Battery cell, battery and electrical device

Abstract

A battery cell (100), a battery (200) and an electric device (1000). The battery cell (100) comprises a housing (10), a shielding member (20) and a pressing member (30), wherein the housing (10) has a first wall (11), the first wall (11) being provided with a weak portion (110); the shielding member (20) is arranged in the housing (10), and in the direction of thickness h of the first wall (11), the shielding member (20) covers at least part of the weak portion (110); and the pressing member (30) is located on the side of the shielding member (20) that faces away from the first wall (11), the pressing member (30) pressing against the shielding member (20).

Description

Battery cells, batteries and electrical equipment

[0001] Priority information

[0002] This application claims priority and benefits of patent application No. 202323260109.2 filed with the State Intellectual Property Office of China on November 29, 2023, and the entire text of which is incorporated herein by reference. Technical Field

[0003] The present application relates to the field of battery technology, and in particular to a battery cell, a battery, and an electrical device. Background Art

[0004] The bottom of a battery cell has a weak point, such as an explosion-proof valve. The electrolyte within the cell may come into contact with the valve for extended periods, and the flow of electrolyte can impact the valve, potentially causing it to open prematurely. To reduce the impact of electrolyte on the valve, related art incorporates a shielding member within the battery cell to cover the valve. However, this shielding member can easily drift to other locations as the electrolyte flows, rendering it unable to continuously cover the valve.

[0005] Summary of the Invention

[0006] The present application provides a battery cell, a battery, and an electrical device, in which a shielding member is easily displaced to other locations along with the flow of electrolyte, and thus cannot continuously cover a weak portion.

[0007] The battery cell of the embodiment of the present application includes:

[0008] a housing having a first wall, wherein the first wall is provided with a weakened portion;

[0009] a shielding member disposed in the housing, the shielding member covering at least a portion of the weak portion along a thickness direction of the first wall; and

[0010] A pressing member is located at a side of the shielding member facing away from the first wall, and presses the shielding member.

[0011] In the battery cell of the embodiment of the present application, the weak portion can open when the pressure within the housing reaches a certain value, thereby reducing the pressure within the housing and reducing the probability of structural damage to the battery cell. The shielding member can reduce the impact of the electrolyte on at least part of the weak portion in the thickness direction of the first wall, thereby reducing to a certain extent the probability of the weak portion opening prematurely due to the impact of the electrolyte. The pressure member can apply a certain force to the shielding member, thereby limiting the position of the shielding member and reducing the probability of the shielding member moving to other positions due to the flow of electrolyte, so that the shielding member can continuously cover the weak portion.

[0012] In some embodiments, the first wall has a first groove and a second groove, the first groove extends from the outer surface of the first wall along the thickness direction of the first wall to the inner surface of the first wall, the second groove passes through the bottom surface of the first groove and the inner surface of the first wall, and the weak portion is arranged in the first groove.

[0013] In this way, the arrangement of the first groove and the second groove is conducive to thinning the first wall. The weak portion is arranged in the first groove, so that the weak portion can be opened in time when the pressure in the shell reaches a certain value, thereby improving the functional stability of the weak portion.

[0014] In some embodiments, the pressing member includes a plate body and a protrusion provided on the plate body, the protrusion presses the shielding member, and the protrusion is used to form a fluid channel.

[0015] In this way, the protrusion can press against the shielding member, reducing the probability of the shielding member moving to other locations with the flow of electrolyte, allowing the shielding member to continuously cover the weak portion. The fluid channel allows some electrolyte to flow between the shielding member and the pressing member. When the pressure in the housing reaches a certain value, the electrolyte can impact the shielding member and further impact the weak portion, causing the weak portion to open.

[0016] In some embodiments, there are multiple protrusions, and the multiple protrusions are arranged along the width direction of the pressing member. At least one protrusion presses the shielding member, and the fluid channel is formed between the multiple protrusions.

[0017] In this way, the multiple protrusions can increase the contact area between the pressure member and the shielding member, allowing the pressure member to effectively press the shielding member. The fluid channels formed between the multiple protrusions allow part of the electrolyte to flow along a predetermined flow path, thereby more precisely controlling the electrolyte flow behavior. When the pressure within the housing reaches a certain value, the electrolyte flows along the predetermined flow path to impact the shielding member and further impact the weak portion, causing the weak portion to open.

[0018] In some embodiments, the plurality of protrusions press against the shielding member, and the area of ​​each protrusion pressing against the shielding member is equal.

[0019] In this way, the area of ​​each protrusion pressing against the shielding member is equal, which ensures that the pressure on the shielding member is evenly distributed and does not cause uneven pressure due to a protrusion being too large or too small. This helps to improve the stability of the shielding member and helps to evenly distribute the electrolyte around the weak part.

[0020] In some embodiments, the width of the weak portion is W1, and the farthest distance between the plurality of protrusions along the width direction of the pressing member is W2, and W1 and W2 satisfy: W2 ≥ W1 + 4, in mm.

[0021] In this way, the area where the protrusion presses the shielding member can be distributed outside the weak portion, so that the shielding member can be effectively pressed.

[0022] In some embodiments, along the width direction of the pressing member, the farthest distance between the plurality of protrusions is W2, the width of the shielding member is W3, and W2 and W3 satisfy: 0≤|W3-W2|≤10, in mm.

[0023] In this way, the width of the shielding member is close to the area that the protrusion can press, and the edge of the shielding member can be effectively pressed.

[0024] In some embodiments, the shielding member includes a first surface and a second surface facing each other, the protrusion presses against the first surface, the contact area between the first surface and the protrusion is S1, and the area of ​​the first surface is S2, where S1 and S2 satisfy:

[0025] 20%≤S1 / S2≤80%.

[0026] Thus, within this range, the protrusion can effectively press against the first surface, thereby stably limiting the position of the shielding member and reducing the probability of the shielding member moving to other locations due to the flow of electrolyte, allowing the shielding member to continuously cover the weak portion. Furthermore, the electrolyte can flow in the area where the protrusion and the first surface do not contact each other. When the pressure within the housing reaches a certain value, the electrolyte can impact the shielding member and further impact the weak portion, causing the weak portion to open.

[0027] In some embodiments, along the thickness direction of the first wall, the projection of the pressing member completely covers the projection of the shielding member.

[0028] In this way, along the thickness direction of the first wall, the projection of the pressure member completely covers the projection of the shielding member, which makes the shielding member always within the coverage range of the pressure member, so that the pressure member can effectively reduce the impact of the electrolyte on the shielding member, thereby reducing the probability of the shielding member floating to other positions with the flow of the electrolyte, so that the shielding member can continuously cover the weak part.

[0029] In some embodiments, the shielding member has a contact area that contacts the pressing member, and the contact area is spaced apart from the weak portion along a direction perpendicular to the thickness of the first wall.

[0030] In this way, the contact area is spaced from the weak portion in a direction perpendicular to the thickness of the first wall, which can reduce the probability of the pressing member contacting the weak portion, thereby reducing the probability of the pressing member applying pressure to the weak portion, and further reducing the probability of the weak portion opening prematurely under the pressure of the pressing member.

[0031] In some embodiments, the covering member includes a first part, a second part and a bonding structure arranged on the second part, the first part is connected to the second part, the first part covers at least part of the weak part along the thickness direction of the first wall, the second part is bonded to the first wall through the bonding structure, and the pressing member presses the second part.

[0032] In this way, the first portion covers at least a portion of the weak portion along the thickness direction of the first wall, providing protection for the weak portion. The second portion is bonded to the first wall via the adhesive structure, enabling the shielding member to form a relatively stable connection with the first wall. The pressing member presses against the second portion, further enhancing the stability of the connection between the shielding member and the first wall.

[0033] In certain embodiments, the bonding structure protrudes from the surface of the second portion, and the bonding structure and the first portion together form a gas channel, and the gas channel extends to the edge of the shielding member.

[0034] This allows gas inside the housing to flow through the gas channel to the weak part, allowing the weak part to open when the pressure inside the housing reaches a certain value, improving the functional stability of the weak part. Furthermore, the provision of the gas channel facilitates the detection of the welding condition of the weak part.

[0035] In some embodiments, the pressing member includes a width edge, and along the length direction of the shielding member, the bonding structure includes a first edge and a second edge opposite to the first edge, the first edge is close to the width edge relative to the second edge, the distance between the first edge and the second edge is A1, and the distance between the first edge and the width edge is A2, and A1 and A2 satisfy: 10%≤A1 / A2≤80%.

[0036] In this way, the pressing member can effectively press the shielding member, and further press the area where the bonding structure bonds the shielding member and the first wall, thereby improving the connection strength between the shielding member and the first wall.

[0037] In some embodiments, the battery cell includes an electrode assembly, an insulating film and a connecting piece, the insulating film wraps the electrode assembly and is located on the side of the pressing member facing away from the first wall, one end of the connecting piece is connected to the insulating film, the protrusion presses against the other end of the connecting piece, and the thickness of the shielding member is less than or equal to the thickness of the connecting piece.

[0038] In this way, the insulating film can reduce the probability of contact between the electrode assembly and the outer casing, thereby reducing the probability of the electrode assembly short-circuiting and improving the reliability of the battery cell. The connecting piece can fix the insulating film, improving the stability of the insulating film wrapped around the electrode assembly, and can connect the insulating film and the pressure member, reducing the probability of the pressure member moving with the flow of electrolyte. The thickness of the shielding member is less than or equal to the thickness of the connecting piece, which can reduce the space occupied by the shielding member in the thickness direction of the first wall and improve the utilization rate of the internal space of the outer casing.

[0039] In certain embodiments, the housing includes a shell and an end cover plate, the shell is formed with an opening, the end cover plate covers the opening of the shell, and the first wall is located on the shell.

[0040] In this way, the end cover can separate the internal environment of the shell from the external environment, avoiding the adverse effects of the external environment on the internal environment. The first wall is located on the shell, so that the weak part has a larger design space, thereby improving the pressure relief effect of the weak part.

[0041] The battery according to the embodiment of the present application includes the battery cell described in any of the above embodiments.

[0042] Since the battery includes the above-mentioned battery cell, it at least includes all the beneficial effects of the above-mentioned battery cell, which will not be described in detail here.

[0043] The electrical equipment of the embodiment of the present application includes the battery described in the above embodiment or the battery cell described in any of the above embodiments.

[0044] Since the electrical equipment includes the above-mentioned battery or battery cell, it at least includes all the beneficial effects of the above-mentioned battery or battery cell, which will not be described in detail here.

[0045] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0047] FIG1 is a schematic diagram of the structure of an electrical device provided in some embodiments of the present application;

[0048] FIG2 is a schematic structural diagram of a battery provided in some embodiments of the present application;

[0049] FIG3 is a disassembled diagram of a battery cell provided in some embodiments of the present application;

[0050] FIG4 is a partial schematic diagram of a battery cell provided in some embodiments of the present application;

[0051] FIG5 is a schematic structural diagram of a first wall and a weak portion provided in some embodiments of the present application;

[0052] FIG6 is a cross-sectional view of a first wall, a shielding member, and a pressing member provided in some embodiments of the present application;

[0053] FIG7 is an enlarged view of a portion of the cross-sectional view of the first wall, the shielding member, and the pressing member in FIG6 ;

[0054] FIG8 is a disassembled schematic diagram of a pressing member, a shielding member, and a weak portion provided in some embodiments of the present application;

[0055] FIG9 is a schematic diagram showing the positional relationship among a pressing member, a shielding member, and a weak portion provided in some embodiments of the present application;

[0056] FIG10 is a schematic structural diagram of a shielding member provided in some embodiments of the present application;

[0057] FIG11 is a schematic diagram of the projection relationship between the pressing member and the shielding member provided in some embodiments of the present application;

[0058] FIG12 is a schematic diagram showing the positional relationship among a pressing member, a shielding member, and a weak portion provided in some embodiments of the present application;

[0059] FIG13 is a schematic diagram showing the positional relationship between a shielding member and a weak portion provided in some embodiments of the present application;

[0060] FIG14 is an enlarged view of part b of the cross-sectional view of the first wall, the shielding member, and the pressing member in FIG6 .

[0061] Description of reference numerals:

[0062] Battery cell 100; outer shell 10; first wall 11; weak portion 110; shielding member 20; pressing member 30; opening 31; first groove 111; second groove 112; gas channel 113; plate body 32; protrusion 33; fluid channel 101; first surface 21; second surface 22; contact area 23; first portion 24; second portion 25; adhesive structure 26; width edge 34; first edge 260; second edge 261; first sub-portion 250; second sub-portion 251; electrode assembly 40; insulating film 50; connecting piece 60; pole 70; adapter piece 80; shell 12; opening 120; end cover plate 13; battery 200; electrical device 1000; controller 300; motor 400; battery case 500. DETAILED DESCRIPTION

[0063] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0064] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0065] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0066] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0067] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0068] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0069] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0070] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0071] Currently, market developments indicate that batteries are increasingly being used. They are not only used in energy storage systems such as hydropower, thermal, wind, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric cars, as well as in aerospace and other fields. As battery applications continue to expand, market demand is also growing.

[0072] During the use of a battery cell, if a short circuit, overcurrent, or external impact occurs, the chemical reaction inside the cell will generate a large amount of heat and gas, causing the internal pressure of the cell to increase. If the pressure cannot be effectively released, it will cause structural damage to the battery cell and even cause an explosion.

[0073] A weak point can be provided at the bottom of the battery cell. This weak point can be formed by thinning the material at the bottom of the battery cell. This weak point can be an explosion-proof valve. The explosion-proof valve can sense pressure changes inside the battery. When the pressure reaches a certain value, the explosion-proof valve will open a channel to discharge high-pressure gas and liquid, thereby reducing the pressure inside the battery and reducing the probability of structural damage to the battery cell.

[0074] However, the electrolyte within the battery cells is often in motion. This electrolyte may be in contact with the explosion-proof valve for extended periods, potentially impacting the valve. Furthermore, if the electrolyte flows too quickly, it exerts a greater impact force on the valve, potentially causing it to open prematurely and ultimately malfunction.

[0075] To address the issue of explosion-proof valve malfunction, a shielding member can be placed over the explosion-proof valve to cover the valve. However, the shielding member may migrate with the electrolyte to other locations within the battery cell, rendering it unable to cover the explosion-proof valve. In view of this, the present application provides a battery cell in which pressure is applied to the shielding member to prevent it from migrating with the electrolyte to other locations within the battery cell, thereby reducing the probability of explosion-proof valve malfunction and improving the stability of the battery cell.

[0076] The electrical equipment of the embodiments of the present application includes a battery cell or battery in any of the following embodiments. Specifically, the electrical equipment may use a battery or battery cell as a power source, and the electrical equipment may include, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc.

[0077] Among them, electric toys may include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys and electric airplane toys, etc., and spacecraft may include airplanes, rockets, space shuttles and spacecraft, etc.

[0078] For the convenience of explanation, the following embodiments are described by taking a vehicle as an example of an electrical device in accordance with an embodiment of the present application.

[0079] Please refer to Figure 1, which is a schematic diagram of the structure of an electric device 1000 provided in some embodiments of the present application. A battery 200 is installed inside the vehicle. Battery 200 can be located at the bottom, front, or rear of the vehicle. Battery 200 can be used to power the vehicle, for example, as the vehicle's operating power source.

[0080] The vehicle may further include a controller 300 and a motor 400 . The controller 300 is used to control the battery 200 to supply power to the motor 400 , for example, to meet the vehicle's power requirements for starting, navigating, and driving.

[0081] In the embodiment of the present application, the battery 200 can not only serve as the operating power source of the vehicle, but also serve as the driving power source of the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0082] Please refer to Figure 2, which is a schematic diagram of the structure of a battery 200 provided in some embodiments of the present application. The battery 200 of the embodiment of the present application includes a plurality of battery cells 100 of any of the following embodiments.

[0083] In the embodiments of the present application, the battery cell 100 may include a lithium-ion secondary battery, a lithium-ion primary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery, or a magnesium-ion battery, etc., and the embodiments of the present application are not limited to this. The battery cell 100 may be cylindrical, flat, rectangular, or other shapes, and the embodiments of the present application are not limited to this. The battery cell 100 is generally divided into three types according to the packaging method: cylindrical battery cells, prismatic battery cells, and soft-pack battery cells, and the embodiments of the present application are not limited to this.

[0084] The battery 200 typically includes a battery case 500 that encloses one or more battery cells 100. Multiple battery cells 100 can be housed within the battery case 500, which prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells 100. As a carrier for the battery cells 100, the battery case 500 plays a critical role in their reliability. The battery case 500 must meet strength and stiffness requirements, as well as the IP65 protection level required for electrical equipment enclosures, while also providing collision protection.

[0085] The shape of the battery box 500 can be a cuboid, a cube, etc. The battery box 500 can be cast from materials such as steel plates and aluminum alloys; or new lightweight materials such as glass fiber reinforced composite materials and carbon fiber reinforced composite materials can be used.

[0086] In some embodiments, the battery 200 may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0087] Please refer to FIG3 , which is a disassembled view of a battery cell 100 provided in some embodiments of the present application. In certain embodiments, the battery cell 100 includes a housing 12 and an electrode assembly 40 , wherein the electrode assembly 40 is disposed in the housing 12 .

[0088] The electrode assembly 40 is a component where electrochemical reactions occur in the battery cell 100. One or more electrode assemblies 40 may be contained within the housing 12 of the battery cell 100.

[0089] Please refer to Figures 4, 5, 6 and 7. Figure 4 is a partial schematic diagram of the battery cell 100 provided in some embodiments of the present application; Figure 5 is a structural schematic diagram of the first wall 11 and the weak portion 110 provided in some embodiments of the present application; Figure 6 is a cross-sectional view of the first wall 11, the shielding member 20 and the pressure member 30 provided in some embodiments of the present application; Figure 7 is an enlarged view of part a of the cross-sectional view of the first wall 11, the shielding member 20 and the pressure member 30 in Figure 6.

[0090] The battery cell 100 according to the embodiment of the present application includes a housing 10, a shielding member 20, and a pressing member 30. The housing 10 has a first wall 11 with a weakened portion 110. The shielding member 20 is disposed within the housing 10 and covers at least a portion of the weakened portion 110 along the thickness direction h of the first wall 11. The pressing member 30 is located on the side of the shielding member 20 facing away from the first wall 11 and presses against the shielding member 20.

[0091] Specifically, the outer shell 10 forms the outer contour of the battery cell 100. The interior of the outer shell 10 can be used to accommodate various components of the battery cell 100. The outer shell 10 can include multiple walls of a certain thickness. The first wall 11 is any wall of the outer shell 10, which can be a top wall, a bottom wall, or a side wall.

[0092] The first wall 11 is provided with a weakened portion 110, which is designed to rupture and release pressure from the battery cell 100 when the temperature or pressure inside the housing 10 exceeds a threshold. The weakened portion 110 can be formed by thinning the material, for example, by scoring or slotting the first wall 11. The thickness of the first wall 11 is greater around the weakened portion than at the thinned portion.

[0093] In some embodiments, the weak portion 110 includes a notch, which may be linear, and the shielding member 20 may shield part or all of the weak portion 110. When the internal temperature or pressure of the battery cell 100 exceeds a threshold, the weak portion 110 tears open at the notch, thereby releasing pressure.

[0094] In some embodiments, the thinned portion may also be an explosion-proof valve mounted on the housing 10. The explosion-proof valve may be in a closed annular shape, such as a circular annular shape, a rectangular annular shape, etc., and the inner area surrounded by the explosion-proof valve and the annular area where the explosion-proof valve itself is located form a pressure relief zone, or the inner area surrounded by the explosion-proof valve, the area where the explosion-proof valve itself is located, and an area within a certain range outside the explosion-proof valve form a pressure relief zone.

[0095] When the internal temperature or pressure of the housing 10 exceeds a threshold, the explosion-proof valve is partially or completely torn, causing the pressure relief area to flip up relative to other areas of the first wall 11 or separate from the first wall 11 to achieve faster pressure relief.

[0096] The explosion-proof valve can also be a non-closed ring, such as a C-shaped ring structure. The area surrounded by the ring or quasi-ring corresponding to the C-shaped ring structure, or the area within a certain range outside the ring or quasi-ring forms a pressure relief zone.

[0097] When the internal temperature or pressure of the housing 10 exceeds a threshold value, the explosion-proof valve is partially or completely torn, so that the pressure relief area is turned up relative to other areas of the first wall 11 to achieve faster pressure relief.

[0098] The shielding member 20 can be made of an insulating material. For example, the shielding member 20 may include a portion made of PET (Polyethylene terephthalate). Along the thickness direction h of the first wall 11, the shielding member 20 covers at least a portion of the weak portion 110. Covering means that the shielding member 20 covers the surface of the weak portion 110, or the shielding member 20 is spaced apart from the weak portion 110, but the orthographic projection of the shielding member 20 on the first wall 11 covers the weak portion 110.

[0099] In some embodiments, the shielding member 20 is connected to the inner wall of the housing 10 . For example, the shielding member 20 may be connected to the first wall 11 of the housing 10 , or may be connected to other inner walls.

[0100] In some embodiments, the shielding member 20 is connected to the first wall 11 of the outer shell 10. Since the weak portion 110 is provided on the first wall 11 and the shielding member 20 is also connected to the first wall 11, the shielding member 20 occupies a smaller space in the outer shell 10 while satisfying the requirement of covering the weak portion 110.

[0101] Furthermore, since the shielding member 20 is arranged in the outer shell 10, the shielding member 20 covers the inner side of the weak portion 110, that is, the shielding member 20 separates the weak portion 110 covered by it from the electrolyte, which can prevent the electrolyte from directly contacting the weak portion 110, thereby protecting the weak portion 110 to a certain extent.

[0102] The pressing member 30 is used to apply pressure to stabilize the position of the shielding member 20 so that the shielding member 20 can effectively cover the weak portion 110. The pressing member 30 can be a bottom support plate of the battery cell 100. Since the bottom support plate is a structural component located at the bottom of the battery cell 100 housing 10, there is no need to add additional parts to the housing 10, thereby avoiding the additional space occupied by the installation of the pressing member 30.

[0103] The bottom support plate supports the electrode assembly 40 of the battery cell 100 and helps maintain the structural integrity of the electrode assembly 40. In this way, the pressure exerted by the bottom support plate on the shielding member 20 is at least the sum of the weight of the bottom support plate and the electrode assembly 40, thereby more effectively stabilizing the position of the shielding member 20.

[0104] Of course, the pressing member 30 can also be a component manufactured independently. After manufacturing, the pressing member 30 is placed on the side of the shielding member 20 away from the first wall 11, and the pressing member 30 presses the shielding member 20 to limit the position of the shielding member 20.

[0105] Please refer to Figure 8, which is a disassembled schematic diagram of the pressing member 30, the shielding member 20, and the weakened portion 110 provided in some embodiments of the present application. In some embodiments, the pressing member 30 may be provided with a plurality of openings 31, which may be through-holes extending through the pressing member 30 along its thickness. The thickness direction of the pressing member 30 may be the same as the thickness direction h of the first wall 11.

[0106] After the pressing member 30 presses against the shielding member 20, a small gap may exist between the shielding member 20 and the pressing member 30. Due to this small gap, the electrolyte may have difficulty contacting the shielding member 20. This can result in the electrolyte impacting the pressing member 30 rather than the shielding member 20 when the pressure inside the housing 10 exceeds a threshold. The electrolyte may not be able to impact the weak portion 110, and the weak portion 110 may not open, causing the weak portion 110 to malfunction, i.e., the pressure relief function to fail. The provision of the opening 31 facilitates partial electrolyte contact with the shielding member 20, reducing the probability of functional failure of the weak portion 110.

[0107] In the battery cell 100 of the embodiment of the present application, the weak portion 110 can open when the pressure within the outer shell 10 reaches a certain value, thereby reducing the pressure within the outer shell 10 and reducing the probability of structural damage to the battery cell 100. The shielding member 20 can reduce the impact of the electrolyte on at least a portion of the weak portion 110 in the thickness direction h of the first wall 11, thereby reducing the probability of the weak portion 110 opening prematurely due to the impact of the electrolyte. The pressure member 30 can apply a certain force to the shielding member 20, thereby limiting the position of the shielding member 20 and reducing the probability of the shielding member 20 being freed to other positions due to the flow of electrolyte, so that the shielding member 20 can continuously cover the weak portion 110.

[0108] Please refer to Figures 6 and 7. In some embodiments, the first wall 11 has a first groove 111 and a second groove 112. The first groove 111 extends from the outer surface of the first wall 11 along the thickness direction h of the first wall 11 to the inner surface of the first wall 11. The second groove 112 passes through the bottom surface of the first groove 111 and the inner surface of the first wall 11. The weak portion 110 is arranged in the first groove 111.

[0109] Specifically, the first groove 111 and the second groove 112 can be formed by removing part of the material on the first wall 11. The bottom wall of the first groove 111 can be provided with the first groove 111, and the bottom wall of the first groove 111 can be provided with a notch to form the weak portion 110. The provision of the first groove 111 reduces the thickness of the area of ​​the first wall 11 provided with the weak portion 110, so as to facilitate pressure relief through the weak portion 110.

[0110] In this way, the setting of the first groove 111 and the second groove 112 is conducive to thinning the first wall 11. The weak portion 110 is set in the first groove 111, so that the weak portion 110 can be opened in time when the pressure in the shell 10 reaches a certain value, thereby improving the functional stability of the weak portion 110.

[0111] In some embodiments, a through hole is provided through the first wall 11. The weak portion 110 may be an explosion-proof valve disc, which may be installed in the through hole and welded to the first wall 11. The explosion-proof valve disc may be provided with notches to enable the valve disc to open promptly when the pressure within the housing 10 reaches a certain value, thereby improving the functional stability of the explosion-proof valve disc.

[0112] Referring to FIG. 7 and FIG. 8 , in some embodiments, the pressing member 30 includes a plate body 32 and a protrusion 33 disposed on the plate body 32 . The protrusion 33 presses against the shielding member 20 , and the protrusion 33 is used to form a fluid channel 101 .

[0113] Specifically, the plate body 32 can be a plate of regular shape, such as a square plate, or a plate of irregular shape. The protrusion 33 can be a protrusion or structure located on the plate body 32. The protrusion 33 can be integrally formed with the plate body 32, or the protrusion 33 can be separately formed from the plate body 32. The shape of the protrusion 33 can be a regular shape, such as a rectangular parallelepiped, or an irregular shape. The number of protrusions 33 and plate body 32 can be one-to-one corresponding, or many-to-one, that is, multiple protrusions 33 correspond to one plate body 32. The shape and number of the protrusions 33 can be designed as needed, and the embodiments of the present application do not limit this.

[0114] The fluid channel 101 may be a channel defined between protrusions 33. It is understood that the plate 32 may have multiple protrusions 33. A gap exists between the protrusions 33, and this gap serves as the fluid channel 101. The fluid channel 101 may also be a channel defined between the protrusions 33 and the inner wall of the housing 10. It is understood that a gap between the protrusions 33 and the inner wall serves as the fluid channel 101.

[0115] The fluid may be a gas or an electrolyte. The fluid channel 101 can disperse the impact force of the electrolyte, thereby reducing the probability of the shielding member 20 moving to other locations along with the flow of the electrolyte, so that the shielding member 20 can continuously cover the weak portion 110.

[0116] The fluid channel 101 can also serve as a passage for gas to pass through. When the pressure inside the housing 10 exceeds a threshold, the gas inside the housing 10 can pass through the fluid channel 101, thereby impacting the shielding member 20 and further impacting the weak portion 110 to achieve a pressure relief function.

[0117] In this way, the protrusion 33 can press against the shielding member 20, reducing the probability of the shielding member 20 being displaced by the electrolyte flow, allowing the shielding member 20 to continuously cover the weak portion 110. The fluid channel 101 allows some electrolyte to flow between the shielding member 20 and the pressing member 30. When the pressure within the housing 10 reaches a certain value, the electrolyte can impact the shielding member 20 and further impact the weak portion 110, causing the weak portion 110 to open.

[0118] Please refer to FIG. 8 . In some embodiments, there are multiple protrusions 33 . The multiple protrusions 33 are arranged along the width direction T of the pressing member 30 . At least one protrusion 33 presses the shielding member 20 . A fluid channel 101 is formed between the multiple protrusions 33 .

[0119] Specifically, the number of protrusions 33 can be two, three, four, or even more. Multiple protrusions 33 can be arranged at intervals on the plate 32, forming multiple gaps between the multiple protrusions 33. These gaps can serve as channels for fluid flow, namely, fluid channels 101. The width direction T of the pressing member 30 can be perpendicular to the length direction V of the shielding member 20.

[0120] In this way, the multiple protrusions 33 can increase the contact area between the pressing member 30 and the shielding member 20, allowing the pressing member 30 to effectively press the shielding member 20. The fluid channels 101 formed between the multiple protrusions 33 allow part of the electrolyte to flow along a predetermined flow path, thereby more precisely controlling the flow of the electrolyte. When the pressure within the housing 10 reaches a certain value, the electrolyte flows along the predetermined flow path to impact the shielding member 20, and further impacts the weakened portion 110, causing the weakened portion 110 to open.

[0121] The multiple protrusions 33 can all press against the shielding member 20, and the areas of pressure exerted by each protrusion 33 on the shielding member 20 can be equal or unequal. Please refer to Figures 8 and 9 , which illustrate the positional relationship between the pressing member 30, the shielding member 20, and the weakened portion 110, according to some embodiments of the present application. In some embodiments, the multiple protrusions 33 all press against the shielding member 20, and the areas of pressure exerted by each protrusion 33 on the shielding member 20 are equal.

[0122] Specifically, the number of protrusions 33 can be four, and the areas of the surfaces of the four protrusions 33 facing the shielding member 20 can be the same, and the surfaces of the four protrusions 33 facing the shielding member 20 can completely press against the shielding member 20. The areas of the four protrusions 33 pressing against the shielding member 20 can be P1, P2, P3, and P4, respectively. P1, P2, P3, and P4 are all equal.

[0123] It is worth noting that the number of protrusions 33 here is only an example and should not be understood as a limitation on the implementation methods of the present application.

[0124] In this way, the area of ​​each protrusion 33 pressing against the shielding member 20 is equal, which ensures that the pressure on the shielding member 20 is evenly distributed and does not cause uneven pressure due to a protrusion 33 being too large or too small. This helps to improve the stability of the shielding member 20 and helps to evenly distribute the electrolyte around the weak portion 110.

[0125] Please refer to Figures 7 and 10. Figure 10 is a schematic diagram of the structure of a shielding member 20 provided in some embodiments of the present application. In certain embodiments, shielding member 20 includes a first surface 21 and a second surface 22 that face each other. The protrusion 33 presses against the first surface 21. The contact area between the first surface 21 and the protrusion 33 is S1, and the area of ​​the first surface 21 is S2. S1 and S2 satisfy the following relationship: 20% ≤ S1 / S2 ≤ 80%.

[0126] For example, 25%≤S1 / S2≤80%, 25%≤S1 / S2≤75%, 30%≤S1 / S2≤60%, 20%≤S1 / S2≤60%, 20%≤S1 / S2≤75%, etc.; S1 / S2=20%, S1 / S2=25%, S1 / S2=30%, S1 / S2=60%, S1 / S2=80%, etc.

[0127] Specifically, the first surface 21 may be the surface of the shielding member 20 facing away from the weak portion 110. The first surface 21 may be a flat surface, a curved surface, or a combination of a flat surface and a curved surface. The second surface 22 may be the surface of the shielding member 20 facing the weak portion 110. A portion of the second surface 22 may cover the weak portion 110, while another portion of the second surface 22 may be in contact with the first wall 11. The second surface 22 may be a flat surface, a curved surface, or a combination of a flat surface and a curved surface.

[0128] The shielding member 20 can be a thin sheet-like structure, with the first surface 21 positioned above the second surface 22 along the thickness direction of the shielding member 20. The protrusions 33 can exert pressure on the first surface 21, thereby pressing the second surface 22 against the first wall 11, thereby maintaining a substantially unchanged relative position between the second surface 22 and the first wall 11. The thickness direction of the shielding member 20 can be the same as the thickness direction h of the first wall 11.

[0129] Thus, within this range, the protrusion 33 can effectively press against the first surface 21, thereby stably limiting the position of the shielding member 20 and reducing the probability of the shielding member 20 drifting to other locations due to the flow of electrolyte, allowing the shielding member 20 to continuously cover the weak portion 110. Furthermore, the electrolyte can flow in the area where the protrusion 33 and the first surface 21 do not contact each other. When the pressure within the housing 10 reaches a certain value, the electrolyte can impact the shielding member 20, and further impact the weak portion 110, causing the weak portion 110 to open.

[0130] 8 and 11 , FIG11 is a schematic diagram of the projection relationship between the pressing member 30 and the shielding member 20 provided in some embodiments of the present application. In some embodiments, along the thickness direction h of the first wall 11 , the projection T1 of the pressing member 30 completely covers the projection T2 of the shielding member 20 .

[0131] Specifically, the shape of the pressing member 30 can match the shape of the shielding member 20, so that the shielding member 20 can be located within the area covered by the pressing member 30, making it less likely for the edge of the shielding member 20 to warp, flanging, or other defects to occur, thereby enabling the pressing member 30 to effectively press the shielding member 20. For example, along the thickness direction h of the first wall 11, the surface of the pressing member 30 facing the shielding member 20 can be rectangular, and the surface of the shielding member 20 facing the pressing member 30 can be rectangular. The area of ​​the surface of the pressing member 30 facing the shielding member 20 can be larger than the area of ​​the surface of the shielding member 20 facing the pressing member 30, that is, the projection T1 of the pressing member 30 completely covers the projection T2 of the shielding member 20.

[0132] In this way, along the thickness direction h of the first wall 11, the projection T1 of the pressing member 30 completely covers the projection T2 of the shielding member 20, which makes the shielding member 20 always within the coverage range of the pressing member 30, so that the pressing member 30 can effectively reduce the impact of the electrolyte on the shielding member 20, thereby reducing the probability of the shielding member 20 being free to other positions with the flow of the electrolyte, so that the shielding member 20 can continuously cover the weak part 110.

[0133] Please refer to Figure 12, which is a schematic diagram illustrating the positional relationship between the pressing member 30, the shielding member 20, and the weakened portion 110 according to some embodiments of the present application. In some embodiments, the shielding member 20 has a contact area 23 that contacts the pressing member 30. The contact area 23 is spaced apart from the weakened portion 110 along a direction perpendicular to the thickness of the first wall 11.

[0134] Specifically, the contact area 23 is the portion of the shielding member 20 that directly contacts the pressing member 30. The pressing member 30 presses against the contact area 23, applying pressure to the contact area 23 to keep the relative position between the shielding member 20 and the first wall 11 substantially unchanged.

[0135] The shielding member 20 may be a thin sheet-like structure, and the thickness direction of the shielding member 20 may be the same as the thickness direction h of the first wall 11. The direction perpendicular to the thickness of the first wall 11 may be the length direction V or the width direction of the shielding member 20. For example, the contact area 23 is spaced apart from the weak portion 110 along the length direction V of the shielding member 20.

[0136] In this way, the contact area 23 is spaced from the weak portion 110 in a direction perpendicular to the thickness of the first wall 11, which can reduce the probability of the pressing member 30 contacting the weak portion 110, thereby reducing the probability of the pressing member 30 applying pressure to the weak portion 110, and further reducing the probability of the weak portion 110 opening prematurely under the pressure of the pressing member 30.

[0137] Referring to FIG. 12 , in some embodiments, the width of the weak portion 110 is W1 , and the maximum distance between the plurality of protrusions 33 along the width direction T of the pressing member 30 is W2 , where W1 and W2 satisfy: W2 ≥ W1 + 4, in mm.

[0138] Specifically, along the width direction T of the pressing member 30 , the farthest distance between the plurality of protrusions 33 is the distance between the edges of two protrusions 33 on the outermost sides.

[0139] In this way, the area where the protrusion 33 presses the shielding member 20 can be distributed outside the weak portion 110 , so that the shielding member 20 can be effectively pressed.

[0140] Referring to Figure 12 , in certain embodiments, along the width direction T of the pressing member 30, the maximum distance between the plurality of protrusions 33 is W2, and the width of the shielding member 20 is W3. W2 and W3 satisfy the following relationship: 0 ≤ |W3 - W2| ≤ 10 (unit: mm). Thus, the width W3 of the shielding member 20 approximates the area within which the protrusions 33 can press, effectively pressing the edges of the shielding member 20.

[0141] Please refer to Figures 7 and 8. In some embodiments, the shielding member 20 includes a first part 24, a second part 25 and a bonding structure 26 arranged on the second part 25. The first part 24 is connected to the second part 25. The first part 24 covers at least a portion of the weak portion 110 along the thickness direction h of the first wall 11. The second part 25 is bonded to the first wall 11 through the bonding structure 26, and the pressing member 30 presses the second part 25.

[0142] Specifically, the first portion 24 is used to resist the electrolyte. When the pressure inside the housing 10 does not exceed a threshold, the first portion 24 can reduce the direct effect of the electrolyte on the weak portion 110, thereby reducing the probability of the weak portion 110 opening prematurely.

[0143] The second portion 25 can be integrally formed with the first portion 24 or separately formed. The shielding member 20 includes an adhesive structure 26 disposed on the second portion 25, which allows the second portion 25 to be bonded to the first wall 11. The adhesive structure 26 can protrude from the surface of the second portion 25 and can be made of a material such as epoxy or silicone that is compatible with the internal environment of the housing 10. The internal environment of the housing 10 includes electrolyte, temperature, and the like.

[0144] Furthermore, before bonding, the surfaces of the first wall 11 and the second portion 25 may be appropriately treated to enhance bonding performance and improve bonding adhesion. For example, the surfaces of the first wall 11 and the second portion 25 may be cleaned, dirt removed, and polished.

[0145] In this manner, the first portion 24 covers at least a portion of the weak portion 110 along the thickness direction h of the first wall 11, providing protection for the weak portion 110. The second portion 25 is bonded to the first wall 11 via the bonding structure 26, enabling the shielding member 20 to form a relatively stable connection with the first wall 11. The pressing member 30 presses against the second portion 25, further enhancing the stability of the connection between the shielding member 20 and the first wall 11.

[0146] Please refer to Figure 13, which illustrates the positional relationship between the shielding member 20 and the weakened portion 110 provided in some embodiments of the present application. In some embodiments, the weakened portion 110 can separate the second portion 25 into two separate regions: a first sub-portion 250 and a second sub-portion 251. Along a direction perpendicular to the thickness of the first wall 11, the length L1 of the first sub-portion 250 and the length L2 of the second sub-portion 251 are equal to ensure uniform bonding and prevent defects such as warping or flanging of one of the first sub-portion 250 and the second sub-portion 251.

[0147] Referring to FIG. 7 , in some embodiments, the adhesive structure 26 protrudes from the surface of the second portion 25 . The adhesive structure 26 and the first portion 24 together define a gas channel 113 . The gas channel 113 extends to the edge of the shielding member 20 .

[0148] Specifically, the second portion 25 may be connected to both ends of the first portion 24 , and the second portion 25 may be coplanar with the first portion 24 . The gas channel 113 may communicate with the second groove 112 , and the gas channel 113 may be covered by the first portion 24 .

[0149] In this way, the gas inside the housing 10 can flow to the weak portion 110 through the gas channel 113, thereby allowing the weak portion 110 to open when the pressure inside the housing 10 reaches a certain value, thereby improving the functional stability of the weak portion 110. In addition, the provision of the gas channel 113 also facilitates the detection of the welding condition of the weak portion 110.

[0150] Please refer to Figure 12. In some embodiments, the pressing member 30 includes a width edge 34. Along the length direction V of the covering member 20, the bonding structure 26 includes a first edge 260 and a second edge 261 opposite to the first edge 260. The first edge 260 is close to the width edge 34 relative to the second edge 261. The distance between the first edge 260 and the second edge 261 is A1, and the distance between the first edge 260 and the width edge 34 is A2. A1 and A2 satisfy: 10%≤A1 / A2≤80%.

[0151] For example, the relationship between A1 and A2 can be 10%≤A1 / A2≤75%, 15%≤A1 / A2≤75%, 20%≤A1 / A2≤70%, 20%≤A1 / A2≤60%, 60%≤A1 / A2≤80%, etc. A1 / A2 can be 10%, 15%, 20%, 60%, 80%, etc.

[0152] Specifically, the width edge is the end surface along the length direction of the pressing member 30, and the length direction of the pressing member 30 may be perpendicular to the width direction T of the pressing member 30. In some embodiments, the bonding structure 26 may be symmetrically arranged on the shielding member 20, so A1 and A2 correspond to two sets of values.

[0153] In this way, the pressing member 30 can effectively press the shielding member 20 and further press the area where the bonding structure 26 bonds the shielding member 20 and the first wall 11 , thereby improving the connection strength between the shielding member 20 and the first wall 11 .

[0154] Referring to FIG. 3 , in certain embodiments, a battery cell 100 includes an electrode assembly 40, an insulating film 50, and a connecting piece 60. The insulating film 50 wraps around the electrode assembly 40 and is located on the side of the pressing member 30 facing away from the first wall 11. One end of the connecting piece 60 is connected to the insulating film 50, and the protrusion 33 presses against the other end of the connecting piece 60. The thickness of the shielding member 20 is less than or equal to the thickness of the connecting piece 60. The thickness of the shielding member 20 is the maximum thickness of the entire shielding member 20.

[0155] Specifically, the electrode assembly 40 is the component within the battery cell 100 where the electrochemical reaction occurs. The housing 10 may contain one or more electrode assemblies 40. The electrode assembly 40 is primarily formed by winding or stacking positive and negative electrode sheets, with a separator typically positioned between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active material constitute the electrode body of the electrode assembly 40, while the portions of the positive and negative electrode sheets without active material each constitute the tabs.

[0156] The insulating film 50 is used to isolate the electrode assembly 40 from the inner wall of the housing 10 to reduce the probability of a short circuit caused by direct contact between the electrode assembly 40 and the inner wall. The insulating film 50 can be made of polyester film, polypropylene film, polyethylene film, etc. For example, the insulating film 50 can be polyester film, which has excellent electrical insulation, mechanical properties, and heat resistance, and can effectively reduce the probability of a short circuit in the electrode assembly 40.

[0157] The connecting piece 60 may have a surface that connects to the insulating film 50, and this surface may be bonded to the insulating film 50. One end of the connecting piece 60 may be used to secure the insulating film 50, allowing the insulating film 50 to continuously wrap around the electrode assembly 40 and reduce the probability of functional failure of the insulating film 50. The other end of the connecting piece 60 may be bonded to the pressing member 30 and pressed by the pressing member 30, thereby securing the connecting piece 60.

[0158] Because one end of the connecting piece 60 is fixed to the side of the pressing member 30 facing the first wall 11, the connecting piece 60 occupies a certain amount of space within the housing 10 in the thickness direction h of the first wall 11. The shielding member 20 and the end of the connecting piece 60 fixed to the pressing member 30 can be arranged on the same surface of the pressing member 30. By setting the thickness of the shielding member 20 to be less than or equal to the thickness of the connecting piece 60, the space occupied by the shielding member 20 in the thickness direction h of the first wall 11 can be reduced, thereby improving the utilization of the internal space of the housing 10.

[0159] Please refer to Figures 6, 7, and 14. Figure 14 is an enlarged view of portion b of the cross-sectional view of the first wall 11, shielding member 20, and pressing member 30 in Figure 6. The thickness B1 of the shielding member 20 can be 0.01mm to 3mm, 0.05mm to 2.5mm, 0.1mm to 2mm, 0.5mm to 1mm, 0.01mm to 0.3mm, etc.; the thickness B1 of the shielding member 20 can be 0.01mm, 0.05mm, 0.1mm, 0.3mm, or 3mm. The thickness B2 of the connecting piece 60 can be 0.01mm to 5mm, 0.05mm to 4.5mm, 0.1mm to 4mm, 0.2mm to 3mm, 0.3mm to 0.5mm, etc.; the thickness B2 of the connecting piece 60 can be 0.01mm, 0.2mm, 0.3mm, 0.5mm, 5mm, etc.

[0160] Within these ranges, the shielding member 20 and the connecting piece 60 are easy to manufacture, the shielding member 20 can effectively protect the weak portion 110 , and the connecting piece 60 can effectively stabilize the insulating film 50 .

[0161] In this way, the insulating film 50 can reduce the probability of contact between the electrode assembly 40 and the outer casing 10, thereby reducing the probability of a short circuit in the electrode assembly 40, and thus improving the reliability of the battery cell 100. The connecting piece 60 can fix the insulating film 50, improving the stability of the insulating film 50 wrapped around the electrode assembly 40, and can connect the insulating film 50 and the pressure member 30, reducing the probability of the pressure member 30 moving with the flow of electrolyte. The thickness of the shielding member 20 is less than or equal to the thickness of the connecting piece 60, which can reduce the space occupied by the shielding member 20 in the thickness direction h of the first wall 11 and improve the utilization rate of the internal space of the outer casing 10.

[0162] Please refer to FIG. 3 . In some embodiments, the housing 10 includes a shell 12 and an end cover 13 . The shell 12 is formed with an opening 120 . The end cover 13 covers the opening 120 of the shell 12 . The first wall 11 is located on the shell 12 .

[0163] Specifically, the end cap 13 is a component that covers the opening 120 of the housing 12 to isolate the interior of the housing 10 from the external environment. The housing 12 is a structure of the housing 10 that accommodates components such as the electrode assembly 40. The shape of the opening 120 of the housing 12 can be regular, such as a square, or irregular.

[0164] The battery cell 100 also includes a terminal 70, which is used to electrically connect to the electrode assembly 40 to output or input electrical energy from the battery cell 100. The terminal 70 includes a positive terminal and a negative terminal. The positive and negative terminals are spaced apart on the end cover 13 along the length of the battery cell 100. The length direction of the battery cell 100 can be the same as the length direction V of the shielding member 20.

[0165] During the battery's charge and discharge process, the positive and negative active materials react with the electrolyte, and the tabs are electrically connected to the post 70 to form a current loop. The tabs include a positive tab and a negative tab. The positive tab is used to connect to the positive post, while the negative tab is used to connect to the negative post.

[0166] The battery cell 100 further includes an adapter plate 80 . The positive electrode tab is connected to the positive electrode column via one adapter plate 80 , and the negative electrode tab is connected to the negative electrode column via another adapter plate 80 .

[0167] The first wall 11 may be a wall located in the bottom area of ​​the housing 12. The weak portion 110 may be provided on the wall panel of the housing 12 opposite the end cover plate 13, or may be provided on other side walls of the housing 12. The wall panel provided with the weak portion 110 is the first wall 11. When the housing 10 has weak portions 110 provided on different side walls, that is, when the housing 10 has multiple weak portions 110, the shielding member 20 shields at least a portion of the weak portion 110 located on the bottom wall panel of the housing 10.

[0168] Thus, the end cover 13 can separate the internal environment of the housing 12 from the external environment, preventing the external environment from adversely affecting the internal environment. The first wall 11 is located on the housing 12, so that the weak portion 110 has a larger design space, thereby improving the pressure relief effect of the weak portion 110.

[0169] In other embodiments, the weak portion 110 may be provided on the end cover plate 13 , thereby facilitating replacement of the weak portion 110 .

[0170] Please refer to Figures 3, 4, 5, and 8. In one specific embodiment, a battery cell 100 includes a housing 10, a shielding member 20, and a pressure member 30. The housing 10 has a first wall 11 disposed at the bottom. The first wall 11 has a weakened portion 110, which serves as an explosion-proof valve. The shielding member 20 is a PET membrane, the surface of which faces the first wall 11 and is bonded to the first wall 11. The pressure member 30 serves as a bottom support plate within the battery cell 100.

[0171] Four protrusions 33 are provided on the bottom support plate. All four protrusions 33 can press on the diaphragm. The areas of the four protrusions 33 pressing on the diaphragm are equal, so as to reduce the probability of the diaphragm being free to other positions with the flow of electrolyte, so that the diaphragm can continuously cover the explosion-proof valve.

[0172] Referring to Figure 3 , in certain embodiments, when the battery cell 100 is in use, the first wall 11 serves as the bottom wall of the outer shell 10. Thus, when the battery cell 100 is in use, the shielding member 20 shields the weak portion 110, thereby reducing the probability of the shielding member 20 being dislodged due to the impact of the electrolyte on the bottom wall of the outer shell 10.

[0173] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. 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, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, wherein: The battery cell comprises: A housing, the housing having a first wall, the first wall being provided with a weak portion; a shielding member, the shielding member being disposed in the housing and covering at least a portion of the weak portion along a thickness direction of the first wall; and A pressing member is located at a side of the shielding member away from the first wall, and presses the shielding member.

2. The battery cell according to claim 1, wherein: The pressing member includes a plate body and a protrusion arranged on the plate body, the protrusion presses the shielding member, and the protrusion is used to form a fluid channel.

3. The battery cell according to claim 2, wherein: There are multiple protrusions, and the multiple protrusions are arranged along the width direction of the pressing member. At least one protrusion presses the shielding member, and the fluid channel is formed between the multiple protrusions.

4. The battery cell according to claim 3, wherein: The plurality of protrusions all press against the shielding member, and the area of ​​each protrusion pressing against the shielding member is equal.

5. The battery cell according to claim 3 or 4, wherein: The width of the weak portion is W1, and along the width direction of the pressing member, the farthest distance between the plurality of protrusions is W2, and W1 and W2 satisfy: W2≥W1+4, in mm.

6. The battery cell according to any one of claims 3 to 5, wherein: Along the width direction of the pressing member, the farthest distance between the plurality of protrusions is W2, the width of the shielding member is W3, and W2 and W3 satisfy: 0≤|W3-W2|≤10, in mm.

7. The battery cell according to any one of claims 2 to 6, wherein: The shielding member includes a first surface and a second surface facing each other, the protrusion presses against the first surface, the contact area between the first surface and the protrusion is S1, the area of ​​the first surface is S2, and S1 and S2 satisfy: 20%≤S1 / S2≤80%.

8. The battery cell according to any one of claims 2 to 6, wherein: The battery cell includes an electrode assembly, an insulating film and a connecting sheet. The insulating film wraps the electrode assembly and is located on the side of the pressing member facing away from the first wall. One end of the connecting sheet is connected to the insulating film, and the protrusion presses the other end of the connecting sheet. The thickness of the shielding member is less than or equal to the thickness of the connecting sheet.

9. The battery cell according to any one of claims 1 to 8, wherein: Along the thickness direction of the first wall, the projection of the pressing member completely covers the projection of the shielding member.

10. The battery cell according to any one of claims 1 to 9, wherein: The shielding member has a contact area that contacts the pressing member, and the contact area is spaced apart from the weak portion along a direction perpendicular to the thickness of the first wall.

11. The battery cell according to any one of claims 1 to 10, wherein: The shielding member includes a first part, a second part and a bonding structure arranged on the second part, the first part is connected to the second part, the first part covers at least part of the weak part along the thickness direction of the first wall, the second part is bonded to the first wall through the bonding structure, and the pressing member presses the second part.

12. The battery cell according to claim 11, wherein: The bonding structure protrudes from the surface of the second part, and the bonding structure and the first part together form a gas channel, and the gas channel extends to the edge of the shielding member.

13. The battery cell according to claim 12, wherein: The first wall has a first groove and a second groove, the first groove extends from the outer surface of the first wall to the inner surface of the first wall along the thickness direction of the first wall, the second groove passes through the bottom surface of the first groove and the inner surface of the first wall, the second groove is connected to the gas channel, and the weak portion is arranged in the first groove.

14. The battery cell according to any one of claims 11 to 13, wherein: The pressing member includes a width edge. Along the length direction of the shielding member, the bonding structure includes a first edge and a second edge opposite to the first edge. The first edge is close to the width edge relative to the second edge. The distance between the first edge and the second edge is A1, and the distance between the first edge and the width edge is A2. A1 and A2 satisfy: 10%≤A1 / A2≤80%.

15. The battery cell according to any one of claims 1 to 14, wherein: The housing comprises a shell and an end cover plate. The shell is formed with an opening. The end cover plate covers the opening of the shell. The first wall is located on the shell.

16. The battery cell according to any one of claims 1 to 15, wherein: When the battery cell is in use, the first wall is the bottom wall of the housing.

17. A battery, wherein: The battery comprises the battery cell according to any one of claims 1 to 16.

18. An electrical device, wherein: The electrical equipment comprises the battery cell according to any one of claims 1 to 16 or the battery according to claim 17.

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