Battery cell, battery device and electrical equipment

Abstract

The present application discloses a battery cell, a battery device and an electrical equipment, relating to the technical field of batteries. Wherein, the battery cell includes a housing and a ventilation structure. The housing forms a receiving cavity and a ventilation channel communicating with the receiving cavity. The ventilation channel includes an air inlet and an air outlet. The ventilation structure includes a switching member disposed in the ventilation channel. At least a part of the switching member is movably disposed in the ventilation channel. On its moving stroke, the switching member has a first sealing position, a second sealing position and a ventilation position between the first sealing position and the second sealing position. In the first sealing position, the switching member can seal the air inlet. In the second sealing position, the switching member can seal the air outlet. In the ventilation position, the switching member can open the air inlet and the air outlet. Through the movement of the switching member, not only can the pressure of the battery cell be released to the external space, but also the pressure inside the battery cell can quickly reach the opening pressure of the explosion-proof valve.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and particularly to a battery cell, a battery device, and an electrical equipment. Background Art

[0002] In recent years, new energy vehicles have achieved leapfrog development. In the field of electric vehicles, power batteries, as the power source of electric vehicles, play an irreplaceable and important role. With the strong promotion of new energy vehicles, the demand for power battery products is also increasing day by day. Among them, as the core component of new energy vehicles, the battery has relatively high requirements in terms of use reliability and service life.

[0003] In battery technology, to ensure the safety of the battery cell, a pressure relief device for discharging the internal pressure of the battery cell is generally provided on the housing of the battery cell, so that when the internal pressure or temperature of the battery cell reaches a threshold value, the pressure relief device can be actuated to discharge the internal pressure of the battery cell. However, after the pressure relief device discharges the pressure, the pressure inside the battery cell may be insufficient, resulting in the battery cell missing the opportunity to open the explosion-proof valve in the initial stage of thermal runaway. Summary of the Invention

[0004] The main purpose of the present application is to propose a battery cell, a battery device, and an electrical equipment, aiming to solve the problem that the pressure relief device of the battery cell affects the opening of the explosion-proof valve.

[0005] In a first aspect, the battery cell proposed by the present application includes:

[0006] A housing, which forms a receiving cavity and a ventilation channel communicating with the receiving cavity. The ventilation channel includes an air inlet and an air outlet, and a pole and an explosion-proof valve are provided on the housing; and,

[0007] A ventilation structure, including a switching member disposed in the ventilation channel. At least part of the switching member can be movably disposed in the ventilation channel. During its moving stroke, the switching member has a first sealing position, a second sealing position, and a ventilation position between the first sealing position and the second sealing position. In the first sealing position, the switching member can seal the air inlet. In the second sealing position, the switching member can seal the air outlet. In the ventilation position, the switching member can open the air inlet and the air outlet.

[0008] In the above technical solution, when the pressure inside the housing is small or there is no pressure, the switch member is in the first sealing position to close the air inlet of the air permeation channel, reducing the possibility of electrolyte leakage in the battery cell. When the pressure in the battery cell is medium, the switch member is in the air permeation position, and the switch member is in the middle of the air permeation channel, enabling the gas inside the housing to be discharged to the outside of the housing through the air permeation channel to reduce the pressure inside the housing. When the battery cell is in thermal runaway and the pressure rises sharply, the switch member is in the second sealing position to close the air outlet of the air permeation channel, allowing the gas to accumulate inside the housing, so that the pressure of the housing can quickly reach the opening pressure of the explosion-proof valve to open the explosion-proof valve. In this way, by setting the air permeation channel to connect the accommodation cavity with the external space of the housing, and through the movement of the switch member, not only can the pressure of the battery cell be released to the external space, reducing the risk of the battery cell bulging, but also the air permeation channel can be closed when the battery cell is in thermal runaway, enabling the gas to accumulate inside the battery cell, so that the pressure inside the battery cell can quickly reach the opening pressure of the explosion-proof valve, and the explosion-proof valve can be opened at the initial stage of thermal runaway, reducing the influence of the pressure relief of the air permeation structure on the opening of the explosion-proof valve.

[0009] In some embodiments, the switch member includes:

[0010] A sealing cylinder, arranged along the extending direction of the air permeation channel; and,

[0011] An outer sleeve, tapering from one end to the other end to have a small-diameter end and a large-diameter end. The small-diameter end is sleeved on the sealing cylinder, and the large-diameter end is connected to the inner wall of the air permeation channel;

[0012] Wherein, under the action of the air pressure at the air inlet, the outer sleeve can elastically deform along the extending direction of the air permeation channel, enabling the sealing cylinder to axially move in the air permeation channel along the outer sleeve to switch between the first sealing position, the air permeation position, and the second sealing position.

[0013] In the above technical solution, by setting the sealing cylinder, the air inlet or the air outlet of the air permeation channel can be sealed to prevent the gas inside the housing from escaping from the housing, and at the same time, the air inlet and the air outlet of the ventilation channel can be opened, enabling the gas inside the housing to flow out of the housing. By setting the outer sleeve, on the one hand, the sealing cylinder can be installed in the air permeation channel, and on the other hand, the housing can make the sealing cylinder move through the deformation of the outer sleeve itself and can be adaptively adjusted according to the pressure inside the housing, so that the deformation of the outer sleeve can be adapted to the pressure inside the housing.

[0014] In some embodiments, the small-diameter end is sleeved on one end of the sealing cylinder close to the air inlet;

[0015] The large-diameter end is correspondingly located at one end of the sealing cylinder close to the air outlet.

[0016] In the above technical solution, the small-diameter end is arranged at one end of the sealing cylinder close to the air inlet, and the large-diameter end is correspondingly arranged at one end of the sealing cylinder close to the air outlet, so that the outer sleeve is tapered in the direction from the air outlet to the air inlet, so that the switching member has a force towards the air inlet direction, so that the sealing cylinder can be tightly attached to the air inlet of the air-permeable channel, thereby helping to improve the sealing effect of the sealing cylinder.

[0017] In some embodiments, a stepped surface facing away from the air inlet is formed in the air-permeable channel, and the periphery of the large-diameter end overlaps on the stepped surface.

[0018] In the above technical solution, by setting the stepped surface, on the one hand, the installation position of the outer sleeve can be located in the air-permeable channel, which is convenient for quickly installing the outer sleeve in the air-permeable channel, and on the other hand, it is convenient to weld the outer sleeve to the inner wall surface of the air-permeable channel, reducing the risk of the outer sleeve separating from the air-permeable channel, which is beneficial to improving the reliability of the use of the switching member.

[0019] In some embodiments, the longitudinal section of the side wall of the outer sleeve is linearly arranged; or,

[0020] the longitudinal section of the side wall of the outer sleeve is convexly curved; or,

[0021] the longitudinal section of the side wall of the outer sleeve is concavely curved.

[0022] In the above technical solution, the longitudinal section of the side wall of the outer sleeve is linearly arranged, so that the force of the switching member on the air inlet is moderate, which can avoid both too large a force of the switching member on the air inlet, resulting in difficulty in opening the air inlet, and too small a force of the switching member on the air inlet, resulting in frequent opening of the air inlet and electrolyte leakage problems. In addition, compared with the outer sleeve with a linearly arranged side wall, the longitudinal section of the side wall of the outer sleeve is concavely curved, and its force on the air inlet of the air-permeable channel is larger, which can not only increase the sealing effect of the sealing cylinder on the air inlet, but also reduce the possibility of the air inlet being opened due to factors such as vibration. And the longitudinal section of the side wall of the outer sleeve is convexly curved, and its force on the air inlet of the air-permeable channel is smaller, making the outer sleeve easy to deform, facilitating the opening of the air inlet, which is beneficial to timely releasing the pressure in the housing and reducing the probability of the battery cell being under pressure.

[0023] In some embodiments, the switching member divides the air-permeable channel into a first air-permeable section and a second air-permeable section;

[0024] The battery cell further includes an air-permeable communication part connecting the first air-permeable section and the second air-permeable section.

[0025] In the above technical solution, by providing a breathable communication part to connect the two sides of the switch member, when the switch member is in the breathable position, the gas entering the breathable channel through the air inlet can flow through the breathable communication part to the air outlet and flow out of the breathable channel through the air outlet.

[0026] In some embodiments, the breathable communication part includes a communication channel provided on the housing, and the two channel openings of the communication channel communicate with the first breathable section and the second breathable section respectively.

[0027] In the above technical solution, by providing a communication channel to connect the breathable channels on both sides of the switch member, the gas entering the breathable channel through the air inlet can flow through the communication channel to the air outlet and flow out of the breathable channel through the air outlet.

[0028] In some embodiments, the switch member includes a sealing cylinder and an outer sleeve provided on the sealing cylinder;

[0029] The breathable communication part includes a communication hole penetrating through the outer sleeve.

[0030] In the above technical solution, by providing a communication hole to connect the breathable channels on both sides of the switch member, the gas entering the breathable channel through the air inlet can flow through the communication hole to the air outlet and flow out of the breathable channel through the air outlet.

[0031] In some embodiments, a sealing ring is provided at the air inlet and / or the air outlet.

[0032] In the above technical solution, by providing a sealing ring, when the switch member is in the first sealing position, the gap between the air inlet and the switch member is sealed, and when the switch member is in the second sealing position, the gap between the air outlet and the switch member is sealed, thereby helping to improve the sealing effect at the air inlet and the air outlet.

[0033] In some embodiments, a temperature-sensitive plug is provided at the air inlet and / or the air outlet.

[0034] In the above technical solution, usually, in order to prevent the electrolyte in the housing from leaking, it is necessary to block the air inlet and / or the air outlet of the breathable channel. However, when one of the battery cells in the battery box undergoes thermal runaway and rapidly heats up, the temperature of the surrounding adjacent battery cells will also increase, resulting in an increase in the pressure of the adjacent battery cells. Therefore, by providing a temperature-sensitive plug, when the adjacent battery cells are affected by the thermally runaway battery cell, the air inlet and the air outlet of the breathable channel are opened, so that the gas in the housing can flow out of the housing, realizing early pressure relief and reducing the influence of the adjacent battery cells by the thermally runaway battery cell.

[0035] In some embodiments, the melting point of the temperature-sensitive plug is T1, and the melting point of the housing is T2, where T1 < T2; and / or,

[0036] The material of the temperature-sensitive plug includes one of plastic or fluororubber.

[0037] In the above technical solution, the melting point of the temperature-sensitive plug is lower than that of the housing, so that the temperature-sensitive plug can melt in time on the premise of ensuring the safety of the housing, so as to open the air inlet and outlet of the ventilation channel. At the same time, since the temperature-sensitive plug is mainly used to block the air inlet or outlet of the ventilation channel and can open the air inlet and outlet when the battery cell is heated, the temperature-sensitive plug is made of temperature-sensitive materials such as plastic or fluororubber, so that the temperature-sensitive plug can melt in time when heated, so as to open the air inlet and outlet of the ventilation channel.

[0038] In some embodiments, T1 ≤ 400 °C.

[0039] In the above technical solution, since the melting point of the housing is relatively high, even if the melting point of the temperature-sensitive plug is lower than that of the housing, it may exceed the allowable temperature of the battery cell. Therefore, T1 ≤ 400 °C, so that the temperature-sensitive plug can melt in time to open the air inlet and outlet of the ventilation channel, so as to prevent the temperature of the battery cell from exceeding its allowable temperature.

[0040] In some embodiments, the housing includes a housing body and a top cover covering the housing body, and the housing body and the top cover jointly enclose the accommodation cavity;

[0041] Wherein, the ventilation channel and the pole are both arranged on the top cover.

[0042] In the above technical solution, by providing the housing body and the top cover, it is convenient to install the bare battery cell. At the same time, since gas usually accumulates at the upper end of the accommodation cavity, the ventilation channel is arranged on the top cover so that the gas in the accommodation cavity can be discharged in time through the ventilation channel, reducing the possibility of gas accumulation in the housing.

[0043] In some embodiments, the top cover includes a cover body and a lid covering the cover body, and the cover body and the lid jointly enclose an installation cavity, and the switching member is installed in the installation cavity;

[0044] Wherein, the ventilation channel includes the installation cavity.

[0045] In the above technical solution, by providing the lid and the cover body, an installation cavity can be formed, which can enlarge the size of the ventilation channel and facilitate the installation of the switching member.

[0046] In a second aspect, the present application further provides a battery device, and the battery device includes the above battery cell.

[0047] In a third aspect, the present application also provides an electrical device, which includes the above-mentioned battery device. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0049] Figure 1 Schematic structural diagram of the first embodiment of the battery cell provided by the present application;

[0050] Figure 2 Schematic structural diagram of the second embodiment of the battery cell provided by the present application;

[0051] Figure 3 For Figure 2 Cross-sectional structural diagram of the first embodiment of the breathable structure in

[0052] Figure 4 For Figure 2 Cross-sectional structural diagram of the second embodiment of the breathable structure in

[0053] Figure 5 For Figure 2 Cross-sectional structural diagram of the third embodiment of the breathable structure in

[0054] Figure 6 For Figure 2 Cross-sectional structural diagram of the fourth embodiment of the breathable structure in

[0055] Figure 7 For Figure 2 Cross-sectional structural diagram of the fifth embodiment of the breathable structure in

[0056] Figure 8 Schematic structural diagram of the third embodiment of the battery cell provided by the present application;

[0057] Figure 9 For Figure 8 Local enlarged view of part A in

[0058] Figure 10 For Figure 8 Cross-sectional structural diagram of the battery cell in

[0059] Figure 11 For Figure 10 Local enlarged view of part B in

[0060] Figure 12 Schematic structural diagram of the fourth embodiment of the battery cell provided by this application;

[0061] Figure 13 is Figure 12 Partial enlarged view of position C in

[0062] Figure 14 is Figure 12 Schematic cross-sectional structure diagram of the battery cell in

[0063] Figure 15 is Figure 14 Partial enlarged view of position D in

[0064] Figure 16 Schematic structural diagram of the fifth embodiment of the battery cell provided by this application;

[0065] Figure 17 is Figure 16 Schematic cross-sectional structure diagram of the battery cell in

[0066] Figure 18 is Figure 17 Partial enlarged view of position E in

[0067] Figure 19 Schematic structural diagram of the sixth embodiment of the battery cell provided by this application;

[0068] Figure 20 is Figure 19 Schematic cross-sectional structure diagram of the battery cell in

[0069] Figure 21 is Figure 20 Partial enlarged view of position F in

[0070] Figure 22 Schematic structural diagram of the seventh embodiment of the battery cell provided by this application;

[0071] Figure 23 Schematic structural diagram of an embodiment where the electrical device provided by this application is a vehicle.

[0072] Explanation of the reference numerals in the drawings:

[0073] 1000, vehicle;

[0074] 100, battery device; 200, controller; 300, motor;

[0075] 400. Battery cell; 1. Housing; 11. Housing body; 12. Top cover; 121. Cover body; 122. Cover; 13. Accommodation cavity; 14. Ventilation channel; 141. Air inlet; 142. Air outlet; 143. Installation cavity; 144. Step surface; 145. First ventilation section; 146. Second ventilation section; 2. Ventilation structure; 21. Switching member; 211. Sealing cylinder; 212. Outer sleeve; 2121. Longitudinal section; 2122. Large-diameter end; 2123. Small-diameter end; 3. Ventilation connection part; 31. Connecting channel; 32. Connecting hole; 4. Sealing ring; 5. Temperature-sensitive plug.

[0076] The realization of the purpose of this application, its functional features and advantages will be further described in conjunction with the embodiments and with reference to the accompanying drawings. Detailed implementation manners

[0077] The embodiments of the technical solution of this application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solution of this application more clearly, and thus are only examples and should not be used to limit the protection scope of this application.

[0078] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the description and claims of this application and the above drawings are intended to cover non-exclusive inclusion.

[0079] In the description of the embodiments of this application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order or primary-secondary relationship of the indicated technical features. In the description of the embodiments of this application, "a plurality of" means two or more, unless otherwise specifically defined.

[0080] Referring to "embodiments" herein means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of this application. The phrase appears in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0081] In the description of the embodiments of this application, the term "a plurality of" means two or more (including two). Similarly, "a plurality of groups" means two or more groups (including two groups), and "a plurality of sheets" means two or more sheets (including two sheets).

[0082] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0083] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0084] In recent years, new energy vehicles have developed by leaps and bounds. In the field of electric vehicles, power batteries, as the power source of electric vehicles, play an irreplaceable and important role. With the vigorous promotion of new energy vehicles, the demand for power battery products is also growing. Among them, batteries, as core components of new energy vehicles, have high requirements in terms of reliability and service life.

[0085] In battery technology, in order to prevent the internal thermal runaway of the battery from causing an explosion, an explosion-proof valve is usually set on the battery cell. When an abnormality occurs in the battery cell and the internal thermal runaway of the battery cell causes a sharp increase in temperature and pressure, the gas generated in the battery cell will break through the notched area of ​​the explosion-proof valve, causing the explosion-proof valve to explode, thereby achieving the purpose of pressure relief. However, the battery cell will also generate heat during normal use, which will increase the pressure inside the battery cell, easily causing swelling, causing mutual squeezing between battery cells, and affecting the reliability of the system. Therefore, in order to ensure the safety of the battery cell, a pressure relief device for releasing the internal pressure of the battery cell is generally set on the shell of the battery cell, so that when the internal pressure or temperature of the battery cell reaches a threshold, the pressure relief device can be actuated to release the pressure inside the battery cell. However, the pressure relief device will continuously release the pressure inside the battery cell. When the battery cell is in thermal runaway, the pressure inside the battery cell may be insufficient, causing the battery cell to miss the opportunity to open the explosion-proof valve at the beginning of thermal runaway.

[0086] Analyzing the causes of the above problems, it can be seen that in the existing battery cells, the pressure relief device on the battery cell can release the pressure inside the battery cell under normal conditions. However, in abnormal situations such as thermal runaway, it may cause the battery cell to miss the opportunity to open the explosion-proof valve at the initial stage of thermal runaway, affecting the opening of the explosion-proof valve. To solve the problem that the pressure relief device affects the opening of the explosion-proof valve, an attempt can be made to improve the structure of the pressure relief device so that it can both release the pressure inside the battery cell and not affect the opening of the explosion-proof valve.

[0087] In this application, the battery cell can include a primary lithium-ion battery cell, a secondary lithium-ion battery cell, a lithium-sulfur battery cell, a sodium-lithium-ion battery cell, a sodium-ion battery cell, a magnesium-ion battery cell, etc., and the embodiments of this application are not limited thereto. The battery cell can be in the shape of a cylinder, a flat body, a cuboid, or other shapes, and the embodiments of this application are not limited thereto either. Generally, the battery cells are divided into three types according to the packaging method: cylindrical battery cells, square battery cells, and soft-pack battery cells, and the embodiments of this application are not limited thereto either.

[0088] The battery cell includes an electrode assembly and an electrolyte. The electrode assembly is composed of a positive electrode sheet, a negative electrode sheet, and a separator. The battery cell mainly operates by the movement of metal ions between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode current collector. The current collector without the coated positive electrode active material layer protrudes from the current collector with the coated positive electrode active material layer. The current collectors without the coated positive electrode active material layer are stacked to form a positive electrode tab. Taking a lithium-ion battery as an example, the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobaltate, lithium iron phosphate, ternary lithium, or lithium manganate, etc. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector. The current collector without the coated negative electrode active material layer protrudes from the current collector with the coated negative electrode active material layer. The current collectors without the coated negative electrode active material layer are stacked to form a negative electrode tab. The material of the negative electrode current collector can be copper, and the negative electrode active material can be carbon or silicon, etc. The material of the separator can be PP (polypropylene) or PE (polyethylene), etc. In addition, the electrode assembly can be a wound structure or a stacked structure, and the embodiments of this application are not limited thereto.

[0089] To facilitate the understanding of the battery cell provided in this application, the following is described with reference to the accompanying drawings. Figure 1 Schematic diagram of the three-dimensional structure of the first embodiment of the battery cell provided in this application; Figure 2 Exploded structure schematic diagram of the second embodiment of the battery cell provided in this application; Figures 3 to 7 For Figure 2 the cross-sectional structure schematic diagram of the gas-permeable structure of the battery cell in Figure 8Exploded structural schematic diagram of the third embodiment of the battery cell provided by this application; Figure 9 is Figure 8 partial enlarged structural schematic diagram of part A in Figure 10 is Figure 8 cross-sectional structural schematic diagram of the battery cell in Figure 11 is Figure 10 partial enlarged structural schematic diagram of part B in Figure 12 Exploded structural schematic diagram of the fourth embodiment of the battery cell provided by this application; Figure 13 is Figure 12 partial enlarged structural schematic diagram of part C in Figure 14 is Figure 12 cross-sectional structural schematic diagram of the battery cell in Figure 15 is Figure 14 partial enlarged structural schematic diagram of part D in Figure 16 Exploded structural schematic diagram of the fifth embodiment of the battery cell provided by this application; Figure 17 is Figure 16 cross-sectional structural schematic diagram of the battery cell in Figure 18 is Figure 17 partial enlarged structural schematic diagram of part E in Figure 19 Exploded structural schematic diagram of the sixth embodiment of the battery cell provided by this application; Figure 20 is Figure 19 cross-sectional structural schematic diagram of the battery cell in Figure 21 is Figure 19 partial enlarged structural schematic diagram of part F in Figure 22 Exploded structural schematic diagram of the seventh embodiment of the battery cell provided by this application; Figure 23 Structural schematic diagram of an embodiment where the electrical device provided by this application is a vehicle.

[0090] Please refer to Figures 1 to 5 , in an embodiment of this application, the battery cell 400 includes a housing 1 and a ventilation structure 2. The housing 1 forms a receiving cavity 13 and a ventilation channel 14 communicating with the receiving cavity 13. The ventilation channel 14 includes an air inlet 141 and an air outlet 142. The housing 1 is provided with a terminal and an explosion-proof valve. The ventilation structure 2 includes a switching member 21 disposed in the ventilation channel 14. The switching member 21 is at least partially movably disposed in the ventilation channel 14. In its moving stroke, the switching member 21 has a first sealing position, a second sealing position, and a ventilation position between the first sealing position and the second sealing position. In the first sealing position, the switching member 21 can seal the air inlet 141. In the second sealing position, the switching member 21 can seal the air outlet 142. In the ventilation position, the switching member 21 can open the air inlet 141 and the air outlet 142.

[0091] It should be noted that the housing 1 is a main loading component of the battery cell 400. The battery cell 400 is installed in the box body of the battery device 100 through the housing 1, and at the same time, the bare battery core is installed through the accommodation cavity 13 of the housing 1. There are various shapes of the housing 1. The housing 1 can be a cylinder, a prism, or a cuboid, etc. The embodiments of the present application do not limit this. There are various materials of the housing 1. The material of the housing 1 can be a metal housing, such as an iron housing, a steel housing, an aluminum alloy housing, etc., or an inorganic non-metallic housing, such as a ceramic housing, etc. The embodiments of the present application do not limit this.

[0092] The ventilation channel 14 includes an air inlet 141 and an air outlet 142. The air inlet 141 of the ventilation channel 14 is communicated with the accommodation cavity 13 of the housing 1, and the air outlet 142 of the ventilation channel 14 is communicated with the external space of the housing 1, so that the gas in the accommodation cavity 13 can be discharged to the outside of the housing 1 through the ventilation channel 14, in order to release the pressure in the housing 1 and reduce the risk of the housing 1 bulging. There are various shapes of the ventilation channel 14, which can be circular or polygonal, etc. The embodiments of the present application do not limit this.

[0093] The switching member 21 is arranged in the ventilation channel 14 and at least part of it can move in the ventilation channel 14, mainly used to seal or open the air inlet 141 or the air outlet 142 of the ventilation channel 14. There are various shapes of it, which can be circular or polygonal, etc. The embodiments of the present application do not limit this.

[0094] It should also be noted that on the moving stroke of the switching member 21, the switching member 21 has a first sealing position, a second sealing position, and a ventilation position between the first sealing position and the second sealing position. When the switching member 21 is in the first sealing position, please refer to Figure 3 At this time, the pressure in the housing 1 is small or there is no pressure. The switching member 21 is located at the air inlet 141 of the ventilation channel 14 to close the air inlet 141 of the ventilation channel 14. When the switching member 21 is in the ventilation position, please refer to Figure 4 At this time, the pressure in the housing 1 is medium. The switching member 21 is between the air inlet 141 and the air outlet 142, and the gas can flow out of the housing 1 through the ventilation channel 14. When the switching member 21 is in the second sealing position, please refer to Figure 5 At this time, the pressure in the housing 1 is large. The switching member 21 is at the outlet of the ventilation channel 14 to close the air outlet 142 of the ventilation channel 14, so that the gas can accumulate in the housing 1, so that the pressure in the housing 1 can quickly reach the opening pressure of the explosion-proof valve.

[0095] The terminal post is arranged on the housing 1 and is used to transfer the electric energy inside the battery to the external circuit, or transfer the electric energy of the external circuit to the inside of the battery for charging. One end of it is directly connected to the bus bar, and the other end is connected to an external conductor or to one pole of an adjacent single battery in the battery pack. The explosion-proof valve is arranged on the housing 1 and is used to protect the battery cell 400 from exploding under abnormal conditions. It is a safety protection device that can automatically open the valve and release the internal pressure when the pressure inside the housing 1 is too high, so as to prevent the battery cell 400 from exploding.

[0096] In the technical solution of the present application, when the pressure inside the housing 1 is small or there is no pressure, the switching member 21 is in the first sealing position to close the air inlet 141 of the air permeation channel 14, reducing the possibility of electrolyte leakage of the battery cell 400. When the pressure inside the battery cell 400 is medium, the switching member 21 is in the air permeation position, and the switching member 21 is in the middle of the air permeation channel 14, so that the gas inside the housing 1 can be discharged to the outside of the housing 1 through the air permeation channel 14 to reduce the pressure inside the housing 1. When the battery cell 400 is in thermal runaway and the pressure rises sharply, the switching member 21 is in the second sealing position to close the air outlet 142 of the air permeation channel 14, so that the gas can accumulate inside the housing 1, so that the pressure inside the housing 1 can quickly reach the opening pressure of the explosion-proof valve, so that the explosion-proof valve opens. In this way, by providing the air permeation channel 14 to communicate the accommodation cavity 13 with the external space of the housing 1, and through the movement of the switching member 21, not only can the pressure of the battery cell 400 be released to the external space, reducing the risk of the battery cell 400 bulging, but also the air permeation channel 14 can be closed when the battery cell 400 is in thermal runaway, so that the gas accumulates inside the battery cell 400, so that the pressure inside the battery cell 400 can quickly reach the opening pressure of the explosion-proof valve, so that the explosion-proof valve can open at the initial stage of thermal runaway, reducing the influence of the pressure relief of the air permeation structure 2 on the opening of the explosion-proof valve.

[0097] In some embodiments of the present application, please refer to Figure 2 and Figure 3 , the switching member 21 includes a sealing cylinder 211 and an outer sleeve 212. The sealing cylinder 211 is arranged along the extending direction of the air permeation channel 14. The outer sleeve 212 is tapered from one end to the other end to have a small-diameter end 2123 and a large-diameter end 2122. The small-diameter end 2123 is sleeved on the sealing cylinder 211, and the large-diameter end 2122 is connected to the inner wall of the air permeation channel 14. Among them, under the action of the air pressure at the air inlet 141, the outer sleeve 212 can elastically deform along the extending direction of the air permeation channel 14, so that the sealing cylinder 211 can move axially along the outer sleeve 212 in the air permeation channel 14 to switch between the first sealing position, the air permeation position and the second sealing position.

[0098] It should be noted that for the convenience of the movement of the sealing cylinder 211, the material of the outer sleeve 212 of the switch member 21 is an elastic material, so that the sealing cylinder 211 can move through the deformation of the switch member 21 itself. Moreover, the greater the pressure inside the housing 1, the greater the deformation of the switch member 21, enabling the deformation of the switch member 21 to be adaptively adjusted according to the pressure inside the housing, so as to match the pressure inside the housing 1. Further, there are various elastic materials, which can be plastic materials, such as the plastic switch member 21, or rubber materials, such as the rubber switch member 21, etc. As long as it can be adaptively adjusted according to the pressure inside the housing 1, the embodiments of the present application do not make limitations in this regard.

[0099] The sealing cylinder 211 is movably arranged in the air permeation channel 14, so that one end close to the air inlet 141 can tightly adhere to the air inlet 141 of the air permeation channel 14 to close the air inlet 141 of the air permeation channel 14, or one end close to the air outlet 142 can tightly adhere to the air outlet 142 to close the air outlet 142 of the air permeation channel 14, or both ends are simultaneously separated from the air inlet 141 and the air outlet 142, enabling the air flow inside the housing 1 to flow to the external space of the housing 1. The sealing cylinder 211 extends along the extension direction of the air permeation channel 14 to increase the length of the sealing cylinder 211 and reduce the movement stroke of the sealing cylinder 211. Among them, the shape of the sealing cylinder 211 is various. The sealing cylinder 211 can be a cylinder or a prism, etc. The embodiments of the present application do not make limitations in this regard. Further, in order to ensure the sealing effect of the sealing cylinder 211, usually the size of the sealing cylinder 211 needs to be larger than the size of the air inlet 141 or the air outlet 142. However, this will increase the cost of the sealing cylinder 211. Therefore, the sealing cylinder 211 includes a column body and sealing flanges provided at both ends of the column body, so as to reduce the size of the sealing cylinder 211 on the premise of ensuring the central sealing effect, thereby facilitating the reduction of the cost of the sealing cylinder 211.

[0100] The small-diameter end 2123 of the outer sleeve 212 refers to the end where the distance from the periphery of the outer sleeve 212 to its central axis is smaller, which is used to connect the sealing cylinder 211. The large-diameter end 2122 of the outer sleeve 212 is the end where the distance from the periphery of the outer sleeve 212 to its central axis is larger, which is used to connect the inner wall surface of the air permeation channel 14. For details, please refer to Figure 3Further, the outer jacket 212 can be circularly arranged, or polygonally arranged, etc., and the embodiments of the present application do not limit this. In particular, the outer jacket 212 and the sealing column 211 can be integrally arranged or separately arranged, and the embodiments of the present application do not limit this. Since the ventilation channel 14 is used to release the pressure in the housing 1 and its structure is relatively small, the switch member 21 is also relatively small. If the outer jacket 212 and the sealing column 211 are assembled separately, it will be more cumbersome and difficult. Therefore, the outer jacket 212 and the sealing column 211 are preferably integrally formed to save the subsequent assembly process and assembly time. Further, the materials of the outer jacket 212 and the sealing column 211 can be the same or different, and the embodiments of the present application do not limit this. However, for the convenience of integral forming, the materials of the outer jacket 212 and the sealing column 211 are preferably the same material. In addition, there are various connection methods between the outer jacket 212 and the inner wall surface of the ventilation channel 14. The outer jacket 212 and the inner wall surface of the ventilation channel 14 can be connected by welding or bonding, etc., and the embodiments of the present application do not limit this. However, since the movement of the sealing column 211 is realized by the deformation of the outer jacket 212, the outer jacket 212 is prone to looseness during long-term use. Therefore, the outer jacket 212 is welded to the inner wall surface of the ventilation channel 14 to strengthen the connection between the outer jacket 212 and the inner wall surface of the ventilation channel 14, reduce the risk of the outer jacket 212 separating from the inner wall surface of the ventilation channel 14, and is beneficial to improving the reliability of the use of the switch member 21.

[0101] In the above technical solution, by providing the sealing column 211, it is possible to seal both the air inlet 141 or the air outlet 142 of the ventilation channel 14 to prevent the gas in the housing 1 from escaping from the housing 1, and at the same time, it is possible to open both the air inlet 141 and the air outlet 142 of the ventilation channel, so that the gas in the housing 1 can flow out of the housing 1. By providing the outer jacket 212, on the one hand, the sealing column 211 can be installed in the ventilation channel 14, and on the other hand, the housing 1 can make the sealing column 211 move through the deformation of the outer jacket 212 itself, and can be adaptively adjusted according to the pressure in the housing 1, so that the deformation of the outer jacket 212 can be adapted to the pressure in the housing 1.

[0102] In the above embodiment, there are various setting positions of the small-diameter end 2123 of the outer jacket 212. The small-diameter end 2123 can be set at one end of the sealing column 211 close to the air outlet 142, or can be set at one end of the sealing column 211 close to the air inlet 141, and the embodiments of the present application do not limit this. However, if the small-diameter end 2123 is set at one end of the sealing column 211 close to the air outlet 142, the pressure of the outer jacket 212 is insufficient when the sealing column 211 is in the first sealing position, which may cause the air inlet 141 to be not tightly sealed. Therefore, in this embodiment, please refer to Figures 3 to 7, the small-diameter end 2123 is sleeved on one end of the sealing cylinder 211 close to the air inlet 141, and the large-diameter end 2122 is correspondingly located at one end of the sealing cylinder 211 close to the air outlet 142.

[0103] In the above technical solution, the small-diameter end 2123 is arranged at one end of the sealing cylinder 211 close to the air inlet 141, and the large-diameter end 2122 is correspondingly arranged at one end of the sealing cylinder 211 close to the air outlet 142, so that the outer sleeve 212 is tapered in the direction from the air outlet 142 to the air inlet 141, so that the switching member 21 has a force towards the air inlet 141, so that the sealing cylinder 211 can be tightly attached to the air inlet 141 of the air-permeable channel 14, thereby helping to improve the sealing effect of the sealing cylinder 211.

[0104] In an embodiment of the present application, a stepped surface 144 facing away from the air inlet 141 is formed in the air-permeable channel 14, and the periphery of the large-diameter end 2122 is lapped on the stepped surface 144.

[0105] It should be noted that, from the air inlet 141 of the air-permeable channel 14 towards its air outlet 142, the inner wall surface of the air-permeable channel 14 is constricted to form a stepped surface 144 facing the air outlet 142, so as to locate the position of the outer sleeve 212 in the air-permeable channel 14. Of course, in other embodiments, the position of the outer sleeve 212 can also be located by an annular groove provided in the air-permeable channel 14, but this method is not convenient for welding the outer sleeve 212 to the inner wall surface of the air-permeable channel 14.

[0106] In the above technical solution, by providing the stepped surface 144, on the one hand, the installation position of the outer sleeve 212 can be located in the air-permeable channel 14, which is convenient for quickly installing the outer sleeve 212 in the air-permeable channel 14. On the other hand, it is convenient to weld the outer sleeve 212 to the inner wall surface of the air-permeable channel 14, reducing the risk of the outer sleeve 212 detaching from the air-permeable channel 14, which is beneficial to improving the reliability of the switching member 21.

[0107] In an embodiment of the present application, please refer to Figure 6 , the longitudinal section 2121 of the side wall of the outer sleeve 212 is linearly arranged.

[0108] It should be noted that the longitudinal section 2121 of the side wall of the outer sleeve 212 refers to two cross-sections of the outer sleeve 212 in the cross-section along the extending direction of the air-permeable channel 14. Specifically, please refer to Figure 6 , in the cross-section along the extending direction of the air-permeable channel 14, the longitudinal section 2121 of the side wall of the outer sleeve 212 is linearly arranged.

[0109] In the above technical solution, the longitudinal section 2121 of the side wall of the outer casing 212 is arranged in a straight line, so that the acting force of the switching member 21 on the air inlet 141 is moderate. It can not only prevent the acting force of the switching member 21 on the air inlet 141 from being too large, resulting in difficulty in opening the air inlet 141, but also avoid the acting force of the switching member 21 on the air inlet 141 from being too small, causing the air inlet 141 to open frequently, leading to the problem of electrolyte leakage.

[0110] In an embodiment of the present application, please refer to Figures 3 to 5 , the longitudinal section 2121 of the side wall of the outer casing 212 is arranged in a concave curved shape.

[0111] It should be noted that the longitudinal section 2121 of the side wall of the outer casing 212 being arranged in a concave curved shape means that the outer casing 212 is recessed towards the direction close to its center, specifically as shown in Figure 3 and Figure 4 shown.

[0112] In the above technical solution, compared with the outer casing 212 arranged in a straight line, the longitudinal section 2121 of the side wall of the outer casing 212 is arranged in a concave curved shape, and its acting force on the air inlet 141 of the air permeable channel 14 is relatively large, which can not only increase the sealing effect of the sealing column 211 on the air inlet 141, but also reduce the possibility of the air inlet 141 being opened due to factors such as vibration.

[0113] In an embodiment of the present application, please refer to Figure 7 , the longitudinal section 2121 of the side wall of the outer casing 212 is arranged in a convex curved shape.

[0114] It should be noted that the longitudinal section 2121 of the side wall of the outer casing 212 being arranged in a convex curved shape means that the outer casing 212 protrudes towards the direction away from its center, specifically as shown in Figure 7 shown.

[0115] In the above technical solution, compared with the outer casing 212 arranged in a straight line, the longitudinal section 2121 of the side wall of the outer casing 212 is arranged in a convex curved shape, and its acting force on the air inlet 141 of the air permeable channel 14 is relatively small, making the outer casing 212 prone to deformation, facilitating the opening of the air inlet 141, being beneficial to timely releasing the pressure in the housing 1, and reducing the probability of the battery cell 400 being under pressure.

[0116] It should also be noted that, please refer to Figures 3 to 7 , due to the different shapes of the outer casing 212, the acting force of the switching member 21 on the air inlet 141 will also be different. Therefore, by replacing the outer casing 212 with different shapes, the switching member 21 can be adapted to battery cells 400 with different pressures, which is beneficial to improving the versatility of the air permeable structure 2.

[0117] In an embodiment of the present application, please refer toFigure 8 and Figure 12 The switch member 21 divides the ventilation channel into a first ventilation section 145 and a second ventilation section 146. The battery cell further includes a ventilation connection part 3 that connects the first ventilation section 145 and the second ventilation section 146.

[0118] It should be noted that since the switch member 21 is disposed in the ventilation channel 14 to isolate the ventilation channel 14, the gas in the housing 1 cannot flow out of the housing 1 through the ventilation channel 14. Therefore, in this embodiment, by providing the ventilation connection part 3, the two sides of the switch member 21 are connected, so that when the switch member 21 is in the ventilation position, the gas entering the ventilation channel 14 through the air inlet 141 can flow through the ventilation connection part 3 to the air outlet 142 and flow out of the ventilation channel 14 through the air outlet 142.

[0119] In the above embodiment, there are various ways to set the ventilation connection part 3. In an embodiment of the present application, please refer to Figures 8 to 11 , the ventilation connection part 3 includes a communication channel 31 provided in the housing 1, and the two channel openings of the communication channel 31 communicate with the first ventilation section 145 and the second ventilation section 146 respectively.

[0120] It should be noted that the shape of the communication channel 31 has various forms, which can be circular or rectangular, etc., as long as it can connect the ventilation channels 14 on both sides of the switch member 21. The embodiments of the present application do not limit this. Further, the number of the communication channels 31 has various forms, which can be one or multiple, etc. The embodiments of the present application do not limit this. Specifically, a plurality of communication channels 31 are provided, and the plurality of communication channels 31 are arranged at intervals along the circumferential direction of the ventilation channel 14. By providing a plurality of communication channels 31, the ventilation area of the ventilation connection part 3 can be increased, so that the gas can quickly pass through the switch member 21.

[0121] In the above technical solution, by providing the communication channel 31, the ventilation channels 14 on both sides of the switch member 21 are connected, so that the gas entering the ventilation channel 14 through the air inlet 141 can flow through the communication channel 31 to the air outlet 142 and flow out of the ventilation channel 14 through the air outlet 142.

[0122] In the above embodiment, although setting the communication channel 31 can connect the ventilation channels 14 on both sides of the switch member 21, this method has a relatively high forming difficulty. Therefore, in another embodiment of the present application, please refer to Figures 12 to 15 , the switch member 21 includes a sealing cylinder 211 and an outer sleeve 212 provided on the sealing cylinder 211, and the ventilation connection part 3 includes a communication hole 32 penetrating through the outer sleeve 212.

[0123] It should be noted that the shape of the communication hole 32 can be various, such as circular or rectangular, as long as it can connect the ventilation channels 14 on both sides of the switch member 21. The embodiments of the present application do not limit this. Further, the number of the communication holes 32 can be various, such as one or multiple, etc. The embodiments of the present application do not limit this. Specifically, a plurality of communication holes 32 are provided, and the plurality of communication holes 32 are arranged at intervals along the circumferential direction of the ventilation channel 14. By providing a plurality of communication holes 32, the ventilation area of the ventilation connection part 3 is increased, so that gas can quickly pass through the switch member 21.

[0124] In the above technical solution, by providing the communication hole 32, the ventilation channels 14 on both sides of the switch member 21 are connected, so that the gas entering the ventilation channel 14 through the air inlet 141 can flow to the air outlet 142 through the communication hole 32 and flow out of the ventilation channel 14 through the air outlet 142.

[0125] In an embodiment of the present application, please refer to Figure 16 and Figure 18 , a sealing ring 4 is provided at the air inlet 141 and / or the air outlet 142.

[0126] It should be noted that the setting method of the sealing ring 4 can be various. The sealing ring 4 can be provided only at the air inlet 141, or only at the air outlet 142, or the sealing ring 4 can be provided at both the air inlet 141 and the air outlet 142. The embodiments of the present application do not limit this. Among them, the material of the sealing ring 4 can be various. The material of the sealing ring 4 can be rubber or silica gel, etc. The embodiments of the present application do not limit this. Further, a sink is provided in the ventilation channel 14, and the sealing ring 4 is arranged in the sink. Among them, the bottom of the sink communicates with the air inlet 141 and the air outlet 142 of the ventilation channel 14. By providing the sink, the position of the sealing ring 4 is located in the ventilation channel 14, so as to quickly install the sealing ring 4 at the air inlet 141 or the air outlet 142.

[0127] In the above technical solution, by providing the sealing ring 4, when the switch member 21 is in the first sealing position, the gap between the air inlet 141 and the switch member 21 is sealed, and when the switch member 21 is in the second sealing position, the gap between the air outlet 142 and the switch member 21 is sealed, thereby helping to improve the sealing effect at the air inlet and the air outlet 142.

[0128] In an embodiment of the present application, please refer to Figure 19 and Figure 21 , a temperature-sensitive plug 5 is provided at the air inlet 141 and / or the air outlet 142.

[0129] It should be noted that the temperature-sensitive plug 5 is a temperature-sensitive plug or a thermosensitive plug, which is a device that changes its physical state at a specific temperature. Usually, the temperature-sensitive plug 5 is used to block the air inlet 141 and / or the air outlet 142 of the air-permeable channel 14. When the preset temperature is reached, the temperature-sensitive plug 5 will undergo a phase change (such as changing from a solid state to a liquid state), so that the air inlet 141 and the air outlet 142 are opened, enabling the gas in the housing 1 to flow out of the housing 1 through the air-permeable channel 14. Further, there are various ways to set the temperature-sensitive plug 5. It can be set only at the air inlet 141, or only at the air outlet 142, or at both the air inlet 141 and the air outlet 142 at the same time. The embodiments of the present application do not limit this.

[0130] In the above technical solution, usually, in order to prevent the electrolyte in the housing 1 from leaking, it is necessary to block the air inlet 141 and / or the air outlet 142 of the air-permeable channel 14. However, when one of the battery cells 400 in the battery box undergoes thermal runaway and the temperature rises sharply, the temperature of the adjacent battery cells 400 will also increase, resulting in an increase in the pressure of the adjacent battery cells 400. Therefore, by setting the temperature-sensitive plug 5, when the adjacent battery cells 400 are affected by the battery cell 400 with thermal runaway, the air inlet 141 and the air outlet 142 of the air-permeable channel 14 can be opened in time, enabling the gas in the housing 1 to flow out of the housing 1, realizing early pressure relief and reducing the influence of the battery cell 400 with thermal runaway on the adjacent battery cells 400.

[0131] In an embodiment of the present application, the melting point of the temperature-sensitive plug 5 is T1, and the melting point of the housing 1 is T2, where T1 < T2.

[0132] In the above technical solution, the melting point of the temperature-sensitive plug 5 is lower than that of the housing 1, so that the temperature-sensitive plug 5 can melt in time to open the air inlet 141 and the air outlet 142 of the air-permeable channel 14 on the premise of ensuring the safety of the housing 1.

[0133] In an embodiment of the present application, the material of the temperature-sensitive plug 5 includes one of plastic or fluororubber.

[0134] It should be noted that the material of the temperature-sensitive plug 5 including one of plastic or fluororubber means that the temperature plug can be a plug made of one of plastic or fluororubber, such as a plastic plug or a fluororubber plug. Of course, the temperature-sensitive plug 5 can also be a plug made of other temperature-sensitive materials, as long as it can melt when heated. The embodiments of the present application do not limit this.

[0135] In the above technical solution, since the temperature-sensitive plug 5 is mainly used to block the air inlet 141 or the air outlet 142 of the air-permeable channel 14 and can open the air inlet 141 and the air outlet 142 when the battery cell 400 is heated, the temperature-sensitive plug 5 is made of a temperature-sensitive material such as plastic or fluororubber, so that the temperature-sensitive plug 5 can be melted in time when heated, so as to open the air inlet 141 and the air outlet 142 of the air-permeable channel 14.

[0136] It should be noted that the above two related technical features: "T1 < T2" and "the material of the temperature-sensitive plug 5 includes one of plastic or fluororubber" can be set alternatively or simultaneously. Obviously, setting them simultaneously has a better effect.

[0137] In an embodiment of the present application, T1 ≤ 400°C.

[0138] In the above technical solution, since the melting point of the housing 1 is relatively high, even if the melting point of the temperature-sensitive plug 5 is lower than that of the housing 1, it may still exceed the allowable temperature of the battery cell 400. Therefore, T1 ≤ 400°C, so that the temperature-sensitive plug 5 can be melted in time to open the air inlet 141 and the air outlet 142 of the air-permeable channel 14, so as to prevent the temperature of the battery cell 400 from exceeding its allowable temperature.

[0139] In an embodiment of the present application, please refer to Figure 1 , the housing 1 includes a housing body 11 and a top cover 12 covering the housing body 11. The housing body 11 and the top cover 12 together define an accommodation cavity 13. Among them, the air-permeable channel 14 and the pole post are both arranged on the top cover 12.

[0140] It should be noted that there are various installation positions of the air-permeable channel 14. The air-permeable channel 14 can be arranged on the housing body 11 or on the top cover 12. The embodiments of the present application do not limit this. Among them, there are various connection methods between the housing body 11 and the top cover 12. The top cover 12 can be installed on the housing body 11 by welding, or by bonding, or by screws, etc., as long as the top cover 12 can be fixed on the housing body 11. The embodiments of the present application do not limit this.

[0141] In the above technical solution, by providing the housing body 11 and the top cover 12, it is convenient to install the bare battery cell. At the same time, since gas usually accumulates at the upper end of the accommodation cavity 13, the air-permeable channel 14 is arranged on the top cover 12, so that the gas in the accommodation cavity 13 can be discharged in time through the air-permeable channel 14, reducing the possibility of gas accumulation in the housing 1.

[0142] In an embodiment of the present application, please refer to Figure 2 , Figure 8 and Figure 12The top cover 12 includes a cover body 121 and a cover body 122 which is covered on the cover body 121 . The cover body 121 and the cover body 122 together form an installation cavity 143 . The switch element 21 is installed in the installation cavity 143 . The air permeable channel 14 includes the installation cavity 143 .

[0143] It should be noted that there are many ways to connect the cover body 121 and the cover body 122. The cover body 122 can be installed on the cover body 121 by welding, or by bonding, or by screws, etc. As long as the cover body 122 can be fixed on the cover body 121, the embodiment of the present application does not limit this.

[0144] In the above technical solution, the cover body 122 and the cover body 121 are provided to form the installation cavity 143 , so that the size of the air permeable channel 14 can be enlarged, and the installation of the switch component 21 is convenient.

[0145] In one embodiment of the present application, please refer to Figure 2 and Figure 22 The cover body 121 has an inner side and an outer side in the thickness direction thereof, and the cover body 122 is arranged on the inner side or the outer side.

[0146] The inner side of the cover body 121 refers to the side of the cover body 122 located in the accommodating cavity 13, and the outer side of the cover body 121 refers to the side facing away from the accommodating cavity 13 and exposed to the outside. There are many ways to set the cover body 122. The cover body 122 can be set on the inner side of the cover body 121 or on the outer side of the cover body 121, and the embodiment of the present application does not limit this. Further, the cover body 122 is set on the inner side of the cover body 121 so that the cover body 122 is hidden in the shell 1, which helps to improve the appearance of the shell 1, but this method is not convenient for keeping the accommodating cavity 13 clean. For example, welding may cause welding slag to fall into the accommodating cavity 13. The cover body 122 is set on the outer side of the cover body 121, which is convenient for connecting the cover body 121 and the cover body 122, such as welding, but this method will leave marks on the outer side of the shell 1, affecting the appearance of the shell 1.

[0147] The present application provides a battery cell 400, which includes a housing 1 and a ventilation structure 2. The housing 1 forms a receiving cavity 13 and a ventilation channel 14. The receiving cavity 13 is used to receive a bare battery cell. The ventilation channel 14 includes an air inlet 141 and an air outlet 142. The air inlet 141 communicates with the receiving cavity 13, and the air outlet 142 communicates with the external space of the housing 1. The housing 1 includes a housing body 11 and a top cover 12. The housing 1 and the top cover 12 jointly enclose the receiving cavity 13. The top cover 12 includes a cover body 122 and a cover main body 121. The cover body 122 and the cover main body 121 form an installation cavity 143. The ventilation channel 14 includes the installation cavity 143. The ventilation structure 2 includes a switching member 21 disposed in the ventilation channel 14. At least a part of the switching member 21 is movably disposed in the ventilation channel 14. In its moving stroke, the switching member 21 has a first sealing position, a second sealing position, and a ventilation position between the first sealing position and the second sealing position. In the first sealing position, the switching member 21 can seal the air inlet 141. In the second sealing position, the switching member 21 can seal the air outlet 142. In the ventilation position, the switching member 21 can open the air inlet 141 and the air outlet 142. Among them, the switching member 21 includes a sealing cylinder 211 and an outer sleeve 212. The sealing cylinder 211 is disposed along the extending direction of the ventilation channel 14. The outer sleeve 212 is tapered from one end to the other end, and has a small-diameter end 2123 and a large-diameter end 2122. The small-diameter end 2123 is sleeved on the sealing cylinder 211, and the large-diameter end 2122 is connected to the inner wall of the ventilation channel 14. Among them, under the action of the air pressure at the air inlet 141, the outer sleeve 212 can elastically deform and extend along the extending direction of the ventilation channel 14, so that the sealing cylinder 211 can move axially in the ventilation channel 14 along the outer sleeve 212 to switch between the first sealing position, the ventilation position, and the second sealing position. The small-diameter end 2123 of the outer sleeve 212 is sleeved on one end of the sealing cylinder 211 close to the air inlet 141, and the large-diameter end 2122 of the outer sleeve 212 is correspondingly located at one end of the sealing cylinder 211 close to the air outlet 142, so that the outer sleeve 212 can form a force towards the air inlet 141 to improve the sealing effect of the switching member 21.A stepped surface 144 facing away from the air inlet 141 is further formed in the air permeation channel 14. The periphery of the large-diameter end 2122 of the outer sleeve 212 is lapped on the stepped surface 144. The longitudinal section of the side wall of the outer sleeve 212 is arranged in a straight line, or in a convex curved shape, or in a concave curved shape. Different linear types are adopted for the longitudinal section of the side wall of the outer sleeve 212 so that the outer sleeve 212 can form different acting forces. The switching member 21 divides the air permeation channel 14 into a first air permeation section 145 and a second air permeation section 146. The battery cell further includes an air permeation communication part 3 communicating the first air permeation section 145 and the second air permeation section 146 to communicate both sides of the switching member 21, enabling gas to pass through the switching member 21. Among them, the air permeation communication part 3 includes a communication channel 31 provided in the housing 1. The two channel openings of the communication channel 31 communicate with the first air permeation section 145 and the second air permeation section 146 respectively. The switching member 21 includes a sealing column body 211 and an outer sleeve 212 provided on the sealing column body 211. The air permeation communication part 3 includes a communication hole 32 penetrating through the outer sleeve 212. In addition, a sealing ring 4 is provided at the air inlet 141 and / or the air outlet 142 to improve the sealing effect at the air inlet 141 or the air outlet 142. A temperature-sensitive plug 5 is provided at the air inlet 141 and / or the air outlet 142. Under normal circumstances, the air inlet 141 and / or the air outlet 142 is closed to reduce the probability of electrolyte leakage. Under high-temperature conditions, the temperature-sensitive plug 5 can be softened to open the air inlet 141 and the air outlet 142. Further, the melting point of the temperature-sensitive plug 5 is T1, and the melting point of the housing 1 is T2, where T1 < T2. The material of the temperature-sensitive plug 5 includes one of plastic or fluororubber, so that the temperature-sensitive plug 5 is easily softened by heat to open the air inlet 141 and the air outlet 142.

[0148] The present application also proposes a battery device 100. The battery device 100 includes a battery cell 400. The specific structure of the battery cell 400 refers to the above-mentioned embodiments. Since the battery device 100 adopts all the technical solutions of the above-mentioned all embodiments, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be elaborated here one by one.

[0149] The battery device 100 mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells 400 to provide higher voltage and capacity. For example, the battery device 100 mentioned in the present application may include a battery module or a battery pack, etc. The battery device 100 generally includes a box body for encapsulating one or more battery cells 400. The box body can prevent liquid or other foreign matters from affecting the charging or discharging of the battery cell 400.

[0150] The present application also provides an electrical device, which includes a battery device 100. For the specific structure of this electrical device, please refer to the above embodiments. Since this electrical device adopts all the technical solutions of the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be elaborated herein one by one.

[0151] The battery device 100 disclosed in the embodiments of the present application can be used to provide electrical energy for an electrical device. Among them, the electrical device can be, but is not limited to, a battery car, an electric vehicle, a ship, a spacecraft, etc. Among them, the spacecraft can include an airplane, a rocket, a space shuttle, a spaceship, etc.

[0152] For the convenience of description in the following embodiments, a vehicle 1000, which is an electrical device in an embodiment of the present application, is taken as an example for illustration.

[0153] Please refer to Figure 23 , Figure 23 which is a schematic structural diagram of an embodiment in which the electrical device provided by the present application is a vehicle. The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. The battery device 100 is disposed inside the vehicle 1000, and the battery device 100 can be disposed at the bottom, the head or the tail of the vehicle 1000. The battery device 100 can be used for power supply of the vehicle 1000. For example, the battery device 100 can be used as the operating power source of the vehicle 1000. The vehicle 1000 may further 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, it is used for the working power requirements during the start, navigation and driving of the vehicle 1000.

[0154] In some embodiments of the present application, the battery device 100 can not only be used as the operating power source of the vehicle 1000, but also be used as the driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0155] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be covered by the scope of the claims and the description of the present application. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way. The present 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: A shell is formed with a containing cavity and a vent passage connected to the containing cavity, the vent passage includes an air inlet and an air outlet, the air inlet is connected to the containing cavity, the air outlet is used to connect to the external space, and the shell is provided with a pole and an explosion-proof valve; as well as, The ventilation structure comprises a switch member arranged in the ventilation channel, wherein at least a part of the switch member can be movably arranged in the ventilation channel, and in its movable stroke, the switch member has a first sealing position, a second sealing position and a ventilation position between the first sealing position and the second sealing position, when in the first sealing position, the switch member can seal the air inlet, when in the second sealing position, the switch member can seal the air outlet, and when in the ventilation position, the switch member can open the air inlet and the air outlet; When the switch element is in the first sealing position, the pressure inside the shell is P1, when the switch element is in the ventilating position, the pressure inside the shell is P2, and when the switch element is in the second sealing position, the pressure inside the shell is P3, wherein P1<P2<P3.

2. The battery cell according to claim 1, characterized in that: The switch element comprises: A sealing column is arranged along the extension direction of the air permeable channel; and The outer casing is tapered from one end to the other end to have a small diameter end and a large diameter end, the small diameter end is sleeved on the sealing column, and the large diameter end is connected to the inner wall of the air permeable channel; Wherein, under the action of the air pressure of the air inlet, the outer shell can be elastically deformed along the extension direction of the air permeable channel, so that the sealing column can move axially along the outer shell in the air permeable channel to switch between the first sealing position, the air permeable position and the second sealing position.

3. The battery cell according to claim 2, characterized in that: The small diameter end is sleeved on one end of the sealing cylinder close to the air inlet; The large diameter end corresponds to an end of the sealing cylinder close to the air outlet.

4. The battery cell according to claim 3, characterized in that: A step surface facing away from the air inlet is formed in the air permeable passage, and the periphery of the large diameter end overlaps the step surface.

5. The battery cell according to claim 2, characterized in that: The longitudinal section of the side wall of the outer casing is arranged in a straight line; or, The longitudinal section of the side wall of the outer casing is arranged in an outwardly convex curved shape; or, The longitudinal section of the side wall of the outer casing is arranged in a concave curved shape.

6. The battery cell according to claim 1, characterized in that: The switch element divides the air permeable channel into a first air permeable section and a second air permeable section; The battery cell further includes a ventilation connecting portion connecting the first ventilation section and the second ventilation section.

7. The battery cell according to claim 6, characterized in that: The air-permeable communication portion includes a communication channel provided on the shell, and two channel openings of the communication channel are respectively connected to the first air-permeable section and the second air-permeable section.

8. The battery cell according to claim 6, characterized in that: The switch element comprises a sealing cylinder and an outer sleeve provided on the sealing cylinder; The air-permeable communication portion includes a communication hole extending through the outer shell.

9. The battery cell according to claim 1, characterized in that: A sealing ring is arranged at the air inlet and / or the air outlet.

10. The battery cell according to claim 1, characterized in that: A temperature-sensitive plug is provided at the air inlet and / or the air outlet.

11. The battery cell according to claim 10, characterized in that: The melting point of the temperature-sensitive plug is T1, and the melting point of the shell is T2, wherein T1<T2; and / or, The material of the temperature sensitive plug includes one of plastic and fluororubber.

12. The battery cell according to claim 11, characterized in that: T1≤400℃。 13. The battery cell according to claim 1, characterized in that: The shell comprises a shell body and a top cover disposed on the shell body, wherein the shell body and the top cover together form the accommodating cavity; Wherein, the air permeable channel and the pole are both arranged on the top cover.

14. The battery cell according to claim 13, characterized in that: The top cover comprises a cover body and a cover body disposed on the cover body, the cover body and the cover body together form an installation cavity, and the switch element is installed in the installation cavity; Wherein, the air permeable channel includes the installation cavity.

15. A battery device, characterized in that: Comprising a battery cell as claimed in any one of claims 1 to 14.

16. An electrical equipment, characterized in that: Comprising the battery device as claimed in claim 15.

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