Shell structure and battery

Abstract

The invention relates to the technical field of batteries, in particular to a shell structure and a battery, the shell structure comprises a shell and a cover body, the cover body is provided with an anti-explosion valve, the cover body covers one end of the shell in a first direction, and the cover body and the shell define a closed space for accommodating a pole group. A limiting assembly is arranged on the inner wall of the end, close to the cover body, of the shell, protrudes towards the interior of the closed space relative to the inner wall, and is arranged between the cover body and the pole group. The perimeter of a pattern formed by sectioning the closed space in a plane perpendicular to the first direction is defined as C, the sum of the lengths of the ends, facing the pole group, of the limiting assemblies in the circumferential direction of the closed space is defined as A, and A / C is larger than or equal to 45% and smaller than or equal to 65%. According to the shell structure and the battery provided by the invention, the limiting effect of the limiting assembly on the pole group is ensured, and gas in the shell is ensured to be smoothly discharged through the anti-explosion valve under the condition that the battery is overheated.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a shell structure and a battery. Background Art

[0002] Today's batteries usually include a shell, a cover, a lower plastic part and a pole group. The shell and the cover are arranged to form a closed space to accommodate the pole group. The lower plastic part is arranged on the side of the cover facing the pole group. An explosion-proof valve is usually arranged on the cover to discharge the high-pressure gas in the shell. Among them, the battery is mainly pressed on the pole group by the lower plastic to achieve the limitation of the battery shell on the pole group.

[0003] However, the insulating material used to make the lower plastic is generally made of plastic (such as PP material) with a low melting point. When the battery has thermal runaway, as the temperature inside the battery rises sharply, the limiting effect of the lower plastic on the electrode group is easily invalidated due to the melting of the lower plastic, which makes it very easy for the electrode group to be pressed against the inner side of the cover under the impact of the high-pressure airflow inside the shell, thereby causing the electrode group to block the explosion-proof valve, thereby affecting the exhaust smoothness of the explosion-proof valve, reducing the exhaust effect of the explosion-proof valve, and reducing the safety performance of the battery. Summary of the invention

[0004] The purpose of the present application is to provide a shell structure and a battery, so as to solve the existing problem in the prior art that the insulating material of the lower plastic is generally made of plastic material (such as PP material) with a low melting point. When the battery has thermal runaway, as the temperature inside the battery rises sharply, the limiting effect of the lower plastic on the pole group is easily invalidated due to the melting of the lower plastic, which makes the pole group very easy to be pressed against the inner side of the cover under the impact of the high-pressure airflow inside the shell, thereby causing the pole group to block the explosion-proof valve, thereby affecting the exhaust smoothness of the explosion-proof valve, reducing the exhaust effect of the explosion-proof valve, and reducing the technical problem of the safety performance of the battery.

[0005] According to a first aspect of the present application, there is provided a housing structure, comprising a housing and a cover, wherein the cover is provided with an explosion-proof valve, the cover is provided on one end of the housing in a first direction, and the cover and the housing are both arranged to form a closed space for accommodating an electrode group;

[0006] A limit assembly is provided on the inner wall of the shell body close to one end of the cover body, the limit assembly protrudes toward the inside of the closed space relative to the inner wall, and the limit assembly is provided between the cover body and the pole group;

[0007] The perimeter of a figure formed by cutting the closed space with a plane perpendicular to the first direction is defined as C, and the sum of the lengths of the limiting assembly facing one end of the pole group in the circumferential direction of the closed space is defined as A;

[0008] Among them, 45%≤A / C≤65%.

[0009] Preferably, the limiting assembly comprises a plurality of limiting portions, and the plurality of limiting portions are arranged at intervals along the circumferential direction.

[0010] Preferably, end surfaces of the plurality of limiting portions on a side facing the pole group are aligned with each other in the first direction to form a limiting arrangement.

[0011] Preferably, the limiting assembly includes one or more limiting arrays;

[0012] If there are multiple spacer groups, the multiple spacer groups are spaced apart along the first direction.

[0013] Preferably, the total length of the limiting assembly in the circumferential direction facing one end of the pole group is the sum of the dimensions in the circumferential direction of all limiting portions included in the one closest to the pole group among the plurality of limiting arrays.

[0014] Preferably, in the circumferential direction, the limiting portions of the plurality of limiting arrays are staggered with each other.

[0015] Preferably, the limiting assembly is integrally connected to the inner wall of the shell.

[0016] Preferably, an insulating member is further included, which is arranged on a side of the cover body facing the pole group, and when the cover body and the shell are covered with each other, at least a part of the insulating member extends to the closed space.

[0017] Preferably, when the cover body and the housing are covered with each other, at least a portion of the insulating member and the limiting assembly overlap with each other in the first direction.

[0018] According to the second aspect of the present application, a battery is provided, comprising a shell structure as described in any of the above technical solutions, and thus having all the beneficial technical effects of the shell structure, which will not be described in detail herein.

[0019] Compared with the prior art, the beneficial effects of this application are:

[0020] The shell structure provided in the present application can effectively limit the pole group when the limit assembly meets A / C ≥ 45%, so that the pole group can still remain without obvious movement when the battery is overheated and impacted by the internal gas, thereby effectively avoiding the pole group blocking the explosion-proof valve and causing danger. And controlling the A / C of the limit assembly within a range of less than or equal to 65% can effectively avoid the limit assembly being too large in size, blocking the exhaust channel of the battery, and affecting the automatic opening of the explosion-proof valve. In summary, when the limit assembly meets the condition of 45% ≤ A / C ≤ 65%, the shell ensures that the limit assembly is effective in limiting the pole group, and ensures that the gas inside the shell can be smoothly discharged through the explosion-proof valve when the battery is overheated. The safety of the battery is guaranteed.

[0021] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 This is a schematic diagram of the axonometric structure of the shell structure provided in an embodiment of the present application.

[0024] Reference numerals:

[0025] 1-shell; 11-large surface; 12-narrow side surface; 13-limiting part; 2-cover; 21-explosion-proof valve; 221-first pole; 222-second pole; 3-insulating part; 31-avoidance groove; 4-pole group.

[0026] F1-first direction; F2-second direction; F3-third direction. DETAILED DESCRIPTION

[0027] The technical solution of the present application will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0028] The components of the embodiments of the present application generally described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed, but merely represents the selected embodiments of the present application.

[0029] Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of this application.

[0030] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0031] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0032] Refer to the following Figure 1 The shell structure and the battery according to some embodiments of the present application are described.

[0033] See also Figure 1 As shown, an embodiment of the first aspect of the present application provides a shell structure, which includes a shell 1 and a cover body 2, an explosion-proof valve 21 is arranged on the cover body 2, and the cover body 2 is arranged on one end of the shell 1 in the first direction F1, and the cover body 2 and the shell 1 are enclosed to form a closed space for accommodating the pole group 4. A limit assembly is arranged on the inner wall of the shell 1 close to one end of the cover body 2, the limit assembly protrudes toward the inside of the closed space relative to the inner wall, and the limit assembly is arranged between the cover body 2 and the pole group 4. The perimeter of a figure formed by cutting the closed space with a plane perpendicular to the first direction F1 is defined as C, and the sum of the lengths of the limit assembly facing the end of the pole group 4 in the circumferential direction of the closed space is defined as A, wherein 45%≤A / C≤65%.

[0034] Referring to Table 1, it shows that under the structure of the shell 1 of the same size, different sizes of limiting components are selected, and 5 samples are trial-produced for the size of each limiting component, and they are assembled with the electrode group 4 respectively to test the limiting effect of the limiting component on the electrode group 4 in the environment of overheat exhaust after the assembled battery.

[0035]

[0036]

[0037] It can be seen that when the limit assembly meets the condition of A / C ≥ 45%, the limit assembly can effectively limit the pole group 4, so that the pole group 4 can still remain without obvious movement when the battery is overheated and impacted by the internal gas, thereby effectively avoiding the pole group 4 blocking the explosion-proof valve 21 and causing danger. And controlling the A / C of the limit assembly within the range of less than or equal to 65% can effectively avoid the limit assembly being too large in size, blocking the exhaust channel of the battery, and affecting the automatic opening of the explosion-proof valve 21. In summary, when the limit assembly meets the condition of 45% ≤ A / C ≤ 65%, the shell 1 ensures that the limit assembly is effective in limiting the pole group 4, and also ensures that the gas inside the shell 1 can be smoothly discharged through the explosion-proof valve 21 when the battery is overheated. The safety of the battery is guaranteed.

[0038] like Figure 1 As shown, F1 shown in the figure may be an example of the first direction F1. For the convenience of description, two directions intersecting each other on a plane perpendicular to the first direction F1 are defined as a second direction F2 and a third direction F3, respectively. F2 shown in the figure may be an example of the second direction F2, and F3 shown in the figure may be an example of the third direction F3. Taking the example of the shell structure shown in the figure being applicable to a square shell battery as an example, preferably, the first direction F1 may be the length direction of the square shell battery, the second direction F2 may be the width direction of the square shell battery, and the third direction F3 may be the thickness direction of the square shell battery.

[0039] Preferably, if Figure 1 As shown, the above-mentioned limiting assembly may include a plurality of limiting protrusions, and the plurality of limiting protrusions may be arranged at intervals along the above-mentioned circumferential direction. In this way, the gap formed between adjacent limiting portions 13 can facilitate the gas inside the shell 1 to flow to the explosion-proof valve 21.

[0040] Preferably, if Figure 1 As shown, the end faces of the plurality of limiting portions 13 facing the pole group 4 are aligned with each other in the first direction F1 to form a limiting arrangement, so that the limiting arrangement can abut against the pole group 4 in the circumferential direction at the same time, thereby effectively increasing the abutment area between the limiting arrangement and the pole group 4 during the battery overheating exhaust process, thereby preventing the pole group 4 from being damaged during the battery overheating exhaust process.

[0041] Preferably, if Figure 1The figure shows an example in which the above-mentioned limiting assembly includes two limiting groups, and the two limiting groups can be spaced apart along the first direction F1. On the one hand, two limiting groups are set so that once one of the two limiting groups close to the electrode group 4 fails to limit the electrode group 4, the shell 1 can rely on the other of the two limiting groups to limit the electrode group 4, further improving the limiting stability of the limiting assembly on the electrode group 4; on the other hand, the two limiting groups are spaced apart to further ensure the smoothness of the exhaust inside the battery shell 1.

[0042] Furthermore, if Figure 1 As shown, in the circumferential direction, the limiting portions 13 of the plurality of limiting arrays are staggered with each other to further ensure smooth exhaust inside the battery housing 1 .

[0043] Preferably, if Figure 1 As shown, in the same limiting arrangement, the distance between two adjacent limiting portions 13 in the circumferential direction may be greater than the size of the limiting portion 13 in the circumferential direction, so as to further ensure smooth exhaust inside the battery housing 1 .

[0044] However, it is not limited to this, the number of limiting groups included in the above-mentioned limiting component is not limited to the above-mentioned two examples, as long as the limiting property of the limiting component to the pole group 4 can be guaranteed, the number of limiting groups included in the above-mentioned limiting component can also be 1, 3, 4... or more.

[0045] like Figure 1 As shown, taking the example of the above shell structure being applicable to a square-shell battery as an example, the perimeter C of a figure formed by cutting the closed space with a plane perpendicular to the first direction F1 is C=2×(C1+C2).

[0046] Correspondingly, if Figure 1 As shown, the total length of the end of the limiting assembly facing the pole group 4 in the circumferential direction is the sum of the dimensions in the circumferential direction of all the limiting portions 13 included in the one closest to the pole group 4 among the multiple limiting rows.

[0047] Optionally, the size of each limiting portion 13 in the limiting assembly in the circumferential direction is equal. Correspondingly, the total length of the above-mentioned limiting assembly facing the pole group 4 in the circumferential direction is A=n×a.

[0048] Preferably, taking the above-mentioned shell structure as an example for a square shell battery, Figure 1 As shown, the shell 1 may include narrow side surfaces 12 arranged on both sides of the shell 1 in the second direction F2 and large surfaces 11 arranged on both sides of the shell 1 in the third direction F3. The narrow side surfaces 12 and the large surfaces 11 are alternately connected end to end to form the shell 1.

[0049] Preferably, if Figure 1As shown, the size of the limiting portion 13 provided on the narrow side surface 12 in the circumferential direction (ie, Figure 1 a2) is smaller than the size of the limiting portion 13 provided on the large surface 11 in the circumferential direction (ie, Figure 1 a1) is shown so that the limiting portion 13 is better adapted to the above-mentioned shell structure.

[0050] Correspondingly, if Figure 1 As shown, the total length A of the above-mentioned limiting assembly facing one end of the pole group 4 in the circumferential direction is 2×(n1×a1+n2×a2), wherein n1 is the number of the same limiting assembly on the narrow side surface 12, and n2 is the number of the same limiting assembly on the narrow side surface 12.

[0051] Preferably, the above-mentioned limiting assembly can be integrally connected with the inner wall of the shell 1 to further ensure the connection stability between the limiting assembly and the shell 1 , thereby ensuring the limiting stability of the limiting assembly to the pole group 4 .

[0052] In an embodiment, preferably, Figure 1 The shell structure may further include an insulating member 3, which may be disposed on a side of the cover body 2 facing the pole group 4, and when the cover body 2 and the shell 1 are covered with each other, at least a portion of the insulating member 3 extends to the enclosed space. Thus, on the one hand, the insulation between the cover body 2 and the pole group 4 is effectively achieved through the insulating member 3; on the other hand, by at least a portion of the insulating member 3 extending into the enclosed space, when the battery is in normal use, the pole group 4 is limited by the insulating member 3, thereby further ensuring the stability of the pole group 4 in use.

[0053] Preferably, when the cover 2 and the shell 1 cover each other, at least part of the insulating member 3 and the limiting assembly overlap each other in the first direction F1 to save the size of the shell structure in the first direction F1 and thereby improve the space utilization of the shell structure.

[0054] Preferably, if Figure 1 As shown, the side wall of the insulating member 3 may also be provided with an avoidance groove 31. When the cover body 2 and the shell 1 are covered with each other, the limiting portion 13 may be arranged in the avoidance groove 31 to further save the space utilization rate of the shell structure.

[0055] Preferably, if Figure 1 As shown, the avoidance groove 31 is formed open at one end of the insulating member 3 facing the pole group 4 to facilitate the assembly of the insulating member 3 and the limiting portion 13 .

[0056] According to the second aspect of the present application, a battery is provided, comprising a shell structure as described in any of the above technical solutions, and thus having all the beneficial technical effects of the shell structure, which will not be described in detail herein.

[0057] Preferably, if Figure 1 As shown, the battery may include a first pole 221 and a second pole 222. The first pole 221 may be disposed on the cover 2, and the second pole 222 may be disposed on an end of the housing 1 away from the cover 2 in the first direction F1.

[0058] Optionally, not shown in the figure, both the first pole and the second pole may be disposed on the cover.

[0059] Optionally, not shown in the figures, both the first pole and the second pole may be arranged at an end of the shell in the first direction away from the cover body.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A housing structure, characterized in that: It comprises a shell and a cover, wherein the cover is provided with an explosion-proof valve, the cover is provided on one end of the shell in a first direction, and the cover and the shell are both arranged to form a closed space for accommodating an electrode group; A limit assembly is provided on the inner wall of the shell body close to one end of the cover body, the limit assembly protrudes toward the inside of the closed space relative to the inner wall, and the limit assembly is provided between the cover body and the pole group; The perimeter of a figure formed by cutting the closed space with a plane perpendicular to the first direction is defined as C, and the sum of the lengths of the limiting assembly facing one end of the pole group in the circumferential direction of the closed space is defined as A; Among them, 45%≤A / C≤65%.

2. The housing structure according to claim 1, characterized in that: The limiting assembly includes a plurality of limiting portions, and the plurality of limiting portions are arranged at intervals along the circumferential direction.

3. The housing structure according to claim 2, characterized in that: The end surfaces of the plurality of limiting portions on a side facing the pole group are aligned with each other in the first direction to form a limiting row group.

4. The housing structure according to claim 3, characterized in that: The limiting assembly includes one or more limiting rows; If there are multiple spacer groups, the multiple spacer groups are spaced apart along the first direction.

5. The housing structure according to claim 4, characterized in that: The total length of the limiting assembly in the circumferential direction facing one end of the pole group is the sum of the dimensions in the circumferential direction of all limiting portions included in the one of the plurality of limiting arrays closest to the pole group.

6. The housing structure according to claim 4, characterized in that: In the circumferential direction, the limiting portions of the plurality of limiting arrays are staggered with each other.

7. The housing structure according to any one of claims 1 to 6, characterized in that: The limiting assembly is integrally connected to the inner wall of the shell.

8. The housing structure according to any one of claims 1 to 6, characterized in that: It also includes an insulating member, which is arranged on a side of the cover body facing the pole group, and when the cover body and the shell are covered with each other, at least a part of the insulating member extends to the closed space.

9. The housing structure according to claim 8, characterized in that: When the cover body and the housing cover each other, at least a portion of the insulating member and the limiting assembly overlap each other in the first direction.

10. A battery, characterized in that: A housing structure comprising any one of claims 1 to 9.

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