Battery cell, battery, and electric device

Abstract

The present application discloses a battery cell, a battery, and an electric device. The battery cell comprises a casing and a one-way valve; the casing is provided with a wall portion; the one-way valve comprises a valve body and a valve core; the valve body is arranged on the outer surface of the wall portion, and at least part of the valve body protrudes out of the outer surface of the wall portion; a valve cavity is formed inside the valve body, and the valve core is arranged in the valve cavity; and the valve core is used for plugging a gas inlet of the valve cavity, and the valve core is configured to open the gas inlet under the action of gas inside the casing and release the gas inside the battery cell. By means of such an arrangement, the gas inside the casing can be discharged out of the casing in a timely manner, so that the gas pressure inside the casing is not excessively high, thereby reducing the risk that a pressure relief mechanism opens the valve in advance, and greatly prolonging the service life of the battery cell.

Description

Battery cells, batteries and electrical equipment Technical Field

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

[0002] As global energy and environmental problems continue to intensify, new energy, as one of the areas of sustainable development, is developing rapidly. Batteries are being used more and more widely as a new energy source, and there are high requirements for their reliability and service life. During the charging and discharging process of the battery, the internal pressure of the battery will increase due to the generation of gas inside the battery. In order to ensure the safety of the battery cell, a pressure relief mechanism for releasing the internal pressure of the battery cell is generally provided on the outer shell of the battery cell, so that when the internal pressure or temperature of the battery cell reaches a threshold, the pressure relief mechanism can be actuated and release the pressure inside the battery cell. However, the pressure relief mechanism of the existing battery cell may actuate and release the pressure in advance during use, resulting in poor stability of the battery cell, which is not conducive to improving the service life and reliability of the battery cell. The above statements are only used to provide background technical information related to this application and do not necessarily constitute prior art.

[0003] Summary of the Invention

[0004] The main technical problem solved by the present application is to provide a battery cell, a battery and an electrical device that can discharge the gas inside the battery casing to the outside of the casing in time, so that the air pressure inside the battery casing will not be too high, and the risk of the pressure relief mechanism opening the valve prematurely is reduced, which can greatly improve the battery life.

[0005] To solve the above technical problems, the present application adopts a technical solution: providing a battery cell, the battery cell comprising a housing and a one-way valve, the housing having a wall portion, the wall portion having a first vent, the first vent communicating with the interior of the housing; the one-way valve comprising a valve body and a valve core, the valve body having a valve cavity, the valve body being provided with an air inlet and an air outlet, the air inlet communicating with the valve cavity and the interior of the housing, and the air outlet communicating with the valve cavity and the exterior of the housing; the valve core being disposed in the valve cavity, the valve core being used to block the air inlet, and the valve core being configured to open the air inlet under the action of gas inside the housing and release gas inside the battery cell; the wall portion having an outer surface and an inner surface disposed opposite to each other, the outer surface being disposed toward the exterior of the housing, and the inner surface being disposed toward the interior of the housing; the valve body being disposed on the outer surface, with at least a portion of the valve body protruding from the outer surface. Through this arrangement, gas inside the battery housing can be promptly discharged outside the housing, preventing the air pressure inside the battery housing from being excessively high.

[0006] In one embodiment, the valve body includes a valve seat and a valve cover. The valve cover includes a cover top wall and a cover side wall connected to the cover top wall. The cover top wall, the cover side wall, and the valve seat enclose a valve cavity. The valve seat is provided with an air inlet for the valve cavity, and the valve cover is provided with an air outlet for the valve cavity. This facilitates the discharge of gas.

[0007] In one embodiment, the valve seat has a first through hole penetrating the valve seat, and the air inlet is the first through hole. In this way, the discharge of gas is facilitated.

[0008] In one embodiment, the cover sidewall has a second through hole penetrating the cover sidewall, and the gas outlet is the second through hole. In this way, the gas is easily discharged.

[0009] In one embodiment, the second through hole extends to the end of the cover side wall in a direction away from the cover top wall; in this way, the discharge of gas is facilitated.

[0010] In one embodiment, there are multiple second through holes, and the multiple second through holes are spaced apart in the circumferential direction of the side wall, thereby facilitating the discharge of gas.

[0011] In one embodiment, a first guide post is protruding from the side of the lid top wall facing the valve seat, and a third through hole is formed on the lid top wall, penetrating the lid top wall and the first guide post, or the lid top wall has a third through hole penetrating the lid top wall, and the gas outlet is the third through hole. In this manner, gas discharge is facilitated.

[0012] In one embodiment, the valve cover further comprises a flange wall, the cover side wall connects the cover top wall and the flange wall, the flange wall extends relative to the cover side wall toward a side away from the valve cavity, and the flange wall is connected to the valve seat. In this way, the assembly of the one-way valve is facilitated.

[0013] In one embodiment, a first recessed groove is provided on the side of the valve seat facing the valve cover, which is recessed relative to the surface of the valve seat. At least a portion of the flange wall is accommodated in the first recessed groove and connected to the valve seat. In this way, the installation height of the one-way valve can be reduced.

[0014] In one embodiment, a first step surface and a second step surface are provided on a side of the valve seat facing the valve cover, the first step surface being closer to the valve cover than the second step surface, and the first recess being provided on the first step surface. In this manner, assembly stability can be improved.

[0015] In one embodiment, the surface of the flange facing the top wall of the cover is flush with the surface of the valve seat facing the valve cover; or the surface of the flange facing the top wall of the cover is lower than the surface of the valve seat facing the valve cover. In this way, the connection strength can be improved while reducing the installation height of the one-way valve.

[0016] In one embodiment, the flange wall is welded to the valve seat; wherein, along the circumference of the cover sidewall, at least a portion of the first weld mark between the flange wall and the valve seat is offset from the second through hole in the cover sidewall. This reduces damage to the valve core component caused by high temperatures during the welding process.

[0017] In one embodiment, a connecting protrusion is provided on the outer circumference of the valve seat, and a receiving groove is provided on the inner circumference of the flange wall. The connecting protrusion is received in the receiving groove and connected to the flange wall. In this way, the connection strength can be improved while reducing the installation height of the one-way valve.

[0018] In one embodiment, the connecting protrusion is welded to the flange wall, wherein the flange wall has an upper surface and a lower surface disposed opposite each other, with the upper surface facing the top wall of the cover, and a second weld mark formed by welding the connecting protrusion to the flange wall is located on the lower surface of the flange wall. This method can reduce damage to the valve core component caused by high temperatures during the welding process.

[0019] In one embodiment, the valve body includes a valve cover, which includes a cover top wall and a cover side wall connected to the cover top wall. The cover top wall, the cover side wall, and the wall portion enclose a valve cavity. The wall portion is provided with an air inlet for the valve cavity, and the cover side wall is provided with an air outlet for the valve cavity. In this manner, the discharge of gas is facilitated.

[0020] In one embodiment, a second recessed groove is provided on a side of the wall portion facing the exterior of the housing, the recessed groove being recessed relative to the outer surface of the wall portion. The valve cover further comprises a flanged wall. The cover side wall connects the cover top wall and the flanged wall. The flanged wall extends relative to the cover side wall toward a side away from the valve cavity. At least a portion of the flanged wall is accommodated in the second recessed groove and connected to the wall portion. In this manner, the installation height of the one-way valve can be reduced.

[0021] In one embodiment, the valve core includes an elastic member and a blocking member. The elastic member is disposed within the valve cavity. The blocking member is movably disposed within the valve cavity. The blocking member is used to block the air inlet passage under the action of the elastic member and to open the air inlet passage under the action of gas within the housing. In this manner, gas discharge can be facilitated.

[0022] In one embodiment, the valve body includes a valve cover and a valve seat, which form a valve cavity. A first guide column is protruding from the side of the valve cover facing the sealing member, and part of the elastic member is sleeved on the outside of the first guide column; in this way, the positioning and guiding of the elastic member can be achieved.

[0023] In one embodiment, the diameter of the first guide post is D1, and the inner diameter of the elastic member is D2, which satisfies the following relationship: 0mm<D2-D1≤5mm. In this way, the assembly of the elastic member and the first guide post can be facilitated.

[0024] In one embodiment, a second guide post is protruded from the side of the blocking member facing the valve cover, and a portion of the elastic member is sleeved on the outer side of the second guide post. In this way, the elastic member can be positioned and guided.

[0025] In one embodiment, the diameter of the second guide post is D3, and the inner diameter of the elastic member is D2, which satisfies the following relationship: 0mm<D3-D1≤5mm. In this way, the assembly of the elastic member and the second guide post can be facilitated.

[0026] In one embodiment, in the axial direction of the elastic member, a gap is formed between an end surface of the first guide post away from the valve cover and an end surface of the second guide post closer to the valve cover; a height H1 of the gap satisfies 0 mm < H1 ≤ 0.5 mm. This improves space utilization.

[0027] In one embodiment, in the axial direction of the valve cavity, the ends of the elastic member respectively abut the valve cover and the blocking member. The distance between the first abutting surface of the valve cover and the second abutting surface of the blocking member is L1, and the physical length of the elastic member is L2, satisfying the condition L1>L2. The physical length of the elastic member is the physical length of the elastic member when fully compressed; optionally, L1-L2>0.5mm. In this manner, space is reserved for the elastic member to compress, thereby driving the blocking member to block / open the air inlet passage.

[0028] In one embodiment, the elastic member is a spring, and the physical length L2 of the elastic member is L2 = d1*n1+d2+d3, where d1 is the spring wire diameter, n1 is the maximum number of turns of the spring in the axial direction, d2 is the thickness of the outermost spring at one end of the spring, and d3 is the thickness of the outermost spring at the other end of the spring, d2≤d1, d3≤d1.

[0029] In one embodiment, the outer circumferential surface of the blocking member is provided with a plurality of limiting protrusions, which are arranged at intervals along the circumference of the blocking member. In this way, the blocking member can be guided and limited, thereby improving the stability of the blocking member's movement.

[0030] In one embodiment, the sealing member includes a pressing portion and a sealing portion. Along the thickness of the wall, the ends of the elastic member abut against the valve cover and the pressing portion, respectively. The sealing portion is connected to the side of the pressing portion facing away from the valve cover and is used to seal the air inlet passage. This helps maintain the tightness of the housing.

[0031] In one embodiment, the sealing portion is made of EPDM, fluororubber or Teflon.

[0032] In one embodiment, the elastic member is made of steel, iron or aluminum.

[0033] In one embodiment, the valve cover includes a sidewall having a second through-hole extending therethrough. The gas outlet is the second through-hole. Along the axis of the valve cavity, the sealing interface between the valve core and the valve seat is higher than or flush with the bottom wall of the second through-hole. This facilitates gas discharge.

[0034] In one embodiment, the wall portion is provided with a first exhaust hole, and the one-way valve is at least partially accommodated in the first exhaust hole.

[0035] In one embodiment, the first vent includes a through-hole segment and a first hole segment, which are arranged along the thickness of the wall. The through-hole segment connects the interior of the housing with the exterior of the housing. The first hole segment is located on the side of the through-hole segment facing away from the interior of the housing. The aperture of the first hole segment is larger than the aperture of the through-hole segment. The one-way valve is at least partially accommodated in the first hole segment. The valve body of the one-way valve faces the exterior of the housing, and at least a portion of the valve body protrudes from the outer surface of the wall. This facilitates assembly of the one-way valve.

[0036] In one embodiment, the first hole section includes a circumferentially arranged hole side surface, and the outer circumferential surface of the valve cover / valve seat of the one-way valve is welded to the hole side surface, thereby improving the connection strength.

[0037] In one embodiment, the valve seat is provided with a first step surface and a second step surface on a side facing the valve cover, the first step surface being closer to the valve cover than the second step surface, and the outer peripheral surface of the second step surface being welded to the side surface of the hole. In this way, assembly stability can be improved.

[0038] In one embodiment, the hole side surface is aligned with the outer circumference of the valve cover / valve seat of the one-way valve, and both the hole side wall surface and the outer circumference of the valve cover / valve seat of the one-way valve are arranged at an acute angle to the central axis of the first exhaust hole, thereby improving the connection strength.

[0039] In one embodiment, a stress relief groove is provided around the weld mark between the valve cover / valve seat and the wall portion. Optionally, a first stress relief groove is provided on the surface of the valve seat / valve cover facing the exterior of the housing; and / or a second stress relief groove is provided on the surface of the wall portion facing the exterior of the housing. In this manner, the stability of the connection can be improved.

[0040] In one embodiment, the valve body is provided with a weak area, so that when the pressure inside the battery cell is too high, the valve body can be broken at the weak area, thereby achieving the effect of quickly discharging the gas inside the battery cell.

[0041] In one embodiment, the strength weak area includes a thickness weak area. This arrangement is helpful in simplifying the manufacturing process.

[0042] In one embodiment, the valve body includes a valve cover, the valve cover including a cover top wall and a cover side wall connected to the cover top wall, and the thickness weakened area includes a groove provided on the cover side wall. This arrangement can reduce damage to the battery housing caused by valve body fracture.

[0043] In one embodiment, the cover sidewall has a second through hole penetrating the cover sidewall, and the groove is provided on the connecting arm between two adjacent second through holes. This arrangement is conducive to simplifying the manufacturing process.

[0044] In one embodiment, the groove is located on the side of the cover sidewall facing the valve cavity; or the groove is located on the side of the cover sidewall away from the valve cavity. This arrangement is conducive to simplifying the manufacturing process.

[0045] In one embodiment, the thickness weakened area includes a first notch groove, which is a circumferential groove on the side wall of the cover. This arrangement can accelerate the rupture of the valve body when the internal pressure of the battery cell is excessive, thereby achieving the effect of quickly discharging the gas inside the battery cell.

[0046] In one embodiment, the thickness weakened area includes a plurality of second scoring grooves, and the plurality of second scoring grooves are spaced apart in the circumferential direction of the cover side wall. This arrangement is conducive to simplifying the manufacturing process.

[0047] In one embodiment, the battery cell further includes an insulating member disposed on a side of the wall portion facing the interior of the housing; the insulating member is provided with a second vent hole penetrating the insulating member, the second vent hole being connected to the first vent hole on the wall portion. In this manner, the gas can be easily discharged.

[0048] In one embodiment, a first vent is provided on the wall, and at least a portion of the one-way valve is installed within the first vent. The first vent serves as the liquid injection hole for the battery cell. Alternatively, the first vent is spaced apart from the liquid injection hole. In this way, replacing the original sealing structure of the liquid injection hole with a one-way valve can facilitate the configuration of the battery cell.

[0049] In one embodiment, the housing includes a shell and an end cap. The shell defines an opening within the housing for accommodating the electrode assembly. The end cap seals the opening. The end cap is a wall, or the shell includes a wall, or the wall is located at the top of the housing when the battery cell is in a placed state. This facilitates gas discharge.

[0050] In one embodiment, the battery cell further includes a pressure relief mechanism disposed on the outer casing. The pressure relief mechanism is configured to activate and release the internal pressure of the battery cell in the event of thermal runaway. The actuation pressure of the pressure relief mechanism is greater than the opening pressure of the one-way valve. In this way, the safety of the battery can be improved.

[0051] In one embodiment, the wall portion has a pressure relief hole that connects the interior of the housing with the exterior of the housing and is connected to the pressure relief mechanism. The diameter of the pressure relief hole is larger than the diameter of the first vent hole. In this way, the pressure relief capacity of the battery cell is improved.

[0052] In one embodiment, the exhaust rate of the one-way valve is lower than the exhaust rate of the pressure relief mechanism, thereby improving the pressure relief capability of the battery cell.

[0053] In one embodiment, the opening pressure of the one-way valve is greater than or equal to 0.2 MPa; optionally, greater than or equal to 0.4 MPa, which is beneficial for regulating the internal pressure of the battery cell.

[0054] In one embodiment, the valve body is provided with a weak zone, the actuation pressure of the pressure relief mechanism is greater than the actuation pressure of the weak zone, and the actuation pressure of the weak zone is greater than the opening pressure of the one-way valve. In this way, the pressure relief capability of the battery cell is improved.

[0055] In one embodiment, the diameter of the air inlet is greater than or equal to the diameter of the first exhaust hole. In this way, the pressure relief capability of the battery cell is improved.

[0056] To solve the above technical problems, another technical solution adopted by the present application is to provide a battery comprising the above battery cells, which has at least the same advantages as the battery cells.

[0057] To solve the above technical problems, another technical solution adopted by the present application is to provide an electrical device comprising the above battery, which has at least the same advantages as the battery.

[0058] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0060] FIG1 is a schematic diagram of an exploded structure of a battery cell according to one or more embodiments;

[0061] FIG2 is a schematic cross-sectional view of a one-way valve according to one or more embodiments;

[0062] FIG3a is a schematic structural diagram of a blocking member of a one-way valve according to one or more embodiments;

[0063] FIG3 b is a schematic cross-sectional view of a one-way valve according to one or more embodiments;

[0064] FIG3c is a schematic diagram of a state of an elastic member according to one or more embodiments;

[0065] FIG4 is a schematic diagram of an exploded structure of a one-way valve according to one or more embodiments;

[0066] FIG5 is a front view of a one-way valve according to one or more embodiments;

[0067] FIG6 is a schematic diagram of a partial cross-sectional structure of a battery cell according to one or more embodiments;

[0068] FIG7 is a schematic cross-sectional view of a one-way valve according to one or more embodiments;

[0069] FIG8 is a front view of a one-way valve according to one or more embodiments;

[0070] 9 is a bottom view of a one-way valve according to one or more embodiments;

[0071] FIG10 is a schematic diagram of an exploded structure of a one-way valve according to one or more embodiments;

[0072] FIG11 is a schematic diagram of a partial cross-sectional structure of a battery cell according to one or more embodiments;

[0073] FIG12 is a schematic diagram of a partial cross-sectional structure of a battery cell according to one or more embodiments;

[0074] FIG13 is a schematic diagram of a partial cross-sectional structure of an end cap according to one or more embodiments;

[0075] FIG14 is a front view of an end cap of a battery cell according to one or more embodiments;

[0076] FIG15 is a schematic diagram of a partially exploded structure of a battery cell according to one or more embodiments;

[0077] FIG16 is a front view of a one-way valve according to one or more embodiments;

[0078] FIG17 is a schematic diagram of an exploded structure of a one-way valve according to one or more embodiments;

[0079] FIG18 is a schematic cross-sectional view of a one-way valve according to one or more embodiments;

[0080] FIG19 is a schematic diagram of a one-way valve according to one or more embodiments;

[0081] FIG20 is a front view of an end cap of a battery cell according to one or more embodiments;

[0082] FIG21 is a schematic diagram of a partially exploded structure of a battery cell according to one or more embodiments;

[0083] FIG22 is a schematic diagram of an exploded structure of a battery cell according to one or more embodiments;

[0084] FIG23 is a schematic diagram of an exploded structure of a battery according to one or more embodiments;

[0085] FIG24 is a schematic structural diagram of a vehicle according to one or more embodiments.

[0086] In the accompanying drawings: 1000, vehicle; 300, motor; 200, controller; 100, battery; 10, housing; 11, first part; 12, second part; 20, battery cell; 21, end cap; 21a, outer surface; 21b, inner surface; 291, first vent hole; 22, housing; 23, electrode assembly; 24, insulating member; 292, second vent hole; 25, electrode terminal; 280, through-hole section; 281, first hole section; 30, one-way valve; 31, valve body; 311, valve seat; 3111, first through-hole; 3112, first sink; 3113, connecting protrusion; 3119, weak area; 312, valve cover; 3121, cover top wall; 31211, first guide column; 31212, third through-hole; 3122, cover Side wall; 3122a, solid area; 3122b, exhaust area; 31221, second through hole; 31222, flange wall; 31222a, connecting surface; 31222b, accommodating groove; 31222c, upper surface; 31222d, lower surface; 313, valve cavity; 313a, air inlet; 313b, air outlet; 32, valve core; 321, blocking part; 3211, sealing part; 3212, pressing part; 3212a, limiting protrusion; 3212b, second guide column; 322, elastic part; 60, protective patch; 601, first avoidance hole; 602, second avoidance hole; 603, third avoidance hole; 70, pressure relief mechanism; 701, pressure relief hole; W1, first weld mark; W2, second weld mark; W3, third weld mark. DETAILED DESCRIPTION

[0087] In order to make the purpose, technical solution and effect of this application clearer and more specific, the following embodiments of the technical solution of this application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of this application and are therefore only examples and are not intended to limit the scope of protection of this application.

[0088] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art 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 specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0089] In the description of the embodiments of the present application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two), similarly, "multiple groups" refers to more than two (including two), and "multiple pieces" refers to more than two (including two), unless otherwise clearly and specifically defined.

[0090] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0091] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0092] Amounts, ratios, and other numerical values ​​are presented herein in a range format. It should be understood that such range format is used for convenience and brevity and should be interpreted flexibly to include not only the values ​​explicitly specified as range limits, but also all individual values ​​or sub-ranges encompassed within the range, as if each value and sub-range were explicitly specified.

[0093] In the description of the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and do not constitute any limitation on this application.

[0094] 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., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and 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 device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0095] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0096] Batteries have a wide range of applications in the new energy sector, primarily in electric vehicles, energy storage systems, and renewable energy. In the electric vehicle sector, higher performance features such as longer driving range and faster charging are gradually being achieved. In energy storage systems, batteries are widely used for large-scale and distributed energy storage. They can balance grid loads, store renewable energy such as solar and wind power, and release the stored energy during peak periods. Furthermore, small rechargeable batteries are widely used in applications such as wearable devices, drones, and smart homes.

[0097] As the battery charges and discharges, some side reactions generate gases. If these gases are not promptly discharged, the internal pressure of the battery will increase. Excessive internal pressure can negatively impact the battery's performance and appearance. For example, in severe cases, this can have devastating effects on the battery's performance and appearance, such as leakage, bulging, increased internal resistance, and shortened discharge time and cycle life. Furthermore, batteries can be subject to abnormal operation during use, including overcharging, over-discharging, and internal failures. In these cases, the chemical reactions within the battery may become uncontrolled, accompanied by a violent release of gas, and even trigger thermal runaway. Battery thermal runaway refers to a chain reaction phenomenon triggered by various factors. The large amount of heat and harmful gases emitted by thermal runaway can cause the battery to catch fire and explode.

[0098] To improve the safety of battery cells, a pressure relief mechanism is typically installed on the outer casing of the battery cell to release the internal pressure of the battery cell, thereby effectively improving the safety of the battery cell. However, during the use of the battery cell, unstable internal pressure may cause the pressure relief mechanism of the battery cell to activate prematurely, resulting in poor stability in the use of the battery cell, which is not conducive to improving the service life and reliability of the battery cell.

[0099] Based on the above considerations, an embodiment of the present application provides a battery cell, on which a one-way valve is provided. The one-way valve can be used to discharge the gas inside the battery cell in a timely manner to maintain a stable internal pressure of the battery cell.

[0100] Please refer to Figure 1, which is a schematic diagram of the exploded structure of a battery cell 20 according to one or more embodiments. A battery cell 20 is the smallest unit that makes up a battery 100. As shown in Figure 1, a battery cell 20 includes an end cap 21, a housing 22, an electrode assembly 23, and other functional components.

[0101] The end cap 21 refers to a component that covers the opening of the housing 22 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 21 can be adapted to the shape of the housing 22 to match the housing 22. Optionally, the end cap 21 can be made of a material with a certain hardness and strength (such as an aluminum alloy). In this way, the end cap 21 is less likely to deform when squeezed or collided, so that the battery cell 20 can have a higher structural strength and improved safety performance. Functional components such as electrode terminals 25 can be provided on the end cap 21. The electrode terminals 25 can be used to electrically connect to the electrode assembly 23 to output or input electrical energy from the battery cell 20. Exemplarily, the battery cell 20 is provided with two electrode terminals 25, and both electrode terminals 25 are mounted on the end cap 21. The two electrode terminals 25 are respectively used to electrically connect to the two tabs of opposite polarity of the electrode assembly 23 to respectively output or input the positive and negative electrodes of the battery cell 20. In some embodiments, the end cap 21 may also be provided with a pressure relief mechanism 70 for releasing the internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold value. The material of the end cap 21 may also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not impose any special restrictions on this. In some embodiments, an insulating member 24 may also be provided on the inner side of the end cap 21. The insulating member 24 may be used to isolate the electrical connection components in the housing 22 from the end cap 21 to reduce the risk of short circuit. Exemplarily, the insulating member 24 may be plastic, rubber, etc.

[0102] The housing 22 is a component that cooperates with the end cap 21 to form the internal environment of the battery cell 20. This internal environment can be used to accommodate the electrode assembly 23, electrolyte, and other components. The housing 22 and end cap 21 can be separate components. An opening can be provided in the housing 22, and the end cap 21 is placed over the opening to form the internal environment of the battery cell 20. Alternatively, the end cap 21 and housing 22 can be integrated. Specifically, the end cap 21 and housing 22 can form a common connection surface 31222a before other components are inserted into the housing. When the interior of the housing 22 is to be enclosed, the end cap 21 is placed over the housing 22. The housing 22 can have a variety of shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, or a hexagonal prism. Specifically, the shape of the housing 22 can be determined based on the specific shape and size of the electrode assembly 23. The housing 22 can be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this embodiment of the present application does not impose any particular limitations on this.

[0103] The electrode assembly 23 is a component in the battery cell 20 where electrochemical reactions occur. One or more electrode assemblies 23 may be contained in the housing 22. The electrode assembly 23 is mainly formed by winding or stacking positive and negative electrode sheets, and a separator is usually provided between the positive and negative electrode sheets. The parts of the positive and negative electrode sheets with active materials constitute the main body of the electrode assembly 23, and the parts of the positive and negative electrode sheets without active materials each constitute a tab. The positive and negative electrode tabs may be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery 100, the positive electrode active material and the negative electrode active material react with the electrolyte, and the tabs are connected to the electrode terminals 25 to form a current loop.

[0104] Please refer to Figure 14, which is a schematic diagram of a partially exploded structure of a battery cell 20 according to one or more embodiments. According to some embodiments of the present application, the present application discloses a battery cell 20, which includes a housing and a one-way valve 30. The housing has a wall portion, and the one-way valve 30 is disposed on the wall portion. The one-way valve 30 is used to exhaust gas inside the housing.

[0105] In the battery cell 20 of this structure, a one-way valve 30 is provided on the wall of the outer shell so that the one-way valve 30 can discharge the gas inside the outer shell to the outside of the outer shell, so that when gas is generated inside the outer shell during normal use of the battery cell 20, it can be discharged to the outside of the outer shell through the one-way valve 30, so as to alleviate the phenomenon that the internal pressure of the battery cell 20 reaches the threshold value in advance due to the increase in the internal air pressure of the battery cell 20, thereby causing the battery cell 20 to be actuated and depressurized in advance, thereby effectively improving the use stability of the battery cell 20, thereby improving the service life and reliability of the battery cell 20.

[0106] According to some embodiments of the present application, the outer shell includes an end cover 21 and a shell 22, and the wall portion may be the wall of the end cover 21 or the wall of the shell 22. That is, the one-way valve 30 may be arranged on the end cover 21 or on the shell 22. In other words, the wall portion for installing the one-way valve 30 may be the end cover 21 of the outer shell or a wall of the shell 22 of the outer shell. Exemplarily, the wall portion is the end cover 21. Of course, the structure of the battery cell 20 is not limited to this. In other embodiments, the wall portion may also be the bottom wall of the shell 22 and the end cover 21, and the wall portion may also be the side wall of the shell 22 and the end cover 21 adjacent to and connected to each other. The following will take the wall portion as the wall of the end cover 21 as an example to illustrate the present application scheme, but this should not limit the present application.

[0107] According to some embodiments of the present application, the one-way valve 30 is configured to actuate and release the gas inside the battery cell 20 when the internal gas pressure of the battery cell 20 reaches a threshold value. In other words, the one-way valve 30 is used to exhaust the gas inside the housing. That is, the one-way valve 30 can be opened in one direction to exhaust gas, so that the gas inside the housing can be discharged to the outside of the housing through the one-way valve 30.

[0108] Please refer to Figure 2, which is a schematic cross-sectional view of a one-way valve 30 according to one or more embodiments. According to some embodiments of the present application, the one-way valve 30 includes a valve body 31 and a valve core 32. The valve body 31 has a valve cavity 313 therein. The valve body 31 is provided with an air inlet 313a and an air outlet 313b. The air inlet 313a connects the valve cavity 313 with the interior of the housing, and the air outlet 313b connects the valve cavity 313 with the exterior of the housing. The valve core 32 is disposed within the valve cavity 313 and is used to block the air inlet 313a of the valve cavity 313. The valve core 32 is configured to open the air inlet 313a under the action of the gas inside the housing and release the gas inside the battery cell 20.

[0109] Among them, the air inlet 313a is used to connect the valve cavity 313 and the interior of the shell, that is, the gas inside the shell can enter the valve cavity 313 through the air inlet 313a; the air outlet 313b is used to connect the valve cavity 313 and the outside of the shell, that is, the gas in the valve cavity 313 can be discharged to the outside of the shell through the air outlet 313b; through this arrangement, the gas inside the shell of the battery cell 20 can be discharged to the outside of the shell through the valve cavity 313.

[0110] Specifically, when the gas inside the battery cell 20 casing is exhausted through the one-way valve 30, its exhaust path is from the inside of the battery cell 20 - air inlet 313a - valve cavity 313 - air outlet 313b - outside the battery cell 20. This entire exhaust path constitutes the exhaust channel; as shown in Figure 2(b), the path from A to B, A represents the inside of the casing, and B represents the outside of the casing. In other words, the gas inside the battery cell 20 casing enters the valve cavity 313 from the air inlet 313a, flows through the valve cavity 313, and is exhausted from the air outlet 313b of the valve cavity 313 to the outside of the battery 100 casing.

[0111] Furthermore, the valve core 32 is used to block the air inlet channel of the valve cavity 313, and is used to open the air inlet channel under the action of the gas inside the shell. The air inlet channel is the channel through which the gas inside the shell enters the valve cavity 313 and flows after entering the valve cavity 313, or the air inlet channel can be a part of the exhaust channel, more specifically, the partial path before the air outlet 313b of the exhaust channel. The valve core 32 blocks the air inlet channel, which means that the gas is not allowed to enter the valve cavity 313, or the gas is allowed to enter the valve cavity 313 but the gas is not allowed to flow out of the valve cavity 313. The valve core 32 can directly block the air inlet 313a and not allow the gas to enter the valve cavity 313; or it can block the flow path of the gas, that is, the gas can enter the valve cavity 313 through the air inlet 313a, but its flow path is blocked and cannot continue to flow to the air outlet 313b. When the valve core 32 blocks the air inlet passage, gas outside the housing cannot enter the interior of the housing, and gas inside the housing cannot be discharged outside the housing. When the pressure of the gas inside the housing reaches a certain threshold, the gas inside the housing can push the valve core 32 to open the air inlet passage, allowing the gas inside the housing to enter the valve cavity 313 and then be discharged outside the housing through the air outlet 313b. At the same time, the valve core 32 can only be opened in one direction by applying pressure from the interior of the housing, allowing gas to flow out, and cannot be reversed from the exterior of the housing.

[0112] Alternatively, the valve core 32 may have various structures. For example, in FIG2 , the valve core 32 may include an elastic member 322 and a blocking member 321. Both the elastic member 322 and the blocking member 321 are disposed within the valve cavity 313. The elastic member 322 is configured to provide elastic force to the blocking member 321. The sealing and opening of the valve cavity 313 are achieved through deformation of the elastic member 322. Specifically, the elastic member 322 is disposed within the valve cavity 313, and the blocking member 321 is movably disposed within the valve cavity 313. The blocking member 321 is configured to block the air inlet passage under the action of the elastic member 322, and to open the air inlet 313a under the action of the gas inside the housing.

[0113] Among them, the blocking member 321 is movably arranged in the valve cavity 313, that is, the blocking member 321 can move in the valve cavity 313, so that the blocking member 321 can block the air inlet 313a when it moves close to the air inlet 313a, and conversely, when the blocking member 321 moves away from the air inlet 313a, it can open the air inlet 313a.

[0114] In some embodiments, the blocking member 321 is loosely fitted with the inner wall of the valve cavity 313 .

[0115] Illustratively, the air inlet 313a extends through the bottom surface of the valve cavity 313, and accordingly, the blocking member 321 is movably disposed within the valve cavity 313 along the axial direction of the valve cavity 313 (direction Y in the figure), such that the blocking member 321 can block the air inlet 313a when abutting against the bottom surface of the valve cavity 313. Of course, in other embodiments, the air inlet 313a may also be disposed on a radial side of the valve body 31, and accordingly, the blocking member 321 is movably disposed within the valve cavity 313 along the radial direction of the valve body 31.

[0116] The sealing member 321 is used to seal the air inlet 313a under the action of the elastic member 322, and is used to open the air inlet 313a under the action of the gas inside the shell. That is to say, the elastic member 322 can provide elastic force for the sealing member 321, so that the sealing member 321 can abut against the bottom surface of the valve cavity 313 to seal the air inlet 313a. Conversely, when the force of the gas inside the shell acting on the sealing member 321 is greater than the elastic force of the elastic member 322, the gas inside the shell can overcome the elastic force of the elastic member 322 and push the sealing member 321 to separate from the bottom surface of the valve cavity 313, so that the sealing member 321 opens the air inlet 313a, thereby allowing the gas inside the shell to enter the valve cavity 313 through the air inlet 313a and then be discharged through the air outlet 313b.

[0117] As shown in Figure 2, Figure 2 (a) is a schematic diagram of the one-way valve 30 in the closed state; Figure 2 (b) is a schematic diagram of the one-way valve 30 in the open state. The elastic member 322 provides an elastic force F1 to the blocking member 321, and the blocking member 321 is pressed to block the air inlet 313a. When the force F2 exerted by the gas inside the shell on the blocking member 321 is greater than the elastic force F1 of the elastic member 322, the gas inside the shell can overcome the elastic force of the elastic member 322 and push the blocking member 321 to open the air inlet 313a, allowing the gas inside the shell to enter the valve chamber 313 and then be discharged to the outside of the shell through the air outlet 313b. Conversely, after the gas inside the shell is discharged and the force F2 exerted by the gas inside the shell on the blocking member 321 is less than the elastic force F1 of the elastic member 322, the elastic member 322 can drive the blocking member 321 to reset, thereby blocking the air inlet 313a.

[0118] Optionally, the elastic member 322 is an elastic member, and its structure can be various, such as a shrapnel, a spring, or elastic rubber. Exemplarily, the elastic member 322 is a spring. Using a spring as the elastic member 322 disposed in the valve cavity 313, on the one hand, facilitates the assembly of the elastic member 322, which helps to reduce the difficulty of assembling the elastic member 322 in the valve cavity 313, and on the other hand, enables the direction in which the elastic member 322 applies the elastic force to the blocking member 321 to be relatively stable. In some embodiments, the material of the elastic member 322 includes steel, iron, or aluminum. The elastic member 322 made of steel, iron, or aluminum has good toughness and can alleviate the phenomenon of elastic failure of the elastic member 322, which helps to increase the service life of the elastic member 322.

[0119] Exemplarily, the elastic member 322 is a spring, and the sealing and opening of the valve chamber 313 are achieved through the deformation of the spring. When sealing the valve chamber 313, the spring's initial length can be set to L0, which is the natural length of the spring before compression. The spring's assembly space within the valve chamber 313 is L1, and the valve chamber 313 is configured such that L0 > L1. After assembly, the spring is compressed, exerting a compressive force F1 on the sealing member 321, forcing the sealing member 321 to tightly fit against the wall of the valve chamber 313, achieving a sealing effect.

[0120] When the air pressure inside the housing increases to a certain value P1, the air pressure exerts a force F2 on the lower surface 31222d of the sealing member 321. When F2 is greater than the spring compression force F1, the sealing interface fails, and the gas inside the housing enters the valve chamber 313 and is discharged to the outside of the housing through the channel within the valve chamber 313. As the gas inside the housing is discharged, the internal air pressure decreases. When the air pressure reaches a certain value P2, the valve body 31 closes to achieve a seal. The valve body 31 can be repeatedly opened and closed to exhaust air, so that the air pressure inside the housing is maintained between P1 and P2, thereby preventing the pressure relief mechanism 70 from opening prematurely due to excessive internal housing pressure.

[0121] Please refer to Figures 2, 3a, and 3b. Figure 3a is a schematic structural diagram of the blocking member 321 of the one-way valve 30 according to one or more embodiments; Figure 3b is a schematic cross-sectional structural diagram of the one-way valve 30 according to one or more embodiments. According to some embodiments of the present application, the elastic member 322 is arranged along the axial direction Y of the valve cavity 313, and the two ends of the elastic member 322 respectively abut against the blocking member 321 and the cavity top surface of the valve cavity 313, and the elastic member 322 is in a compressed state and is located between the cavity top surface of the valve cavity 313 and the blocking member 321, so that the elastic member 322 can apply elastic force to the blocking member 321, so that the blocking member 321 can abut against the cavity bottom surface of the valve cavity 313 to block the air inlet 313a.

[0122] Furthermore, a plurality of limiting protrusions 3212 a may be provided on the outer circumferential surface of the blocking member 321 . The plurality of limiting protrusions 3212 a are arranged at intervals along the circumference of the blocking member 321 , and the limiting protrusions 3212 a cooperate with the side surfaces of the valve cavity 313 for guidance.

[0123] The limiting protrusion 3212a cooperates with the side surface of the valve cavity 313 to guide and limit the position of the valve. Specifically, the limiting protrusion 3212a cooperates with the wall surface of the valve cavity 313 when the blocking member 321 moves along the axis of the valve cavity 313 to provide guidance and position limiting functions. Of course, in other embodiments, the one-way valve 30 may also have other structures. For example, the side surface of the valve cavity 313 may be provided with a guide groove (not shown) extending along the axis of the valve cavity 313, and the limiting protrusion 3212a extends into the guide groove. The limiting protrusion 3212a can move in the guide groove along the axis of the valve cavity 313 when the blocking member 321 opens the air inlet 313a to provide guidance and position limiting functions. Multiple guide grooves may be provided, and each of the multiple guide grooves cooperates with a plurality of limiting protrusions 3212a. Optionally, the limiting protrusion 3212a may have various shapes, such as semicircular, triangular, trapezoidal or rectangular structures. For example, in FIG. 3a , the limiting protrusion 3212a has a semicircular shape.

[0124] By providing a plurality of spaced-apart limiting protrusions 3212a on the outer peripheral surface of the blocking member 321, and the limiting protrusions 3212a cooperate with the side surfaces of the valve cavity 313 to guide the blocking member 321, the blocking member 321 can be guided and limited by the cooperation between the limiting protrusions 3212a and the side surfaces of the valve cavity 313 when the blocking member 321 moves along the axial direction of the valve cavity 313, thereby improving the stability of the movement of the blocking member 321.

[0125] Please refer to Figures 2, 3b, and 4. Figure 4 is a schematic diagram of the exploded structure of a one-way valve 30 according to one or more embodiments. The valve body 31 includes a valve seat 311 and a valve cover 312. The valve cover 312 and the valve seat 311 enclose a valve chamber 313. The ends of the elastic member 322 respectively abut against the blocking member 321 and the cover top wall 3121 of the valve cover 312. A first guide post 31211 can be protruded from the cover top wall 3121 on the side facing the blocking member 321. The elastic member 322 is partially sleeved on the outside of the first guide post 31211 to achieve positioning of the elastic member 322.

[0126] Furthermore, the blocking member 321 includes a pressing portion 3212 and a sealing portion 3211, the two ends of the elastic member 322 respectively abut against the valve cover 312 and the pressing portion 3212, the sealing portion 3211 is connected to the side of the pressing portion 3212 away from the valve cover 312, and the sealing portion 3211 is used to block the air inlet 313a. The rigidity of the pressing portion 3212 is greater than that of the sealing portion 3211. The sealing portion 3211 is connected to the side of the pressing portion 3212 away from the top wall 3121 of the cover. The sealing portion 3211 is used to seal the air inlet 313a. The elastic member 322 is arranged between the top wall 3121 of the cover and the pressing portion 3212. The pressing portion 3212 can be pressed against the sealing portion 3211 under the elastic force of the elastic member 322, so that the upper surface 31222c of the sealing portion 3211 is effectively in contact with the pressing portion 3212, so that the sealing portion 3211 is against the bottom surface of the valve cavity 313, thereby sealing the air inlet 313a through the sealing portion 3211.

[0127] According to some embodiments of the present application, the rigidity of the pressing portion 3212 is greater than the rigidity of the sealing portion 3211, and the setting of the pressing portion 3212 can effectively transmit the force applied by the elastic member 322 to the sealing portion 3211. In other words, the rigidity of the pressing portion 3212 is greater than the rigidity of the sealing portion 3211, that is, the deformation resistance of the pressing portion 3212 is greater than the deformation resistance of the sealing portion 3211, so that the pressing portion 3212 can better press the sealing portion 3211 on the bottom surface of the installation cavity to seal the air inlet 313a. Exemplarily, the material of the pressing portion 3212 can be a variety, such as steel, iron or aluminum. Similarly, the material of the sealing portion 3211 can also be a variety, such as rubber, silicone or plastic.

[0128] Optionally, the connection structure between the pressing portion 3212 and the sealing portion 3211 can be various, such as clamping, bolting, or bonding.

[0129] By setting the sealing member 321 to include a pressing portion 3212 and a sealing portion 3211, the pressing portion 3212 is set on the side of the sealing portion 3211 facing the valve cover 312, and the sealing portion 3211 is used to seal the air inlet 313a, and the two ends of the elastic member 322 are respectively against the valve cover 312 and the pressing portion 3212, so that the elastic member 322 can exert an elastic force on the sealing portion 3211 through the pressing portion 3212, which is beneficial to improve the balance of the elastic force of the elastic member 322 acting on the sealing portion 3211, and thus can effectively improve the sealing effect of the sealing portion 3211 on the air inlet 313a.

[0130] According to some embodiments of the present application, the sealing portion 3211 is made of a material that is resistant to electrolyte, such as fluororubber, PFA, EPDM, etc. Different sealing materials have different physical properties, and accordingly, different forces are required to achieve sealing.

[0131] For example, the limiting protrusion 3212a is provided on the outer circumferential surface of the pressing portion 3212. Of course, in other embodiments, the blocking member 321 may be formed as a single sealing component, such as a rubber pad or a silicone pad. That is, the blocking member 321 only includes the sealing portion 3211, and the two ends of the elastic member 322 respectively abut against the valve cover 312 and the sealing portion 3211. Of course, in other embodiments, the valve core 32 may also be formed as a single elastic component, such as elastic rubber.

[0132] Similarly, a second guide post 3212 b may be protruded from the side of the pressing portion 3212 facing the cover top wall 3121 , and a portion of the elastic member 322 is sleeved on the outer side of the second guide post 3212 b .

[0133] The one-way valve 30 adopting this structure can, on the one hand, play a certain positioning role for the elastic member 322 through the first guide column 31211 and the second guide column 3212b, so as to facilitate the assembly of the elastic member 322 and help reduce the difficulty of assembling the elastic member 322. On the other hand, the first guide column 31211 and the second guide column 3212b can play a certain guiding role when the elastic member 322 is compressed, thereby reducing the radial deformation of the elastic member 322 during the compression process, thereby achieving stable compression of the elastic member 322, which is conducive to improving the reliability of the elastic member 322 and further reducing the risk of the sealing member 321 accidentally opening the air inlet 313a. The elastic member 322 can be a spring. Of course, in other embodiments, the elastic member 322 can also be a spring or elastic rubber.

[0134] Please refer to Figures 3b and 3c in conjunction. Figure 3c is a schematic diagram of the elastic member 322 according to one or more embodiments. According to some embodiments of the present application, the ends of the elastic member 322 respectively abut against a side surface of the valve cover 312 facing the valve cavity 313 and a side surface of the pressing portion 3212 facing the valve cover 312, with the distance between the two being the assembly space L1 of the elastic member 322. Specifically, the cover top wall 3121 has a side surface 3121a facing the valve cavity 313, and the pressing portion 3212 has a side surface 3212c facing the cover top wall 3121. L1 is the distance between the 3121a surface and the 3212c surface.

[0135] According to some embodiments of the present application, along the axial direction Y of the valve cavity 313 , the size of the gap between the valve cover 312 and the blocking member 321 is H1 , satisfying 0 mm < H1 ≤ 0.5 mm.

[0136] A first guide post 31211 is protruding from the side of the valve cover 312 facing the sealing member 321, and a second guide post 3212b is protruding from the side of the sealing member 321 facing the valve cover 312. The gap between the valve cover 312 and the sealing member 321 is the distance between the end surface of the first guide post 31211 facing away from the valve cover 312 and the end surface of the second guide post 3212b facing the valve cover 312. As shown in FIG3b , H1. In other words, in the axial direction Y of the valve cavity 313, the sum of the height H2 of the first guide post 31211 and the height H3 of the second guide post 3212b is less than the assembly space L of the elastic member 322. That is, in the axial direction, the height H2 of the first guide post 31211 + the height H3 of the second guide post 3212b < the spring compression space L1.

[0137] For example, the size H1 of the gap between the valve cover 312 and the blocking member 321 may be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, etc.

[0138] By setting the size of the gap between the valve cover 312 and the sealing member 321 in the axial direction Y to be greater than 0 mm and less than or equal to 5 mm, on the one hand, the obstruction of the valve cover 312 to the sealing member 321 can be reduced, so that there is space between the valve cover 312 and the sealing member 321 for the sealing member 321 to move along the axial direction Y, so that when the gas inside the shell pushes the sealing member 321, the sealing member 321 can open the air inlet 313a for exhaust. On the other hand, it can alleviate the phenomenon that the one-way valve 30 occupies too much space in the axial direction Y due to the excessive gap between the valve cover 312 and the sealing member 321, which is beneficial to improving the space utilization rate of the battery cell 20.

[0139] As shown in Figure 3c, taking the elastic member 322 as a spring as an example, the initial length L0 of the spring is the natural length of the spring before it is compressed; by configuring L0>L1, the spring can have a certain initial elastic force after being assembled into the valve cavity 313, so as to push the sealing part 3211 to be pressed against the wall of the valve cavity 313, thereby improving the sealing performance.

[0140] Furthermore, the physical length L2 of the spring is configured such that L1 > L2. The physical length of the spring is the length of the main body of the spring after it is fully compressed. As shown in Figure 3c, State 1 in Figure 3c represents the uncompressed state of the spring. In this state, there are gaps between the physical structures of the spring, allowing further compression. State 2 in Figure 3c represents the fully compressed state of the spring. In this state, there are no gaps between the physical structures of the spring, preventing further compression. The physical length of the spring L2 = d1 * n1 + d2 + d3, where d1 is the spring wire diameter, n1 is the maximum number of axial turns of the spring, d2 is the thickness of the outermost spring at one end, and d3 is the thickness of the outermost spring at the other end. As shown in Figures 3b and 3c, the spring is a helical cylindrical coil, and the spring wire diameter d1 is the diameter of each coil of the spring. As the number of coils increases, the physical length of the spring becomes the sum of the physical lengths of each coil, i.e., d1 * n1. As shown in Figure 3b, the spring has four coils, and the physical length of this portion after full compression is d1 * 4. The end of the spring can be ground flat to facilitate assembly. The so-called grinding process refers to grinding a part of the originally cylindrical spring entity to make its top surface smoother. After the grinding process, the spring entity becomes thinner, that is, it is no longer a complete cylinder. Then the thickness d2 and d3 of the spring entity in this area will be less than the spring wire diameter d1; of course, in some embodiments, the end of the spring can also not be processed. In this case, the thickness of the spring entity is equal to the spring wire diameter d1, that is, d2≤d1, d3≤d1. Therefore, the overall length of the spring entity is L2=d1*n1+d2+d3. By setting L1>L2, the spring will not be completely compacted after assembly, and there is still room for compression activity.

[0141] According to some embodiments of the present application, the compression margin of the elastic member 322 located in a compressed state between the valve cover 312 and the blocking member 321 is greater than or equal to 0.5 mm, that is, L1-L2>0.5 mm. This allows the elastic member 322 to have sufficient compression margin for the blocking member 321 to move along the axial direction Y of the valve cavity 313, so that the blocking member 321 can open the air inlet 313a. If the elastic member 322 is a spring, then in the axial direction Y of the valve cavity 313, the sum of the gaps between the spring coils is greater than or equal to 0.5 mm. For example, L1-L2 can be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, etc.

[0142] Please continue to refer to FIG. 3 b . According to some embodiments of the present application, the diameter of the first guide column 31211 is D1 , and the inner diameter of the elastic member 322 is D2 , satisfying the condition: 0 mm < D2 − D1 ≤ 5 mm.

[0143] The elastic member 322 is a spring, and the inner diameter D2 of the elastic member 322 is the diameter of the cavity formed inside the spring. 0mm<D2-D1≤5mm. That is, when the first guide post 31211 and the elastic member 322 are coaxially arranged, the gap between the first guide post 31211 and the elastic member 322 is greater than 0mm and less than or equal to 5mm.

[0144] Exemplarily, the difference between the inner diameter of the elastic member 322 and the diameter of the first guide column 31211 can be 0mm, 0.1mm, 0.2mm, 0.5mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm or 5mm, etc.

[0145] By setting the difference between the inner diameter of the elastic part 322 and the diameter of the first guide column 31211 to be greater than 0 mm and less than or equal to 5 mm, on the one hand, the phenomenon that the elastic part 322 is not convenient to be assembled on the first guide column 31211 due to the difference between the inner diameter of the elastic part 322 and the diameter of the first guide column 31211 being less than or equal to 0 can be alleviated, so as to reduce the scratching phenomenon when the elastic part 322 is sleeved on the first guide column 31211. On the other hand, the phenomenon that the gap between the elastic part 322 and the first guide column 31211 is too large due to the large difference between the inner diameter of the elastic part 322 and the diameter of the first guide column 31211 can be alleviated, so as to reduce the radial movement or radial deformation of the elastic part 322, thereby improving the balance of the elastic force of the elastic part 322 acting on the blocking part 321, so as to reduce the risk of the blocking part 321 accidentally opening the air inlet 313a.

[0146] Please continue to refer to FIG. 3 b . According to some embodiments of the present application, the diameter of the second guide column 3212 b is D3 , and the inner diameter of the elastic member 322 is D2 , satisfying the condition: 0 mm < D3 − D1 ≤ 5 mm.

[0147] The elastic member 322 is a spring, and the inner diameter D2 of the elastic member 322 is the diameter of the cavity formed inside the spring.

[0148] 0mm<D3-D1≤5mm, that is, when the second guide post 3212b and the elastic member 322 are coaxially arranged, the size of the gap between the second guide post 3212b and the elastic member 322 is greater than 0mm and less than or equal to 5mm.

[0149] Exemplarily, the difference between the inner diameter of the elastic member 322 and the diameter of the second guide column 3212b can be 0mm, 0.1mm, 0.2mm, 0.5mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm or 5mm, etc.

[0150] By setting the difference between the inner diameter of the elastic member 322 and the diameter of the second guide post 3212b to be greater than 0 mm and less than or equal to 5 mm, on the one hand, the phenomenon that the elastic member 322 is not convenient to be assembled on the second guide post 3212b due to the difference between the inner diameter of the elastic member 322 and the diameter of the second guide post 3212b being less than or equal to 0 can be alleviated, thereby reducing the scratching phenomenon when the elastic member 322 is sleeved on the second guide post 3212b. On the other hand, the phenomenon that the gap between the elastic member 322 and the second guide post 3212b is too large due to the large difference between the inner diameter of the elastic member 322 and the diameter of the second guide post 3212b can be alleviated, thereby reducing the radial movement or radial deformation of the elastic member 322, thereby improving the balance of the elastic force of the elastic member 322 acting on the blocking member 321, thereby reducing the risk of the blocking member 321 accidentally opening the air inlet 313a.

[0151] In this embodiment, the valve core 32 is arranged in the valve cavity 313, so that the valve core 32 can block the air inlet channel, and when the pressure inside the shell rises, the gas inside the shell can act on the valve core 32 and drive the valve core 32 to open the air inlet channel, so as to realize the one-way exhaust function of the one-way valve 30, so that the one-way valve 30 can discharge the gas inside the shell to the outside of the shell.

[0152] According to some embodiments of the present application, the opening pressure of the valve core 32 is greater than or equal to 0.2 MPa; alternatively, greater than or equal to 0.4 MPa; and further alternatively, greater than or equal to 0.8 MPa. For example, the opening pressure of the valve core 32 can be 0.20 MPa, 0.25 MPa, 0.30 MPa, 0.35 MPa, 0.40 MPa, 0.45 MPa, 0.50 MPa, 0.55 MPa, 0.60 MPa, 0.65 MPa, 0.70 MPa, 0.75 MPa, 0.80 MPa, 0.90 MPa, or 1.00 MPa.

[0153] The one-way valve opening pressure test method and principle can be tested based on the helium leakage standard. The helium leakage standard is defined as follows: if the leakage rate is less than 10^-6Pa.m^3 / s, the system is considered to be sealed; if the leakage rate is greater than 10^-6Pa.m^3 / s, it indicates that there is a gas leak in the system.

[0154] During testing, the test chamber is sealed with a one-way valve and filled with helium. The amount of helium in the test chamber environment is monitored using a helium detector. If helium is detected and the leakage rate is greater than 10^-6Pa.m^3 / s, it means that the test chamber is no longer sealed and helium is leaking out. The helium leakage rate is continuously monitored. When the leakage rate is greater than 10^-5Pa.m^3 / s, the one-way valve is determined to be open for release. The pressure in the test chamber at this time is recorded as the opening pressure of the one-way valve.

[0155] According to some embodiments of the present application, a battery cell 20 includes an end cap 21. The end cap 21 includes an outer surface 21a and an inner surface 21b disposed opposite each other, with the outer surface 21a facing the exterior of the housing and the inner surface 21b facing the interior of the housing. A one-way valve 30 is disposed on the end cap 21. The valve body 31 of the one-way valve 30 may face the exterior of the housing and at least partially protrude from the outer surface 21a of the end cap 21, or the valve body 31 of the one-way valve 30 may face the interior of the housing and at least partially protrude from the inner surface 21b of the end cap 21.

[0156] Please refer to Figures 4, 5, and 6. Figure 5 is a front view of a one-way valve 30 according to one or more embodiments, and Figure 6 is a partial cross-sectional structural schematic diagram of a battery cell 20 according to one or more embodiments. According to some embodiments of the present application, the end cap 21 includes an outer surface 21a and an inner surface 21b disposed opposite each other, with the outer surface 21a facing the exterior of the housing and the inner surface 21b facing the interior of the housing. The one-way valve 30 is disposed on the end cap 21, and the valve body 31 of the one-way valve 30 is disposed on the outer surface 21a, with at least a portion of the valve body 31 protruding from the outer surface 21a of the end cap 21.

[0157] In this embodiment, the one-way valve 30 includes a valve body 31 and a valve core 32. The valve body 31 defines a valve cavity 313, and the valve core 32 is disposed within the valve cavity 313. The valve body 31 includes a valve seat 311 and a valve cover 312. The valve cover 312 includes a cover top wall 3121 and a cover side wall 3122 connected to the cover top wall 3121. The cover top wall 3121, the cover side wall 3122, and the valve seat 311 enclose a valve cavity 313. The valve seat 311 is provided with an air inlet 313a for the valve cavity 313, connecting the valve cavity 313 with the interior of the housing. The valve cover 312 is provided with an air outlet 313b for the valve cavity 313, connecting the valve cavity 313 with the exterior of the housing. The valve core 32 is used to block the air inlet channel of the valve cavity 313. The valve core 32 is configured to open the air inlet channel in response to gas inside the housing, thereby releasing gas from the battery cell 20. In this embodiment, the valve core 32 directly blocks the air inlet 313a of the valve cavity 313. The air inlet passage includes a gas flow path from the inside of the battery cell 20 shell to the air inlet 313a of the valve cavity 313 and to the side where the air inlet 313a is discharged.

[0158] In this embodiment, the valve body 31 of the one-way valve 30 is provided with a valve seat 311 and a valve cover 312. The one-way valve 30 with this structure is provided with the valve body 31 as two parts, so that it is convenient to assemble the valve core 32 into the valve cavity 313, which is beneficial to reduce the difficulty of assembling the one-way valve 30.

[0159] Continuing with Figures 4 and 6 , according to some embodiments of the present application, the valve seat 311 has a first through hole 3111 extending through the valve seat 311, and the air inlet 313a is the first through hole 3111, that is, the first through hole 3111 serves as the air inlet 313a of the valve cavity 313. The cover sidewall 3122 has a second through hole 31221 extending through the cover sidewall 3122, and the air outlet 313b is the second through hole 31221, that is, the second through hole 31221 serves as the air outlet 313b of the valve cavity 313. This arrangement facilitates the outward transmission of gas from within the battery 100.

[0160] According to some embodiments of the present application, the second through hole 31221 extends to the end of the cover side wall 3122 in a direction away from the cover top wall 3121. As shown in Figure 4, the direction away from the cover top wall 3121 is the direction from the cover top wall 3121 toward the valve seat 311 (direction X in the figure). The second through hole 31221 is formed by removing part of the structure of the cover side wall 3122. Along the X direction, the cover side wall 3122 is hollowed out directly to the bottom end of the cover side wall 3122. In further embodiments, along the X direction, the lower opening surface of the second through hole 31221 can be flush with the sealing surface of the blocking member 321, that is, the sealing interface is higher than or flush with the bottom wall of the second through hole 31221. Through this arrangement, when the one-way valve 30 is opened to exhaust, that is, when the sealing member 321 opens the sealing interface, the electrolyte liquid carried out with the gas can be discharged outward in time, so that the electrolyte is not easy to accumulate on the outer edge of the sealing member 321, thereby effectively ensuring the sealing and repeated opening function of the one-way valve 30.

[0161] According to some embodiments of the present application, there are multiple second through holes 31221, and the multiple second through holes 31221 are spaced apart in the circumferential direction of the cover side wall 3122. This arrangement allows for faster exhaust of gas when the one-way valve 30 is opened for exhaust, shortening the exhaust time, that is, shortening the time that the battery 100 housing is in the open state, thereby reducing the intrusion of external moisture into the battery 100 system during the valve opening period.

[0162] Please refer to Figure 7, which is a schematic cross-sectional view of the one-way valve 30 according to one or more embodiments. According to some embodiments of the present application, a first guide post 31211 is protruding from the side of the cover top wall 3121 facing the blocking member 321, and a portion of the elastic member 322 is sleeved around the outside of the first guide post 31211. The cover top wall 3121 has a third through hole 31212 extending through the cover top wall 3121 and the first guide post 31211, and the air outlet 313b is the third through hole 31212. Specifically, the third through hole 31212 serves as the air outlet 313b of the valve chamber 313. This arrangement facilitates the outward transmission of gas from within the battery 100.

[0163] Please continue to refer to Figures 4, 5, 6 and 7. According to some embodiments of the present application, the valve cover 312 also includes a flange wall 31222, the cover side wall 3122 connects the cover top wall 3121 and the flange wall 31222, the flange wall 31222 extends toward a side away from the valve cavity 313 relative to the cover side wall 3122, and the flange wall 31222 is connected to the valve seat 311.

[0164] According to some embodiments of the present application, the valve cover 312 is connected to the valve seat 311. Specifically, a first recessed groove 3112 is provided on the side of the valve seat 311 facing the valve cover 312, which is recessed relative to the surface of the valve seat 311. At least a portion of the flange wall 31222 is accommodated in the first recessed groove 3112 and connected to the valve seat 311.

[0165] In this embodiment, a first recess 3112 is provided on the side of the valve seat 311 facing the valve cover 312, and at least a portion of the flange wall 31222 is accommodated in the first recess 3112. The one-way valve 30 adopting such a structure can, on the one hand, save the space occupied by the valve body 31 in the thickness direction of the end cover 21, and on the other hand, improve the structural stability of the valve cover 312 assembled on the valve seat 311.

[0166] According to some embodiments of the present application, the flange wall 31222 is housed within the first recess 3112 and connected to the valve seat 311. The thickness of the flange wall 31222 is less than or equal to the depth of the first recess 3112, so that after the flange wall 31222 is connected to the valve seat 311, the surface of the flange wall 31222 facing the lid top wall 3121 is flush with the surface of the valve seat 311 facing the valve cover 312; or the surface of the flange wall 31222 facing the lid top wall 3121 is lower than the surface of the valve seat 311 facing the valve cover 312. As shown in Figures 6 and 7, after the valve cover 312 is connected to the valve seat 311, the flange wall 31222 is flush with the surface of the valve seat 311. This arrangement can reduce the overall installation height of the one-way valve 30.

[0167] According to some embodiments of the present application, the material of the valve seat 311 can be a metal material, such as copper, iron, aluminum, steel or aluminum alloy. Similarly, the material of the valve cover 312 can also be a metal material, such as copper, iron, aluminum, steel or aluminum alloy. The valve seat 311 and the valve cover 312 can be made of the same material or different materials. The valve cover 312 and the valve seat 311 can be assembled by welding (such as laser welding); they can also be assembled by mechanical interference, but the static friction generated by the interference must be greater than the rebound force of the elastic member 322.

[0168] According to some embodiments of the present application, the flange wall 31222 is welded to the valve seat 311. Specifically, the flange wall 31222 is an annular component having a certain thickness, and the outer peripheral surface of the flange wall 31222 is welded to the groove wall surface of the first sink 3112 as a connecting surface 31222a. Furthermore, the connecting surface 31222a of the flange wall 31222 can be set as an inclined surface, and the groove wall surface of the first sink 3112 can also be set as an inclined surface, so that the connecting surface 31222a of the flange wall 31222 is matched with the groove wall surface of the first sink 3112. As shown in Figures 6 and 7, the flange wall 31222 and the first sink 3112 can form an interlocking structure. In this way, the welding quality can be improved and the strength and stability of the connection can be enhanced. Furthermore, it is preferred that the valve cover 312 and the valve seat 311 are made of the same material to achieve better welding quality.

[0169] According to some embodiments of the present application, at least a portion of the first weld mark W1 of the flange wall 31222 welded to the valve seat 311 is staggered with the second through-hole 31221 along the circumference of the cover sidewall 3122. As shown in FIG5 , welding can be performed at a location on the cover sidewall 3122 where no second through-hole 31221 is formed. There can be multiple first weld marks W1, distributed along the circumference of the cover sidewall 3122, and the distribution of the first weld marks W1 can be staggered with the distribution of the second through-hole 31221. In other words, multiple second through-holes 31221 are spaced apart along the circumference of the cover sidewall 3122, and the locations between adjacent second through-holes 31221 where no holes are formed have a solid wall. Welding can be performed at locations with solid walls. In this way, the solid wall has a certain heat-blocking effect, which can protect the sealing part 321 of the valve core 32 and reduce the impact of high temperature during welding on the sealing part 321, so as to prevent the sealing part 321 from being deformed by heat, thereby causing the sealing interface to fail when the valve is not opened.

[0170] Please refer to Figures 8, 9, 10 and 11. Figure 8 is a front view of the one-way valve 30 according to one or more embodiments, Figure 9 is a bottom view of the one-way valve 30 according to one or more embodiments, and Figure 10 is a schematic diagram of the exploded structure of the one-way valve 30 according to one or more embodiments. Figure 11 is a schematic diagram of the partial cross-sectional structure of the battery cell 20 according to one or more embodiments. According to some embodiments of the present application, the valve seat 311 is connected to the valve cover 312. Specifically, the valve cover 312 includes a flange wall 31222, and the valve seat 311 is connected to the flange wall 31222. In other words, the valve seat 311 is connected to the flange wall 31222 of the valve cover 312.

[0171] According to some embodiments of the present application, a connecting protrusion 3113 is convexly provided on the outer peripheral surface of the valve seat 311 , and a receiving groove 31222b is provided on the inner peripheral surface of the flange wall 31222 . The connecting protrusion 3113 is accommodated in the receiving groove 31222b and connected to the flange wall 31222 .

[0172] There are multiple connecting protrusions 3113, spaced apart along the circumference of the valve seat 311. There are multiple corresponding receiving grooves 31222b, with the number of connecting protrusions 3113 being the same as the number of receiving grooves 31222b. The shape of the connecting protrusions 3113 matches the shape of the receiving grooves 31222b, allowing the connecting protrusions 3113 to be accommodated within the receiving grooves 31222b. With this arrangement, after the valve cover 312 is connected to the valve seat 311, the flange wall 31222 is flush with the surface of the valve seat 311. In this manner, the valve seat 311 is embedded in the valve cover 312, reducing the overall installation height of the one-way valve 30. Comparing Figure 6 and Figure 11, in the scheme of Figure 6, the valve cover 312 is connected to the valve seat 311, and its installation height is the thickness of the valve cover 312 superimposed on the partial thickness of the valve seat 311; in the scheme of Figure 11, the valve seat 311 is connected to the valve cover 312, the valve seat 311 is completely accommodated, and its installation height is the thickness of the valve cover 312; compared with the former, the installation height of this embodiment is lower, reducing the space occupancy rate.

[0173] According to some embodiments of the present application, the connecting protrusion 3113 is welded to the flange wall 31222. The flange wall 31222 has an upper surface 31222c and a lower surface 31222d disposed opposite each other, with the upper surface 31222c facing the lid top wall 3121. A second weld mark W2, where the connecting protrusion 3113 is welded to the flange wall 31222 of the lid side wall 3122, is located on the lower surface 31222d of the flange wall 3122. In other words, welding is performed from the underside of the valve cover 312 and valve seat 311. As shown in FIG11 , the second weld mark W2 is located on the side away from the valve cavity 313. This provides a certain degree of heat insulation for the valve seat 311 and flange wall 31222, protecting the sealing member 321 of the valve core 32 and reducing the impact of high temperatures during welding on the sealing member 321. This prevents deformation of the sealing member 321 due to heat, which could lead to failure of the sealing interface when the valve is not opened.

[0174] Please refer to Figure 12, which is a schematic partial cross-sectional view of a battery cell 20 according to one or more embodiments. According to some embodiments of the present application, a one-way valve 30 is disposed on the outer surface 21a of the end cap 21, with the valve body 31 of the one-way valve 30 facing the exterior of the housing, and at least a portion of the valve body 31 protruding from the outer surface 21a of the end cap 21.

[0175] In this embodiment, the one-way valve 30 includes a valve body 31 and a valve core 32. The valve body 31 defines a valve cavity 313, and the valve core 32 is disposed within the valve cavity 313. The valve body 31 includes a valve cover 312, which includes a cover top wall 3121 and a cover side wall 3122 connected to the cover top wall 3121. The cover top wall 3121, the cover side wall 3122, and the end cap 21 enclose the valve cavity 313. The end cap 21 is provided with an air inlet 313a for the valve cavity 313, connecting the valve cavity 313 with the interior of the housing; the valve cover 312 is provided with an air outlet 313b for the valve cavity 313, connecting the valve cavity 313 with the exterior of the housing. The valve core 32 is used to block the air inlet channel of the valve cavity 313. The valve core 32 is configured to open the air inlet channel in response to gas inside the housing, thereby releasing gas from the battery cell 20. In this embodiment, the valve core 32 directly blocks the air inlet 313a of the valve cavity 313. The air inlet passage includes a gas flow path from the inside of the battery cell 20 shell to the air inlet 313a of the valve cavity 313 and to the side where the air inlet 313a is discharged.

[0176] In this embodiment, the valve body 31 of the one-way valve 30 can consist solely of a valve cover 312 without a valve seat 311. The valve cover 312 is directly connected to the end cap 21; alternatively, the end cap 21 can serve as the valve seat 311 for the valve body 31. This approach reduces the installation height of the one-way valve 30. Comparing Figures 6, 11, and 12, in Figure 6, the valve cover 312 is connected to the valve seat 311, and its installation height is the thickness of the valve cover 312 superimposed on the thickness of the valve seat 311, and then on the thickness of the end cap 21. In Figure 11, the valve seat 311 is connected to the valve cover 312, completely enclosing it. Its installation height is the thickness of the valve cover 312 superimposed on the thickness of the end cap 21. In Figure 12, the valve cover 312 can be embedded in the end cap 21, and its installation height can be the thickness of the end cap 21. Compared to the three embodiments, this embodiment has a lower installation height, reducing space usage.

[0177] According to some embodiments of the present application, the end cap 21 is provided with a first vent 291, which connects the interior of the housing with the exterior of the housing. The air inlet 313a is the first vent 291, that is, the first vent 291 serves as the air inlet 313a of the valve chamber 313. The side wall 3122 of the cover has a second through hole 31221 that passes through the side wall 3122 of the cover. The air outlet 313b is the second through hole 31221, that is, the second through hole 31221 serves as the air outlet 313b of the valve chamber 313. This arrangement facilitates the outward transmission of gas from the interior of the battery 100. In other embodiments, the air outlet 313b can also be a third through hole 31212 located on the top wall 3121 of the cover and passing through the top wall 3121 and the first guide post 31211. Please refer to Figure 7 and the previous description for details, which will not be repeated here.

[0178] According to some embodiments of the present application, a second groove (not shown in the figure) is provided on the side of the end cover 21 facing the outside of the shell, which is recessed relative to the outer surface 21a of the end cover 21, and at least a portion of the flange wall 31222 of the valve cover 312 is accommodated in the second groove and connected to the end cover 21.

[0179] In this embodiment, a second groove is provided on the side of the end cover 21 facing the outside of the shell, and at least a portion of the flange wall 31222 is accommodated in the second groove. The one-way valve 30 adopting this structure can save the space occupied by the valve body 31 in the thickness direction of the end cover 21.

[0180] According to some embodiments of the present application, the flange wall 31222 is housed within the second recess and connected to the end cap 21. The thickness of the flange wall 31222 is less than or equal to the depth of the second recess, such that after the flange wall 31222 is connected to the end cap 21, the surface of the flange wall 31222 facing the cover top wall 3121 is flush with the surface of the end cap 21 facing the exterior of the housing; or the surface of the flange wall 31222 facing the cover top wall 3121 is lower than the surface of the end cap 21 facing the exterior of the housing. As shown in Figure 12, after the valve cover 312 is connected to the end cap 21, the flange wall 31222 is flush with the surface of the end cap 21. This arrangement can reduce the overall installation height of the one-way valve 30.

[0181] According to some embodiments of the present application, the flange wall 31222 is welded to the end cover 21. Specifically, the flange wall 31222 is an annular component having a certain thickness, and the outer peripheral surface of the flange wall 31222 is welded to the groove wall surface of the second sink trough as a connecting surface 31222a. Furthermore, the connecting surface 31222a of the flange wall 31222 can be set as an inclined surface, and the groove wall surface of the second sink trough can also be set as an inclined surface accordingly, so that the connecting surface 31222a of the flange wall 31222 fits with the groove wall surface of the second sink trough. As shown in Figure 12, the flange wall 31222 and the second sink trough can form an interlocking structure. In this way, the welding quality can be improved, and the strength and stability of the connection can be enhanced. Furthermore, it is preferred that the valve cover 312 and the end cover 21 are made of the same material to achieve better welding quality. For example, both are made of aluminum.

[0182] Please refer to Figure 6 in conjunction with Figures 13, 14, and 15. Figure 13 is a schematic diagram of a partial cross-sectional structure of an end cap 21 according to one or more embodiments; Figure 14 is a front view of the end cap 21 of a battery cell 20 according to one or more embodiments. Figure 15 is a schematic diagram of a partial exploded structure of a battery cell 20 according to one or more embodiments. According to some embodiments of the present application, a one-way valve 30 is provided on the end cap 21, with the valve body 31 of the one-way valve 30 facing the outside of the housing, and at least a portion of the valve body 31 protruding from the outer surface 21a of the end cap 21.

[0183] The end cap 21 is provided with a first vent 291. The first vent 291 includes a through-hole section 280 and a first hole section 281. The through-hole section 280 and the first hole section 281 are arranged along the thickness direction of the end cap 21. The through-hole section 280 connects the interior of the housing with the exterior of the housing. The first hole section 281 is located on the side of the through-hole section 280 facing away from the interior of the housing. The aperture of the first hole section 281 is larger than the aperture of the through-hole section 280. The one-way valve 30 is at least partially accommodated in the first hole section 281. The valve body 31 of the one-way valve 30 faces the exterior of the housing, and at least a portion of the valve body 31 protrudes from the outer surface 21a of the end cap 21. As shown in FIG. 13 , the first vent 291 is a countersunk hole that is recessed relative to the outer surface 21a of the end cap 21. When the one-way valve 30 is connected to the end cap 21, a portion of the one-way valve 30 can be embedded in the first vent 291 to reduce the installation height.

[0184] Please refer to Figure 6. According to some embodiments of the present application, a first step surface 311b and a second step surface 311c are provided on the side of the valve seat 311 facing the valve cover 312. The first step surface 311b is closer to the valve cover 312 than the second step surface 311c. The first sink 3112 is provided on the first step surface.

[0185] The first hole section 281 includes a circumferentially arranged hole side surface, and the outer peripheral surface of the valve cover 312 / valve seat 311 of the one-way valve 30 is welded to the hole side surface. The outer peripheral surface of the second step is welded to the hole side surface.

[0186] According to some embodiments of the present application, the side surface of the hole matches the outer circumference of the valve cover 312 / valve seat 311 of the one-way valve 30, and both the side surface of the hole and the outer circumference of the valve cover 312 / valve seat 311 of the one-way valve 30 are arranged at an acute angle to the central axis of the first exhaust hole 291. This arrangement can enhance the connection strength.

[0187] According to some embodiments of the present application, the one-way valve 30 is welded to the end cap 21. As shown in FIG6 , the valve seat 311 of the one-way valve 30 can be welded to the end cap 21; specifically, the valve cap 312 of the one-way valve 30 is connected to the valve seat 311, and the valve seat 311 is welded to the end cap 21. In other embodiments, when the one-way valve 30 adopts the embodiment shown in FIG11 , the valve seat 311 of the one-way valve 30 can also be connected to the valve cap 312, and the valve cap 312 is welded to the end cap 21.

[0188] According to some embodiments of the present application, stress relief grooves are provided around the weld marks between the valve cover 312 / valve seat 311 and the end cover 21. These grooves may be provided only on the end cover 21, only on the valve cover 312 / valve seat 311, or on both the end cover 21 and the valve cover 312 / valve seat 311. Optionally, a first stress relief groove is provided on the side of the valve seat 311 / valve cover 312 facing the exterior of the housing; and / or a second stress relief groove is provided on the side of the wall facing the exterior of the housing.

[0189] Please refer to Figures 16, 17, 18 and 19. Figure 16 is a main view of the one-way valve 30 according to one or more embodiments, Figure 17 is a schematic diagram of the decomposed structure of the one-way valve 30 according to one or more embodiments, Figure 18 is a schematic diagram of the cross-sectional structure of the one-way valve 30 according to one or more embodiments; Figure 19 is a schematic diagram of the state of the one-way valve 30 according to one or more embodiments.

[0190] In this embodiment, the valve body 31 of the one-way valve 30 is provided with a weak area 3119. By providing the weak area 3119, when the internal pressure of the battery cell 20 is too high, the valve body 31 can break at the weak area 3119 to release the pressure of the battery cell 20 in time.

[0191] As shown in Figure 19, before opening, the valve body 31 of the one-way valve 30 is intact, and the valve core 32, under pressure, blocks the air inlet 313a, creating a sealed state. After opening, the valve body 31 of the one-way valve 30 is partially opened, and the sealing interface fails, allowing the pressure inside the battery cell 20 to be released.

[0192] In one embodiment, the weak zone 3119 comprises a thickness-weakened region, meaning that this region is relatively thinner than other regions of the valve body 31, thereby reducing the strength. In other embodiments, the weak zone 3119 may be constructed by selecting materials of varying strengths, such as materials of relatively low strength.

[0193] In one embodiment, the valve body 31 includes a valve cover 312, which includes a cover top wall 3121 and a cover side wall 3122 connected to the cover top wall 3121. The thickness weakened area 3119 includes a groove provided on the cover side wall 3122. By providing the groove on the cover side wall 3122, the thickness of the cover side wall 3122 in the area where the groove is located can be reduced, thereby achieving a weakened thickness.

[0194] In one embodiment, the groove is located on the side of the cover sidewall 3122 facing the valve cavity 313; or the groove is located on the side of the cover sidewall 3122 facing away from the valve cavity 313. In other words, the grooves can be provided on both the inside and outside of the cover sidewall 3122. The orthographic projections of the grooves on the cover sidewall 3122 at least partially overlap. This arrangement allows the cover sidewall 3122 to be thinned from both sides, reducing the thickness of the cover sidewall 3122 at the location where the grooves are provided, thereby achieving a thinner thickness and making it more susceptible to breaking when subjected to pressure.

[0195] In one embodiment, the cover sidewall 3122 has a second through hole 31221 extending therethrough, and the groove is provided on the connecting arm between two adjacent second through holes 31221. Multiple second through holes 31221 may be provided, and the plurality of second through holes 31221 are spaced apart circumferentially around the cover sidewall 3122. The provision of the second through holes 31221 can result in a partial loss of the cover sidewall 3122, which reduces its strength to a certain extent. Furthermore, the provision of a weakened area further increases its likelihood of breaking when subjected to pressure.

[0196] A groove may be provided on the connecting arm between two adjacent second through holes 31221. The groove may extend along the circumference of the valve cover 312 and may extend to both ends of the connecting arm. As shown in FIG16 , the thickness weakened area is a groove extending circumferentially along the cover sidewall 3122.

[0197] In one embodiment, the weakened area comprises a first score groove that is a circumferential groove surrounding the cover sidewall 3122 .

[0198] As shown in FIG16 , due to the provision of the second through hole 31221, the cover sidewall 3122 includes a solid area 3122a and a vent area 3122b in the direction of the axis Y of the valve chamber 313. In the circumferential direction of the valve chamber 313, the second through hole 31221 is provided on the cover sidewall 3122 in the vent area 3122b, making the cover sidewall 3122 discontinuous, while the cover sidewall 3122 in the solid area 3122a is a continuous, solid structure. Therefore, a weakened area can also be provided on the cover sidewall 3122 in the solid area 3122a. Specifically, the weakened area includes a first notch, which is a circumferential groove on the cover sidewall 3122.

[0199] In other embodiments, the grooves may be discontinuous along the circumference of the cover sidewall 3122. Specifically, the thickness weakened area includes a plurality of second scored grooves, which are spaced apart along the circumference of the cover sidewall 3122. In other words, a plurality of discontinuous grooves may be provided on the cover sidewall 3122 in the solid area 3122a.

[0200] Please refer to Figures 5, 8, and 16. The one-way valve 30 in this application may not include a weak area 3119, or it may include a weak area 3119. This can be selected as needed. In some embodiments, two types of one-way valves 30 may be provided on a single battery cell 20.

[0201] Please refer to Figures 20 and 21 in conjunction. Figure 20 is a front view of the end cap 21 of the battery cell 20 according to one or more embodiments. Figure 21 is a schematic diagram of the partially exploded structure of the battery cell 20 according to one or more embodiments. The one-way valve 30 with a weak area 3119 has a certain degree of pressure relief effect. Therefore, when this type of one-way valve 30 is selected, the pressure relief mechanism 70 may not be provided on the battery cell 20. Of course, when the one-way valve 30 with a weak area 3119 is selected, the pressure relief mechanism 70 can also be provided on the battery cell 20 at the same time. When the valve body 31 is provided with a weak area 3119, the actuation pressure of the pressure relief mechanism 70 is greater than the actuation pressure of the weak area 3119, and the actuation pressure of the weak area 3119 is greater than the opening pressure of the one-way valve 30. With this arrangement, when a battery cell 20 experiences thermal runaway, the gas inside the outer shell of the battery cell 20 will rapidly surge, opening the pressure relief mechanism 70 for pressure relief. However, during normal use, when the gas generated inside the outer shell 21 of the battery cell 20 reaches a threshold, the one-way valve 30 can be opened, but the pressure relief mechanism 70 cannot be opened. Furthermore, in the event of thermal runaway, before opening the pressure relief mechanism 70, the one-way valve 30 can be destroyed at the weak zone 3119 to provide a certain degree of pressure relief. If the gas pressure inside the battery cell 20 continues to increase, the pressure relief mechanism 70 can be opened.

[0202] Please refer to Figure 22, which is a schematic diagram of the exploded structure of a battery cell 20 according to one or more embodiments. According to some embodiments of the present application, the battery cell 20 further includes a protective patch 60, which is disposed on the side of the end cap 21 facing the exterior of the housing. Specifically, the protective patch 60 is disposed on the outer surface 21a of the end cap 21 to provide a certain degree of protection for the end cap 21. The protective patch 60 can be made of a variety of materials, such as rubber, silicone, or plastic.

[0203] According to some embodiments of the present application, a first avoidance hole 601 penetrating the protective patch 60 is provided on the protective patch 60 , and the first avoidance hole 601 is used for the one-way valve 30 to pass through.

[0204] According to some embodiments of the present application, in an embodiment in which an electrode terminal 25 is provided on the end cap 21, as shown in FIG22 , a second avoidance hole 602 is provided on the protective patch 60 at a position corresponding to the electrode terminal 25. The second avoidance hole 602 runs through both sides of the protective patch 60. The second avoidance hole 602 is used to allow the electrode terminal 25 to pass through, avoiding the electrode terminal 25. Exemplarily, two electrode terminals 25 are provided on the end cap 21, and correspondingly, the protective patch 60 is provided with two second avoidance holes 602, each of which is used to allow one electrode terminal 25 to pass through.

[0205] In an embodiment in which a pressure relief mechanism 70 is provided on the end cover 21, as shown in Figure 22, a third avoidance hole 603 is provided at the position of the protective patch 60 corresponding to the pressure relief mechanism 70. The third avoidance hole 603 passes through both sides of the protective patch 60, and the positive projection of the pressure relief mechanism 70 on the protective patch 60 is located in the third avoidance hole 603, so that the third avoidance hole 603 can avoid the pressure relief mechanism 70.

[0206] According to some embodiments of the present application, the protective patch 60 is provided with an information collection hole (not shown) that passes through the protective patch 60. The information collection hole serves as a part of the exposed end cover 21, so as to facilitate setting an information code on the end cover 21 or connecting a detection element for sampling, etc.

[0207] According to some embodiments of the present application, the protective patch 60 may be provided on the end cover 21 in various structures, and the protective patch 60 may be provided on the end cover 21 by bonding, adsorption, or the like.

[0208] Continuing with FIG. 22 , according to some embodiments of the present application, the battery cell 20 further includes an insulating member 24 . The insulating member 24 is disposed on the side of the end cap 21 facing the interior of the housing; that is, an insulating member 24 may also be disposed on the inner side of the end cap 21 . The insulating member 24 can be used to isolate the electrical connection components within the housing 22 from the end cap 21 to reduce the risk of short circuits. Exemplarily, the insulating member 24 may be made of plastic, rubber, or the like.

[0209] The insulating member 24 is made of a material that will not contact the electrode assembly 23 inside the battery 100 to cause a short circuit. The insulating member 24 is used to protect the end cap 21 from being directly exposed to the electrode assembly 23 in the height direction to prevent contact with the electrode assembly 23 to cause a short circuit.

[0210] The insulating member 24 is provided with a second exhaust hole 292 that passes through the insulating member 24, so that the gas inside the battery 100 enters the area of ​​the one-way valve 30 through the first exhaust hole 291. Furthermore, the second exhaust hole 292 is connected to the first exhaust hole 291 to make exhaust smoother.

[0211] According to some embodiments of the present application, referring to FIG. 22 , the battery cell 20 further includes a pressure relief mechanism 70 , which is disposed on the housing and configured to actuate and release the internal pressure of the battery cell 20 when the battery cell 20 thermally runs away.

[0212] The pressure relief mechanism 70 is provided on the outer shell, and may be provided on the end cover 21 or on the shell 22 . For example, in FIG. 1 , the pressure relief mechanism 70 is provided on the end cover 21 .

[0213] The pressure relief mechanism 70 is configured to activate and release the internal pressure of the battery cell 20 when the battery cell 20 experiences thermal runaway. Specifically, when thermal runaway occurs within the battery cell 20, the pressure relief mechanism 70 can activate and open to release gases generated within the battery cell 20 due to thermal runaway. It should be noted that when thermal runaway occurs within the battery cell 20, the gas inside the outer casing of the battery cell 20 rapidly surges, causing the pressure relief mechanism 70 to open and release the pressure. However, during normal use, the gas generated within the outer casing of the battery cell 20 can be discharged through the one-way valve 30, but this does not allow the pressure relief mechanism 70 to open.

[0214] Optionally, the pressure relief mechanism 70 and the housing can be an integrally formed structure or a separately provided structure. If the pressure relief mechanism 70 and the housing are an integrally formed structure, the pressure relief mechanism 70 is an area on the housing where a weak structure is provided, for example, an area on the housing where a notched groove is provided. If the pressure relief mechanism 70 and the housing can be a separate structure, the pressure relief mechanism 70 can be connected to the housing by welding, hot melting, injection molding, or bonding. For example, in FIG15 , the pressure relief mechanism 70 and the housing are a separate structure, and the pressure relief mechanism 70 is provided on the end cover 21 of the housing. The pressure relief mechanism 70 can be a pressure relief component such as an explosion-proof valve, an explosion-proof disk, a pressure relief valve, or a safety valve.

[0215] For example, in Figure 1, the electrode terminal 25 and the pressure relief mechanism 70 are both arranged on the end cover 21. The battery cell 20 adopting this structure can save the space occupied by the battery cell 20. Of course, in other embodiments, the electrode terminal 25 and the pressure relief mechanism 70 can also be arranged on different walls of the outer shell. The battery cell 20 adopting this structure can make the electrode terminal 25 of the battery cell 20 used to output or input electrical energy and the pressure relief mechanism 70 used to release internal pressure stay away from each other to reduce the risk of using the battery cell 20. For example, the pressure relief mechanism 70 is arranged on the shell 22, and the electrode terminal 25 is arranged on the end cover 21.

[0216] By providing a one-way valve 30, when gas is generated inside the shell during normal use of the battery cell 20, it can be discharged to the outside of the shell through the one-way valve 30, thereby alleviating the phenomenon of premature actuation of the pressure relief mechanism 70 before the thermal runaway of the battery cell 20 due to the increase in internal air pressure of the battery cell 20, thereby effectively improving the use stability of the battery cell 20 and improving the service life and reliability of the battery cell 20.

[0217] In some embodiments, the one-way valve 30 and the pressure relief mechanism 70 may be disposed on the same wall of the housing. For example, the one-way valve 30 and the pressure relief mechanism 70 may both be disposed on the end cap 21. A battery cell 20 employing this structure can help conserve space within the battery cell 20 and thereby increase the energy density of the battery cell 20.

[0218] In some embodiments, the one-way valve 30 and the pressure relief mechanism 70 can be located on different walls of the housing. For example, the one-way valve 30 can be located on the housing 22, while the pressure relief mechanism 70 can be located on the end cap 21. A battery cell 20 employing this structure can reduce the interaction between the one-way valve 30 and the pressure relief mechanism 70 and adapt to different usage environments. Preferably, the one-way valve 30 and the pressure relief mechanism 70 are located on the top wall of the battery 100 when it is in a resting position to facilitate gas discharge.

[0219] In some embodiments, the actuation pressure of the pressure relief mechanism 70 is greater than the opening pressure of the one-way valve 30. That is, the pressure of the gas inside the housing to open the pressure relief mechanism 70 is greater than the pressure of the gas inside the housing to open the one-way valve 30. When a battery cell 20 experiences thermal runaway, the gas inside the housing of the battery cell 20 will rapidly surge, causing the pressure relief mechanism 70 to open and release pressure. However, during normal use of the battery cell 20, when the gas generated inside the housing 21 reaches a threshold, the one-way valve 30 can be opened, but the pressure relief mechanism 70 cannot be opened.

[0220] In some embodiments, the exhaust rate of the one-way valve 30 is less than the exhaust rate of the pressure relief mechanism 70 .

[0221] By setting the exhaust rate of the one-way valve 30 to be lower than the exhaust rate of the pressure relief mechanism 70, the phenomenon that the one-way valve 30 exhausts too quickly and the pressure relief mechanism 70 cannot be actuated to open can be alleviated when the battery cell 20 has thermal runaway. This allows the pressure relief mechanism 70 to actuate and stably discharge the internal pressure of the battery cell 20 when the battery cell 20 has thermal runaway, making it easier to relieve pressure, thereby helping to reduce the risk of fire and explosion of the battery cell 20 when the battery cell 20 has thermal runaway.

[0222] The end cap 21 is provided with a pressure relief hole 701, which is connected to the pressure relief mechanism 70. The diameter of the pressure relief hole 701 may be larger than the diameter of the first exhaust hole 291 connected to the one-way valve 30, so that the exhaust rate of the pressure relief mechanism 70 is greater than the exhaust rate of the one-way valve 30.

[0223] This allows the pressure relief mechanism 70 to be activated and opened, preventing the one-way valve 30 from venting too quickly and causing it to fail to open when the battery cell 20 experiences thermal runaway. This allows the pressure relief mechanism 70 to activate and stably release the internal pressure of the battery cell 20 when the battery cell 20 experiences thermal runaway, thereby reducing the risk of fire and explosion in the battery cell 20. The airtightness of the system is also taken into consideration to prevent excessive exhaust rates from causing a deterioration in the airtightness of the system. This ensures that the airtightness of the battery 100 system is maintained while the gas is discharged.

[0224] In some embodiments, the end cap 21 is provided with a liquid injection hole, and the first vent hole 291 for mounting the one-way valve 30 can also serve as the liquid injection hole. Specifically, after the battery cell 20 is fully injected, the one-way valve 30 is mounted on the liquid injection hole, replacing the original sealing structure of the liquid injection hole with the one-way valve 30. By configuring the first vent hole 291 for mounting the one-way valve 30 as the liquid injection hole, liquid can be injected into the housing through the first vent hole 291 before the one-way valve 30 is mounted in the first vent hole 29128. This eliminates the need for a separate liquid injection hole in the housing, improving the production efficiency of the battery cell 20 and reducing the manufacturing cost of the battery cell 20. Alternatively, the first vent hole 291 and the liquid injection hole can be spaced apart.

[0225] In some embodiments, the battery cell 20 is an alkali metal battery 100, such as a sodium metal battery 100, a lithium metal battery 100, or a magnesium metal battery 100. The alkali metal battery 100 is used in conjunction with a vent assembly to promptly exhaust gases generated by the alkali metal battery 100 during normal operation, thereby extending the service life of the alkali metal battery 100.

[0226] The electrode assembly 23 is mainly formed by winding or stacking positive and negative electrode sheets, and a separator is usually provided between the positive and negative electrode sheets. The parts of the positive and negative electrode sheets containing active materials constitute the main body of the electrode assembly 23, and the parts of the positive and negative electrode sheets without active materials each constitute the tabs. The positive and negative electrode tabs can be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery 100, the positive and negative electrode active materials react with the electrolyte, and the tabs are connected to the electrode terminals 25 to form a current circuit.

[0227] In one embodiment, the positive electrode sheet includes a positive electrode current collector and a positive electrode active layer disposed on at least one side of the positive electrode current collector, wherein the positive electrode active layer includes a positive electrode active material.

[0228] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active layer may be provided on either or both of the two facing surfaces of the positive electrode current collector.

[0229] In one embodiment, the positive electrode current collector may be a metal foil or a composite current collector. For example, aluminum foil may be used as the metal foil. The composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0230] In one embodiment, the positive electrode material includes one or more of a polyanion-based positive electrode material, a phosphate-based positive electrode material, a sulfate-based positive electrode material, a silicate-based positive electrode material, and a borate-based positive electrode material. For example, in the positive electrode active material of the sodium battery 100, the polyanion-based compound includes compounds based on phosphoric acid and fluorophosphate. Phosphate-based compounds include Nax1Fey1Pm1On1, for example, sodium iron phosphate with a higher capacity and sodium iron pyrophosphate with a higher voltage platform. The polyanion-based compound includes one or more of sodium vanadium trifluorophosphate Na3V2(PO4)2F3, sodium vanadium fluorophosphate NaVPO4F, sodium vanadium phosphate Na3V2(PO4)3, Na4Fe3(PO4)2P2O7, NaFePO4, and Na3V2(PO4)3. The Prussian blue compound is NaxMM(CN)6, where M and M are one or more of Fe, Mn, Co, Ni, Cu, Zn, Cr, Ti, V, Zr, and Ce, and 0 < x ≤ 2. The positive electrode active material in the lithium metal battery 100 may include at least one of lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium iron phosphate, lithium cobalt oxide, lithium manganese oxide, or lithium iron manganese phosphate.

[0231] In one embodiment, the negative electrode sheet includes a negative electrode current collector and a negative electrode active layer disposed on at least one surface of the negative electrode current collector. The negative electrode active layer includes a negative electrode active material. In this embodiment, the battery cell 20 is an ion battery 100. During the charge and discharge process of the battery 100, active ions (such as Li+ and Na+) are intercalated and deintercalated in the negative electrode active material.

[0232] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active layer may be disposed on either or both of the two facing surfaces of the negative electrode current collector.

[0233] In one embodiment, the negative electrode current collector may be a metal foil or a composite current collector. For example, copper foil may be used as the metal foil. The composite current collector may include a polymer base layer and a metal layer formed on at least one surface of the polymer base material. The composite current collector may be obtained by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer base material (such as a base material of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0234] In one embodiment, the negative electrode active material may include one or more of a silicon-based material, a silicon-carbon material, a carbon material, and a selenium-based material. Specifically, it includes one or more of artificial graphite, natural graphite, hard carbon, soft carbon, a silicon-based material, and a selenium-based material. The silicon-based material may be selected from one or more of elemental silicon, a silicon oxide (e.g., silicon 2 oxide), a silicon-carbon composite, a silicon-nitrogen composite, and a silicon alloy. The selenium-based material may be selected from one or more of elemental selenium, a selenium oxide, and a selenium alloy.

[0235] In one embodiment, the negative electrode plate includes a negative electrode current collector and a carbon-containing coating provided on at least one surface of the negative electrode current collector. In this embodiment, the battery cell 20 is a metal battery 100, and during the charge and discharge process of the battery 100, active ions are deposited / stripped at the negative electrode plate. The metal battery 100 can be an alkali metal battery 100, such as a lithium metal battery 100, a sodium metal battery 100, a potassium metal battery 100, a zinc metal battery 100, or an aluminum metal battery 100. This type of battery 100 can also be called a "negative electrode-free battery 100". During the charging process, sodium metal is formed by depositing active ions (such as Na+) released from the positive electrode active material onto the negative electrode current collector. The provision of the carbon-containing coating facilitates more uniform metal deposition. The carbon-containing material includes one or more of conductive carbon, graphite, hard carbon, and carbon nanotubes.

[0236] In other embodiments, a conductive film layer may be deposited on the negative electrode current collector. Examples include alloy materials, titanium-based materials, active metals (e.g., sodium metal), carbon-based materials deposited with metals, composite materials containing metals, and alloy materials containing metals. Such alloy materials include, but are not limited to, sodium-tin alloys, sodium-germanium alloys, and sodium-antimony alloys. Such titanium-based materials include, but are not limited to, titanium dioxide, titanates, and titanium phosphates.

[0237] In one embodiment, the positive electrode active layer and the negative electrode active layer may further include a binder and a conductive agent. As an example, the binder may include polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer and at least one of a fluorine-containing acrylate resin. As an example, the conductive agent may include at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.

[0238] In one embodiment, the isolation membrane can be any known porous structure isolation membrane with good chemical stability and mechanical stability.

[0239] In one embodiment, the material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation.

[0240] The electrolyte conducts ions between the positive and negative electrodes. The electrolyte can be liquid, gel, or solid.

[0241] In some embodiments, the electrolyte is an electrolyte solution. The electrolyte solution includes an electrolyte salt and a solvent. The electrolyte salt dissolves to form electrolyte ions, and conduction is achieved through the movement of the electrolyte ions in the electrolyte salt.

[0242] In one embodiment, the electrolyte salt in the sodium battery 100 includes sodium salts such as sodium hexafluorophosphate (NaPF6), sodium bis(fluorosulfonyl)imide (NaFSI), sodium trifluoromethanesulfonate (CF3NaO3S), and sodium sulfide (Na2S). The lithium battery 100 includes at least one lithium salt selected from the group consisting of lithium perchlorate, lithium hexafluoroarsenate, lithium hexafluorophosphate, lithium bis(trifluoromethylsulfonyl)imide, lithium bis(fluorosulfonyl)imide, lithium difluorooxalatoborate, lithium tetrafluoroborate, and lithium trifluoromethanesulfonate.

[0243] In one embodiment, the solvent includes one or more solvents selected from the group consisting of chain ethers, ethylene glycol dimethyl ether and its derivatives, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, and cyclic ethers, specifically including dimethyl ether (DME), diethylene glycol diethyl ether, tetraethylene glycol dimethyl ether, 2,2,2,2-trifluoroethyl ether, ethylene glycol diethyl ether, triethylene glycol dimethyl ether, ethylene glycol dimethyl ether derivatives, trifluoroethyl methyl carbonate (FEMC), dioxolane (DOL), acetonitrile (AN), fluorobenzene, triethyl phosphate (TEP), sulfolane, 2-methyltetrahydrofuran, tetrahydrofuran, dimethyl sulfoxide, N,N-dimethylacetamide, and the like.

[0244] In one embodiment, the electrolyte may further include additives. For example, the additives may include negative electrode film-forming additives, positive electrode film-forming additives, and additives capable of improving certain properties of the battery 100, such as additives that improve the overcharge performance of the battery 100, and additives that improve the high or low temperature performance of the battery 100.

[0245] According to some embodiments of the present application, a battery 100 is provided, comprising a battery cell 20 according to any of the above-described embodiments. Please refer to FIG. 23 , which is a schematic diagram of an exploded structure of the battery 100 according to one or more embodiments. The battery 100 comprises a housing 10 and a battery cell 20, with the battery cell 20 contained within the housing 10. The housing 10 is configured to provide a storage space for the battery cell 20 and can have various structures. In some embodiments, the housing 10 can include a first portion 11 and a second portion 12, which overlap with each other and together define a storage space for the battery cell 20. The second portion 12 can be a hollow structure with one end open, and the first portion 11 can be a plate-like structure, overlapping the open side of the second portion 12, so that the first portion 11 and the second portion 12 together define a storage space. Alternatively, the first portion 11 and the second portion 12 can each be a hollow structure with one end open, with the open side of the first portion 11 overlapping the open side of the second portion 12. Of course, the box body 10 formed by the first part 11 and the second part 12 can be in various shapes, such as a cylinder, a cuboid, etc.

[0246] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 20. The multiple battery cells 20 may be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery 100 may be housed within the housing 10. Of course, the battery 100 may also be in the form of a battery module 100, in which multiple battery cells 20 are first connected in series, in parallel, or in a hybrid connection, and then the multiple battery modules 100 are further connected in series, in parallel, or in a hybrid connection to form an entire battery 100, and then housed within the housing 10. The battery 100 may also include other structures, for example, the battery 100 may also include a busbar component for electrically connecting the multiple battery cells 20.

[0247] Each battery cell 20 may be a secondary battery 100 or a primary battery 100; specific examples include all types of primary batteries 100 or secondary batteries 100. For example, it may be a lithium battery 100, a sodium battery 100, a potassium battery 100, or other types of secondary batteries 100. A lithium secondary battery 100 may include a lithium metal secondary battery 100, a lithium ion secondary battery 100, a lithium polymer secondary battery 100, or a lithium ion polymer secondary battery 100. Alternatively, it may be a lithium sulfur battery 100, a sodium ion battery 100, or a magnesium ion battery 100, but is not limited thereto. The battery cell 20 may be cylindrical, flat, rectangular, or have other shapes.

[0248] In some embodiments, the battery 100 may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0249] According to some embodiments of the present application, the present application further provides an electric device, which includes a battery cell 20 according to any of the above solutions, and the battery cell 20 is used to provide power to the electric device. The electric device can be any of the above devices or systems using the battery cell 20.

[0250] In some embodiments, the purpose of the electric equipment of the present application is not particularly limited, and it can be used for any electronic device known in the prior art. The battery 100 disclosed in the embodiment of the present application can be used for electric equipment using the battery 100 as a power source or various energy storage systems using the battery 100 as an energy storage element. That is, a kind of electric equipment is provided. In some embodiments, the electric equipment of the present application can be used for, but not limited to, laptop computers, pen-input computers, mobile computers, e-book players, portable phones, portable fax machines, portable copiers, portable printers, head-mounted stereo headphones, video recorders, LCD TVs, portable cleaners, portable CD players, mini discs, transceivers, electronic notepads, calculators, memory cards, portable recorders, radios, backup power supplies, motors, cars, motorcycles, power bicycles, bicycles, ships, spacecraft, lighting fixtures, toys, game consoles, clocks, power tools, flashlights, cameras, large-scale household batteries 100 and lithium-ion capacitors, etc.

[0251] The electric device can select a battery cell 20, a battery 100 module or a battery 100 pack according to its usage requirements.

[0252] Please refer to Figure 24, which is a schematic structural diagram of a vehicle 1000 according to one or more embodiments. The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 can be provided at the bottom, head or tail of the vehicle 1000. The battery 100 can be used to power the vehicle 1000. For example, the battery 100 can serve as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0253] In some embodiments of the present application, the battery 100 can serve not only as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0254] In the above embodiment, by providing a one-way valve 30, the gas inside the battery 100 housing can be promptly discharged to the outside of the housing, so that the air pressure inside the battery 100 housing does not become too high, reducing the risk of the pressure relief mechanism 70 opening the valve prematurely, and significantly improving the life of the battery 100. One or more one-way valves 30 can be provided on a battery cell 20, and the location and manner of each one-way valve 30 can be different. For example, one one-way valve 30 can be provided on the side of the end cap 21 facing the inside of the battery 100 housing, and one one-way valve 30 can be provided on the side of the end cap 21 facing the outside of the battery 100 housing. One one-way valve 30 can be provided on the end cap 21, and the other one-way valve 30 can be provided on the housing 22.

[0255] The above description is only an implementation method of the present application and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the description and drawings of this application, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A battery cell, characterized in that, it includes: a housing having a wall portion, the wall portion having a first exhaust hole, and the first exhaust hole communicating the interior of the housing with the exterior of the housing; a one-way valve including a valve body and a valve core, the valve body having a valve cavity inside, the valve body being provided with an air inlet and an air outlet, the air inlet communicating the valve cavity with the interior of the housing, and the air outlet communicating the valve cavity with the exterior of the housing; the valve core is disposed in the valve cavity, the valve core is used to block the air inlet, and the valve core is configured to open the air inlet under the action of the gas inside the housing and release the gas inside the battery cell; the wall portion has an outer surface and an inner surface arranged opposite to each other, the outer surface faces the exterior of the housing, and the inner surface faces the interior of the housing; the valve body is disposed on the outer surface, and at least a part of the valve body protrudes from the outer surface.

2. The battery cell according to claim 1, characterized in that, the valve body includes: a valve seat; a valve cover including a cover top wall and a cover side wall connected to the cover top wall, the cover top wall, the cover side wall and the valve seat enclosing to form the valve cavity, the valve seat being provided with the air inlet of the valve cavity, and the valve cover being provided with the air outlet; the valve seat has a first through hole penetrating the valve seat, and the air inlet is the first through hole.

3. The battery cell according to claim 2, characterized in that, the cover side wall has a second through hole penetrating the cover side wall, and the air outlet is the second through hole.

4. The battery cell according to claim 3, characterized in that, along the direction away from the cover top wall, the second through hole extends to the end of the cover side wall; optionally, there are a plurality of the second through holes, and the plurality of the second through holes are spaced apart in the circumferential direction of the cover side wall.

5. The battery cell according to any one of claims 2 to 4, characterized in that, a first guiding post protrudes from the side of the cover top wall facing the valve cavity, and the cover top wall has a third through hole penetrating the cover top wall and the first guiding post; or the cover top wall has a third through hole penetrating the cover top wall, and the air outlet is the third through hole.

6. The battery cell according to any one of claims 2 to 5, characterized in that, the valve cover further includes a flanging wall, the cover side wall connects the cover top wall and the flanging wall, the flanging wall extends away from the valve cavity relative to the cover side wall, and the flanging wall is connected to the valve seat.

7. The battery cell according to claim 6, characterized in that, a first sinking groove recessed relative to the surface of the valve seat is provided on the side of the valve seat facing the valve cover, and at least a part of the flanging wall is received in the first sinking groove and connected to the valve seat.

8. The battery cell according to claim 7, characterized in that, a first step surface and a second step surface are provided on the side of the valve seat facing the valve cover, the first step surface is closer to the valve cover than the second step surface, and the first sinking groove is provided on the first step surface.

9. The battery cell according to claim 7 or 8, characterized in that, The surface of the flanging wall facing the cover top wall is flush with the surface of the valve seat facing the valve cover; or the surface of the flanging wall facing the cover top wall is lower than the surface of the valve seat facing the valve cover.

10. The battery cell according to any one of claims 7 to 9, wherein, the flanging wall is welded to the valve seat; wherein, in the circumferential direction of the cover side wall, at least a part of the first weld mark between the flanging wall and the valve seat is offset from the second through hole on the cover side wall.

11. The battery cell according to claim 6, wherein, a connecting protrusion protrudes from the outer peripheral surface of the valve seat, a receiving groove is provided on the inner peripheral surface of the flanging wall, and the connecting protrusion is received in the receiving groove and connected to the flanging wall.

12. The battery cell according to claim 11, wherein, the connecting protrusion is welded to the flanging wall, wherein the flanging wall has an upper surface and a lower surface arranged opposite to each other, the upper surface faces the cover top wall, and the second weld mark of the connection between the connecting protrusion and the flanging wall is located on the lower surface of the flanging wall.

13. The battery cell according to claim 1, wherein, the valve body includes a valve cover, the valve cover includes a cover top wall and a cover side wall connected to the cover top wall, the cover top wall, the cover side wall and the wall portion enclose to form the valve cavity, the first exhaust hole is the air inlet of the valve cavity, and an air outlet of the valve cavity is provided on the valve cover.

14. The battery cell according to claim 13, wherein, a second sinking groove recessed relative to the outer surface of the wall portion is provided on the side of the wall portion facing the outside of the housing, the valve cover further includes a flanging wall, the cover side wall connects the cover top wall and the flanging wall, the flanging wall extends away from the valve cavity relative to the cover side wall, and at least a part of the flanging wall is received in the second sinking groove and connected to the wall portion.

15. The battery cell according to any one of claims 1 to 14, wherein, the valve core includes: an elastic member disposed in the valve cavity; a plugging member movably disposed in the valve cavity, the plugging member is used to plug the air inlet under the action of the elastic member, and is used to open the air inlet under the action of the gas inside the housing.

16. The battery cell according to claim 15, wherein, the valve body includes a valve cover, a first guiding post protrudes from the side of the valve cover facing the plugging member, and a part of the elastic member is sleeved outside the first guiding post.

17. The battery cell according to claim 16, wherein, the diameter of the first guiding post is D1, the inner diameter of the elastic member is D2, and 0mm < D2 - D1 ≤ 5mm is satisfied.

18. The battery cell according to claim 16 or 17, wherein, a second guiding post protrudes from the side of the plugging member facing the valve cover, and a part of the elastic member is sleeved outside the second guiding post.

19. The battery cell according to claim 18, wherein, The diameter of the second guiding post is D3, and the inner diameter of the elastic member is D2, satisfying 0mm < D3 - D1 ≤ 5mm.

20. The battery cell according to claim 18 or 19, characterized in that axially of the elastic member, there is a gap between the end face of the first guiding post on the side away from the valve cover and the end face of the second guiding post on the side close to the valve cover; Optionally, the height H1 of the gap satisfies 0mm < H1 ≤ 0.5mm.

21. The battery cell according to any one of claims 15 to 20, characterized in that axially of the valve cavity, both ends of the elastic member respectively abut against the valve cover and the plugging member, the distance between the first abutting surface of the valve cover and the second abutting surface of the plugging member is L1, and the solid length of the elastic member is L2, where L1 > L2; wherein, the solid length of the elastic member is the length occupied by the solid of the elastic member after being completely compressed; Optionally, L1 - L2 > 0.5mm.

22. The battery cell according to claim 21, characterized in that the elastic member is a spring, and the solid length L2 of the elastic member = d1*n1 + d2 + d3, where d1 is the wire diameter of the spring, n1 is the maximum number of turns of the spring axially, d2 is the thickness of the outermost spring at one end of the spring, d3 is the thickness of the outermost spring at the other end of the spring, d2 ≤ d1, d3 ≤ d1.

23. The battery cell according to any one of claims 15 to 22, characterized in that the elastic member is a spring, and the material of the elastic member includes steel, iron or aluminum.

24. The battery cell according to any one of claims 15 to 23, characterized in that a plurality of limiting protrusions are convexly provided on the outer peripheral surface of the plugging member, and the plurality of limiting protrusions are arranged at intervals along the circumferential direction of the plugging member.

25. The battery cell according to any one of claims 15 to 24, characterized in that the plugging member includes a pressing part and a sealing part, both ends of the elastic member respectively abut against the valve cover and the pressing part, the sealing part is connected to the side of the pressing part away from the valve cover, and the sealing part is used to plug the air inlet.

26. The battery cell according to any one of claims 15 to 25, characterized in that the material of the sealing part includes ethylene propylene diene monomer, fluororubber or polytetrafluoroethylene.

27. The battery cell according to any one of claims 1 to 26, characterized in that the valve cover includes a cover side wall, and a second through hole penetrating the cover side wall is provided on the cover side wall, the air outlet is the second through hole, and along the axis direction of the valve cavity, the sealing interface between the valve core and the valve seat is higher than or flush with the bottom wall of the second through hole.

28. The battery cell according to any one of claims 1 - 12, 15 - 27, characterized in that the one-way valve is at least partially received in the first exhaust hole.

29. The battery cell according to claim 28, characterized in that The first exhaust hole includes a through-hole section and a first hole section. The through-hole section and the first hole section are arranged along the thickness direction of the wall portion. The first hole section is located on the side of the through-hole section facing away from the interior of the housing. The aperture of the first hole section is larger than that of the through-hole section. The one-way valve is at least partially received in the first hole section.

30. The battery cell according to claim 29, wherein, the first hole section includes a circumferentially arranged hole side surface, and the outer peripheral surface of the valve cover / valve seat of the one-way valve is welded to the hole side surface.

31. The battery cell according to claim 29 or 30, wherein, a first step surface and a second step surface are provided on the side of the valve seat facing the valve cover. The first step surface is closer to the valve cover than the second step surface. The outer peripheral surface of the second step is welded to the hole side surface.

32. The battery cell according to claim 30 or 31, wherein, the hole side surface fits with the outer peripheral surface of the valve cover / valve seat of the one-way valve, and both the hole side wall surface and the outer peripheral surface of the valve cover / valve seat of the one-way valve are arranged at an acute angle to the central axis of the first exhaust hole.

33. The battery cell according to any one of claims 30 to 32, wherein, a stress relief groove is provided around the welding mark of the valve cover / valve seat and the wall portion; Optionally, a first stress relief groove is provided on the surface of the valve seat / valve cover facing the outside of the housing; and / or a second stress relief groove is provided on the surface of the wall portion facing the outside of the housing.

34. The battery cell according to any one of claims 1 to 33, wherein, a strength weak area is provided on the valve body.

35. The battery cell according to claim 34, wherein, the strength weak area includes a thickness weak area.

36. The battery cell according to claim 35, wherein, the valve body includes a valve cover. The valve cover includes a cover top wall and a cover side wall connected to the cover top wall. The thickness weak area includes a groove provided on the cover side wall.

37. The battery cell according to claim 36, wherein, a second through-hole penetrating the cover side wall is provided on the cover side wall, and the groove is provided on the connecting arm between two adjacent second through-holes.

38. The battery cell according to claim 36 or 37, wherein, the groove is located on the side of the cover side wall facing the valve cavity; or the groove is located on the side of the cover side wall away from the valve cavity.

39. The battery cell according to any one of claims 36 to 38, wherein, the thickness weak area includes a first scoring groove, and the first scoring groove is a circumferential groove on the cover side wall.

40. The battery cell according to any one of claims 36 to 38, wherein, the thickness weak area includes a plurality of second scoring grooves, and the plurality of second scoring grooves are arranged at intervals in the circumferential direction of the cover side wall.

41. The battery cell according to any one of claims 1 to 40, wherein, the battery cell further includes: An insulating member is disposed on the side of the wall portion facing the interior of the housing; a second exhaust hole penetrating the insulating member is provided on the insulating member, and the second exhaust hole communicates with the first exhaust hole on the wall portion.

42. The battery cell according to any one of claims 1 to 41, wherein, the first exhaust hole is the liquid injection hole of the battery cell; or the first exhaust hole is spaced apart from the liquid injection hole of the battery cell.

43. The battery cell according to any one of claims 1 to 42, wherein, the housing includes: a housing body, an accommodating cavity with an opening is formed inside, and the accommodating cavity is used to accommodate the electrode assembly; an end cap for closing the opening; wherein, the end cap is the wall portion; or the housing body includes the wall portion; or the wall portion is the wall at the top of the housing when the battery cell is in the placed state.

44. The battery cell according to any one of claims 1 to 43, wherein, the battery cell further includes: a pressure relief mechanism disposed on the housing, and the pressure relief mechanism is configured to actuate and release the internal pressure of the battery cell when the battery cell is in thermal runaway, and the actuation pressure of the pressure relief mechanism is greater than the opening pressure of the one-way valve.

45. The battery cell according to claim 44, wherein, the wall portion has a pressure relief hole, the pressure relief hole communicates the interior of the housing with the exterior of the housing, and the pressure relief mechanism is disposed in the pressure relief hole; the aperture of the pressure relief hole is greater than the aperture of the first exhaust hole.

46. The battery cell according to claim 44 or 45, wherein, the exhaust rate of the one-way valve is less than the exhaust rate of the pressure relief mechanism.

47. The battery cell according to any one of claims 1 to 46, wherein, the opening pressure of the one-way valve is greater than or equal to 0.2 MPa; optionally, greater than or equal to 0.4 MPa.

48. The battery cell according to any one of claims 44 to 47, wherein, a strength weak area is provided on the valve body, the actuation pressure of the pressure relief mechanism is greater than the actuation pressure of the strength weak area, and the actuation pressure of the strength weak area is greater than the opening pressure of the one-way valve.

49. The battery cell according to any one of claims 1 to 48, wherein, the aperture of the air inlet is greater than or equal to the aperture of the first exhaust hole.

50. A battery, wherein, it includes the battery cell according to any one of claims 1 - 49.

51. An electrical device, wherein, it includes the battery cell according to any one of claims 1 - 49, and the battery cell is used to provide electrical energy.

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