Battery cell, battery device and electric device

Abstract

The utility model discloses a battery monomer, a battery device and a power utilization device. The battery monomer comprises an electrode assembly, a shell and an end cover, the electrode assembly is arranged in the shell, and the shell is provided with an opening; the end cover covers the opening and comprises a cover body and a pressure relief mechanism, the cover body is provided with a liquid injection hole and a pressure relief hole located beside the liquid injection hole, the pressure relief mechanism comprises a pressure relief part and a detection part, the pressure relief part is arranged at the pressure relief hole, and the detection part is arranged on the side, away from the electrode assembly, of the pressure relief part. Potential safety hazards are reduced, and the reliability of the single battery is improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell, a battery device, and an electrical device. Background Art

[0002] In recent years, with the rapid development of new energy technologies, new energy vehicles have become increasingly popular, gradually replacing traditional fuel vehicles and becoming one of the mainstream modes of transportation. As the power source of new energy vehicles, power batteries are one of their core components, making their safety performance a key concern.

[0003] In the development of battery technology, how to improve the reliability of battery cells is a research direction in battery technology. Utility Model Content

[0004] Embodiments of the present application provide a battery cell, a battery device, and an electrical device, which can improve the reliability of the battery cell.

[0005] In the first aspect, an embodiment of the present application provides a battery cell, which includes an electrode assembly, a shell and an end cover, wherein the electrode assembly is arranged inside the shell, and the shell is provided with an opening; the end cover is provided at the opening, and the end cover includes a cover body and a pressure relief mechanism, the cover body is provided with a liquid injection hole and a pressure relief hole located next to the liquid injection hole, the pressure relief mechanism includes a pressure relief part and a detection part, the pressure relief part is provided at the pressure relief hole, and the detection part is provided on the side of the pressure relief part away from the electrode assembly.

[0006] In the above solution, when the electrolyte is injected into the shell through the injection hole, if the electrolyte overflows and contaminates the pressure relief mechanism, since a detection part is provided on the side of the pressure relief part away from the electrode assembly, the detection part can detect the overflow of the electrolyte, thereby improving the reliability of the battery cell.

[0007] In some embodiments, the detection portion is arranged in the edge area of ​​the pressure relief portion near the pressure relief hole, which improves the accuracy of detecting whether the pressure relief mechanism is contaminated by the electrolyte. When the air pressure inside the shell is too high, it is also convenient for the gas to break through the weak area in the middle of the pressure relief mechanism and release the gas inside the shell.

[0008] In some embodiments, the detection portion is arranged in a surrounding manner along the circumference of the pressure relief hole, thereby increasing the detection range for detecting whether the pressure relief mechanism is contaminated by the electrolyte.

[0009] In some embodiments, at least a portion of the detection portion is disposed at a position of the pressure relief portion close to the liquid injection hole, thereby improving the accuracy of detecting whether the pressure relief mechanism is contaminated by the electrolyte.

[0010] In some embodiments, the detection portion includes a first detection section and a second detection section that are arranged opposite to each other. The first detection section is arranged on the side of the pressure relief portion close to the liquid injection hole, and the second detection section is arranged on the side of the pressure relief portion away from the liquid injection hole. The area of ​​the first detection section is larger than the area of ​​the second detection section.

[0011] In the above scheme, the first detection section is more susceptible to electrolyte contamination than the second detection section. Therefore, setting the area of ​​the first detection section larger than that of the second detection section can further improve the accuracy of detecting whether the pressure relief mechanism is contaminated by the electrolyte.

[0012] In some embodiments, the pressure relief portion includes a pressure relief section and a fixed section, the pressure relief section covers the pressure relief hole, and the detection portion is arranged on the side of the pressure relief portion away from the electrode assembly; the fixed section is arranged on the periphery of the pressure relief section, and the fixed section is connected to the cover body.

[0013] In the above solution, the fixing section located at the periphery of the pressure relief section is connected to the cover body, thereby improving the connection stability between the pressure relief mechanism and the cover body.

[0014] In some embodiments, the area of ​​the detection portion is S1, and the area of ​​the pressure relief section is S2. S1 and S2 satisfy: 0.1≤S1 / S2≤1. This can not only improve the detection efficiency of whether the pressure relief mechanism is contaminated by the electrolyte to a certain extent, but also does not affect the pressure relief mechanism being destroyed when the air pressure inside the shell is too high, thereby removing the gas inside the shell.

[0015] In some embodiments, S1 and S2 satisfy: 0.5≤S1 / S2≤1, further improving the efficiency of detecting whether the pressure relief mechanism is contaminated by the electrolyte.

[0016] In some embodiments, the thickness of the detection portion is D, and D satisfies: 0.1 μm≤D≤200 μm.

[0017] In the above scheme, the thickness of the detection part is within a reasonable range, which can not only improve the detection efficiency of whether the pressure relief mechanism is contaminated by the electrolyte to a certain extent, but also does not affect the pressure relief mechanism being destroyed when the air pressure inside the shell is too high, thereby removing the gas inside the shell.

[0018] In some embodiments, D satisfies: 5 μm≤D≤20 μm, which further improves the efficiency of detecting whether the pressure relief mechanism is contaminated by the electrolyte and further ensures the pressure relief function of the pressure relief mechanism.

[0019] In some embodiments, the pressure relief mechanism further includes a protection portion, which is disposed on a side of the detection portion facing away from the electrode assembly, and covers the pressure relief portion.

[0020] In the above solution, the protection part can reduce the risk of the pressure relief mechanism being contaminated by the outside world.

[0021] In a second aspect, an embodiment of the present application further provides a battery device comprising the above-mentioned battery cell.

[0022] In a third aspect, an embodiment of the present application further provides an electrical device, comprising the above-mentioned battery device, which is used to provide electrical energy.

[0023] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 A schematic structural diagram of a vehicle according to some embodiments of the present application;

[0026] Figure 2 An exploded view of a battery device according to some embodiments of the present application;

[0027] Figure 3 This is a schematic structural diagram of a battery module according to some embodiments of the present application;

[0028] Figure 4 This is a schematic diagram of the exploded structure of a battery cell according to some embodiments of the present application;

[0029] Figure 5 is a schematic structural diagram of the end caps of some embodiments of the present application;

[0030] Figure 6 Schematic diagrams of the structures of end covers of other embodiments of the present application;

[0031] Figure 7 is a schematic structural diagram of a pressure relief mechanism in some embodiments of the present application;

[0032] Figure 8 It is a schematic structural diagram of the end cover of some other embodiments of the present application.

[0033] Description of reference numerals:

[0034] 1000, vehicle; 100, battery device; 200, controller; 300, motor; 10, upper cover; 30, housing; 400, battery module; 20, battery cell; 22, housing; 21, end cap; 23, electrode assembly; 40, cover body; 41, liquid injection hole; 42, pressure relief hole; 43, top cover; 44, insulating part; 50, pressure relief mechanism; 51, pressure relief part; 511, pressure relief section; 512, fixing section; 52, detection part; 521, first detection section; 522, second detection section; 60, protection part. DETAILED DESCRIPTION

[0035] The following detailed description of the embodiments of the present application is provided in conjunction with the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of the present application, but are not intended to limit the scope of the present application, that is, the present application is not limited to the described embodiments.

[0036] In the description of this application, it should be noted that, unless otherwise specified, "multiple" means more than two; the terms "upper", "lower", "left", "right", "inside", "outside", etc., indicating directions or positional relationships, 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 direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on this application. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not strictly perpendicular, but is within the allowable error range. "Parallel" is not strictly parallel, but is within the allowable error range.

[0037] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0038] The directional words appearing in the following description are all directions shown in the figures, and do not limit the specific structure of this application. In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0039] In this application, battery cells may include lithium-ion secondary battery cells, lithium-ion primary battery cells, lithium-sulfur battery cells, sodium-lithium-ion battery cells, sodium-ion battery cells, or magnesium-ion battery cells, etc., and the embodiments of this application do not limit this. Battery cells may be cylindrical, flat, rectangular, or other shapes, etc., and the embodiments of this application do not limit this. Battery cells are generally divided into three types according to the packaging method: cylindrical battery cells, square battery cells, and soft-pack battery cells, and the embodiments of this application do not limit this.

[0040] The battery device mentioned in the embodiments of the present application may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include multiple battery cells, which are connected in series, parallel, or hybrid via a busbar.

[0041] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells. For example, the battery cell assembly may be a battery module, which is formed by arranging and securing multiple battery cells to form a single module. For example, a battery module may be formed by bundling multiple battery cells using cable ties.

[0042] In some embodiments, the battery device may be a battery pack, which includes a case and one or more battery cell assemblies, wherein the battery cell assemblies are housed in the case.

[0043] As an example, the battery cell assembly may be a battery module, and the battery cell assembly may be accommodated in the box by fixing the battery module in the box.

[0044] As an example, the battery cell assembly may also be housed in the box by directly fixing the plurality of battery cells to the box.

[0045] The present invention provides an electric device that uses a battery as a power source. The electric device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery-powered vehicle, an electric car, a ship, a spacecraft, etc. The electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc. The spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0046] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application.

[0047] Please refer to Figure 1 , Figure 1Schematic diagram of the structure of the vehicle provided for some embodiments of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery device 100 is provided inside the vehicle 1000, and the battery device 100 can be provided at the bottom, head or tail of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000. For example, the battery device 100 can serve as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0048] In some embodiments of the present application, the battery device 100 can serve not only as an operating power source for the vehicle 1000 , but also as a driving power source for the vehicle 1000 , replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000 .

[0049] Please refer to Figure 2 , Figure 2 Exploded diagram of the device provided in some embodiments of the present application. The battery device 100 includes a battery case and a battery cell 20. In some embodiments, the battery case may include an upper cover 10 and a case 30, the upper cover 10 and the case 30 covering each other, and the upper cover 10 and the case 30 jointly define a receiving cavity for accommodating the battery cell 20. The case 30 may be a hollow structure with one end open, and the upper cover 10 may be a plate-like structure, the upper cover 10 covering the open side of the case 30, so that the upper cover 10 and the case 30 jointly define a receiving cavity; the upper cover 10 and the case 30 may also be hollow structures with one side open, the open side of the upper cover 10 covering the open side of the case 30. Of course, the battery case formed by the upper cover 10 and the case 30 may be in various shapes, such as a cylinder, a cuboid, etc.

[0050] Figure 3 This is a schematic diagram of the structure of the battery module of some embodiments of the present application. In the battery device 100, there can be multiple battery cells 20, and the multiple battery cells 20 can be connected in series, in parallel, or in mixed connection. Mixed connection means that the multiple battery cells 20 are both connected in series and in parallel. The multiple battery cells 20 can be directly connected in series, in parallel, or in mixed connection, and then the whole formed by the multiple battery cells 20 is accommodated in the box; of course, the battery device 100 can also be a battery module formed by connecting multiple battery cells 20 in series, in parallel, or in mixed connection, and then the multiple battery modules are connected in series, in parallel, or in mixed connection to form a whole, and accommodated in the box. The battery device 100 can also include other structures. For example, the battery device 100 can also include a busbar component for realizing electrical connection between the multiple battery cells 20.

[0051] Each battery cell 20 may be a secondary battery cell or a primary battery cell; it may also be a lithium-sulfur battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, but is not limited thereto. The battery cell 20 may be cylindrical, flat, rectangular, or in other shapes.

[0052] Please refer to Figure 4 , Figure 4 Schematic diagram of the exploded structure of a battery cell provided in some embodiments of the present application. A battery cell 20 is the smallest unit that makes up a battery. A battery cell 20 includes an end cap 21, a housing 22, an electrode assembly 23, and other functional components.

[0053] The end cap 21 is a component that covers the opening of the housing 22 to isolate the internal environment of the battery cell 20 from the external environment. The shape of the end cap 21 can be adapted to the shape of the housing 22 to fit the housing 22. Optionally, the end cap 21 can be made of a material with a certain hardness and strength (such as an aluminum alloy). This prevents the end cap 21 from deforming when subjected to compression or collision, thereby providing the battery cell 20 with greater structural strength and improved safety. Functional components such as electrode terminals 26 can be provided on the end cap 21. The electrode terminals 26 can be used to electrically connect to the electrode assembly 23 to output or input electrical energy to the battery cell 20. In some embodiments, the end cap 21 can also be provided with a pressure relief mechanism for relieving internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold. The end cap 21 can also be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this embodiment of the present application does not impose any specific limitations on this. In some embodiments, an insulating member may be provided inside the end cap 21 to isolate the electrical connection components in the housing 22 from the end cap 21 to reduce the risk of short circuit. For example, the insulating member may be made of plastic, rubber, or the like.

[0054] The electrolyte is a crucial component of a battery cell. It's typically injected into the housing through the injection holes on the end caps, allowing the electrolyte to penetrate the electrodes, participate in chemical reactions, and convert chemical energy into electrical energy. At the same time, a pressure relief mechanism is also provided on the end caps. If thermal runaway occurs inside the housing of the battery cell and the air pressure becomes excessive, the pressure relief mechanism will be damaged and open, releasing the gas inside the housing. If the electrolyte overflows into the pressure relief mechanism during the injection process, it can pose a significant safety hazard later on, reducing the reliability of the battery cell.

[0055] In order to solve the above technical problems, an embodiment of the present application provides a battery cell, which includes an electrode assembly, a shell and an end cover. The electrode assembly is arranged inside the shell, and the shell is provided with an opening; the end cover is provided at the opening, and the end cover includes a cover body and a pressure relief mechanism. The cover body is provided with an injection hole and a pressure relief hole located next to the injection hole. The pressure relief mechanism includes a pressure relief part and a detection part. The pressure relief part is provided at the pressure relief hole, and the detection part is provided on the side of the pressure relief part away from the electrode assembly.

[0056] In the above solution, when the electrolyte is injected into the shell through the injection hole, if the electrolyte overflows and contaminates the pressure relief mechanism, since a detection part is provided on the side of the pressure relief part away from the electrode assembly, the detection part can detect the overflow of the electrolyte, thereby improving the reliability of the battery cell.

[0057] Figure 5 It is a schematic structural diagram of the end cover of some embodiments of the present application.

[0058] like Figure 5 As shown, in the first aspect, an embodiment of the present application provides a battery cell 20, which includes an electrode assembly 23, a shell 22 and an end cover 21. The electrode assembly 23 is arranged inside the shell 22, and the shell 22 is provided with an opening; the end cover 21 is covered at the opening, and the end cover 21 includes a cover body 40 and a pressure relief mechanism 50. The cover body 40 is provided with a liquid injection hole 41 and a pressure relief hole 42 located next to the liquid injection hole 41. The pressure relief mechanism 50 includes a pressure relief part 51 and a detection part 52. The pressure relief part 51 is arranged at the pressure relief hole 42, and the detection part 52 is arranged on the side of the pressure relief part 51 away from the electrode assembly 23.

[0059] The cover body 40 may include a top cover 43 and an insulating member 44 . The insulating member 44 is disposed on a side of the top cover 43 facing the housing 22 , and the dripping pipe is disposed on a side of the insulating member 44 facing the housing 22 . The insulating member 44 may reduce the risk of short circuit.

[0060] The pressure relief hole 42 is provided on the top cover 43 of the cover body 40, and the insulating member 44 is also provided with a through hole at a position corresponding to the pressure relief hole 42. When thermal runaway occurs inside the battery cell 20 and the air pressure is too high, the pressure relief mechanism 50 can be opened to allow the gas inside the battery cell 20 to be discharged. Specifically, a notch can be provided on the pressure relief portion 51. The notch is thinner than other parts, so the position of the notch is easier to break, and the high-pressure gas can destroy the notch position, thereby releasing the gas inside the shell 22. Alternatively, the material of certain areas of the pressure relief portion 51 can be set to be more easily destroyed, so that the gas inside the shell 22 is released after this area is destroyed by the high-pressure gas.

[0061] The detection portion 52 can be formed by coating the side of the pressure relief portion 51 facing away from the electrode assembly 23. The detection portion 52 is a coating layer, which can be applied by spraying or spin coating. Alternatively, the detection portion 52 can be directly attached to the side of the pressure relief portion 51 facing away from the electrode assembly 23. The detection portion 52 can cover the entire area of ​​the pressure relief portion 51, or it can cover a portion of the area. The detection portion 52 can be in an arc shape or other polygonal shape.

[0062] The material of the detection portion 52 may include conjugated molecules. For example, the detection portion 52 includes conjugated molecules having double bonds, triple bonds or aromatic rings such as styrenes, phenylacetylenes, and azos, and the molecular weight is generally less than 1000. The solvent of the electrolyte is generally one or more of dimethyl carbonate and diethyl carbonate. The above-mentioned conjugated molecules can be dissolved in the solvent of the above-mentioned electrolyte, and the dissolved solution emits light under ultraviolet light (including purple light, blue light, green light, yellow light, orange light or red light, etc.). Alternatively, the material containing the conjugated molecules is solid when not contaminated by the electrolyte, and is liquid after being dissolved in the electrolyte. The liquid or solid state exhibits different luminous colors under ultraviolet light. For example, biphenyl is dissolved in tetrahydrofuran to form a compound solution, which is then spin-coated or sprayed on the side of the pressure relief portion 51 facing away from the electrode assembly 23 to form a layered detection portion 52; when the pressure relief mechanism is contaminated by electrolyte, the biphenyl in the detection portion 52 dissolves in the electrolyte, emits light under ultraviolet light, and is then detected.

[0063] In the above scheme, when the electrolyte is injected into the shell 22 through the injection hole 41, if the electrolyte overflows and contaminates the pressure relief mechanism 50, since the detection part 52 is provided on the side of the pressure relief part 51 away from the electrode assembly 23, the detection part 52 can detect the overflow of the electrolyte, thereby improving the reliability of the battery cell 20.

[0064] In some embodiments, the detection portion 52 is disposed at an edge region of the pressure relief portion 51 close to the pressure relief hole 42 .

[0065] The detection portion 52 may be provided along the entire periphery of the entire pressure relief portion 51 , or may be provided in a partial edge region.

[0066] Generally, the edge area of ​​the pressure relief portion 51 is more easily contaminated by the electrode liquid than the middle area, and the middle area of ​​the pressure relief portion 51 is weaker than the edge area. When the battery cell 20 experiences thermal runaway, the middle area of ​​the pressure relief portion 51 is more easily damaged than the edge area.

[0067] In the above scheme, by setting the detection part 52 in the edge area of ​​the pressure relief part 51 close to the pressure relief hole 42, the accuracy of detecting whether the pressure relief mechanism 50 is contaminated by the electrolyte is improved, and when the air pressure inside the shell 22 is too high, it is also convenient for the gas to break through the weak area in the middle of the pressure relief mechanism 50 and release the gas inside the shell 22.

[0068] In some embodiments, the detection portion 52 is disposed around the circumference of the pressure relief hole 42 , thereby increasing the detection range for detecting whether the pressure relief mechanism 50 is contaminated by the electrolyte.

[0069] Figure 6 It is a schematic structural diagram of the end cover of other embodiments of the present application.

[0070] like Figure 6 As shown, in some embodiments, at least a portion of the detection portion 52 is disposed at a position of the pressure relief portion 51 close to the liquid injection hole 41 .

[0071] When the electrolyte is injected into the liquid injection hole 41 , the position of the pressure relief portion 51 close to the liquid injection hole 41 is more easily contaminated by the overflowing electrolyte.

[0072] In the above solution, by arranging at least a portion of the detection portion 52 at a position close to the liquid injection hole 41 , the accuracy of detecting whether the pressure relief mechanism 50 is contaminated by the electrolyte is improved.

[0073] In some embodiments, the detection portion 52 includes a first detection section 521 and a second detection section 522 that are arranged opposite to each other. The first detection section 521 is arranged on the side of the pressure relief portion 51 close to the liquid injection hole 41, and the second detection section 522 is arranged on the side of the pressure relief portion 51 away from the liquid injection hole 41. The area of ​​the first detection section 521 is larger than the area of ​​the second detection section 522.

[0074] The first detection section 521 is closer to the injection hole 41 than the second detection section 522 . When the electrolyte is injected into the injection hole 41 , the first detection section 521 is more easily contaminated by the overflowed electrolyte.

[0075] In the above scheme, the first detection section 521 is more susceptible to electrolyte contamination than the second detection section 522. Therefore, setting the area of ​​the first detection section 521 to be larger than the area of ​​the second detection section 522 can further improve the accuracy of detecting whether the pressure relief mechanism 50 is contaminated by the electrolyte.

[0076] Figure 7 It is a structural schematic diagram of the pressure relief mechanism of some embodiments of the present application.

[0077] like Figure 7 As shown, in some embodiments, the pressure relief portion 51 includes a pressure relief section 511 and a fixed section 512, the pressure relief section 511 covers the pressure relief hole 42, and the detection portion 52 is arranged on the side of the pressure relief portion 51 away from the electrode assembly 23; the fixed section 512 is arranged on the periphery of the pressure relief section 511, and the fixed section 512 is connected to the cover body 40.

[0078] The fixing section 512 can be connected to the cover body 40 by means of snaps, bolts, or bonding. The fixing section 512 can be arranged around the outer circumference of the pressure relief section 511, or multiple fixing sections 512 can be provided around the outer circumference of the pressure relief section 511, and the multiple fixing sections 512 are arranged at intervals along the circumference of the pressure relief section 511.

[0079] In the above solution, the fixing section 512 located on the periphery of the pressure relief section 511 is connected to the cover body 40 , thereby improving the connection stability between the pressure relief mechanism 50 and the cover body 40 .

[0080] In some embodiments, the area of ​​the detection portion 52 is S1, the area of ​​the pressure relief section 511 is S2, and S1 and S2 satisfy: 0.1≤S1 / S2≤1.

[0081] Wherein, S1 / S2 can be any value between 0.1 and 1. For example, S1 / S2 can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, etc.

[0082] In the above scheme, S1 / S2 is within a reasonable range, which can not only improve the detection efficiency of whether the pressure relief mechanism 50 is contaminated by the electrolyte to a certain extent, but also does not affect the pressure relief mechanism 50 being destroyed when the air pressure inside the shell 22 is too high, thereby removing the gas inside the shell 22.

[0083] In some embodiments, S1 and S2 satisfy: 0.5≤S1 / S2≤1.

[0084] Wherein, S1 / S2 can be any value between 0.5 and 1. For example, S1 / S2 can be 0.5, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1, etc.

[0085] In the above solution, by further limiting the range of S1 / S2, the efficiency of detecting whether the pressure relief mechanism 50 is contaminated by the electrolyte is further improved.

[0086] In some embodiments, the thickness of the detection portion 52 is D, and D satisfies: 0.1 μm≤D≤200 μm.

[0087] The thickness of the detection portion 52 may be any value between 0.1 μm and 200 μm. For example, the thickness D of the detection portion 52 may be 0.1 μm, 10 μm, 30 μm, 50 μm, 100 μm, 130 μm, 150 μm, 160 μm, 180 μm, 200 μm, etc.

[0088] In the above scheme, the thickness of the detection part 52 is within a reasonable range, which can not only improve the detection efficiency of whether the pressure relief mechanism 50 is contaminated by the electrolyte to a certain extent, but also does not affect the pressure relief mechanism 50 being destroyed when the air pressure inside the shell 22 is too high, thereby removing the gas inside the shell 22.

[0089] In some embodiments, D satisfies: 5 μm≤D≤20 μm.

[0090] The thickness of the detection portion 52 may be any value between 5 μm and 20 μm. For example, the thickness D of the detection portion 52 may be 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 12 μm, 14 μm, 16 μm, 20 μm, etc.

[0091] In the above solution, by further limiting the range of the thickness D of the detection portion 52 , the efficiency of detecting whether the pressure relief mechanism 50 is contaminated by the electrolyte is further improved, and the pressure relief function of the pressure relief mechanism 50 is further ensured.

[0092] Figure 8 It is a schematic structural diagram of the end cover of some other embodiments of the present application.

[0093] like Figure 8 As shown, in some embodiments, the pressure relief mechanism 50 further includes a protection portion 60 . The protection portion 60 is disposed on a side of the detection portion 52 facing away from the electrode assembly 23 . The protection portion 60 covers the pressure relief portion 51 .

[0094] The protection portion 60 may be a protection sheet or a protection thin plate, and the shape of the protection portion 60 is adapted to the shape of the pressure relief hole 42 .

[0095] In the above solution, the protection portion 60 can reduce the risk of the pressure relief mechanism 50 being contaminated by the outside world.

[0096] In a second aspect, an embodiment of the present application further provides a battery device 100 , comprising the above-mentioned battery cell 20 .

[0097] In a third aspect, an embodiment of the present application further provides an electrical device, comprising the above-mentioned battery device 100, wherein the battery device 100 is used to provide electrical energy.

[0098] According to some embodiments of the present application, a battery cell 20 is provided. The battery cell 20 includes an electrode assembly 23, a housing 22, and an end cap 21. The electrode assembly 23 is disposed inside the housing 22, which is provided with an opening. The end cap 21 covers the opening. The end cap 21 includes a cap body 40 and a pressure relief mechanism 50. The cap body 40 is provided with a liquid injection hole 41 and a pressure relief hole 42 located next to the liquid injection hole 41. The pressure relief mechanism 50 includes a pressure relief portion 51 and a detection portion 52. The pressure relief portion 51 is disposed at the pressure relief hole 42, and the detection portion 52 is disposed on a side of the pressure relief portion 51 away from the electrode assembly 23. The detection portion 52 is disposed at an edge area of ​​the pressure relief portion 51 near the pressure relief hole 42.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: include: electrode assembly; a shell, wherein the electrode assembly is disposed inside the shell, and the shell is provided with an opening; An end cover is provided at the opening, the end cover includes a cover body and a pressure relief mechanism, the cover body is provided with a liquid injection hole and a pressure relief hole located next to the liquid injection hole, the pressure relief mechanism includes a pressure relief part and a detection part, the pressure relief part is provided at the pressure relief hole, and the detection part is provided on the side of the pressure relief part away from the electrode assembly.

2. The battery cell according to claim 1, wherein: The detection portion is disposed in an edge area of ​​the pressure relief portion close to the pressure relief hole.

3. The battery cell according to claim 2, characterized in that: The detection portion is arranged in a surrounding manner along the circumference of the pressure relief hole.

4. The battery cell according to claim 1, wherein: At least a portion of the detection portion is disposed at a position of the pressure relief portion close to the liquid injection hole.

5. The battery cell according to claim 4, characterized in that The detection portion includes a first detection section and a second detection section arranged opposite to each other, the first detection section is arranged on a side of the pressure relief portion close to the liquid injection hole, and the second detection section is arranged on a side of the pressure relief portion away from the liquid injection hole, and the area of ​​the first detection section is larger than the area of ​​the second detection section.

6. The battery cell according to claim 1, characterized in that The pressure relief portion includes: a pressure relief section, covering the pressure relief hole, wherein the detection portion is arranged on a side of the pressure relief portion away from the electrode assembly; The fixing section is arranged on the outer periphery of the pressure relief section, and the fixing section is connected to the cover body.

7. The battery cell according to claim 6, characterized in that The area of ​​the detection portion is S1, the area of ​​the pressure relief section is S2, and S1 and S2 satisfy: 0.1≤S1 / S2≤1.

8. The battery cell according to claim 7, characterized in that The S1 and the S2 satisfy: 0.5≤S1 / S2≤1.

9. The battery cell according to claim 1, characterized in that The thickness of the detection portion is D, and D satisfies: 0.1 μm≤D≤200 μm.

10. The battery cell according to claim 9, characterized in that The D satisfies: 5 μm≤D≤20 μm.

11. The battery cell according to claim 1, wherein The pressure relief mechanism further includes a protection portion, which is arranged on a side of the detection portion away from the electrode assembly and covers the pressure relief portion.

12. A battery device, characterized in that: The invention comprises a battery cell according to any one of claims 1 to 11.

13. An electrical device, characterized in that: The battery device according to claim 12 is included, and is used to provide electrical energy.

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