Battery cell, battery device, and electric device

Abstract

The application relates to a battery monomer, a battery device and a power utilization device, comprising a shell, the shell comprising: a first wall, the first wall being configured with a pressure relief port; an explosion-proof valve arranged at the pressure relief port, the explosion-proof valve comprising: a body part arranged in parallel with the first wall; at least one bending part connected with the body part, and at least part of the bending part is arranged to protrude from the body part along the thickness direction of the body part; the tensile strength of at least part of the explosion-proof valve is less than the tensile strength of the first wall, and the yield strength of at least part of the explosion-proof valve is less than the yield strength of the shell. The application can improve the stability of the explosion pressure of the explosion-proof valve and improve the reliability of the battery monomer.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery cell, battery device, and power supply device. Background Technology

[0002] With the gradual popularization of new energy technologies, power battery technology has continued to develop. Power batteries are favored by the new energy industry due to their superior characteristics such as large energy storage capacity, stable power supply capacity, and long service life. Among them, the battery casing, as an important component of the power battery, requires lightweight design while ensuring structural strength.

[0003] In related technologies, the battery includes a casing and an explosion-proof valve. The explosion-proof valve has grooves machined into it, forming a weak point in the entire valve structure. When the internal pressure of the battery reaches or exceeds the pressure that the grooved area can withstand, the material at the grooved area first fractures and expands under pressure, thus causing the explosion-proof valve to open. However, the aforementioned explosion-proof valve exhibits low stability in burst pressure. Utility Model Content

[0004] In view of the above problems, this application provides a battery cell, a battery device, and an electrical device that can improve the stability of the explosion pressure of the explosion-proof valve and improve the reliability of the battery cell.

[0005] In a first aspect, this application provides a battery cell, including a housing, the housing including a first wall, the first wall having a pressure relief port, the tensile strength f of the first wall satisfying the condition: 240MPa≤f≤1000MPa; an explosion-proof valve, disposed at the pressure relief port, the tensile strength e of the explosion-proof valve satisfying the condition: 240MPa≤e≤1000MPa, the explosion-proof valve including a body portion and at least one bent portion, the body portion being arranged parallel to the first wall, the bent portion being connected to the body portion, and at least a portion of the bent portion protruding from the body portion along the thickness direction of the body portion; at least a portion of the tensile strength of the explosion-proof valve is less than the tensile strength of the first wall, and at least a portion of the yield strength of the explosion-proof valve is less than the yield strength of the first wall.

[0006] In the technical solution of this application embodiment, the explosion-proof valve includes a body and at least one bent portion. When the battery cell is working normally, the bent portion can provide stable support to the body, reducing the risk of abnormal opening of the explosion-proof valve due to internal pressure. When the internal pressure of the battery cell increases and pressure relief is required, the bent portion can reduce stress concentration around the pressure relief port that may occur during the pressure relief process, thereby reducing the risk of shell rupture caused by stress concentration. By setting the bent portion to protrude from the body, the bent portion can effectively disperse the impact force generated during the pressure relief process, making the pressure relief process more stable. In addition, the extension direction of the bent portion provides a clear guiding path for the pressure relief process. When the internal pressure of the battery increases and pressure relief is required, the gas can flow more orderly to the pressure relief port along the extension direction of the bent portion, reducing chaos and disorder during the pressure relief process, helping to improve pressure relief efficiency and enhance the reliability of the battery cell. By setting the yield strength of the explosion-proof valve to be lower than that of the casing, when the internal pressure of the battery increases and pressure relief is required, the weak area of ​​the explosion-proof valve will preferentially undergo plastic deformation or fracture, thereby opening the pressure relief port to release the internal pressure. Simultaneously, this helps reduce the stamping difficulty of the bending section and improves the stamping effect of the explosion-proof valve. By setting the tensile strength of both the first wall and the explosion-proof valve within the range of 240MPa to 1000MPa, this application increases the tensile strength of the casing. The higher tensile strength of the casing, compared to the aluminum casing in related technologies, helps to accommodate the high expansion force of high-energy-density cells, thereby withstanding the internal expansion force generated by the high-energy-density cells during charging and discharging, reducing the risk of casing deformation or cracking, and cell leakage, and improving the reliability of the battery cells. However, with high tensile strength, the molding difficulty of the explosion-proof valve is also higher.

[0007] In some embodiments, the bending portion includes a first bending sub-portion and a second bending sub-portion, the first bending sub-portion and the second bending sub-portion being connected and extending intersectingly.

[0008] By setting up a cross-connected first and second bend section, a stable geometric structure is formed. During the pressure relief process, they can support each other and share the pressure, reducing the risk of excessive local deformation or rupture of the explosion-proof valve.

[0009] In some embodiments, the bending portion further includes a third bending sub-portion, which connects the first bending portion and the second bending portion.

[0010] By including the third bend section, stress can be distributed more evenly when the internal pressure of the battery increases, reducing the risk of premature local failure caused by stress concentration, ensuring that the explosion-proof valve remains in a complete sealing state before reaching the design pressure relief pressure, and improving the reliability of the battery cell.

[0011] In some embodiments, the third bend is parallel to the body portion, and the surface away from the body portion is flush with the housing.

[0012] By setting the third bending sub-section parallel to the main body, the overall thickness of the explosion-proof valve is made thinner and does not occupy additional space inside or outside the battery housing; by setting the surface away from the main body to be flush with the housing, it helps to reduce the entry of external dust and other impurities into the pressure relief port, thereby effectively protecting the explosion-proof valve and extending its service life.

[0013] In some embodiments, the third bend extends intersectingly with the body portion.

[0014] By setting a third bending sub-section that extends intersecting with the main body, the effective deformation length and surface area of ​​the explosion-proof valve are increased within a limited space, thereby improving the pressure relief capacity without increasing the overall size.

[0015] In some embodiments, the bending portion includes a plurality of first bending sub-parts and a plurality of second bending sub-parts, which are arranged alternately along the extending direction of the body portion.

[0016] By incorporating multiple bends and secondary bends, the effective pressure relief area of ​​the explosion-proof valve is effectively increased. When the pressure reaches the threshold, the internal high-pressure gas can be released rapidly from multiple parts simultaneously, improving the pressure relief efficiency.

[0017] In some embodiments, the first bending portion and the second bending portion connected thereto together form a bending group; the bending group includes multiple groups, and along the extension direction of the body portion, the multiple bending groups include multiple grooves or multiple protrusions.

[0018] By setting grooves or protrusions, it is possible to enhance the energy resistance to external mechanical impacts and internal pressure fluctuations, thereby extending the service life of the explosion-proof valve.

[0019] In some embodiments, the bend is located within the pressure relief port along the extending direction of the body portion.

[0020] By setting the bend inside the pressure relief port, the pressure relief path can be accurately located, ensuring that when the internal pressure of the battery increases, the gas can only be discharged through the preset explosion-proof valve structure, reducing the disorderly diffusion of gas in the casing, thereby ensuring that the high-pressure gas is concentrated and discharged from the pressure relief port, and improving the pressure relief efficiency.

[0021] In some embodiments, a connecting segment is also included, extending along the body portion, the connecting segment being connected to the side of the bent portion opposite to the body portion and connected to the housing.

[0022] By including the connecting section, when the internal pressure of the battery changes or is subjected to external impact, the connecting section can evenly distribute the stress, preventing the connection between the bent part and the shell from tearing or separating due to stress concentration, significantly enhancing the overall structural stability of the explosion-proof valve and reducing the risk of failure caused by mechanical stress.

[0023] In some embodiments, the minimum distance between the upper end face of the explosion-proof valve and the inner surface of the connecting section is d, wherein d satisfies the condition: 0.2mm≤d≤3mm.

[0024] By limiting the distance between the upper end face of the explosion-proof valve and the inner surface of the connecting section, the explosion-proof valve and the inner surface of the connecting section maintain a small gap in the non-pressure relief state, which not only prevents rigid contact wear, but also fills the gap with sealing materials (such as adhesive layer, sealing ring) to form a reliable static seal and prevent external moisture and dust from entering.

[0025] In some embodiments, the angle between the first bent portion and the extending direction of the body portion is A, and A satisfies the condition: 10°≤A≤45°.

[0026] By limiting the range of the angle between the first bending sub-section and the extension direction of the main body, the deformation of the explosion-proof valve under pressure cycling is concentrated in the bending area, reducing the risk of stress diffusion to the main body or connecting section.

[0027] In some embodiments, the angle between the second bending portion and the extending direction of the main body portion is B, and B satisfies the condition: 45°≤B≤90°.

[0028] By limiting the range of the angle between the second bending sub-section and the extension direction of the main body, it helps to prevent stress concentration at a single bending point, disperse pressure to multiple areas, and enhance the reliability of the explosion-proof valve under complex loads.

[0029] In some embodiments, the yield strength α of the explosion-proof valve satisfies the condition: 140MPa≤a≤500MPa.

[0030] Setting the yield strength α of the explosion-proof valve between 140MPa and 500MPa helps ensure the structural integrity of the housing and allows it to withstand higher mechanical impacts.

[0031] In some embodiments, the yield strength b of the first wall satisfies the condition: 140MPa≤b≤1000MPa.

[0032] By setting the yield strength b of the first wall between 140MPa and 1000MPa, on the one hand, the structural strength of the shell is effectively ensured, thereby providing effective support for the explosion-proof valve; on the other hand, the strength is within a suitable range, reducing the problem that the shell is too rigid as a whole due to excessive strength, and cannot effectively deform and absorb energy.

[0033] In some embodiments, the tensile strength of the explosion-proof valve is less than or equal to the tensile strength of the first wall.

[0034] By setting the tensile strength of the explosion-proof valve to be less than or equal to the tensile strength of the first wall, when the internal pressure exceeds the threshold, the explosion-proof valve, as a preset "weak link", will rupture or open preferentially due to its lower tensile strength, guiding the pressure release direction to a preset path.

[0035] In some embodiments, the tensile strength e of the explosion-proof valve satisfies the condition: 240MPa≤e≤600MPa.

[0036] By setting the tensile strength e of the explosion-proof valve between 240MPa and 600MPa, it has high tensile strength and fracture toughness, which can effectively reduce the risk of the explosion-proof valve breaking under impact load and ensure that the pressure relief process is stable and controllable.

[0037] In some embodiments, the tensile strength f of the first wall satisfies the condition: 240MPa≤f≤1000MPa.

[0038] By setting the tensile strength f of the casing between 240MPa and 1000MPa, the fatigue resistance is high, and it can withstand pressure cycles without fatigue fracture, thus improving the reliability of the battery cell.

[0039] In some embodiments, the explosion-proof valve includes grooves that are disposed on the body portion and surround the outer periphery of the bend portion along the extending direction of the body portion.

[0040] By setting grooves, the local strength is further weakened, ensuring that the explosion-proof valve opens first to release pressure when the battery is over-voltage; at the same time, the matching of the groove position with the tensile strength can make the explosion-proof valve more evenly stressed during the opening process, prolong the effective pressure relief time and improve the pressure relief efficiency.

[0041] In some embodiments, the Vickers hardness of the explosion-proof valve is c, and the Vickers hardness of the housing is d, wherein c and d satisfy the condition: c≤d.

[0042] By setting the Vickers hardness of the explosion-proof valve to be less than or equal to that of the shell, the explosion-proof valve with lower hardness is easier to stamp and form, and ensures that the explosion-proof valve can break preferentially, providing moderate plastic deformation capacity to absorb impact energy; the shell with higher hardness helps to maintain the overall rigidity of the shell and resist external mechanical impact.

[0043] In some embodiments, the Vickers hardness c of the explosion-proof valve satisfies the condition: 100MPa≤c≤250MPa.

[0044] By setting the Vickers hardness c of the explosion-proof valve between 100MPa and 250MPa, on the one hand, it helps to ensure the basic structural strength of the explosion-proof valve and maintain its morphological stability; on the other hand, it helps to maintain sufficient plasticity to ensure controllable rupture in the event of thermal runaway.

[0045] In some embodiments, the Vickers hardness d of the shell satisfies the condition: 100MPa≤d≤380MPa.

[0046] Setting the Vickers hardness d of the casing between 100MPa and 380MPa helps ensure basic resistance to deformation while withstanding higher mechanical impacts, thus improving the reliability of the battery cells.

[0047] In some embodiments, the thickness of the explosion-proof valve is T, and T satisfies the following condition:

[0048] 0.05mm≤T≤0.5mm.

[0049] By setting the thickness T of the explosion-proof valve between 0.05mm and 0.5mm, it is possible to ensure that the explosion-proof valve has sufficient mechanical strength to resist daily external forces while maintaining its durability under multiple pressure cycles.

[0050] In some embodiments, the housing includes: a shell body configured with an opening;

[0051] An end cap covers the opening, the end cap having the pressure relief port, and the end cap serving as the first wall.

[0052] The battery features a split-design housing and end caps. The end caps cover the openings, effectively dispersing the internal pressure of the battery and sharing the mechanical load with the housing. This enhances the overall pressure and impact resistance of the housing and ensures the structural integrity of the battery under complex conditions such as vibration and collision.

[0053] In some embodiments, the end cap is thicker than the shell wall thickness.

[0054] By setting the thickness of the end cap to be greater than the wall thickness of the casing, the end cap can withstand higher mechanical loads, improving the reliability of the battery cell. The casing can be appropriately thinned, which helps to reduce the overall weight of the casing while still maintaining the necessary support function.

[0055] In some embodiments, the end cap has a thickness of h1, which satisfies the condition: 0.5mm ≤ h1 ≤ 1.5mm; the shell has a wall thickness of h2, which satisfies the condition: 0.1mm ≤ h2 ≤ 0.4mm.

[0056] By setting the wall thickness h2 of the casing between 0.1mm and 0.4mm, on the one hand, it helps to ensure that the casing has sufficient mechanical support to prevent deformation during battery assembly or transportation; on the other hand, it can effectively control the weight of the casing.

[0057] In some embodiments, the housing includes a first end plate that surrounds the periphery of the pressure relief port and is connected to the connecting section.

[0058] The first end plate, tightly connected to the connecting section, forms a robust mechanical support structure. When the explosion-proof valve opens to release pressure, the impact force generated by the high-pressure gas is transmitted to the first end plate through the connecting section. Its annular structure can evenly distribute stress, preventing tearing or deformation around the pressure relief port due to stress concentration. This enhances the integrity and reliability of the casing during the pressure relief process and improves the reliability of the battery cells.

[0059] In some embodiments, the battery cell includes a protective patch; the end cap includes a second end plate, which is arranged around the outer periphery of the first end plate away from the pressure relief port; the protective patch is connected to the second end plate and covers the explosion-proof valve.

[0060] By including protective patches, it can effectively resist external mechanical impact and friction, protect critical parts such as scratches and bends of the explosion-proof valve from damage, and ensure that it can perform its pressure relief function normally when the battery is over-voltage.

[0061] In some embodiments, the housing comprises a titanium shell or a steel shell.

[0062] By using titanium or steel shells, the shell strength is high, and it has the advantages of high-energy chemical system and lightweight high strength. There is a tendency to use shells with thinner walls and higher strength, which helps to adapt to the high expansion force of high energy density cells and improve the reliability of battery cells. At the same time, the molding of explosion-proof valves is more difficult when using titanium or steel shells.

[0063] In some embodiments, the housing is a structural component made of any one of TA1, TA4G, or TC4.

[0064] The casing made of the aforementioned materials has excellent strength and corrosion resistance, and can withstand the internal expansion force generated by the high energy density battery cell during charging and discharging, reducing the risk of casing deformation or cracking.

[0065] In some embodiments, the explosion-proof valve is a structural component made of TA1 or TA2.

[0066] Explosion-proof valves made from the aforementioned materials have low yield strength and excellent plasticity, making them easy to form into thin-walled explosion-proof valve structures through stamping processes, thereby ensuring accurate opening and pressure relief under predetermined pressure.

[0067] In some embodiments, the battery is a prismatic battery.

[0068] Secondly, this application provides a battery device that includes the battery cell described in the above embodiments.

[0069] When the battery device provided in this application embodiment is in use, the explosion-proof valve includes a body and at least one bent portion. During normal operation of the battery cell, the bent portion provides stable support to the body, reducing the risk of abnormal opening of the explosion-proof valve due to internal pressure. When the internal pressure of the battery cell increases and pressure relief is required, the bent portion reduces stress concentration around the pressure relief port during the pressure relief process, thereby reducing the risk of casing rupture caused by stress concentration. By setting the bent portion to protrude from the body, the bent portion can effectively disperse the impact force generated during pressure relief, making the pressure relief process smoother. Furthermore, the extension direction of the bent portion provides a clear guiding path for the pressure relief process. When the internal pressure of the battery increases and pressure relief is required, the gas can flow more orderly towards the pressure relief port along the extension direction of the bent portion, reducing chaos and disorder during the pressure relief process, helping to improve pressure relief efficiency and enhance the reliability of the battery cell. By setting the yield strength of the explosion-proof valve to be lower than that of the casing, when the internal pressure of the battery increases and pressure relief is required, the weak area of ​​the explosion-proof valve will preferentially undergo plastic deformation or fracture, thereby opening the pressure relief port to release the internal pressure. Simultaneously, this helps reduce the stamping difficulty of the bending section and improves the stamping effect of the explosion-proof valve. By setting the tensile strength of both the first wall and the explosion-proof valve within the range of 240MPa to 1000MPa, this application increases the tensile strength of the casing. The higher tensile strength of the casing, compared to the aluminum casing in related technologies, helps to accommodate the high expansion force of high-energy-density cells, thereby withstanding the internal expansion force generated by the high-energy-density cells during charging and discharging, reducing the risk of casing deformation or cracking, and cell leakage, and improving the reliability of the battery cells. However, with high tensile strength, the molding difficulty of the explosion-proof valve is also higher.

[0070] Thirdly, this application provides an electrical device, including the battery device in the above embodiments, wherein the battery device is used to provide electrical energy.

[0071] When the electrical device provided in this application embodiment is in use, the battery device composed of the battery cells provided in this application embodiment provides electrical energy to the electrical device. The explosion-proof valve includes a body and at least one bent portion. When the battery cell is working normally, the bent portion can stably support the body, reducing the abnormal opening of the explosion-proof valve due to the influence of internal pressure. When the internal pressure of the battery cell increases and needs to be released, the bent portion can reduce the stress concentration around the pressure relief port that may occur during the pressure relief process, thereby reducing the risk of shell rupture caused by stress concentration. By setting the bent portion to protrude from the body, the bent portion can effectively disperse the impact force generated during the pressure relief process, making the pressure relief process more stable. In addition, the extension direction of the bent portion provides a clear guiding path for the pressure relief process. When the internal pressure of the battery increases and needs to be released, the gas can flow more orderly to the pressure relief port along the extension direction of the bent portion, reducing the chaos and disorder during the pressure relief process, helping to improve the pressure relief efficiency and enhance the reliability of the battery cell. By setting the yield strength of the explosion-proof valve to be lower than that of the casing, when the internal pressure of the battery increases and pressure relief is required, the weak area of ​​the explosion-proof valve will preferentially undergo plastic deformation or fracture, thereby opening the pressure relief port to release the internal pressure. Simultaneously, this helps reduce the stamping difficulty of the bending section and improves the stamping effect of the explosion-proof valve. By setting the tensile strength of both the first wall and the explosion-proof valve within the range of 240MPa to 1000MPa, this application increases the tensile strength of the casing. The higher tensile strength of the casing, compared to the aluminum casing in related technologies, helps to accommodate the high expansion force of high-energy-density cells, thereby withstanding the internal expansion force generated by the high-energy-density cells during charging and discharging, reducing the risk of casing deformation or cracking, and cell leakage, and improving the reliability of the battery cells. However, with high tensile strength, the molding difficulty of the explosion-proof valve is also higher.

[0072] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0073] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0074] Figure 1 The electrical device provided in some embodiments of this application is a structural schematic diagram of a vehicle.

[0075] Figure 2 This is an exploded structural diagram of a battery device provided in some embodiments of this application.

[0076] Figure 3 Axial view of a battery cell provided for some embodiments of this application.

[0077] Figure 4 This is a top view of a battery cell provided in some embodiments of this application.

[0078] Figure 5 Axial view of a battery cell provided for other embodiments of this application.

[0079] Figure 6 Exploded views of a single battery cell provided in some embodiments of this application.

[0080] Figure 7 The battery cells provided in some embodiments of this application are Figure 4 The diagram shows a cross-section at point AA.

[0081] Figure 8 for Figure 7 A magnified schematic diagram of the structure at point A in the middle.

[0082] Figure 9 for Figure 8 A magnified schematic diagram of the structure at point B in the middle.

[0083] Figure 10 This is a cross-sectional schematic diagram of a battery cell provided in some embodiments of this application.

[0084] The reference numerals in the detailed embodiments are as follows:

[0085] 10000 - Vehicles;

[0086] 1000-battery;

[0087] 1100-cell battery;

[0088] 100 - Shell; 110 - First wall; 111 - Pressure relief port; 112 - First end plate; 113 - Second end plate; 120 - Shell body;

[0089] 200 - Explosion-proof valve; 210 - Body; 220 - Bending section; 221 - First bending section; 222 - Second bending section; 223 - Third bending section; 230 - Connecting section; 240 - Score;

[0090] 300-Protective Patch;

[0091] 1200 - Box body; 1210 - Storage space; 1220 - First section; 1230 - Second section;

[0092] 2000-Controller;

[0093] 3000-motor. Detailed Implementation

[0094] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0095] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0096] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0097] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0098] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0099] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0100] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0101] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0102] Currently, judging from market trends, the application of power batteries is becoming increasingly widespread. Power batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of power battery applications, market demand is also constantly increasing.

[0103] A typical battery cell includes a casing and an explosion-proof valve. Specific areas of the explosion-proof valve are machined with grooves, creating a weak point in the entire valve structure. When the internal pressure of the battery reaches or exceeds the pressure that the grooved area can withstand, the material at the groove will first fracture and expand under pressure, thus opening the explosion-proof valve. During cyclic charging and discharging, the battery cell assembly undergoes hard expansion, leading to leakage. To address this issue, steel-cased battery cells are used. However, for designs requiring lightweight battery cells, the introduction of steel casings results in excessive weight.

[0104] To address the issue of excessive weight in individual battery cells, the applicant's research revealed that to achieve higher energy density and gravimetric energy density, battery cell assemblies utilize high-energy chemical systems and lightweight, high-strength casings, leading to a trend towards thinner-walled, high-strength casings. Therefore, the applicant introduced the development of titanium-cased battery cells, achieving both high strength and reduced weight. However, the applicant also considered that titanium casings cannot be welded to aluminum or steel explosion-proof valves. Therefore, the applicant needed to develop titanium explosion-proof valves, while simultaneously ensuring high-precision stamping of these valves and enabling welding to the titanium casing base plate.

[0105] Based on the above considerations, in order to achieve high-precision machining of the explosion-proof valve while ensuring the structural strength of the casing, this application provides a battery cell. By providing a main body and a bent portion, with the bent portion protruding from the main body, stress concentration around the pressure relief port that may occur during pressure relief can be reduced, thereby reducing the risk of casing rupture due to stress concentration. By setting the yield strength of the explosion-proof valve to be lower than that of the casing, when the internal pressure of the battery rises and pressure relief is required, the weak area of ​​the explosion-proof valve will preferentially undergo plastic deformation or fracture, thereby opening the pressure relief port to release the internal pressure; at the same time, it helps to reduce the stamping difficulty of the bent portion and improve the stamping effect of the explosion-proof valve.

[0106] The power batteries manufactured using the battery cells disclosed in the embodiments of this application can be used, but are not limited to, in electrical devices such as vehicles, ships, or aircraft. Specifically, the electrical devices can be, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Among them, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0107] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device according to an embodiment of this application.

[0108] Please see Figure 1 , Figure 1 The diagram shows the structural features of a vehicle provided in some embodiments of this application.

[0109] Vehicle 10000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Vehicle 10000 has a battery internally installed, which can be located at the bottom, front, or rear of the vehicle. The battery can be used to power vehicle 10000; for example, it can serve as the operating power source for vehicle 10000. Vehicle 10000 may also include a controller 2000 and a motor 3000. The controller 2000 is used to control the battery to power the motor 3000, for example, to meet the power needs of vehicle 10000 during starting, navigation, and driving.

[0110] In some embodiments of this application, the battery can not only serve as the operating power source for the vehicle 10000, but also as the driving power source for the vehicle 10000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 10000.

[0111] Please see Figure 2 , Figure 2 Exploded views of batteries provided for some embodiments of this application.

[0112] The battery includes a housing 1200 and battery cells 1100, with the battery cells 1100 housed within the housing 1200. The housing 1200 provides a receiving space 1210 for the battery cells 1100, and the housing 1200 can have various structures. In some embodiments, the housing 1200 may include a first portion 1220 and a second portion 1230, which overlap each other, and together define the receiving space 1210 for accommodating the battery cells 1100. The second part 1230 can be a hollow structure with one end open, and the first part 1220 can be a plate-like structure. The first part 1220 covers the open side of the second part 1230 so that the first part 1220 and the second part 1230 together define the receiving space 1210. Alternatively, the first part 1220 and the second part 1230 can both be hollow structures with one side open, and the open side of the first part 1220 covers the open side of the second part 1230. Of course, the box 1200 formed by the first part 1220 and the second part 1230 can be of various shapes, such as a cylinder, a cuboid, etc.

[0113] In a battery, there can be multiple battery cells 1100, which can be connected in series, parallel, or a combination thereof. A combination thereof means that multiple battery cells 1100 are connected in both series and parallel. Multiple battery cells 1100 can be directly connected in series, parallel, or a combination thereof, and then the entire assembly of the multiple battery cells 1100 is housed within a casing 1200. Alternatively, the battery can be composed of multiple battery cells 1100 first connected in series, parallel, or a combination thereof to form a battery module, and then multiple battery modules are connected in series, parallel, or a combination thereof to form a whole, which is also housed within the casing 1200. The battery may also include other structures; for example, the battery may include a busbar component for electrical connection between the multiple battery cells 1100.

[0114] Each battery cell 1100 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited to these. The battery cell 1100 can be cylindrical, flat, cuboid, or other shapes.

[0115] Please refer to Figure 3 , Figure 3 This is a schematic diagram of the structure of a battery cell provided in some embodiments of this application. A battery cell 1100 refers to the smallest unit that makes up a battery. The battery cell 1100 includes a housing 120, an end cap, a cell assembly, and other functional components.

[0116] An end cap is a component that covers the opening of the housing 120 to isolate the internal environment of the battery cell from the external environment. The shape of the end cap can be adapted to the shape of the housing 120 to fit it. Optionally, the end cap can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap is less prone to deformation under pressure and impact, allowing the battery cell to have higher structural strength and improved safety performance. Functional components such as electrode terminals can be provided on the end cap. The electrode terminals can be used for electrical connection with the cell assembly to output or input electrical energy to the battery cell. In some embodiments, the end cap can also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of the battery cell reaches a threshold. The end cap can also be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose any special limitations on this. In some embodiments, an insulating structure can also be provided on the inner side of the end cap. The insulating structure can be used to isolate the electrical connection components inside the housing 120 from the end cap to reduce the risk of short circuits. For example, the insulating structure can be made of plastic, rubber, etc.

[0117] The housing 120 is a component used to cooperate with the end cap to form the internal environment of a battery cell. This internal environment can accommodate the cell assembly, electrolyte, and other components. The housing 120 and the end cap can be independent components. An opening can be provided on the housing 120, and the end cap closes the opening to form the internal environment of the battery cell. Alternatively, the end cap and housing 120 can be integrated. Specifically, the end cap and housing 120 can form a common connecting surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 120, the end cap is then closed onto the housing 120. The housing 120 can have various shapes and sizes, such as cuboid, cylindrical, or hexagonal prism. Specifically, the shape of the housing 120 can be determined according to the specific shape and size of the cell assembly. The housing 120 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, or plastic. This application embodiment does not impose any special limitations on this.

[0118] A battery cell assembly is the component within a single battery cell where electrochemical reactions occur. The casing 120 may contain one or more battery cell assemblies. The battery cell assembly is primarily formed by stacking composite material strips, which are thermally bonded together with a positive electrode, a negative electrode, and a separator between the positive and negative electrodes. The portions of the positive and negative electrodes containing active material constitute the main body of the battery cell assembly, while the portions without active material each constitute a tab. The positive and negative tabs may be located together at one end of the main body or separately at both ends. During the charging and discharging process of the battery device, the positive and negative active materials react with the electrolyte, and the tabs connect to the electrode terminals to form a current loop.

[0119] The following section provides a detailed description of the structure of a single battery cell. Please refer to [link / reference needed]. Figures 3-10 , Figure 3 Axial views of a battery cell provided in some embodiments of this application are shown. Figure 4 The following is a top view of a battery cell provided in some embodiments of this application. Figure 5 Axial views of a battery cell provided in other embodiments of this application are shown. Figure 6 Exploded views of battery cells provided in some embodiments of this application are shown. Figure 7 This application illustrates some embodiments of the battery cells provided in... Figure 4 The cross-sectional diagram at point AA is shown below. Figure 8 It shows Figure 7 A magnified view of the structure at point A in the middle. Figure 9 It shows Figure 8 A magnified schematic diagram of the structure at point B in the middle. Figure 10 A cross-sectional schematic diagram of a battery cell provided in some embodiments of this application is shown.

[0120] Please see Figure 3 and Figure 4 This application provides a battery cell, and in this embodiment, a prismatic battery cell is used as an example for illustration.

[0121] like Figure 5 and Figure 6 The battery cell 1100 includes a housing 100 and an explosion-proof valve 200. The housing 100 includes a first wall 110, which has a pressure relief port 111. The explosion-proof valve 200 is located at the pressure relief port 111.

[0122] It should be noted that the battery cell 1100 provided in this application embodiment has a split-structure design for its housing 100, consisting of a housing body 120 and an end cap. The end cap serves as the first wall 110, and the housing body 120 is tightly connected to the end cap, forming a closed cavity to accommodate components such as the battery cell assembly. The end cap and housing body 120 cooperate in terms of material properties and structural design to jointly constitute the safety protection system of the battery cell 1100, ensuring the stable operation of the battery cell 1100 during charging and discharging.

[0123] like Figure 6 The first wall 110 has a pressure relief port 111. This port 111 is a through-hole that extends along the thickness of the first wall 110, penetrating both the inner and outer surfaces to form a connecting channel, thus ensuring pressure can be released through this channel. An explosion-proof valve 200 is located at the pressure relief port 111. Initially, the pressure relief port 111 is sealed. When the internal pressure of the battery reaches a threshold, the pressure relief port 111 connects the inside and outside to release pressure.

[0124] In some of these embodiments, such as Figure 7 and Figure 8 The explosion-proof valve 200 may include a body portion 210 and at least one bent portion 220. The body portion 210 is arranged parallel to the first wall 110, and the body portion 210 is connected to the bent portion 220. At least a portion of the bent portion 220 protrudes from the body portion 210 along its thickness direction. The number of bent portions 220 is not limited and can be set according to the type and operating conditions of the battery cell 1100. This embodiment does not impose such a limitation.

[0125] The main body 210 serves as the main part of the explosion-proof valve 200, undertaking basic connection and load-bearing functions. The bent part 220 is connected to the main body 210. This structure can be produced through processes such as stamping and injection molding. During the production process, controlling the mold precision and molding parameters helps to improve the structural consistency of the battery cell 1100.

[0126] At least a portion of the bent portion 220 protrudes from the body portion 210. The protrusion may include: the bent portion 220 protruding inward along the thickness direction of the body portion 210, or the bent portion 220 protruding outward along the thickness direction of the body portion 210. This embodiment does not limit this.

[0127] The aforementioned structure creates multiple stress concentration areas under pressure. When the internal pressure of the battery increases, these stress concentration points preferentially undergo plastic deformation or rupture, causing the explosion-proof valve 200 to open and release pressure at a preset pressure threshold. Simultaneously, the protruding bend 220 alters the gas discharge path, creating a turbulence effect as the airflow passes through the explosion-proof valve 200. This reduces the gas discharge velocity, minimizing the impact of high-speed airflow on internal battery components. Furthermore, by adjusting the protrusion angle and method, the pressure relief direction can be guided to a safe area, reducing damage to battery gas components or the external environment caused by high-temperature, high-pressure gas injection, and improving the reliability of the battery cell 1100.

[0128] To further improve the accurate opening and pressure relief of the explosion-proof valve 200, in some embodiments, at least a portion of the explosion-proof valve 200 has a yield strength less than that of the housing 100.

[0129] It should be noted that yield strength refers to the minimum stress value when a material undergoes plastic deformation under the action of external force. It marks the critical point when a material transitions from the elastic deformation stage (deformation is fully restored after the external force is removed) to the plastic deformation stage (residual permanent deformation after the external force is removed).

[0130] The method for testing yield strength can include tensile testing. The principle is to apply an axial tensile load to the specimen, record the stress-strain curve, and determine the stress value at which the material yields. The testing steps include: preparing the specimen, machining it to a standard shape according to standards, ensuring a smooth and defect-free surface; clamping the specimen in the fixture of a tensile testing machine, ensuring the axis is aligned with the load direction, loading at a constant rate, and simultaneously recording load-displacement data; determining the yield strength. A yield plateau appears on the curve (the strain continues to increase without an increase in load), and the corresponding stresses are the upper yield strength (the maximum stress at the first drop) and the lower yield strength (the average stress during the plateau phase). The lower yield strength is usually taken as the material's yield strength.

[0131] At least a portion of the explosion-proof valve 200 has a yield strength lower than that of the housing 100, meaning that certain parts of the explosion-proof valve 200 will undergo plastic deformation or fail under lower stress than the housing 100. Thus, when the internal pressure of the battery is too high, stress will act on both the housing 100 and the explosion-proof valve 200 simultaneously. On one hand, because the explosion-proof valve 200 has a lower yield strength, it enters the plastic deformation stage before the housing 100, forming cracks or opening the pressure relief port 111, guiding the pressure release direction to a preset path to protect the battery cell 1100 and prevent damage to the housing 100 due to overload. On the other hand, the housing 100, due to its higher yield strength, does not enter the plastic deformation stage and can still maintain its basic structural integrity, helping to prevent the risk of electrolyte leakage or external air intrusion.

[0132] It should be noted that during the cyclic charging and discharging process, the battery cell assembly undergoes hard expansion, leading to leakage. To further adapt to the high expansion force of high-energy-density cells and achieve higher unit energy density and gravimetric energy density in the cell assembly, thus reducing leakage, the tensile strength of the casing 100 can be set higher in this embodiment. Specifically, in this embodiment, the tensile strength e of the explosion-proof valve 200 can satisfy the condition: 240MPa≤e≤1000MPa, and the tensile strength f of the first wall 110 can satisfy the condition: 240MPa≤f≤1000MPa.

[0133] In some embodiments, the tensile strength e of the explosion-proof valve 200 can be 240 MPa, 340 MPa, 440 MPa, 500 MPa, 550 MPa, 580 MPa, 600 MPa, 1000 MPa, or any value between 240 MPa and 1000 MPa. This embodiment does not limit this. The tensile strength f of the first wall 110 can be 240 MPa, 340 MPa, 440 MPa, 500 MPa, 550 MPa, 580 MPa, 600 MPa, 700 MPa, 800 MPa, 900 MPa, 1000 MPa, or any value between 240 MPa and 600 MPa. This embodiment does not limit this.

[0134] By setting the tensile strength of both the explosion-proof valve 200 and the first wall 110 within the range of 240MPa to 1000MPa, this application increases the tensile strength of the housing 100. The housing 100 has a higher tensile strength. Compared with the aluminum-cased explosion-proof valve in the related technology, the housing 100 with higher tensile strength in this application helps to adapt to the high expansion force of high-energy-density cells, thereby withstanding the internal expansion force generated by high-energy-density cells during charging and discharging, reducing the risk of deformation or breakage of the housing 100, and improving the reliability of the battery cell. At the same time, under the background of high tensile strength, the molding difficulty of the explosion-proof valve 200 is higher.

[0135] Tensile strength refers to the maximum ability of a material to resist fracture under axial load. It reflects the maximum stress a material can withstand during tension. When the external force reaches the tensile strength, the material will fracture due to local shrinkage. A tensile testing machine can be used to apply axial tension to the specimen, record the data from deformation to fracture, plot a stress-strain curve, and find the stress value corresponding to the highest point of the curve, which is the tensile strength.

[0136] In some embodiments, to further adapt to the high expansion force of high-energy-density battery cells and withstand the internal expansion force generated during charging and discharging, thereby reducing the risk of deformation or cracking of the casing 100 and minimizing battery cell leakage, the casing 100 in this application embodiment can be made of titanium or steel. Specifically, the casing 100 can be made of TA1, TA4G, TC4, or other high-strength titanium materials modified from titanium, while the explosion-proof valve 200 can be made of pure titanium low-strength materials such as TA1 or TA2. TA1 or TA2 are industrial pure titanium with high titanium content and few impurities. TA4G is a modified TA4 material, further enhancing its strength. TC4 is an α+β type titanium alloy with high strength and good corrosion resistance, which, when used for the casing 100, effectively ensures structural strength. Therefore, by using a titanium or steel shell, the shell 100 has higher strength, and it has the advantages of a high-energy chemical system and lightweight high strength. There is a tendency to use a thinner wall and higher strength shell 100, which helps to adapt to the high expansion force of high energy density cells and improve the reliability of battery cells. At the same time, the molding of the explosion-proof valve 200 is more difficult when using a titanium or steel shell.

[0137] In some of these embodiments, such as Figure 8 and Figure 10 The bending portion 220 may include a first bending portion 221 and a second bending portion 222, which are connected and extend crosswise.

[0138] It should be noted that the first bending portion 221 and the second bending portion 222 are connected to each other at a certain angle and extend in an intersecting manner. For example, the first bending portion 221 can extend in a horizontal direction, and the second bending portion 222 can intersect with it at an angle of 45° or 90° to form a three-dimensional intersecting structure.

[0139] The connection point between the two sub-sections serves as a stress transfer node, deforming collaboratively under pressure. Through a cross-extending layout, multiple stress concentration areas are formed, collectively controlling the opening process of the explosion-proof valve 200. Simultaneously, during pressure relief, they mutually support and share the pressure, reducing the risk of excessive local deformation or rupture of the explosion-proof valve 200.

[0140] In some of these embodiments, such as Figure 8The bending portion 220 may also include a third bending portion 223, which connects the first bending portion 221 and the second bending portion 222.

[0141] The third bend portion 223 serves as an intermediate connecting unit, connecting to the first bend portion 221 and the second bend portion 222 respectively, and can form geometric structures of different shapes. For example, the first bend portion 221 can extend horizontally, the second bend portion 222 can extend vertically, and the third bend portion 223 connects the two at an inclined angle, forming a spatial three-dimensional bend shape. This embodiment does not limit this.

[0142] By including the third bending sub-section 223, when the internal pressure of the battery increases, multiple stress transmission nodes are formed at the connection of the three sub-sections, which can distribute the stress more evenly, reduce the risk of premature failure due to stress concentration, ensure that the explosion-proof valve 200 remains in a complete sealing state before reaching the design pressure relief, and improve the reliability of the battery cell 1100.

[0143] In some of these embodiments, such as Figure 8 The third bend portion 223 can be parallel to the main body portion 210, and the surface away from the main body portion 210 is flush with the housing 100.

[0144] By setting the third bending section 223 parallel to the main body section 210, the overall thickness of the explosion-proof valve 200 is made thinner and does not occupy additional space inside or outside the battery housing 100. Moreover, when the explosion-proof valve 200 is subjected to internal pressure, the parallel structure can evenly distribute the stress to the entire bending section 220, and the gas can be discharged in an orderly manner along the parallel path, reducing the risk of disordered airflow causing damage to other components inside the battery.

[0145] By setting the surface of the valve 210, which is furthest from the main body, to be flush with the housing 100, it helps reduce the entry of external dust and other impurities into the pressure relief port 111, thereby effectively protecting the explosion-proof valve 200 and extending its service life. At the same time, this allows for a smooth transition between the pressure relief port 111 and the outer surface of the housing 100, further optimizing the airflow direction, reducing resistance during gas discharge, and improving pressure relief efficiency.

[0146] In some embodiments, the third bend portion 223 may extend intersectingly with the body portion 210.

[0147] It should be noted that the angle of the intersection of the third bending sub-section 223 and the main body 210 is not limited and can be set according to actual needs. This helps to significantly reduce the gas exhaust velocity and reduce the impact of high-speed airflow on the internal components of the battery. On the other hand, by adjusting the intersection angle and bending state, the airflow can be accurately guided to a safe area, improving the reliability of the battery cell 1100.

[0148] By setting the third bending sub-section 223 to extend intersectingly with the main body 210, the effective deformation length and surface area of ​​the explosion-proof valve 200 are increased within a limited space, thereby improving the pressure relief capacity without increasing the overall size.

[0149] In some embodiments, the bending portion 220 includes a plurality of first bending portions 221 and a plurality of second bending portions 222. Along the extending direction of the body portion 210, the plurality of first bending portions 221 and the plurality of second bending portions 222 are arranged alternately. The first bending portions 221 and the second bending portions 222 connected thereto form a bending group. The bending group includes multiple groups. Along the extending direction of the body portion 210, the multiple bending groups include multiple grooves or multiple protrusions.

[0150] It should be noted that the first bending portion 221 and the second bending portion 222 can both be bent toward the inside of the housing 100, forming a recessed area, such as a groove, on the surface of the main body portion 210 after bending; or, the first bending portion 221 and the second bending portion 222 can both be bent toward the outside of the housing 100, forming a protruding area, such as a protrusion, on the surface of the main body portion 210 after bending.

[0151] During the processing, along the extension direction of the main body 210, the material can be repeatedly processed in the order of first bending part 221, second bending part 222, first bending part 221, and second bending part 222, so that the material is bent alternately in different directions.

[0152] The processing technology is not limited. For example, the bent portion 220 is formed by injection molding. Protrusions or grooves corresponding to the bent portion 220 are processed on the mold surface. Molten material is injected into the mold cavity at a certain rate. After cooling and solidification, the plastic material forms alternating grooves and protrusions on the surface of the main body 210 due to the shape of the cavity. Alternatively, a laser beam can be used to heat a local area to soften the material. Then, an external force is applied by a mechanical device to bend the heated area in a specified direction to form the first bent portion 221 and the second bent portion 222.

[0153] By including multiple first bends 221 and multiple second bends 222, the effective pressure relief area of ​​the explosion-proof valve 200 is effectively increased. When the pressure reaches the threshold, the internal high-pressure gas can be released rapidly from multiple parts simultaneously, improving the pressure relief efficiency. At the same time, the alternating arrangement of grooves or protrusions enhances its resistance to external mechanical impacts and internal pressure fluctuations, extending the service life of the explosion-proof valve 200.

[0154] In some of these embodiments, such as Figure 8Along the extending direction of the main body 210, the bent portion 220 is located within the pressure relief port 111. It can be understood that the bent portion 220 is located within the pressure relief port 111, that is, the bent portion 220 bends towards the inside of the housing 100 relative to the main body 210.

[0155] It should be noted that the pressure relief port 111 is the only controllable channel for the discharge of high-pressure gas inside the battery. The bending part 220 is located inside the pressure relief port 111. The gas can only be discharged by deforming or breaking through the bending part 220, ensuring that the pressure relief process is actively controlled by the bending part 220.

[0156] By positioning the bend 220 within the pressure relief port 111, the pressure relief path can be precisely located, ensuring that when the internal pressure of the battery increases, gas can only be discharged through the pre-set explosion-proof valve 200 structure, reducing the disorderly diffusion of gas within the casing 100, thereby ensuring that high-pressure gas is concentrated and discharged from the pressure relief port 111, improving pressure relief efficiency. Furthermore, it can directly withstand the internal pressure of the battery without requiring additional space on the outside of the casing 100.

[0157] In some of these embodiments, such as Figure 8 and Figure 9 It may also include a connecting segment 230, which is connected to the side of the bent portion 220 away from the body portion 210 along the extending direction of the body portion 210 and is connected to the housing 100.

[0158] The connecting section 230 tightly connects the bending part 220 to the main body 210, which helps to build a stable mechanical transmission channel. When the explosion-proof valve 200 is opened to release pressure, the impact force generated by the internal high-pressure gas on the bending part 220 is transmitted to the housing 100 through the connecting section 230. This effectively reduces the risk of tearing or falling off at the connection between the bending part 220 and the housing 100 due to stress concentration, significantly enhances the overall structural stability of the explosion-proof valve 200, and reduces the risk of failure caused by mechanical stress.

[0159] In some of these embodiments, such as Figure 8 The minimum distance between the upper end face of the explosion-proof valve 200 and the inner surface of the connecting section 230 is d, and d satisfies the condition: 0.2mm≤d≤3mm.

[0160] In some embodiments, the minimum distance d between the upper end face of the explosion-proof valve 200 and the inner surface of the connecting section 230 can be 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.7mm, 1.0mm, 1.5mm, 3mm, or any value between 0.2mm and 3mm. This embodiment does not limit this.

[0161] If d≤0.2mm, the upper end face of the explosion-proof valve 200 and the inner surface of the connecting section 230 are almost in contact. If the gap is too small, the sealing may be affected by the machining error, which will hinder normal pressure relief. If d≥3mm, the gap may allow dust, condensate and other impurities to remain, which may block the pressure relief channel after long-term use.

[0162] Therefore, by setting the distance between the upper end face of the explosion-proof valve 200 and the inner surface of the connecting section 230 between 0.2mm and 3mm, the explosion-proof valve 200 and the inner surface of the connecting section 230 maintain a small gap in the non-pressure relief state, which not only prevents rigid contact wear, but also fills the gap with sealing materials (such as adhesive layer, sealing ring) to form a reliable static seal and prevent external moisture and dust from entering.

[0163] In some of these embodiments, such as Figure 8 The angle between the first bending part 221 and the extension direction of the main body part 210 can be A, and A can satisfy the condition: 10°≤A≤45°.

[0164] In some embodiments, the included angle A between the first bent portion 221 and the main body portion 210 can be set to 10°, 20°, 30°, 35°, 45°, or any value between 10° and 45°. This embodiment does not limit this.

[0165] If the included angle A is less than 10°, the included angle A is too small, and the first bending part 221 is almost parallel to the main body part 210, making it difficult to form an effective stress point and failing to effectively guide and buffer the airflow using the bending structure. If the included angle A is greater than 45°, the included angle A is too large, and the first bending part 221 and the main body part 210 are almost in the opposite direction of the same straight line, reducing the overall stiffness of the bending part 220.

[0166] Therefore, by limiting the range of the angle between the first bending sub-section 221 and the extension direction of the main body 210, and keeping it within a reasonable range, it is ensured that the deformation of the explosion-proof valve 200 under pressure cycling is concentrated in the bending area, reducing the risk of stress diffusion to the main body 210 or the connecting section 230, so that the explosion-proof valve 200 can quickly and stably open to release pressure when the internal pressure of the battery reaches a preset threshold, thereby improving the reliability of the battery cell 1100.

[0167] In some of these embodiments, such as Figure 8 The angle between the second bending part 222 and the extension direction of the main body part 210 can be B, and B can satisfy the condition: 45°≤B≤90°.

[0168] In some embodiments, the included angle B between the second bent portion 222 and the main body portion 210 can be set to 45°, 55°, 65°, 75°, 85°, 90°, or any value between 45° and 90°. This embodiment does not limit this.

[0169] If the included angle B is too small, the second bending sub-section 222 and the main body 210 are nearly parallel, making it difficult to form an effective stress point at the bend. The internal pressure of the battery needs to significantly exceed the design threshold before the bend will crack or deform, resulting in a delay in the opening of the explosion-proof valve 200. If the included angle B is too large, the second bending sub-section 222 and the main body 210 form a large-angle bend, and the structure itself is in a high-stress state. Slight vibration or temperature changes may trigger premature cracking at the bend, posing a risk of accidental pressure leakage.

[0170] Therefore, by limiting the range of the angle between the second bending sub-section 222 and the extension direction of the main body 210, it helps to prevent stress concentration at a single bending point, distribute pressure to multiple areas, and enhance the reliability of the explosion-proof valve 200 under complex loads.

[0171] In some embodiments, the yield strength α of the explosion-proof valve 200 satisfies the condition: 140MPa≤a≤500MPa.

[0172] In some embodiments, the yield strength α of the explosion-proof valve 200 can be 140MPa, 200MPa, 280MPa, 300MPa, 350MPa, 400MPa, 500MPa, or any value between 140MPa and 140MPa. This embodiment does not limit this.

[0173] If the yield strength 'a' of the explosion-proof valve 200 is less than 140 MPa, plastic indentation may occur due to insufficient yield strength, posing a risk of seal failure. If the yield strength 'a' of the explosion-proof valve 200 is greater than 500 MPa, the pressure on the mold during stamping of the explosion-proof valve 200 will be too high, reducing the mold's service life and increasing processing costs. Therefore, setting the yield strength 'a' of the explosion-proof valve 200 between 140 MPa and 500 MPa helps ensure the structural integrity of the housing 100 and enables it to withstand higher mechanical impacts.

[0174] In some embodiments, the yield strength b of the first wall 110 satisfies the condition: 140MPa≤b≤1000MPa.

[0175] In some embodiments, the yield strength b of the first wall 110 can be 140 MPa, 200 MPa, 280 MPa, 300 MPa, 350 MPa, 400 MPa, 500 MPa, 600 MPa, 700 MPa, 800 MPa, 900 MPa, 1000 MPa, or any value between 140 MPa and 1000 MPa. This embodiment does not limit this.

[0176] By setting the yield strength b of the first wall 110 between 140MPa and 1000MPa, on the one hand, the structural strength of the shell 100 is effectively ensured, thereby providing effective support for the explosion-proof valve 200; on the other hand, the strength of the shell 100 is kept within a suitable range, reducing the problem that the shell 100 is too hard as a whole due to excessive strength, and the explosion-proof valve 200 cannot deform and absorb energy well.

[0177] In some embodiments, the tensile strength e of the explosion-proof valve 200 can meet the condition: 240MPa≤e≤600MPa.

[0178] In some embodiments, the tensile strength e of the explosion-proof valve 200 can be 240MPa, 340MPa, 440MPa, 500MPa, 550MPa, 580MPa, 600MPa, or any value between 240MPa and 600MPa. This embodiment does not limit this.

[0179] If the tensile strength e of the explosion-proof valve 200 is less than 240 MPa, its insufficient tensile strength may lead to premature plastic deformation or fracture, resulting in unnecessary pressure relief. If the tensile strength e of the explosion-proof valve 200 is greater than 600 MPa, the excessive strength makes it difficult for the valve to open at the preset pressure threshold, causing continuous pressure accumulation inside the battery. Therefore, by setting the tensile strength e of the explosion-proof valve 200 between 240 MPa and 600 MPa, timely and stable pressure relief can be achieved, effectively preventing continuous pressure rise from damaging the battery. Simultaneously, the appropriate strength ensures that the explosion-proof valve 200 maintains a controllable rupture mode during pressure relief, avoiding the generation of dangerous fragments and minimizing safety risks.

[0180] In some of these embodiments, such as Figure 6 The explosion-proof valve 200 includes a groove 240 provided on the body portion 210, and the groove 240 surrounds the outer periphery of the bent portion 220 in the extending direction of the body portion 210.

[0181] It should be noted that the shape of the notch 240 is not limited. For example, the notch 240 can be a ring-shaped structure that surrounds the outer periphery of the bent portion 220 along the extension direction of the body portion 210, forming a continuous closed ring-shaped line. The notch 240 can also form an annular groove on the surface of the body portion 210; this embodiment does not limit this.

[0182] By setting the notch 240, the notch 240 further weakens the local strength, ensuring that the explosion-proof valve 200 prioritizes the opening of the housing 100 to release pressure when the battery is over-voltage; at the same time, the position of the notch 240 matches the tensile strength, which can make the explosion-proof valve 200 more evenly stressed during the opening process, prolong the effective pressure relief time, and improve the pressure relief efficiency.

[0183] In some embodiments, the Vickers hardness of the explosion-proof valve 200 is c, and the Vickers hardness of the housing 100 is d, where c and d satisfy the condition: c≤d.

[0184] Vickers hardness is an index that measures the hardness of a material by indentation. Its core principle is: a diamond indenter in the shape of a square pyramid with a vertex angle of 136° is pressed vertically into the surface of the material under a certain test force, held for a specified time, and then the test force is removed. The hardness of the material is calculated by measuring the length of the diagonal of the indentation.

[0185] In the stamping design of the explosion-proof valve 200, the explosion-proof valve 200 has a low Vickers hardness. That is, the explosion-proof valve 200 uses a material with a low Vickers hardness, which usually has better plasticity and is easier to undergo plastic deformation during the stamping process, reducing the processing difficulty and helping to form a precise pressure relief structure. The shell 100 bears the internal pressure and external load. A higher Vickers hardness can improve the material's resistance to deformation, which helps to ensure the overall strength and prevent the shell 100 from deforming or breaking.

[0186] Therefore, by setting the Vickers hardness of the explosion-proof valve 200 to be less than or equal to the Vickers hardness of the housing 100, while maintaining the structural strength of the housing 100, it helps to further reduce the stamping difficulty of the explosion-proof valve 200 and improve the stamping effect of the explosion-proof valve 200.

[0187] In some embodiments, the Vickers hardness c of the explosion-proof valve 200 satisfies the condition: 100MPa≤c≤250MPa.

[0188] In some embodiments, the Vickers hardness c of the explosion-proof valve 200 can be 100MPa, 150MPa, 180MPa, 200MPa, 250MPa, or any value between 100MPa and 250MPa. This embodiment does not limit this.

[0189] By setting the Vickers hardness c of the explosion-proof valve 200 between 100MPa and 250MPa, on the one hand, it helps to ensure the basic structural strength of the explosion-proof valve 200 and maintain the morphological stability of the explosion-proof valve 200; on the other hand, it helps to maintain sufficient plasticity to ensure controllable fracture in the event of thermal runaway.

[0190] In some embodiments, the Vickers hardness d of the housing 100 satisfies the condition: 100MPa≤d≤380MPa.

[0191] In some embodiments, the Vickers hardness d of the housing 100 can be 100 MPa, 150 MPa, 180 MPa, 200 MPa, 250 MPa, 300 MPa, 380 MPa, or any value between 100 MPa and 380 MPa. This embodiment does not limit this.

[0192] By setting the Vickers hardness d of the casing 100 between 100MPa and 380MPa, it helps to ensure basic resistance to deformation, while also being able to withstand higher mechanical impacts, thus improving the reliability of the battery cell 1100.

[0193] In some of these embodiments, such as Figure 8 The thickness of the explosion-proof valve 200 can be T, where T meets the condition: 0.05mm≤T≤0.5mm.

[0194] In some embodiments, the thickness T of the explosion-proof valve 200 can be set to 0.05mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, or any value between 0.05mm and 0.5mm, depending on actual needs. This embodiment does not limit this.

[0195] If the thickness T of the explosion-proof valve 200 is ≤0.05mm, the material is prone to premature breakage due to processing errors, vibration, or impact, leading to accidental pressure leakage. If the thickness T of the explosion-proof valve 200 is ≥0.5mm, its tensile strength and yield strength are high, requiring the design pressure to be exceeded before opening, which can easily lead to uncontrolled internal pressure. Therefore, setting the thickness T of the explosion-proof valve 200 between 0.05mm and 0.5mm helps ensure that the material has basic structural strength to resist vibration, impact, and pressure fluctuations under normal operating conditions, thus avoiding accidental pressure leakage.

[0196] In some embodiments, the end cap is thicker than the wall thickness of the housing 120. The end cap can withstand higher mechanical loads and improve the reliability of the battery cell 1100. The housing 120 can be appropriately thinned to help reduce the overall weight of the housing 100 while still maintaining the necessary support function.

[0197] In some of these embodiments, such as Figure 7The thickness of the end cap can be h1, where h1 satisfies the condition: 0.5mm ≤ h1 ≤ 1.5mm. The thickness h1 of the end cap can be set to 0.5mm, 0.8mm, 1.0mm, 1.2mm, 1.5mm, or any value between 0.5mm and 1.5mm, depending on actual needs.

[0198] By setting the thickness h1 of the end cap between 0.5mm and 1.5mm, on the one hand, it helps ensure that the end cap has sufficient mechanical strength, reducing the risk of plastic deformation or cracking of the battery cell 1100 during normal use, providing a stable support base for the explosion-proof valve 200, and reducing the risk of the explosion-proof valve 200 failing due to an excessively thin end cap. On the other hand, it helps control the weight of the housing 100, reducing the excessive increase in the weight of the battery cell 1100.

[0199] In some of these embodiments, such as Figure 7 The wall thickness of the shell 120 is h2, which satisfies the condition: 0.1mm≤h2≤0.4mm. The wall thickness h2 of the shell 120 can be set to 0.1mm, 0.2mm, 0.3mm, 0.4mm or any value between 0.1mm and 0.4mm, depending on actual needs.

[0200] By setting the thickness h2 of the housing 120 between 0.1mm and 0.4mm, on the one hand, it helps to ensure that the housing 120 has sufficient mechanical support to prevent deformation during battery assembly or transportation; on the other hand, it can effectively control the weight of the housing 100.

[0201] In some of these embodiments, such as Figure 8 and Figure 9 The housing 100 may include a first end plate 112, which surrounds the periphery of the pressure relief port 111 and is connected to the connecting section 230.

[0202] The first end plate 112 is tightly connected to the connecting section 230, forming a stable mechanical support structure. When the explosion-proof valve 200 is opened to release pressure, the impact force generated by the high-pressure gas is transmitted to the first end plate 112 through the connecting section 230. Its annular structure can evenly distribute stress, preventing tearing or deformation around the pressure relief port 111 due to stress concentration, thus enhancing the integrity and reliability of the housing 100 during the pressure relief process and improving the reliability of the battery cell 1100.

[0203] In some of these embodiments, such as Figure 5 and Figure 6The battery cell 1100 may include a protective patch 300, and the housing 100 includes a second end plate 113, which is arranged around the outer periphery of the first end plate 112 away from the pressure relief port 111; the protective patch 300 is connected to the second end plate 113 and covers the explosion-proof valve 200.

[0204] The protective patch 300 effectively resists external mechanical impact and friction, protecting key parts of the explosion-proof valve 200 such as the scratches 240 and the bends 220 from damage, ensuring that it can perform its pressure relief function normally when the battery is over-voltage.

[0205] In some embodiments, the material of the housing 100 may include a titanium alloy, the material of the explosion-proof valve 200 may include a titanium alloy, and the Ti content in the explosion-proof valve 200 is greater than or equal to the Ti content in the housing 100.

[0206] It should be noted that the explosion-proof valve 200, as a key component for pressure relief, has a higher Ti content, resulting in higher purity of the titanium alloy and relatively lower impurity element content. This helps reduce material strength and improve plasticity, ensuring the reliable opening of the explosion-proof valve 200 under the preset pressure. The housing 100 primarily bears the structural load-bearing function. Its relatively low Ti content can be strengthened by adding alloying elements to improve the yield strength and hardness of the housing 100, ensuring the structural stability of the housing 100.

[0207] By setting a higher Ti content in the explosion-proof valve 200, the material is closer to the properties of pure titanium, with better plasticity and toughness, but lower strength, making the explosion-proof valve 200 more prone to plastic deformation under impact loads. By setting a lower Ti content in the shell 100, the yield strength and rigidity of the shell 100 can be significantly improved, enabling it to maintain its structural support capacity during impact.

[0208] In some embodiments, the Ti content in the housing 100 can be 80%-99.6%.

[0209] In some embodiments, the Ti content in the casing 100 can be 80%, 85%, 90%, 92%, 94%, 98%, 99.6%, or any value between 80% and 99.6%. This embodiment does not limit this.

[0210] By setting the Ti content in the shell 100 to between 80% and 99.6%, on the one hand, the risk of the shell 100 being prone to fracture under impact load is reduced; on the other hand, it helps to reduce the problem that the shell 100 cannot provide effective support when its strength is too low.

[0211] In some embodiments, the Ti content in the explosion-proof valve 200 can be 90%-99.6%.

[0212] In some embodiments, the Ti content in the explosion-proof valve 200 can be 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99.6%, or any value between 90% and 99.6%. This embodiment does not limit this. By setting the Ti content in the explosion-proof valve 200 to 90%-99.6%, better plasticity and toughness, and lower strength are achieved, making the explosion-proof valve 200 more prone to plastic deformation under impact loads.

[0213] The battery performance of the embodiments and comparative examples was tested below with relevant parameters. The specific values ​​are detailed in Table 1.

[0214] Table 1: Influence of the yield strength of the explosion-proof valve and the yield strength of the shell on the pressure relief effect of the battery cell

[0215]

[0216] As shown in Table 1, the yield strength of the explosion-proof valve 200 and the housing 100 has a certain impact on the pressure relief effect. In Examples 1, 2 and 3, the yield strength a of the explosion-proof valve 200 is less than the yield strength b of the housing 100. The explosion-proof valve 200 opens first to release pressure in a directional manner. In the comparative example, if the yield strength of the explosion-proof valve 200 is greater than the yield strength of the housing 100, that is, the yield strength of the housing 100 is smaller, the housing 100 may break first if the internal pressure of the battery is too high, and the housing 100 opens first, resulting in the pressure relief effect being out of control.

[0217] Furthermore, combining Embodiments 2 and 3, even if the yield strength of both is increased simultaneously, the pressure relief effect remains controllable as long as the yield strength of the explosion-proof valve 200 is less than that of the housing 100. It should be noted that in actual design, calculations based on the pressure threshold are required to ensure that the explosion-proof valve 200 is triggered at a predetermined pressure.

[0218] Table 2: Influence of the tensile strength of the explosion-proof valve and the tensile strength of the shell on the molding effect of the explosion-proof valve

[0219]

[0220] As shown in Table 2, the tensile strength of the explosion-proof valve 200 has a certain impact on the forming effect of the explosion-proof valve 200. In Examples 1, 2 and 3, the tensile strength e of the explosion-proof valve 200 is less than the tensile strength f of the shell. Thus, the explosion-proof valve 200 with a smaller tensile strength has a higher forming effect and will not damage the stamping die. At the same time, in Examples 1, 2 and 3, the tensile strength of the shell 100 can be set to be larger, which helps to ensure the mechanical strength of the shell 100 and improve its ability to withstand mechanical loads and internal pressure.

[0221] Referring again to Table 2, in the comparative example, since the tensile strength e of the explosion-proof valve 200 is greater than the tensile strength f of the shell, on the one hand, the tensile strength of the explosion-proof valve 200 is too high, and the mold may be damaged due to excessive force during the stamping process; on the other hand, the tensile strength of the shell 100 is too low, which affects the mechanical strength and structural stability of the shell 100.

[0222] The battery cell 1100 provided in this embodiment includes a housing 100. The housing 100 adopts a split structure design, consisting of a body 120 and an end cap. The housing 100 includes a first wall 110 and an explosion-proof valve 200. The end cap serves as the first wall 110 and is tightly connected to the body 120. The first wall 110 has a pressure relief port 111, and the explosion-proof valve 200 is disposed at the pressure relief port 111. The explosion-proof valve 200 may include a body portion 210 and at least one bent portion 220. The body portion 210 is connected to the bent portion 220, and at least a portion of the bent portion 220 protrudes from the body portion 210. In this embodiment, the yield strength of at least a portion of the explosion-proof valve 200 is less than the yield strength of the housing 100. The yield strength 'a' of the explosion-proof valve 200 satisfies the condition: 140MPa≤a≤500MPa, and the yield strength 'b' of the housing 100 satisfies the condition: 140MPa≤b≤1000MPa. The housing 100 is made of titanium or steel. Specifically, the explosion-proof valve 200 can be a structural component made of TA1 or TA2, and the housing 100 can be a structural component made of any of TA1, TA4G, or TC4. The tensile strength e of the explosion-proof valve 200 satisfies the condition: 240MPa≤e≤1000MPa, and the tensile strength f of the first wall 110 satisfies the condition: 240MPa≤e≤1000MPa.

[0223] During the manufacturing process of the battery cell 1100 provided in this application embodiment, by providing a body portion 210 and at least one bent portion 220, the bent portion 220 can stably support the body portion 210 during normal operation, reducing the abnormal opening of the explosion-proof valve 200 due to internal pressure. By providing the bent portion 220 protruding from the body portion 210, the bent portion 220 can effectively disperse the impact force generated during the pressure relief process, making the pressure relief process more stable. Furthermore, the extension direction of the bent portion 220 provides a clear guiding path for the pressure relief process. When the internal pressure of the battery increases and pressure relief is required, the gas can flow more orderly towards the pressure relief port 111 along the extension direction of the bent portion 220, reducing chaos and disorder during the pressure relief process, helping to improve pressure relief efficiency and enhance the reliability of the battery cell 1100. By setting the yield strength of the explosion-proof valve 200 to be lower than that of the housing 100, when the internal pressure of the battery increases and pressure relief is required, the weak area of ​​the explosion-proof valve 200 will preferentially undergo plastic deformation or fracture, thereby opening the pressure relief port 111 to release the internal pressure. Simultaneously, this helps reduce the stamping difficulty of the bending portion 220 and improves the stamping effect of the explosion-proof valve 200. By setting the tensile strength of both the explosion-proof valve 200 and the first wall 110 within the range of 240MPa to 1000MPa, this application increases the tensile strength of the housing 100. The higher tensile strength of the housing 100 compared to aluminum-cased explosion-proof valves in related technologies helps to adapt to the high expansion force of high-energy-density cells, thereby withstanding the internal expansion force generated by the high-energy-density cells during charging and discharging, reducing the risk of deformation or breakage of the housing 100, and improving the reliability of the battery cells. However, with higher tensile strength, the molding difficulty of the explosion-proof valve is also higher. By using a titanium or steel shell, the shell 100 has higher strength. It has the advantages of a high-energy chemical system and lightweight high strength. There is a tendency to use a thinner wall and higher strength shell 100, which helps to adapt to the high expansion force of high energy density cells and improve the reliability of battery cells. At the same time, the molding of the explosion-proof valve is more difficult when using a titanium or steel shell.

[0224] Please see Figure 2 This application also provides a battery device, including a housing and a battery cell 1100, wherein the battery cell 1100 is housed in the housing.

[0225] When the battery cell 1100 provided in this embodiment is in use, the explosion-proof valve 200 includes a body portion 210 and at least one bent portion 220. During normal operation, the bent portion 220 provides stable support to the body portion 210, reducing the risk of abnormal opening of the explosion-proof valve 200 due to internal pressure. When the internal pressure of the battery cell 1100 increases and pressure relief is required, the bent portion 220 reduces stress concentration around the pressure relief port 111 that may occur during the pressure relief process, thereby reducing the risk of casing 100 rupture due to stress concentration. By setting the bend 220 to protrude from the body 210, the bend 220 can effectively disperse the impact force generated during the pressure relief process of the battery cell 1100, making the pressure relief process more stable. In addition, the extension direction of the bend 220 provides a clear guiding path for the pressure relief process. When the internal pressure of the battery increases and pressure relief is required, the gas can flow more orderly to the pressure relief port 111 along the extension direction of the bend 220, reducing chaos and disorder during the pressure relief process, which helps to improve the pressure relief efficiency and enhance the reliability of the battery cell 1100. By setting the yield strength of the explosion-proof valve 200 to be less than that of the shell 100, when the internal pressure of the battery increases and pressure relief is required, the weak area of ​​the explosion-proof valve 200 will preferentially undergo plastic deformation or fracture, thereby opening the pressure relief port 111 to release the internal pressure. At the same time, it helps to reduce the stamping difficulty of the bend 220 and improve the stamping effect of the explosion-proof valve 200.

[0226] Please see Figure 1 This application provides an electrical device, including a battery device from any of the above embodiments, which is used to provide electrical energy to the electrical device.

[0227] When the electrical device provided in this application embodiment is in use, the battery device composed of the battery cells 1100 provided in this application embodiment provides electrical energy to the electrical device. The explosion-proof valve 200 includes a body portion 210 and at least one bent portion 220. When the battery cell 1100 is working normally, the bent portion 220 can stably support the body portion 210, reducing the abnormal opening of the explosion-proof valve 200 due to the influence of internal pressure. When the internal pressure of the battery cell 1100 increases and needs to be released, the bent portion 220 can reduce the stress concentration around the pressure relief port 111 that may occur during the pressure relief process, thereby reducing the risk of shell 100 rupture due to stress concentration. By setting the bend 220 to protrude from the body 210, the bend 220 can effectively disperse the impact force generated during the pressure relief process of the battery cell 1100, making the pressure relief process more stable. In addition, the extension direction of the bend 220 provides a clear guiding path for the pressure relief process. When the internal pressure of the battery increases and pressure relief is required, the gas can flow more orderly to the pressure relief port 111 along the extension direction of the bend 220, reducing chaos and disorder during the pressure relief process, which helps to improve the pressure relief efficiency and enhance the reliability of the battery cell 1100. By setting the yield strength of the explosion-proof valve 200 to be less than that of the shell 100, when the internal pressure of the battery increases and pressure relief is required, the weak area of ​​the explosion-proof valve 200 will preferentially undergo plastic deformation or fracture, thereby opening the pressure relief port 111 to release the internal pressure. At the same time, it helps to reduce the stamping difficulty of the bend 220 and improve the stamping effect of the explosion-proof valve 200.

[0228] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, include: Housing (100), the housing (100) comprising: The first wall (110) has a pressure relief port (111) and the tensile strength f of the first wall (110) satisfies the condition: 240MPa≤e≤1000MPa; An explosion-proof valve (200) is disposed at the pressure relief port (111). The tensile strength e of the explosion-proof valve (200) satisfies the condition: 240MPa≤e≤1000MPa. The explosion-proof valve (200) includes: The main body (210) is arranged parallel to the first wall (110); At least one bend (220) is connected to the body portion (210), and at least a portion of the bend (220) protrudes from the body portion (210) along the thickness direction of the body portion (210); The yield strength a of at least part of the explosion-proof valve (200) is less than the yield strength b of the first wall (110).

2. The battery cell according to claim 1, characterized in that, The bending portion (220) includes a first bending sub-portion (221) and a second bending sub-portion (222), which are connected and extend in a cross direction.

3. The battery cell according to claim 2, characterized in that, The bending portion (220) further includes a third bending sub-portion (223), which connects the first bending sub-portion (221) and the second bending portion (222).

4. The battery cell according to claim 3, characterized in that, The third bent portion (223) is parallel to the main body portion (210), and the surface away from the main body portion (210) is flush with the housing (100).

5. The battery cell according to claim 3, characterized in that, The third bending sub-section (223) extends intersectingly with the main body section (210).

6. The battery cell according to claim 1, characterized in that, The bending portion (220) includes a plurality of first bending sub-parts (221) and a plurality of second bending sub-parts (222), which are arranged alternately along the extension direction of the main body portion (210).

7. The battery cell according to claim 6, characterized in that, The first bending sub-section (221) and the second bending sub-section (222) connected thereto together form a bending group; The bending group includes multiple groups along the extension direction of the body portion (210), and the multiple bending groups include multiple grooves or multiple protrusions.

8. The battery cell according to any one of claims 1-7, characterized in that, Along the extending direction of the main body (210), the bent portion (220) is located inside the pressure relief port (111).

9. The battery cell according to any one of claims 1-7, characterized in that, It also includes a connecting segment (230) extending along the extension direction of the body portion (210), the connecting segment (230) being connected to the side of the bent portion (220) away from the body portion (210) and connected to the housing (100).

10. The battery cell according to claim 9, characterized in that, The minimum distance between the upper end face of the explosion-proof valve (200) and the inner surface of the connecting section (230) is d, and d satisfies the following condition: 0.2mm≤d≤3mm.

11. The battery cell according to any one of claims 2-7, characterized in that, The angle between the first bent portion (221) and the extending direction of the main body portion (210) is A, and A satisfies the condition: 10°≤A≤45°。 12. The battery cell according to any one of claims 2-7, characterized in that, The angle between the second bent portion (222) and the extending direction of the main body portion (210) is B, and B satisfies the condition: 45°≤B≤90。 13. The battery cell according to any one of claims 1-7, characterized in that, The yield strength α of the explosion-proof valve (200) satisfies the following condition: 140MPa≤a≤500MPa.

14. The battery cell according to any one of claims 1-7, characterized in that, The yield strength b of the first wall (110) satisfies the following condition: 140MPa≤b≤1000MPa.

15. The battery cell according to any one of claims 1-7, characterized in that, The tensile strength e of the explosion-proof valve (200) meets the following condition: 240MPa≤e≤600MPa.

16. The battery cell according to any one of claims 1-7, characterized in that, The explosion-proof valve (200) includes a groove (240) which is provided on the body part (210) and surrounds the outer periphery of the bent part (220) along the extending direction of the body part (210).

17. The battery cell according to any one of claims 1-7, characterized in that, The Vickers hardness of the explosion-proof valve (200) is c, and the Vickers hardness of the first wall (110) is d. The c and the d satisfy the following condition: c≤d.

18. The battery cell according to claim 17, characterized in that, The Vickers hardness c of the explosion-proof valve (200) meets the following condition: 100MPa≤c≤250MPa.

19. The battery cell according to claim 17, characterized in that, The Vickers hardness d of the first wall (110) satisfies the following condition: 100MPa≤d≤380MPa.

20. The battery cell according to any one of claims 1-7, characterized in that, The thickness of the explosion-proof valve (200) is T, and T satisfies the following condition: 0.05mm≤T≤0.5mm.

21. The battery cell according to any one of claims 1-7, characterized in that, The housing (100) includes: The shell (120) has an opening in its structure; An end cap covers the opening and is configured with the pressure relief port (111), the end cap serving as the first wall (110).

22. The battery cell according to claim 21, characterized in that, The thickness of the end cap is greater than the wall thickness of the shell (120).

23. The battery cell according to claim 22, characterized in that, The thickness of the end cap is h1, and h1 satisfies the following condition: 0.5mm≤h1≤1.5mm; The wall thickness of the shell (120) is h2, and h2 satisfies the following condition: 0.1mm≤h2≤0.4mm.

24. The battery cell according to claim 9, characterized in that, The housing (100) includes a first end plate (112) which surrounds the periphery of the pressure relief port (111) and is connected to the connecting section (230).

25. The battery cell according to claim 24, characterized in that, The battery cell includes a protective patch (300). The housing (100) includes a second end plate (113), which is circumferentially disposed around the first end plate (112) away from the pressure relief port (111); The protective patch (300) is connected to the second end plate (113) and covers the explosion-proof valve (200).

26. The battery cell according to any one of claims 1-7, characterized in that, The housing (100) may be a titanium housing or a steel housing.

27. The battery cell according to claim 26, characterized in that, The housing (100) is a structural component made of any one of TA1, TA4G or TC4.

28. The battery cell according to claim 26, characterized in that, The explosion-proof valve (200) is a structural component made of TA1 or TA2.

29. The battery cell according to any one of claims 1-7, characterized in that, The battery is a prismatic battery.

30. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1-29.

31. An electrical device, characterized in that, Includes the battery device of claim 30, the battery device being used to provide electrical energy.

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