Battery cells, battery packs, energy storage devices, energy storage systems, and charging networks

Abstract

This application provides a battery cell, a battery device, an energy storage device, an energy storage system, and a charging network, belonging to the field of battery device technology. The battery cell includes a housing, a first wall with a pressure relief hole; a pressure relief mechanism installed in the pressure relief hole; an electrode assembly disposed within the housing; an electrolyte disposed within the housing; and a baffle movably disposed on the inner side of the first wall, capable of covering at least a portion of the pressure relief hole when the pressure relief mechanism is actuated. The baffle has an exhaust channel; when the baffle covers the pressure relief hole, the exhaust channel connects the pressure relief hole to the interior of the housing, reducing electrolyte leakage and thus improving the reliability of the battery device.

Description

Technical Field

[0001] This application relates to the field of battery device technology, specifically to a battery cell, battery device, energy storage device, energy storage system, and charging network. Background Technology

[0002] Energy conservation and emission reduction are key to the sustainable development of the automotive industry, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of this sustainable development. For electric vehicles, battery technology is a crucial factor in their development.

[0003] In battery device technology, the reliability of individual battery cells is a crucial issue. Therefore, improving the reliability of individual battery cells is a pressing technical problem that needs to be solved in battery device technology. Summary of the Invention

[0004] In view of the above problems, this application provides a battery cell, a battery device, an energy storage device, an energy storage system, and a charging network to reduce electrolyte leakage and thereby improve the reliability of the battery device.

[0005] In a first aspect, this application provides a battery cell, comprising: a housing, including a first wall, the first wall having a pressure relief hole; a pressure relief mechanism installed in the pressure relief hole; an electrode assembly disposed within the housing; an electrolyte disposed within the housing; and a baffle, the baffle being movably disposed on the inner side of the first wall, the baffle being capable of covering at least a portion of the pressure relief hole when the pressure relief mechanism is actuated;

[0006] The baffle is provided with an exhaust channel. When the baffle covers the pressure relief hole, the exhaust channel connects the pressure relief hole with the interior of the outer shell.

[0007] In the technical solution of this application embodiment, a movable baffle is provided on the inner side of the first wall. When the pressure relief mechanism is actuated, the baffle can continuously cover at least part of the pressure relief hole under the action of the internal and external pressure difference of the battery cell. This blocks the ejection of electrolyte from the casing, reduces the amount of electrolyte ejected with the airflow, lowers the possibility of electrolyte contacting external electronic components, and improves the reliability of the battery cell. Furthermore, since the baffle can still maintain communication between the pressure relief hole and the interior of the casing through the exhaust channel while covering at least part of the pressure relief hole, it can allow the airflow inside the casing to slowly discharge while blocking the ejection of electrolyte, thus reducing the internal air pressure of the battery cell.

[0008] In some embodiments, the orthographic projection of the baffle and the orthographic projection of the pressure relief mechanism at least partially overlap in the same projection plane perpendicular to the thickness direction of the first wall.

[0009] By making the orthographic projection of the baffle at least partially overlap with the orthographic projection of the pressure relief mechanism, at least a portion of the pressure relief mechanism can be shielded, and the ejection of electrolyte from the housing can be blocked.

[0010] In some embodiments, the battery cell further includes a first insulating member disposed between the first wall and the electrode assembly, the first insulating member having a through hole, and the baffle disposed between the first wall and the first insulating member and at least partially covering the through hole.

[0011] When the pressure relief mechanism is not activated, at least a portion of the baffle can cover the through hole, so that when the internal air pressure of the battery cell is too high, the baffle can approach and cover at least a portion of the pressure relief hole under the push of the airflow.

[0012] In some embodiments, a first groove is formed on the side of the first insulating member facing the first wall, the opening of the first groove is disposed toward the pressure relief mechanism, and the baffle is disposed in the first groove;

[0013] The through hole is located at the bottom of the first groove.

[0014] By forming a first groove on the side of the first insulating member facing the first wall and setting a through hole at the bottom of the first groove, and setting a baffle in the first groove, the first insulating member can provide installation space for the baffle while achieving insulation between the electrical connection components inside the housing and the end cover.

[0015] In some embodiments, a guide post is provided at the bottom of the first groove, and a guide hole is provided on the baffle. The baffle is slidably sleeved onto the guide post along the thickness direction of the first wall through the guide hole.

[0016] By cooperating with the guide post and the guide hole, the baffle can move closer to or further away from the pressure relief hole along the thickness direction of the first wall, thereby restricting the movement direction of the baffle.

[0017] In some embodiments, the softening point of the baffle is 70°C-150°C.

[0018] When the internal pressure of a battery cell increases, the pressure relief mechanism is activated. However, if the internal temperature of the battery cell does not reach 70°C, the baffle will cover at least part of the pressure relief hole, reducing the instantaneous venting rate of the battery cell. This reduces the possibility that the electrolyte inside the cell may be carried out by the airflow and affect external electronic components during the initial activation of the pressure relief mechanism. If the temperature of the battery cell continues to rise and thermal runaway occurs, when the internal temperature of the battery cell reaches 70°C-150°C, the baffle will soften and be discharged from the pressure relief hole, no longer blocking the electrolyte. A large amount of electrolyte will be discharged. At this time, since at least part of the airflow has been released along the venting channel, the probability of electrolyte ejection is reduced, allowing the electrolyte to be discharged under gravity.

[0019] In some embodiments, the softening point of the baffle is 80°C-120°C.

[0020] As the internal pressure of the battery cell increases, the internal temperature of the battery cell will gradually increase when the pressure relief mechanism is activated. By setting the softening point of the baffle to 80℃-120℃, the baffle can extend the blocking time of the electrolyte in the early stage of the pressure relief mechanism activation, and the temperature when a large amount of electrolyte is discharged can also be reduced.

[0021] In some embodiments, the baffle is made of polyethylene, polypropylene, or polyurethane.

[0022] The baffle is made of polyethylene, polypropylene, or polyurethane, which allows the baffle to soften.

[0023] In some embodiments, the thickness of the baffle is 0.5mm-5mm.

[0024] The thickness of the baffle should be set to 0.5mm-5mm. If the thickness of the baffle is too small, it is easy to deform under air pressure and it is difficult to effectively cover the pressure relief hole. If the thickness of the baffle is too large, it will be difficult to move due to the limited installation space.

[0025] In some embodiments, in the thickness direction of the first wall, the orthogonal projection of the baffle onto the first wall covers a portion of the pressure relief hole.

[0026] The baffle plate's orthogonal projection on the first wall covers part of the pressure relief hole, allowing the pressure relief hole to maintain communication with the interior of the housing through the area of ​​the pressure relief hole not covered by the baffle plate when the pressure relief mechanism is actuated.

[0027] In some embodiments, in the first direction, the maximum size of the baffle is greater than the maximum size of the pressure relief hole;

[0028] In the second direction, the maximum size of the baffle is smaller than the maximum size of the pressure relief hole;

[0029] The thickness direction of the first wall is perpendicular to both the first direction and the second direction.

[0030] Since the maximum size of the baffle in the first direction is greater than the maximum size of the pressure relief hole in the first direction, and the maximum size of the baffle in the second direction is smaller than the maximum size of the pressure relief hole in the second direction, the pressure relief hole can have an area not covered by the baffle in the second direction to maintain communication between the pressure relief hole and the interior of the housing.

[0031] In some embodiments, the exhaust channel includes an exhaust port that extends through the baffle along its thickness direction.

[0032] At this time, the exhaust channel is formed by the exhaust port, which will connect the pressure relief hole and the interior of the outer shell along the thickness direction of the baffle.

[0033] In some embodiments, in the same projection plane perpendicular to the thickness direction of the first wall, the orthographic projection area of ​​the vent is 0.5% to 15% of the orthographic projection area of ​​the pressure relief hole.

[0034] By setting the ratio of the projected area of ​​the vent hole to the projected area of ​​the pressure relief hole to 0.5% to 15%, the amount of electrolyte ejected with the airflow is reduced while venting. If the ratio is too small, it hinders gas discharge; if the ratio is too large, the likelihood of electrolyte ejection with the airflow increases, affecting the reliability of the battery cell.

[0035] In some embodiments, the baffle has a first surface facing the first wall; the exhaust passage includes an exhaust gap formed between the first surface and the inner surface of the first wall.

[0036] At this time, the exhaust channel is formed by the exhaust gap. By forming the exhaust gap between the first surface of the baffle and the inner surface of the first wall, the internal airflow of the battery cell can be slowly discharged through the exhaust gap and the pressure relief hole in sequence.

[0037] In some embodiments, the first surface is provided with protrusions.

[0038] When the first surface is provided with protrusions, the first surface will form a non-smooth surface. The part of the first surface with protrusions will abut against the inner surface of the first wall, and the part of the first surface without protrusions will form an exhaust gap with the inner surface of the first wall, so that the internal airflow of the battery cell can be slowly discharged.

[0039] In some embodiments, a plurality of protrusions are provided, each of the protrusions extending along a third direction, and the plurality of protrusions are spaced apart along a fourth direction;

[0040] The thickness direction of the baffle, the third direction, and the fourth direction are all perpendicular to each other.

[0041] At this time, an exhaust gap is formed between the two adjacent protrusions and the inner surface of the first wall, allowing the internal airflow of the battery cell to be slowly discharged.

[0042] In some embodiments, the housing includes a housing and an end cap, the housing having a receiving cavity and an opening communicating with the receiving cavity, the end cap being connected to the housing and closing the opening; the electrode assembly is disposed within the receiving cavity;

[0043] The first wall is disposed on the end cap.

[0044] The first wall is set on the end cover so that the pressure relief hole is set on the end cover, so that the internal airflow of the battery cell can be slowly discharged from the end cover side.

[0045] Secondly, this application provides a battery device that includes the battery cell described in the above embodiments.

[0046] The battery device provided according to this application includes the battery cell described in any one of the first aspect embodiments, and therefore has the technical effects described in any of the above embodiments, which will not be repeated here.

[0047] Thirdly, this application provides an energy storage device that includes the battery device described in the above embodiments.

[0048] The energy storage device provided in this application includes the battery device described in any one of the second aspect embodiments, and therefore has the technical effects described in any of the above embodiments, which will not be repeated here.

[0049] Fourthly, this application provides an energy storage system, which includes an energy storage converter and the energy storage device in the above embodiments, wherein the energy storage converter is used to electrically connect the power generation device and the energy storage device.

[0050] The energy storage system provided in this application includes the energy storage device described in any one of the third aspect embodiments, and therefore has the technical effects described in any of the above embodiments, which will not be repeated here.

[0051] Fifthly, this application provides a charging network including a charging pile and the energy storage device in the above embodiments, wherein the energy storage device is used to provide electrical energy to the charging pile.

[0052] The charging network provided in this application includes the energy storage device described in any one of the third aspect embodiments, and therefore has the technical effects described in any of the above embodiments, which will not be repeated here.

[0053] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the other objects, features and advantages of this application more obvious and understandable, specific embodiments of this application are given below. Attached Figure Description

[0054] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0055] Figure 1 This is a schematic diagram of the charging network structure in some embodiments of this application;

[0056] Figure 2 This is a schematic diagram of the energy storage system in some embodiments of this application;

[0057] Figure 3 This is a schematic diagram of the structure of the energy storage device in some embodiments of this application;

[0058] Figure 4 This is an exploded view of the battery device in some embodiments of this application;

[0059] Figure 5 This is a schematic diagram showing the exploded structure of a single battery cell in some embodiments of this application;

[0060] Figure 6 This is a schematic diagram of the structure of the battery device at the end cap in some embodiments of this application;

[0061] Figure 7 for Figure 6 A schematic diagram of the structure after removing the portion of the end cap with the first groove;

[0062] Figure 8 This is another structural schematic diagram of the battery device at the end cap of some embodiments of this application (the pressure relief mechanism is not actuated).

[0063] Figure 9 for Figure 8 Enlarged view of point A in the middle;

[0064] Figure 10 This is another structural schematic diagram of the battery device at the end cap of some embodiments of this application (the pressure relief mechanism is not actuated).

[0065] Figure 11 for Figure 10 Enlarged view of point B in the middle;

[0066] Figure 12 This is a schematic diagram of the structure of the baffle in some embodiments of this application;

[0067] Figure 13 This is another structural schematic diagram of the baffle according to some embodiments of this application;

[0068] Figure 14 This is another schematic diagram of the structure of the baffle in some embodiments of this application.

[0069] The reference numerals in the detailed embodiments are as follows:

[0070] 1000, Charging network; 2000, Energy storage system; 3000, Power generation device;

[0071] 100. Battery device;

[0072] 10. Box body; 11. First part; 12. Second part;

[0073] 20. Battery cell; 21. Casing; 210. First wall; 210a. Pressure relief hole; 211. End cap; 212. Housing; 22. Electrode assembly; 23. Terminal post; 24. Pressure relief mechanism; 25. Baffle; 251. Exhaust channel; 2511. Exhaust hole; 2512. Exhaust gap; 252. First surface; 2521. Protrusion; 26. First insulating element; 261. Through hole; 262. First groove;

[0074] 200. Energy storage device; 201. Energy storage container;

[0075] 300, charging piles;

[0076] 400. Energy storage converter;

[0077] Z, the thickness direction of the first wall; X, the first direction; Y, the second direction; M, the third direction; N, the fourth direction. Detailed Implementation

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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).

[0083] Currently, judging from market trends, the application of power battery devices is becoming increasingly widespread. Power 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 used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace, among other fields. With the continuous expansion of the application areas of power battery devices, the market demand is also constantly increasing.

[0084] The battery cells of the power battery device are generally sealed with explosion-proof plates (i.e., pressure relief mechanisms) in the pressure relief holes. During normal use of the battery cell, the explosion-proof plates can ensure the airtightness of the internal environment of the battery cell. When the internal air pressure of the battery cell is too high, the explosion-proof plates can be opened to release the pressure inside the battery cell.

[0085] However, when the explosion-proof diaphragm is opened to release pressure, the airflow caused by the huge pressure difference inside and outside the battery cell will carry the electrolyte out of the battery cell. During the application of the battery cell, a large amount of electrolyte will be sprayed out, which can cause insulation failure of external electronic components and reduce the reliability of the battery device.

[0086] To reduce electrolyte ejection when the explosion-proof plate is opened to release pressure, research has found that a blocking structure can be installed inside the pressure relief hole to block the electrolyte, thereby reducing electrolyte ejection and improving the reliability of the power battery device.

[0087] Based on the above considerations, in order to solve the problem of reduced reliability of the battery device due to electrolyte ejection during use, a battery cell is designed with a movable baffle on the inner side of the first wall. When the pressure relief mechanism is actuated, the baffle can cover at least part of the pressure relief hole and maintain communication between the pressure relief hole and the interior of the casing. This allows the baffle to block the ejection of electrolyte from the casing, reducing the amount of electrolyte ejected with the airflow, decreasing the possibility of electrolyte contacting external electronic components, and improving the reliability of the battery device.

[0088] The battery device disclosed in this application can be applied to energy storage devices such as energy storage containers or energy storage cabinets.

[0089] The battery device 100 will be described below with reference to the accompanying drawings.

[0090] Please refer to Figure 1 and Figure 3 , Figure 1 This is a schematic diagram of the structure of a charging network 1000 provided in some embodiments of this application. Figure 3 This is a schematic diagram of the structure of an energy storage device 200 provided in some embodiments of this application. Embodiments of this application provide a charging network 1000, which includes a charging pile 300 for charging electrical equipment. The charging network 1000 may also include an energy storage device 200, which is electrically connected to the charging pile 300 and provides power to the charging pile 300.

[0091] It should be noted that the charging pile 300 and the battery cells in the energy storage device 200 are electrically connected via cables, and the battery cells can supply their stored electrical energy to the charging pile 300. The charging pile 300 has a connector that can be connected to electrical equipment, thereby replenishing the equipment's power. The application of the energy storage device 200 in this charging network 1000 can effectively improve the safety of the charging network 1000 and also help to enhance the flexibility of the charging network 1000 during deployment.

[0092] In a charging network 1000, there can be one charging pile 300, and the energy storage device 200 provides power to the one charging pile 300; there can also be multiple charging piles 300, and the energy storage device 200 provides power to multiple charging piles 300.

[0093] As an example, such as Figure 1 As shown, the charging network 1000 includes an energy storage device 200 and two charging piles 300, with the energy storage device 200 providing power to the two charging piles 300.

[0094] The energy storage device 200 may include a battery device 100, which is electrically connected to the charging pile 300 so that the battery device 100 can provide power to the charging pile 300.

[0095] Please refer to Figure 2 and Figure 3 , Figure 2 This is a schematic diagram of the structure of an energy storage system 2000 provided in some embodiments of this application. Embodiments of this application provide an energy storage system 2000. The energy storage system 2000 includes an energy storage converter 400, which is electrically connected to a generator 3000 to convert the electrical power provided by the generator 3000. The energy storage system 2000 may also include an energy storage device 200, which is electrically connected to the energy storage converter 400. The energy storage converter 400 converts the electrical energy provided by the generator 3000 and stores it in the energy storage device 200.

[0096] A power conversion device is used to connect the power generation device 3000 and the energy storage device 200. The power generation device 3000 generates electrical energy and stores it in the energy storage device 200 via the power conversion device. The use of the energy storage device 200 in the energy storage system 2000 effectively improves its operational safety. In specific implementations, the power generation equipment can be solar panels, hydroelectric power generation equipment, thermal power generation equipment, etc. This application does not limit the specific type of power generation equipment.

[0097] As an example, such as Figure 2 As shown, the energy storage system 2000 includes an energy storage device 200 and an energy storage converter 400. The two power generation devices 3000 respectively transmit the generated electrical energy to the energy storage converter 400, and the energy storage converter 400 introduces the electrical energy into the energy storage device 200 for storage.

[0098] Please refer to Figure 3 The energy storage device 200 includes an energy storage box 201, and a battery device 100 is installed inside the energy storage box 201.

[0099] As an example, the energy storage device 200 can be an energy storage container, an energy storage cabinet, etc.

[0100] As an example, energy storage device 200 can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems. Energy storage power stations can store electrical energy during off-peak hours and provide power to relevant users or electrical equipment during peak hours. Wind power generation systems collect wind energy from wind turbines, convert it into electrical energy, and store it in energy storage device 200. Solar power generation systems can convert solar energy into electrical energy, store it in energy storage device 200, and supply it to users as needed. Mobile power systems can supply power to relevant electrical equipment in areas where the mains power supply cannot reach, such as remote mountainous areas and remote wilderness areas. Temporary power supply systems can provide power to users when there is insufficient power supply.

[0101] Please refer to Figure 4 , Figure 4 This is an exploded structural diagram of a battery device 100 provided in some embodiments of this application. The battery device 100 includes a housing 10 and battery cells 20, with the battery cells 20 housed within the housing 10. The housing 10 provides space for the battery cells 20, and the housing 10 can employ various structures.

[0102] In some embodiments, the housing 10 may include a first portion 11 and a second portion 12, which overlap each other, and together define a receiving space for accommodating the battery cell 20. The second portion 12 may be a hollow structure with one open end, and the first portion 11 may be a plate-like structure, with the first portion 11 covering the open side of the second portion 12 so that the first portion 11 and the second portion 12 together define the receiving space; alternatively, the first portion 11 and the second portion 12 may both be hollow structures with one open side, with the open side of the first portion 11 covering the open side of the second portion 12. Of course, the housing 10 formed by the first portion 11 and the second portion 12 can be of various shapes, such as a cylinder, a cuboid, etc.

[0103] In the battery device 100, there can be multiple battery cells 20, which can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 20 are connected in both series and parallel configurations. Multiple battery cells 20 can be directly connected in series, parallel, or in a mixed manner, and then the entire assembly of the multiple battery cells 20 is housed within the housing 10. Alternatively, the battery device 100 can also consist of multiple battery cells 20 first connected in series, parallel, or in a mixed manner to form battery device modules, and then these modules are connected in series, parallel, or in a mixed manner to form a whole, which is then housed within the housing 10. The battery device 100 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 20.

[0104] Each battery cell 20 can be a secondary battery device, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0105] Please refer to Figure 5 , Figure 5 This is an exploded structural diagram of a battery cell 20 provided in some embodiments of this application. The battery cell 20 refers to the smallest unit constituting the battery device 100. For example... Figure 5 The battery cell 20 includes a casing 21, an electrode assembly 22, and other functional components.

[0106] The outer casing 21 includes an end cap 211 and a housing 212. The end cap 211 is a component that covers the opening of the housing 212 to isolate the internal environment of the battery cell 20 from the external environment. The shape of the end cap 211 can be adapted to the shape of the housing 212 to fit it. Optionally, the end cap 211 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 211 is less prone to deformation under pressure and impact, allowing the battery cell 20 to have higher structural strength and improved safety performance. Functional components such as terminals 23 can be provided on the end cap 211. The terminals 23 can be used to electrically connect to the electrode assembly 22 for outputting or inputting electrical energy into the battery cell 20. In some embodiments, the end cap 211 can also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold. The end cap 211 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose any special limitations on this. In some embodiments, an insulating element (such as the first insulating element 26) can be provided on the inner side of the end cap 211 to isolate the electrical connection components inside the housing 212 from the end cap 211, thereby reducing the risk of short circuit. For example, the insulating element can be plastic, rubber, etc.

[0107] The housing 212 is a component used to cooperate with the end cap 211 to form the internal environment of the battery cell 20. This internal environment can accommodate the electrode assembly 22, electrolyte, and other components. The housing 212 and the end cap 211 can be independent components. An opening can be provided on the housing 212, and the end cap 211 can be used to close the opening to form the internal environment of the battery cell 20. Alternatively, the end cap 211 and the housing 212 can be integrated. Specifically, the end cap 211 and the housing 212 can form a common connecting surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 212, the end cap 211 closes the housing 212. The housing 212 can be of various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 212 can be determined according to the specific shape and size of the electrode assembly 22. The material of the housing 212 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. This application embodiment does not impose any special limitations on this.

[0108] Electrode assembly 22 is the component in the battery cell 20 where electrochemical reactions occur. The housing 212 may contain one or more electrode assemblies 22. The electrode assembly 22 is mainly formed by winding or stacking positive and negative electrode sheets, and typically a separator is provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active material constitute the main body of the electrode assembly 22, while the portions of the positive and negative electrode sheets without active material each constitute a tab. The positive and negative tabs may be located together at one end of the main body or separately at both ends of the main body. During the charging and discharging process of the battery device 100, the positive and negative active materials react with the electrolyte, and the tabs connect to the electrode terminals to form a current loop.

[0109] According to some embodiments of this application, refer to Figure 5 Please refer to further details. Figures 6 to 14 , Figure 6 This is a schematic diagram of the battery device at the end cap in some embodiments of this application. Figure 7 for Figure 4 A schematic diagram of the structure after removing the portion of the end cap with the first groove. Figure 8 This is another structural schematic diagram of the battery device at the end cap of some embodiments of this application (the pressure relief mechanism is not actuated). Figure 9 for Figure 7 Enlarged diagram of point A in the middle. Figure 10 This is another structural schematic diagram of the battery device at the end cap of some embodiments of this application (the pressure relief mechanism is not actuated). Figure 11 for Figure 10 Enlarged diagram at point B in the middle. Figure 12 This is a schematic diagram of the structure of the baffle in some embodiments of this application. Figure 13This is another structural schematic diagram of the baffle according to some embodiments of this application. Figure 14 This is another schematic diagram of the structure of the baffle in some embodiments of this application.

[0110] This application provides a battery cell 20, including a housing 21, an electrode assembly 22, a pressure relief mechanism 24, and an electrolyte. The housing 21 includes a first wall 210, and the first wall 210 is provided with a pressure relief hole 210a. The pressure relief mechanism 24 is installed in the pressure relief hole 210a. The electrode assembly 22 is disposed inside the housing 21, and the electrolyte is disposed inside the housing 21.

[0111] The battery cell 20 also includes a baffle 25, which is movably disposed inside the first wall 210. The baffle 25 can cover at least part of the pressure relief hole 210a when the pressure relief mechanism 24 is actuated, and maintain the communication between the pressure relief hole 210a and the interior of the outer casing 21. Specifically, the baffle 25 is provided with an exhaust channel 251. When the baffle 25 covers the pressure relief hole 210a, the exhaust channel 251 connects the pressure relief hole 210a and the interior of the outer casing 21.

[0112] In the technical solution of this application embodiment, a movable baffle 25 is provided on the inner side of the first wall 210. When the pressure relief mechanism 24 is actuated, the baffle 25 can continuously cover at least part of the pressure relief hole 210a under the action of the internal and external pressure difference of the battery cell 20. This blocks the ejection of electrolyte from the casing 21, reduces the amount of electrolyte ejected with the airflow, and reduces the possibility of electrolyte contacting external electronic components. This, in turn, reduces the possibility of insulation failure of external electronic components caused by electrolyte leakage, and improves the reliability of the battery cell 20. In addition, since the baffle 25 can still maintain the communication between the pressure relief hole 210a and the interior of the casing 21 through the exhaust channel 251 while covering at least part of the pressure relief hole 210a, the airflow inside the casing 21 can still be slowly discharged while blocking the ejection of electrolyte, thereby reducing the internal air pressure of the battery cell 20. When the supporting force of the internal air pressure of the battery cell 20 is less than the weight of the baffle 25, the baffle 25 will fall back to its initial position. When the baffle 25 is in its initial position, it will be far away from the pressure relief hole 210a.

[0113] According to some embodiments of this application, refer to Figure 7 In the same projection plane perpendicular to the thickness direction Z of the first wall 210, the orthographic projection of the baffle 25 and the orthographic projection of the pressure relief mechanism 24 at least partially overlap.

[0114] For example, the thickness direction Z of the first wall 210 is parallel to the height direction of the battery cell 20.

[0115] By making the orthographic projection of the baffle 25 at least partially overlap with the orthographic projection of the pressure relief mechanism 24, at least part of the pressure relief mechanism 24 can be shielded, and the ejection of electrolyte inside the housing 21 can be blocked, reducing the amount of electrolyte ejected with the airflow, reducing the possibility of electrolyte contacting external electronic components, and improving the reliability of the battery cell 20.

[0116] According to some embodiments of this application, refer to Figures 6-11 The battery cell 20 also includes a first insulating member 26, which is disposed between the first wall 210 and the electrode assembly 22. The first insulating member 26 has a through hole 261, and a baffle 25 is disposed between the first wall 210 and the first insulating member 26 and at least partially covers the through hole 261.

[0117] "The baffle 25 is disposed between the first wall 210 and the first insulating member 26 and at least partially covers the through hole 261" means that the baffle 25 is disposed between the first wall 210 and the first insulating member 26, and the entire baffle 25 covers the through hole 261; or, the baffle 25 is disposed between the first wall 210 and the first insulating member 26, and a portion of the baffle 25 covers the through hole 261.

[0118] When the pressure relief mechanism 24 is not activated, at least a portion of the baffle 25 can cover the through hole 261, so that when the internal air pressure of the battery cell 20 is too high, the baffle 25 can approach and cover at least a portion of the pressure relief hole 210a under the push of the airflow, so as to block the spraying of electrolyte in the casing 21 by the baffle 25, reduce the amount of electrolyte sprayed out with the airflow, reduce the possibility of electrolyte contacting external electronic components, and improve the reliability of the battery cell 20.

[0119] According to some embodiments of this application, refer to Figures 8-11 The first insulating member 26 has a first groove 262 formed on the side facing the first wall 210. The opening of the first groove 262 is set towards the pressure relief mechanism 24, and the baffle 25 is set in the first groove 262.

[0120] The through hole 261 is provided at the bottom of the first groove 262.

[0121] By forming a first groove 262 on the side of the first insulating member 26 facing the first wall 210, and setting a through hole 261 at the bottom of the first groove 262, and setting a baffle 25 in the first groove 262, the first insulating member 26 can provide installation space for the baffle 25 while achieving insulation between the electrical connection components in the housing 21 and the end cover 211.

[0122] According to some embodiments of this application, a guide post may be provided at the bottom of the first groove 262, and a guide hole is provided on the baffle 25. The baffle 25 is slidably sleeved on the guide post along the thickness direction Z of the first wall 210 through the guide hole.

[0123] By cooperating with the guide post and the guide hole, the baffle 25 can move closer to or further away from the pressure relief hole 210a along the thickness direction Z of the first wall 210, thereby restricting the movement direction of the baffle 25.

[0124] According to some embodiments of this application, refer to Figures 6-10 The softening point of the baffle 25 is 70℃-150℃.

[0125] For example, the softening point of the baffle 25 is 75°C, 83°C, 85°C, 90°C, 95°C, 98°C, 103°C, 112°C, 118°C, 124°C, 133°C, 142°C or 146°C.

[0126] "The softening point of baffle 25" refers to the temperature at which baffle 25 begins to soften and lose its solid properties during heating. A higher softening point results in better resistance to deformation and cracking, but poorer plasticity and flexibility. A lower softening point results in better plasticity and flexibility, but poorer resistance to deformation and cracking.

[0127] When the internal pressure of the battery cell 20 increases, the pressure relief mechanism 24 is activated. However, if the internal temperature of the battery cell 20 does not reach 70°C, the baffle 25 will cover at least part of the pressure relief hole 210a, reducing the instantaneous exhaust rate of the battery cell 20. This reduces the possibility that the electrolyte inside the battery cell 20 may be carried out by the airflow and affect external electronic components during the initial activation of the pressure relief mechanism 24. If the temperature of the battery cell 20 continues to rise and thermal runaway occurs, when the internal temperature of the battery cell 20 reaches 70°C-150°C, the baffle 25 will soften and be discharged through the pressure relief hole 210a, no longer blocking the electrolyte. A large amount of electrolyte will be discharged. At this time, since at least part of the airflow has been discharged and released along the exhaust channel 251, the probability of electrolyte ejection can be reduced, allowing the electrolyte to be discharged under gravity.

[0128] According to some embodiments of this application, the softening point of the baffle 25 can be 80°C-120°C.

[0129] As the internal air pressure of the battery cell 20 increases, the internal temperature of the battery cell 20 will gradually increase when the pressure relief mechanism 24 is activated. By setting the softening point of the baffle 25 to 80℃-120℃, the baffle 25 can extend the blocking time of the electrolyte in the early stage of the pressure relief mechanism 24 activation, and the temperature when a large amount of electrolyte is discharged can also be reduced.

[0130] According to some embodiments of this application, the baffle 25 is made of polyethylene (PE), polypropylene (PP), or polyurethane.

[0131] The material of the baffle 25 is selected as polyethylene, polypropylene or polyurethane, so that the baffle 25 can soften.

[0132] According to some embodiments of this application, the thickness of the baffle 25 is 0.5mm-5mm.

[0133] For example, the thickness of the baffle 25 is 0.8mm, 1.2mm, 1.4mm, 1.8mm, 2.3mm, 3.0mm, 3.6mm, 4.2mm or 4.7mm.

[0134] Since the thickness of the first insulating component 26 in the battery cell 20 is generally 5.5mm-6mm, in order to enable the movable baffle 25, the thickness of the baffle 25 is set to 0.5mm-5mm. If the thickness of the baffle 25 is too small, it is easy to deform under air pressure (not deformation due to heat softening) and it is difficult to effectively cover the pressure relief hole 210a. If the thickness of the baffle 25 is too large, it will be difficult to move due to the limited installation space.

[0135] According to some embodiments of this application, refer to Figure 7 and Figure 12 In the thickness direction Z of the first wall 210, the orthogonal projection of the baffle 25 on the first wall 210 covers the portion of the pressure relief hole 210a.

[0136] For example, the surface of the baffle 25 facing the first wall 210 can be a smooth surface, and / or the surface of the first wall 210 facing the baffle 25 can be a smooth surface.

[0137] For example, the baffle 25 is a sheet-like structure. The cross-section of the baffle 25 perpendicular to the thickness direction Z of the first wall 210 is rectangular, elliptical, or circular, etc.

[0138] For example, the area of ​​the cross section of the baffle 25 perpendicular to the thickness direction Z of the first wall 210 is greater than the area of ​​the cross section of the pressure relief mechanism 24 perpendicular to the thickness direction Z of the first wall 210.

[0139] The baffle 25 is positioned so that its orthogonal projection on the first wall 210 covers part of the pressure relief hole 210a. When the pressure relief mechanism 24 is actuated, the pressure relief hole 210a is kept connected to the interior of the outer casing 21 through the area of ​​the pressure relief hole 210a not covered by the baffle 25, so that the airflow inside the outer casing 21 can still be slowly discharged, thereby reducing the internal air pressure of the battery cell 20.

[0140] According to some embodiments of this application, refer to Figure 7 and Figure 12 In the first direction X, the maximum size of the baffle 25 is greater than the maximum size of the pressure relief hole 210a.

[0141] In the second direction Y, the maximum size of the baffle 25 is smaller than the maximum size of the pressure relief hole 210a.

[0142] The thickness direction Z of the first wall 210, the first direction X, and the second direction Y are perpendicular to each other.

[0143] For example, the first direction X is parallel to the length direction of the battery cell 20, and the second direction Y is parallel to the width direction of the battery cell 20. In other embodiments, the first direction may intersect the length direction of the battery cell, and the second direction may intersect the width direction of the battery cell.

[0144] Since the maximum size of the baffle 25 in the first direction X is greater than the maximum size of the pressure relief hole 210a in the first direction X, and the maximum size of the baffle 25 in the second direction Y is smaller than the maximum size of the pressure relief hole 210a in the second direction Y, there can be an area of ​​the pressure relief hole 210a that is not covered by the baffle 25 in the second direction Y, so as to maintain the communication between the pressure relief hole 210a and the interior of the housing 21, allowing the airflow inside the housing 21 to be slowly discharged, thereby reducing the internal air pressure of the battery cell 20.

[0145] In other embodiments not shown in the figure, the first direction may be perpendicular to the thickness direction of the first wall, and the second direction may be perpendicular to the thickness direction of the first wall, with the first direction intersecting but not perpendicular to the second direction, as long as there is an area of ​​the pressure relief hole that is not covered by the baffle.

[0146] According to some embodiments of this application, refer to Figure 13 The exhaust passage 251 includes an exhaust hole 2511, which penetrates the baffle 25 along the thickness direction of the baffle 25.

[0147] At this time, the exhaust channel 251 is composed of an exhaust hole 2511. The exhaust hole 2511 connects the pressure relief hole 210a and the interior of the outer casing 21 along the thickness direction of the baffle 25, so that the internal airflow of the battery cell 20 can be slowly discharged through the exhaust hole 2511 and the pressure relief hole 210a, thereby reducing the internal air pressure of the battery cell 20.

[0148] According to some embodiments of this application, refer to Figure 13 In the same projection plane perpendicular to the thickness direction Z of the first wall 210, the orthographic projection area of ​​the vent 2511 is 0.5% to 15% of the orthographic projection area of ​​the pressure relief hole 210a. Preferably, the orthographic projection area of ​​the vent 2511 is 2% to 10% of the orthographic projection area of ​​the pressure relief hole 210a.

[0149] For example, the projected area of ​​the vent 2511 is 1%, 3%, 5%, 6%, 8%, 11%, 12.5%, or 14% of the projected area of ​​the pressure relief vent 210a.

[0150] For example, refer to Figure 13 The vent 2511 can be composed of a single hole, in which case the projected area of ​​the single hole is 0.5% to 15% of the projected area of ​​the pressure relief hole 210a.

[0151] In other embodiments not shown in the figure, the vent hole may also be composed of a plurality of small holes arranged at intervals. In this case, the sum of the orthographic projection areas of each small hole is 0.5% to 15% of the orthographic projection area of ​​the pressure relief hole.

[0152] By setting the ratio of the projected area of ​​the vent 2511 to the projected area of ​​the pressure relief hole 210a to 0.5% to 15%, the amount of electrolyte ejected with the airflow is reduced while venting. If the ratio is too small, it hinders gas discharge. If the ratio is too large, the likelihood of electrolyte ejection with the airflow increases, affecting the reliability of the battery cell 20.

[0153] According to some embodiments of this application, refer to Figure 14 The baffle 25 has a first surface 252 facing the first wall 210. The exhaust passage 251 includes an exhaust gap 2512 formed between the first surface 252 and the inner surface of the first wall 210.

[0154] For example, the inner surface of the first wall 210 is the surface of the first wall 210 facing the baffle 25.

[0155] At this time, the exhaust channel 251 is formed by the exhaust gap 2512. By forming the exhaust gap 2512 between the first surface 252 of the baffle 25 and the inner surface of the first wall 210, the internal airflow of the battery cell 20 can be slowly discharged through the exhaust gap 2512 and the pressure relief hole 210a in sequence, thereby reducing the internal air pressure of the battery cell 20.

[0156] According to some embodiments of this application, refer to Figure 14 The first surface 252 is provided with a protrusion 2521.

[0157] For example, the cross-sectional shape of the protrusion 2521 includes, but is not limited to, triangles, quadrilaterals, or semicircles.

[0158] When the first surface 252 is provided with a protrusion 2521, the first surface 252 will form a non-smooth surface. The position of the first surface 252 with the protrusion 2521 will abut against the inner surface of the first wall 210. The position of the first surface 252 without the protrusion 2521 will form an exhaust gap 2512 with the inner surface of the first wall 210, so that the internal airflow of the battery cell 20 can be slowly discharged through the exhaust gap 2512 and the pressure relief hole 210a, thereby reducing the internal air pressure of the battery cell 20.

[0159] According to some embodiments of this application, refer to Figure 14 Multiple protrusions 2521 are provided, each protrusion 2521 extends along the third direction M, and the multiple protrusions 2521 are spaced apart along the fourth direction N.

[0160] The thickness direction, third direction M, and fourth direction N of the baffle 25 are perpendicular to each other.

[0161] At this time, an exhaust gap 2512 is formed between the two adjacent protrusions 2521 and the inner surface of the first wall 210, so that the internal airflow of the battery cell 20 can be slowly discharged, reducing the internal air pressure of the battery cell 20.

[0162] In other embodiments not shown in the figures, the first surface may also be a rough surface consisting of irregular raised or recessed fine stripes or particles.

[0163] In other embodiments not shown in the figure, the exhaust channel may also include both an exhaust hole and an exhaust gap. The exhaust hole penetrates the baffle along the thickness direction of the baffle, and the exhaust gap is formed between the first surface and the inner surface of the first wall. In this case, since both the exhaust hole and the exhaust gap can realize the discharge of gas, the ratio of the positive projection area of ​​the exhaust hole to the positive projection area of ​​the pressure relief hole in the same projection plane in the thickness direction of the first wall can be a smaller range of 0.5% to 15%, such as 0.5% to 8%.

[0164] In other embodiments not shown in the figures, the baffle may cover a portion of the pressure relief hole in the orthographic projection of the first wall along the thickness direction of the first wall, and an exhaust channel may be provided on the baffle. For example, in the thickness direction of the first wall, the baffle covers a portion of the pressure relief hole in the orthographic projection of the first wall, and an exhaust hole is provided on the baffle. In this case, within the same projection plane along the thickness direction of the first wall, the ratio of the sum of the orthographic projection area of ​​the area of ​​the pressure relief hole not covered by the baffle and the orthographic projection area of ​​the exhaust hole to the orthographic projection area of ​​the pressure relief hole is 0.5% to 15%.

[0165] According to some embodiments of this application, refer to Figure 5The outer casing 21 includes a housing 212 and an end cap 211. The housing 212 has a receiving cavity and an opening communicating with the receiving cavity. The end cap 211 is connected to the housing 212 and closes the opening. The electrode assembly 22 is disposed within the receiving cavity.

[0166] The first wall 210 is provided on the end cap 211.

[0167] The first wall 210 is disposed on the end cover 211 so that the pressure relief hole 210a is disposed on the end cover 211, so that the internal airflow of the battery cell 20 can be slowly discharged from the end cover 211 side.

[0168] In other embodiments not shown in the figures, to enable the installation and mobility of the baffle, a sliding hole communicating with the pressure relief hole can also be provided in the first wall. The sliding hole is located inside the pressure relief hole. The first wall has an inner surface facing the electrode assembly and an outer surface facing away from the electrode assembly. The pressure relief hole protrudes from the outer surface of the first wall, and the sliding hole protrudes from the inner surface of the first wall. The diameter of the pressure relief hole is smaller than the diameter of the sliding hole. The baffle is movably disposed within the sliding hole along the thickness direction of the first wall.

[0169] For example, "the sliding hole is located inside the pressure relief hole" means that the sliding hole is located on the side of the pressure relief hole closer to the electrode assembly.

[0170] By moving the baffle plate within the sliding hole along the thickness direction of the first wall, the baffle plate can continuously cover at least part of the pressure relief hole under the action of the internal and external pressure difference of the battery cell. The baffle plate blocks the spraying of electrolyte from the casing, reduces the amount of electrolyte sprayed out with the airflow, reduces the possibility of electrolyte contacting external electronic components, and improves the reliability of the battery cell.

[0171] It should be noted that if a sliding hole is provided in the first wall and the baffle is movably installed in the sliding hole along the thickness direction of the first wall, the thickness of the first wall must be relatively thick. For example, the thickness of the first wall should be greater than the sum of the thickness of the pressure relief mechanism and the thickness of the baffle, so as to realize the installation of the pressure relief mechanism and enable the baffle to move along the thickness direction of the first wall.

[0172] According to some embodiments of this application, this application also provides a battery device 100, including a battery cell 20 of any of the above schemes.

[0173] According to some embodiments of this application, this application also provides an electrical device including a battery device 100 of any of the above schemes, and the battery device 100 is used to provide electrical energy to the electrical device.

[0174] The electrical equipment can be any of the aforementioned devices or systems that utilize battery devices 100.

[0175] According to some embodiments of this application, see Figure 4 , Figures 6 to 11This application provides a battery device 100, whose housing 10 includes a plurality of battery cells 20, which are arranged in multiple rows and columns.

[0176] The battery cell 20 includes a housing 21, an electrode assembly 22, a pressure relief mechanism 24, a baffle 25, a first insulating element 26, and an electrolyte. The housing 21 includes a shell 212 and an end cap 211. The shell 212 has a receiving cavity and an opening communicating with the receiving cavity. The end cap 211 is connected to the shell 212 and closes the opening. The electrode assembly 22 is disposed in the receiving cavity.

[0177] The end cap 211 is provided with a first wall 210, the first wall 210 is provided with a pressure relief hole 210a, the pressure relief mechanism 24 is installed in the pressure relief hole 210a, the electrode assembly 22 is disposed inside the outer shell 21, and the electrolyte is disposed inside the outer shell 21.

[0178] The first insulating member 26 is disposed between the first wall 210 and the electrode assembly 22. A first groove 262 is formed on the side of the first insulating member 26 facing the first wall 210. The groove opening of the first groove 262 is disposed facing the pressure relief mechanism 24. A through hole 261 is provided at the bottom of the groove of the first groove 262.

[0179] The baffle 25 is movably disposed in the first groove 262 along the thickness direction Z of the first wall 210 and is located between the first wall 210 and the first insulating member 26.

[0180] In the thickness direction Z of the first wall 210, the orthogonal projection of the baffle 25 on the first wall 210 covers part of the pressure relief hole 210a.

[0181] The softening point of the baffle 25 is 100℃, and the material of the baffle 25 is polyethylene.

[0182] The baffle 25 is a sheet-like structure, and its cross-section perpendicular to the thickness direction Z of the first wall 210 is rectangular. In the first direction X, the maximum size of the baffle 25 is larger than the maximum size of the pressure relief hole 210a, and in the second direction Y, the maximum size of the baffle 25 is smaller than the maximum size of the pressure relief hole 210a, so that there is an area in the pressure relief hole 210a that is not covered by the baffle 25 in the second direction Y.

[0183] The thickness of the baffle 25 is 2mm.

[0184] When the pressure relief mechanism 24 is not activated, at least a portion of the baffle 25 can cover the through hole 261.

[0185] When the internal pressure of the battery cell 20 becomes too high, the pressure relief mechanism 24 is activated. However, if the internal temperature of the battery cell 20 does not reach 70°C, the baffle 25 can continuously cover part of the pressure relief hole 210a under the action of the internal and external pressure difference of the battery cell 20. This reduces the amount of electrolyte ejected with the airflow, lowers the possibility of electrolyte contacting external electronic components, and improves the reliability of the battery cell 20. At the same time, the area of ​​the pressure relief hole 210a not covered by the baffle 25 will maintain the communication between the pressure relief hole 210a and the interior of the outer casing 21, allowing the airflow inside the outer casing 21 to slowly escape and reduce the internal pressure of the battery cell 20.

[0186] When the supporting force of the internal air pressure of the battery cell 20 is less than the weight of the baffle 25, the baffle 25 will fall back to its initial position. When the baffle 25 is in its initial position, it will be far away from the pressure relief hole 210a.

[0187] If the temperature of the battery cell 20 continues to rise and thermal runaway occurs, when the internal temperature of the battery cell 20 reaches 100°C, the baffle 25 will soften due to heat and be discharged through the pressure relief hole 210a, no longer blocking the electrolyte, and a large amount of electrolyte will be discharged.

[0188] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, include: The outer casing includes a first wall, the first wall being provided with a pressure relief hole; A pressure relief mechanism is installed at the pressure relief hole; Electrode assembly, disposed within the housing; Electrolyte is disposed inside the outer casing; as well as A baffle plate is movably disposed on the inner side of the first wall, and the baffle plate can cover at least part of the pressure relief hole when the pressure relief mechanism is actuated; The baffle is provided with an exhaust channel. When the baffle covers the pressure relief hole, the exhaust channel connects the pressure relief hole with the interior of the outer shell. The softening point of the baffle is 70℃-150℃.

2. The battery cell according to claim 1, characterized in that, In the same projection plane perpendicular to the thickness direction of the first wall, the orthographic projection of the baffle at least partially overlaps with the orthographic projection of the pressure relief mechanism.

3. The battery cell according to claim 2, characterized in that, The battery cell further includes a first insulating member, which is disposed between the first wall and the electrode assembly. The first insulating member has a through hole, and the baffle is disposed between the first wall and the first insulating member and at least partially covers the through hole.

4. The battery cell according to claim 3, characterized in that, The first insulating member has a first groove formed on the side facing the first wall, the opening of the first groove is disposed facing the pressure relief mechanism, and the baffle is disposed in the first groove; The through hole is located at the bottom of the first groove.

5. The battery cell according to claim 4, characterized in that, The bottom of the first groove is provided with a guide post, and the baffle is provided with a guide hole. The baffle is slidably sleeved onto the guide post along the thickness direction of the first wall through the guide hole.

6. The battery cell according to claim 1, characterized in that, The softening point of the baffle is 80℃-120℃.

7. The battery cell according to any one of claims 1-5, characterized in that, The baffle is made of polyethylene, polypropylene, or polyurethane.

8. The battery cell according to any one of claims 1-5, characterized in that, The thickness of the baffle is 0.5mm-5mm.

9. The battery cell according to any one of claims 1-5, characterized in that, In the thickness direction of the first wall, the orthogonal projection of the baffle on the first wall partially covers the pressure relief hole.

10. The battery cell according to claim 9, characterized in that, In the first direction, the maximum size of the baffle is greater than the maximum size of the pressure relief hole; In the second direction, the maximum size of the baffle is smaller than the maximum size of the pressure relief hole; The thickness direction of the first wall is perpendicular to both the first direction and the second direction.

11. The battery cell according to claim 10, characterized in that, The exhaust channel includes an exhaust hole that penetrates the baffle along the thickness direction of the baffle.

12. The battery cell according to claim 11, characterized in that, In the same projection plane perpendicular to the thickness direction of the first wall, the orthographic projection area of ​​the vent hole is 0.5% to 15% of the orthographic projection area of ​​the pressure relief hole.

13. The battery cell according to claim 10, characterized in that, The baffle has a first surface facing the first wall; the exhaust passage includes an exhaust gap formed between the first surface and the inner surface of the first wall.

14. The battery cell according to claim 13, characterized in that, The first surface is provided with protrusions.

15. The battery cell according to claim 14, characterized in that, The protrusions are provided in multiple ways, each of the protrusions extends along a third direction, and the multiple protrusions are spaced apart along a fourth direction; The thickness direction of the baffle, the third direction, and the fourth direction are all perpendicular to each other.

16. The battery cell according to claim 1, characterized in that, The housing includes a shell and an end cap. The shell has a receiving cavity and an opening communicating with the receiving cavity. The end cap is connected to the shell and closes the opening. The electrode assembly is disposed within the receiving cavity. The first wall is disposed on the end cap.

17. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1-16.

18. An energy storage device, characterized in that, Includes the battery device as described in claim 17.

19. An energy storage system, characterized in that, It includes an energy storage converter and an energy storage device as described in claim 18, wherein the energy storage converter is used to electrically connect the power generation device and the energy storage device.

20. A charging network, characterized in that, It includes a charging pile and an energy storage device as described in claim 18, the energy storage device being used to provide electrical energy to the charging pile.

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