Battery monomer, battery device and electric device

Abstract

The invention relates to the technical field of batteries, and provides a battery monomer, a battery device and a power utilization device. The battery cell comprises: a housing having an accommodating cavity; the electrode assembly is contained in the containing cavity, the electrode assembly comprises a positive plate, the positive plate comprises a positive current collector and a positive film layer arranged on the surface of the positive current collector, the positive film layer comprises a positive active material and a water removal agent, and the water removal agent can chemically react with water in the positive active material to generate gas; the shell is provided with a first wall, the first wall is provided with an exhaust hole, the exhaust assembly is arranged on the first wall and covers the exhaust hole, and the exhaust assembly is configured to be actuated to release internal gas under the condition that the gas pressure in the battery single body reaches a first preset threshold value. According to the technical scheme, the risk of deformation or damage of the battery monomer due to volume expansion can be reduced, and the use stability of the battery monomer can be improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to a battery cell, a battery device, and an electrical device. Background Technology

[0002] This section provides only background information relevant to this disclosure and is not necessarily prior art.

[0003] Currently, with the rapid development of new energy vehicles, battery devices are increasingly coming into the public eye.

[0004] A battery device typically has one or more battery cells. The operating environment of the battery device can affect the lifespan of the battery cells. For example, in a high-temperature environment, the electrochemical reaction rate within the battery cell will accelerate, leading to a decrease in capacity. Furthermore, the electrolyte within the battery cell will decompose and undergo side reactions, resulting in a shortened cycle life of the battery cell. Summary of the Invention

[0005] The purpose of this application is to provide a battery cell that improves the cycle life of the battery cell and reduces the risk of electrode assembly volume expansion, deformation, or damage. This purpose is achieved through the following technical solution:

[0006] In a first aspect, this application provides a battery cell, comprising: a housing having a receiving cavity; an electrode assembly housed within the receiving cavity, the electrode assembly including a positive electrode sheet, the positive electrode sheet including a positive current collector and a positive electrode film layer disposed on the surface of the positive current collector, the positive electrode film layer including a positive electrode active material and a dehydrating agent, the dehydrating agent being capable of chemically reacting with water in the positive electrode active material to generate gas; and an exhaust assembly, the housing having a first wall, the first wall having an exhaust hole, the exhaust assembly being disposed on the first wall and sealing the exhaust hole, the exhaust assembly being configured to be actuated to release internal gas when the gas pressure inside the battery cell reaches a first preset threshold.

[0007] According to the battery cell provided in this application, by adding a dehydrating agent to the positive electrode active material of the positive electrode film layer, the dehydrating agent can chemically react with the water in the positive electrode active material, thereby reducing the water in the electrolyte and reducing the hydrofluoric acid generated by the chemical reaction of lithium salt in the electrolyte, thus protecting the solid electrolyte interface inside the battery cell and improving the cycle life of the battery cell. Since the dehydrating agent produces gas, such as ammonia, when it chemically reacts with water in the positive electrode active material, this application further provides an exhaust vent on the first wall of the casing and an exhaust assembly on the outer side of the first wall. The exhaust assembly is actuated when the gas pressure inside the battery cell reaches a first preset threshold, thereby venting the gas inside the battery cell to the outside. This reduces the risk of deformation or even rupture of the electrode cell due to volume expansion caused by gas generation, thus improving the reliability of the battery cell.

[0008] In addition, the battery cell provided in this application may also have the following additional technical features:

[0009] In some embodiments of this application, the venting assembly includes: a valve cover disposed on the side of the first wall away from the electrode assembly and covering the vent hole, wherein the valve cover has at least one venting portion; a first stop member disposed in contact with the inner circumferential surface of the valve cover and connected to the first wall, wherein the first stop member has an venting channel communicating with the vent hole; a second stop member disposed on the side of the first stop member away from the first wall, wherein along the direction from the first stop member to the second stop member, the projected area of ​​the second stop member on the valve cover is smaller than the projected area of ​​the first stop member on the valve cover; and an elastic seal member disposed between the first stop member and the second stop member and covering one end of the venting channel, wherein the elastic seal member abuts against the inner circumferential surface of the valve cover, wherein the elastic seal member is configured to elastically deform when the gas pressure in the battery cell reaches the first preset threshold, and the venting portion is used to connect the venting channel to the outside of the valve cover when the edge of the elastic seal member elastically deforms.

[0010] In the above technical solution, the first and second stop members serve to clamp and fix the elastic seal, enabling the elastic seal to maintain contact with the inner circumferential surface of the valve cover to achieve a stable sealing effect. Furthermore, in the direction from the first to the second stop member, since the projected area of ​​the second stop member on the valve cover is smaller than that of the first stop member, it provides deformation space for the elastic seal to undergo elastic deformation. Thus, when the gas pressure inside the casing reaches a first preset threshold, the outer circumferential area of ​​the elastic seal will locally deform towards the second stop member under the pressure of the gas, thereby forming a gap between the elastic seal and the valve cover for gas passage. The gas passes sequentially through the vent hole, the vent channel, and the gap between the elastic seal and the valve cover, and is finally discharged to the outside from the vent on the valve cover, thereby relieving pressure and reducing the risk of battery cells bulging, deforming, or even rupturing.

[0011] In some embodiments of this application, the exhaust portion includes a connecting groove, the valve cover includes a top wall and a side wall surrounding the periphery of the top wall, the connecting groove and the valve cover are disposed on the side wall and located between the top wall and the elastic seal, or the connecting groove is disposed on the top wall and located between the second stop member and the side wall.

[0012] In the above technical solution, the connecting groove can be disposed on the side wall of the valve cover or on the top wall of the valve cover. When the connecting groove is disposed on the side wall of the valve cover, it is specifically located in the area between the surface of the elastic seal opposite to the vent hole and the top wall of the valve cover. When the connecting groove is disposed on the top wall of the valve cover, it is specifically located between the outer peripheral surface of the second stop member and the side wall of the valve cover. In this way, when the elastic seal undergoes elastic deformation, gas can pass through the vent channel and then through the gap formed between the elastic seal and the side wall, and finally be discharged from the outside of the valve cover through the connecting groove, thereby achieving the purpose of pressure relief.

[0013] In some embodiments of this application, the exhaust assembly further includes a positioning post disposed on the top wall and extending toward the first wall, wherein the second stop member is provided with a positioning hole, and the positioning post passes through the positioning hole and abuts against the elastic seal.

[0014] In the above technical solution, the positioning post and the side of the elastic seal opposite to the exhaust hole abut against each other, so that when the elastic seal undergoes elastic deformation, the contact point between the elastic seal and the positioning post provides a stopping force toward the elastic seal, thereby facilitating the elastic deformation of the circumferential edge of the elastic seal when the gas pressure in the housing reaches a first preset threshold, so as to form a gap between the elastic seal and the side wall of the valve cover for gas passage.

[0015] In some embodiments of this application, the positioning post coincides with the central axis of the resilient seal.

[0016] In the above technical solution, the positioning post coincides with the central axis of the elastic seal, which facilitates the synchronous elastic deformation of the circumferential edge of the elastic seal, thereby helping the gas to be discharged quickly.

[0017] In some embodiments of this application, the projection of the vent hole onto the vent passage is located within the vent passage along the direction from the first wall to the first stop member.

[0018] In the above technical solution, the cross-sectional area of ​​the exhaust channel is larger than that of the exhaust hole along the axis perpendicular to the exhaust hole. When the gas pressure inside the housing reaches the first preset threshold, the elastic seal undergoes elastic deformation and forms a gap with the valve cover. The gas can quickly enter the exhaust channel through the exhaust hole and pass through the gap formed between the elastic seal and the valve cover, and finally be discharged from the exhaust part on the valve cover.

[0019] In some embodiments of this application, the second stop member includes a silicone member or a rubber member.

[0020] In the above technical solution, when the elastic seal undergoes elastic deformation, the circumferential edge of the second stopper generates a certain stress due to contact and stop with the elastic seal. By setting the second stopper as a silicone or rubber component, which has a certain degree of flexibility, the instantaneous stress on the elastic seal can be improved when the elastic seal undergoes elastic deformation, thereby reducing the risk of the elastic seal breaking due to stress concentration and helping to improve the reliability of the elastic seal.

[0021] In some embodiments of this application, the battery cell further includes a pressure relief mechanism disposed on the first wall. The pressure relief mechanism is configured to be actuated to release internal pressure when the pressure inside the battery cell reaches a second preset threshold, wherein the second preset threshold is greater than the first preset threshold.

[0022] In the above technical solution, it is understood that the pressure relief mechanism can be actuated when thermal runaway occurs within the battery cell due to temperature or pressure reaching a second preset threshold, thereby releasing substances within the battery cell and achieving pressure relief protection, thus helping to further improve the safety of the battery cell. Specifically, if the first preset threshold is less than the second preset threshold, meaning that the gas pressure generated inside the battery cell due to the chemical reaction between the dehydrating agent and water is insufficient to cause thermal runaway, and the first preset threshold is reached, the gas can only be discharged from the venting assembly and not from the pressure relief mechanism, thus helping to improve the reliability and stability of the battery cell.

[0023] In some embodiments of this application, the outer casing includes a housing and a top cover, the housing having an opening and the top cover sealing the opening, wherein the top cover is configured as the first wall.

[0024] In the above technical solution, the top cover serves as the first wall, i.e., the top cover is provided with an exhaust hole. The exhaust assembly is located on the side of the top cover away from the shell, so that when gas is generated inside the shell, the gas rises along the inside of the shell to the location of the top cover and is discharged from the exhaust assembly provided on the top cover, which helps to improve exhaust efficiency.

[0025] In some embodiments of this application, the exhaust device includes a one-way exhaust valve.

[0026] In the above technical solution, the exhaust device is a one-way exhaust valve, which allows gas to be discharged from the inside of the battery cell to the outside, but not from the outside into the battery cell.

[0027] In some embodiments of this application, the dehydrating agent includes one or more of the following types:

[0028] Nitrogenides of any one or more of the alkali metals, alkaline earth metals, and aluminum;

[0029] Phosphates of any one or more of the alkali metals, alkaline earth metals, and aluminum.

[0030] In the above technical solutions, the dehydrating agent in this application includes one or more of the types listed above. These dehydrating agents readily react with water. To better demonstrate the dehydration mechanism of the dehydrating agent, this application selects to replace alkali metals and / or alkaline earth metals and / or aluminum elements with the chemical symbol M, and the chemical formula of the nitride is M. x N y The chemical formula of the phosphide is M x P y The following are some types of dehydrating agents that readily react with water, and their chemical equations are as follows:

[0031] M x N y +H₂O→M(OH) y +NH3↑;

[0032] M x P y +H₂O→M(OH) y +PH3↑.

[0033] Therefore, the dehydrating agent provided in this application can absorb water in the positive electrode active material and undergo a chemical reaction when mixed with the positive electrode active material to reduce the moisture in the battery cell, thereby protecting the solid electrolyte interface inside the battery cell and improving the cycle life of the battery cell. In addition, the solid components obtained from the reaction are distributed around the positive electrode active material, and the generated gas can be discharged from the exhaust component, thereby reducing the risk of expansion and deformation inside the battery cell due to gas generation, and thus improving the reliability of the battery cell.

[0034] Secondly, this application provides a battery device comprising a battery cell as described in any one of the embodiments of the first aspect.

[0035] The battery device provided in this application includes any of the battery cells described in the first aspect embodiment, and therefore also has the technical effects of any of the above embodiments, which will not be repeated here.

[0036] Thirdly, this application provides an electrical device including a battery device as described in the second aspect embodiment, the battery device being used to supply power to the electrical device.

[0037] The electrical device provided in this application includes the battery device described in the second aspect embodiment, and therefore also has the technical effects of any of the above embodiments, which will not be repeated here. Attached Figure Description

[0038] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0039] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0040] Figure 2 This is an exploded view of the battery device provided in some embodiments of this application;

[0041] Figure 3 This is an exploded structural diagram of a battery cell provided in some embodiments of this application;

[0042] Figure 4 A cross-sectional view of a battery cell provided in some embodiments of this application;

[0043] Figure 5 for Figure 4 A partial structural diagram of a battery cell is shown.

[0044] Figure 6 A cross-sectional view of the top cover and exhaust device assembled according to some embodiments of this application;

[0045] Figure 7 This is a schematic diagram of the valve cover structure provided in some embodiments of this application;

[0046] Figure 8 A schematic diagram of the assembly structure of the first stop member and the elastic seal member provided in some embodiments of this application;

[0047] Figure 9 This is a schematic diagram of the structure of the second stopper provided in some embodiments of this application.

[0048] The attached figures are labeled as follows:

[0049] 1000, vehicles;

[0050] 100. Battery assembly; 200. Controller; 300. Motor;

[0051] 10. Housing; 11. First housing; 12. Second housing; 20. Battery cell; 21. Top cover; 21a. Electrode terminal; 211. Vent; 22. Housing; 23. Electrode assembly; 23a. Tab; 24. Vent channel; 25. Vent assembly; 251. Valve cover; 252. First stop; 2521. Positioning hole; 253. Second stop; 254. Elastic seal; 255. Positioning post. Detailed Implementation

[0052] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0054] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0055] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0056] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0057] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0058] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0059] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0060] Currently, judging from market trends, the application of battery devices is becoming increasingly widespread. Battery devices are not only used in energy storage power systems such as hydropower, thermal power, wind power, and solar power plants, but also widely applied in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of battery device applications, market demand is also constantly increasing.

[0061] A battery device typically has one or more battery cells. The operating environment of the battery can affect the lifespan of the battery cells. For example, in a high-temperature environment, the electrochemical reaction rate within the battery cell will increase, leading to a decrease in capacity. Furthermore, the electrolyte within the battery cell will decompose and undergo side reactions, resulting in a shortened battery cycle life.

[0062] To address the problem of electrolyte decomposition and side reactions within battery cells leading to shortened cell lifespan, this application designs a battery cell that incorporates a dehydrating agent into the positive electrode active material. This agent absorbs water from the positive electrode active material and reacts chemically with the water to generate gas. Simultaneously, a vent is provided on the top cover of the battery cell, with a corresponding venting assembly on its outer side. This venting assembly is activated to release gas when the internal gas pressure reaches a first preset threshold. This achieves both reduced internal water content and timely gas removal, lowering the risk of electrode assembly volume expansion and improving the battery cell's stability and lifespan.

[0063] The battery device disclosed in this application can be used, but is not limited to, in electrical devices such as vehicles, ships, or aircraft. A power system for this electrical device can be composed of battery cells and batteries disclosed in this application. This helps reduce the risk of battery cell expansion, deformation, or damage, and improves the stability of the battery device.

[0064] This application provides an electrical device that uses a battery as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0065] For ease of explanation, the following embodiments will be described using a vehicle 1000 as an example of an electrical device according to an embodiment of this application.

[0066] Please refer to Figure 1 , Figure 1This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 100 is provided inside the vehicle 1000, and the battery device 100 can be located at the bottom, front, or rear 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 the 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 supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during starting, navigation, and driving.

[0067] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0068] See Figure 2 , Figure 2 This is an exploded structural diagram of a battery device provided in some embodiments of this application. The battery device 100 mentioned in the embodiments of this application may include one or more battery cell assemblies 20 for providing voltage and capacity. A battery cell assembly 20 may include multiple battery cells 20, which are connected in series, parallel, or mixed connections via busbars.

[0069] In some embodiments, the battery cell assembly is typically formed by arranging multiple battery cells 20.

[0070] As an example, the battery cell 20 assembly can be a battery module, which is formed by arranging and fixing multiple battery cells 20 together to form an independent module. As an example, a battery module can be formed by bundling multiple battery cells 20 together with cable ties.

[0071] In some embodiments, the battery device 100 may be a battery pack, which includes a housing and one or more battery cell 20 assemblies housed within the housing.

[0072] As an example, the battery cell 20 assembly can be housed in a housing by fixing the battery module in the housing.

[0073] As an example, the battery cell 20 assembly can also be housed in the housing by directly fixing multiple battery cells 20 to the housing.

[0074] As an example, the housing 10 may include a first housing 11 and a second housing 12. The first housing 11 and the second housing 12 are fastened together to form a closed space inside the housing 10 to house the battery cell 20 assembly. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first housing 11 may be an end cap or a bottom plate.

[0075] As an example, the housing 10 may include an end cap, a frame, and a base plate. The end cap and the base plate are respectively connected to the frame, so that the interior of the housing forms an enclosed space to house the battery cells 20 assembly.

[0076] In some embodiments, the housing 10 may be part of the chassis structure of the vehicle 1000. 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.

[0077] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use battery cells 20, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles and spacecraft.

[0078] Please see Figures 3 to 5 , Figure 3 This is an exploded structural diagram of a battery cell provided in some embodiments of this application; Figure 4 A cross-sectional view of a battery cell provided in some embodiments of this application; Figure 5 for Figure 4 The diagram shows a partial structural schematic of a battery cell. This application provides a battery cell 20, including a casing, an electrode assembly 23, and a venting assembly 25. The casing has a receiving cavity; the electrode assembly 23 is housed within the receiving cavity and includes a positive electrode sheet. The positive electrode sheet includes a positive current collector and a positive electrode film layer disposed on the surface of the positive current collector. The positive electrode film layer includes a positive electrode active material and a dehydrating agent. The dehydrating agent can chemically react with water in the positive electrode active material to generate gas. The casing has a first wall with a vent hole 211. The venting assembly 25 is disposed on the first wall and covers the vent hole 211. The venting assembly 25 is configured to be actuated to release internal gas when the gas pressure inside the battery cell 20 reaches a first preset threshold.

[0079] In this embodiment of the application, the battery cell 20 can be a secondary battery, which refers to a battery cell 20 that can be used again after being discharged by recharging to activate the active materials.

[0080] The battery cell 20 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.

[0081] A battery cell 20 typically includes an electrode assembly 23. The electrode assembly 23 includes a positive electrode, a negative electrode, and a separator, with the separator positioned between the negative and positive electrode. During the charging and discharging process of the battery cell 20, active ions (e.g., lithium ions) repeatedly insert and extract between the positive and negative electrode. The separator, positioned between the positive and negative electrodes, prevents short circuits between them while allowing active ions to pass through.

[0082] In some embodiments, the positive electrode sheet may include a positive current collector and a positive active material disposed on at least one surface of the positive current collector.

[0083] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0084] As an example, the positive current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, titanium, or silver. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0085] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium manganese iron phosphate, and lithium manganese iron phosphate and carbon composites. Examples of lithium transition metal oxides may include, but are not limited to, lithium cobalt oxides (such as LiCoO2), lithium nickel oxides (such as LiNiO2), lithium manganese oxides (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxides, lithium manganese cobalt oxides, lithium nickel manganese oxides, lithium nickel cobalt manganese oxides (such as LiNi1 / 3Co1 / 3Mn1 / 3O2 (also abbreviated as NCM333), LiNi0.5Co0.2Mn0.3O2 (also abbreviated as NCM523), LiNi0.5Co The following are included: 0.25Mn0.25O2 (also known as NCM211), LiNi0.6Co0.2Mn0.2O2 (also known as NCM622), LiNi0.8Co0.1Mn0.1O2 (also known as NCM811), lithium nickel cobalt aluminum oxides (such as LiNi0.8Co0.15Al0.05O2), and their modified compounds. Modified compounds refer to substances obtained by doping or coating, etc., based on the above-mentioned materials.

[0086] In some embodiments, the dehydrating agent includes one or more of the following:

[0087] Nitrogenides of any one or more of the alkali metals, alkaline earth metals, and aluminum;

[0088] Phosphates of any one or more of the alkali metals, alkaline earth metals, and aluminum.

[0089] The dewatering agent in this application includes one or more of the types listed above. These dewatering agents readily react with water. To better illustrate the dewatering mechanism of the dewatering agent, this application replaces alkali metals and / or alkaline earth metals and / or aluminum elements with the chemical symbol M. The chemical formula for nitrides is MxNy, and the chemical formula for phosphides is MxPy. The listed types of dewatering agents readily react with water, and the reaction chemical equations are as follows:

[0090] MxNy + H2O → M(OH)y + NH3↑;

[0091] MxPy + H2O → M(OH)y + PH3↑.

[0092] In addition, dehydrating agents may also include the following types:

[0093] Oxides of any one or more of the alkali metals, alkaline earth metals, and aluminum;

[0094] Peroxides of any one or more of the following elements: alkali metals, alkaline earth metals, and aluminum.

[0095] One or more hydrides of alkali metals, alkaline earth metals, and aluminum.

[0096] The chemical formulas for the oxides are MxOy, the peroxides are MxO2, and the hydrides are MHy. The chemical equations for their reactions with water are as follows:

[0097] MxOy + H2O → M(OH)y;

[0098] MxO2 + H2O → M(OH)y + O2↑;

[0099] MHy + H2O → M(OH)y + H2↑;

[0100] Therefore, the dehydrating agent provided in this application can absorb water in the positive electrode active material and undergo a chemical reaction when mixed with the positive electrode active material to reduce the moisture in the battery cell 20, thereby protecting the solid electrolyte interface inside the battery cell 20 and improving the cycle life of the battery cell 20. In addition, the solid components obtained from the reaction are distributed around the positive electrode active material, and the generated gas can be discharged from the exhaust component 25, thereby reducing the risk of expansion and deformation inside the battery cell 20 due to gas generation, and thus improving the reliability of the battery cell 20.

[0101] Understandably, the dehydrating agent in this application can not only absorb and react with the moisture in the positive electrode active material, but also react with the moisture in the electrolyte, thus helping to reduce the moisture content in the battery cell 20.

[0102] In these embodiments, this application selects to premix the positive electrode active material with the dehydrating agent to form a mixed material. Based on the strong water absorption properties of the dehydrating agent, the water absorption reaction of the dehydrating agent will occur during the premixing process of the mixed material to reduce the water content in the positive electrode active material.

[0103] In some embodiments, the positive electrode may be made of foamed metal. The foamed metal may be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. When foamed metal is used as the positive electrode, the surface of the foamed metal may or may not contain a positive electrode active material. As an example, positive electrode active material may be filled and / or deposited within the foamed metal.

[0104] In some embodiments, electrode assembly 23 further includes a negative electrode sheet, which may include a negative current collector.

[0105] As an example, the negative electrode current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, titanium, or silver. The composite current collector may include a polymer material substrate and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0106] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0107] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0108] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cell 20. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as negative electrode active materials for battery cell 20 may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0109] In some embodiments, the negative electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. When foamed metal is used as the negative electrode sheet, the surface of the foamed metal may or may not have a negative electrode active material.

[0110] As an example, negative electrode active materials can be filled or / and deposited within the negative electrode current collector.

[0111] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0112] In some embodiments, electrode assembly 23 further includes an isolator disposed between the positive and negative electrodes.

[0113] In some embodiments, the separator is a separator membrane. This application does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0114] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator can be a single component located between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes. An inorganic particle coating, an organic particle coating, or an organic / inorganic composite coating can also be applied to the surface of the separator.

[0115] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0116] The electrode assembly 23 can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked.

[0117] In some embodiments, the electrode assembly 23 is a wound structure. The positive electrode and the negative electrode are wound into a wound structure.

[0118] In some embodiments, the electrode assembly 23 has a stacked structure.

[0119] As an example, multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.

[0120] As an example, multiple positive electrode plates can be provided, and negative electrode plates can be folded to form multiple stacked folded segments, with a positive electrode plate sandwiched between adjacent folded segments.

[0121] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0122] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0123] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0124] In some embodiments, the electrode assembly 23 may be cylindrical, flat, or polygonal in shape.

[0125] In some embodiments, the electrode assembly 23 is provided with tabs 23a, which can conduct current from the electrode assembly 23. The tabs 23a include a positive tab 23a and a negative tab 23a.

[0126] In some embodiments, the outer casing can be a steel casing, an aluminum casing, a plastic casing (such as a polypropylene casing), a composite metal casing (such as a copper-aluminum composite casing), or an aluminum-plastic film, etc. In some embodiments, the outer casing can be a sealed structure or a non-sealed structure. As an example, when the outer casing is a non-sealed structure, the outer casing serves to protect the electrode assembly 23, and a sealing bag is also included between the outer casing and the electrode assembly 23. The sealing bag is used to encapsulate the electrode assembly 23 and the electrolyte. Specifically, the sealing bag can be a bag-shaped insulating component or an aluminum-plastic film. When the outer casing is a sealed structure, it is used to encapsulate the electrode assembly 23 and the electrolyte, etc.

[0127] As an example, the battery cell 20 can be a cylindrical battery cell 20, a prismatic battery cell 20, a pouch battery cell 20, or a battery cell 20 of other shapes. The prismatic battery cell 20 includes a square battery cell 20, a blade-shaped battery cell 20, and a multi-prismatic battery, such as a hexagonal prismatic battery. There are no particular limitations in this application.

[0128] In some embodiments, the exhaust assembly 25 is a one-way exhaust valve.

[0129] According to the battery cell 20 provided in this application, by adding a dehydrating agent to the positive electrode active material of the positive electrode film layer, the dehydrating agent can chemically react with the water in the positive electrode active material, thereby reducing the water in the electrolyte and reducing the hydrofluoric acid generated by the chemical reaction of lithium salt in the electrolyte, thus protecting the solid electrolyte interface inside the battery cell 20 and improving the cycle life of the battery cell 20. Since the dehydrating agent produces gas, such as ammonia, when it chemically reacts with water in the positive electrode active material, this application further provides an exhaust port 211 on the first wall of the casing and an exhaust assembly 25 on the outer side of the first wall. The exhaust assembly 25 can be actuated when the gas pressure inside the battery cell 20 reaches a first preset threshold to discharge the gas inside the battery cell 20 to the outside, thereby reducing the risk of deformation or even rupture caused by gas generation inside the electrode cell due to volume expansion, and thus improving the reliability of the battery cell 20.

[0130] Please see Figures 6 to 9 , Figure 6 A cross-sectional view of the top cover and exhaust device assembled according to some embodiments of this application; Figure 7 This is a schematic diagram of the valve cover structure provided in some embodiments of this application; Figure 8 A schematic diagram of the assembly structure of the first stop member and the elastic seal member provided in some embodiments of this application; Figure 9This is a schematic diagram of the structure of the second stop member provided in some embodiments of this application. According to some embodiments of this application, the exhaust assembly 25 includes a valve cover 251, a first stop member 252, a second stop member 253, and an elastic sealing member 254. The valve cover 251 is located on the side of the first wall away from the electrode assembly 23 and covers the exhaust port 211, and the valve cover 251 has at least one exhaust portion; the first stop member 252 is fitted against the inner circumferential surface of the valve cover 251 and connected to the first wall, and the first stop member 252 has an exhaust channel 24 communicating with the exhaust port 211; the second stop member 253 is located on the side of the first stop member 252 away from the first wall, and along the direction from the first stop member 252 to the second stop member 253, the projected area of ​​the second stop member 253 on the valve cover 251 is smaller than... The first stop member 252 is projected onto the valve cover 251; the elastic seal member 254 is disposed between the first stop member 252 and the second stop member 253 and covers one end of the exhaust passage 24, and the elastic seal member 254 abuts against the inner circumferential surface of the valve cover 251. The elastic seal member 254 is configured to undergo elastic deformation when the gas pressure in the battery cell 20 reaches a first preset threshold. The exhaust part is used to connect the exhaust passage 24 to the outside of the valve cover 251 when the edge of the elastic seal member 254 undergoes elastic deformation.

[0131] For example, the first stop member 252 is a plate-shaped structure, which can be a circular plate or a rectangular plate. The second stop member 253 is an annular structure, and an annular exhaust channel 24 is formed in the middle of the second stop member 253.

[0132] For example, the resilient seal 254 can be a resilient gasket, such as a metal or alloy resilient gasket, and the resilient seal 254 is capable of elastic deformation when subjected to force and returning to its initial shape when the force is removed.

[0133] The first stopper 252 and the second stopper 253 clamp and fix the elastic seal 254, ensuring that the elastic seal 254 maintains contact with the inner circumferential surface of the valve cover 251 to achieve a stable sealing effect. Furthermore, in the direction from the first stopper 252 to the second stopper 253, since the projected area of ​​the second stopper 253 on the valve cover 251 is smaller than that of the first stopper 252, it provides deformation space for the elastic seal 254 to undergo elastic deformation. Thus, when the gas pressure inside the housing reaches... When the first preset threshold is reached, the outer periphery of the elastic seal 254 will undergo local elastic deformation towards the second stop 253 under the pressure of the gas. This allows a gap to be formed between the elastic seal 254 and the valve cover 251 for gas to pass through. The gas passes through the exhaust port 211, the exhaust channel 24 and the gap between the elastic seal 254 and the valve cover 251 in sequence, and is finally discharged to the outside from the exhaust part on the valve cover 251. This can relieve pressure and reduce the risk of the battery cell 20 bulging, deforming or even rupturing.

[0134] Please see Figure 7 According to some embodiments of this application, the exhaust section includes a connecting groove 2511, the valve cover 251 includes a top wall and a side wall surrounding the periphery of the top wall, the connecting groove 2511 is disposed on the side wall of the valve cover 251 and is located between the top wall and the elastic seal 254, or the connecting groove 2511 is disposed on the top wall and is located between the second stop member 253 and the side wall.

[0135] The connecting groove 2511 extends through the valve cover 251 to enable communication with the exhaust passage 24.

[0136] The connecting groove 2511 can be disposed on either the side wall or the top wall of the valve cover 251. When the connecting groove is disposed on the side wall of the valve cover 251, it is specifically located in the area between the surface of the elastic seal 254 facing away from the exhaust port 211 and the top wall of the valve cover 251. When the connecting groove is disposed on the top wall of the valve cover 251, it is specifically located between the outer peripheral surface of the second stop 253 and the side wall of the valve cover 251. In this way, when the elastic seal 254 undergoes elastic deformation, gas can pass through the exhaust channel 24 and then through the gap formed between the elastic seal 254 and the side wall, and finally be discharged from the outside of the valve cover 251 through the connecting groove to achieve the purpose of pressure relief.

[0137] In some embodiments, the exhaust portion may also be an exhaust port 211, an exhaust channel, etc.

[0138] Please see Figure 7According to some embodiments of this application, the exhaust assembly 25 further includes a positioning post 255, which is disposed on the top wall and extends toward the first wall. The second stop member 253 is provided with a positioning hole 2521, through which the positioning post 255 passes and abuts against the elastic seal member 254.

[0139] For example, the positioning post 255 can be welded to the top wall, bonded to it, or integrally formed.

[0140] The positioning post 255 serves to position and install the first stop member 252. The positioning post 255 abuts against the side of the elastic seal 254 opposite to the exhaust port 211, so that when the elastic seal 254 undergoes elastic deformation, the contact point between the elastic seal 254 and the positioning post 255 provides a stopping force towards the elastic seal 254. This facilitates the elastic deformation of the circumferential edge of the elastic seal 254 when the gas pressure inside the housing reaches a first preset threshold, forming a gap between it and the side wall of the valve cover 251 for gas passage.

[0141] According to some embodiments of this application, the positioning post 255 coincides with the central axis of the resilient seal 254.

[0142] The positioning post 255 coincides with the central axis of the elastic seal 254, which facilitates the synchronous elastic deformation of the circumferential edge of the elastic seal 254, thereby helping the gas to be discharged quickly.

[0143] According to some embodiments of this application, along the direction from the first wall to the first stop member 252, the projection of the exhaust hole 211 on the exhaust channel 24 is located within the exhaust channel 24.

[0144] That is, in the direction perpendicular to the axis of the exhaust port 211, the cross-sectional area of ​​the exhaust channel 24 is larger than the cross-sectional area of ​​the exhaust port 211. When the gas pressure inside the housing reaches the first preset threshold, the elastic seal 254 undergoes elastic deformation and forms a gap with the valve cover 251. The gas can quickly enter the exhaust channel 24 through the exhaust port 211 and pass through the gap formed between the elastic seal 254 and the valve cover 251, and finally be discharged from the exhaust part on the valve cover 251.

[0145] According to some embodiments of this application, the second stop member 253 includes a silicone member or a rubber member.

[0146] When the elastic seal 254 undergoes elastic deformation, the circumferential edge of the second stop 253 generates a certain stress due to contact and stop with the elastic seal 254. By setting the second stop 253 as a silicone or rubber component, which has a certain degree of flexibility, the instantaneous stress on the elastic seal 254 can be improved when the elastic seal 254 undergoes elastic deformation, thereby reducing the risk of the elastic seal 254 breaking due to stress concentration and helping to improve the reliability of the elastic seal 254.

[0147] According to some embodiments of this application, the battery cell 20 further includes a pressure relief mechanism disposed on the first wall. The pressure relief mechanism is configured to be actuated to release internal pressure when the pressure inside the battery cell 20 reaches a second preset threshold, wherein the second preset threshold is greater than the first preset threshold.

[0148] The pressure relief mechanism is used to release the internal gas of the battery cell 20.

[0149] For example, the first preset threshold is set in the range of 0.14MPa to 0.18MPa, such as 0.15MPa or 0.16MPa.

[0150] As an example, when the internal pressure or temperature of the battery cell 20 reaches a second preset threshold, the pressure relief mechanism is activated to release the internal pressure or temperature. When the internal pressure or temperature of the battery cell 20 reaches the second preset threshold, the pressure relief mechanism performs its action or a weak structure in the pressure relief mechanism is destroyed, thereby forming an opening or channel for the internal pressure or temperature to be released. The design of this second preset threshold varies depending on the design requirements. The second preset threshold may depend on the materials of one or more of the positive electrode, negative electrode, electrolyte, and separator in the battery cell 20. For example, the second preset threshold may be set in the range of 0.5 MPa to 1 MPa.

[0151] As an example, the pressure relief mechanism can be integrally molded with the housing.

[0152] As an example, the pressure relief mechanism can also be separately installed and connected to the housing.

[0153] The term "actuation" as used in this application refers to the pressure relief mechanism being activated or undergoing a certain state, thereby releasing the internal pressure and temperature of the battery cell 20. The actions of the pressure relief mechanism may include, but are not limited to: movement of components within the pressure relief mechanism to form an exhaust channel 24, rupture, breakage, tearing, or opening of at least a portion of the pressure relief mechanism, etc. When the pressure relief mechanism is actuated, the high-temperature, high-pressure substances inside the battery cell 20 are discharged outwards from the actuated portion as waste. This method allows for pressure and temperature relief of the battery cell 20 under controllable pressure or temperature conditions, thereby preventing potentially more serious accidents.

[0154] In some embodiments, when the housing is a non-sealed structure, the pressure relief mechanism can be configured as a through hole for venting gas inside the battery cell 20.

[0155] The emissions from the battery cell 20 mentioned in this application include, but are not limited to: electrolyte, dissolved or split positive and negative electrode plates, fragments of separators, high-temperature and high-pressure gases generated by the reaction, flames, etc.

[0156] Understandably, the pressure relief mechanism can be activated when thermal runaway occurs within the battery cell 20 due to temperature or pressure reaching a second preset threshold, thereby releasing substances within the battery cell 20 and achieving pressure relief protection, thus helping to further improve the safety of the battery cell 20 in use. Specifically, if the first preset threshold is less than the second preset threshold, meaning that the gas pressure generated inside the battery cell 20 due to the chemical reaction between the dehydrating agent and water is insufficient to cause thermal runaway, and the first preset threshold is reached, the gas can only be discharged from the exhaust assembly 25 and not from the pressure relief mechanism, thus helping to improve the reliability and stability of the battery cell 20 in use.

[0157] According to some embodiments of this application, the outer casing includes a housing 22 and a top cover 21, the housing 22 having an opening, and the top cover 21 sealing the opening, wherein the top cover 21 is configured as a first wall.

[0158] For example, the housing 22 may have one or more openings. The top cover 21 may also have one or more openings.

[0159] In this embodiment, the top cover 21 can serve as the first wall, that is, the top cover 21 is provided with an exhaust hole 211, and the exhaust assembly 25 is located on the side of the top cover 21 away from the housing 22. This facilitates the gas to rise along the inside of the housing 22 to the location of the top cover 21 when gas is generated inside the housing 22, and to be discharged from the exhaust assembly 25 provided on the top cover 21, which helps to improve exhaust efficiency.

[0160] According to some embodiments of this application, a one-way permeable membrane is provided on the side of the vent 211 opposite to the vent assembly 25. The one-way permeable membrane is configured to allow gas to be discharged unidirectionally from the vent 211. This further reduces the risk of external gas entering the battery cell 20.

[0161] According to some embodiments of this application, see Figures 1 to 3This application provides a battery cell 20, including a casing, an electrode assembly 23, and a venting assembly 25. The casing includes a housing 22 and a top cover 21. The housing 22 has an opening and defines a receiving cavity. The electrode assembly 23 is housed within the receiving cavity, and the top cover 21 seals the opening. The electrode assembly 23 includes a positive electrode sheet, which includes a positive current collector and a coating layer applied to the surface of the positive current collector. The coating layer includes a positive active material and a dehydrating agent. The dehydrating agent reacts with water in the positive active material to generate gas. The venting assembly 25 is located on the side of the top cover 21 opposite to the housing 22. The top cover 21 has a vent hole 211, and the venting assembly 25 seals the vent hole 211. The venting assembly 25 is actuated to release internal gas when the gas pressure inside the battery cell 20 reaches a first preset threshold. By adopting the above technical solution, the risk of deformation or damage due to volume expansion caused by internal gas generation in the battery cell 20 can be reduced, which is beneficial to improving the stability of the battery cell 20 in use.

[0162] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A battery cell, characterized in that, include: The outer shell has a receiving cavity; An electrode assembly is housed within the receiving cavity. The electrode assembly includes a positive electrode sheet, which includes a positive current collector and a positive electrode film layer disposed on the surface of the positive current collector. The positive electrode film layer includes a positive electrode active material and a dehydrating agent. The dehydrating agent is capable of chemically reacting with water in the positive electrode active material to generate gas. The exhaust assembly has a first wall on the housing, the first wall having an exhaust hole, the exhaust assembly being disposed on the first wall and covering the exhaust hole, and the exhaust assembly being configured to be actuated to release internal gas when the gas pressure inside the battery cell reaches a first preset threshold.

2. The battery cell according to claim 1, characterized in that, The exhaust assembly includes: A valve cover is disposed on the side of the first wall opposite to the electrode assembly and covers the vent hole, and the valve cover is provided with at least one venting part; The first stop member is fitted to the inner circumferential surface of the valve cover and connected to the first wall, and the first stop member is provided with an exhaust channel connected to the exhaust hole. The second stop is provided on the side of the first stop away from the first wall. Along the direction from the first stop to the second stop, the projected area of ​​the second stop on the valve cover is smaller than the projected area of ​​the first stop on the valve cover. An elastic seal is disposed between the first stop member and the second stop member, and covers one end of the exhaust passage, and the elastic seal abuts against the inner circumferential surface of the valve cover. The elastic seal is configured to elastically deform when the gas pressure inside the battery cell reaches the first preset threshold, and the exhaust portion is used to connect the exhaust channel to the outside of the valve cover when the edge of the elastic seal elastically deforms.

3. The battery cell according to claim 2, characterized in that, The exhaust section includes a connecting groove, and the valve cover includes a top wall and a side wall surrounding the periphery of the top wall. The connecting groove is disposed on the side wall and located between the top wall and the elastic seal, or the connecting groove is disposed on the top wall and located between the second stop member and the side wall.

4. The battery cell according to claim 3, characterized in that, The exhaust assembly also includes a positioning post disposed on the top wall and extending toward the first wall. The second stop member is provided with a positioning hole, and the positioning pin passes through the positioning hole and abuts against the elastic seal.

5. The battery cell according to claim 4, characterized in that, The positioning post coincides with the central axis of the elastic seal.

6. The battery cell according to any one of claims 2-5, characterized in that, Along the direction from the first wall to the first stop member, the projection of the vent hole on the vent channel is located within the vent channel.

7. The battery cell according to any one of claims 1-5, characterized in that, The second stopper includes a silicone part or a rubber part.

8. The battery cell according to any one of claims 1-5, characterized in that, The battery cell also includes a pressure relief mechanism disposed on the first wall. The pressure relief mechanism is configured to be actuated to release internal pressure when the pressure inside the battery cell reaches a second preset threshold. Wherein, the second preset threshold is greater than the first preset threshold.

9. The battery cell according to any one of claims 1-5, characterized in that, The outer casing includes a housing and a top cover, the housing having an opening, and the top cover sealing the opening. The top cover is configured as the first wall.

10. The battery cell according to any one of claims 1-5, characterized in that, The exhaust device includes a one-way exhaust valve.

11. The battery cell according to any one of claims 1-5, characterized in that, The dehydrating agent includes one or more of the following types: Nitrogenides of any one or more of the alkali metals, alkaline earth metals, and aluminum; Phosphates of any one or more of the alkali metals, alkaline earth metals, and aluminum.

12. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1-11.

13. An electrical appliance, characterized in that, Includes the battery device as described in claim 12, wherein the battery device is used to supply power to the electrical device.

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