thermal runaway occurs, the protective bracket 3 cannot withstand the impact force of the pole group on the protective bracket 3, and is deformed, thereby causing a gap 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, and 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 it cannot pass the thermal runaway safety test.

[0058] In Comparative Example 5, the cross-sectional area S of the electrode group is set to 5700 mm 2 , the projection area S1 of the support plate 32 along the first direction on the housing body or the cover body 1 is set to 1500mm 2 The total effective area S2 of the multiple exhaust holes 33 for gas circulation is set to 550mm 2 , the height dimension H1 of the protective bracket 3 along the first direction is set to 4.5 mm. At this time, the thermal runaway safety test result is unqualified, the explosion-proof valve 2 is not exhausting smoothly, and the exhaust effect is affected.

[0059] In Comparative Example 6, the cross-sectional area S of the electrode group is set to 5700 mm 2 , the projection area S1 of the support plate 32 along the first direction on the housing body or the cover body 1 is set to 1500mm 2 The total effective area S2 of the multiple exhaust holes 33 for gas circulation is set to 500mm 2 , the height dimension H1 of the protective bracket 3 along the first direction is set to 4.5 mm. At this time, the thermal runaway safety test result is unqualified, the explosion-proof valve 2 is not exhausting smoothly, and the exhaust effect is affected.

[0060] It can be seen from Comparative Examples 5 to 6 that when the ratio of the total effective area S2 of the multiple exhaust holes 33 for gas circulation to the projected area S1 of the support plate 32 on the shell body or the cover body 1 along the first direction is less than the minimum value of 40%≤S2 / S1<60%, at this time, since the total effective area S2 of the multiple exhaust holes 33 for gas circulation is too small, the pressurized gas is blocked by the protective bracket 3 when passing through the protective bracket 3, thereby slowing down the flow rate of the pressurized gas, 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, so that it cannot pass the thermal runaway safety test.

[0061] In Comparative Example 7, the cross-sectional area S of the electrode group is set to 5700 mm 2 , the projection area S1 of the support plate 32 along the first direction on the housing body or the cover body 1 is set to 1500mm 2 , the total effective area S2 of multiple exhaust holes 33 for gas circulation is set to 600mm 2 , the height dimension H1 of the protective bracket 3 along the first direction is set to 4.0 mm. At this time, the thermal runaway safety test result is unqualified, the explosion-proof valve 2 is not exhausting smoothly, and the exhaust effect is affected.

[0062] In Comparative Example 8, the cross-sectional area S of the electrode group is set to 5700 mm 2 , the projection area S1 of the support plate 32 along the first direction on the housing body or the cover body 1 is set to 1600 mm 2, the total effective area S2 of multiple exhaust holes 33 for gas circulation is set to 600mm 2 , the height dimension H1 of the protective bracket 3 along the first direction is set to 3.5 mm. At this time, the thermal runaway safety test result is unqualified, the explosion-proof valve 2 is not exhausting smoothly, and the exhaust effect is affected.

[0063] It can be seen from Comparative Examples 7 to 8 that when the height dimension H1 of the protective bracket 3 along the first direction does not satisfy the range of 4.5mm≤H1<6mm, there is a gap between the assembled protective bracket 3 and the electrode group. For the ternary nickel-cobalt-manganese lithium battery system with relatively intense chemical reactions, the protective bracket 3 has a poor fixing effect on the electrode group, and thus cannot effectively fix the electrode group, causing the electrode group to move during thermal runaway, thereby blocking the explosion-proof valve 2, obstructing exhaust, and causing the explosion-proof valve 2 to exhaust unsmoothly. The exhaust effect is affected to a certain extent, and thus the thermal runaway safety test cannot be passed.

[0064] In this embodiment, in order to verify the influence of the ratio of the projection area S1 of the support plate 32 along the first direction on the outer shell body or the cover plate body 1 to the cross-sectional area S of the electrode group, the ratio of the total effective area S2 of the plurality of exhaust holes 33 for gas circulation to the projection area S1 of the support plate 32 along the first direction on the outer shell body or the cover plate body 1, and the height dimension H2 of the protective bracket 3 along the first direction on thermal runaway in the lithium iron phosphate battery system, as shown in Table 2, two groups of embodiments and eight groups of comparative examples are provided for verification.

[0065] Table 2

[0066]

[0067] In Example 3, the cross-sectional area S of the electrode group is set to 2500 mm 2 , set the projection area S1 of the support plate 32 on the housing body or the cover body 1 along the first direction to 700mm 2 , the total effective area S2 of the plurality of exhaust holes 33 for gas flow is set to 300mm 2 , the height dimension H2 of the protective bracket 3 along the first direction is set to 3.5 mm. 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.

[0068] In Example 4, the cross-sectional area S of the electrode group is set to 2500 mm 2 , set the projection area S1 of the support plate 32 on the housing body or the cover body 1 along the first direction to 700mm 2 The total effective area S2 of the multiple exhaust holes 33 for gas circulation is set to 350mm 2, the height dimension H2 of the protective bracket 3 along the first direction is set to 3.5 mm. 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.

[0069] It can be seen from Examples 3 to 4 that when the ratio of the projection area S1 of the support plate 32 on the outer shell body or the cover body 1 along the first direction to the cross-sectional area S of the electrode group satisfies the range of 25% ≤ S1 / S < 40%, there is a sufficient contact area between the support plate 32 and the electrode group, which not only has a good fixing effect on the electrode group, but also has a small pressure applied to the support plate 32, thereby preventing the support plate 32 from deforming due to excessive pressure. When the ratio of the total effective area S2 of the plurality of exhaust holes 33 for gas circulation to the projection area S1 of the support plate 32 on the outer shell body or the cover body 1 along the first direction satisfies the range of 40% ≤ S2 / S1 < 60%, at this time, the exhaust holes 33 It can not only ensure the flow rate of the pressurized gas passing through the protective bracket 3, but also ensure that the protective bracket 3 has sufficient structural strength to resist the impact of the electrode group on the protective bracket 3, and avoid the deformation of the protective bracket 3 due to its own weak structural strength. When the height dimension H2 of the protective bracket 3 along the first direction satisfies the range of 3mm≤H2<4.5mm, there is no gap between the assembled protective bracket 3 and the electrode group. For the lithium iron phosphate battery system with a relatively mild chemical reaction, the protective bracket 3 has sufficient fixing strength for the electrode group, so that the electrode group is prevented from blocking the exhaust passage of the explosion-proof valve 2 during thermal runaway. The explosion-proof valve 2 exhausts smoothly and the exhaust effect is not affected, thereby passing the thermal runaway safety test.

[0070] In Comparative Example 9, the cross-sectional area S of the electrode group is set to 2500 mm 2 , set the projection area S1 of the support plate 32 on the housing body or the cover body 1 along the first direction to 500mm 2 The total effective area S2 of the plurality of exhaust holes 33 for gas flow is set to 200 mm 2 , the height dimension H2 of the protective bracket 3 along the first direction is set to 3.5 mm. At this time, the thermal runaway safety test result is unqualified, the explosion-proof valve 2 is not exhausting smoothly, and the exhaust effect is affected.

[0071] In Comparative Example 10, the cross-sectional area S of the electrode group is set to 2500 mm 2 , set the projection area S1 of the support plate 32 on the housing body or the cover body 1 along the first direction to 600mm 2 The total effective area S2 of the multiple exhaust holes 33 for gas circulation is set to 250mm 2 , the height dimension H2 of the protective bracket 3 along the first direction is set to 3.5 mm. At this time, the thermal runaway safety test result is unqualified, the explosion-proof valve 2 is not exhausting smoothly, and the exhaust effect is affected.

[0072] It can be seen from Comparative Examples 9 and 10 that when the ratio of the projection area S1 of the support plate 32 on the outer shell body or the cover plate body 1 along the first direction to the cross-sectional area S of the pole group does not satisfy the range of 25%≤S1 / S<40%, at this time, the projection area S1 of the support plate 32 on the outer shell body or the cover plate body 1 along the first direction is too small, resulting in a small contact area between the support plate 32 and the pole group. Therefore, when the thermal runaway pole group impacts the protective bracket 3, the pressure borne by the support plate 32 is too large, causing the support plate 32 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, and 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.

[0073] In Comparative Example 11, the cross-sectional area S of the electrode group is set to 2500 mm 2 , set the projection area S1 of the support plate 32 on the housing body or the cover body 1 along the first direction to 700mm 2 The total effective area S2 of the plurality of exhaust holes 33 for gas flow is set to 440 mm 2 , the height dimension H2 of the protective bracket 3 along the first direction is set to 3.5 mm. At this time, the thermal runaway safety test result is unqualified, the explosion-proof valve 2 is not exhausting smoothly, and the exhaust effect is affected.

[0074] In Comparative Example 12, the cross-sectional area S of the electrode group is set to 2500 mm 2 , set the projection area S1 of the support plate 32 on the shell body or the cover body 1 along the first direction to 700mm 2 The total effective area S2 of the multiple exhaust holes 33 for gas circulation is set to 450mm 2 , the height dimension H2 of the protective bracket 3 along the first direction is set to 3.5 mm. At this time, the thermal runaway safety test result is unqualified, the explosion-proof valve 2 is not exhausting smoothly, and the exhaust effect is affected.

[0075] It can be seen from Comparative Examples 11 to 12 that when the ratio of the total effective area S2 of the multiple exhaust holes 33 for gas circulation to the projected area S1 of the support plate 32 on the shell body or the cover body 1 along the first direction is greater than the maximum value of 40%≤S2 / S1<60%, at this time, since the total effective area S2 of the multiple exhaust holes 33 for gas circulation is too large, the structural strength of the protective bracket 3 is greatly reduced, so that when thermal runaway occurs, the protective bracket 3 cannot withstand the impact force of the pole group on the protective bracket 3, and is deformed, thereby causing a gap 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 when thermal runaway occurs, 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.

[0076] In Comparative Example 13, the cross-sectional area S of the electrode group is set to 2500 mm 2 , set the projection area S1 of the support plate 32 on the shell body or the cover body 1 along the first direction to 700mm 2 The total effective area S2 of the plurality of exhaust holes 33 for gas flow is set to 270 mm 2 , the height dimension H2 of the protective bracket 3 along the first direction is set to 3.5 mm. At this time, the thermal runaway safety test result is unqualified, the explosion-proof valve 2 is not exhausting smoothly, and the exhaust effect is affected.

[0077] In Comparative Example 14, the cross-sectional area S of the electrode group is set to 2500 mm 2 , set the projection area S1 of the support plate 32 on the shell body or the cover body 1 along the first direction to 700mm 2 The total effective area S2 of the plurality of exhaust holes 33 for gas flow is set to 260 mm 2 , the height dimension H2 of the protective bracket 3 along the first direction is set to 3.0 mm. At this time, the thermal runaway safety test result is unqualified, the explosion-proof valve 2 is not exhausting smoothly, and the exhaust effect is affected.

[0078] It can be seen from Comparative Examples 13 and 14 that when the ratio of the total effective area S2 of the multiple exhaust holes 33 for gas circulation to the projected area S1 of the support plate 32 on the shell body or the cover body 1 along the first direction is less than the minimum value of 40%≤S2 / S1<60%, at this time, since the total effective area S2 of the multiple exhaust holes 33 for gas circulation is too small, the pressurized gas is blocked by the protective bracket 3 when passing through the protective bracket 3, thereby slowing down the flow rate of the pressurized gas, 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, so that it cannot pass the thermal runaway safety test.

[0079] In Comparative Example 15, the cross-sectional area S of the electrode group is set to 2500 mm2 , set the projection area S1 of the support plate 32 on the housing body or the cover body 1 along the first direction to 700mm 2 , the total effective area S2 of the plurality of exhaust holes 33 for gas flow is set to 300mm 2 , the height dimension H2 of the protective bracket 3 along the first direction is set to 2.5 mm. At this time, the thermal runaway safety test result is unqualified, the explosion-proof valve 2 is not exhausting smoothly, and the exhaust effect is affected.

[0080] In Comparative Example 16, the cross-sectional area S of the electrode group is set to 2500 mm 2 , set the projection area S1 of the support plate 32 on the housing body or the cover body 1 along the first direction to 700mm 2 , the total effective area S2 of the plurality of exhaust holes 33 for gas flow is set to 300mm 2 , the height dimension H2 of the protective bracket 3 along the first direction is set to 2.0 mm. At this time, the thermal runaway safety test result is unqualified, the explosion-proof valve 2 is not exhausting smoothly, and the exhaust effect is affected.

[0081] It can be seen from Comparative Examples 15 and 16 that when the height dimension H2 of the protective bracket 3 along the first direction does not satisfy the range of 3mm≤H2<4.5mm, there is a gap between the assembled protective bracket 3 and the electrode group. For the lithium iron phosphate battery system with a relatively mild chemical reaction, the protective bracket 3 has a poor fixing effect on the electrode group, and thus cannot effectively fix the electrode group, causing the electrode 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.

[0082] Alternatively, if Figure 3 As shown, the protective bracket 3 is mounted on the outer shell body and / or the cover plate body 1 where a mounting through hole is provided, and the mounting through hole is located within the projection of the support plate 32 on the outer shell body or the cover plate body 1. By arranging the protective bracket 3 on the outer shell body and / or the cover plate body 1 where a mounting through hole is provided, and making the mounting through hole located within the projection of the support plate 32 on the outer shell body or the cover plate body 1, the protective bracket 3 can not only fix the pole group, but also protect the explosion-proof valve 2 facing the inner side of the accommodating cavity, thereby preventing the internal components from damaging the explosion-proof valve 2, thereby affecting the opening pressure of the explosion-proof valve 2.

[0083] Alternatively, if Figure 4As shown, the battery housing includes a plurality of protective brackets 3, and a plurality of protective brackets 3 are symmetrically distributed on both sides of the mounting through hole along the second direction. By symmetrically arranging a plurality of protective brackets 3 on both sides of the mounting through hole along the second direction, the impact force of the pole group on the protective bracket 3 is shared by the plurality of protective brackets 3 when the pole group is in thermal runaway, thereby preventing a single protective bracket 3 from being unable to withstand the impact force of the pole group in thermal runaway, causing deformation of the protective bracket 3, and reducing the fixing effect of the protective bracket 3 on the pole group.

[0084] The number of the protective brackets 3 can be freely set according to actual needs. In this embodiment, the battery housing includes two protective brackets 3, which are respectively arranged on both sides of the mounting through hole along the second direction.

[0085] Alternatively, if Figure 2 As shown, a plurality of connection seats 31 are provided, and a plurality of connection seats 31 spaced along the third direction are symmetrically distributed on both sides of the support plate 32 along the second direction, and one end of the plurality of connection seats 31 is connected to the cover plate body 1, and / or the shell body, and the support plate 32 is connected to the other end of the plurality of connection seats 31, so as to form an exhaust passage 34 between the support plate 32 and the shell body, and / or the cover plate body 1. By connecting the support plate 32 to the other end of the connection seat 31, the pole group is fixed by the support plate 32, and the support plate 32 is elevated, so that an exhaust passage 34 for gas circulation is formed between the support plate 32 and the cover plate body 1 or the shell body, and cooperates with the exhaust hole 33 opened on the support plate 32. When thermal runaway occurs, the pressure gas can pass through the protective bracket 3 in different directions, so as to avoid the protective bracket 3 from hindering the circulation of the pressure gas, slow down the flow speed of the pressure gas when it is discharged, and ensure the efficiency and effect of the exhaust.

[0086] Alternatively, if Figure 2 As shown, the connection seat 31 includes a connection portion 311 and a fixing portion 312. The connection portion 311 is vertically connected to the support plate 32, and the fixing portion 312 is connected to the other end of the connection portion 311 and is parallel to the support plate 32. By providing the fixing portion 312 parallel to the support plate 32, the contact area between the connection seat 31 and the cover plate body 1 or the shell body is increased, which not only provides sufficient welding space for the connection seat 31 during welding, but also ensures that the connection seat 31 and the cover plate body 1 or the shell body have sufficient connection strength after connection.

[0087] 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.

[0088] 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 a cover body, the shell body being provided with at least one opening, the cover body corresponding to the opening of the shell body one by one and closing the opening of the shell body to form an accommodating cavity for accommodating the pole group, the shell body and / or the cover body being provided with a mounting through hole communicating with the accommodating cavity; An explosion-proof valve, which is disposed in the mounting through hole and is used to release the pressurized gas inside the accommodating cavity; A protective bracket, wherein the protective bracket is arranged in the accommodating cavity and comprises a connecting seat and a support plate, wherein the connecting seat is connected to the shell body provided with the mounting through hole, and / or the cover body, wherein the support plate is connected to the connecting seat and abuts against the pole group, wherein the projection area of ​​the support plate on the shell body or the cover body along the first direction is S1, and the cross-sectional area of ​​the pole group is S, and satisfies 25%≤S1 / S<40%.

2. The battery housing according to claim 1, characterized in that: The support plate is also provided with a plurality of exhaust holes, and the total effective area of ​​the plurality of exhaust holes for gas circulation is S2, and satisfies 40%≤S2 / S1<60%.

3. 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 4.5mm≤H1<6mm.

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 3mm≤H2<4.5mm.

5. The battery housing according to claim 1, characterized in that: The protective bracket is mounted on the shell body, and / or the cover body is provided with the mounting through hole, and the mounting through hole is located within the projection of the support plate on the shell body or the cover body.

6. The battery housing according to claim 1, characterized in that: The battery housing comprises a plurality of the protective brackets, and a plurality of the protective brackets are symmetrically distributed at intervals on both sides of the mounting through hole along the second direction.

7. The battery housing according to claim 2, characterized in that: The exhaust hole is a circular hole, a polygonal hole or an elliptical hole.

8. The battery housing according to claim 1, characterized in that: There are multiple connecting seats, and multiple connecting seats are symmetrically distributed on both sides of the support plate along the second direction and are arranged at intervals along the third direction. One end of the multiple connecting seats is connected to the cover plate body and / or the outer shell body, and the support plate is connected to the other end of the multiple connecting seats to form an exhaust passage between the support plate and the outer shell body and / or the cover plate body.

9. The battery housing according to claim 1, characterized in that: The connecting seat comprises a connecting portion and a fixing portion, wherein the connecting portion is vertically connected to the supporting plate, and the fixing portion is connected to the other end of the connecting portion and is parallel to the supporting plate.

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.

Images