Battery cell and power supply device

Abstract

A battery cell and a power supply device. The battery cell comprises a housing (101) and an explosion-proof valve (102); the housing (101) comprises a plurality of side walls, and the plurality of side walls define a cylindrical structure; the explosion-proof valve (102) is mounted on one of the side walls; the thickness of the side wall where the explosion-proof valve (102) is mounted is less than or equal to the thickness of the rest side walls, and the thickness of the side wall where the explosion-proof valve (102) is mounted is less than or equal to a preset thickness, so that the side wall deforms under a preset pressure, thereby generating a force for opening the explosion-proof valve (102). According to the battery cell, the thickness of the side wall where the explosion-proof valve (102) is mounted is less than or equal to the thickness of the rest side walls, so that on the one hand, the weight of the housing (101) can be further reduced, and on the other hand, the side wall is prone to deform to generate a force for pulling the explosion-proof valve (102), and a positive effect on quick opening of the explosion-proof valve (102) is achieved.

Description

Battery cells and power supply devices

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the China Patent Office on June 28, 2023, with application number 202321674898.1 and invention name “Battery Cell and Power Supply Device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of lithium-ion batteries, and in particular to a battery cell and a power supply device. Background Art

[0004] The pressure relief mechanism on lithium-ion batteries has a significant impact on their safety performance. For example, when a lithium-ion battery experiences a short circuit or overcharge, thermal runaway can occur, causing a sudden increase in internal pressure. At this point, a pressure relief mechanism is needed to release this internal pressure to prevent the battery from exploding.

[0005] The cell casing of a lithium-ion battery includes multiple sidewalls, one of which houses the pressure relief mechanism. These sidewalls are uniformly thick, increasing the weight of the cell and reducing the effective internal space, resulting in poor internal space utilization and a lower energy density.

[0006] Summary of the Invention

[0007] The purpose of the present application is to provide a battery cell and a power supply device, which can reduce the weight of the housing and facilitate the opening of the explosion-proof valve.

[0008] The present application provides a battery cell, comprising a housing and an explosion-proof valve;

[0009] The shell includes a plurality of side walls, and the plurality of side walls are arranged to form a cylindrical structure;

[0010] The explosion-proof valve is installed on one of the side walls, the thickness of the side wall on which the explosion-proof valve is installed is less than or equal to the thickness of the other side walls, and the thickness of the side wall on which the explosion-proof valve is installed is less than or equal to a preset thickness, so as to deform under a preset pressure, thereby generating an opening force on the explosion-proof valve.

[0011] In the above technical solution, further, the side wall on which the explosion-proof valve is installed is a first wall, and the thickness of the first wall is d1, d1≤0.6mm;

[0012] The remaining side walls are second walls, and the thickness of the second walls is d2, 0mm≤d2-d1≤2mm.

[0013] In the above technical solution, further, the thickness of the explosion-proof valve is e,

[0014] In the above technical solution, further, the cylindrical structure is a rectangular cylindrical structure;

[0015] The number of the first wall is one, the number of the second walls is three, and the area of ​​the outer surface of the first wall is smaller than or equal to the area of ​​the outer surface of the second wall connected to the first wall.

[0016] In the above technical solution, further, the length direction of the side connecting the first wall and the second wall is the length direction of the first wall, and the length direction of the explosion-proof valve is in the same direction as the length direction of the first wall;

[0017] In the length direction of the first wall, the distance between the edge of the explosion-proof valve and the edge of the first wall is s1, s1 ≥ 3.5 mm;

[0018] And / or, in the width direction of the first wall, a distance between an edge of the explosion-proof valve and an edge of the first wall is s2, and s2 is ≥ 10 mm.

[0019] In the above technical solution, further, the length of the explosion-proof valve is L, the width of the explosion-proof valve is B,

[0020] In the above technical solution, further, the shell also includes a positive electrode cover plate and a negative electrode cover plate, and the positive electrode cover plate and the negative electrode cover plate are respectively installed at the openings at both ends of the cylindrical structure to enclose and form a accommodating cavity for accommodating the bare battery cell.

[0021] In the above technical solution, further comprising a support plate;

[0022] The support plate is arranged between the side wall on which the explosion-proof valve is installed and the bare battery core, and a channel is opened on the support plate.

[0023] In the above technical solution, further comprising an insulating protective film;

[0024] The insulating protective film is wrapped around the side of the bare cell, and the support plate is wrapped inside the insulating protective film.

[0025] The present application also provides a power supply device, comprising the battery cell described in the above solution.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] The battery cell provided in the present application is provided with a side wall on which an explosion-proof valve is installed, and the thickness of the side wall is less than or equal to the thickness of the other side walls. On the one hand, this can further reduce the weight of the shell. On the other hand, the side wall is easily deformed to generate a force pulling the explosion-proof valve, which has a positive effect on the rapid opening of the explosion-proof valve.

[0028] The present application also provides a power supply device, including the battery cell described in the above solution. Based on the above analysis, it can be seen that the power supply device also has the above beneficial effects, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. 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 any creative work.

[0030] FIG1 is a schematic diagram of the sidewall expansion force provided by the present application;

[0031] FIG2 is a schematic structural diagram of a cylindrical structure provided by the present application;

[0032] FIG3 is a first structural schematic diagram of a battery cell provided in this application;

[0033] FIG4 is a second structural schematic diagram of a battery cell provided in this application.

[0034] In the figure: 101 - shell; 102 - explosion-proof valve; 103 - mounting hole; 104 - notch; 105 - first wall; 106 - second wall; 107 - positive electrode cover; 108 - negative electrode cover; 109 - support plate; 110 - insulating protective film. DETAILED DESCRIPTION

[0035] The following will clearly and completely describe the technical solution of this application in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0036] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of this application and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0037] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0038] Example 1

[0039] The battery cell provided herein includes a housing 101 and at least one explosion-proof valve 102 mounted on the housing 101. When the internal pressure of the battery structure increases to a certain level, the explosion-proof valve 102 is opened to drain the internal electrolyte or other substances, thereby reducing the internal pressure of the battery structure and preventing battery explosion.

[0040] Referring to Figures 1 to 4, specifically, the shell 101 includes multiple side walls, which are arranged to form a cylindrical structure, so that they can be mounted on the side of the bare cell of the battery cell to protect the bare cell. One of the side walls is provided with a mounting hole 103, and the explosion-proof valve 102 can be welded and installed in the mounting hole 103 of the side wall to achieve the installation and fixation of the explosion-proof valve 102. The thickness of the side wall on which the explosion-proof valve 102 is installed is less than or equal to the thickness of the other side walls, which can reduce the weight of the shell 101. The thickness of the side wall on which the explosion-proof valve 102 is installed is less than or equal to the preset thickness, so that the side wall is deformed under a preset pressure to generate an opening force on the explosion-proof valve 102.

[0041] Specifically, when the internal pressure of the bare battery cell arranged in the shell 101 is large and exceeds the threshold of the explosion-proof valve 102, the side wall on which the explosion-proof valve 102 is installed is thinner, and the side wall is more likely to deform to expand and bulge outward. The lateral force generated by the deformation of the side wall (force F1 shown in Figure 1) will generate a lateral pulling force (force F2 shown in Figure 1) on the notch 104 of the explosion-proof valve 102. That is, in addition to the vertical pressure generated by the internal airflow (force F3 shown in Figure 1), the explosion-proof valve 102 is also subjected to a tensile force with a "tearing" effect caused by the deformation of the side walls in all directions, so that the explosion-proof valve 102 can be opened quickly and the pressure of the bare battery cell inside can be released in time.

[0042] The battery cell provided in the present application is provided with a side wall on which the explosion-proof valve 102 is installed, and the thickness of the side wall is less than or equal to the thickness of the other side walls. On the one hand, this can further reduce the weight of the shell 101. On the other hand, the side wall is easily deformed to generate a force pulling the explosion-proof valve 102, which has a positive effect on the rapid opening of the explosion-proof valve 102.

[0043] In an optional solution of this embodiment, the side wall on which the explosion-proof valve 102 is installed is the first wall 105, and the thickness of the first wall 105 is d1, d1≤0.6mm; the remaining side walls are the second wall 106, and the thickness of the second wall 106 is d2; 0mm≤d2-d1≤2mm. The thickness of the first wall 105 and the second wall 106 is relatively thin, which can reduce the weight of the shell 101.

[0044] Furthermore, the thickness of the explosion-proof valve 102 is e, The thickness of the explosion-proof valve 102 has the above relationship with the thickness of the first wall 105, so that when the internal pressure of the bare battery cell exceeds the threshold of the explosion-proof valve 102, the first wall 105 can deform accordingly to simultaneously generate a force to open the explosion-proof valve 102, so that the explosion-proof valve 102 can be opened quickly.

[0045] In an optional solution of this embodiment, the cylindrical structure is a rectangular cylindrical structure, the number of the first wall 105 is one, the number of the second walls 106 is three, one of the second walls 106 is the same shape as the first wall 105 and is positioned opposite to it, two of the second walls 106 are connected to the first wall 105, and the area of ​​the outer surface of the first wall 105 is less than or equal to the area of ​​the outer surface of the second wall 106 connected to it.

[0046] In this embodiment, as shown in FIG2 , the tubular structure is specifically a rectangular tubular structure with a rectangular cross-sectional profile. The side wall on which the explosion-proof valve 102 is installed is a first wall 105 with a smaller plate area. When the internal pressure of the bare battery cell increases, the deformation degree of the first wall 105 is higher, and it is easier to generate a pulling force with a "pulling" effect.

[0047] 2 , the length direction of the side connecting the first wall 105 and the second wall 106 is the length direction of the first wall 105. The two explosion-proof valves 102 are spaced apart along the length direction of the first wall 105, and the length directions of the two explosion-proof valves 102 are in the same direction as the length direction of the first wall 105. Specifically, the length of the explosion-proof valve 102 is L, the width of the explosion-proof valve 102 is B,

[0048] Optionally, in the length direction of the first wall 105, the distance between the edge of the explosion-proof valve 102 and the edge of the first wall 105 is s1, s1 ≥ 3.5 mm; in the width direction of the first wall 105, the distance between the edge of the explosion-proof valve 102 and the edge of the first wall 105 is s2, s2 ≥ 10 mm, which can ensure that the connection between the explosion-proof valve 102 and the first wall 105 is stable, so that the explosion-proof valve 102 can be reliably installed on the first wall 105.

[0049] Example 2

[0050] The battery cell in the second embodiment is an improvement on the above embodiment. The technical contents disclosed in the above embodiment will not be described repeatedly. The contents disclosed in the above embodiment also belong to the contents disclosed in the second embodiment.

[0051] As shown in Figures 3 and 4 , in an optional solution of this embodiment, the housing 101 further includes a positive electrode cover plate 107 and a negative electrode cover plate 108. The positive electrode cover plate 107 and the negative electrode cover plate 108 are respectively installed at the openings at both ends of the cylindrical structure to enclose a cavity for accommodating the bare battery cell. The positive electrode cover plate 107 and the negative electrode cover plate 108 are both electrically connected to the bare battery cell to enable electrical connection between the bare battery cell and other external electrical components.

[0052] In an optional solution of this embodiment, when the battery cells are actually placed, the side wall with the explosion-proof valve 102 is oriented downward. A support plate 109 is provided between the side wall with the explosion-proof valve 102 and the bare battery cells to support the bare battery cells and prevent the bare battery cells from clinging tightly to the first wall 105 and affecting the opening of the explosion-proof valve 102. The support plate 109 also defines a channel to allow the electrolyte or other substances inside to be ejected sequentially through the channel and the explosion-proof valve 102.

[0053] In an optional solution of this embodiment, the battery cell further includes an insulating protective film 110; the insulating protective film 110 is wrapped around the side of the bare cell, and the support plate 109 is wrapped in the insulating protective film 110. The insulating protective film 110 can improve the insulation performance of the battery cell and prevent short circuits.

[0054] Example 3

[0055] Embodiment 3 of the present application provides a power supply device, including a battery cell of any of the above embodiments, and thus has all the beneficial technical effects of the battery cell of any of the above embodiments, which will not be repeated here.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application. In addition, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments means that they are within the scope of the present application and form different embodiments.

Claims

1. A battery cell, characterized in that: Including a shell and an explosion-proof valve; The shell includes a plurality of side walls, and the plurality of side walls are arranged to form a cylindrical structure; The explosion-proof valve is installed on one of the side walls, the thickness of the side wall on which the explosion-proof valve is installed is less than or equal to the thickness of the other side walls, and the thickness of the side wall on which the explosion-proof valve is installed is less than or equal to a preset thickness, so as to deform under a preset pressure, thereby generating an opening force on the explosion-proof valve.

2. The battery cell according to claim 1, characterized in that: The side wall on which the explosion-proof valve is installed is a first wall, and the thickness of the first wall is d1, d1≤0.6mm; The remaining side walls are second walls, and the thickness of the second wall is d2, 0mm≤d2-d1≤2mm.

3. The battery cell according to claim 2, characterized in that: The thickness of the explosion-proof valve is e, 4. The battery cell according to claim 2, characterized in that: The cylindrical structure is a rectangular cylindrical structure; The number of the first walls is one, the number of the second walls is three, and the area of ​​the outer surface of the first wall is smaller than or equal to the area of ​​the outer surface of the second wall connected to the first wall.

5. The battery cell according to claim 4, characterized in that: The length direction of the side connecting the first wall and the second wall is the length direction of the first wall, and the length direction of the explosion-proof valve is in the same direction as the length direction of the first wall; In the length direction of the first wall, the distance between the edge of the explosion-proof valve and the edge of the first wall is s1, s1 ≥ 3.5 mm; And / or, in the width direction of the first wall, the distance between the edge of the explosion-proof valve and the edge of the first wall is s2, and s2≥10 mm.

6. The battery cell according to claim 4, characterized in that: The length of the explosion-proof valve is L, the width of the explosion-proof valve is B, 7. The battery cell according to claim 1, characterized in that: The shell also includes a positive electrode cover plate and a negative electrode cover plate, and the positive electrode cover plate and the negative electrode cover plate are respectively installed at the openings at both ends of the cylindrical structure to enclose and form a receiving cavity for receiving the bare battery cell.

8. The battery cell according to claim 7, characterized in that: Also included is a support plate; The support plate is arranged between the side wall on which the explosion-proof valve is installed and the bare battery core, and the support plate is provided with a channel.

9. The battery cell according to claim 8, characterized in that: Also includes insulating protective film; The insulating protective film is wrapped around the side of the bare battery core, and the support plate is wrapped inside the insulating protective film.

10. A power supply device, characterized in that: The invention comprises the battery cell according to any one of claims 1 to 9.

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