Battery monomer and battery pack

Abstract

The utility model provides a battery monomer and a battery pack, and belongs to the technical field of batteries. Each battery monomer comprises a shell, a top cover plate and an anti-explosion valve; the shell is provided with a containing cavity with an opening; the top cover piece is connected to the shell and covers the opening, and the top cover piece is provided with a mounting hole penetrating through the top cover piece in the thickness direction of the top cover piece; the anti-explosion valve comprises an anti-explosion valve body and a mounting part; the mounting part is connected to the explosion-proof valve body in a surrounding manner and is connected to the hole wall of the mounting hole; the explosion-proof valve body is provided with a weak part, and the weak part is used for releasing the pressure when the internal pressure of the battery monomer reaches a threshold value; and the weak part is sunken or arched along the thickness direction of the top cover sheet to form a buffer body. The single battery provided by the utility model can release residual stress and strain generated in the welding process of the mounting part and the shell of the battery, and can avoid deformation of the anti-explosion valve body caused by stress pulling in the mounting process, so that the safety and reliability of the battery are remarkably improved.

Description

Technical Field

[0001] This application relates to the technical field of batteries, and particularly to a battery cell and a battery pack. Background Art

[0002] As a key component of power batteries, the structure of the power battery top cover has a significant impact on the energy density, economy, and safety of power batteries. An explosion-proof valve is provided on the power battery top cover to be able to open and release the internal pressure in a timely manner when the battery cell abnormally generates gas and the internal pressure increases sharply, preventing the occurrence of battery cell explosion.

[0003] Currently, in the production process of the top cover and the battery cell, laser welding is used as the connection method. Among them, the assembly of the top cover and the explosion-proof valve is welded around the outer circumference of the explosion-proof valve, and the assembly of the top cover into the battery cell is welded around the outer circumference of the top cover. Since the thickness of the explosion-proof valve notch is significantly thinner than that of the explosion-proof valve body, and the notch position is a plane, laser welding will generate residual stress and strain at the welding joint position, resulting in the explosion-proof valve notch being stressed and pulled or even deformed, making the explosion-proof valve bursting value unstable, and even having a risk of cracking during the manufacturing process and working conditions. Summary of the Utility Model

[0004] In view of this, the purpose of this application is to overcome the deficiencies in the prior art and provide a battery cell and a battery pack.

[0005] In a first aspect, this application provides a battery cell, including:

[0006] A housing having an open receiving cavity;

[0007] A top cover plate connected to the housing and covering the opening, the top cover plate having a mounting hole penetrating through the top cover plate in the thickness direction of the top cover plate;

[0008] An explosion-proof valve, including an explosion-proof valve body and a mounting portion;

[0009] The mounting portion is connected around the explosion-proof valve body, and the mounting portion is connected to the hole wall of the mounting hole;

[0010] The explosion-proof valve body is provided with a weak portion for releasing the pressure when the internal pressure of the battery cell reaches a threshold value;

[0011] Part of the weak portion is recessed or arched in the thickness direction of the top cover plate to form a buffer body.

[0012] In some embodiments, a plurality of the buffer bodies are provided on the weak portion, and the plurality of buffer bodies are arranged continuously or at intervals.

[0013] In some embodiments, the weak part has a central line area in the width direction of the weak part trajectory, and a plurality of the buffer bodies are all arranged in the central line area.

[0014] In some embodiments, the buffer body includes a first wall surface and a second wall surface which are oppositely arranged, and the buffer body is formed by a partial depression of the first wall surface;

[0015] Or, the buffer body is formed by a partial arching of the first wall surface.

[0016] In some embodiments, along the trajectory direction of the weak part, a plurality of the buffer bodies are arranged at equal intervals.

[0017] In some embodiments, the buffer body includes an inner wall surface and an outer wall surface which are oppositely arranged, and both the inner wall surface and the outer wall surface are semi-spherical surfaces.

[0018] In some embodiments, along the thickness direction of the top cover sheet, the thickness of the installation part is greater than the thickness of the explosion-proof valve body.

[0019] In some embodiments, the weak part includes a first straight line segment and a second straight line segment;

[0020] The first straight line segment intersects with the second straight line segment to form an intersection point, and the intersection point is located at the centroid position of the explosion-proof valve body.

[0021] In some embodiments, the weak part includes a first curve segment and a second curve segment;

[0022] The first curve segment and the second curve segment are axially symmetrically arranged with respect to the central line in the width direction of the explosion-proof valve body, and / or the first curve segment and the second curve segment are axially symmetrically arranged with respect to the central line in the length direction of the explosion-proof valve body.

[0023] In a second aspect, the present application provides a battery pack, including the battery cell described above.

[0024] The embodiments of the present application have the following advantages: The battery cell provided by the present application is provided with buffer bodies at the weak parts of the explosion-proof valve body, so that the buffer bodies can release the residual stress and strain generated during the welding process of the installation part and the battery housing, enhance the anti-deformation ability of the notch of the explosion-proof valve body, and at the same time can avoid the deformation of the explosion-proof valve body caused by stress pulling during the installation process, thereby significantly improving the safety and reliability of the battery.

[0025] To make the above objects, features and advantages of the present application more obvious and understandable, the following specifically gives preferred embodiments and, in conjunction with the accompanying drawings, makes a detailed description as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] To more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation of the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0027] Figure 1 The structural schematic diagram of a perspective view of a battery cell provided by some embodiments of the present application is shown;

[0028] Figure 2 The structural schematic diagram of a perspective view of a top cover sheet in a battery cell provided by some embodiments of the present application is shown;

[0029] Figure 3 The structural schematic diagram of a perspective view of a first embodiment of an explosion-proof valve in a battery cell provided by some embodiments of the present application is shown;

[0030] Figure 4 The structural schematic diagram of another perspective view of a first embodiment of an explosion-proof valve in a battery cell provided by some embodiments of the present application is shown;

[0031] Figure 5 Shown is Figure 4 The cross-sectional view of the A-A part in;

[0032] Figure 6 Shown is Figure 4 The cross-sectional view of the B-B part in;

[0033] Figure 7 Shown is Figure 6 The enlarged view of the B' part in;

[0034] Figure 8 The structural schematic diagram of a perspective view of a second embodiment of an explosion-proof valve in a battery cell provided by some embodiments of the present application is shown;

[0035] Figure 9 The structural schematic diagram of another perspective view of a second embodiment of an explosion-proof valve in a battery cell provided by some embodiments of the present application is shown;

[0036] Figure 10 Shown is Figure 9 The cross-sectional view of the C-C part in;

[0037] Figure 11 Shown is Figure 9 The cross-sectional view of the D-D part in;

[0038] Figure 12Shows a schematic structural view of a third embodiment of an explosion-proof valve in a battery cell provided by some embodiments of the present application from one perspective;

[0039] Figure 13 Shows a schematic structural view of a third embodiment of an explosion-proof valve in a battery cell provided by some embodiments of the present application from another perspective;

[0040] Figure 14 Shows Figure 13 A cross-sectional view of the E-E part in;

[0041] Figure 15 Shows Figure 13 A cross-sectional view of the F-F part in;

[0042] Figure 16 Shows a schematic structural view of a fourth embodiment of an explosion-proof valve in a battery cell provided by some embodiments of the present application from one perspective;

[0043] Figure 17 Shows a schematic structural view of a fourth embodiment of an explosion-proof valve in a battery cell provided by some embodiments of the present application from another perspective;

[0044] Figure 18 Shows Figure 17 A cross-sectional view of the G-G part in;

[0045] Figure 19 Shows Figure 17 A cross-sectional view of the H-H part in;

[0046] Figure 20 Shows a schematic structural view of a fifth embodiment of an explosion-proof valve in a battery cell provided by some embodiments of the present application from one perspective;

[0047] Figure 21 Shows a schematic structural view of a fifth embodiment of an explosion-proof valve in a battery cell provided by some embodiments of the present application from another perspective;

[0048] Figure 22 Shows Figure 20 A cross-sectional view of the I-I part in;

[0049] Figure 23 Shows Figure 20 A cross-sectional view of the J-J part in;

[0050] Figure 24 Shows Figure 23 An enlarged view of the J' part in;

[0051] Figure 25 Shows a schematic structural view of a sixth embodiment of an explosion-proof valve in a battery cell provided by some embodiments of the present application from one perspective;

[0052] Figure 26 Shows a schematic structural view of another perspective of the sixth embodiment of the explosion-proof valve in a battery cell provided by some embodiments of the present application;

[0053] Figure 27 Shows Figure 26 A cross-sectional view of the K-K part in;

[0054] Figure 28 Shows Figure 26 A cross-sectional view of the L-L part in.

[0055] Description of main element symbols:

[0056] 100 - explosion-proof valve; 110 - mounting part; 120 - explosion-proof valve body; 200 - weak part; 210 - first straight section; 220 - second straight section; 230 - curved section; 300 - buffer body; 310 - first wall surface; 320 - second wall surface; 400 - top cover plate; 410 - mounting hole; 500 - housing. Detailed implementation manners

[0057] The embodiments of the present application will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present application and should not be construed as a limitation to the present application.

[0058] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. On the contrary, when an element is referred to as being "directly on" another element, there is no intermediate element. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for the purpose of illustration.

[0059] In the present application, unless otherwise clearly specified and defined, the terms "mount", "connect", "couple", "fix" and other terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0060] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of this application, "a plurality of" means two or more unless specifically defined otherwise.

[0061] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs. The terms used in the description of the template herein are for the purpose of describing specific embodiments only and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0062] As Figures 1 to 3 shown, this application provides a battery cell, which is mainly applied to mobile devices, electric vehicles, household appliances, energy storage devices, etc., to improve the stability of the bursting value of the explosion-proof valve 100, so as to ensure the accuracy of the bursting value of the explosion-proof valve 100 in the battery cell.

[0063] The battery cell includes a housing 500, a top cover plate 400, and an explosion-proof valve 100.

[0064] Among them, the housing 500 has an open receiving cavity, that is, the interior of the housing 500 has a receiving cavity, and an opening communicating with the receiving cavity is provided on the side wall of the housing 500, and this opening is located on one side in the length direction or width direction of the housing 500.

[0065] In addition, the top cover plate 400 is connected to the housing 500 and seals the opening, so as to seal the opening through the top cover plate 400, thereby forming a sealed receiving cavity. In this embodiment, the top cover plate 400 and the housing 500 are connected by welding to improve the stability of the connection between the top cover plate 400 and the housing 500, and at the same time improve the sealing quality of the top cover plate 400 for the opening, and prevent liquid or other impurities outside the housing 500 from entering the receiving cavity through the opening.

[0066] The top cover plate 400 has a mounting hole 410 penetrating through the top cover plate 400 along the thickness direction of the top cover plate 400, and this mounting hole 410 communicates with the receiving cavity, so that the gas with too high pressure generated inside the battery cell arranged in the receiving cavity can be discharged through the mounting hole 410 to release the pressure in the receiving cavity.

[0067] Specifically, the explosion-proof valve 100 includes an explosion-proof valve body 120 and a mounting portion 110. The mounting portion 110 is circumferentially connected to the explosion-proof valve body 120. The mounting portion 110 is connected to the hole wall of the mounting hole 410, that is, the mounting portion 110 and the hole wall of the mounting hole 410 are formed by welding or integrally connected, that is, the mounting portion 110 and the hole wall of the mounting hole 410 are hermetically connected, so as to seal the mounting hole 410 through the explosion-proof valve 100 to prevent external liquid or other impurities from entering the accommodation cavity through the mounting hole 410.

[0068] It should be noted that the axis of the explosion-proof valve 100 coincides with or is parallel to the axis of the mounting hole 410, so as to avoid the explosion-proof valve 100 tilting in the mounting hole 410, to ensure the uniformity of the force on each position of the explosion-proof valve body 120, and thus ensure the stability of the explosion-proof valve 100.

[0069] Furthermore, the explosion-proof valve body 120 is provided with a weak portion 200. The shape of the weak portion 200 can be at least any one or a combination of two or more of a straight line type, a curve type, a broken line type, a letter type, a number type, a circular type, an oval type, and a polygonal type.

[0070] Among them, the weak portion 200 is used to release pressure when the internal pressure of the battery cell reaches a threshold value. Specifically, when the internal pressure of the battery cell reaches the threshold value, the weak portion 200 can rupture under the action of the pressure, so that the explosion-proof valve 100 can be opened under the action of the aforementioned pressure. That is to say, when the explosion-proof valve 100 is opened, the explosion-proof valve 100 has no sealing effect on the mounting hole 410, and the accommodation cavity is communicated with the outside of the housing 500 through the mounting hole 410, so that the gas generated inside the battery cell can be discharged through the mounting hole 410 and the pressure can be released, thereby avoiding explosion due to excessive internal pressure of the battery cell and improving the safety of the battery cell during use.

[0071] It should be noted that by providing the weak portion 200 on the explosion-proof valve body 120, that is, along the thickness direction of the explosion-proof valve body 120, the thickness of the weak portion 200 is less than the thickness of the explosion-proof valve body 120, that is, the compressive strength of the weak portion 200 is less than the compressive strength of other parts of the explosion-proof valve 100. When the internal pressure of the battery cell reaches the threshold value, the weak portion 200 can be disconnected under the action of this pressure value and form a notch on the explosion-proof valve body 120, so that the internal pressure of the battery cell can be released through this notch, thereby preventing the battery cell from exploding due to excessive pressure.

[0072] Specifically, a part of the weak part 200 of the planar structure is recessed or arched along the thickness direction of the top cover sheet 400 to form a buffer body 300. By providing the buffer body 300, the residual stress and strain generated during the welding process between the mounting part 110 of the explosion-proof valve 100 and the hole wall of the mounting hole 410 can be released, so as to enhance the deformation resistance of the weak part 200 in the explosion-proof valve 100, and avoid the weak part 200 of the explosion-proof valve 100 from being stressed and pulled or even deformed during the welding process between the explosion-proof valve 100 and the hole wall of the mounting hole 410, so as to ensure the integrity of the weak part 200 and the stability of the explosion-proof value of the explosion-proof valve 100.

[0073] In this embodiment, the weak part 200 has at least two ends. When the weak part 200 breaks under pressure, a part of the explosion-proof valve body 120 flips along the weak part 200 and forms an exhaust port on the explosion-proof valve body 120, which can effectively prevent a part of the explosion-proof valve body 120 from detaching from the explosion-proof valve body 120 under pressure.

[0074] As Figure 3 and Figure 25 shown, in some embodiments of the present application, a plurality of buffer bodies 300 are provided on the weak part 200, and the plurality of buffer bodies 300 are arranged continuously or at intervals.

[0075] It should be noted that, along the direction perpendicular to the thickness of the explosion-proof valve 100, there is a gap between the side wall of the weak part 200 and the buffer body 300. Among them, the weak part 200 refers to one side in the thickness direction of the explosion-proof valve body 120, and the weak part 200 is formed by etching on the surface of the explosion-proof valve body 120, that is, the thickness of the weak part 200 is less than the thickness of the explosion-proof valve body 120.

[0076] It can be understood that the weak part 200 has a bottom wall and side walls connected to the edge of the bottom wall. The buffer body 300 specifically refers to a part of the bottom wall of the weak part 200 that is recessed or arched along the thickness direction of the top cover sheet 400. Further, there is a gap between the buffer body 300 formed by the bottom wall of the weak part 200 being recessed or arched along the thickness direction of the top cover sheet 400 and the side wall of the weak part 200.

[0077] By providing a gap between the buffer body 300 and the side wall of the weak part 200, it is avoided that the connection between the buffer body 300 and the side wall of the weak part 200 affects the deformation resistance of the buffer body 300, so as to ensure the stability of the buffer body 300 and the deformation resistance of the weak part 200.

[0078] Specifically, as Figure 3 、 Figure 4 、 Figure 8 、 Figure 13 and Figure 17As shown, in some embodiments, a plurality of buffer bodies 300 are arranged continuously along the track direction of the weak part 200.

[0079] It should be noted that the plurality of buffer bodies 300 are arranged continuously to form an integrated buffer structure. This buffer structure is arranged along the track direction of the weak part 200, that is, the shape of the buffer structure is the same as that of the weak part 200. Since there is a gap between the side wall of the weak part 200 and the buffer body 300, that is, along the track direction of the weak part 200, the length of the buffer structure is less than the length of the weak part 200, and the width of the buffer structure is less than the width of the weak part 200.

[0080] By arranging the weak part 200 continuously along the track direction of the buffer body 300, along the track direction of the weak part 200, the buffer body 300 can provide buffering and releasing effects on the stress and strain received by the weak part 200, improve the anti-deformation ability of the weak part 200, and ensure the uniformity of the anti-deformation ability of each part of the weak part 200 along the track direction of the weak part 200.

[0081] As Figures 25 to 28 shown, in some embodiments, a plurality of buffer bodies 300 are arranged at equal intervals along the track direction of the weak part 200.

[0082] Among them, the distance between two adjacent buffer bodies 300 can be specifically set according to the actual situation, and the number of buffer bodies 300 can be specifically set according to the actual situation. It should be noted that the plurality of buffer bodies 300 are arranged along the track direction of the weak part 200, and buffer bodies 300 are provided at both ends close to the track direction of the weak part 200, that is, the plurality of buffer bodies 300 are evenly distributed along the track of the weak part 200, so as to ensure the uniformity of the anti-deformation ability of any two adjacent buffer bodies 300 along the track of the weak part 200 and avoid the situation of uneven local stress.

[0083] As Figures 25 to 28 shown, in some embodiments, the buffer body 300 includes an inner wall surface (not shown in the figure) and an outer wall surface (not shown in the figure) that are oppositely arranged along the thickness direction of the top cover sheet 400, and both the inner wall surface and the outer wall surface are set as semi-spherical surfaces.

[0084] In addition, by setting both the inner wall surface and the outer wall surface of the buffer body 300 as semi-spherical surfaces, the semi-spherical structure of the buffer body 300 can be obtained, so that it can buffer evenly in all directions, so that the buffer body 300 can better buffer and release the stress and strain generated during the connection process between the explosion-proof valve 100 and the hole wall of the mounting hole 410, and ensure the anti-deformation ability of the buffer body 300 and the weak part 200.

[0085] Based on any of the above embodiments, as Figure 4 , Figure 9 and Figure 13As shown, in some embodiments of the present application, the weak part 200 has a central line area in the track width direction of the weak part 200, and a plurality of buffer bodies 300 are all arranged in the central line area.

[0086] It can be understood that in the width direction of the weak part 200, by arranging the buffer body 300 in the central line area of the weak part 200, the uniformity of the stress and strain buffering of the explosion-proof valve body 120 by the buffer body 300 is ensured, and the stability of the anti-deformation ability of the explosion-proof valve 100 is improved.

[0087] As Figure 7 and Figure 24 shown, in some embodiments of the present application, along the thickness direction of the explosion-proof valve 100, the weak part 200 includes a first wall surface 310 and a second wall surface 320 which are oppositely arranged, and the buffer body 300 is formed by a local depression of the first wall surface 310.

[0088] It should be noted that while the first wall surface 310 is locally depressed, the second wall surface 320 is locally arched synchronously, that is, the first wall surface 310 and the second wall surface always remain parallel to each other, so that the thickness of the buffer body 300 is equal to the thickness of the weak part 200, thereby the stress and strain generated during the welding process between the explosion-proof valve 100 and the hole wall of the mounting hole 410 can be released through the buffer body 300, and the anti-deformation ability of the explosion-proof valve 100 is ensured.

[0089] In addition, in some embodiments of the present application, the buffer body 300 is formed by a local arching of the first wall surface 310. It can be understood that while the first wall surface 310 is locally arched, the second wall surface 320 is locally depressed, so that the first wall surface 310 and the second wall surface always remain parallel to each other, thereby ensuring the anti-deformation ability of the explosion-proof valve 100.

[0090] As Figure 7 and Figure 24 shown, in some embodiments of the present application, along the thickness direction of the top cover sheet 400, the thickness of the mounting part 110 is greater than the thickness of the explosion-proof valve body 120, so that the connecting force between the explosion-proof valve body 120 and the mounting part 110 is less than the connecting force between the mounting part 110 and the hole wall of the mounting hole 410.

[0091] That is to say, when the battery cell arranged in the accommodation cavity is abused and the gas generated inside it reaches a certain threshold, since the thickness of the weak part 200 is thinner than the thickness of the explosion-proof valve body 120, the weak part 200 cracks, and a part of the explosion-proof valve body 120 flips along the weak part 200, thereby realizing the function of opening the valve to relieve pressure.

[0092] As Figures 16 to 19As shown, in some embodiments of the present application, the weak part 200 includes a first straight segment 210 and a second straight segment 220. The first straight segment 210 and the second straight segment 220 intersect to form an intersection point, which is located at the centroid position of the explosion-proof valve body 120.

[0093] It should be noted that the included angle between the first straight segment 210 and the second straight segment 220 can be specifically set according to the actual situation.

[0094] In this embodiment, the first straight segment 210 is arranged along the length direction of the explosion-proof valve body 120, that is, the length direction of the first straight segment 210 is parallel to the length direction of the explosion-proof valve body 120, and the second straight segment 220 is arranged along the width direction of the explosion-proof valve 100, that is, the length direction of the second straight segment 220 is parallel to the width direction of the explosion-proof valve body 120.

[0095] It can be understood that the first straight segment 210 and the second straight segment 220 are perpendicular, and the intersection point between the first straight segment 210 and the second straight segment 220 coincides with the midpoint of the first straight segment 210 and the midpoint of the second straight segment 220, so as to ensure the uniformity of the cracking force at both ends of the first straight segment 210 and both ends of the second straight segment 220 during the cracking process of the weak part 200 when the weak part 200 is cracked by an external force, and improve the weak part 200. That is to say, in this embodiment, the shape of the weak part 200 is a "cross" shape, that is, when the weak part 200 cracks under the action of pressure, the weak part 200 first cracks at the intersection point between the first straight segment 210 and the second straight segment 220, and then cracks along the directions of the first straight segment 210 and the second straight segment 220 in sequence to form an exhaust port, so that the gas in the accommodation cavity can be discharged through the exhaust port, thereby realizing pressure relief.

[0096] As Figures 8 to 11 shown, in some embodiments of the present application, the first straight segment 210 is arranged in the middle of the explosion-proof valve body, and two symmetric curve segments 230 are provided at both ends of the first straight segment 210 to form the weak part 200.

[0097] It should be noted that the structure of the curve segment 230 is the same as that of the weak part 200, that is, the curve segment 230 also has a buffer body 300.

[0098] Specifically, the first straight segment 210 is arranged along the length direction of the explosion-proof valve body 120, that is, the length direction of the first straight segment 210 is parallel to the length direction of the explosion-proof valve body 120. Along the width direction of the explosion-proof valve body 120, the first straight segment 210 is arranged at the midline of the width direction of the explosion-proof valve body 120.

[0099] In addition, at one end of the first straight line segment 210, there are two curved line segments 230 symmetric with respect to the first straight line segment 210, and at the other end of the first straight line segment 210, there are two curved line segments 230 symmetric with respect to the first straight line segment 210. The curved line segment 230 is of an arc or semi-circular structure, and the convex surface of the curved line segment 230 faces the extending direction of the first straight line segment 210. The curved line segments 230 provided at both ends of the first straight line segment 210 are centrosymmetric with respect to the midpoint of the first straight line segment 210.

[0100] As Figures 12 to 15 shown, in some embodiments of the present application, both ends of the curved line segment 230 are respectively connected to a first straight line segment 210 and a second straight line segment 220. The first straight line segment 210 and the second straight line segment 220 are parallel to each other to form a U-shaped notch segment. There are two groups of U-shaped notch segments, and the open ends of the two groups of U-shaped notch segments are arranged in opposite directions at both ends in the length direction of the explosion-proof valve body 120, and the curved line segment 230 portions of the two groups of U-shaped notch segments are connected to form a weak part 200.

[0101] It should be noted that the two groups of U-shaped notch segments are symmetric with respect to the bisector in the width direction of the explosion-proof valve body 120, that is, the open ends of the two groups of U-shaped notch segments face the length direction of the explosion-proof valve body 120.

[0102] Furthermore, the length of the first straight line segment 210 is equal to the length of the second straight line segment 220, and the length directions of the first straight line segment 210 and the second straight line segment 220 are parallel to the length direction of the explosion-proof valve body 120.

[0103] As Figures 3 to 6 、 Figures 20 to 23 shown, in some embodiments of the present application, the curved line segments 230 of the two groups of U-shaped notch segments are respectively arranged at both ends of the explosion-proof valve body. The open ends of the two groups of U-shaped notch segments are arranged facing each other, and one end of the two groups of U-shaped notch segments is connected by the first straight line segment 210 to form a weak part 200.

[0104] Specifically, the opposite ends of the two groups of U-shaped notch segments are connected by the first straight line segment 210, and the opposite ends of the two groups of U-shaped notch segments are spaced apart from each other. The first straight line segment 210 is parallel to the second straight line segment 220, and the weak part 200 provided in this embodiment is symmetric with respect to the bisector in the width direction of the explosion-proof valve body 120 to ensure the uniformity and consistency of the forces on the two groups of U-shaped notch segments. That is to say, when the two groups of U-shaped notch segments are subjected to the gas pressure in the accommodation cavity, they can crack synchronously when the pressure reaches the threshold value.

[0105] Some embodiments of the present application provide a battery pack, which includes the battery cells described in any one of the above embodiments.

[0106] Among them, the battery pack has the structure and beneficial effects of the battery cells described in any of the above embodiments, which will not be elaborated here one by one.

[0107] Some embodiments of the present application provide an electrical device, which includes the battery pack described in any of the above embodiments.

[0108] Among them, the electrical device has the structure and beneficial effects of the battery pack described in the above embodiments, which will not be elaborated here one by one.

[0109] In all the examples shown and described here, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values.

[0110] It should be noted that: like reference numerals and letters denote like items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0111] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application.

Claims

1. A battery cell, characterized in that: include: A housing (500), the housing having an open accommodating cavity; A top cover sheet (400), the top cover sheet (400) being connected to the housing (500) and covering the opening, the top cover sheet (400) having a mounting hole (410) penetrating the top cover sheet (400) along a thickness direction of the top cover sheet (400); An explosion-proof valve comprises an explosion-proof valve body (120) and a mounting portion (110); The mounting portion (110) is circumferentially connected to the explosion-proof valve body (120), and the mounting portion (110) is connected to the hole wall of the mounting hole; The explosion-proof valve body (120) is provided with a weak portion (200), and the weak portion (200) is used to rupture when the internal pressure of the battery cell reaches a threshold value to release the pressure; The weak portion (200) is partially recessed or arched along the thickness direction of the top cover sheet (400) to form a buffer body (300).

2. The battery cell according to claim 1, characterized in that: A plurality of the buffer bodies (300) are arranged on the weak portion (200), and the plurality of the buffer bodies (300) are arranged at intervals.

3. The battery cell according to claim 2, characterized in that: The weak portion (200) has a midline region located in the width direction of the track of the weak portion (200), and the plurality of buffer bodies (300) are all arranged in the midline region.

4. The battery cell according to claim 1, characterized in that: The weak portion (200) comprises a first wall surface (310) and a second wall surface (320) which are arranged opposite to each other, and the buffer body (300) is formed by a local depression or arch of the first wall surface (310).

5. The battery cell according to claim 4, characterized in that: The buffer body (300) comprises an inner wall surface and an outer wall surface which are arranged opposite to each other, and both the inner wall surface and the outer wall surface are semi-spherical surfaces.

6. The battery cell according to claim 2, characterized in that: Along the trajectory direction of the weak portion (200), a plurality of buffer bodies (300) are arranged at equal distances.

7. The battery cell according to claim 1, characterized in that: Along the thickness direction of the top cover sheet (400), the thickness of the mounting portion (110) is greater than the thickness of the explosion-proof valve body (120).

8. The battery cell according to claim 1, characterized in that: The weak portion (200) comprises a first straight line segment (210) and a second straight line segment (220); The first straight line segment (210) and the second straight line segment (220) intersect to form an intersection, and the intersection is located at the centroid of the explosion-proof valve body (120).

9. The battery cell according to claim 1, characterized in that: The weak portion (200) comprises a first curved segment and a second curved segment; The first curved segment and the second curved segment are axially symmetrically arranged with respect to a midline in a width direction of the explosion-proof valve body (120), and / or the first curved segment and the second curved segment are axially symmetrically arranged with respect to a midline in a length direction of the explosion-proof valve body (120).

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

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