Battery monomer

Abstract

The embodiment of the utility model provides a battery monomer, and relates to the technical field of energy storage. The battery monomer comprises a shell, a first pressure relief piece and a second pressure relief piece, the first pressure relief piece divides the space in the shell into a closed battery cell cavity and a closed pressure relief cavity, a naked battery cell is mounted in the battery cell cavity, and the first pressure relief piece can be opened when the air pressure in the battery cell cavity reaches a first threshold value, so that the battery cell cavity is communicated with the pressure relief cavity. The second pressure relief piece is arranged on the shell and can be opened when the air pressure in the battery cell cavity reaches a second threshold value, so that the space in the shell is communicated with the outside, and the first threshold value is smaller than the second threshold value. The battery monomer can be subjected to two times of pressure relief, and the battery monomer after the first time of pressure relief can still be continuously used, so that the actual service time of the battery monomer is prolonged while the safety of the battery monomer is ensured, and the utilization rate of the battery monomer is improved.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of energy storage technology, and specifically to a battery cell. Background Art

[0002] With the rapid development of electrical devices such as electric vehicles, energy storage systems, and portable electronic devices, the safety, stability, and performance requirements for battery cells are increasing. During use, battery cells can generate large amounts of gas due to internal chemical reactions, material aging, or external factors (such as overcharging, short circuits, and high temperatures). This can cause pressure to rise within the cell cavity, leading to serious safety issues such as thermal runaway and explosion.

[0003] Currently, most common battery cells on the market use a pressure relief mechanism to deal with excessive internal pressure. This mechanism typically involves installing one or more pressure relief valves or holes on the battery casing. When the pressure inside the battery cell exceeds a preset threshold, the valves or holes automatically open, releasing the internal pressure and preventing the battery cell from exploding.

[0004] However, the current pressure relief mechanism used by battery cells requires that the explosion-proof valve open to release pressure when the internal pressure of the battery cell reaches a preset threshold, regardless of whether the battery cell's service life has been reached. After the pressure is released, the battery cell can no longer be used, causing premature disposal of battery cells that have not yet reached the end of their lifespan, resulting in low battery cell utilization. Therefore, how to improve battery cell utilization has become a technical problem that needs to be solved. Utility Model Content

[0005] In view of the above problems, an embodiment of the present application provides a battery cell that can be depressurized twice, and the battery cell can continue to be used after the first depressurization, thereby ensuring the safety of the battery cell while extending the actual use time of the battery cell and improving the utilization rate of the battery cell.

[0006] According to one aspect of an embodiment of the present application, a battery cell is provided, comprising: a shell, a first pressure relief member, and a second pressure relief member. The first pressure relief member divides the space within the shell into a sealed battery cell cavity and a sealed pressure relief cavity, wherein a bare battery cell is installed in the battery cell cavity. The first pressure relief member can open when the air pressure in the battery cell cavity reaches a first threshold value, thereby communicating the battery cell cavity and the pressure relief cavity. The second pressure relief member is provided on the shell, and the second pressure relief member can open when the air pressure in the battery cell cavity reaches a second threshold value, thereby communicating the space within the shell with the outside world. The first threshold value is less than the second threshold value.

[0007] This type of battery cell can be depressurized twice, and since the pressure relief chamber is located inside the shell, the bare battery cell is not connected to the outside world after the first pressure relief, so that the battery cell can continue to be used after the first pressure relief, thereby ensuring the safety of the battery cell while extending the actual use time of the battery cell and improving the utilization rate of the battery cell.

[0008] In an optional manner, an electrode terminal connected to the bare battery cell is exposed on the shell, and the electrode terminal is sealed with the first pressure relief member to enclose a pressure relief cavity.

[0009] By enclosing a pressure relief cavity by the electrode terminals and the first pressure relief member, the internal structure of the battery cell can be optimized, and the pressure relief capability of the battery cell can be improved without increasing the volume of the battery cell.

[0010] In one optional embodiment, the electrode terminal includes a positive terminal and a negative terminal, and the pressure relief chamber includes a first pressure relief chamber and a second pressure relief chamber. Two first pressure relief members are provided, the positive terminal is sealedly connected to one of the first pressure relief members and encloses the first pressure relief chamber, and the negative terminal is sealedly connected to the other first pressure relief member and encloses the second pressure relief chamber.

[0011] Pressure relief chambers are provided at both the positive terminal and the negative terminal. When the air pressure in the battery cell chamber reaches a first threshold, the battery cell chamber can be connected to the two pressure relief chambers at the same time for pressure relief, which has a better pressure relief effect. In addition, the structures of the positive terminal and the negative terminal tend to be consistent, which is convenient for installation.

[0012] In one optional embodiment, the electrode terminal includes a positive terminal and a negative terminal. The positive terminal is made of aluminum, and the negative terminal includes an exposed aluminum layer and a copper layer forming the inner wall of the pressure relief chamber. The aluminum and copper layers are integrally formed by stamping, and the copper layer is sealed to the first pressure relief member.

[0013] In this approach, the positive terminal is made entirely of aluminum, which offers excellent conductivity and corrosion resistance, fulfilling its role as the current output terminal in the battery. The negative terminal's composite structure of copper and aluminum layers combines copper's excellent conductivity with aluminum's high corrosion resistance, ensuring smooth current flow and minimizing energy loss.

[0014] In an optional embodiment, a sealing member and a plastic layer are provided between the electrode terminal and the housing. The electrode terminal is fixedly connected to the housing via the plastic layer, and the sealing member seals the gap between the electrode terminal and the housing.

[0015] The provision of the plastic layer and the sealant can not only fix the electrode terminal to the shell, but also seal the gap between the electrode terminal and the shell, thereby isolating the interior of the battery cell from the outside world and ensuring the airtightness of the internal space of the battery cell.

[0016] In an optional manner, the electrode terminal and the first pressure relief member are sealed and connected by welding or bonding.

[0017] The electrode terminal is sealedly connected to the first pressure relief member, so that the pressure relief chamber is not connected to the battery cell chamber when the first pressure relief member is not opened, thereby ensuring the airtightness of the pressure relief chamber and further ensuring the normal use of the pressure relief function.

[0018] In an optional embodiment, the first pressure relief member is a first pressure relief membrane that can break when the air pressure in the battery cell cavity reaches a first threshold, thereby allowing the battery cell cavity and the pressure relief cavity to communicate with each other.

[0019] When the first pressure relief component is set as the first pressure relief membrane, it has a simple structure, occupies a small volume, is easy to install, and the first pressure relief membrane can promptly sense changes in pressure values and respond, thus having high reliability.

[0020] In an optional manner, the second pressure relief member is a pressure relief valve, and the valve port of the pressure relief valve opens when the air pressure in the battery cell cavity reaches a second threshold value.

[0021] The second pressure relief part adopts a separate valve body structure, which is easy to install and can also release a large amount of air pressure in time to ensure the safety of the battery cell.

[0022] In an optional manner, a second pressure relief membrane is provided at the valve port of the pressure relief valve, and the second pressure relief membrane can be damaged when the air pressure in the battery cell cavity reaches a second threshold value, so that the pressure relief cavity is connected to the outside.

[0023] The pressure relief valve releases pressure by rupturing the second pressure relief diaphragm, and can promptly sense and respond to changes in pressure, offering high reliability. Furthermore, this type of pressure relief valve will not reclose once opened, making it a single-use device and offering increased safety.

[0024] In an optional embodiment, the housing includes a cover plate and a bottom shell. The bottom shell is provided with a groove, the cover plate is buckled on the groove and sealed with the groove, so that the sealed groove forms a battery cell cavity, and the pressure relief cavity is provided on the cover plate.

[0025] The cover plate and the bottom shell are combined to form a shell, which makes the shell easy to process and also simplifies the installation process of various components.

[0026] In the battery cell of the embodiment of the present application, in addition to the battery cell cavity for installing the bare battery cell inside the battery cell, a pressure relief cavity is also provided, and the battery cell cavity and the pressure relief cavity are separated by a first pressure relief piece, so that the first pressure relief piece opens when the air pressure in the battery cell cavity reaches a first threshold value, and the battery cell cavity is pressure-relieved for the first time inside the shell. After the first pressure relief, when the air pressure in the battery cell cavity rises to the second threshold value, the second pressure relief piece provided on the shell opens, so that the space in the shell is communicated with the outside world, and the gas inside the shell is released to perform a second pressure relief. In other words, this type of battery cell can be pressure-relieved twice, and since the pressure relief cavity is located inside the shell, the bare battery cell is not communicated with the outside world after the first pressure relief, so that the battery cell can continue to be used after the first pressure relief, thereby extending the actual use time of the battery cell while ensuring the safety of the battery cell and improving the utilization rate of the battery cell.

[0027] The above description is only an overview of the technical solutions of the embodiments of the present application. In order to more clearly understand the technical means of the embodiments of the present application, they can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the embodiments of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0029] Figure 1 A cross-sectional view of a battery cell provided in an embodiment of the present application.

[0030] Figure 2 A schematic diagram of the overall structure of a battery cell provided in an embodiment of the present application.

[0031] Figure 3 This is a partial cross-sectional view of an electrode terminal in a battery cell according to an embodiment of the present application.

[0032] Figure 4 It is a partial cross-sectional view of the positive terminal and the negative terminal of the battery cell involved in the embodiment of the present application.

[0033] Reference numerals:

[0034] 10. Housing; 11. Cover; 12. Bottom shell; 13. Electrode terminal; 131. Positive terminal; 132. Negative terminal;

[0035] 14. Aluminum layer; 15. Copper layer; 16. Sealing element; 17. Plastic layer;

[0036] 20. Battery cell chamber; 30. Pressure relief chamber; 31. First pressure relief chamber; 32. Second pressure relief chamber;

[0037] 40. First pressure relief component; 50. Second pressure relief component; 60. Bare battery cell. DETAILED DESCRIPTION

[0038] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0039] 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 in the specification of the application herein are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0040] The terms "comprises", "comprising" and "having" and any variations thereof in the specification, claims and drawings of this application are intended to cover but not exclude other contents. The word "a" or "an" does not exclude the presence of a plurality.

[0041] References to "embodiments" herein 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 the phrase "embodiment" in various places in the specification does not necessarily refer to the same embodiment, nor does it necessarily refer to independent or alternative embodiments that are 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.

[0042] The term "and / or" in this document simply describes a relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, or B exists alone. Additionally, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0043] The directional words appearing in the following description refer to the directions shown in the drawings and do not limit the specific structure of the battery cells of this application. For example, in the description of this application, the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the drawings and are only for the convenience of describing this application and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore should not be understood as limiting this application.

[0044] In addition, the expressions of the indicated directions such as the X direction, the Y direction, and the Z direction used to illustrate the operation and construction of the various components of the battery cell of this embodiment are not absolute but relative, and although these indications are appropriate when the various components of the battery cell are in the positions shown in the figures, when these positions are changed, these directions should be interpreted differently to correspond to the changes.

[0045] In addition, the terms "first", "second", etc. in the description and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order, and may explicitly or implicitly include one or more such features.

[0046] In the description of this application, unless otherwise specified, "plurality" means more than two (including two), and similarly, "multiple groups" means more than two (including two).

[0047] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood broadly. For example, "connected" or "connected" in a mechanical structure can refer to a physical connection. For example, a physical connection can be a fixed connection, such as a fixed connection via a fixing member, such as a screw, bolt, or other fixing member. A physical connection can also be a detachable connection, such as a mutual snap-fit connection. A physical connection can also be an integral connection, such as a connection formed by welding, bonding, or integral molding. In addition to referring to a physical connection, "connected" or "connected" in a circuit structure can also refer to an electrical connection or a signal connection. For example, it can be a direct connection, i.e., a physical connection, or an indirect connection through at least one intermediate element, as long as the circuit is interconnected. It can also refer to internal communication between two elements. A signal connection can refer to a signal connection through a circuit or a signal connection through a media medium, such as radio waves. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0048] The battery cell provided in this embodiment is as follows Figure 1 and Figure 2 As shown, Figure 1 A cross-sectional view of a battery cell provided in an embodiment of the present application is shown. Figure 2 The overall structure diagram of a battery cell provided in an embodiment of the present application is shown in FIG. The battery cell includes: a housing 10 , a first pressure relief member 40 , a second pressure relief member 50 , a bare cell 60 , and the like.

[0049] The housing 10 forms the battery cell's framework, providing mounting and support for components such as the first and second pressure relief members 40 and 50, and the bare battery cells 60. It also isolates and protects the components within the battery cell from the outside world. Housing 10 is typically constructed of high-strength, corrosion-resistant materials to ensure the stability and safety of the battery cell in complex environments.

[0050] The housing 10 is provided with a receiving space, which can be composed of a plurality of components, such as Figure 1 As shown, in one feasible embodiment, the housing 10 may include a cover plate 11 and a bottom housing 12. The bottom housing 12 is provided with a groove, and the cover plate 11 is snapped onto the groove and sealed therewith, so that the sealed groove forms the battery cell cavity 20. The pressure relief cavity 30 is provided on the cover plate 11. The combination of the cover plate 11 and the bottom housing 12 to form the housing 10 makes the housing 10 easier to process and simplifies the assembly process of various components.

[0051] The first pressure relief member 40 divides the interior of the housing 10 into a sealed cell chamber 20 and a sealed pressure relief chamber 30. The cell chamber 20 houses the bare cell 60, while the pressure relief chamber 30 contains gas. The bare cell 60 is the unit that discharges electricity through a chemical reaction and can also be referred to as an electrode assembly, electrode coil, or the like.

[0052] The first pressure relief member 40 is located between the cell cavity 20 and the pressure relief chamber 30. When the air pressure in the cell cavity 20 is less than a first threshold, the first pressure relief member 40 remains closed, isolating the cell cavity 20 from the pressure relief chamber 30. When the air pressure in the cell cavity 20 reaches the first threshold, the first pressure relief member 40 opens, allowing the cell cavity 20 and the pressure relief chamber 30 to communicate.

[0053] The first pressure relief member 40 can be made of a pressure-sensitive material or set as a mechanical structure to establish a communication relationship between the battery cell cavity 20 and the pressure relief cavity 30 by opening the internal channel or rupturing it, so that the high-pressure gas in the battery cell cavity 20 flows into the pressure relief cavity 30 through the first pressure relief member 40, thereby effectively reducing the pressure in the battery cell cavity 20 and preventing the bare battery cell 60 from being damaged or exploding due to excessive pressure in the space.

[0054] During the use of the battery cell, the bare cell 60 in the cell cavity 20 continuously generates gas, and the air pressure in the cell cavity 20 continuously increases. When the air pressure in the cell cavity 20 rises to a first threshold, the first pressure relief member 40 opens, the cell cavity 20 and the pressure relief chamber 30 communicate with each other, and the gas in the cell cavity 20 enters the pressure relief chamber 30, thereby reducing the air pressure in the cell cavity 20 and preventing the battery cell from exploding. At the same time, after the first pressure relief member 40 opens, the cell cavity 20 and the pressure relief chamber 30 communicate with each other, but not with the outside world. The bare cell 60 remains enclosed inside the shell 10, and the battery cell can continue to be used.

[0055] The second pressure relief member 50 is provided on the shell 10 and can also be made of a pressure-sensitive material or be set as a mechanical structure to open when the air pressure in the battery cell cavity 20 reaches a second threshold, so that the space in the shell 10 is connected to the outside, wherein the first threshold is less than the second threshold.

[0056] The second pressure relief member 50 can withstand higher pressure than the first pressure relief member 40, thereby ensuring that the battery cell is internally depressurized through the first pressure relief member 40 before being externally depressurized through the second pressure relief member 50. The second threshold should be less than or equal to the safe pressure threshold of the cell cavity 20 in which the bare cell 60 is installed. That is, the pressure in the cell cavity 20 will not damage or explode the bare cell 60 when it reaches the second threshold.

[0057] During use of the battery cell, when the air pressure within the cell cavity 20 is less than a first threshold, both the first pressure relief member 40 and the second pressure relief member 50 remain closed, forming separate, enclosed chambers. When the air pressure within the cell cavity 20 rises to the first threshold, the first pressure relief member 40 opens, while the second pressure relief member 50 remains closed, allowing the cell cavity 20 and the pressure relief chamber 30 to communicate. This allows the gas within the cell cavity 20 to enter the pressure relief chamber 30, causing the air pressure within the cell cavity 20 to drop, leading to the first pressure relief. However, the cell cavity 20 and the pressure relief chamber 30 remain sealed by the housing 10, and the function of the battery cell is not affected. After the first pressure relief member 40 is opened, the gas pressure in the battery cell cavity 20 continues to increase with the use of the battery cell. When the gas pressure in the battery cell cavity 20 increases to a second threshold, the second pressure relief member 50 opens, so that the internal space of the shell 10 is connected to the outside world, and the gas in the battery cell cavity 20 is released to the outside world through the second pressure relief member 50, thereby achieving a second pressure relief and preventing the battery cell from exploding.

[0058] In this embodiment, the first pressure relief member 40 can be specifically disposed on a partition between the pressure relief chamber 30 and the cell chamber 20. When the first pressure relief member 40 is not opened, it separates the cell chamber 20 from the pressure relief chamber 30, forming the pressure relief chamber 30 as an independent chamber adjacent to the cell chamber 20. The first pressure relief member 40 automatically opens when the gas pressure within the cell chamber 20 reaches a first threshold, forming a passage connecting the pressure relief chamber 30 and the cell chamber 20, thereby increasing the gas accommodation space and achieving the first pressure relief.

[0059] There can be one or more pressure relief chambers 30, and the pressure relief chamber 30 can be positioned relative to the cell chamber 20 in a variety of ways. Specifically, the pressure relief chamber 30 can be positioned at any position around the cell chamber 20. For example, the pressure relief chamber 30 can be positioned above the cell chamber 20 in the direction of gravity. Alternatively, the pressure relief chamber 30 can be positioned to the side of the cell chamber 20 in the direction of gravity, such as making the direction of the pressure relief chamber relative to the cell chamber 20 perpendicular to the direction of gravity. This is not a limitation.

[0060] The pressure relief component is located inside the housing 10. It can be directly enclosed by the housing 10 or by other components. It is only necessary to ensure that the pressure relief chamber 30 is not in communication with the outside when the second pressure relief component 50 is not opened.

[0061] For example, a feasible implementation method is as follows Figure 1 As shown, the housing 10 is provided with an electrode terminal 13 exposed and connected to the bare battery cell 60 . The electrode terminal 13 is sealed and connected to the first pressure relief member 40 to enclose a pressure relief cavity 30 .

[0062] The electrode terminals 13 are connected to the bare cells 60 via conductive sheets or wires to enable the input and output of electrical energy. They are made of a corrosion-resistant, highly conductive metal material, such as aluminum. The electrode terminals 13 are exposed and positioned in designated locations within the housing 10. The electrode terminals 13 can be provided in pairs or multiple pairs.

[0063] By enclosing the pressure relief cavity 30 by the electrode terminal 13 and the first pressure relief member 40 , the internal structure of the battery cell can be optimized, and the pressure relief capability of the battery cell can be improved without increasing the volume of the battery cell.

[0064] The electrode terminal 13 is structurally configured so that it can enclose a pressure relief member together with the first pressure relief member 40. In a specific embodiment, the electrode terminal 13 can be configured as a hollow structure so that there is a chamber inside the electrode terminal 13 that can accommodate gas. The first pressure relief member 40 is then sealed in connection with the first pressure relief member 40 to block the chamber inside the electrode terminal 13 to form a pressure relief chamber 30.

[0065] The electrode terminal 13 can be configured as a boss structure, specifically a circular or square structure, and its internal cavity can also be configured as a cylindrical or cubic structure, without limitation. The electrode terminal 13 can be stamped from a metal material and can be configured as a single metal layer or a composite structure with multiple metal layers.

[0066] For example, a feasible implementation method is as follows Figure 3 As shown, Figure 3 This is a partial cross-sectional view of an electrode terminal in a battery cell according to an embodiment of the present application. The electrode terminal 13 comprises an exposed aluminum layer 14 and a copper layer 15 that forms the inner wall of the pressure relief chamber 30. The aluminum layer 14 and the copper layer 15 are integrally formed by stamping, and the copper layer 15 is sealed to the first pressure relief member 40.

[0067] In this type of electrode terminal 13, the copper layer 15 has extremely high conductivity and excellent mechanical properties, ensuring low resistance and low energy consumption during current transmission, while also ensuring that the shape of the pressure relief chamber 30 does not easily change. The exposed aluminum layer 14 has excellent conductivity and corrosion resistance, which can extend the service life of the electrode terminal 13. Furthermore, the aluminum layer 14 and the copper layer 15 are integrally formed after stamping, firmly bonding the aluminum layer 14 and the copper layer 15 together, thereby improving the overall connection strength and reliability of the electrode terminal 13.

[0068] The electrode terminal 13 includes a positive terminal 131 and a negative terminal 132. Figure 4 As shown, Figure 4 It is a partial cross-sectional view of the positive terminal and the negative terminal of the battery cell involved in the embodiment of the present application.

[0069] The positive terminal 131 and the negative terminal 132 can both be configured as a composite structure of the aluminum layer 14 and the copper layer 15, or one of them can be configured as a composite structure of the aluminum layer 14 and the copper layer 15. For example, in one feasible embodiment, the positive terminal 131 is an aluminum terminal, and the negative terminal 132 includes an exposed aluminum layer 14 and a copper layer 15 forming the inner wall of the pressure relief chamber. The aluminum layer 14 and the copper layer 15 are integrally formed by stamping, and the copper layer 15 is sealed to the first pressure relief member 40.

[0070] In this method, positive terminal 131 is made entirely of aluminum, which has excellent conductivity and corrosion resistance, meeting the requirements of positive terminal 131 as the current output terminal in the battery. In negative terminal 132, the composite structure of copper layer 15 and aluminum layer 14 combines the excellent conductivity of copper with the high corrosion resistance of aluminum, ensuring smooth current flow and reducing energy loss.

[0071] When the electrode terminal 13 and the first pressure relief member 40 form a pressure relief chamber 30, the pressure relief chamber 30 can be set only at the positive terminal 131 or the negative terminal 132, that is, the pressure relief chamber 30 is formed only by the positive terminal 131 and the first pressure relief member 40, or the pressure relief chamber 30 is formed only by the negative terminal 132 and the first pressure relief member 40.

[0072] Alternatively, you can Figure 4 As shown, pressure relief chambers 30 are provided at both the positive terminal 131 and the negative terminal 132. Specifically, the pressure relief chambers 30 include a first pressure relief chamber 31 and a second pressure relief chamber 32. Two first pressure relief members 40 are provided. The positive terminal 131 is sealedly connected to one first pressure relief member 40, enclosing the first pressure relief chamber 31. The negative terminal 132 is sealedly connected to the other first pressure relief member 40, enclosing the second pressure relief chamber 32.

[0073] A pressure relief chamber 30 is provided at both the positive terminal 131 and the negative terminal 132. When the air pressure in the battery cell chamber 20 reaches a first threshold, the battery cell chamber 20 can simultaneously connect to the two pressure relief chambers 30 for pressure relief, which has a better pressure relief effect. In addition, the structures of the positive terminal 131 and the negative terminal 132 tend to be consistent, which is convenient for installation.

[0074] The electrode terminal 13 and the housing 10 need to be sealed to prevent the space inside the housing 10 from contacting the outside world. There are many ways to seal the connection, such as pressure sealing, welding sealing, etc. For example, a feasible embodiment is as follows Figure 3 As shown, a sealant 16 and a plastic layer 17 may be provided between the electrode terminal 13 and the housing 10. The electrode terminal 13 is fixedly connected to the housing 10 via the plastic layer 17, and the sealant 16 blocks the gap between the electrode terminal 13 and the housing 10.

[0075] The provision of the plastic layer 17 and the seal 16 can not only securely connect the electrode terminal 13 to the housing 10 , but also seal the gap between the electrode terminal 13 and the housing 10 , thereby isolating the interior of the battery cell from the outside and ensuring the airtightness of the internal space of the battery cell.

[0076] The electrode terminal 13 and the first pressure relief member 40 enclose a pressure relief chamber 30. In addition to providing a sealed connection between the electrode terminal 13 and the housing 10, the electrode terminal 13 should also be sealed to the first pressure relief member 40. This prevents the pressure relief chamber 30 from communicating with the cell chamber 20 when the first pressure relief member 40 is closed, ensuring the airtightness of the pressure relief chamber 30 and, in turn, the proper functioning of the pressure relief function. In specific embodiments, the electrode terminal 13 can be sealed to the first pressure relief member 40 by welding or bonding, without limitation.

[0077] In this embodiment, both the first pressure relief member 40 and the second pressure relief member 50 can sense air pressure and open when the air pressure reaches a certain threshold. The first pressure relief member 40 and the second pressure relief member 50 can be configured in many ways, and the two can be similar or completely different, which is not limited here.

[0078] Specifically, the first pressure relief member 40 and the second pressure relief member 50 can be made of pressure-sensitive materials or configured as mechanical structures to be opened by opening a passage therein or by rupturing. There are many specific implementations, which are exemplified below.

[0079] In one embodiment of the first pressure relief member 40 , the first pressure relief member 40 may be a first pressure relief membrane that can break when the pressure in the cell cavity 20 reaches a first threshold, thereby allowing the cell cavity 20 and the pressure relief cavity 30 to communicate with each other.

[0080] The first pressure relief membrane is configured as a thin film to sense the air pressure within the cell cavity 20 and rupture when the air pressure within the cell cavity 20 reaches a first threshold, thereby connecting the cell cavity 20 and the pressure relief cavity 30 and relieving the pressure in the cell cavity 20. The first pressure relief membrane can be made of copper or other materials, as long as it is guaranteed to rupture when the pressure in the cell cavity 20 reaches the first threshold.

[0081] When the first pressure relief member 40 is set as the first pressure relief membrane, it has a simple structure, occupies a small volume, is easy to install, and the first pressure relief membrane can promptly sense changes in the pressure value and respond, and has high reliability.

[0082] In an embodiment of the second pressure relief member 50 , the second pressure relief member 50 is a pressure relief valve, and a valve port of the pressure relief valve opens when the air pressure in the battery cell cavity 20 reaches a second threshold value.

[0083] In this embodiment, the second pressure relief member 50 adopts a separate valve body structure, which is easy to install and can also release a large amount of air pressure in time to ensure the safety of the battery cell.

[0084] Among them, there are many specific structural forms of the pressure relief valve. For example, it can be set as a reed-type pressure relief valve, so that when the air pressure in the pressure relief chamber 30 reaches the second threshold, the spring pushes the reed open to open the pressure relief valve, thereby releasing the air pressure in the battery cell chamber 20.

[0085] Alternatively, the pressure relief valve can also release pressure through a pressure relief membrane. In a specific embodiment, a second pressure relief membrane can be provided at the valve opening of the pressure relief valve. The second pressure relief membrane can break when the air pressure in the battery cell cavity 20 reaches a second threshold, allowing the pressure relief cavity 30 to communicate with the outside world.

[0086] This type of pressure relief valve releases pressure by rupturing the second pressure relief diaphragm, and can promptly sense and respond to changes in pressure, resulting in high reliability. Furthermore, once opened, this type of pressure relief valve will not reclose, making it a single-use device and offering increased safety.

[0087] In addition, in this embodiment, the battery cell structure can be further modified based on the above-described embodiments. For example, a separator, insulating member, or other components can be provided between the bare cell 60 and the housing 10 to insulate the bare cell 60 from the housing, thereby preventing short circuits in the battery cell. Alternatively, a liquid injection hole can be provided in the housing 10 to inject electrolyte into the bare cell 60, and the injection hole can be sealed with a sealant 16, etc., without limitation.

[0088] In summary, in the battery cell described above, in addition to the cell cavity for installing the bare cell inside the battery cell, a pressure relief cavity is also provided, and the cell cavity and the pressure relief cavity are separated by a first pressure relief piece, so that the first pressure relief piece opens when the air pressure in the cell cavity reaches a first threshold value, and the cell cavity is pressure-relieved for the first time inside the shell. After the first pressure relief, when the air pressure in the cell cavity rises to the second threshold value, the second pressure relief piece provided on the shell opens, so that the space inside the shell is communicated with the outside world, and the gas inside the shell is released to perform a second pressure relief. In other words, this type of battery cell can be pressure-relieved twice, and since the pressure relief cavity is located inside the shell, the bare cell is not communicated with the outside world after the first pressure relief, so that the battery cell can continue to be used after the first pressure relief, thereby extending the actual use time of the battery cell while ensuring the safety of the battery cell and improving the utilization rate of the battery cell.

[0089] Those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, combinations of features from different embodiments are intended to be within the scope of this application and to form different embodiments. For example, in the claims, any one of the claimed embodiments may be used in any combination.

[0090] 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 of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery cell, characterized in that: The battery cell comprises: a shell, a first pressure relief member and a second pressure relief member; The first pressure relief member divides the space within the housing into a sealed cell cavity and a sealed pressure relief cavity, wherein a bare cell is installed in the cell cavity, and the first pressure relief member can open when the air pressure in the cell cavity reaches a first threshold, thereby allowing the cell cavity and the pressure relief cavity to communicate with each other; The second pressure relief member is provided on the shell, and can be opened when the air pressure in the battery cell cavity reaches a second threshold value, so that the space in the shell is communicated with the outside; the first threshold value is smaller than the second threshold value.

2. The battery cell according to claim 1, wherein: Electrode terminals connected to the bare battery core are exposed on the shell, and the electrode terminals are sealed with the first pressure relief member to enclose the pressure relief cavity.

3. The battery cell according to claim 2, characterized in that: The electrode terminal includes a positive terminal and a negative terminal; the pressure relief chamber includes a first pressure relief chamber and a second pressure relief chamber; there are two first pressure relief members; The positive terminal is sealed and connected to one of the first pressure relief members to enclose the first pressure relief chamber, and the negative terminal is sealed and connected to the other of the first pressure relief members to enclose the second pressure relief chamber.

4. The battery cell according to claim 2, characterized in that: The electrode terminals include a positive terminal and a negative terminal; The positive terminal is an aluminum terminal; The negative terminal includes an exposed aluminum layer and a copper layer forming the inner wall of the pressure relief chamber; the aluminum layer and the copper layer are integrally formed after stamping, and the copper layer is sealed and connected to the first pressure relief component.

5. The battery cell according to claim 2, characterized in that: A sealing member and a plastic layer are provided between the electrode terminal and the shell; the electrode terminal is fixedly connected to the shell through the plastic layer, and the sealing member blocks the gap between the electrode terminal and the shell.

6. The battery cell according to claim 2, characterized in that The electrode terminal is sealed and connected to the first pressure relief member by welding or bonding.

7. The battery cell according to any one of claims 1 to 6, characterized in that: The first pressure relief member is a first pressure relief membrane; the first pressure relief membrane can be damaged when the air pressure in the battery cell cavity reaches a first threshold value, so that the battery cell cavity and the pressure relief cavity are in communication.

8. The battery cell according to any one of claims 1 to 6, characterized in that: The second pressure relief member is a pressure relief valve, and a valve port of the pressure relief valve opens when the air pressure in the battery cell cavity reaches a second threshold value.

9. The battery cell according to claim 8, characterized in that A second pressure relief membrane is provided at the valve port of the pressure relief valve. The second pressure relief membrane can be damaged when the air pressure in the battery cell cavity reaches a second threshold value, so that the pressure relief cavity is connected to the outside.

10. The battery cell according to claim 1, characterized in that The shell includes a cover plate and a bottom shell; the bottom shell is provided with a groove, the cover plate is buckled on the groove and is sealed with the groove, so that the sealed groove forms the battery cell cavity; the pressure relief cavity is provided on the cover plate.

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