Battery cell, battery apparatus, and electric apparatus

Abstract

A battery cell (100), a battery apparatus (200), and an electric apparatus (300). The battery cell comprises: a housing (10) provided with a first wall (10a); an electrode assembly (20) accommodated within the housing (10); a pressure relief mechanism (30) disposed on the first wall (10a), wherein a weak portion (31) is configured to rupture upon an internal pressure of the housing (10) reaching a threshold value, a body portion (32) is configured to rotate or disengage relative to the first wall (10a) when the weak portion (31) ruptures, vent holes (41) are in communication with an interior and an exterior of the housing (10), and the vent holes (41) are at least partially disposed on the body portion (32).

Description

Battery cells, battery packs, and electrical devices

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese Patent Application No. 202510205766.1, filed on February 24, 2025, entitled “Battery Cell, Battery Device and Electrical Device”. Technical Field

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

[0004] In related technologies, during the cycle of battery cells, a certain amount of gas is generated inside the battery cell, which causes the internal pressure to rise. It is necessary to set up an exhaust structure to ensure that the internal pressure of the battery cell remains stable. At the same time, a venting structure is also required to open the pressure relief when the internal pressure of the battery cell is too high. This makes the structure of the battery cell relatively complex, the arrangement of the exhaust structure and the pressure relief mechanism difficult, and the exhaust structure and the venting structure can affect each other.

[0005] Application content

[0006] This application aims to at least solve one of the technical problems existing in the prior art. To this end, one object of this application is to provide a battery cell, a battery device, and an electrical device, wherein the battery cell can simultaneously achieve gas generation and venting as well as pressure resistance and safety.

[0007] This application provides a battery cell, including: a housing, an electrode assembly, a pressure relief mechanism, and an exhaust mechanism. The housing has a first wall; the electrode assembly is housed within the housing; the pressure relief mechanism is disposed on the first wall and includes a weak portion and a main body portion. The weak portion is configured to be destroyed when the pressure inside the housing reaches a threshold, and the main body portion is configured to rotate or detach relative to the first wall when the weak portion is destroyed; the exhaust mechanism is disposed on the first wall and includes an exhaust port communicating with the interior and exterior of the housing, with at least a portion of the exhaust port disposed on the main body portion.

[0008] According to the battery cell of this application embodiment, on the one hand, the exhaust mechanism and the pressure relief mechanism are integrated (i.e., a composite exhaust and pressure relief mechanism), which has lower requirements for the space size of the first wall and is easier to set up; on the other hand, the exhaust mechanism and the pressure relief mechanism can be linked to realize exhaust in normal working mode and release in abnormal conditions, and can reduce the impact of uneven pressure distribution and pressure error in the accommodating cavity on the valve opening of the pressure relief mechanism, thereby improving safety and reliability.

[0009] According to some embodiments of this application, the weak part includes: a first weak part, the main body being connected to the first wall, and the first weak part being provided inside the main body.

[0010] According to some embodiments of this application, at least part of the vent is located inside the body portion, and the weak portion is connected to the vent, or the weak portion is spaced apart from the vent.

[0011] According to some embodiments of this application, the first weak portion is annular, the first weak portion surrounds the vent hole, and / or the vent hole is located outside the surrounding area of ​​the first weak portion.

[0012] According to some embodiments of this application, a first weak portion is disposed around one or more vent holes.

[0013] According to some embodiments of this application, the two ends of the first weak portion are respectively connected to two vent holes.

[0014] According to some embodiments of this application, the two ends of the first weak portion are connected to two adjacent vent holes.

[0015] According to some embodiments of this application, one end of the first weak portion is connected to the vent hole, and the other end of the first weak portion extends toward the connection area between the body portion and the first wall.

[0016] According to some embodiments of this application, the weak portion further includes: a second weak portion, wherein the connection area between the body portion and the first wall is formed as the second weak portion.

[0017] According to some embodiments of this application, the vent is disposed within the body portion, and / or the vent is formed in the connection area between the body portion and the first wall.

[0018] According to some embodiments of this application, the vent hole located in the body portion is spaced apart from the second weak portion, and the vent hole located in the connection area between the body portion and the first wall is connected to the second weak portion.

[0019] According to some embodiments of this application, the weak point is constructed as any one of a weld, a local break, or a notch.

[0020] According to some embodiments of this application, the weak part is constructed as a weld, and the weld penetration depth is 0.3 mm to 0.5 mm.

[0021] According to some embodiments of this application, there are multiple vent holes, and the number of vent holes is 3 to 10.

[0022] According to some embodiments of this application, the number of vent holes is 4 to 5.

[0023] According to some embodiments of this application, there are multiple vent holes, and the total vent area of ​​the multiple vent holes is S1. When the weak part is damaged, it rotates or detaches relative to the first wall to define the vent area located on the first wall. The area of ​​the vent area is S2, and satisfies: 0 < S1 / S2 < 0.6.

[0024] According to some embodiments of this application, the outer shell is constructed as a cylinder, the outer shell includes an end cap and a housing, the end cap defines a first wall, and the area of ​​the first wall is S3, and satisfies: 0 < S2 / S3 < 0.3.

[0025] According to some embodiments of this application, the outer shell is constructed as a prism, the first wall is defined by any surface of the prism, the area of ​​the first wall is S4, and satisfies: 0 < S2 / S4 < 0.1.

[0026] According to some embodiments of this application, the venting mechanism includes: a waterproof and breathable membrane disposed on the side of the first wall facing the electrode assembly, and the orthographic projection contour of each vent hole facing the electrode assembly falls within the orthographic projection contour of the waterproof and breathable membrane facing the electrode assembly.

[0027] According to some embodiments of this application, the orthographic projection profile of the waterproof and breathable membrane toward the electrode assembly is spaced apart from the orthographic projection profile of the weak portion toward the electrode assembly.

[0028] According to some embodiments of this application, the pressure relief mechanism is integrally formed with the first wall, or the pressure relief mechanism is assembled on the first wall.

[0029] According to some embodiments of this application, the battery cell is configured as an alkali metal battery.

[0030] According to some embodiments of this application, the electrode assembly includes a negative electrode sheet, the negative electrode sheet includes a negative current collector and an active material layer disposed on at least one side of the negative current collector, the active material layer including an elemental active metal.

[0031] According to some embodiments of this application, the active metal element includes at least one of lithium, sodium, potassium, zinc, or aluminum.

[0032] According to some embodiments of this application, the housing contains an electrolyte, the electrode assembly is immersed in the electrolyte, the electrolyte includes a solvent, and the solvent is configured as at least one of an ether solvent or an ester solvent.

[0033] According to some embodiments of this application, the ether solvent includes at least one of 1,2-dimethoxypropane, dimethoxymethane, ethylene glycol dimethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, pentaethylene glycol dimethyl ether, polyethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol diethyl ether, triethylene glycol diethyl ether, tetraethylene glycol diethyl ether, pentaethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dibutyl ether, or 1,3-dioxane.

[0034] According to some embodiments of this application, a gas storage structure is provided inside the outer casing, and at least a portion of the initial structure is a hydrogen storage metal, including zirconium alloys, magnesium alloys, titanium alloys, vanadium alloys, or La. x Ni y M z At least one of the following, wherein M includes at least one of Zr, Mn, Mg, Zn, Al, Ti, Fe, Cu, Co, Y, Ca or Bi, 0 < x ≤ 2, 0 ≤ y ≤ 7, 0 ≤ z ≤ 3.

[0035] According to some embodiments of this application, M includes at least one of Al, Mn, Mg, Fe, Y or Bi, and 0.3≤x≤1, 1≤y≤5, 0≤z≤1;

[0036] Titanium alloys include at least one of TiNi, Ti2Ni, TiFe, or TiMn2;

[0037] Magnesium alloys include at least one of Mg2Ni, Mg2Cu, Mg2Co, Mg2Al, Mg2Cr, or Mg2Te;

[0038] Zirconium alloys include at least one of ZrV2, ZrCr2, or ZrMn2;

[0039] Vanadium alloys include V3TiNi 0.56 M1 m m = 0.046-0.24, M1 includes at least one of Al, Si, Fe, Cu or Zr.

[0040] According to some embodiments of this application, hydrogen storage metals include LaNi. 3.5 M2 x1 M3 y1 M4 z1 Where x1 is 0.2-0.6, y1 is 0-1, z1 is 0.3-0.9, x1+y1+z1=1.5, M2 includes at least one of Mn or Fe, M3 includes at least one of Zr, Ti or Y, and M4 includes at least one of Al, Mg, Ca or Bi.

[0041] According to some embodiments of this application, hydrogen storage metals include La. 0.5 Ni 4.5 Y 0.5 LaNi 3.5 Mn 0.2 YBi 0.3 LaNi 3.5 Mn 0.6 Y 0.4 Bi 0.5 LaNi 3.5 Mn 0.2 Y 0.4 Bi 0.9 LaTi 3.5 Fe 0.4 Zr 0.5 Bi 0.6 LaTi 3.5 Fe 0.4 Zr 0.5 Mg 0.6 LaNi 4.26 Al 0.08 Mg 0.16 Or La 0.43 Y 0.57 Ni 4.5 Al 0.08 Mn 0.3 At least one of them.

[0042] This application proposes a battery device, comprising: the battery cell described in the above embodiments.

[0043] This application provides an electrical device, including the battery device described in the above embodiments.

[0044] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0045] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0046] Figure 1 is a schematic diagram of an electrical device according to an embodiment of this application;

[0047] Figure 2 is a schematic diagram of a battery device according to an embodiment of this application;

[0048] Figure 3 is a schematic diagram of a battery cell according to an embodiment of this application;

[0049] Figure 4 is another schematic diagram of a battery cell according to an embodiment of this application;

[0050] Figure 5 is a schematic diagram of the end cap according to an embodiment of this application;

[0051] Figure 6 is an exploded view of the end cap according to an embodiment of this application;

[0052] Figure 7 is a top view of the end cap of the first wall body according to an embodiment of this application;

[0053] Figure 8 is a cross-sectional view of line AA in Figure 7;

[0054] Figure 9 is a partial enlarged schematic diagram of area B circled in Figure 8;

[0055] Figure 10 is a schematic diagram of the pressure relief mechanism and the exhaust mechanism according to the first embodiment of this application;

[0056] Figure 11 is a schematic diagram of the pressure relief mechanism and the exhaust mechanism according to the second embodiment of this application;

[0057] Figure 12 is a schematic diagram of the pressure relief mechanism and the exhaust mechanism according to the third embodiment of this application;

[0058] Figure 13 is a schematic diagram of the pressure relief mechanism and the exhaust mechanism according to the fourth embodiment of this application;

[0059] Figure 14 is a schematic diagram of the pressure relief mechanism and the exhaust mechanism according to the fifth embodiment of this application;

[0060] Figure 15 is a schematic diagram of the pressure relief mechanism and the exhaust mechanism according to the sixth embodiment of this application;

[0061] Figure 16 is a pressure-hydrogen content curve of the hydrogen storage alloy prepared in Example 1 of this application;

[0062] Figure 17 is an ion-polished cross-sectional morphology diagram of the hydrogen storage alloy sheet prepared in Example 1 of this application;

[0063] Figure 18 is an internal pressure-time curve of the battery of Embodiment 1 and Comparative Example 1 of this application. Detailed Implementation

[0064] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0065] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., 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 this application and simplifying the description, and do not 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 this application.

[0066] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Furthermore, in the description of this application, unless otherwise stated, "multiple" means two or more.

[0067] A single battery cell can be a rechargeable battery. A rechargeable battery is a battery cell that can be recharged after it has been discharged, allowing the active materials to be activated and the cell to continue to be used.

[0068] The battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0069] The battery device mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which may form a battery array, and the multiple battery cells may be connected in series, parallel, or in a mixed configuration via a busbar.

[0070] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells, such as forming a battery array.

[0071] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form an independent module. As another example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0072] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cell assemblies housed within the housing.

[0073] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0074] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0075] As an example, the enclosure may include a first enclosure and a second enclosure. The first enclosure and the second enclosure are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first enclosure may be a top cover or a bottom plate.

[0076] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0077] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0078] The technical solutions described in the embodiments of this application are applicable to battery devices and electrical equipment using battery devices.

[0079] Electrical equipment can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the above-mentioned electrical equipment.

[0080] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0081] Please refer to Figure 1, which is a schematic diagram of the structure of a vehicle provided in some embodiments of this application. A battery device 200 is installed inside the vehicle, and the battery device 200 can be located at the bottom, front, or rear of the vehicle. The battery device 200 can be used to power the vehicle; for example, the battery device 200 can serve as the vehicle's operating power source.

[0082] The vehicle may also include a controller 500 and a motor 400. The controller 500 controls the battery device 200 to supply power to the motor 400, which serves as a load, for example, for the power needs of the vehicle during starting, navigation and driving.

[0083] In some embodiments of this application, the battery device 200 can not only serve as the operating power source for the vehicle, but also as the driving power source for the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0084] Please refer to Figure 2, which is an exploded view of a battery device 200 provided in some embodiments of this application. The battery device 200 includes a housing 600 for accommodating individual battery cells 100.

[0085] The housing 600 is a component that houses the individual battery cells 100. The housing 600 provides placement space for multiple battery cells 100 and can adopt various structures. In some embodiments, the housing 600 may include a tray and a cover, which overlap to define a placement space for accommodating the battery cells 100. The tray and cover can be of various shapes, such as cuboids, cylinders, etc. The tray can be a hollow structure open on one side, and the cover can also be a hollow structure open on one side, with the open side of the cover overlapping the open side of the tray, thus forming a housing 600 with placement space. Alternatively, the tray can be a hollow structure open on one side, and the cover can be a plate-like structure, with the cover overlapping the open side of the tray, thus forming a housing 600 with placement space. As an example, the battery cell 100 can be a cylindrical battery cell 100, a prismatic battery cell 100, or a battery cell 100 of other shapes (such as a pouch battery cell 100), and this application does not impose any particular limitations.

[0086] In the battery device 200, there can be one or more battery cells 100. If there are multiple battery cells 100, they can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 100 are connected in both series and parallel. Alternatively, multiple battery cells 100 can be first connected in series, parallel, or in a mixed manner to form a battery module, and then multiple battery modules can be connected in series, parallel, or in a mixed manner to form a whole, which is then housed within the housing 600. Another option is that all battery cells 100 can be directly connected in series, parallel, or in a mixed manner, and then the whole consisting of all battery cells 100 is housed within the housing 600.

[0087] The battery cell 100 serves as the smallest energy unit of the battery device 200. The battery device 200 includes multiple battery cells 100. Each battery cell 100 includes a housing 10, an end cap 12, and an electrode assembly 20 disposed within the housing 10.

[0088] As shown in Figures 3 and 4, in some embodiments, the battery cell 100 may include: a housing 11, an end cap 12, and an electrode assembly 20. The housing 11 is used to define an accommodating space with an installation opening. The housing 11 may be a pouch structure that wraps around the electrode assembly 20 of a pouch battery, or it may be constructed as a hard shell structure in which the electrode assembly 20 is disposed.

[0089] For example, the housing 11 may include a base plate and a side plate. The side plate surrounds the periphery of the base plate and defines an accommodating space with a mounting opening. The electrode assembly 20 and other functional components may be disposed in the accommodating space. The end cap 12 covers the mounting opening of the housing 11 to isolate the internal environment of the battery cell 100 from the external environment. The shape of the end cap 12 is adapted to the shape of the housing 11. The end cap 12 may be supported by a material with a certain hardness and strength (such as aluminum alloy or carbon fiber plate). The end cap 12 can effectively protect the safety and reliability of the internal components of the housing 11 during compression and collision.

[0090] In some embodiments, the end cap 12 or the housing 11 may also be provided with a pressure relief mechanism 30 for releasing internal pressure when the internal pressure or temperature of the battery cell 100 reaches a threshold. The end cap 12 can 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 element (e.g., lower plastic 121) may also be provided on the inner side of the end cap 12. The insulating element can be used to isolate the electrical connection components within the housing 11 from the end cap 12 to reduce the risk of short circuits. For example, the insulating element can be plastic, rubber, etc., and an insulating sheet can also be provided between the electrode assembly 20 and the housing 11 to achieve insulation protection.

[0091] The housing 11 is a component used to cooperate with the end cap 12 to form the internal environment of the battery cell 100, wherein the formed internal environment can accommodate the electrode assembly 20, electrolyte, and other components. The housing 11 and the end cap 12 can be independent components. A mounting opening can be provided on the housing 11, and the end cap 12 closes the opening at the mounting opening to form the internal environment of the battery cell 100. The housing 11 can have various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 11 can be determined according to the specific shape and size of the electrode assembly 20. The material of the housing 11 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose any special limitations on this.

[0092] Electrode terminals 122 may be further provided on the end cap 12 or the housing 11. The electrode assembly 20 is the component in the battery cell 100 where the electrochemical reaction occurs. The housing 11 may contain one or more electrode assemblies 20. The electrode assembly 20 is mainly formed by winding or stacking positive and negative electrode sheets, and a separator is usually provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets with active material constitute the main body of the electrode assembly 20, and the portions of the positive and negative electrode sheets without active material each constitute a tab. The positive and negative tabs may be located together at one end of the main body or at opposite ends of the main body. During the charging and discharging process of the battery device 200, the positive and negative active materials react with the electrolyte, and the tabs connect to the electrode terminals 122 to form a current loop.

[0093] In related technologies, during the cycling and storage of battery cell 100, the gas produced inside battery cell 100 will accumulate inside the casing 11, causing the internal pressure of casing 11 to rise. Especially for some battery cells 100 with a large gas production (such as alkali metal batteries), the gas will accumulate rapidly in a short period of time, compressing the internal residual space of battery cell 100, and even causing the gas to be unable to be released and directly triggering the explosion-proof valve.

[0094] In order to release the gas generated inside the battery cell 100 in a timely manner, an exhaust mechanism 40 is required to exhaust the gas. At the same time, in order to improve the safety of the battery cell 100, a pressure relief mechanism 30 is also required to be installed on the battery cell 100 so that the pressure relief mechanism 30 can be opened to release pressure when the internal pressure exceeds the threshold.

[0095] However, the pressure relief mechanism 30 and the exhaust mechanism 40 are both integrated on the housing 11 and end cap 12 of the battery cell 100. The space on the end cap 12 and housing 11 is limited, which makes the arrangement difficult. In addition, there is no linkage between the exhaust mechanism 40 and the pressure relief mechanism 30. The exhaust of the exhaust mechanism 40 may affect the pressure relief of the pressure relief mechanism 30, such as the valve not opening in time or opening the valve prematurely.

[0096] Based on this, this application proposes a battery cell 100, which provides a pressure relief mechanism 30 and an exhaust mechanism 40 on the outer casing 10 (i.e., end cap 12 or housing 11). The exhaust mechanism 40 can be used to discharge the gas generated inside the battery cell 100. The pressure relief mechanism 30 can detach from the outer casing 10 or flip relative to the outer casing 10 when the internal pressure of the battery cell 100 exceeds the pressure threshold, so as to achieve pressure relief. The exhaust port 41 is at least partially provided in the body part 32 of the pressure relief mechanism 30, that is, the exhaust port 41 can realize gas generation and exhaust. The pressure relief mechanism 30 can be further opened when the internal pressure of the battery cell 100 rises to above the threshold, so as to realize the compound linkage of the exhaust mechanism 40 and the pressure relief mechanism 30. When the pressure fails to reach the valve opening threshold, gas generation and exhaust are performed. When the pressure reaches the valve opening threshold, the valve is opened in time to release the gas. This can realize the integration of the pressure relief mechanism 30 and the exhaust mechanism 40, and also reduce the difficulty of arrangement.

[0097] The battery cell 100, battery device 200, and power consumption device 300 according to embodiments of this application are described below with reference to Figures 1-18.

[0098] In a first aspect, as shown in Figures 3 and 4, this application provides a battery cell 100, including: a housing 10, an electrode assembly 20, a pressure relief mechanism 30, and an exhaust mechanism 40.

[0099] The housing 10 has a first wall 10a; the electrode assembly 20 is housed within the housing 10; a pressure relief mechanism 30 is disposed on the first wall 10a, the pressure relief mechanism 30 includes a weak portion 31 and a body portion 32, the weak portion 31 is configured to be destroyed when the pressure inside the housing 10 reaches a threshold, and the body portion 32 is configured to rotate or disengage relative to the first wall 10a when the weak portion 31 is destroyed; an exhaust mechanism 40 is disposed on the first wall 10a, the exhaust mechanism 40 includes an exhaust port 41, the exhaust port 41 communicates with the interior and exterior of the housing 10, and at least a portion of the exhaust port 41 is disposed on the body portion 32.

[0100] It is understood that in an embodiment where the battery cell 100 is constructed as a prismatic battery, the battery cell 100 may include a plurality of opposing walls, at least one of which is formed as a first wall 10a, and the first wall 10a is provided with a pressure relief mechanism 30 and an exhaust mechanism 40. In an embodiment where the battery cell 100 is constructed as a cylindrical battery, the battery cell 100 may include two opposing walls and a side wall, at least one of the side wall or opposing walls being formed as a first wall 10a, and the first wall 10a is provided with a pressure relief mechanism 30 and an exhaust mechanism 40.

[0101] As shown in Figures 5 and 6, the outer casing 10 has a first wall 10a, and the pressure relief mechanism 30 is disposed on the first wall 10a. The weak portion 31 is configured to be destroyed when the pressure inside the casing reaches a pressure threshold. The body portion 32 is configured to rotate or detach from the first wall 10a when the weak portion 31 is destroyed. Alternatively, the weak portion 31 may be located inside the body portion 32, so that when the weak portion 31 is destroyed, at least a portion of the body portion 32 rotates or detaches from the first wall 10a. Or, the weak portion 31 may be located on the connection area a between the body portion 32 and the first wall 10a, so that when the weak portion 31 is destroyed, the entire body portion 32 rotates or detaches from the first wall 10a.

[0102] Furthermore, the vent 41 is used to connect the inside and outside of the housing 10, so that the gas generated during the charging and discharging of the internal electrode assembly 20 of the battery cell 100 can be discharged through the vent 41. At least part of the vent 41 is provided in the body part 32, that is, the venting mechanism 40 can be at least partially combined with or integrated with the pressure relief mechanism 30.

[0103] Specifically, the connection area a between the body portion 32 and the first wall 10a is formed as a weak portion 31, and / or a weak portion 31 is formed in the body portion 32 and at least a vent hole 41 is provided in the body portion 32. The weak portion 31 is adapted to disconnect the connection between the body portion 32 and the first wall 10a when the pressure in the receiving cavity exceeds the pressure threshold, or to open at least a portion of the body portion 32 in the body portion 32.

[0104] In other words, in some embodiments, the outer casing 10 has a first wall 10a, and a pressure relief mechanism 30 can be further provided in the first wall 10a. The connection area a between the body part 32 of the pressure relief mechanism 30 and the first wall 10a can be formed as a weak part 31 so that when the pressure in the receiving cavity exceeds the pressure threshold, the connection between the body part 32 and the first wall 10a can be disconnected to release the pressure. In other embodiments, the weak part 31 can also be formed in the body part 32 so that when the pressure in the receiving cavity exceeds the pressure threshold, the weak part 31 can be disconnected to open at least a part of the body part 32. Of course, while providing the weak part 31 in the body part 32, the connection area a between the body part 32 and the first wall 10a can also be constructed as a weak part 31. This can also achieve the goal of opening at least part or all of the body part 32 for release after disconnecting the weak part 31.

[0105] Furthermore, at least part of the exhaust port 41 can be formed inside the body portion 32, or it can be formed on the weak portion 31, so that the gas generated during the operation of the electrode assembly 20 inside the housing 10 can be exhausted through the exhaust port 41.

[0106] Furthermore, the weak portion 31 is a key technical feature for the body portion 32 to achieve venting. The weak portion 31 can be used to connect the body portion 32 to the first wall 10a so that the body portion 32 can be fully opened during venting. The weak portion 31 can also be formed inside the body portion 32 so that the body portion 32 can be at least partially opened to achieve venting. Of course, the weak portion 31 can be formed simultaneously in the connection area a between the first wall 10a and the body portion 32 and inside the body portion 32 to improve the venting stability and reliability of the body portion 32.

[0107] It is understood that the fact that at least part of the vent 41 is provided in the body part 32 means that the vent 41 is provided in the body part 32, and that the vent 41 is also formed on the weak part 31 and the first wall 10a.

[0108] It is understandable that in the prior art, the exhaust mechanism 40 is located outside the pressure relief mechanism 30. When the pressure inside the housing 10 (i.e., the accommodating cavity) increases sharply, more airflow will concentrate in the area where the exhaust mechanism 40 is located, resulting in a significant increase in pressure in the area where the exhaust mechanism 40 is located. This also exacerbates the uneven pressure distribution of the first wall 10a as a whole, and the valve opening response speed of the pressure relief mechanism 30 will also be affected. In this application, at least some of the exhaust holes 41 can be located within the projected outline of the body part 32. Therefore, the pressure in the area of ​​the exhaust holes 41 can also act and be dispersed into the body part 32, making the pressure borne by the body part 32 closer to the actual pressure and with a lower error. This allows the body part 32 to respond in a timely manner, improves the valve opening timeliness, and enhances safety.

[0109] According to the battery cell 100 of this application embodiment, the venting mechanism 40 realizes gas generation and venting, while the pressure relief mechanism 30 realizes pressure relief and discharge. At least some of the vent holes 41 can be located inside the body part 32. According to the battery cell 100 of this application embodiment, the venting mechanism 40 realizes gas generation and venting, while the pressure relief mechanism 30 realizes pressure relief and discharge. At least some of the vent holes 41 can be located inside the body part 32. On the one hand, the venting mechanism 40 and the pressure relief mechanism 30 are integrated (i.e., a composite venting and pressure relief mechanism), which has lower requirements for the space size of the first wall 10a and is easier to set up. On the other hand, the venting mechanism 40 and the pressure relief mechanism 30 can be linked to realize venting in normal working mode and venting in abnormal conditions. It can also reduce the impact of uneven pressure distribution and pressure error in the accommodating cavity on the valve opening of the pressure relief mechanism 30, thereby improving safety and reliability.

[0110] It should be noted that the weak part 31 can be formed between the body part 32 and the first wall 10a to connect the first wall 10a and the body part 32. The weak part 31 can also be formed inside the body part 32. Of course, the weak part 31 can be formed both between the body part 32 and the first wall 10a and inside the body part 32.

[0111] Referring to Figures 7, 8 and 8, the housing 10 may include a housing 11 and an end cap 12, the end cap 12 being disposed at at least one end of the housing 11, the first wall 10a being located on the housing 11 and / or the end cap 12.

[0112] In other words, one or more first walls 10a can be provided on the outer casing 10, and a pressure relief mechanism 30 can be provided on each first wall 10a. For example, while the end cap 12 is provided with a pressure relief mechanism 30, a pressure relief mechanism 30 can also be formed on one or more walls of the casing 11. The pressure relief mechanism 30 is further provided with a body part 32 inside, and the exhaust port 41 is at least partially provided in the body part 32.

[0113] Therefore, the battery cell 100 of this application embodiment can be provided with a weak part 31 and a body part 32 at a suitable position on the end cover 12 or the housing 11 based on the pressure relief and venting requirements. That is, a composite venting and venting mechanism 30 is provided at a reasonable position, which reduces the spatial size requirements of the end cover 12 and the housing 11, lowers the restrictions on the setting position, and makes it easier to set up the composite venting and venting mechanism 30.

[0114] The following description, with reference to Figures 10-15, illustrates several structural forms of the pressure relief mechanism 30 according to embodiments of this application. These are merely illustrative examples and not exhaustive.

[0115] It should be noted that the weak part 31 located within the body part 32 is defined as the first weak part 31a, while the weak part 31 located in the connection area a between the body part 32 and the first wall 10a is defined as the second weak part 31b.

[0116] It is understood that the weak part 31 may include: a first weak part 31a, the main body 32 is connected to the first wall 10a, and the first weak part 31a is provided inside the main body 32.

[0117] Specifically, the first weak part 31a is located inside the body part 32. The connection area a between the body part 32 and the first wall 10a and the first weak part 31a can be spaced apart, or the first weak part 31a and the connection area a can be connected. By directly setting the first weak part 31a inside the body part 32, the processing difficulty of the pressure relief mechanism 30 is lower, and the first weak part 31a is less affected during the assembly of the pressure relief mechanism 30 to the first wall 10a, which can improve the stability and reliability of the first weak part 31a.

[0118] Referring to Figures 10-15, according to some embodiments of this application, at least a portion of the exhaust port 41 is located within the body portion 32, and the weak portion 31 is connected to the exhaust port 41, or the weak portion 31 is spaced apart from the exhaust port 41.

[0119] In other words, the exhaust port 41 may include an exhaust port 41 located within the body portion 32. The exhaust port 41 located within the body portion 32 may be connected to the weak portion 31, such as being connected to the first weak portion 31a or the second weak portion 31b. Of course, the weak portion 31 may also be spaced apart from the exhaust port 41, such as being spaced apart from the first weak portion 31a or the second weak portion 31b, or being connected to the first weak portion 31a and spaced apart from the second weak portion 31b, or being connected to the second weak portion 31b and spaced apart from the first weak portion 31a.

[0120] Therefore, in the embodiment where the weak part 31 is connected to the vent hole 41, the vent hole 41 can help limit the weak part 31 and reduce the processing difficulty of the weak part 31. In the embodiment where the weak part 31 and the vent hole 41 are spaced apart, the vent hole 41 has a smaller impact on the weak part 31, and the reliability and stability of the pressure relief mechanism 30 are higher.

[0121] First embodiment:

[0122] As shown in Figure 10, in the first embodiment, the first weak part 31a is annular, the first weak part 31a is arranged around the exhaust hole 41, and / or the exhaust hole 41 is located outside the surrounding area of ​​the first weak part 31a.

[0123] Specifically, in the first embodiment, the first weak part 31a can be annular, and the annular first weak part 31a can be one and located within the body part 32, or multiple and located within the body part 32. The first weak part 31a can be arranged around the exhaust hole 41, and the exhaust hole 41 can also be located outside the range defined by the first weak part 31a.

[0124] Thus, in the embodiment where the first weak portion 31a surrounds the vent hole 41, when the first weak portion 31a causes at least a portion of the body portion 32 to detach from or flip relative to the first wall 10a, a discharge area larger than the vent hole 41 can be opened to achieve rapid discharge. In the embodiment where the vent hole 41 is located outside the area enclosed by the first weak portion 31a, the vent hole 41 can also participate in the discharge process simultaneously during discharge, which can further increase the discharge area and improve the discharge efficiency.

[0125] As shown in FIG10, according to some embodiments of the present application, a first weak portion 31a is provided around one or more vent holes 41.

[0126] Specifically, the first weak part 31a can be arranged around an exhaust hole 41, and the exhaust holes 41 can be arranged in rows or columns within the body part 32. Correspondingly, the first weak part 31a can be arranged around multiple exhaust holes 41 arranged in rows or columns.

[0127] Therefore, on the one hand, directional pressure relief can be achieved. The annular first weak part 31a surrounds the exhaust port 41, and the exhaust port 41, as an exhaust structure, can play the role of gathering airflow before the valve is opened, so that the internal pressure can be directly guided to be discharged quickly through the exhaust port 41, and the thermal runaway propagation speed can be reduced. On the other hand, the annular first weak part 31a can distribute stress evenly and avoid local stress concentration, so as to control the first weak part 31a to break synchronously, which can effectively improve the relief efficiency.

[0128] Second embodiment:

[0129] In the second embodiment, the two ends of the first weak part 31a are respectively connected to two exhaust holes 41.

[0130] Specifically, as shown in Figure 11, the body portion 32 is connected to the first wall 10a, while the first weak portion 31a is used to connect any two exhaust holes 41 located within the body portion 32.

[0131] The second weak part 31b is connected between any two vent holes 41 in the main body 32. By providing the second weak part 31b between the two vent holes 41, the second weak part 31b between the two vent holes 41 can break quickly during the venting process, so that the area between the two vent holes 41 is further formed into a venting area, so as to quickly achieve venting.

[0132] Referring to Figure 11, according to some embodiments of this application, the two ends of the first weak portion 31a are connected to two adjacent exhaust holes 41.

[0133] In other words, the second weak part 31b can be set between two adjacent vent holes 41 so that the area between the adjacent vent holes 41 can be separated or flipped, thereby opening a discharge area larger than the vent hole 41, which can improve the discharge efficiency. Furthermore, the first weak part 31a is set between the adjacent vent holes 41. The first weak part 31a is easier to set, and the first weak part 31a has higher reliability and stability in response to the internal pressure of the battery cell 100.

[0134] Third embodiment:

[0135] In the third embodiment, one end of the first weak part 31a is connected to the vent 41, and the other end of the first weak part 31a extends toward the connection area a between the body part 32 and the first wall 10a.

[0136] It should be noted that one end of the first weak part 31a is connected to the vent 41 located in the body part 32, and the other end of the first weak part 31a can extend toward the connection area a between the first wall 10a and the body part 32. This means that one end of the first weak part 31a can be connected to the vent 41 and the other end can be connected to the connection area a. Alternatively, one end of the first weak part 31a can be connected to the vent 41 located in the body part 32, and the other end of the first weak part 31a can be connected to the vent 41 located on the periphery of the body part 32. Alternatively, one end of the first weak part 31a can be connected to the vent 41 located in the body part 32, and the other end of the first weak part 31a can be connected to another first weak part 31a with a ring structure.

[0137] Specifically, as shown in Figure 12, the first weak part 31a can extend to the edge of the main body 32 at one end and be connected to the exhaust port 41 at the other end. This allows multiple first weak parts 31a to open, creating a pressure relief area larger than the exhaust port 41 and smaller than or equal to the main body 32, thus achieving rapid pressure relief. Of course, one end of the first weak part 31a is directly connected to the exhaust port 41, and the other end is connected to the first weak part 31a of the annular shape. This allows the annular first weak part 31a to cooperate with the first weak part 31a connected to the exhaust port 41, ensuring that the main body 32 can open the valve stably and reliably. It can also achieve initial guidance for pressure relief and avoid excessive airflow range during the initial pressure relief process. It can also reduce the speed of thermal runaway propagation. Furthermore, the airflow relief range is small and highly directional in the initial stage, which can cooperate with the discharge path to achieve rapid pressure relief. As the pressure further increases, the annular first weak part 31a opens further to increase the area of ​​the pressure relief region, thereby improving the reliability and safety of the pressure relief process.

[0138] It is understandable that the annular first weak part 31a and the first weak part 31a used to connect any two exhaust holes 41 located in the body part 32, one end of which is connected to the exhaust hole 41 and the other end of which extends toward the connection area a, can be provided in the body part 32 at the same time.

[0139] Hereinafter, with reference to Figures 10-13, the first weak part 31a of the present application embodiment will be described by way of example. The annular first weak part 31a is defined as the first sub-weak part, the first weak part 31a used to connect any two exhaust holes 41 located in the body part 32 is defined as the second sub-weak part, and the first weak part 31a with one end connected to the exhaust hole 41 and the other end extending toward the connection area a is defined as the third sub-weak part.

[0140] The first weak portion 31a is formed inside the body portion 32, the exhaust hole 41 is located inside the body portion 32, and the first weak portion 31a is arranged around the exhaust hole 41, or at least one end of the first weak portion 31a is connected to the exhaust hole 41, or at least one end of the first weak portion 31a is connected to the edge of the body portion 32.

[0141] Specifically, the body portion 32 is used to open fully or at least partially for pressure relief, and the boundary of the body portion 32 is the area where the body portion 32 is connected to the first wall 10a. However, the connection area a is not limited to being formed as the first weak portion 31a. That is, the first weak portion 31a can be located inside the body portion 32 for opening at least part of the body portion 32 to achieve pressure relief.

[0142] In some embodiments, as shown in Figures 10 and 13, the first weak part 31a surrounding the exhaust hole 41 means that a part that can break under pressure is provided around the exhaust hole 41. When the pressure inside the accommodating cavity reaches the pressure threshold, the first weak part 31a will break first, thereby quickly releasing the pressure and making the opening area of ​​the body part 32 larger than the exhaust hole 41 to achieve rapid venting.

[0143] Referring to Figures 11, 12, and 13, at least one end of the first weak portion 31a is connected to the vent 41, or at least one end of the first weak portion 31a is connected to the edge of the body portion 32. This means that in some embodiments, both ends of the first weak portion 31a can be connected to the vent 41 and the edge of the body portion 32, respectively; or one end of the first weak portion 31a can be connected to the first weak portion 31a surrounding the vent 41, and the other end can be connected to the vent 41; or both ends of the first weak portion 31a can be connected to two vents 41. This is so that when the pressure inside the accommodating cavity reaches the pressure threshold, the periphery of the vent 41 breaks, making the opening area of ​​the body portion 32 larger than the area of ​​the vent 41, making the pressure relief process more direct and effective.

[0144] Of course, by providing a first weak portion 31a surrounding the vent hole 41 and / or a first weak portion 31a connected to the vent hole 41, on the one hand, the opening area of ​​the main body 32 during venting can be increased to vent pressure larger than the vent hole 41, thereby improving venting efficiency. On the other hand, it can be ensured that when the pressure inside the accommodating cavity exceeds the pressure threshold, the fracture of the first weak portion 31a can effectively expand the main body 32, accelerate pressure release, and at the same time, the direction and range of the rupture can be controlled to improve safety.

[0145] Understandably, the first weak point 31a can be constructed as a groove formed within the body portion 32.

[0146] Specifically, the first weak part 31a can be achieved by setting grooves in the body part 32. As a weakening treatment, the grooves can reduce the structural strength of the first weak part 31a by creating shallow grooves, indentations or fine cutting lines on the surface or inside of the material, making it easier for it to break under pressure compared to the surrounding first wall 10a and other areas of the body part 32. Furthermore, by setting the grooves, the body part 32 can undergo controlled fracture according to the shape of the grooves, and the direction of pressure relief can be controlled to avoid more serious thermal runaway problems.

[0147] Of course, score-guided fracture can also control energy release and reduce the power of thermal runaway.

[0148] As shown in Figures 10 and 13, according to some embodiments of this application, the first weak portion is annular and surrounds the exhaust port 41.

[0149] For example, the annular notch can be a circular ring, an oblong ring, a rectangular ring, a triangular ring, etc.

[0150] Specifically, the first weak part is annular and surrounds the vent hole 41, which can release pressure in a targeted manner around the vent hole 41. On the one hand, it can achieve directional pressure relief: the annular first weak part surrounds the vent hole 41, and the vent hole 41, as the venting mechanism 40, can collect airflow before the valve is opened, thereby directly guiding the internal pressure to be quickly discharged through the vent hole 41 and the area around the vent hole 41, and reducing the rate of thermal runaway propagation. On the other hand, the annular first weak part 31a can distribute stress evenly and avoid local stress concentration, thereby controlling the synchronous fracture of the internal area of ​​the annular first weak part 31a, which can effectively improve the release efficiency.

[0151] As shown in Figures 11 and 13, according to some embodiments of this application, the second weak portion is connected between adjacent exhaust holes 41.

[0152] The second weak section is connected between adjacent vent holes 41. By setting the second weak section between adjacent vent holes 41, the second weak section between adjacent vent holes 41 can be quickly broken during the venting process, so that the area between adjacent vent holes 41 can be further formed into a venting area to quickly achieve venting.

[0153] As shown in Figures 12 and 13, according to some embodiments of this application, one end of the third sub-weak portion is connected to the vent 41, and the other end extends to the edge of the body portion 32, or is connected to the first sub-weak portion.

[0154] It should be noted that the third sub-weak part and the first sub-weak part can be set at the same time, or only the first sub-weak part or only the third sub-weak part can be set. This application does not impose specific restrictions.

[0155] In this way, the third weak part can extend to the edge of the main body 32 at one end and be connected to the exhaust port 41 at the other end. This allows multiple third weak parts to open, thus opening a pressure relief section larger than the exhaust port 41 and smaller than or equal to the main body 32, achieving rapid pressure relief. Of course, one end of the third weak part is directly connected to the exhaust port 41, and the other end is connected to the first weak part, allowing the first weak part to cooperate with the third weak part to ensure that the main body 32 can open the valve stably and reliably. The third weak part opens first, and the first weak part opens as the pressure further increases, which can achieve initial guidance of pressure relief and avoid excessive airflow range during the initial pressure relief process. It can also reduce the speed of thermal runaway propagation. Moreover, the airflow relief range is small and highly directional in the initial stage, which can cooperate with the discharge path to achieve rapid pressure relief. As the pressure further increases, the first weak part breaks to increase the opening area of ​​the main body 32, thereby improving the reliability and safety of the pressure relief process.

[0156] According to some embodiments of this application, the other end of the third weak portion extends to the corner of the body portion 32, or to the corner of the first weak portion.

[0157] It should be noted that the main body 32 can be a rectangle, triangle or other polygon, and the other end of the third sub-weak part can extend to the corner of the main body 32, or the first sub-weak part can be a triangular ring, a rectangular ring or the like, and the other end of the third sub-weak part can extend to the corner of the first sub-weak part.

[0158] Thus, in the embodiment where the third weak part extends directly to the edge of the main body 32, after the third weak part is opened, an opening extending to the edge of the main body 32 can be formed to increase the pressure relief area and improve the pressure relief effect. In the embodiment where the third weak part extends to the edge of the first weak part, the third weak part and the first weak part can be opened simultaneously or sequentially, which can improve the valve opening response speed of the main body 32, open the valve in time, and improve safety and reliability.

[0159] It is understandable that the second sub-weak section can be set up simultaneously with the third and first sub-weak sections so that during the venting process, the second, third, and first sub-weak sections can be opened sequentially to limit the venting path. This allows for highly directional gas flow during venting and gradually increases the venting area as the pressure increases. This not only improves the stability and reliability of the venting but also slows down the spread of thermal runaway. The second, third, and first sub-weak sections can also be opened simultaneously to achieve rapid venting.

[0160] It is understandable that the first, second, and third sub-weak parts are all suitable for being constructed as grooves, while the extension trajectories of the second and third sub-weak parts are all formed as straight line segments.

[0161] Therefore, straight-line notches are easier to process and control than curves or other complex shapes, which can reduce costs and improve production efficiency. In addition, they can improve the predictability of fracture behavior. Furthermore, the weakened area formed by straight notches in the material is conducive to the more uniform transmission of stress during the fracture process, avoiding local stress concentration, so that the second sub-weak part and the second sub-weak part can fracture in time to achieve stress release.

[0162] For example, in an embodiment where the first sub-weak portion, the second sub-weak portion, and the third sub-weak portion are all constructed as grooves and are respectively defined as the first groove, the second groove, and the third groove, the groove depth of the first groove is D1, the groove depth of the second groove is D2, and the groove depth of the third groove is D3, and satisfies: D3 < D2 < D1, or D1 = D2 = D3.

[0163] In other words, in some embodiments, D3 < D2 < D1, so that the third, second, and first notches are opened sequentially; in other embodiments, D1 = D2 = D3, so that the first, second, and third notches are opened simultaneously.

[0164] It is understandable that in embodiments where the first, second, and third notches are opened sequentially, the order of opening can also be set to guide the cracked portion of the main body 32 during the opening process, thereby reducing the impact of opening the cracked portion and reducing the influence range of the main body 32 during the opening process, and reducing the probability of damaging surrounding components during the opening process of the main body 32.

[0165] It should be noted that, in the embodiments of this application, the first, second, and third grooves can be processed onto the housing 11 or end cap 12 by laser etching. The depths of the first, second, and third grooves are different, which can be achieved by adjusting the output power of the laser etching equipment. The measurement of groove depth can be achieved by using a microscope in conjunction with a high-precision optical probe.

[0166] It is understandable that, as shown in Figure 15, while the weak part 31 is used to connect the first wall 10a, the first, second and third grooves can also be set in the body part 32 at the same time, so that the discharge response speed and discharge effect of the body part 32 are better.

[0167] As shown in FIG14, according to some embodiments of this application, the weak portion 31 further includes a second weak portion 31b, wherein the connection region a between the body portion 32 and the first wall 10a is formed as the second weak portion 31b.

[0168] In other words, the area where the first wall 10a is connected to the body part 32 is formed as a weak part 31. In order to distinguish it from the weak part 31 formed in the body part 32, it is defined as a second weak part 31b. The first weak part 31a and the second weak part 31b can be set simultaneously, or only one of the first weak part 31a and the second weak part 31b can be set.

[0169] In this way, by setting the second weak part 31b, when the internal pressure of the outer shell 10 exceeds the pressure threshold, the main body 32 can be completely separated from the first wall 10a or flipped relative to the first wall 10a to achieve rapid release.

[0170] As shown in Figures 14 and 15, according to some embodiments of this application, an exhaust port 41 is disposed within the body portion 32, and / or the exhaust port 41 is formed in the connection region a between the body portion 32 and the first wall 10a.

[0171] The second weak portion 31b can be used to weaken the connection between the main body portion 32 and the first wall 10a, and the vent 41 is provided in the main body portion 32. Alternatively, the second weak portion 31b can be used to weaken the connection between the main body portion 32 and the first wall 10a, and the vent 41 is formed in the connection area a and can participate in defining the second weak portion 31b. Alternatively, the vent 41 includes a first part of the vent 41 formed in the main body portion 32 and a second part of the vent 41 that participates in defining the second weak portion 31b.

[0172] In this embodiment, where the second weak portion 31b weakens the connection and the vent 41 is formed within the body portion 32, the vent 41 has less impact on the second weak portion 31b and higher stability. In the embodiment where the second weak portion 31b weakens the connection and the vent 41 participates in defining the second weak portion 31b, the setting of the second weak portion 31b is easier. In the embodiment where the vent 41 includes a first part and a second part, the number of vent 41 is greater and the venting efficiency is higher, which can timely discharge the gas generated during the charging and discharging of the battery cell 100 and improve the venting efficiency.

[0173] As shown in FIG15, according to some embodiments of the present application, the exhaust hole 41 located in the body portion 32 is spaced apart from the second weak portion 31b, and the exhaust hole 41 located in the connection region a between the body portion 32 and the first wall 10a is connected to the second weak portion 31b.

[0174] In this way, on the one hand, the exhaust hole 41 located in the connection area a is connected to the second weak part 31b, which can at least partially disconnect the connection area a between the first wall 10a and the body part 32. While participating in the limitation of the second weak part 31b, the number of exhaust holes 41 can be increased and the exhaust efficiency can be improved. On the other hand, the exhaust holes 41 located in the body part 32 are spaced apart from the second weak part 31b, which can reduce the structural impact of the exhaust holes 41 located in the body part 32 on the second weak part 31b.

[0175] According to some embodiments of this application, the weak part 31 is constructed as any one of a weld, a local break, or a notch.

[0176] For example, the first weak part 31a located in the body part 32 can be constructed as a groove or a weld, while the second weak part 31b is located on the connection area a between the body part 32 and the first wall 10a, and it can be formed as either a weld or a groove. Of course, in the embodiment where an exhaust hole 41 is provided in the connection area a, the second weak part 31b can also be constructed as a local break.

[0177] Therefore, based on the location of the weak part 31, a reasonable structure of the weak part 31 can be selected, which can reduce the difficulty of setting the weak part 31 and the processing difficulty of the main body 32.

[0178] Referring to Figures 7, 8 and 9, according to some embodiments of this application, the weak part 31 is constructed as a weld, and the weld penetration depth is 0.3 mm to 0.5 mm.

[0179] In other words, the weld penetration depth can be 0.3mm, 0.4mm, 0.5mm, etc., so that the weld strength is less than the structural strength of the first wall 10a and the main body 32. When under pressure, the area where the weld is located can be opened first to achieve rapid pressure relief. Of course, the weld can also be set synchronously with the weak parts 31 of other structures to open sequentially or simultaneously to improve the pressure relief effect.

[0180] Understandably, a weld penetration depth of not less than 0.3 mm can ensure that the connection strength between the weld and the first wall 10a meets the needs of daily use, reduce the probability of accidental valve opening, and improve stability and reliability. A weld penetration depth of not more than 0.5 mm can make the valve opening response of the body part 32 more timely and improve safety.

[0181] It should be noted that the vent 41 can be constructed as a circular hole, an elliptical hole, a square hole, etc., and this application does not specifically limit it.

[0182] Furthermore, the number of exhaust holes 41 is 3 to 10, such as 3, 4, 5, 6, 7, 8, 9, 10, etc., preferably 4 to 5 (i.e. 4 or 5).

[0183] This makes the number of exhaust holes 41 more reasonable. On the one hand, the opening area of ​​a single exhaust hole 41 is more reasonable, which can reduce the pollution caused by large particles falling. On the other hand, it reduces the number of holes in the main body 32, and the area of ​​each hole area is more reasonable, which can also reduce the impact on the structural strength of the main body 32, thereby reducing the probability of accidental valve opening and improving operational stability and reliability.

[0184] According to some embodiments of this application, there are multiple exhaust holes 41, and the total exhaust area of ​​the multiple exhaust holes 41 is S1. When the weak part 31 is damaged, it rotates or detaches relative to the first wall 10a to define an exhaust area located on the first wall 10a. The area of ​​the exhaust area is S2, and satisfies: 0 < S1 / S2 < 0.6.

[0185] For example, the total area of ​​the vent 41 can be 0.1 times, 0.2 times, 0.3 times, 0.4 times, 0.5 times, etc., of the area of ​​the body part 32.

[0186] Therefore, the total area of ​​the exhaust port 41 is smaller than the area of ​​the main body 32, and the maximum area of ​​the exhaust port 41 is less than 0.6 times the total area of ​​the main body 32, so as to balance the exhaust effect and the pressure relief protection effect. That is, if the area is too large, it will lead to over-exhaust. After the pressure is transmitted to the main body 32, the main body 32 cannot respond in time and it is difficult to open the valve in time, which reduces safety.

[0187] As shown in Figure 4, according to some embodiments of this application, the outer shell 10 is constructed as a cylinder. The outer shell 10 includes an end cap 12 and a housing 11. The end cap 12 defines a first wall 10a, and the area of ​​the first wall 10a is S3, which satisfies: 0 < S2 / S3 < 0.3.

[0188] Specifically, the area of ​​the first wall 10a (the area of ​​the end cap 12) and the area of ​​the body 32 satisfy 0 < S2 / S3 < 0.3, that is, the area of ​​the body 32 can be 0.1 times, 0.2 times, etc. of the area of ​​the end cap 12.

[0189] This makes the area of ​​the main body 32 smaller than 0.3 times the area of ​​the end cover 12, making the space occupied by the main body 32 on the end cover 12 more reasonable.

[0190] It is understandable that in a cylindrical battery structure, the end cap 12 needs to be equipped with electrode terminals 122, liquid injection holes, and other structures. However, the end cap 12 itself is relatively small, and the body part 32 needs to be set in other areas of the electrode terminals 122 and liquid injection holes, resulting in a small allowable area for the body part 32. This makes the area of ​​the body part 32 less than 0.3 times the area of ​​the end cap 12, making the space occupied by the body part 32 on the end cap 12 more reasonable and reducing the difficulty of setting the body part 32.

[0191] As shown in Figure 3, according to some embodiments of this application, the outer shell 10 is constructed as a prism, the first wall 10a is defined by any surface of the prism, the area of ​​the first wall 10a is S4, and satisfies: 0 < S2 / S4 < 0.1.

[0192] This makes the space occupied by the main body 32 on the end cap 12 or the housing 11 more reasonable. It can not only avoid the valve opening area being too large and improve the protection effect, but also make the opening response speed of the main body 32, which has a more reasonable area size, more reasonable when subjected to the internal pressure of the housing 10. It can achieve rapid response and rapid valve opening, thereby improving safety and reliability.

[0193] According to some embodiments of this application, the exhaust mechanism 40 includes a waterproof and breathable membrane 42, which is disposed on the side of the first wall 10a facing the electrode assembly 20, and the orthographic projection outline of each exhaust hole 41 facing the electrode assembly 20 falls within the orthographic projection outline of the waterproof and breathable membrane 42 facing the electrode assembly 20.

[0194] Specifically, the vent 41 is covered with a waterproof and breathable membrane 42 (usually a thin membrane that only allows gas to pass through in one direction) to ensure that the gas generated inside the casing 10 can only be discharged from the inside of the casing 10 to the outside, while outside air or impurities cannot enter in the reverse direction, thus protecting the purity and safety of the battery's internal environment.

[0195] In other words, a waterproof and breathable membrane 42 is disposed on the side of the main body 32 facing the receiving cavity (i.e., the internal space where the electrode assembly 20 is located). The exhaust port 41 cooperates with the waterproof and breathable membrane 42 to realize the generation and exhaust of gas inside the battery cell 100. The outer periphery of the exhaust port 41 is the main body 32 or the connecting area a. When the internal pressure of the area where the main body 32 is located exceeds the pressure threshold, the main body 32 is at least partially opened to achieve the release.

[0196] Therefore, the waterproof and breathable membrane 42 is located on the side of the main body 32 facing the electrode assembly 20. The waterproof and breathable membrane 42 covers the exhaust hole 41 and can be used to allow the gas generated inside the housing 10 to be discharged in one direction. It also has a certain waterproof effect, which can prevent foreign objects from entering the housing 10 and improve the safety and reliability of the battery cell 100.

[0197] According to some embodiments of this application, the orthographic projection profile of the waterproof and breathable membrane 42 toward the electrode assembly 20 is spaced apart from the orthographic projection profile of the weak portion 31 toward the electrode assembly 20.

[0198] In other words, the waterproof and breathable membrane 42 is offset from the weak part 31, so that the internal pressure of the outer shell 10 can be directly applied to the weak part 31, reducing the impact of the waterproof and breathable membrane 42 on the weak part 31, thereby improving the reliability and stability of the battery cell 100.

[0199] According to some embodiments of this application, the pressure relief mechanism 30 is integrally formed with the first wall 10a, or the pressure relief mechanism 30 is assembled on the first wall 10a.

[0200] In some embodiments, the body portion 32 can be constructed as a separate plate structure with an exhaust hole 41. The plate structure can be connected to the first wall 10a through a second weak portion 31b. One or more first weak portions 31a can be further provided inside the body portion 32 so that the plate structure can be fully or at least partially opened to achieve pressure relief. In other embodiments, the body portion 32 is integrally formed with the first wall 10a, and a region is divided on the first wall 10a to form the body portion 32. The body portion 32 can be further provided inside the body portion 32 to achieve pressure relief by at least partially opening the body portion 32.

[0201] As shown in Figure 10, in the first embodiment of this application, the first weak part 31a is constructed as a ring, and the first weak part 31a is arranged around a plurality of exhaust holes 41.

[0202] As shown in FIG11, in the second embodiment of this application, the first weak part 31a is used to connect the adjacent exhaust port 41.

[0203] As shown in FIG12, in the third embodiment of this application, one end of the first weak portion 31a is connected to the exhaust hole 41 located in the body portion 32, and the other end of the first weak portion 31a extends to the edge of the body portion 32.

[0204] As shown in FIG13, in the fourth embodiment of this application, the first weak portion 31a includes a first sub-weak portion disposed around the exhaust hole 41, a second sub-weak portion connecting adjacent exhaust holes 41, and a third sub-weak portion having one end connected to the exhaust hole 41 and the other end extending to the edge of the body portion 32.

[0205] It should be noted that one end of the third weak part is connected to the main body 32, and the other end can also extend to the first weak part and be connected to the first weak part.

[0206] As shown in FIG14, in the fifth embodiment of this application, the connection area a between the main body 32 and the first wall 10a is formed as a second weak part 31b, and an exhaust hole 41 is formed on the second weak part 31b.

[0207] As shown in FIG15, in the sixth embodiment of this application, the first weak portion 31a includes a first sub-weak portion surrounding the exhaust hole 41, a second sub-weak portion connecting adjacent exhaust holes 41, and a third sub-weak portion having one end connected to the exhaust hole 41 and the other end extending to the edge of the body portion 32. The connection area a between the body portion 32 and the first wall 10a is formed as the second weak portion 31b, and the exhaust hole 41 is formed on the second weak portion 31b.

[0208] It should be noted that one end of the third weak part is connected to the main body 32, and the other end may extend to connect with the second weak part 31b, or connect with the vent 41 formed on the second weak part 31b.

[0209] According to some embodiments of this application, the battery cell 100 is configured as an alkali metal battery.

[0210] Therefore, this application further provides a pressure relief mechanism 30 and an exhaust mechanism 40 on the first wall 10a of the casing 10, which can discharge the gas generated inside the battery cell 100 in a timely manner through the exhaust mechanism 40, so as to maintain the internal pressure stability of the battery cell 100 and improve the safety and reliability of the alkali metal battery.

[0211] It should be further noted that existing alkali metal batteries generally use a vented top cover to expel the hydrogen gas generated inside the alkali metal battery, thereby protecting the alkali metal battery. Since different types of alkali metal batteries (such as lithium metal batteries and sodium metal batteries) have different chemical systems (electrolyte / positive electrode / negative electrode, etc.) and structural designs, the gas production rate and gas production amount also vary greatly. Therefore, a vented top cover design with different gas permeability is required, which increases the process flow and investment cost of vented top cover manufacturing.

[0212] Based on this, the present application can further provide a gas storage structure in the gap between the electrode assembly 20 and the housing 11. The gas storage structure can absorb gas, and when the gas storage structure is difficult to completely absorb the gas, at least part of the gas can be discharged through the exhaust mechanism of the present application. Through the organic combination of the exhaust mechanism and the gas storage structure, the reliability and safety of the battery cell 100 can be further improved.

[0213] At least part of the gas storage structure is hydrogen storage metal. The hydrogen storage metal can absorb a large amount of hydrogen produced by the alkali metal battery, so that the hydrogen can be absorbed at a low pressure level, that is, when there is very little hydrogen. The amount of hydrogen that can be absorbed and the absorption rate are much higher than those of the ventilated top cover. This can reduce the internal pressure of the alkali metal battery, reduce the risk of thermal runaway of the alkali metal battery, and extend the life of the alkali metal battery.

[0214] Furthermore, this application incorporates a hydrogen storage metal within the alkali metal battery, which can directly absorb the hydrogen gas produced by the alkali metal battery. This is applicable to various types of alkali metal batteries, reducing the probability of hydrogen gas escaping into the battery module or battery pack, further lowering the risk of thermal runaway. It also reduces the alkali metal battery's sensitivity to moisture, improves its mechanical strength, and ultimately extends its lifespan. In summary, the alkali metal battery embodiments of this application can reduce the internal pressure of the alkali metal battery, decrease the risk of thermal runaway, and extend its cycle life.

[0215] It is understandable that alkali metal batteries refer to batteries that achieve cycling by depositing and consuming alkali metals at the negative electrode. When preparing the negative electrode sheet, an alkali metal layer may be formed or may not be formed (a battery without a negative electrode). In addition, the active metals of alkali metal batteries are not limited to lithium, sodium, and potassium, but may also include other active metals such as zinc and aluminum.

[0216] It is understandable that hydrogen storage metal refers to an alloy that can react with hydrogen and thus absorb hydrogen. The reaction process between hydrogen storage metal and hydrogen is as follows: First, hydrogen is catalyzed and decomposed into hydrogen atoms on the surface of the hydrogen storage metal. Then, the hydrogen atoms enter the interior of the hydrogen storage metal lattice to generate metal hydrides, thus achieving the purpose of hydrogen storage.

[0217] Understandably, the material composition of the aforementioned hydrogen storage metal can be determined using an X-ray diffractometer.

[0218] In some embodiments of this application, under standard conditions, each gram of hydrogen storage metal can absorb 50 mL to 250 mL of hydrogen gas. For example, under standard conditions, the volume of hydrogen gas absorbed by each gram of hydrogen storage metal can be 50 mL to 240 mL, 100 mL to 200 mL, 150 mL to 179 mL, 155 mL to 175 mL, 160 mL to 170 mL, 165 mL to 170 mL, etc. This allows the hydrogen storage metal to absorb a relatively large amount of hydrogen, thus enabling sufficient absorption of hydrogen gas generated by the alkali metal battery even with a low amount of hydrogen storage metal added, reducing the internal pressure of the alkali metal battery, and extending its lifespan. In other embodiments, under standard conditions, each gram of hydrogen storage metal can absorb 50 mL to 180 mL of hydrogen gas.

[0219] As you can understand, standard temperature and pressure (STP), or simply "standard conditions" or "STP", refers to the conditions at 0°C and 101.325 kPa.

[0220] It is understood that "the volume of hydrogen that can be absorbed per gram of hydrogen storage metal under standard conditions" is a well-known definition in the art and can be determined using methods known in the art, such as the following methods:

[0221] Add 1g of hydrogen storage metal to the stainless steel sample chamber. Purge the alloy with hydrogen at a constant pressure of 5MPa for 2 hours. Then evacuate the sample for 30 minutes. Repeat the hydrogen purging-evacuation process at least three times to fully activate the hydrogen storage metal.

[0222] The amount of hydrogen absorbed by the alloy was determined using the H2PCT-1153 three-channel fully automated hydrogen storage material performance testing system (Yangzhou Yinghui Zhiyue).

[0223] According to some embodiments of this application, the electrode assembly 20 includes a negative electrode sheet, the negative electrode sheet includes a negative current collector and an active material layer disposed on at least one side of the negative current collector, the active material layer including an elemental active metal.

[0224] It can be understood that an active metal refers to a metal that can provide active metal ions. For example, the active metal in a lithium-alkali metal battery is elemental lithium, and the active metal in a sodium-alkali metal battery is elemental sodium. In this case, an alkali metal battery is included. Specifically, an alkali metal battery refers to a battery that uses an active metal as the negative electrode, such as lithium metal or sodium metal. In the above-mentioned types of alkali metal batteries, the active metal ions on the negative electrode, such as lithium and sodium, are relatively active and will undergo side reactions with water, solvents in the electrolyte, and residual alkali in the positive electrode active material, resulting in a large amount of gas production, and the proportion of H2 in the gas is >90%. For the above-mentioned batteries where the main gas produced is hydrogen, by setting a hydrogen storage metal in the battery, the hydrogen produced in the battery cell 100 is absorbed, reducing the internal pressure of the alkali metal battery, and the cycle life of the above-mentioned alkali metal battery is significantly improved.

[0225] According to some embodiments of this application, the active metal element includes at least one of lithium, sodium, potassium, zinc, or aluminum.

[0226] The active metal ions in the aforementioned alkali metal batteries are relatively reactive and will undergo side reactions with the electrolyte, producing a large amount of gas, with H2 accounting for >90% of the gas. For the aforementioned batteries that mainly produce hydrogen gas, by setting a hydrogen storage metal in the battery, the hydrogen gas produced in the battery can be absorbed, which is more effective in reducing the internal pressure of the alkali metal battery, and the cycle life of the aforementioned alkali metal batteries is significantly improved.

[0227] In some embodiments of this application, when a lithium metal negative electrode sheet is used, the preparation method is as follows: lithium foil or lithium metal alloy is coated onto the current collector by single-sided rolling, and then cut into negative electrode sheets.

[0228] For example, the alkali metal battery in this application embodiment is a sodium metal battery. When a sodium metal negative electrode sheet is used, its preparation method is as follows: sodium foil or sodium metal alloy is coated onto the current collector by single-sided rolling, and then cut into negative electrode sheets.

[0229] Of course, in other embodiments, the alkali metal battery of this application embodiment can also be constructed as a negative electrode-free battery, that is, there is no alkali metal in the negative electrode sheet. The prepared battery is called a negative electrode-free battery. By setting the interface modification layer, the active metal (alkali metal) can be uniformly deposited on the surface of the interface modification layer, thereby improving the cycle performance of the battery.

[0230] It's understandable that a "negative electrode-free battery" refers to a battery where no negative electrode active material is added during the battery manufacturing stage. However, a negative electrode current collector is still present. A negative electrode-free battery is simply a special type of alkali metal battery (such as lithium metal batteries or sodium metal batteries), not one that truly lacks a negative electrode. In actual operation, the negative electrode still contains an active metal (such as lithium metal or sodium metal). The negative electrode in a negative electrode-free battery includes a bare negative electrode current collector (such as copper). Taking a lithium battery as an example, during charging, active metal ions such as Li+ are released from the positive electrode and deposited on the negative electrode current collector, forming a lithium negative electrode. During subsequent battery discharge, the deposited lithium metal dissolves and is re-intercalated into the positive electrode.

[0231] According to some embodiments of this application, the housing 10 contains an electrolyte, the electrode assembly 20 is immersed in the electrolyte, the electrolyte includes a solvent, and the solvent is configured to be at least one of an ether solvent or an ester solvent.

[0232] First, it should be noted that this application does not impose specific restrictions on the type of electrolyte; it can be selected according to requirements. For example, the electrolyte can be liquid, gel, or completely solid.

[0233] It is understood that ether solvents refer to organic solvents containing ether groups, and ester solvents refer to organic solvents containing ester groups. Ether solvents and ester solvents have good compatibility with the hydrogen storage metal of the embodiments of this application, and hydrogen gas is generated during the cycling process of the alkali metal battery, which is absorbed by the hydrogen storage metal, reducing the internal pressure of the alkali metal battery and extending the life of the alkali metal battery.

[0234] According to some embodiments of this application, the ether solvent includes at least one of 1,2-dimethoxypropane, dimethoxymethane, ethylene glycol dimethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, pentaethylene glycol dimethyl ether, polyethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol diethyl ether, triethylene glycol diethyl ether, tetraethylene glycol diethyl ether, pentaethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dibutyl ether, or 1,3-dioxane.

[0235] The aforementioned ether solvents are compatible with various alkali metal batteries, especially alkali metal batteries, and have good compatibility with the hydrogen storage metal of the present application embodiments. During the cycling process of the alkali metal battery, hydrogen gas is generated, which is absorbed by the hydrogen storage metal, reducing the internal pressure of the alkali metal battery and extending the life of the alkali metal battery.

[0236] In some embodiments of this application, the ester solvent may include at least one selected from ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, or diethyl sulfone.

[0237] In some embodiments of this application, at least a portion of the gas storage structure is a hydrogen storage metal, including zirconium alloys, magnesium alloys, titanium alloys, vanadium alloys, or La. x Ni y M z At least one of the following, wherein M includes at least one of Zr, Mn, Mg, Zn, Al, Ti, Fe, Cu, Co, Y, Ca or Bi, 0 < x ≤ 2, 0 ≤ y ≤ 7, 0 ≤ z ≤ 3.

[0238] As an example, x can be 0.1-1.9, 0.3-1.7, 0.5-1.5, 0.8-1.3, 1-1.2, etc., and in some other embodiments of this application, 0.3≤x≤1.

[0239] y can be 1-6.9, 2-6, 3-5, etc. In some other embodiments of this application, 1≤y≤5.

[0240] z can be 0.1-2.9, 0.5-2.5, 1-2, etc., and in some other embodiments of this application, 0≤z≤1.

[0241] Among the aforementioned elements, Ti and Co can improve the lifespan and kinetics of hydrogen storage metals, Mg can enhance the hydrogen absorption capacity of hydrogen storage metals, Mn and Al can construct the framework of hydrogen storage metals and reduce costs, Y can reduce the hydrogen absorption plateau pressure of hydrogen storage metals, Fe, Ca and Bi can increase the hydrogen desorption plateau pressure of hydrogen storage metals, and Fe can increase the hydrogen absorption plateau pressure of hydrogen storage metals, while Cu can increase the hydrogen absorption rate of hydrogen storage metals.

[0242] In other embodiments of this application, M includes at least one of Al, Mn, Mg, Fe, Y, or Bi.

[0243] The aforementioned hydrogen storage metals have the characteristics of rapid hydrogen absorption, large hydrogen absorption capacity, wide hydrogen absorption boundary, and small volume expansion. They have excellent hydrogen absorption capacity, can absorb hydrogen gas generated by the battery, reduce the internal pressure of the alkali metal battery, reduce the risk of thermal runaway of the alkali metal battery, and extend the life of the alkali metal battery.

[0244] It is understandable that zirconium alloys refer to alloys containing zirconium, magnesium alloys refer to alloys containing magnesium, titanium alloys refer to alloys containing titanium, and vanadium alloys refer to alloys containing vanadium.

[0245] In some embodiments of this application, the titanium alloy includes at least one of TiNi, Ti2Ni, TiFe, or TiMn2. The above-mentioned titanium alloy has excellent hydrogen absorption capacity, which can absorb hydrogen gas generated by the battery, reduce the internal pressure of the alkali metal battery, reduce the risk of thermal runaway of the alkali metal battery, and extend the life of the alkali metal battery.

[0246] In some embodiments of this application, the magnesium alloy includes at least one of Mg2Ni, Mg2Cu, Mg2Co, Mg2Al, Mg2Cr or Mg2Te. The above-mentioned magnesium alloy has excellent hydrogen absorption capacity, which can absorb hydrogen gas generated by the battery, reduce the internal pressure of the alkali metal battery, reduce the risk of thermal runaway of the alkali metal battery, and extend the life of the alkali metal battery.

[0247] In some embodiments of this application, the zirconium alloy includes at least one of ZrV2, ZrCr2, or ZrMn2. The aforementioned zirconium alloy has excellent hydrogen absorption capacity, which can absorb hydrogen gas generated by the battery, reduce the internal pressure of the alkali metal battery, reduce the risk of thermal runaway of the alkali metal battery, and extend the life of the alkali metal battery.

[0248] In some embodiments of this application, vanadium-based alloys include V3TiNi. 0.56 M1 m The vanadium alloy with the above chemical formula has excellent hydrogen absorption capacity. It can absorb hydrogen gas generated by the battery, reduce the internal pressure of the alkali metal battery, reduce the risk of thermal runaway of the alkali metal battery, and extend the life of the alkali metal battery.

[0249] In some embodiments of this application, the hydrogen storage metal includes LaNi. 3.5 M2 x1 M3 y1 M4 z1Where x1 is 0.2-0.6, y1 is 0-1, z1 is 0.3-0.9, x1+y1+z1=1.5, M2 includes at least one of Mn or Fe, M3 includes at least one of Zr, Ti or Y, and M4 includes at least one of Al, Mg, Ca or Bi.

[0250] As an example, x1 can be 0.2-0.59, 0.3-0.5, 0.4-0.45, etc., y1 can be 0-0.9, 0.1-0.8, 0.2-0.7, 0.3-0.6, 0.4-0.5, etc., and z1 can be 0.3-0.8, 0.4-0.7, 0.5-0.6, etc.

[0251] Specifically, lanthanide alloys have stable crystal structures and do not undergo other side reactions when reacting with hydrogen. Furthermore, the differences in atomic radii and electronegativity of different elements in the aforementioned hydrogen storage metals affect the unit cell volume of the hydrogen storage metal and the interaction force between hydrogen and metal atoms. Based on the differences in atomic radii and electronegativity of different elements, and through the combined action with transition metal atoms, the embodiments of this application can increase the hydrogen absorption capacity of the hydrogen storage metal, reduce the initial hydrogen absorption pressure, and improve the hydrogen release kinetics performance.

[0252] As an example, doping with transition metal M2 can reduce the hysteresis of hydrogen storage metals, while M3 and M4 can reduce the hydrogen absorption pressure of hydrogen storage metals, making it easier for them to absorb hydrogen. For instance, the doping element Ti has a particularly significant effect on improving the activation performance of hydrogen storage metals because Ti reacts with hydrogen before other phases during activation to form the TiH2 phase, causing cracks in the hydrogen storage metal and making it easier for hydrogen to enter the interior, effectively reducing the activation energy of the hydrogen storage metal. Through the combined effect of the above elements, the hydrogen storage capacity of the alloy can be increased, the initial hydrogen absorption pressure can be reduced, and the hydrogen release kinetics can be improved, making it easier for the hydrogen storage metal to absorb hydrogen and less likely to release it. This reduces the hydrogen content in the alkali metal battery, lowers the internal pressure of the alkali metal battery, and extends the battery's lifespan.

[0253] In some embodiments of this application, the hydrogen storage metal includes La. 0.5 Ni 4.5 Y 0.5 LaNi 3.5 Mn 0.2 YBi 0.3 LaNi 3.5 Mn 0.6 Y 0.4 Bi 0.5 LaNi 3.5 Mn 0.2 Y 0.4 Bi 0.9 LaTi 3.5 Fe 0.4 Zr0.5 Bi 0.6 LaTi 3.5 Fe 0.4 Zr 0.5 Mg 0.6 LaNi 4.26 Al 0.08 Mg 0.16 Or La 0.43 Y 0.57 Ni 4.5 Al 0.08 Mn 0.3 At least one of the above-mentioned hydrogen storage metals. The aforementioned hydrogen storage metals have excellent hydrogen storage capacity, low hydrogen absorption plateau pressure and high hydrogen release plateau pressure, which can effectively absorb hydrogen generated during the cycling process of alkali metal batteries, reduce the internal pressure of alkali metal batteries, and extend the life of alkali metal batteries.

[0254] Specifically, among the aforementioned hydrogen storage metals, at least one of Y or Fe elements is used, which can reduce the hydrogen absorption plateau pressure of the hydrogen storage metal. The molar ratio of La-site elements to other elements is less than 1:5. The high content of La-site elements results in a large amount of hydrogen absorption and a lower hydrogen absorption plateau pressure for the hydrogen storage metal.

[0255] This application does not limit the preparation method of the above-mentioned hydrogen storage metal. As an example, the preparation method of the above-mentioned hydrogen storage metal may be: mixing the metal elements corresponding to each element of the hydrogen storage metal in the molar ratio shown in the chemical formula, heating and melting under air-isolated conditions, and cooling to obtain the hydrogen storage metal.

[0256] Example 1

[0257] Preparation of hydrogen storage alloys:

[0258] Rare earth metals La, Ni, Mn, Y, and Bi were selected.

[0259] According to the molar ratio, the weighed bulk metal was placed in a zirconia crucible according to the designed process. The vacuum induction melting furnace was evacuated to a vacuum level of 1×10⁻³ Pa or higher before heating; then, argon gas at 0.05 MPa was introduced into the furnace as a protective gas; the heating temperature was adjusted to 1500℃; the liquid alloy was held at the molten state for 5 minutes; then, the uniformly mixed liquid metal was poured into a copper mold, cooled to room temperature in the furnace, and removed to obtain the master alloy ingot LaNi. 3.5 Mn 0.2 YBi 0.3 The hydrogen storage alloy has a volume average particle size (Dv50) of 10 μm, a BET specific surface area of ​​1 g / cm2, a pH of 10 in its saturated aqueous solution at 25℃, a tap density of 5 g / cm3, and a compaction density of 6 g / cm3.

[0260] The hydrogen storage alloy and the binder polytetrafluoroethylene (PTFE) were mixed at a mass ratio of 95:5, deionized water was added and stirred to disperse and form a slurry. The slurry was then coated onto a 20μm thick copper foil. After both sides were coated, the foil was dried, cold-pressed, slit, and sheeted to obtain a 100mm×20mm hydrogen storage alloy sheet (total thickness of 1.02mm, with a single-sided hydrogen storage alloy layer thickness of 0.5mm).

[0261] 1. Preparation of positive electrode sheet

[0262] Sodium-ion battery positive electrode active material (sodium iron pyrophosphate, residual alkali content of 0.5%), conductive agent (conductive carbon black), and binder (polyvinylidene fluoride) are mixed in a ratio of 90:5:5. Then, solvent (N-methylpyrrolidone, NMP) is added and stirred to disperse the mixture, thus preparing a positive electrode slurry. The positive electrode slurry is then coated onto Al foil using a double-sided, double-cavity coating device. After double-sided coating, the coating is dried, cold-pressed, slit, and the positive electrode sheet is obtained.

[0263] 2. Preparation of negative electrode sheet

[0264] Conductive carbon nanotubes and binder sodium carboxymethyl cellulose were added to water to form a slurry. The slurry was coated on a Cu foil with a thickness of 13 μm to form an interface modification layer, which was used as a Na deposition current collector. The single-sided coating thickness of the interface modification layer was 3 μm.

[0265] 3. Preparation of electrolyte

[0266] In an argon-filled glove box with a water content of <1ppm, NaPF6 was added to ethylene glycol dimethyl ether and stirred until homogeneous, resulting in an electrolyte with a NaPF6 concentration of 1.0 mol / L.

[0267] 4. Separating membrane

[0268] A polyethylene film with a thickness of 12 μm.

[0269] 5. Preparation of secondary batteries

[0270] The positive electrode, separator, and negative electrode are stacked in sequence, with the separator positioned between the anode and cathode to provide isolation. The electrode assembly 20 is then wound up and placed in the housing 11. Simultaneously, a hydrogen-absorbing alloy sheet is fixed to the underside of the top cover, adjacent to the tab, occupying the lower plastic position. After drying, electrolyte is injected at a rate of 4 g / Ah, leaving a residual space of 0.3 mL / Ah inside the housing 11. After formation and settling processes, a secondary battery is produced through further assembly, electrolyte injection, formation aging, and other steps.

[0271] The preparation methods of sodium-ion batteries in Examples 2-22 and Comparative Examples 1-3 are the same as those in Example 1, except that the process of preparing the hydrogen storage alloy is different. Examples 2-5 and 7-8 are adjusted according to the different elements and ratios of the hydrogen storage alloy compared to Example 1, as shown in Table 1.

[0272] In Comparative Example 1, no hydrogen storage alloy is prepared, and no hydrogen storage alloy is set in the secondary battery. In Comparative Example 2, the hydrogen absorption platform pressure of the hydrogen storage alloy set in the battery is not within the scope of this application. In Comparative Example 3, the residual space inside the shell 11 is not within the scope of this application.

[0273] Table 1

[0274] In Table 1, the hydrogen absorption pressure refers to the pressure at which the hydrogen storage alloy begins to absorb hydrogen, which is the minimum hydrogen absorption pressure.

[0275] The pressure-concentration isotherm (PCT) curve of the hydrogen storage alloy prepared in Example 1 was measured twice, with parallel sample 1 and parallel sample 2 used for the two measurements. The detailed test procedures for the two measurements are as follows:

[0276] The following measurements were taken using the H2PCT-1153 3-channel fully automated hydrogen storage material performance testing system (Yangzhou Yinghui Zhiyue):

[0277] Pressure sensors: 2 full-range absolute pressure sensors (0-10MPa) and 1 sensor (0-15MPa), with an accuracy of 0.04%FS; Temperature sensors: RT-100℃, RT-300℃, RT-500℃; The furnace can be programmed to heat up; The temperature sensors are placed outside the sample chamber; The sample chamber volume is (H15mm×12mm); The sample chamber and test pipeline are connected via quick connectors.

[0278] PCT curves and hydrogen absorption / desorption kinetics tests were conducted on the hydrogen storage material. The gas cylinders had capacities of three 1000ml cylinders and three 150ml cylinders. The entire pipeline could withstand a hydrogen pressure of 1×10⁻⁶-15 MPa. An Edwards vacuum pump (equipped with a flexible hose and exhaust gas vented outdoors) was used. The test results are shown in Figure 16. It can be seen that the hydrogen absorption plateau pressure of the hydrogen storage alloy in Example 1 is 0.2 MPa, and the minimum hydrogen absorption pressure is 0.008 MPa.

[0279] The hydrogen storage alloy sheet prepared in Example 1 was subjected to ion polishing cross-sectional morphology (CP) image obtained by ZEISS Sigma300 scanning electron microscope, as shown in Figure 17. It can be seen that the hydrogen storage alloy sheet includes a substrate 101 and a hydrogen storage alloy layer 102 disposed on the substrate.

[0280] The internal pressure of the secondary batteries prepared in Example 1 and Comparative Example 1 was measured over time using the built-in pressure sensor, as shown in Figure 18. It can be seen that the internal pressure of the battery in Example 1 of this application is always below 0.1 MPa, which is at a low level, while the internal pressure of the battery in Comparative Example 1, which did not add hydrogen storage alloy, increased significantly over time.

[0281] The internal pressure of gas generation and thermal runaway performance of the secondary batteries of Examples 1-22 and Comparative Examples 1-3 were characterized, and the characterization results are shown in Table 2.

[0282] 1. Cyclic Gas Generation Internal Pressure Test: Arrange the pipes along the sealing nail welding holes of the secondary battery prepared above. The pipe diameter is the same as that of the sealing nail holes. Connect the oil gauge along the end of the pipe. Clamp the battery with two aluminum plates. Set the initial clamping force to 3000N. Calibrate three times, with an interval of 15 minutes between each time. Then charge and discharge the battery at 1C / 1C. The temperature of all battery bodies should be monitored and the oil gauge pressure should be recorded.

[0283] 2. Thermal runaway performance test:

[0284] (1) Before testing, fully charge the secondary battery according to the following procedure: charge to 4V at 0.33C.

[0285] (2) Record the battery's main voltage, internal resistance, and weight; inspect the appearance and take photos.

[0286] (3) Place the secondary battery in a high-temperature chamber using a 15mm steel clamp, raise the temperature from RT to 100℃ at 5℃ / min and hold for 1 hour, then raise the temperature at 5℃ / min until the battery body runs out of control, and hold for 30 minutes at 5℃ every 30 minutes.

[0287] (4) Monitoring video, voltage of the battery body, temperature of the positive terminal, negative terminal, center of the large surface, barcode of the battery body, and explosion-proof port.

[0288] (5) Measure the voltage, internal resistance, and weight; inspect the appearance and take photos.

[0289] (6) Provide an experimental report. If the secondary battery does not catch fire or explode, it passes the thermal runaway test. The results are shown in Table 2.

[0290] Table 2

[0291] As shown in Table 2, in Examples 1-22 of this application, by adding a specific hydrogen storage metal to the alkali metal battery based on the pressure, residual space, and partial pressure of hydrogen within the casing 11, the internal pressure of the alkali metal battery can be reduced, thus lowering the risk of thermal runaway. Compared to Examples 1-22, the alkali metal battery in Comparative Example 1 does not use a hydrogen storage metal, the hydrogen absorption platform pressure of the hydrogen storage metal in the battery of Comparative Example 2 is outside the range of this application, and the residual space inside the casing 11 of Comparative Example 3 is outside the range of this application. Therefore, the internal pressure of the alkali metal battery is higher, and the risk of thermal runaway is higher.

[0292] As shown in Figure 2, this application proposes a battery device 200, including: the battery cell 100 in the above embodiment.

[0293] As shown in Figure 3, this application provides an electrical device 300, including the battery device 200 in the above embodiment.

[0294] Other configurations and operations of the battery cell 100, battery device 200, and power consumption device 300 according to the embodiments of this application are known to those skilled in the art and will not be described in detail here.

[0295] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0296] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A battery cell, wherein, include: The outer casing has a first wall; An electrode assembly, the electrode assembly being housed within the housing; A pressure relief mechanism is disposed on the first wall. The pressure relief mechanism includes a weak part and a main body. The weak part is configured to be destroyed when the pressure inside the housing reaches a threshold. The main body is configured to rotate or detach relative to the first wall when the weak part is destroyed. An exhaust mechanism is disposed on the first wall, the exhaust mechanism includes an exhaust port that communicates with the interior and exterior of the housing, and at least a portion of the exhaust port is disposed on the body portion.

2. The battery cell according to claim 1, wherein, The weak part includes: a first weak part, wherein the main body is connected to the first wall, and the first weak part is provided inside the main body.

3. The battery cell according to claim 2, wherein, At least a portion of the vent is located within the body portion, and the weak portion is connected to the vent, or the weak portion is spaced apart from the vent.

4. The battery cell according to claim 3, wherein, The first weak portion is annular, and the first weak portion is arranged around the exhaust port, and / or the exhaust port is located outside the surrounding area of ​​the first weak portion.

5. The battery cell according to claim 4, wherein, The first weak portion is disposed around one or more of the vent holes.

6. The battery cell according to claim 3, wherein, The two ends of the first weak part are respectively connected to the two exhaust holes.

7. The battery cell according to claim 6, wherein, The two ends of the first weak part are connected to the two adjacent exhaust holes.

8. The battery cell according to claim 3, wherein, One end of the first weak portion is connected to the vent, and the other end of the first weak portion extends toward the connection area between the body portion and the first wall.

9. The battery cell according to claim 1, wherein, The weak part further includes a second weak part, wherein the connection area between the body part and the first wall is formed as the second weak part.

10. The battery cell according to claim 9, wherein, The vent is disposed within the body portion, and / or the vent is formed in the connection area between the body portion and the first wall.

11. The battery cell according to claim 10, wherein, The vent located within the body portion is spaced apart from the second weak portion, and the vent located in the connection area between the body portion and the first wall is connected to the second weak portion.

12. The battery cell according to any one of claims 1-11, wherein, The weak point can be any one of the following: weld, local break, or notch.

13. The battery cell according to claim 12, wherein, The weak part is constructed as a weld, and the weld penetration depth is 0.3mm to 0.5mm.

14. The battery cell according to any one of claims 1-13, wherein, There are multiple exhaust holes, and the number of exhaust holes is 3 to 10.

15. The battery cell of claim 14, wherein, The number of exhaust holes is 4 to 5.

16. The battery cell according to any one of claims 1-15, wherein, There are multiple vent holes, and the total vent area of ​​the multiple vent holes is S1. When the weak part is damaged, it rotates or detaches relative to the first wall to define a vent area located on the first wall. The area of ​​the vent area is S2, and satisfies: 0 < S1 / S2 < 0.

6.

17. The battery cell according to claim 16, wherein, The outer shell is cylindrical and includes an end cap and a housing. The end cap defines the first wall, and the area of ​​the first wall is S3, satisfying: 0 < S2 / S3 < 0.

3.

18. The battery cell according to claim 16, wherein, The outer shell is constructed as a prism, and the first wall is defined by any surface of the prism. The area of ​​the first wall is S4, and satisfies: 0 < S2 / S4 < 0.

1.

19. The battery cell according to any one of claims 1-18, wherein, The exhaust mechanism includes a waterproof and breathable membrane disposed on the side of the first wall facing the electrode assembly, and the orthographic projection contour of each exhaust hole facing the electrode assembly falls within the orthographic projection contour of the waterproof and breathable membrane facing the electrode assembly.

20. The battery cell according to claim 19, wherein, The orthographic projection of the waterproof and breathable membrane toward the electrode assembly is spaced apart from the orthographic projection of the weak portion toward the electrode assembly.

21. The battery cell according to any one of claims 1-20, wherein, The pressure relief mechanism is integrally formed with the first wall, or the pressure relief mechanism is assembled on the first wall.

22. The battery cell according to any one of claims 1-21, wherein, The battery cell is configured as an alkali metal battery.

23. The battery cell according to claim 22, wherein, The electrode assembly includes a negative electrode sheet, the negative electrode sheet includes a negative current collector and an active material layer disposed on at least one side of the negative current collector, the active material layer including an elemental active metal.

24. The battery cell according to claim 23, wherein, The active metal element includes at least one of lithium, sodium, potassium, zinc, or aluminum.

25. The battery cell according to any one of claims 1-24, wherein, The housing contains an electrolyte, the electrode assembly is immersed in the electrolyte, and the electrolyte includes a solvent configured as at least one of an ether solvent or an ester solvent.

26. The battery cell according to claim 25, wherein, The ether solvents include at least one of 1,2-dimethoxypropane, dimethoxymethane, ethylene glycol dimethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, pentaethylene glycol dimethyl ether, polyethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol diethyl ether, triethylene glycol diethyl ether, tetraethylene glycol diethyl ether, pentaethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dibutyl ether, or 1,3-dioxopentane.

27. The battery cell according to any one of claims 1-26, wherein, The outer casing contains a gas storage structure, at least a portion of which is a hydrogen storage metal, including zirconium alloys, magnesium alloys, titanium alloys, vanadium alloys, or La. x Ni y M z At least one of them, Wherein, M includes at least one of Zr, Mn, Mg, Zn, Al, Ti, Fe, Cu, Co, Y, Ca or Bi, 0 < x ≤ 2, 0 ≤ y ≤ 7, 0 ≤ z ≤ 3.

28. The battery cell according to claim 27, wherein, M includes at least one of Al, Mn, Mg, Fe, Y or Bi, and 0.3≤x≤1, 1≤y≤5, 0≤z≤1; The titanium alloy includes at least one of TiNi, Ti2Ni, TiFe, or TiMn2; The magnesium alloy includes at least one of Mg2Ni, Mg2Cu, Mg2Co, Mg2Al, Mg2Cr or Mg2Te; The zirconium alloy includes at least one of ZrV2, ZrCr2, or ZrMn2; The vanadium-based alloy includes V3TiNi. 0.56 M1 m m = 0.046-0.24, M1 includes at least one of Al, Si, Fe, Cu or Zr.

29. The battery cell according to claim 28, wherein, The hydrogen storage metal includes LaNi. 3.5 M2 x1 M3 y1 M4 z1 Where x1 is 0.2-0.6, y1 is 0-1, z1 is 0.3-0.9, x1+y1+z1=1.5, M2 includes at least one of Mn or Fe, M3 includes at least one of Zr, Ti or Y, and M4 includes at least one of Al, Mg, Ca or Bi.

30. The battery cell according to claim 28, wherein, The hydrogen storage metal includes: La 0.5 Ni 4.5 Y 0.5 LaNi 3.5 Mn 0.2 YBi 0.3 LaNi 3.5 Mn 0.6 Y 0.4 Bi 0.5 LaNi 3.5 Mn 0.2 Y 0.4 Bi 0.9 LaTi 3.5 Fe 0.4 Zr 0.5 Bi 0.6 LaTi 3.5 Fe 0.4 Zr 0.5 Mg 0.6 LaNi 4.26 Al 0.08 Mg 0.16 Or La 0.43 Y 0.57 Ni 4.5 Al 0.08 Mn 0.3 At least one of them.

31. A battery device, wherein, include: The battery cell according to any one of claims 1-30.

32. An electrical appliance, wherein, include: The battery device according to claim 31.

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