Battery cell, battery pack, and electric device

Abstract

A battery cell, a battery pack, and an electric device. In the battery cell, a pressure relief hole (130) and an explosion-proof valve (200) are provided on the bottom wall (120) of a casing (100), and a first flow channel (121) and second flow channels (122) are provided on the bottom wall (120). The first flow channel (121) extends along the circumferential edge of the bottom wall (120) and is communicated with an accommodating cavity (110), and the second flow channels (122) are communicated between the first flow channel (121) and the pressure relief hole (130). Therefore, a gas discharging space is reserved at the bottom of the battery cell by means of the first flow channel (121) and the second flow channels (122). When the battery cell undergoes thermal runaway, uncontrolled gas flow can enter the second flow channels (122) through the first flow channel (121) at the edge, and converge at the pressure relief hole (130) from the second flow channels (122), to break through the pressure relief hole (130) to achieve pressure relief. In addition, related parameters of the second flow channels (122) and the pressure relief hole (130) satisfy 1<S / xlh≤65, so that during thermal runaway, the flow rate and pressure of the gas flow converging at the pressure relief hole (130) through the second flow channels (122) maintain moderate, and the valve breaking time for the gas flow to break through the explosion-proof valve (200) is moderate, thereby guaranteeing the stability and safety of the battery cell.

Description

Battery cells, battery packs and electrical equipment

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on February 4, 2024, with application number 202410160423.3 and application name “Battery Cell, Battery Pack and Electrical Equipment”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The embodiments of the present application relate to, but are not limited to, the field of battery technology. Background Art

[0003] Batteries are core components of electrical devices such as new energy vehicles, mobile phones, and laptops, making their safety performance particularly crucial. Currently, some batteries feature explosion-proof valves at the bottom. However, due to gravity, the electrode assembly and bottom support plate within the battery occupy the bottom space. This prevents airflow from converging on the explosion-proof valve in the event of thermal runaway, preventing timely pressure relief and thus compromising battery safety.

[0004] Summary of the Invention

[0005] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0006] According to a first aspect of the present application, an embodiment of the present application provides a battery cell, including:

[0007] A housing having a first direction, the housing being provided with a receiving cavity with an opening at one end, the housing comprising a bottom wall, the bottom wall being located at an end of the receiving cavity away from the opening and opposite to the opening along the first direction, the bottom wall being provided with a pressure relief hole extending through the bottom wall along the first direction;

[0008] an explosion-proof valve connected to the bottom wall and covering the pressure relief hole;

[0009] A first flow channel and a plurality of second flow channels are provided on a side of the bottom wall facing the accommodating cavity, wherein the first flow channel extends along a circumferential edge of the bottom wall and communicates with the accommodating cavity, and the plurality of second flow channels are spaced apart and arranged around the explosion-proof valve, wherein the second flow channels communicate with the pressure relief hole and the first flow channel;

[0010] The second flow channel includes a first surface and a second surface opposite to each other, the first surface and the second surface are connected to the hole wall of the pressure relief hole, the minimum distance between the first surface and the second surface is 1 mm, the number of the second flow channels is , the maximum dimension of the second flow channel along the first direction is h mm, and the minimum cross-sectional area of ​​the pressure relief hole perpendicular to the first direction is S mm 2 The battery cell satisfies:

[0011] In some embodiments, the battery cell satisfies:

[0012] In some embodiments, the battery cell satisfies: 75≤S≤1300.

[0013] In some embodiments, the battery cell satisfies: 0.1≤h≤1.8.

[0014] In some embodiments, among the plurality of second flow channels, at least some of the second flow channels include:

[0015] a main flow channel, one end of the main flow channel being connected to the pressure relief hole and the other end being connected to the first flow channel;

[0016] A branch flow channel, one end of which is connected to the main flow channel, and the other end of which is connected to the first flow channel.

[0017] In some embodiments, there are multiple branch flow channels, and the multiple branch flow channels all extend along the same direction.

[0018] In some embodiments, there are multiple branch flow channels, and the extension directions of at least two of the branch flow channels intersect.

[0019] In some embodiments, the plurality of second flow channels extend radiating from the pressure relief hole to the surrounding areas.

[0020] In some embodiments, the bottom wall comprises:

[0021] a convex portion, wherein the pressure relief hole and the second flow channel are both provided on the convex portion;

[0022] The peripheral portion is connected to the circumferential edge of the convex portion in a surrounding manner, and the convex portion is protruded toward the accommodating cavity relative to the peripheral portion.

[0023] In some embodiments, a groove is provided on a side of the bottom wall facing away from the accommodating cavity, and the peripheral portion and the convex portion form the groove.

[0024] In some embodiments, the housing further comprises:

[0025] A plurality of side walls are sequentially connected and surround the circumferential edge of the peripheral portion, the plurality of side walls are spaced apart from the convex portion, and the first flow channel is arranged between the convex portion and the plurality of side walls.

[0026] According to a second aspect of the present application, an embodiment of the present application provides a battery pack comprising the battery cell described in any of the above embodiments.

[0027] According to a third aspect of the present application, an embodiment of the present application provides an electrical device comprising the battery pack as described above.

[0028] The battery cell of the embodiment of the present application is provided with a pressure relief hole and an explosion-proof valve on the bottom wall of the shell, and a first flow channel and a second flow channel are provided on the bottom wall. The first flow channel extends along the circumferential edge of the bottom wall and is connected to the accommodating cavity, and the second flow channel is connected between the first flow channel and the pressure relief hole, thereby reserving exhaust space for the bottom of the battery cell through the first flow channel and the second flow channel. When the battery cell thermally runs away, the uncontrolled airflow can enter the second flow channel through the first flow channel at the edge, and converge at the pressure relief hole from the second flow channel, breaking through the pressure relief hole to achieve pressure relief; at the same time, the relevant parameters of the second flow channel and the pressure relief hole meet In the event of thermal runaway, the air flow rate and pressure of the airflow converging at the pressure relief hole through the second flow channel are moderate, and the time it takes for the airflow to break through the explosion-proof valve is moderate, thereby ensuring the stability and safety of the battery cell.

[0029] The battery pack of the embodiment of the present application may include all the technical features and beneficial effects of the above-mentioned battery cells, which will not be repeated here.

[0030] The electrical equipment of the embodiment of the present application may include all the technical features and beneficial effects of the above-mentioned battery pack, which will not be repeated here.

[0031] Still other aspects will become apparent upon reading and understanding the accompanying drawings and detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0033] FIG1 is an exploded schematic diagram of parts of a battery cell provided in an embodiment of the present application;

[0034] FIG2 is a schematic diagram of an exploded view of a battery cell according to an embodiment of the present application viewed from another angle;

[0035] FIG3 is a schematic diagram of the three-dimensional structure of the housing of the battery cell provided in the first embodiment of the present application;

[0036] FIG4 is a schematic diagram of the front structure of the housing of the battery cell in FIG3 ;

[0037] FIG5 is a schematic rear structural diagram of the housing of the battery cell in FIG4 ;

[0038] FIG6 is a schematic cross-sectional view of the structure along line AA in FIG5 ;

[0039] FIG7 is a schematic cross-sectional view of the structure along line BB in FIG5 ;

[0040] FIG8 is a schematic diagram of a partially enlarged structure of area A in FIG7 ;

[0041] FIG9 is a schematic diagram of the front structure of the housing of a battery cell provided in the second embodiment of the present application;

[0042] FIG10 is a schematic rear structural diagram of the housing of the battery cell in FIG9 ;

[0043] FIG11 is a schematic cross-sectional view of the structure along line CC in FIG10 ;

[0044] FIG12 is a schematic cross-sectional view of the structure along line DD in FIG10 ;

[0045] FIG13 is a schematic diagram of a partially enlarged structure of area B in FIG12;

[0046] Figure markings: 100-shell; 110-accommodating chamber; 111-opening; 120-bottom wall; 121-first flow channel; 122-second flow channel; 123-main flow channel; 124-branch flow channel; 125-first surface; 126-second surface; 127-convex portion; 128-peripheral portion; 129-groove; 130-pressure relief hole; 140-side wall; 200-explosion-proof valve; 300-top cover assembly; 400-electrode assembly; 500-support plate; 600-insulating film.

[0047] Implementation Methods of the Application

[0048] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0049] In the description of this application, it should be understood that the terms "length", "width", "thickness", "upper", "lower", "top", "bottom", "inner", "outer", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended only to facilitate the description of this application and simplify the description. They do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting this application. In the description of this application, "plurality" means two or more, and "at least one" means one, two, or more than two, unless otherwise clearly and specifically defined.

[0050] As a preface to this application, a battery cell is introduced, which has a structure with protruding positive / negative poles and a pressure relief device. This structural form has certain limitations on the electrical connection between batteries and the safety of exhaust. Therefore, a battery cell with a pressure relief device at the bottom of the aluminum shell came into being. However, the bottom pressure relief device requires that the bottom of the battery cell has sufficient exhaust space to ensure that the airflow in the shell cavity can converge at the position of the bottom pressure relief device. Due to the influence of gravity on the electrode assembly and the bottom support plate, the airflow often cannot converge at the pressure relief device, resulting in the inability to release pressure in time, affecting the safety performance of the battery cell.

[0051] In view of this, embodiments of the present application provide a battery cell to overcome at least one of the above-mentioned technical problems.

[0052] Please refer to FIG. 1 and FIG. 2 . It should be noted that, in the battery cell provided in the embodiment of the present application, the applicant mainly improved the structure of the shell 100 and the arrangement position of the explosion-proof valve 200 . The following focuses on the improved parts.

[0053] It should also be noted that, in addition to the improved structure described above, the battery cell may also include components such as a top cover assembly 300, an electrode assembly 400, a support plate 500, and an insulating film 600. The top cover assembly 300 is connected to the housing 100 and sealed at the opening of the housing 100. The electrode assembly 400 is disposed within the accommodating cavity 110 of the housing 100. The support plate 500 is disposed on the side of the electrode assembly 400 facing away from the top cover assembly 300 to support the electrode assembly 400 from below. The insulating film 600 is coated on the outside of the housing 100 to provide insulation protection.

[0054] Please refer to Figures 1 and 3 together. The shell 100 has a first direction X. The shell 100 is provided with a accommodating cavity 110 having an opening 111 at one end. The shell 100 includes a bottom wall 120. The bottom wall 120 is located at the end of the accommodating cavity 110 away from the opening 111 and is opposite to the opening 111 along the first direction X. That is, the opening 111 and the bottom wall 120 are respectively provided at opposite ends of the shell 100 in the first direction X. For the usual placement of the battery cell, the opening 111 is located at the upper end and the bottom wall 120 is located at the lower end.

[0055] It should be mentioned that, in the present invention, the first direction X is the height direction of the housing 100 , please refer to FIG. 1 to FIG. 2 for details.

[0056] The bottom wall 120 is provided with a pressure relief hole 130 extending through it along the first direction X. The explosion-proof valve 200 is connected to the bottom wall 120 and covers the pressure relief hole 130. In other words, the explosion-proof valve 200 of the pressure relief device of the battery cell targeted by this application exhausts gas toward the bottom.

[0057] In the embodiment of the present application, a first flow channel 121 and multiple second flow channels 122 are provided on the side of the bottom wall 120 facing the accommodating cavity 110. The first flow channel 121 extends along the circumferential edge of the bottom wall 120 and communicates with the accommodating cavity 110. In other words, the first flow channel 121 is an annular flow channel, circumferentially disposed around the edge of the bottom wall 120. Multiple second flow channels 122 are spaced apart from each other around the explosion-proof valve 200. The second flow channels 122 connect the pressure relief hole 130 and the first flow channels 121. In other words, the multiple second flow channels 122 are spaced apart from each other along the circumference of the pressure relief hole 130, and any two second flow channels 122 are spaced apart from each other. It should be noted that in the description of this application, a second flow channel 122 that communicates with the pressure relief hole 130 at one point is collectively referred to as a second flow channel 122. A second flow channel 122 may or may not be forked. Regardless of its structure, as long as it communicates with the pressure relief hole 130 at one point, it can be considered a second flow channel 122.

[0058] Specifically, referring to FIG4 , in the embodiment of the present application, the second flow channel 122 includes a first surface 125 and a second surface 126 opposite to each other, the first surface 125 and the second surface 126 are respectively connected to the hole wall of the pressure relief hole 130, the minimum spacing between the first surface 125 and the second surface 126 is 1 mm, the number of second flow channels 122 is x, the maximum dimension of the second flow channel 122 along the first direction X is h mm, and the minimum cross-sectional area of ​​the pressure relief hole 130 perpendicular to the first direction X is S mm 2 ;Battery monomers meet the following requirements:

[0059] By setting the relevant parameters of the second flow channel 122 and the pressure relief hole 130 to satisfy the above relationship, when the battery cell is in thermal runaway, the air flow rate and pressure of the airflow converging at the pressure relief hole 130 through the second flow channel 122 are moderate, so that the time it takes for the airflow to break through the explosion-proof valve is moderate, thereby ensuring the stability and safety of the battery cell.

[0060] Specifically, It can be any value among 1.1, 2.0, 6.0, 10, 20, 30, 40, 50, 65 or a range between any two values. When thermal runaway occurs, the battery cell valve rupture time is relatively fast, leaving the electric vehicle driver with too short a reaction time, the safety of the battery pack is reduced, which is not conducive to ensuring the driver's personal safety; when When the battery cell undergoes thermal runaway, the time it takes for the valve to rupture is relatively slow. Although this gives the electric vehicle driver more time to react, if the high-temperature gas inside the thermal runaway cell cannot be removed in time, the thermal runaway cell will explode or deflagrate, which will also reduce the safety of the battery pack and is not conducive to protecting the driver's personal safety. At this time, the flow rate and pressure of the airflow that converges at the pressure relief hole 130 through the second flow channel 122 are moderate, so that the time it takes for the airflow to break through the explosion-proof valve is moderate, thereby ensuring the stability and safety of the battery cell.

[0061] It should be noted that the number x of second flow channels 122 can be directly counted; as long as it is connected to the pressure relief hole 130 at one point, it can be considered as one second flow channel 122. For example, in the first and second embodiments of the present application, there are four second flow channels 122. In other embodiments, the number of second flow channels 122 can be set according to actual needs.

[0062] It should be noted that, in the present invention, the first flow channel 121 and the second flow channel 122 both refer to flow channel grooves, the first surface 125 and the second surface 126 are the two sidewalls of the second flow channel 122, and the minimum spacing l mm between the first surface 125 and the second surface 126, as well as the maximum dimension h mm of the second flow channel 122 along the first direction X, can both be measured using conventional measuring devices such as a vernier caliper or micrometer. The minimum spacing l between the first surface 125 and the second surface 126 is generally obtained by measuring the distance from the connection between the first surface 125 or the second surface 126 and the hole wall of the pressure relief hole 130 to the other opposite surface. That is, a perpendicular line is drawn from one of the connection points into the opposite opposite surface, the length of the perpendicular line is measured, and the length of the perpendicular line is used as the minimum spacing l. It should be noted that the other end of the perpendicular line should be within the opposing first surface 125 or second surface 126. If a perpendicular line drawn through the two connections to the opposing first surface 125 or second surface 126 does not fall within the opposing surface, the distance between the two connections between the first surface 125, the second surface 126, and the wall of the pressure relief hole 130 should be directly measured and used as the minimum distance l. For multiple second flow channels 122, after measuring the minimum distance l of each second flow channel 122, the minimum value is selected as the final minimum distance l.

[0063] It should be noted that the minimum cross-sectional area of ​​the pressure relief hole 130 along the first direction perpendicular to the first direction X is S mm 2 The area can be measured using conventional area measurement methods. When the minimum cross-section of the pressure relief hole 130 is a regular shape such as a circle or an ellipse, the area S can be measured and calculated using the area measurement method for regular shapes. When the minimum cross-section of the pressure relief hole 130 is an irregular shape, it can be measured and calculated using the coating method. That is, a coating with uniform mass is attached to the minimum cross-section, the coating attached to the corresponding part is removed, and the mass of the coating is determined. The quotient of the mass of the removed coating and the mass per unit area of ​​the predetermined coating is determined as the area S of the measured minimum cross-section.

[0064] Furthermore, in some embodiments, the battery cell satisfies:

[0065] That is, the minimum distance between the first surface 125 and the second surface 126 By controlling the minimum spacing within the above range, it is possible to further ensure that the airflow rate and pressure of the second flow channel 122 converging at the pressure relief hole 130 are moderate, thereby ensuring the safety of the battery cell, wherein π=3.14.

[0066] Specifically, in some embodiments, the battery cell satisfies: 75≤S≤1300.

[0067] That is, the minimum cross-sectional area S of the pressure relief hole 130 along the first direction perpendicular to the first direction X can be any value among 75, 100, 300, 500, 700, 900, 1100, 1300 or a range between any two values, in units of mm 2 , controlling the area of ​​the pressure relief hole 130 within the above range can meet the exhaust requirements of battery cells of most electrical equipment.

[0068] Specifically, in some embodiments, the battery cell satisfies: 0.1≤h≤1.8.

[0069] That is to say, the maximum dimension h of the second flow channel 122 along the first direction X can be any value among 0.1, 0.2, 0.4, 0.6, 0.7, 0.9, 1.0, 1.1, 1.2, 1.4, 1.5, 1.6, 1.7, 1.8, or a range value between any two values. By controlling h within this range, it can further ensure that the air flow rate and pressure of the second flow channel 122 converging at the pressure relief hole 130 are moderate, thereby ensuring the safety of the battery cell.

[0070] Please refer to Figures 4 to 6 and Figures 9 to 11. In both the first and second embodiments of the present application, multiple second flow channels 122 are included, wherein at least some of the second flow channels 122 include a main channel 123 and a branch channel 124. The main channel 123 is connected to the pressure relief hole 130 at one end and to the first flow channel 121 at the other end. The branch channel 124 is connected to the main channel 123 at one end and to the first flow channel 121 at the other end. By providing the branch channel 124, the airflow can pass through the first flow channel 121 and enter the second flow channel 122 more quickly and evenly, ensuring smooth pressure relief and improving safety.

[0071] Furthermore, in some embodiments, multiple branch channels 124 are provided; the multiple branch channels 124 all extend in the same direction, or the extension directions of at least two branch channels 124 intersect. For example, in the first embodiment, the branch channels 124 are connected to the main channel 123 in a divergent manner, and their extension directions necessarily intersect. In the second embodiment, the branch channels 124 all extend in a direction perpendicular to the main channel 123. By properly setting the extension direction of the branch channels 124, the uniformity of the distribution of the second channel 122 around the first channel 121 can be improved, thereby ensuring smooth exhaust and further enhancing safety.

[0072] Referring again to FIG. 4 , in some embodiments, multiple second flow channels 122 extend in a divergent pattern around the pressure relief hole 130. This allows the second flow channels 122 to be evenly distributed around the first flow channel 121. Airflow from all areas around the first flow channel 121 can quickly enter the second flow channels 122 and converge into the pressure relief hole 130, improving safety.

[0073] Please refer to Figures 5 to 8 and Figures 10 to 13. In some embodiments, the bottom wall 120 includes a protrusion 127 and a peripheral portion 128. The pressure relief hole 130 and the second flow channel 122 are both provided on the protrusion 127. The peripheral portion 128 is connected to the circumferential edge of the protrusion 127. The protrusion 127 is protruded toward the accommodating cavity 110 relative to the peripheral portion 128.

[0074] Furthermore, a groove 129 is provided on the side of the bottom wall 120 facing away from the accommodating cavity 110. The peripheral portion 128 and the protrusion 127 form the groove 129. In other words, the groove 129 is formed by the protrusion 127 and the groove 129, and is provided on the side of the protrusion 127 away from the groove 129. The provision of the groove 129 prevents the bottom wall 120 from being too thick at the protrusion 127, thereby reducing the weight of the battery cell.

[0075] Furthermore, the housing 100 further includes:

[0076] The plurality of side walls are sequentially connected and surround the circumferential edge of the peripheral portion 128 . The plurality of side walls are spaced apart from the convex portion 127 . The first flow channel 121 is disposed between the convex portion 127 and the plurality of side walls.

[0077] Next, specific embodiments of the battery cells of the present application are provided, and the present application is described in more detail through the specific embodiments. It can be seen from the following embodiments that, in actual implementation, when the battery cells satisfy the relationship of the present application, their safety is in an optimal state.

[0078] Example 1: The battery cell is a square lithium iron phosphate battery (in other embodiments, a ternary battery, a sodium ion battery, a solid-state or semi-solid-state battery type may also be used), and the poles of each battery cell are arranged on the top cover assembly 300, the pressure relief hole 130 and the explosion-proof valve 200 are arranged on the bottom wall 120 of the shell 100, and the electrode assembly 400 and the support plate 500 are arranged in the shell 100. The support plate 500 is located between the bottom wall 120 and the electrode assembly 400, and the electrode assembly 400 is supported by the support plate 500.

[0079] The structures of Examples 2 to 10 and Comparative Examples 1 to 3 are substantially the same as that of Example 1, except for the values ​​of the relevant parameters of the second flow channel 122 and the pressure relief hole 130 .

[0080] The details are as follows:

[0081] From the table above we can see that:

[0082] when When thermal runaway occurs, the battery cell valve rupture time is relatively fast. Specifically, the time taken for comparative example 2 to rupture the valve is only 5.3s. The battery cell valve rupture time is relatively fast, which leaves too little reaction time for the electric vehicle driver, reduces the safety of the battery pack, and is not conducive to ensuring the driver's personal safety.

[0083] when When the battery cell undergoes thermal runaway, the valve rupture time of the battery cell is relatively slow. Specifically, the time taken for the battery cell to rupture during thermal runaway is 20s and 18.7s respectively. Although the battery cell rupture time is relatively slow, which gives the electric vehicle driver more reaction time, if the high-temperature gas inside the thermal runaway battery cell cannot be removed in time, the thermal runaway battery cell will explode or deflagrate, which also reduces the safety of the battery pack and is not conducive to ensuring the personal safety of the driver.

[0084] when Specifically looking at Examples 1 to 10, the battery cell valve rupture time when thermal runaway occurs is between 14s and 16.2s, and the valve rupture time when the airflow breaks through the explosion-proof valve is moderate, thereby ensuring the stability and safety of the battery cell and giving the electric vehicle driver relatively more reaction time to escape.

[0085] Accordingly, an embodiment of the present application provides a battery pack, which includes a battery cell of any of the above embodiments. It can be understood that the battery pack can include all the technical features and beneficial effects of the above battery cells, which will not be repeated here.

[0086] Accordingly, an embodiment of the present application provides an electrical device, which may be various types of equipment such as new energy vehicles, computers, energy storage and power supply devices, etc. It can be understood that the electrical device may include all the technical features and beneficial effects of the above-mentioned battery pack, which will not be repeated here.

[0087] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0088] The above is a detailed introduction to the battery pack and electrical equipment provided in the embodiments of the present application, and specific examples are used to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the technical solutions and core ideas of the present application; ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein; and 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 battery cell, wherein: include: A housing having a first direction, the housing being provided with a receiving cavity with an opening at one end, the housing comprising a bottom wall, the bottom wall being located at an end of the receiving cavity away from the opening and opposite to the opening along the first direction, the bottom wall being provided with a pressure relief hole extending through the bottom wall along the first direction; an explosion-proof valve connected to the bottom wall and covering the pressure relief hole; A first flow channel and a plurality of second flow channels are provided on a side of the bottom wall facing the accommodating cavity, wherein the first flow channel extends along a circumferential edge of the bottom wall and communicates with the accommodating cavity, and the plurality of second flow channels are spaced apart and arranged around the explosion-proof valve, wherein the second flow channels communicate with the pressure relief hole and the first flow channel; The second flow channel includes a first surface and a second surface opposite to each other, the first surface and the second surface are connected to the hole wall of the pressure relief hole, the minimum distance between the first surface and the second surface is 1 mm, the number of the second flow channels is x, the maximum dimension of the second flow channel along the first direction is h mm, and the minimum cross-sectional area of the pressure relief hole perpendicular to the first direction is S mm 2 The battery cell satisfies:

2. The battery cell according to claim 1, wherein: The battery cell also meets the following requirements:

3. The battery cell according to claim 1, wherein: The battery cell also meets the following requirements:

4. The battery cell according to claim 1, wherein: The battery cell also meets the following requirements:

5. The battery cell according to claim 1, wherein The battery cell further satisfies: 75≤S≤1300. The battery cell according to claim 1 , wherein: The battery cell also satisfies: 0.1≤h≤1.

8.

7. The battery cell according to claim 1, wherein: Among the plurality of second flow channels, at least some of the second flow channels include: a main flow channel, one end of the main flow channel being connected to the pressure relief hole and the other end being connected to the first flow channel; A branch flow channel, one end of which is connected to the main flow channel, and the other end of which is connected to the first flow channel.

8. The battery cell according to claim 7, wherein: There are multiple branch flow channels, and the multiple branch flow channels extend along the same direction.

9. The battery cell according to claim 7, wherein: There are multiple branch flow channels, and the extension directions of at least two of the branch flow channels intersect.

10. The battery cell according to claim 1, wherein The plurality of second flow channels extend divergently around the pressure relief hole.

11. The battery cell according to claim 1, wherein The bottom wall comprises: a convex portion, wherein the pressure relief hole and the second flow channel are both provided on the convex portion; The peripheral portion is connected to the circumferential edge of the convex portion in a surrounding manner, and the convex portion is protruded toward the accommodating cavity relative to the peripheral portion.

12. The battery cell according to claim 11, wherein: A groove is provided on a side of the bottom wall facing away from the accommodating cavity, and the peripheral portion and the convex portion form the groove.

13. The battery cell according to claim 11, wherein: The housing further comprises: A plurality of side walls are sequentially connected and surround the circumferential edge of the peripheral portion, the plurality of side walls are spaced apart from the convex portion, and the first flow channel is arranged between the convex portion and the plurality of side walls.

14. A battery pack, wherein: The invention comprises the battery cell according to any one of claims 1 to 13.

15. An electrical device, wherein: Comprising the battery pack as claimed in claim 14.

Images