Battery cell and battery module

Abstract

The invention relates to the technical field of batteries, in particular to a battery cell and a battery module, the battery cell comprises a shell, a first cover plate and a pole group, the shell is enclosed to form a space extending along a first direction, the first cover plate covers one end of the shell in the first direction, an anti-explosion valve is arranged on the first cover plate, and the pole group is arranged on the shell. Limiting stop blocks are arranged on the inner walls of the two sides of the shell in the second direction, the pole group is arranged in the shell, the limiting stop blocks are arranged between the first cover plate and the pole group, and the second direction intersects with the first direction. And the size of the shell in the second direction is defined as A, the wall thickness of the shell is defined as t, the size of the pole group in the second direction is defined as B, and the size of the limiting stop block in the second direction is defined as C. According to the battery cell and the battery module provided by the invention, the pole group is effectively limited by the limiting stop block, so that the stability of the battery cell is improved, and the service life of the battery cell is prolonged. The anti-explosion valve on the first cover plate is prevented from being blocked by the movement of the pole group in the first direction, and the safety of the battery cell is improved.

Description

Technical Field

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

[0002] Today's battery cells usually include a shell, a cover plate, a lower plastic part and a pole group. The shell and the cover plate are enclosed to form a closed space for accommodating the pole group. The lower plastic part is arranged on the side of the cover plate facing the pole group. An explosion-proof valve is usually arranged on the cover plate to discharge the high-pressure gas in the shell. Among them, the battery cell is mainly pressed on the pole group by the lower plastic to achieve the limit position of the 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 cell has thermal runaway, as the temperature inside the battery cell 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 it very easy for the pole group to be pressed against the inner side of the cover plate 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 safety performance of the battery cell. Summary of the invention

[0004] The purpose of the present application is to provide a battery cell and a battery module, 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 cell has thermal runaway, as the temperature inside the battery cell rises sharply, the limiting effect of the lower plastic part on the pole group is very likely to fail due to the melting of the lower plastic part, which makes the pole group very likely to be pressed against the inner side of the cover plate 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 cell.

[0005] According to a first aspect of the present application, a battery cell is provided, comprising a shell, a first cover plate and a pole group, wherein the shell is enclosed to form a space extending along a first direction, the first cover plate is covered at one end of the shell in the first direction, an explosion-proof valve is arranged on the first cover plate, and limit stops are arranged on inner walls on both sides of the shell in a second direction, the pole group is arranged in the shell, and the limit stops are arranged between the first cover plate and the pole group, and the second direction intersects with the first direction;

[0006] Define the size of the shell in the second direction as A, the wall thickness of the shell as t, the size of the pole group in the second direction as B, and the size of the limit stopper in the second direction as C, wherein,

[0007] Preferably, 1.0 mm ≤ A-2t-B ≤ 1.6 mm.

[0008] Preferably, a dimension of the shell in the second direction is 80 mm to 190 mm.

[0009] Preferably, the wall thickness of the shell is 0.3 mm to 1.0 mm.

[0010] Preferably, it further comprises a first insulating portion, wherein the first insulating portion is attached to a side of the first cover plate facing the pole group;

[0011] When the first cover plate is covered on the housing, at least a portion of the first insulating portion extends into the housing, and the first insulating portion and at least a portion of the limit stopper are overlapped in the first direction.

[0012] Preferably, the outer walls on both sides of the first insulating portion in the second direction are provided with receiving grooves, and when the first cover plate is covered on the housing, the limit stopper is arranged in the receiving groove;

[0013] The difference between the size of the accommodating groove in the second direction and the size of the limit stopper in the second direction is h1, wherein 0.2 mm ≤ h1 ≤ 0.5 mm;

[0014] A difference between a size of the accommodating groove in the third direction and a size of the limiting block in the third direction is h2, wherein 0.2 mm ≤ h2 ≤ 0.5 mm, and the third direction is perpendicular to the second direction.

[0015] Preferably, the accommodating groove extends along the first direction, and the accommodating groove is open at one end of the first insulating portion facing the pole group.

[0016] Preferably, it further comprises a first pole, wherein the first pole and the explosion-proof valve are arranged on the first cover plate at an interval along the second direction.

[0017] Preferably, it further comprises a second pole and a second cover plate, wherein the second pole is arranged on the second cover plate, and the first cover plate and the second cover plate are respectively arranged to cover both ends of the housing in the first direction.

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

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

[0020] The battery cell provided in the present application is provided with limit blocks on both sides of the inner wall of the shell in the second direction, and the limit blocks are provided between the first cover plate and the electrode group, and the size of the limit blocks in the second direction is controlled. In other words, the height of the limit block is made greater than 1.5 times the gap between the shell and the pole group, so that the pole group can be effectively limited by the limit block, thereby preventing the pole group from moving in the first direction and blocking the explosion-proof valve on the first cover plate, thereby improving the safety of the battery cell.

[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 A schematic diagram of the isometric structure of a battery cell provided in an embodiment of the present application;

[0024] Figure 2 A schematic cross-sectional view of a battery cell according to an embodiment of the present application;

[0025] Figure 3 for Figure 2 A schematic diagram of the enlarged structure of the provided battery cell at D;

[0026] Figure 4 This is another isometric structural schematic diagram of the battery cell provided in an embodiment of the present application.

[0027] Reference numerals:

[0028] 1-shell; 11-limit block; 2-first cover plate; 21-explosion-proof valve; 22-first pole; 3-pole group; 4-first insulating part; 41-accommodating groove; 5-second cover plate; 51-second pole; 52-second insulating part.

[0029] F1-first direction; F2-second direction; F3-third direction. DETAILED DESCRIPTION

[0030] The following specific embodiments are provided to help the reader obtain a comprehensive understanding of the methods, devices and / or systems described herein. However, after understanding the disclosure of the present application, various changes, modifications and equivalents of the methods, devices and / or systems described herein will be apparent. For example, the order of operations described herein is merely an example, and is not limited to the order set forth herein, but in addition to the operations that must occur in a particular order, changes that will be apparent after understanding the disclosure of the present application may be made. In addition, in order to improve clarity and brevity, descriptions of features known in the art may be omitted.

[0031] The features described herein may be implemented in different forms and should not be interpreted as being limited to the examples described herein. Rather, the examples described herein have been provided only to illustrate some of the many possible ways of implementing the methods, devices and / or systems described herein that will be apparent after understanding the disclosure of the present application.

[0032] Throughout the specification, when an element (such as a layer, a region, or a substrate) is described as being “on”, “connected to”, “bound to”, “over”, or “covering” another element, it may be directly “on”, “connected to”, “bound to”, “over”, or “covering” another element, or one or more other elements may be present between them. In contrast, when an element is described as being “directly on”, “directly connected to”, “directly bound to”, “directly over”, or “directly covering” another element, there may be no other elements present between them.

[0033] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more items.

[0034] Although terms such as "first," "second," and "third" may be used herein to describe various members, components, regions, layers, or portions, these members, components, regions, layers, or portions are not limited by these terms. Rather, these terms are only used to distinguish one member, component, region, layer, or portion from another member, component, region, layer, or portion. Therefore, without departing from the teachings of the examples described herein, the first member, component, region, layer, or portion referred to may also be referred to as the second member, component, region, layer, or portion.

[0035] For ease of description, spatial relational terms such as "above", "upper", "below", and "lower" may be used herein to describe the relationship of one element to another element as shown in the accompanying drawings. Such spatial relational terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the accompanying drawings. For example, if the device in the accompanying drawings is turned over, an element described as being "above" or "upper" relative to another element will subsequently be "below" or "lower" relative to the other element. Therefore, the term "above" includes both "above" and "below" orientations depending on the spatial orientation of the device. The device may also be positioned in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relational terms used herein will be interpreted accordingly.

[0036] The terms used herein are only used to describe various examples and are not used to limit the present disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms "include", "comprise" and "have" list the stated features, quantities, operations, components, elements and / or their combinations that exist, but do not exclude the existence or addition of one or more other features, quantities, operations, components, elements and / or their combinations.

[0037] Variations in the shapes shown in the drawings may occur due to manufacturing techniques and / or tolerances. Therefore, the examples described herein are not limited to the specific shapes shown in the drawings but include variations in shapes that occur during manufacturing.

[0038] The features of the examples described herein may be combined in various ways that will be apparent after understanding the disclosure of the present application. In addition, although the examples described herein have various configurations, other configurations are possible as will be apparent after understanding the disclosure of the present application.

[0039] Refer to the following Figures 1 to 4 The battery cells and battery modules according to some embodiments of the present application are described.

[0040] See also Figures 1 to 4As shown, an embodiment of the first aspect of the present application provides a battery cell, which includes a shell 1, a first cover plate 2 and a pole group 3. The shell 1 is surrounded to form a space extending along a first direction F1. The first cover plate 2 is covered at one end of the shell 1 in the first direction F1. An explosion-proof valve 21 is provided on the first cover plate 2. Limit blocks 11 are provided on the inner walls on both sides of the shell 1 in the second direction F2. The pole group 3 is provided in the shell 1, and the limit block 11 is provided between the first cover plate 2 and the pole group 3. The second direction F2 intersects with the first direction F1. The dimension of the shell 1 in the second direction F2 is defined as A, the wall thickness of the shell 1 is defined as t, the dimension of the pole group 3 in the second direction F2 is defined as B, and the dimension of the limit block 11 in the second direction F2 is defined as C, wherein,

[0041] Table 1 shows that samples of pole groups 3 and limit blocks 11 of different sizes are prepared (at least 5 samples of each size are trial-produced), and the pole group 3 and the shell 1 are assembled, and the pole group 3 limiting test of the battery cell under thermal runaway state is carried out respectively. The results are shown in the following table.

[0042] Table 1:

[0043]

[0044]

[0045] According to Table 1, when When (i.e., samples No. 1 to 4), the shelling yield rate and / or the problem of poor positioning of the limit block 11 on the electrode group 3 occurred to varying degrees. When (i.e., sample No. 5 and sample No. 6), the five samples of each size can be well inserted into the shell and the limit stopper 11 can well limit the pole group 3 during the battery cell safety test (i.e., under thermal runaway condition).

[0046] In summary, according to the battery cell provided by the above technical features, the limit stoppers 11 are arranged on the inner walls of both sides of the housing 1 in the second direction F2, and the limit stoppers 11 are arranged between the first cover plate 2 and the electrode group 3, and the size of the limit stoppers 11 in the second direction F2 is controlled. Right now In other words, the height of the limit block 11 is made greater than 1.5 times the size of the gap between the shell 1 and the pole group 3 in the second direction F2, so that the pole group 3 can be effectively limited by the limit block 11, thereby preventing the pole group 3 from moving in the first direction F1 and blocking the explosion-proof valve 21 on the first cover plate 2, thereby improving the safety of the battery cell.

[0047] like Figures 1 to 4As shown, F1 shown in the figure may be an example of the first direction F1, and F2 shown in the figure may be an example of the second direction F2, wherein the first direction F1 and the second direction F2 intersect each other. Preferably, the first direction F1 and the second direction F2 are perpendicular to each other to accommodate most examples of square batteries. For ease of description, the direction perpendicular to the plane determined by the first direction F1 and the second direction F2 is defined as a third direction F3, and F3 shown in the figure may be an example of the third direction F3.

[0048] by Figures 1 to 4 Taking the example shown as an example, preferably, the first direction F1 may be the length direction of the square battery, the second direction F2 may be the width direction of the square battery, and the third direction F3 may be the thickness direction of the square battery.

[0049] However, it is not limited thereto. The first direction F1 may also be the width direction or thickness direction of the square battery. Correspondingly, the second direction F2 and the third direction F3 may be adaptively adjusted according to the first direction F1.

[0050] Preferably, if Figure 2 As shown, in the second direction F2, the total gap between the shell 1 and the pole group 3 (ie, A-2t-B) can be 1.0 mm to 1.6 mm, that is, 1.0 mm≤A-2t-B≤1.6 mm, to ensure smooth entry of the pole group 3 into the shell.

[0051] Preferably, if Figure 2 As shown, the size of the housing 1 in the second direction F2 (ie, the value A shown in the figure) can be 80 mm to 190 mm to accommodate the sizes of most square batteries.

[0052] Preferably, if Figure 3 As shown, the wall thickness of the shell 1 (ie, the t value shown in the figure) can be 0.3 mm to 1.0 mm to ensure the strength of the shell 1.

[0053] Preferably, if Figure 3 As shown, the above-mentioned limit stopper 11 can be integrally connected with the above-mentioned shell 1 to ensure the connection strength between the limit stopper 11 and the inner wall of the shell 1.

[0054] Preferably, if Figure 3 As shown, the above-mentioned limit stopper 11 can be formed by integrally stamping the housing 1 .

[0055] However, it is not limited to this, as long as the connection stability between the limit stop block 11 and the shell 1 is guaranteed, the connection method between the limit stop block 11 and the inner wall of the shell 1 is not limited to the example of integral stamping. For example, the limit stop block 11 and the shell 1 are welded together, or the limit stop block 11 and the shell 1 are bonded, etc.

[0056] Preferably, the limit stopper 11 may be a high temperature resistant part, such as a metal part, a ceramic part, etc.

[0057] In an embodiment, preferably, Figures 1 to 4 As shown, the battery cell may further include a first insulating portion 4 , which may be attached to a side of the first cover plate 2 facing the electrode group 3 , so as to achieve insulation between the first cover plate 2 and the electrode group 3 .

[0058] Preferably, if Figure 2 As shown, when the first cover plate 2 is covered on the housing 1 , at least a portion of the first insulating portion 4 extends into the housing 1 and overlaps with at least a portion of the limit stopper 11 to save space for the battery cell in the first direction F1 .

[0059] Preferably, if Figure 2 As shown, when the first cover plate 2 is covered on the shell 1, at least a portion of the first insulating portion 4 abuts against the electrode group 3, so that when the battery cell is in normal use, the electrode group 3 is limited by the first insulating portion 4 to ensure the stability of the battery cell in normal use.

[0060] Preferably, the first insulating portion 4 and the second insulating member described below may both be insulating plastic members.

[0061] Preferably, if Figures 1 to 4 As shown, the outer walls on both sides of the first insulating part 4 in the second direction F2 are provided with accommodating grooves 41. When the first cover plate 2 is covered on the shell 1, the limit block 11 is arranged in the accommodating groove 41, so as to reduce the space occupied by the limit block 11 in the battery cell.

[0062] Preferably, as shown in Table 2, the difference between the size of the accommodating groove 41 in the second direction F2 and the size of the limit block 11 in the second direction F2 is h1, wherein 0.2 mm ≤ h1 ≤ 0.5 mm. In other words, when the limit block 11 is disposed in the accommodating groove 41, a certain assembly gap is formed between the limit block 11 and the inner wall of the accommodating groove 41 in the second direction F2, so as to take into account both the smoothness of the limit block 11 being installed into the accommodating groove 41 and the strength of the first insulating part 4.

[0063] Similarly, as shown in Table 2, the difference between the size of the accommodating groove 41 in the third direction F3 and the size of the limit block 11 in the third direction F3 is h2, wherein 0.2 mm ≤ h2 ≤ 0.5 mm. In other words, when the limit block 11 is disposed in the accommodating groove 41, a certain assembly gap is formed between the limit block 11 and the inner wall of the accommodating groove 41 in the third direction F3, so as to take into account both the smoothness of the limit block 11 being installed into the accommodating groove 41 and the strength of the first insulating part 4.

[0064] Table 2 shows that samples were prepared with receiving grooves 41 and limit blocks 11 of different sizes, and the electrode group 3 and the housing 1 were assembled respectively. The results are shown in the following table.

[0065] Table 2:

[0066]

[0067] Preferably, if Figures 1 to 4 As shown, the receiving groove 41 extends along the first direction F1 , and the receiving groove 41 is open at one end of the first insulating part 4 facing the pole group 3 , so as to facilitate the assembly of the first insulating part 4 and the housing 1 .

[0068] In an embodiment, Figure 1 , Figure 2 and Figure 4 As shown, the battery cell may further include a first pole 22 , which is spaced apart from the explosion-proof valve 21 along the second direction F2 on the first cover plate 2 to prevent the first pole 22 from interfering with exhaust of the explosion-proof valve 21 .

[0069] Preferably, if Figure 1 , Figure 2 and Figure 4 As shown, the battery cell may further include a second cover plate 5 . The first cover plate 2 and the second cover plate 5 are respectively covered at two ends of the housing 1 in the first direction F1 to facilitate assembly of the battery cell.

[0070] Preferably, if Figure 2 and Figure 4 As shown, the battery cell may further include a second insulating portion 52 , which is attached to a side of the second cover plate 5 facing the electrode group 3 to achieve insulation between the second cover plate 5 and the electrode group 3 .

[0071] Similarly, the second insulating portion 52 may also abut against the electrode group 3 to limit the end of the electrode group 3 away from the first cover plate 2 .

[0072] Preferably, if Figure 1 , Figure 2 and Figure 4 As shown, the battery cell may further include a second pole 51 , and the second pole 51 may be disposed on the second cover plate 5 .

[0073] Optionally, not shown in the figure, the first pole and the second pole may both be arranged on the first cover plate.

[0074] Optionally, not shown in the figure, the first pole and the second pole may both be arranged on the second cover plate.

[0075] The embodiment of the second aspect of the present application further provides a battery module, comprising the battery cell described in any of the above embodiments, and thus having all the beneficial technical effects of the battery cell, which will not be elaborated here.

[0076] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The protection scope of the present application is not limited thereto. Although the present application is described in detail with reference to the above-described embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-described embodiments within the technical scope disclosed in the present application, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A battery cell, characterized in that: The invention comprises a shell, a first cover plate and a pole group, wherein the shell is enclosed to form a space extending in a first direction, the first cover plate is covered on one end of the shell in the first direction, an explosion-proof valve is arranged on the first cover plate, and limit stops are arranged on inner walls on both sides of the shell in a second direction, the pole group is arranged in the shell, and the limit stops are arranged between the first cover plate and the pole group, and the second direction intersects with the first direction; Define the size of the shell in the second direction as A, the wall thickness of the shell as t, the size of the pole group in the second direction as B, and the size of the limit stopper in the second direction as C, wherein, 2. The battery cell according to claim 1, characterized in that: 1.0mm≤A-2t-B≤1.6mm.

3. The battery cell according to claim 1, characterized in that: The size of the shell in the second direction is 80 mm to 190 mm.

4. The battery cell according to claim 1, characterized in that: The wall thickness of the shell is 0.3 mm to 1.0 mm.

5. The battery cell according to any one of claims 1 to 4, characterized in that: It also includes a first insulating portion, which is attached to a side of the first cover plate facing the pole group; When the first cover plate is covered on the housing, at least a portion of the first insulating portion extends into the housing, and the first insulating portion and at least a portion of the limit stopper are overlapped in the first direction.

6. The battery cell according to claim 5, characterized in that: The outer walls of both sides of the first insulating portion in the second direction are provided with receiving grooves, and when the first cover plate is covered on the housing, the limit stopper is arranged in the receiving groove; The difference between the size of the accommodating groove in the second direction and the size of the limit stopper in the second direction is h1, wherein 0.2 mm ≤ h1 ≤ 0.5 mm; A difference between a size of the accommodating groove in the third direction and a size of the limiting block in the third direction is h2, wherein 0.2 mm ≤ h2 ≤ 0.5 mm, and the third direction is perpendicular to the second direction.

7. The battery cell according to claim 6, characterized in that: The accommodating groove extends along the first direction, and the accommodating groove is opened at one end of the first insulating portion facing the pole group.

8. The battery cell according to claim 1, characterized in that: It also includes a first pole, and the first pole and the explosion-proof valve are arranged on the first cover plate along the second direction with an interval therebetween.

9. The battery cell according to claim 8, characterized in that: The second pole is provided on the second cover plate, and the first cover plate and the second cover plate are respectively provided on both ends of the housing in the first direction.

10. A battery module, characterized in that: A battery cell comprising the battery cell according to any one of claims 1 to 9.

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