Battery monomer, battery and electric device

Abstract

The utility model is applicable to the technical field of batteries, and provides a single battery, a battery and a power utilization device, the power utilization device comprises the battery, the battery comprises the single battery, the single battery comprises a shell assembly, an electrode assembly and a fire extinguishing structure, and the electrode assembly is arranged in the shell assembly. A weld joint is formed in the shell assembly, and at least one fire extinguishing structure is arranged at the weld joint; and / or the shell assembly is provided with a pressure relief mechanism, and at least one fire extinguishing structure is arranged at the pressure relief mechanism. The single battery is arranged to comprise the fire extinguishing structure, and the fire extinguishing structure is arranged on at least one of the weld joint and the pressure relief mechanism of the shell assembly, so that the fire extinguishing structure can perform cooling and fire extinguishing work on at least one of the weld joint and the pressure relief mechanism. Therefore, the problems of thermal runaway reaction and thermal spread of the battery monomers can be improved, so that the problem of chain reaction of thermal runaway of adjacent battery monomers can be improved, the problem of thermal runaway of the whole battery is improved, and the reliability of the battery is improved.

Description

Technical Field

[0001] This application belongs to the technical field of batteries, and more specifically, relates to a battery cell, a battery, and an electrical device. Background Art

[0002] In the related art, during the thermal runaway process of a battery cell, it is inevitable to rapidly generate high temperatures, thereby generating high-temperature and high-pressure gases and flames, causing the battery cell to undergo thermal runaway. The high-temperature and high-pressure gases and flames are prone to thermal spread to adjacent battery cells, resulting in a chain reaction of thermal runaway in adjacent battery cells, and further leading to thermal runaway of the entire battery. Summary of the Utility Model

[0003] In view of the above problems, the embodiments of this application provide a battery cell, a battery, and an electrical device, which can improve the technical problem of thermal runaway of the battery cell.

[0004] In a first aspect, the embodiments of this application provide a battery cell, including:

[0005] A housing assembly;

[0006] An electrode assembly, disposed within the housing assembly;

[0007] A fire extinguishing structure;

[0008] Wherein, the housing assembly forms a weld seam, and at least one fire extinguishing structure is disposed at the weld seam; and / or, the housing assembly is provided with a pressure relief mechanism, and at least one fire extinguishing structure is disposed at the pressure relief mechanism.

[0009] For the battery cell provided by the embodiments of this application, by setting the battery cell to include a fire extinguishing structure, and at least one of the weld seam and the pressure relief mechanism of the housing assembly is provided with a fire extinguishing structure, the fire extinguishing structure can perform temperature reduction and fire extinguishing work at least at one of the weld seam and the pressure relief mechanism of the housing assembly. In this way, the thermal runaway reaction and thermal spread problems of the battery cell can be improved, thereby improving the problem of the chain reaction of thermal runaway occurring in adjacent battery cells, improving the problem of thermal runaway of the entire battery, and improving the reliability of the battery.

[0010] In some embodiments, at least one fire extinguishing structure disposed at the weld seam abuts against the housing assembly;

[0011] and / or, at least one fire extinguishing structure disposed at the pressure relief mechanism abuts against the housing assembly;

[0012] and / or, the battery cell further includes an insulating structure disposed between the housing assembly and the electrode assembly, and at least one fire extinguishing structure disposed at the weld seam is disposed on the insulating structure;

[0013] And / or, the battery cell further includes an insulating structure disposed between the housing assembly and the electrode assembly, and at least one fire extinguishing structure disposed at the pressure relief mechanism is disposed on the insulating structure.

[0014] By adopting the above technical solution, the fire extinguishing structure can be attached to the housing assembly or disposed on the insulating structure within the housing assembly to cool and extinguish at least one of the weld seams and the pressure relief mechanism, thereby making the arrangement of the fire extinguishing structure very flexible.

[0015] In some embodiments, the housing assembly includes a housing and an end cap. The end cap is disposed on the housing and encloses with the housing to form a space for accommodating the electrode assembly.

[0016] A first weld seam is formed between the housing and the end cap. The weld seam includes the first weld seam, and at least one fire extinguishing structure is disposed at the first weld seam; and / or, the housing forms a second weld seam. The weld seam includes the second weld seam, and at least one fire extinguishing structure is disposed at the second weld seam.

[0017] In this way, the types and positions of the weld seams can be various, and cooling and extinguishing can be achieved through the fire extinguishing structure.

[0018] In some embodiments, the end cap is disposed at an end of the housing along a first direction.

[0019] At least one fire extinguishing structure disposed at the first weld seam is a first fire extinguishing member. The first fire extinguishing member is attached to the outer wall of the housing assembly along the first direction, and on a projection plane perpendicular to the first direction, along the width direction of the first weld seam, the distance between the outer edge of the housing assembly and the first fire extinguishing member is ≤6 mm; and / or, at least one fire extinguishing structure disposed at the first weld seam is a second fire extinguishing member. The second fire extinguishing member is attached to the outer wall of the housing assembly along a direction perpendicular to the first direction, and along the first direction, the distance between the outer edge of the housing assembly and the second fire extinguishing member is ≤6 mm.

[0020] With such a setting, at least one fire extinguishing structure can be attached to the outer wall of the housing assembly and disposed at the first weld seam, so that cooling and extinguishing operations can be performed at the first weld seam to improve the thermal runaway reaction and thermal propagation of the battery cell, thereby improving the thermal runaway of the battery and enhancing the reliability of the battery.

[0021] In some embodiments, at least one fire extinguishing structure disposed at the weld seam is attached to the surface of the weld seam.

[0022] By adopting the above technical solution, the fire extinguishing structure is attached to the surface of the weld seam, so that the cooling and extinguishing effect of the fire extinguishing structure on the weld seam can be improved, thereby better improving the thermal runaway and thermal propagation problems of the battery cell and enhancing the reliability of the battery.

[0023] In some embodiments, the battery cell further includes an insulating structure disposed between the housing assembly and the electrode assembly, and the insulating structure is disposed between the electrode assembly and the weld; on the path from the electrode assembly towards the weld, at least one fire extinguishing structure disposed at the weld is disposed between the insulating structure and the housing assembly.

[0024] With such an arrangement, the high-temperature and high-pressure gas and flame generated by the electrode assembly will pass through at least one fire extinguishing structure between the insulating structure and the housing assembly on the path towards the weld, so that at least one fire extinguishing structure can cool down and extinguish the high-temperature and high-pressure gas and flame on the path from the electrode assembly to the weld, thereby reducing the temperature of the high-temperature and high-pressure gas ejected from the weld and extinguishing the flame ejected from the weld, so as to improve the thermal runaway reaction and thermal propagation of the battery cell, and thus improve the thermal runaway of the battery and enhance the reliability of the battery.

[0025] In some embodiments, on the path from the electrode assembly towards the weld, at least one fire extinguishing structure disposed between the insulating structure and the housing assembly is a third fire extinguishing member; in a direction perpendicular to the distribution direction of the electrode assembly and the insulating structure, the third fire extinguishing member is disposed between the insulating structure and the housing assembly.

[0026] With such an arrangement, the third fire extinguishing member can be disposed between the insulating structure and the housing assembly on the path from the electrode assembly to the weld, so as to effectively cool down and extinguish the high-temperature and high-pressure gas and flame on the path from the electrode assembly to the weld, thereby reducing the temperature of the high-temperature and high-pressure gas ejected from the weld and extinguishing the flame ejected from the weld, so as to improve the thermal runaway reaction and thermal propagation of the battery cell, and thus improve the thermal runaway of the battery and enhance the reliability of the battery.

[0027] In some embodiments, the housing assembly is provided with a pressure relief mechanism spaced from the weld; on the path from the electrode assembly towards the weld, at least one fire extinguishing structure disposed between the insulating structure and the housing assembly is a fourth fire extinguishing member; the fourth fire extinguishing member is disposed between the housing assembly and the insulating structure and between the pressure relief mechanism and the weld.

[0028] By disposing the fourth fire extinguishing member between the housing assembly and the insulating structure and between the pressure relief mechanism and the weld, when the high-temperature and high-pressure gas and flame generated inside the battery cell are released to the pressure relief mechanism through the insulating structure, and the overflowing high-temperature and high-pressure gas and flame spread towards the weld, the fourth fire extinguishing member can cool down and extinguish the high-temperature and high-pressure gas and flame, thereby helping to reduce the temperature of the high-temperature and high-pressure gas released from the weld and extinguish the flame released from the weld, improving the thermal runaway and thermal propagation of the battery cell, so as to enhance the reliability of the battery.

[0029] In some embodiments, the housing assembly includes a housing and an end cap. The end cap is disposed at an end of the housing along a first direction to enclose a space for accommodating the electrode assembly with the housing; a first weld seam is formed between the housing and the end cap, and the weld seam includes a first weld seam; the end cap is provided with a pressure relief mechanism; in the first direction, an insulating structure is disposed between the end cap and the electrode assembly; a fourth fire extinguishing member is disposed between the end cap and the insulating structure along the first direction and is disposed between the pressure relief mechanism and the housing along a direction perpendicular to the first direction.

[0030] By adopting the above technical solution, for the high-temperature and high-pressure gas and flame generated by the electrode assembly and released from the insulating structure to the pressure relief mechanism, during the process of being released to the weld seam, the fourth fire extinguishing member can perform targeted temperature reduction and fire extinguishing operations, thereby improving the thermal runaway and thermal propagation of the battery cell and enhancing the reliability of the battery.

[0031] In some embodiments, the insulating structure is provided with a groove, and at least one fire extinguishing structure disposed between the insulating structure and the housing assembly is disposed in the groove on the path of the electrode assembly pointing to the weld seam.

[0032] With such a setting, at least part of the fire extinguishing structure can effectively achieve the function of temperature reduction and fire extinguishing within the housing assembly without increasing the size of the battery cell. In addition, the setting of the groove can also play a certain limiting role on the fourth fire extinguishing member, to a certain extent ensuring the temperature reduction and fire extinguishing effect of the fourth fire extinguishing member on the weld seam.

[0033] In some embodiments, the housing assembly includes a first wall and a pressure relief mechanism. The pressure relief mechanism includes a pressure relief portion, the first wall is connected to the outer periphery of the pressure relief portion, and at least one fire extinguishing structure is disposed at the pressure relief portion.

[0034] By disposing at least one fire extinguishing structure at the pressure relief portion, the fire extinguishing structure can perform temperature reduction and fire extinguishing on the pressure relief portion. In this way, the temperature of the high-temperature and high-pressure gas ejected from the pressure relief portion can be reduced, and the flame ejected from the pressure relief portion can be extinguished. That is, at least one fire extinguishing structure is disposed at the pressure relief portion to perform temperature reduction and fire extinguishing on the high-temperature and high-pressure gas and flame ejected from the pressure relief portion, thereby improving the thermal runaway reaction and thermal propagation of the battery cell and enhancing the reliability of the battery.

[0035] In some embodiments, the pressure relief portion is separately provided on the first wall;

[0036] Alternatively, the pressure relief portion is integrally provided on the first wall, and a first breakable mark is provided between the first wall and the pressure relief portion;

[0037] Alternatively, the pressure relief mechanism further includes a connecting portion connected to the first wall, and the pressure relief portion is separately provided on the connecting portion;

[0038] Alternatively, the pressure relief mechanism further includes a connecting portion connected to the first wall, the pressure relief portion is integrally arranged on the connecting portion, and a second easy-breaking mark is provided between the pressure relief portion and the connecting portion.

[0039] Such an arrangement allows for a variety of pressure relief mechanisms, making the design very flexible.

[0040] In some embodiments, at least one fire extinguishing structure disposed at the pressure relief portion is a fifth fire extinguishing member, the fifth fire extinguishing member is provided with a first through hole, and the pressure relief portion is opposite to the first through hole and exposed to the first through hole.

[0041] By adopting the above technical solution, during the thermal runaway of the battery cell, the high-temperature and high-pressure gas and flame generated by the battery cell can break through the pressure relief part of the pressure relief mechanism to be discharged from the battery cell through the pressure relief part, and the fifth fire extinguishing part provided at the pressure relief part can cool down and extinguish the high-temperature and high-pressure gas and flame. In addition, during the process of the high-temperature and high-pressure gas and flame breaking through the pressure relief part, they can also pass through the first through hole, thereby improving the problem of the fifth fire extinguishing part blocking the high-temperature and high-pressure gas and flame, and facilitating the release of the high-temperature and high-pressure gas and flame. Therefore, the thermal runaway reaction and heat spread problems of the battery cell can be improved, thereby improving the thermal runaway of the battery and improving the reliability of the battery.

[0042] In some embodiments, in a direction perpendicular to the through direction of the first through hole, the size of the fifth fire extinguishing component is larger than the size of the pressure relief portion, and the ratio of the size of the first through hole to the size of the pressure relief portion is ≥0.8 and ≤1.2.

[0043] Thus, on the one hand, the first through hole can effectively pass the high temperature and high pressure gas and flame without affecting the exhaust of the pressure relief mechanism. On the other hand, the fifth fire extinguishing element can effectively contact the high temperature and high pressure gas and flame to fully cool down and extinguish the fire.

[0044] In some embodiments, at least one fire extinguishing structure provided at the pressure relief portion is a sixth fire extinguishing component, which includes a first fire extinguishing component and a second fire extinguishing component connected to the outer periphery of the first fire extinguishing component, and the first fire extinguishing component is used to move relative to the second fire extinguishing component to relieve pressure; along the distribution direction of the first wall and the electrode assembly, the first fire extinguishing component and the pressure relief portion are arranged opposite to each other.

[0045] In this way, during the thermal runaway of the battery cell, the high-temperature and high-pressure gas and flame generated inside the battery cell can break through the pressure relief part and the first fire extinguishing part, thereby achieving pressure relief. In addition, the second fire extinguishing part and the first fire extinguishing part can cool down and extinguish the high-temperature and high-pressure gas and flame, and help exhaust gas, which can improve the thermal runaway reaction and heat spread of the battery cell, thereby improving the thermal runaway problem of the battery and improving the reliability of the battery.

[0046] In some embodiments, along the distribution direction of the first wall and the electrode assembly, the first fire extinguishing part is arranged on the side of the pressure relief part away from the electrode assembly.

[0047] By arranging the first fire extinguishing part on the side of the pressure relief part away from the electrode assembly, the first fire extinguishing part is arranged on the outer side of the pressure relief part, which can improve the problem that the sixth fire extinguishing member blocks the high-temperature and high-pressure gas and flame from passing through the pressure relief part inside the pressure relief part, helps to improve the pressure relief of the battery cell, and can improve the thermal runaway reaction of the battery cell.

[0048] In some embodiments, a third breakable mark is provided between the first fire extinguishing part and the second fire extinguishing part.

[0049] With such an arrangement, it is beneficial for the high-temperature and high-pressure gas and flame inside the battery cell to break through the first fire extinguishing part without affecting the exhaust effect.

[0050] In some embodiments, in the direction perpendicular to the distribution direction of the first wall and the electrode assembly, the size of the second fire extinguishing part is larger than that of the pressure relief part, and the ratio of the size of the pressure relief part to the size of the first fire extinguishing part is ≥0.8 and ≤1.2.

[0051] In this way, on the one hand, the first fire extinguishing part can effectively cool and extinguish the high-temperature and high-pressure gas, flame, etc. that break through the pressure relief part, and on the other hand, the first fire extinguishing part will not overly block and affect the release of the high-temperature and high-pressure gas, flame, etc. Thus, the thermal runaway reaction of the battery cell can be effectively improved.

[0052] In some embodiments, the first fire extinguishing part is provided with a second through hole opposite to the pressure relief part.

[0053] With such an arrangement, when the high-temperature and high-pressure gas and flame inside the battery cell break through the pressure relief part, they can be exhausted through the second through hole, so that the battery cell has a better exhaust effect, which helps to improve the thermal runaway reaction of the battery cell.

[0054] In some embodiments, at least one fire extinguishing structure arranged at the pressure relief part is a seventh fire extinguishing member. Along the distribution direction of the first wall and the electrode assembly, the seventh fire extinguishing member is arranged on the side of the pressure relief part facing the electrode assembly and is arranged opposite to the pressure relief part.

[0055] By arranging the seventh fire extinguishing member, the seventh fire extinguishing member can cool and extinguish the high-temperature and high-pressure gas and flame during the process of the high-temperature and high-pressure gas and flame inside the battery cell being released to the pressure relief part, thereby improving the thermal runaway and thermal spread of the battery cell.

[0056] In some embodiments, the seventh fire extinguishing member is connected to the pressure relief part and is used to move with the pressure relief part.

[0057] By adopting the above technical solution, during the thermal runaway process of the battery cell, when the high-temperature and high-pressure gas and flame generated inside the battery cell break through the pressure relief part, the seventh fire extinguishing member will move along with the pressure relief part, which is conducive to the release of the high-temperature and high-pressure gas and flame. Moreover, as the seventh fire extinguishing member moves along with the pressure relief part, it can continuously perform the operations of cooling and extinguishing the fire, thereby efficiently improving the thermal runaway reaction and thermal propagation problems of the battery cell, improving the battery thermal runaway problem, and enhancing the reliability of the battery.

[0058] In some embodiments, in the distribution direction of the first wall and the electrode assembly, the projection of the seventh fire extinguishing member is located within the projection of the pressure relief part.

[0059] By adopting the above technical solution, the seventh fire extinguishing member will not affect the movement of the pressure relief part relative to the first wall as much as possible, so that the high-temperature and high-pressure gas, flame, etc. can smoothly break through the pressure relief part without being affected by the seventh fire extinguishing member, and the seventh fire extinguishing member can continuously perform the functions of cooling and extinguishing the fire, which helps to improve the thermal runaway reaction and thermal propagation problems of the battery cell.

[0060] In some embodiments, the seventh fire extinguishing member is provided with a third through hole opposite to the pressure relief part.

[0061] With such a setting, the seventh fire extinguishing member has a better exhaust effect and can effectively improve the thermal runaway reaction of the battery cell.

[0062] In some embodiments, the housing assembly further includes a second wall connected to the first wall, and at least one fire extinguishing structure provided at the pressure relief part abuts against the second wall, and the second wall is the wall with the largest area among all the walls of the housing assembly.

[0063] By providing at least one fire extinguishing structure at the pressure relief part to abut against the wall with the largest area among all the walls of the housing assembly, the fire extinguishing structure can be better close to the pressure relief part, so as to effectively cool and extinguish the high-temperature and high-pressure gas and flame at the pressure relief part.

[0064] In some embodiments, the fire extinguishing structure includes a core for extinguishing the fire and a shell for encapsulating the core.

[0065] With such a setting, when the fire extinguishing structure is in a high-temperature environment, the shell of the fire extinguishing structure ruptures, and the core in the shell can reduce the temperature of the high-temperature and high-pressure gas and extinguish the flame to achieve the effect of cooling and extinguishing the fire.

[0066] In some embodiments, the core is a perfluoromethyl hexanone core; and / or, the shell is a polymer shell.

[0067] With such a setting, the fire extinguishing structure can effectively perform the operations of cooling and extinguishing the fire.

[0068] In a second aspect, an embodiment of the present application provides a battery, including a battery cell.

[0069] The battery provided by the embodiment of the present application can improve the problem of thermal runaway of the entire battery and enhance the reliability of the battery by adopting the battery cells involved above.

[0070] In a third aspect, the embodiment of the present application provides an electrical device including a battery.

[0071] The electrical device provided by the embodiment of the present application can improve the reliability of the battery and thus enhance the reliability of the electrical device by adopting the battery involved above.

[0072] The above description is only an overview of the technical solution of the present application. In order to understand the technical means of the present application more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of the present application more obvious and understandable, the following specifically illustrates the specific embodiments of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0074] Figure 1 Schematic diagram of a vehicle provided for some embodiments of the present application;

[0075] Figure 2 Exploded view of a battery provided for some embodiments of the present application;

[0076] Figure 3 Stereoscopic structure diagram of a battery cell provided for some embodiments of the present application;

[0077] Figure 4 For Figure 3 Exploded view;

[0078] Figure 5 For Figure 3 Cross-sectional view along A-A;

[0079] Figure 6 For Figure 5 Enlarged view at B in;

[0080] Figure 7 For Figure 3 Stereoscopic structure diagram of the fire extinguishing structure of the battery cell provided;

[0081] Figure 8 Stereoscopic structure diagram of multiple battery cells provided for some embodiments of the present application;

[0082] Figure 9 is Figure 8 A cross-sectional view along C-C;

[0083] Figure 10 is Figure 9 An enlarged view at D in

[0084] Figure 11 Partial structural diagram of a battery cell provided by some embodiments of the present application;

[0085] Figure 12 is Figure 11 The provided battery cell along Figure 11 A cross-sectional view along E-E in

[0086] Figure 13 is Figure 12 An enlarged view at F in

[0087] Figure 14 is Figure 11 A three-dimensional structural diagram of the housing and fire extinguishing structure of the provided battery cell;

[0088] Figure 15 Partial exploded view of a battery cell provided by some embodiments of the present application;

[0089] Figure 16 is Figure 15 The provided battery cell along Figure 15 A cross-sectional view along G-G of

[0090] Figure 17 is Figure 16 An enlarged view at H in

[0091] Figure 18 Partial structural diagram of a battery cell provided by some embodiments of the present application;

[0092] Figure 19 is Figure 18 An exploded view of

[0093] Figure 20 is Figure 18 A cross-sectional view along I-I;

[0094] Figure 21 is Figure 20 An enlarged view at J in

[0095] Figure 22 is Figure 18 Structural diagram of the fire extinguishing structure of the provided battery cell;

[0096] Figure 23 Cross-sectional view of a battery cell provided by some embodiments of the present application;

[0097] Figure 24 is Figure 23 an enlarged view of the position K in

[0098] Figure 25 a partial structural view of a battery cell according to some embodiments of the present application;

[0099] Figure 26 is Figure 25 a sectional view along L-L;

[0100] Figure 27 is Figure 26 an enlarged view of the position M in

[0101] Figure 28 is Figure 25 a structural view of the fire extinguishing structure of the provided battery cell;

[0102] Figure 29 a partial structural view of a battery cell according to some embodiments of the present application;

[0103] Figure 30 a structural view of a battery cell according to some embodiments of the present application;

[0104] Figure 31 a partial exploded view of a battery cell according to some embodiments of the present application;

[0105] Figure 32 is Figure 31 the sectional view of the provided battery cell along Figure 31 N-N in

[0106] Figure 33 is Figure 32 an enlarged view of the position O in

[0107] Figure 34 is Figure 31 a structural view of the fire extinguishing structure of the provided battery cell.

[0108] Among them, the reference numerals in the figure:

[0109] 1000 - Vehicle; 100 - Battery; 200 - Controller; 300 - Motor; 10 - Battery cell; 20 - Box; 21 - First part; 22 - Second part; 11 - Electrode assembly; 12 - Housing assembly; 121 - Housing; 1211 - Second wall; 122 - End cover; 1221 - First wall; 123 - Weak structure; 123a - Weld seam; 123b - Pressure relief mechanism; 1231b - Pressure relief part; 1232b - Connection part; 1233b - Second breakable mark; 13 - Fire extinguishing structure; 1301 - First through hole; 1302 - Second through hole; 13a - First fire extinguishing member; 13b - Second fire extinguishing member; 13c - Third fire extinguishing member; 13d - Fourth fire extinguishing member; 13e - Fifth fire extinguishing member; 13f - Sixth fire extinguishing member; 131f - First fire extinguishing part; 132f - Second fire extinguishing part; 133f - Third breakable mark; 13g - Seventh fire extinguishing member; 14 - Insulation structure; 1401 - Groove; 141 - Lower plastic; 1411 - First boss; 1412 - Second boss; 142 - Bottom plate; 143 - Insulation film; 30 - Heat insulation member; H1 - First distance; H3 - Third distance; W1 - First dimension; W2 - Second dimension; W3 - Third dimension; W4 - Fourth dimension; W5 - Fifth dimension; W6 - Sixth dimension; W7 - Seventh dimension; W8 - Eighth dimension; W9 - Ninth dimension; W10 - Tenth dimension; W11 - Eleventh dimension; W12 - Twelfth dimension; W13 - Thirteenth dimension; W14 - Fourteenth dimension; W15 - Fifteenth dimension; W16 - Sixteenth dimension; Z - First direction; X - Second direction; Y - Third direction. Detailed implementation manners

[0110] The embodiments of the present application will be described in detail below. Examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present application, and should not be construed as a limitation of the present application.

[0111] In the description of the present application, it should be understood that the orientation or positional relationships indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present application.

[0112] In addition, the terms "first" and "second" are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0113] In the description of the present application, the meaning of "a plurality of" is more than two. Unless otherwise specifically defined, "more than two" includes two. Correspondingly, the meaning of "multiple groups" is more than two groups, including two groups.

[0114] In the description of the present application, unless otherwise clearly specified and defined, terms such as "installed", "connected", "joined", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0115] In the description of the present application, the term "and / or" is merely a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: the existence of A, the simultaneous existence of A and B, and the existence of B. In addition, in the present application, the character " / " generally represents an "or" relationship between the front and back associated objects.

[0116] Although the present application has been described with reference to the preferred embodiments, various improvements can be made to it and components therein can be replaced with equivalents without departing from the scope of the present application. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

[0117] In the related art, during the use of a battery cell, it is inevitable to rapidly generate high temperature, thereby generating high-temperature and high-pressure gas and flame, causing the battery cell to undergo thermal runaway. The high-temperature and high-pressure gas and flame are prone to thermal spread to adjacent battery cells, resulting in a chain reaction of thermal runaway in adjacent battery cells, and further leading to thermal runaway of the entire battery, thus making the reliability of the battery relatively low.

[0118] The battery cell may include an electrode assembly and a housing assembly, and the electrode assembly is disposed within the housing assembly. The housing assembly generally has relatively weak parts. During the thermal runaway of the battery cell, the high-temperature and high-pressure gas and flame generated by the battery cell are prone to breaking through the relatively weak parts of the housing assembly and spraying out from the relatively weak parts of the housing assembly.

[0119] Specifically, the housing assembly is formed with a weld seam and a pressure relief mechanism, which are relatively weak parts in the battery cell. In some cases, during the thermal runaway process of the battery cell, the high-temperature and high-pressure gas and flame generated generally perform directional pressure relief through the pressure relief mechanism. If the pressure relief mechanism fails to exhaust in time, the high-temperature and high-pressure gas and flame will also eject through the weld seam. In this way, high-temperature and high-pressure gas and flame will be ejected during the thermal runaway process of the battery cell, thereby causing thermal spread to adjacent battery cells, resulting in a chain reaction of thermal runaway in adjacent battery cells, and further leading to thermal runaway of the entire battery.

[0120] Based on the above considerations, the embodiments of the present application provide a battery cell, a battery, and an electrical device. By setting the battery cell to include a fire extinguishing structure, and arranging the fire extinguishing structure at at least one of the weld seam and the pressure relief mechanism of the housing assembly, the fire extinguishing structure can perform cooling and fire extinguishing work at at least one of the weld seam and the pressure relief mechanism. In this way, the thermal runaway reaction and thermal spread problems of the battery cell can be improved, thereby improving the problem of the chain reaction of thermal runaway in adjacent battery cells, improving the problem of thermal runaway of the entire battery, and enhancing the reliability of the battery.

[0121] In some embodiments, the battery cell involved in the embodiments of the present application can be used in an electrical device that uses the battery cell or the battery as a power source.

[0122] The electrical device involved in the embodiments of the present application can be, but is not limited to, mobile phones, tablets, laptop computers, electric toys, electric tools, battery cars, vehicles, ships, spacecraft, etc. Among them, electric toys can include fixed or mobile electric toys, such as game consoles, electric vehicle toys, electric ship toys, and electric aircraft toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spaceships, etc. Divided by power source, the vehicle can be a fuel vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, etc. Divided by drive mode, the vehicle can be a front-wheel drive vehicle, a rear-wheel drive vehicle, or a four-wheel drive vehicle.

[0123] In other embodiments, the battery cell involved in the embodiments of the present application can also be used in an energy storage system that uses the battery cell or the battery as an energy storage element. Among them, the energy storage system can include an energy storage container, an energy storage electrical cabinet, etc.

[0124] For ease of description, the embodiments of the present application take the electrical device as a vehicle as an example for illustration.

[0125] In some embodiments, please refer to Figure 1 , Figure 1Schematic diagram of vehicle 1000 provided for some embodiments of the present application. The interior of vehicle 1000 is provided with the above-mentioned battery 100, and the battery 100 can be arranged at the bottom, head or tail of vehicle 1000. The battery 100 can be used for power supply of vehicle 1000. For example, the battery 100 can be used as the operating power source of vehicle 1000. Vehicle 1000 can also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to supply power to the motor 300, for example, for the working power requirements during the start, navigation and driving of vehicle 1000.

[0126] In some embodiments, the battery 100 can not only be used as the operating power source of vehicle 1000, but also as the driving power source of vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for vehicle 1000.

[0127] The battery 100 involved in the embodiments of the present application can be a single physical module including one or more battery cells 10 to provide higher voltage and capacity.

[0128] In some embodiments, the battery 100 can include one battery cell 10.

[0129] In some embodiments, please refer to Figure 2 , Figure 2 Exploded schematic diagram of battery 100 provided for some embodiments of the present application. The battery 100 can include a plurality of battery cells 10. The plurality of battery cells 10 are connected in series, parallel or in a hybrid connection through a busbar component. The hybrid connection means that there are both series and parallel connections among the plurality of battery cells 10.

[0130] In some embodiments, the battery 100 can be a battery module. When there are multiple battery cells 10, the multiple battery cells 10 are arranged and fixed to form a battery module.

[0131] In some embodiments, the battery 100 can be a battery pack. Please refer to Figure 2 , the battery 100 can include a box body 20 and battery cells 10. The box body 20 is a structure with a space inside, and the internal space of the box body 20 is used to accommodate the battery cells 10.

[0132] The box body 20 can adopt various structures. In some embodiments, the box body 20 can include a first part 21 and a second part 22. The first part 21 and the second part 22 cover each other and jointly define the internal space of the box body 20. Among them, the first part 21 can be a hollow structure with an opening at one end, and the second part 22 is a plate-like structure. The second part 22 covers the opening side of the first part 21 so that the first part 21 and the second part 22 jointly define the internal space of the box body 20. Or, please refer to Figure 2, both the first part 21 and the second part 22 can be hollow structures with an opening at one end. The opening side of the first part 21 covers the opening side of the second part 22, so that the first part 21 and the second part 22 jointly define the internal space of the box body 20. Among them, the box body 20 composed of the first part 21 and the second part 22 can be in various shapes, such as a cylinder, a cuboid, etc.

[0133] In some embodiments, please refer to Figure 2 , when the number of battery cells 10 is multiple, the multiple battery cells 10 can be formed into a whole through series connection, parallel connection or hybrid connection, and then the whole formed by the multiple battery cells 10 is directly accommodated in the internal space of the box body 20. In other embodiments, when the number of battery cells 10 is multiple, the multiple battery cells 10 can also be first connected in series, parallel or in a hybrid manner, arranged and fixed to form a battery module, and the battery module is accommodated in the internal space of the box body 20. In still other embodiments, when the number of battery cells 10 is multiple, the multiple battery cells 10 can also be first connected in series, parallel or in a hybrid manner, arranged and fixed to form multiple battery modules, and the multiple battery modules are then connected in series, parallel or in a hybrid manner to form a whole and are accommodated in the internal space of the box body 20.

[0134] As an example, multiple battery cells 10 can be fixed to form a battery module through cable ties or the like.

[0135] As an example, multiple battery cells 10 can be fixed to form a battery module through end plates, side plates or the like.

[0136] In some embodiments, the box body 20 of the battery 100 can be a part of the chassis structure of the vehicle 1000. For example, a part of the box body 20 can become at least a part of the chassis of the vehicle 1000, or a part of the box body 20 can become at least a part of the cross beam and longitudinal beam of the vehicle 1000.

[0137] The battery cell 10 involved in the embodiments of the present application refers to the smallest unit for storing and outputting electric energy. Among them, the battery cell 10 can be a secondary battery or a primary battery. The battery cell 10 can be, but is not limited to, a metal battery, a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery. The battery cell 10 can be in the shape of a cylinder, a flat body, a cuboid or other shapes, etc.

[0138] In some embodiments, please refer to Figures 3 to 5 , Figure 3 is a three-dimensional structure diagram of the battery cell 10 provided in some embodiments of the present application, Figure 4 is Figure 3 exploded view of Figure 5 is Figure 3 A cross-sectional view taken along A-A. Among them, the battery cell 10 can include an electrode assembly 11 and a housing assembly 12.

[0139] The electrode assembly 11 is a component in the battery cell 10 where electrochemical reactions occur. Among them, the electrode assembly 11 is mainly formed by winding or laminating a positive electrode sheet and a negative electrode sheet, and a separator is provided between the positive electrode sheet and the negative electrode sheet. The parts of the positive electrode sheet and the negative electrode sheet with active materials constitute the main body of the electrode assembly 11, and the parts of the positive electrode sheet and the negative electrode sheet without active materials respectively constitute the electrode tabs. The electrode tab of the positive electrode sheet is the positive electrode tab, and the electrode tab of the negative electrode sheet is the negative electrode tab. The positive electrode tab and the negative electrode tab can be located at one end of the main body together or at opposite ends of the main body respectively.

[0140] In the battery cell 10, the number of electrode assemblies 11 can be one or multiple.

[0141] In some cases, the electrode assembly 11 can also be referred to as a bare battery cell, a wound body, a laminated body, etc.

[0142] In some embodiments, the battery cell 10 may further include an electrolyte, and the electrolyte functions to conduct ions between the positive electrode sheet and the negative electrode sheet. Among them, the electrolyte involved in the embodiments of the present application can be liquid, gel-like or solid.

[0143] The housing assembly 12 is a component structure for defining the internal environment of the battery cell 10, and the housing assembly 12 is used to accommodate the electrode assembly 11 and the electrolyte.

[0144] In some embodiments, please continue to refer to Figures 3 to 5 , the housing assembly 12 may include a housing 121 and an end cap 122. The housing 121 and the end cap 122 are components for jointly defining the internal environment of the battery cell 10, and the internal environment defined by the housing 121 and the end cap 122 is used to accommodate the electrode assembly 11 and the electrolyte. Among them, the housing 121 and the end cap 122 can be independent components. Specifically, the housing 121 has an opening, and the end cap 122 is covered on the opening of the housing 121 to jointly define the internal environment of the battery cell 10 with the housing 121 and isolate the internal environment of the battery cell 10 from the external environment. Or, the housing 121 and the end cap 122 can also be an integrated structure. Specifically, a common connection surface can be formed between the end cap 122 and the housing 121 before the electrode assembly 11 is inserted into the housing. When the electrode assembly 11 needs to be encapsulated after being inserted into the housing, the end cap 122 is then covered on the housing 121.

[0145] Among them, the number of end caps 122 can be one, as Figures 3 to 5 shown. Or, the number of end caps 122 can also be two, and the two end caps 122 are respectively provided at opposite ends of the housing 121.

[0146] The shell 121 may be cylindrical, square, or other shapes, which may be determined according to the specific shape and size of the electrode assembly 11. In addition, the shell 121 and the end cap 122 may be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, or the like.

[0147] Please also read Figures 3 to 6 , Figures 18 to 22 , and combined with other drawings. Among them, Figure 6 for Figure 5 Enlarged view of point B in the middle. Figure 18 A partial structural diagram of a battery 10 provided in some embodiments of the present application, Figure 19 for Figure 18 An exploded diagram of Figure 20 for Figure 18 Sectional view along II, Figure 21 for Figure 20 The enlarged image of J in the middle. Figure 22 for Figure 18 A structural diagram of a fire extinguishing structure 13 of a battery cell 10 is provided. The battery cell 10 provided in the embodiment of the present application includes a housing assembly 12, an electrode assembly 11 and a fire extinguishing structure 13. The housing assembly 12 is provided with a weak structure 123. The electrode assembly 11 is provided in the housing assembly 12. The fire extinguishing structure 13 is provided at the weak structure 123.

[0148] The weak structure 123 refers to the relatively weak part of the shell assembly 12. During the thermal runaway of the battery cell 10, due to the relatively weak design of the weak structure 123, the high-temperature and high-pressure gas and flame generated by the battery cell 10 can easily break through the weak structure 123 and spray out from the weak structure 123. Among them, the weak structure 123 can include at least one of the weld 123a and the pressure relief mechanism 123b mentioned below. Among them, the shell 121 of the shell assembly 12 can be provided with a weak structure 123; the end cover 122 of the shell assembly 12 can also be provided with a weak structure 123; and a weak structure 123 can also be provided between the shell 121 and the end cover 122 of the shell assembly 12.

[0149] The fire extinguishing structure 13 refers to a structure made of fire extinguishing material and having a fire extinguishing function. Specifically, the fire extinguishing structure 13 can suppress the generation and spread of flames, and can take away the heat in the high-temperature and high-pressure gas and flames during operation to achieve the cooling and fire extinguishing function. That is, the fire extinguishing structure 13 is mainly used for cooling and fire extinguishing.

[0150] The fire extinguishing structure 13 is provided at the weak structure 123, which means that the fire extinguishing structure 13 is provided at a position where the weak structure 123 can be cooled and extinguished. Among them, the fire extinguishing structure 13 provided at the weak structure 123 can be attached to the weak structure 123; it can also be provided near the weak structure 123 and arranged at intervals with the weak structure 123. That is, the fire extinguishing structure 13 can be used to cool and extinguish the weak structure 123, which can be understood as the fire extinguishing structure 13 is provided at the weak structure 123. Based on this, the fire extinguishing structure 13 is provided at the weak structure 123, so that the fire extinguishing structure 13 can cool and extinguish the weak structure 123. In this way, the temperature of the high-temperature and high-pressure gas ejected from the weak structure 123 can be reduced, and the flame ejected from the weak structure 123 can be extinguished.

[0151] Based on the above structure, in some possible designs, please refer to Figures 3 to 6 together with other drawings. The housing assembly 12 is formed with a weld 123a, and at least one fire extinguishing structure 13 is provided at the weld 123a. It can be understood that the weak structure 123 includes the weld 123a, that is, at least part of the weak structure 123 is the weld 123a.

[0152] The weld 123a is the trace formed by welding the housing assembly 12.

[0153] At least one fire extinguishing structure 13 is provided at the weld 123a, which means that at least one fire extinguishing structure 13 is provided at a position where the weld 123a can be cooled and extinguished. Among them, at least one fire extinguishing structure 13 provided at the weld 123a can be attached to the weld 123a; it can also be provided near the weld 123a and arranged at intervals with the weld 123a. That is, the fire extinguishing structure 13 can be used to cool and extinguish the weld 123a, which can be understood as the fire extinguishing structure 13 is provided at the weld 123a.

[0154] At least one fire extinguishing structure 13 provided near the weld 123a and arranged at intervals with the weld 123a can be attached to other positions of the housing assembly 12 except the weld 123a, for example, it can be attached to at least one of other positions of the housing 131 of the housing assembly 12 except the weld 123a and other positions of the end cover 122 except the weld 123a.

[0155] At least one fire extinguishing structure 13 provided near the weld 123a and arranged at intervals with the weld 123a can also be provided on the insulating structure 14, for example, it can be provided on the lower plastic 141, as Figures 11 to 17 shown.

[0156] Based on this, at least one fire extinguishing structure 13 is provided at the weld 123a, so that the fire extinguishing structure 13 can cool down and extinguish the fire at the weld 123a. In this way, the temperature of the high-temperature and high-pressure gas ejected from the weld 123a can be reduced, and the flame ejected from the weld 123a can be extinguished.

[0157] Based on the above structure, in some possible designs, please refer to Figures 18 to 22 , and in combination with other drawings. The housing assembly 12 is formed with a pressure relief mechanism 123b, and at least one fire extinguishing structure 13 is provided at the pressure relief mechanism 123b. It can be understood that the weak structure 123 includes the pressure relief mechanism 123b, that is, at least part of the weak structure 123 is the pressure relief mechanism 123b.

[0158] The pressure relief mechanism 123b is a mechanism that can release the internal pressure of the battery cell 10 when the internal pressure or temperature of the battery cell 10 reaches a threshold value. For example, when the battery cell 10 is working normally, the gas pressure inside the battery cell 10 is less than the opening pressure value of the pressure relief mechanism 123b, and the pressure relief mechanism 123b is in a closed state, and the gas inside the battery cell 10 is not connected to the gas outside. When the battery cell 10 undergoes thermal runaway under the action of internal and external factors such as overcharging, over-discharging, overheating, and mechanical collision, a large amount of high-temperature and high-pressure gas is generated inside the battery cell 10, making the internal pressure of the battery cell 10 greater than the opening pressure value of the pressure relief mechanism 123b. The pressure relief mechanism 123b changes from the closed state to the open state, and the high-temperature and high-pressure gas inside the battery cell 10 can be discharged to the outside of the battery cell 10 through the pressure relief mechanism 123b.

[0159] The pressure relief mechanism 123b can be a structure with at least part of its structural strength lower than other parts of the housing assembly 12, or the pressure relief mechanism 123b can also be a pressure valve or the like. In this way, when the battery cell 10 undergoes thermal runaway, the high-temperature and high-pressure gas and flame generated by the battery cell 10 can break through the pressure relief mechanism 123b to be released to the outside of the battery cell 10.

[0160] Among them, the housing 121 of the housing assembly 12 can be provided with the pressure relief mechanism 123b. The end cover 122 of the housing assembly 12 can also be provided with the pressure relief mechanism 123b.

[0161] At least one fire extinguishing structure 13 is provided at the pressure relief mechanism 123b, which means that at least one fire extinguishing structure 13 is provided at a position where the pressure relief mechanism 123b can be cooled down and extinguished. Among them, at least one fire extinguishing structure 13 provided at the pressure relief mechanism 123b can be attached to the pressure relief mechanism 123b; it can also be provided near the pressure relief mechanism 123b and arranged at intervals with the pressure relief mechanism 123b. That is, the fire extinguishing structure 13 can be used to cool down and extinguish the pressure relief mechanism 123b, which can be understood as the fire extinguishing structure 13 is provided at the pressure relief mechanism 123b.

[0162] At least one fire extinguishing structure 13, which is disposed near the pressure relief mechanism 123b and spaced apart from the pressure relief mechanism 123b, can be disposed at other positions of the housing assembly 12 except the pressure relief mechanism 123b. For example, it can be disposed on the first wall 1221 of the housing assembly 12, and can also be disposed on the housing 121 of the housing assembly 12.

[0163] At least one fire extinguishing structure 13, which is disposed near the pressure relief mechanism 123b and spaced apart from the pressure relief mechanism 123b, can also be disposed on the connecting portion 1232b of the pressure relief mechanism 123b, can also be disposed on the lower plastic 141 of the insulating structure 14, and can also be disposed on the bottom support plate 142 of the insulating structure 14.

[0164] Among them, at least one fire extinguishing structure 13 disposed at the pressure relief mechanism 123b can be disposed outside the housing assembly 12. The fire extinguishing structure 13 can be connected to or spaced apart from the first fire extinguishing member 13a, and can also be connected to or spaced apart from the second fire extinguishing member 13b.

[0165] Among them, at least one fire extinguishing structure 13 disposed at the pressure relief mechanism 123b can be disposed inside the housing assembly 12. The fire extinguishing structure 13 can be connected to or spaced apart from the third fire extinguishing member 13c, and can also be connected to or spaced apart from the fourth fire extinguishing member 13d.

[0166] Based on this, at least one fire extinguishing structure 13 is disposed at the pressure relief mechanism 123b, so that the fire extinguishing structure 13 can cool down and extinguish the fire at the pressure relief mechanism 123b. In this way, the temperature of the high-temperature and high-pressure gas ejected from the pressure relief mechanism 123b can be reduced, and the flame ejected from the pressure relief mechanism 123b can be extinguished. That is, at least one fire extinguishing structure 13 is disposed at the pressure relief mechanism 123b to cool down and extinguish the high-temperature and high-pressure gas and flame ejected from the pressure relief mechanism 123b, thereby improving the thermal runaway reaction and thermal spread of the battery cell 10 and improving the reliability of the battery 100.

[0167] In the battery cell 10 provided by the embodiment of the present application, by setting the battery cell 10 to include a fire extinguishing structure 13, and at least one of the weld 123a and the pressure relief mechanism 123b of the housing assembly 12 is provided with a fire extinguishing structure 13, so that the fire extinguishing structure 13 can cool down and extinguish the fire at at least one of the weld 123a and the pressure relief mechanism 123b. Specifically, it can suppress the generation and propagation of the flame at at least one of the weld 123a and the pressure relief mechanism 123b, and reduce the temperature of the high-temperature and high-pressure gas at at least one of the weld 123a and the pressure relief mechanism 123b. In this way, the thermal runaway reaction and thermal spread problems of the battery cell 10 can be improved, thereby improving the problem of the chain reaction of thermal runaway of adjacent battery cells 10, and improving the problem of thermal runaway of the entire battery 100, and improving the reliability of the battery 100.

[0168] It should be noted here that when the number of battery cells 10 is multiple, the fire extinguishing structures 13 of the multiple battery cells 10 can be connected to each other or distributed at intervals.

[0169] In some embodiments, please refer to Figures 3 to 10 together and in combination with other drawings. Among them, Figure 7 is Figure 3 a three-dimensional structure diagram of the fire extinguishing structure 13 of the provided battery cell 10, Figures 3 to 7 and the fire extinguishing structure 13 in Figure 8 is the first fire extinguishing member 13a. Figure 9 is Figure 8 a cross-sectional view along C-C, Figure 10 is Figure 9 an enlarged view of D in Figures 8 to 10 and the fire extinguishing structure 13 in

[0170] Among them, as Figures 3 to 10 shown, at least one fire extinguishing structure 13 provided at the weld 123a can be attached to the weld 123a on the housing assembly 12. At least one fire extinguishing structure 13 provided at the weld 123a can also be attached to other positions of the housing assembly 12 other than the weld 123a.

[0171] Among them, as Figures 3 to 6 shown, at least one fire extinguishing structure 13 provided at the weld 123a can be attached to the end cap 122 of the housing assembly 12. As Figures 8 to 10 shown, at least one fire extinguishing structure 13 provided at the weld 123a can also be attached to the housing 121 of the housing assembly 12.

[0172] Among them, as Figures 3 to 10 shown, at least one fire extinguishing structure 13 provided at the weld 123a can be attached to the outer wall of the housing assembly 12. At least one fire extinguishing structure 13 provided at the weld 123a can also be attached to the inner wall of the housing assembly 12.

[0173] In some embodiments, please refer to Figures 18 to 25 together and in combination with other drawings. Among them, Figure 23 is a cross-sectional view of the battery cell 10 provided in some embodiments of the present application, Figure 24 is Figure 23 an enlarged view of K in Figures 18 to 24 and the fire extinguishing structure 13 in Figure 25Partial structural diagram of the battery cell 10 provided for some embodiments of the present application. At least one fire extinguishing structure 13 provided at the pressure relief mechanism 123b abuts against the housing assembly 12.

[0174] Among them, as Figures 18 to 25 shown, at least one fire extinguishing structure 13 provided at the pressure relief mechanism 123b may abut against the pressure relief mechanism 123b of the housing assembly 12. At least one fire extinguishing structure 13 provided at the pressure relief mechanism 123b may also abut against other positions of the housing assembly 12 other than the pressure relief mechanism 123b.

[0175] Among them, at least one fire extinguishing structure 13 provided at the pressure relief mechanism 123b may abut against the end cover 122 of the housing assembly 12, or may abut against the housing 121 of the housing assembly 12.

[0176] Among them, as Figures 18 to 24 shown, at least one fire extinguishing structure 13 provided at the pressure relief mechanism 123b may abut against the inner wall of the housing assembly 12. As Figure 25 shown, at least one fire extinguishing structure 13 provided at the pressure relief mechanism 123b may also abut against the outer wall of the housing assembly 12.

[0177] In some embodiments, please refer to Figures 11 to 24 together and in combination with other drawings. Among them, Figure 11 is a partial structural diagram of the battery cell 10 provided for some embodiments of the present application, Figure 12 is Figure 11 a cross-sectional view of the battery cell 10 provided along Figure 11 E-E in Figure 13 is Figure 12 an enlarged view of the F position in Figure 14 is Figure 11 a three-dimensional structural diagram of the housing 121 and the fire extinguishing structure 13 of the battery cell 10 provided, Figures 11 to 14 The fire extinguishing structure 13 in Figure 15 is the third fire extinguishing member 13c. Figure 16 is a partial exploded view of the battery cell 10 provided for some embodiments of the present application, Figure 15 is Figure 15 a cross-sectional view of the battery cell 10 provided along Figure 17 G-G of Figure 16 is Figures 15 to 17 an enlarged view of the H position in

[0178] In some possible designs, as Figures 11 to 17 shown, at least one fire extinguishing structure 13 provided at the weld 123a is provided on the insulating structure 14.

[0179] In some possible designs, such as Figure 18 and Figure 24 shown, at least one fire extinguishing structure 13 provided at the pressure relief mechanism 123b is provided on the insulating structure 14.

[0180] The insulating structure 14 is provided with components having insulating properties. The insulating structure 14 is provided between the housing assembly 12 and the electrode assembly 11 for achieving insulation between the housing assembly 12 and the electrode assembly 11.

[0181] Among them, the insulating structure 14 being provided between the housing assembly 12 and the electrode assembly 11 means that the insulating structure 14 is provided between the main part of the electrode assembly 11 and the inner wall of the housing assembly 12. Among them, the main part of the electrode assembly 11 may be the main body part of the electrode assembly 11.

[0182] In some possible designs, such as Figures 11 to 22 shown, the insulating structure 14 may include a lower plastic 141. The lower plastic 141 is provided between the main body part of the electrode assembly 11 and the inner wall of the housing assembly 12. Specifically, the lower plastic 141 is provided between the end of the main body part having a tab and the inner wall of the housing assembly 12 to achieve insulation between the electrode assembly 11 and the housing assembly 12.

[0183] Among them, at least one fire extinguishing structure 13 provided at the weld 123a may be provided on the lower plastic 141, such as Figures 11 to 17 shown. At least one fire extinguishing structure 13 provided at the pressure relief mechanism 123b may also be provided on the lower plastic 141, such as Figures 18 to 22 shown.

[0184] In some possible designs, such as Figure 23 and Figure 24 shown, the insulating structure 14 includes a bottom support plate 142. The bottom support plate 142 is provided between the electrode assembly 11 and the inner wall of the housing assembly 12. The bottom support plate 142 is used to support the electrode assembly 11 and is used to achieve insulation between the electrode assembly 11 and the housing assembly 12.

[0185] Among them, at least one fire extinguishing structure 13 provided at the weld 123a may be provided on the bottom support plate 142. As Figure 23 and Figure 24 shown, at least one fire extinguishing structure 13 provided at the pressure relief mechanism 123b may also be provided on the bottom support plate 142.

[0186] As an example, the tab of the electrode assembly 11 is provided at one end of the main body part. The lower plastic 141 is provided between the end of the main body part having the tab and the inner wall of the housing assembly 12. The bottom support plate 142 is provided between the end of the main body part away from the tab and the housing assembly 12.

[0187] In some possible designs, the insulating structure 14 includes an insulating film 143, and the insulating film 143 wraps the electrode assembly 11. At least one fire extinguishing structure 13 provided at the weld 123a can be provided on the insulating film 143, and at least one fire extinguishing structure 13 provided at the pressure relief mechanism 123b can also be provided on the insulating film 143.

[0188] By adopting the above technical solution, at least one fire extinguishing structure 13 can be abutted against the housing assembly 12 or can be provided on the insulating structure 14 within the housing assembly 12 to cool and extinguish the fire at least at one of the weld 123a and the pressure relief mechanism 123b of the housing assembly 12, so that the arrangement of the fire extinguishing structure 13 can be very flexible.

[0189] Based on the above structure, at least one fire extinguishing structure 13 can be provided outside the housing assembly 12, as Figures 3 to 10 shown. With this arrangement, during the thermal runaway process of the battery cell 10, when the high-temperature and high-pressure gas and flame generated spray out from at least one of the weld 123a and the pressure relief mechanism 123b of the weak structure 123, the fire extinguishing structure 13 can cool and extinguish the fire at least at one of the weld 123a and the pressure relief mechanism 123b of the weak structure 123 to improve the thermal runaway reaction of the battery cell 10. Moreover, the fire extinguishing structure 13 can also block the high-temperature and high-pressure gas and flame generated by the battery cell 10 to a certain extent. In this way, the thermal spread of thermal runaway can be effectively slowed down, so that the problem of the chain reaction of adjacent battery cells 10 being affected and having thermal runaway can be improved. In addition, when the high-temperature and high-pressure gas and flame generated during the thermal runaway of the battery cell 10 spread to adjacent battery cells 10, the fire extinguishing structure 13 of the adjacent battery cells 10 can further cool and extinguish the fire of the high-temperature and high-pressure gas and flame and further block it, so that the problem of the adjacent battery cells 10 being affected by the chain reaction of thermal runaway can be further improved, and the reliability of the battery 100 can be improved.

[0190] Based on the above structure, at least one fire extinguishing structure 13 can be provided inside the housing assembly 12, as Figures 11 to 17 、 Figure 23 and Figure 24As shown in the figure. With such a setting, during the thermal runaway process of the battery cell 10, when the high-temperature and high-pressure gas and flame generated spray out from at least one of the weld 123a of the weak structure 123 and the pressure relief mechanism 123b, the fire extinguishing structure 13 cools down and extinguishes the fire at at least one of the weld 123a of the weak structure 123 and the pressure relief mechanism 123b, which can improve the thermal runaway reaction of the battery cell 10. Moreover, the fire extinguishing structure 13 can block the high-temperature and high-pressure gas and flame generated by the battery cell 10 to a certain extent. In this way, the thermal spread of the battery cell 10 can be slowed down, thereby improving the problem of the chain reaction of adjacent battery cells 10 being affected and suffering from thermal runaway, and enhancing the reliability of the battery 100.

[0191] In some embodiments, please refer to Figures 3 to 17 , and in combination with other drawings. The housing assembly 12 includes a housing 121 and an end cap 122. The end cap 122 is disposed on the housing 121 and encloses a space with the housing 121 for accommodating the electrode assembly 11.

[0192] In some embodiments, please refer to Figures 3 to 17 , and in combination with other drawings. A first weld is formed between the housing 121 and the end cap 122. The weld 123a includes the first weld, and at least one fire extinguishing structure 13 disposed at the weld 123a is disposed at the first weld.

[0193] The first weld refers to the trace formed by welding the housing 121 and the end cap 122. Among them, Figures 3 to 17 the weld 123a in

[0194] is the first weld. The weld 123a including the first weld means that at least part of the weld 123a is the first weld.

[0195] At least one fire extinguishing structure 13 is disposed at the first weld, so that at least one fire extinguishing structure 13 can perform the operation of cooling down and extinguishing the fire on the first weld.

[0196] In some embodiments, the housing 121 forms a second weld. The weld 123a includes the second weld, and at least one fire extinguishing structure 13 disposed at the weld 123a is disposed at the second weld.

[0197] The second weld refers to the trace formed by the housing 121 welding itself.

[0198] The weld 123a including the second weld means that at least part of the weld 123a is the second weld.

[0199] At least one fire extinguishing structure 13 is disposed at the second weld, so that at least one fire extinguishing structure 13 can perform the operation of cooling down and extinguishing the fire on the second weld.

[0200] Based on the above structure, the type and position of the weld seam 123a can be various, and temperature reduction and fire extinguishing can be achieved through the fire extinguishing structure 13 in all cases.

[0201] In some embodiments, please refer to Figures 3 to 17 together and in combination with other drawings. The end cover 122 is provided at the end of the housing 121 along the first direction Z.

[0202] Among them, the end cover 122 and the housing 121 can be arranged in sequence along the first direction Z. Or, as Figures 3 to 17 shown, the end cover 122 can be provided at the opening at the end of the housing 121 along the first direction Z, so that the housing 121 is substantially disposed around the outer periphery of the end cover 122 around the first direction Z, that is, the end cover 122 and the housing 121 are substantially distributed in a direction perpendicular to the first direction Z.

[0203] Specifically, the two opposite ends of the end cover 122 along the second direction X and the two opposite ends of the end cover 122 along the third direction Y are respectively welded to the housing 121 to form a first weld seam. That is, among the ends of the housing assembly 12 along the first direction Z, the two opposite ends of the end along the second direction X and the two opposite ends of the end along the third direction Y are respectively formed with a first weld seam.

[0204] Among them, the first direction Z is perpendicular to the second direction X, the second direction X is perpendicular to the third direction Y, and the first direction Z is perpendicular to the third direction Y.

[0205] In some cases, the first direction Z can be the height direction of the battery cell 10. The second direction X can be the width direction of the battery cell 10, that is, the thickness direction of the battery cell 10. The third direction Y can be the length direction of the battery cell 10.

[0206] In some cases, the height of the battery cell 10 is greater than the length of the battery cell 10, and the length of the battery cell 10 is greater than the width of the battery cell 10.

[0207] In some embodiments, please refer to Figures 3 to 7 together and in combination with other drawings. At least one fire extinguishing structure 13 provided at the first weld seam is a first fire extinguishing member 13a, and the first fire extinguishing member 13a abuts against the outer wall of the housing assembly 12 along the first direction Z. On the projection plane perpendicular to the first direction Z, along the width direction of the first weld seam, the distance between the outer edge of the housing assembly 12 and the first fire extinguishing member 13a is ≤ 6 mm.

[0208] Understandably, the first fire extinguishing member 13a abuts against the outer wall of the housing assembly 12 that is away from the electrode assembly 11 in the first direction Z. Among them, the first fire extinguishing member 13a can abut against the outer wall of the end cover 122 of the housing assembly 12 that is away from the electrode assembly 11 in the first direction Z, or can also abut against the outer wall of the housing 121 of the housing assembly 12 that is away from the electrode assembly 11 in the first direction Z.

[0209] On the projection plane perpendicular to the first direction Z, the distance between the outer edge of the part of the housing assembly 12 with the first weld seam in the width direction of the first weld seam and the first fire extinguishing member 13a is ≤ 6 mm, and specifically, it can be 0, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, etc.

[0210] In some possible designs, such as Figure 5 and Figure 6 As shown, first weld seams are formed between the two opposite ends of the end cover 122 in the second direction X and the housing 121, so that in the end of the housing assembly 12 in the first direction Z, first weld seams are formed at the two opposite ends of this end in the second direction X. Among them, in the end of the housing assembly 12 in the first direction Z, the width direction of the first weld seams at the two opposite ends of this end in the second direction X is the second direction X. The first fire extinguishing member 13a abuts against the outer wall of at least one end of the end of the housing assembly 12 in the first direction Z in the second direction X in the first direction Z. And, in the second direction X, the distance between the outer edge of the part of the housing assembly 12 with the first weld seam and the first fire extinguishing member 13a is the first distance H1, and the first distance H1 ≤ 6 mm. In this way, the first fire extinguishing member 13a abuts against the outer wall of the housing assembly 12 at the first weld seam of at least one end of the end cover 122 in the second direction X in the first direction Z.

[0211] As an example, such as Figure 5 and Figure 6 As shown, on the cross-section perpendicular to the third direction Y, the distance between the left outer edge of the housing assembly 12 in the second direction X and the left edge of the first fire extinguishing member 13a in the second direction X is the first distance H1.

[0212] In some other possible designs, first weld seams are formed between two opposite end portions of the end cap 122 along the third direction Y and the housing 121, such that among the end portions of the housing assembly 12 along the first direction Z, first weld seams are formed between two opposite end portions of this end portion along the third direction Y. Among the end portions of the housing assembly 12 along the first direction Z, the width direction of the first weld seams between two opposite end portions of this end portion along the third direction Y is the third direction Y. The first fire extinguishing member 13a abuts against the outer wall along the first direction Z of at least one end portion of the end portion of the housing assembly 12 along the third direction Y. And, in the third direction Y, the distance between the outer edge of the portion of the housing assembly 12 having the first weld seam and the first fire extinguishing member 13a is a second distance, and the second distance ≤ 6 mm. Thus, the first fire extinguishing member 12a abuts against the first weld seam at at least one end portion of the outer wall of the housing assembly 12 along the first direction Z and along the second direction X of the end cap 122.

[0213] As an example, as Figures 3 to 7 shown, first weld seams are respectively formed between two opposite end portions of the end cap 122 along the second direction X and between two opposite end portions of the end cap 122 along the third direction Y and the housing 121, such that among the end portions of the housing assembly 12 along the first direction Z, first weld seams are respectively formed between two opposite end portions of this end portion along the second direction X and between two opposite end portions of this end portion along the third direction Y, and among the outer walls of the housing assembly 12 along the first direction Z, the first fire extinguishing member 13a abuts against the first weld seams at two opposite end portions of the end cap 122 along the second direction X and at the first weld seams at two opposite end portions of the end cap 122 along the third direction Y, such that the first fire extinguishing member 13a is arranged around the first direction Z.

[0214] Wherein, when the number of the first fire extinguishing members 13a is multiple, the multiple first fire extinguishing members 13a can be connected to each other or arranged at intervals.

[0215] By adopting the above technical solution, the first fire extinguishing member 13a abuts against the outer wall of the housing assembly 12 along the first direction Z and is arranged at the first weld seam, so that the first weld can be cooled and extinguished.

[0216] In some embodiments, at least one fire extinguishing structure 13 arranged at the first weld seam is a second fire extinguishing member 13b, and the second fire extinguishing member 13b abuts against the outer wall of the housing assembly 12 along the direction perpendicular to the first direction Z. Along the first direction Z, the distance between the outer edge of the housing assembly 12 and the second fire extinguishing member 13b ≤ 6 mm.

[0217] In some possible designs, as Figures 8 to 10 shown, the direction perpendicular to the first direction Z may include the second direction X.

[0218] Specifically, the second fire extinguishing member 13b abuts against the outer wall of the housing assembly 12 along the second direction X, and in the first direction Z, the distance between the outer edge of the portion of the housing assembly 12 having the first weld seam and the second fire extinguishing member 13b is the third distance H3. Thus, the second fire extinguishing member 13b abuts against the outer wall of the housing assembly 12 at the first weld seam along the second direction X.

[0219] In some possible designs, such as Figures 8 to 10 shown, the direction perpendicular to the first direction Z may include the third direction Y.

[0220] Specifically, the second fire extinguishing member 13b abuts against the outer wall of the housing assembly 12 along the third direction Y, and in the first direction Z, the distance between the outer edge of the portion of the housing assembly 12 having the first weld seam and the second fire extinguishing member 13b is the third distance H3. The third distance H3 ≤ 6 mm, and specifically may be 0, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, etc. Thus, the second fire extinguishing member 13b abuts against the outer wall of the housing assembly 12 at the first weld seam along the third direction Y.

[0221] Wherein, when the number of the second fire extinguishing members 13b is multiple, the multiple second fire extinguishing members 13b may be connected to each other or arranged at intervals.

[0222] Wherein, the first fire extinguishing member 13a and the second fire extinguishing member 13b may be connected to each other or distributed at intervals.

[0223] By adopting the above technical solution, the second fire extinguishing member 13b abuts against the outer wall of the housing assembly 12 along the direction perpendicular to the first direction Z and is arranged at the first weld seam, so that the first weld seam can be cooled and extinguished.

[0224] As above, at least one fire extinguishing structure 13 can abut against the outer wall of the housing assembly 12 and is arranged at the first weld seam, so that the cooling and extinguishing operation can be carried out at the first weld seam to improve the thermal runaway reaction and thermal propagation of the battery cell 10, thereby improving the thermal runaway of the battery 100 and enhancing the reliability of the battery 100.

[0225] In some embodiments, please refer to Figures 3 to 10 together and in combination with other drawings. At least one fire extinguishing structure 13 arranged at the weld seam 123a abuts against the surface of the weld seam 123a.

[0226] Wherein, at least one fire extinguishing structure 13 can abut against the outer surface of the weld seam 123a. At least one fire extinguishing structure 13 can also abut against the inner surface of the weld seam 123a.

[0227] As an example, such as Figures 3 to 6As shown, the first fire extinguishing member 13a abuts against the outer surface of the first weld away from the electrode assembly 11.

[0228] As an example, as Figures 8 to 10 shown, the second fire extinguishing member 13b abuts against the outer surface of the first weld away from the electrode assembly 11.

[0229] By adopting the above technical solution, the fire extinguishing structure 13 abuts against the surface of the weld 123a, so that the cooling and fire extinguishing effect of the fire extinguishing structure 13 on the weld 123a can be improved, thereby better improving the thermal runaway and thermal propagation problems of the battery cell 10 and enhancing the reliability of the battery 100.

[0230] In some embodiments, please refer to Figures 3 to 6 together and in combination with other drawings. On the projection plane perpendicular to the first direction Z, the first fire extinguishing member 13a covers more than 80% of the first weld in the width direction, specifically it can be 80%, 81%, 82%, 85%, 88%, 90%, 91%, 92%, 95%, 98%, 100%, etc.

[0231] As an example, as Figure 5 and Figure 6 shown, the width direction of the first weld is the second direction X. On the cross-section perpendicular to the third direction Y, the projection line of the first fire extinguishing member 13a on the first weld covers more than 80% of the first weld. That is, on the projection plane perpendicular to the first direction Z, the first fire extinguishing member 13a covers more than 80% of the first weld in the width direction.

[0232] In this way, the first fire extinguishing member 13a can be as close as possible to the first weld, so that the cooling and fire extinguishing effect of the first fire extinguishing member 13a on the first weld can be improved, which helps to improve the thermal runaway and thermal propagation problems of the battery cell 10.

[0233] In some embodiments, please refer to Figures 8 to 10 together and in combination with other drawings. On the cross-section parallel to the first direction Z, the projection line of the second fire extinguishing member 13b on the first weld covers more than 80% of the first weld 123a, specifically it can be 80%, 81%, 82%, 85%, 88%, 90%, 91%, 92%, 95%, 98%, 100%, etc.

[0234] In this way, the second fire extinguishing member 13b can be as close as possible to the first weld, so that the cooling and fire extinguishing effect of the second fire extinguishing member 13b on the first weld can be improved, which helps to improve the thermal runaway and thermal propagation problems of the battery cell 10.

[0235] By adopting the above technical solution, the fire extinguishing structure 13 can be as close as possible to the first weld, so as to improve the cooling and fire extinguishing effect of the fire extinguishing structure 13 on the first weld, which helps to improve the problems of thermal runaway and thermal propagation of the battery cell 10, and improve the reliability of the battery 100.

[0236] In some embodiments, please refer to Figure 5 and Figure 6 , and in combination with other drawings. On the projection plane perpendicular to the first direction Z, along the width direction of the first weld, the outer edge of the housing assembly 12 extends beyond or is flush with the first fire extinguishing member 13a.

[0237] With such a setting, on the basis that the first fire extinguishing member 13a can effectively cool and extinguish the fire at the weld 123a, the size of the battery cell 10 will not be increased additionally, and the large energy density of the battery cell 10 can be effectively maintained.

[0238] In some embodiments, please refer to Figure 5 and Figure 6 , and in combination with other drawings. The first distance H1 ≤ 2 mm, specifically it can be 0, 0.5 mm, 1 mm, 1.5 mm, 2 mm, etc.

[0239] With such a setting, a small assembly tolerance is provided between the first fire extinguishing member 13a and the housing assembly 12.

[0240] In some embodiments, please refer to Figure 3 and Figure 7 , and in combination with other drawings. Among the ends of the housing assembly 12 along the first direction Z, the size of the first fire extinguishing member 13a at the first weld at each end in the second direction X is the first size W1, and the first size W1 ≥ 4 mm, specifically it can be 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, etc.

[0241] With such a setting, the first fire extinguishing member 13a can be as opposed to the first weld along the first direction Z as much as possible, so as to improve the cooling and fire extinguishing effect of the fire extinguishing structure 13 on the weld 123a.

[0242] In some embodiments, please refer to Figure 3 and Figure 7 , and in combination with other drawings. Among the ends of the housing assembly 12 along the first direction Z, the size of the first fire extinguishing member 13a at the first weld at each end in the third direction Y is the second size W2, and the second size W2 ≥ 4 mm, specifically it can be 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, etc.

[0243] In this way, the first fire extinguishing member 13a can be opposite to the first weld seam along the first direction Z as much as possible, so as to improve the cooling and fire extinguishing effect of the fire extinguishing structure 13 on the weld seam 123a.

[0244] In some embodiments, please refer to Figure 3 and Figure 7 together, and in combination with other drawings. The end cover 122 is provided with a pressure relief mechanism 123b. This pressure relief mechanism 123b is the same as the pressure relief mechanism 123b above.

[0245] Among the ends of the housing assembly 12 along the first direction Z, the first fire extinguishing members 13a at the two ends opposite to each other in the second direction X of this end are respectively located on the opposite sides of the pressure relief mechanism 123b in the second direction X, and the first fire extinguishing members 13a on the opposite sides protrude towards the pressure relief mechanism 123b along the second direction X respectively. In this way, the first fire extinguishing member 13a can approach the pressure relief mechanism 123b along the second direction X to perform cooling and fire extinguishing near the pressure relief mechanism 123b.

[0246] In some embodiments, please refer to Figures 8 to 10 together, and in combination with other drawings. In the first direction Z, the outer edge of the part of the housing assembly 12 having the first weld seam extends beyond or is flush with the second fire extinguishing member 13b.

[0247] In this way, on the basis that the second fire extinguishing member 13b can effectively perform the cooling and fire extinguishing function at the first weld seam, the size of the battery cell 10 in the first direction Z can not be increased additionally, and the relatively large energy density of the battery cell 10 can be effectively maintained.

[0248] In some embodiments, please refer to Figure 9 and Figure 10 together, and in combination with other drawings. The third distance H3 ≤ 2 mm, and specifically, it can be 0, 0.5 mm, 1 mm, 1.5 mm, 2 mm, etc.

[0249] In this way, a relatively small assembly tolerance is provided between the second fire extinguishing member 13b and the housing assembly 12.

[0250] In some embodiments, please refer to Figure 9 and Figure 10 together, and in combination with other drawings. The size of the second fire extinguishing member 13b in the first direction Z is the third size W3, and the third size W3 ≥ 4 mm. Specifically, it can be 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, etc.

[0251] In this way, the second fire extinguishing member 13b can be opposite to the first weld seam as much as possible, so as to improve the cooling and fire extinguishing effect of the fire extinguishing structure 13 on the weld seam 123a.

[0252] In some embodiments, please refer to Figures 8 to 10 , and in combination with other drawings. When the number of battery cells 10 is multiple, at least some of the battery cells 10 are sequentially arranged in a direction perpendicular to the first direction Z. Based on this, in the direction perpendicular to the first direction Z, the second fire extinguishing member 13b can be arranged between two adjacent battery cells 10.

[0253] In some embodiments, please refer to Figures 8 to 10 , and in combination with other drawings. In the direction perpendicular to the first direction Z, a heat insulation member 30 is provided between two adjacent battery cells 10.

[0254] In some embodiments, please refer to Figures 8 to 10 , and in combination with other drawings. The heat insulation member 30 and the second fire extinguishing member 13b are sequentially arranged in the first direction Z.

[0255] With such an arrangement, the heat insulation member 30 and the second fire extinguishing member 13b are not stacked in the direction perpendicular to the first direction Z, which can reduce the size of the battery 100 formed by multiple battery cells 10 in the direction perpendicular to the first direction Z, so as to improve the energy density of the battery 100.

[0256] In some embodiments, please refer to Figures 8 to 10 , and in combination with other drawings. In the direction perpendicular to the first direction Z, twice the thickness of the second fire extinguishing member 13b ≤ the thickness of the heat insulation member 30. In this way, the arrangement of the second fire extinguishing member 13b does not additionally increase the size of the battery 100 in the direction perpendicular to the first direction Z, which helps to improve the energy density of the battery 100.

[0257] Wherein, the direction perpendicular to the first direction Z may include the second direction X or the third direction Y.

[0258] In some embodiments, please refer to Figures 11 to 17 , and in combination with other drawings. The battery cell 10 further includes an insulating structure 14, and the insulating structure 14 is arranged between the housing assembly 12 and the electrode assembly 11. The insulating structure 14 is arranged between the electrode assembly 11 and the weld 123a. On the path from the electrode assembly 11 to the weld 123a, at least one fire extinguishing structure 13 arranged at the weld 123a is arranged between the insulating structure 14 and the housing assembly 12.

[0259] Wherein, the insulating structure 14 is arranged between the main part of the electrode assembly 11 and the weld 123a, and specifically can be understood as being arranged between the main body part of the electrode assembly 11 and the weld 123a.

[0260] Wherein, the weld 123a can be the first weld or the second weld.

[0261] The path along which the electrode assembly 11 points to the weld 123a can be considered as the path along which the high-temperature and high-pressure gas and flame generated by the electrode assembly 11 spread towards the weld 123a.

[0262] The insulating structure 14 is disposed between the electrode assembly 11 and the weld 123a, which means that the insulating structure 14 is disposed on the path along which the electrode assembly 11 points to the weld 123a. In this way, the path along which the high-temperature and high-pressure gas and flame generated by the electrode assembly 11 spread towards the weld 123a will pass through the insulating structure 14, specifically through the gap between the insulating structure 14 and the housing assembly 12.

[0263] The insulating structure 14 is disposed between the electrode assembly 11 and the weld 123a. On the path along which the electrode assembly 11 points to the weld 123a, at least one fire extinguishing structure 13 disposed at the weld 123a is disposed between the insulating structure 14 and the housing assembly 12, which means that the insulating structure 14 and at least one fire extinguishing structure 13 are disposed on the path along which the electrode assembly 11 points to the weld 123a, and at least one fire extinguishing structure 13 is disposed between the housing assembly 12 and the insulating structure 14, specifically, at least one fire extinguishing structure 13 is disposed in the gap between the housing assembly 12 and the insulating structure 14.

[0264] Among them, on the path along which the electrode assembly 11 points to the weld 123a, at least one fire extinguishing structure 13 disposed between the insulating structure 14 and the housing assembly 12 can be attached to the inner wall of the housing assembly 12 or can be disposed on the insulating structure 14.

[0265] As an example, as Figures 11 to 17 shown, the insulating structure 14 may include the lower plastic 141 mentioned above.

[0266] With such an arrangement, the path along which the high-temperature and high-pressure gas and flame generated by the electrode assembly 11 spread towards the weld 123a will pass through at least one fire extinguishing structure 13 between the insulating structure 14 and the housing assembly 12, so that at least one fire extinguishing structure 13 can cool down and extinguish the high-temperature and high-pressure gas and flame on the path from the electrode assembly 11 to the weld 123a, thereby reducing the temperature of the high-temperature and high-pressure gas ejected from the weld 123a and extinguishing the flame ejected from the weld 123a, so as to improve the thermal runaway reaction and thermal spread of the battery cell 10, and thus improve the thermal runaway of the battery 100 and enhance the reliability of the battery 100.

[0267] In some embodiments, please refer to Figures 11 to 14, and in combination with other drawings. On the path where the electrode assembly 11 points to the weld 123a, at least one fire extinguishing structure 13 provided between the insulating structure 14 and the housing assembly 12 is the third fire extinguishing member 13c. In the direction perpendicular to the distribution direction of the electrode assembly 11 and the insulating structure 14, the third fire extinguishing member 13c is provided between the insulating structure 14 and the housing assembly 12.

[0268] Among them, the weld 123a can be the first weld or the second weld.

[0269] The distribution direction of the electrode assembly 11 and the insulating structure 14 refers to the distribution direction of the main part of the electrode assembly 11 and the main part of the insulating structure 14, specifically, it can be the distribution direction of the main body part of the electrode assembly 11 and the insulating structure 14.

[0270] For ease of description, it is set that the distribution direction of the electrode assembly 11 and the insulating structure 14 is the distribution direction of the following first wall 1221 and the electrode assembly 11, specifically the first direction Z. That is, the main body part of the electrode assembly 11 and the insulating structure 14 are distributed along the first direction Z. In the first direction Z, the insulating structure 14 is provided between the inner wall of the housing assembly 12 and the main body part. Among them, the direction perpendicular to the first direction Z can be the second direction X or the third direction Y.

[0271] In some possible designs, as Figures 11 to 14 shown, and in combination with other drawings. In the second direction X, a third fire extinguishing member 13c is provided between the insulating structure 14 and the inner wall of the housing assembly 12, so that on the path where the electrode assembly 11 points to the weld 123a, the third fire extinguishing member 13c is provided between the insulating structure 14 and the housing assembly 12.

[0272] In some other possible designs, as Figures 11 to 14 shown, and in combination with other drawings. In the third direction Y, a third fire extinguishing member 13c is provided between the insulating structure 14 and the inner wall of the housing assembly 12, so that on the path where the electrode assembly 11 points to the weld 123a, the third fire extinguishing member 13c is provided between the insulating structure 14 and the housing assembly 12.

[0273] Among them, multiple third fire extinguishing members 13c can be connected to each other or arranged at intervals.

[0274] Among them, as Figures 11 to 13 shown, the third fire extinguishing member 13c can be provided on the insulating structure 14, specifically, it can be attached to the insulating structure 14. As Figure 14 shown, the third fire extinguishing member 13c can be attached to the inner wall of the housing assembly 12, specifically, it can be attached to the inner wall of the housing 121 of the housing assembly 12.

[0275] With such a setting, the third fire extinguishing member 13c can be disposed between the insulating structure 14 and the housing assembly 12 on the path where the electrode assembly 11 points to the weld 123a, so as to effectively cool down and extinguish the high-temperature and high-pressure gas and flame on the path spreading from the electrode assembly 11 to the weld 123a. Thus, the temperature of the high-temperature and high-pressure gas ejected from the weld 123a can be reduced, and the flame ejected from the weld 123a can be extinguished, so as to improve the thermal runaway reaction and thermal spread of the battery cell 10, and thus improve the thermal runaway of the battery 100 and enhance the reliability of the battery 100.

[0276] In some embodiments, please refer to Figures 10 to 13 and other attached drawings in combination. At opposite ends of the insulating structure 14 in the third direction Y, first bosses 1411 are respectively provided, and the first bosses 1411 are used to press against the electrode assembly 11 in the first direction Z.

[0277] Wherein, the third fire extinguishing member 13c can be disposed between the first boss 1411 and the inner wall of the housing assembly 12.

[0278] In some embodiments, please refer to Figures 10 to 13 and other attached drawings in combination. The width of the third fire extinguishing member 13c in the first direction Z is a fourth dimension, and the range of the fourth dimension W4 is 2 mm to 10 mm, and specifically can be 2.2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, etc.

[0279] With such a setting, the fourth fire extinguishing member 13c can perform the function of cooling down and extinguishing fire within a large range.

[0280] In some embodiments, please refer to Figures 10 to 13 and other attached drawings in combination. The fourth dimension W4 of the third fire extinguishing member 13c in the first direction Z ≤ the dimension of the insulating structure 14 in the first direction Z.

[0281] With such a setting, the third fire extinguishing member 13c does not additionally occupy the dimension of the battery cell 10 in the first direction Z.

[0282] In some embodiments, please refer to Figures 10 to 13 and other attached drawings in combination. The dimension of the third fire extinguishing member 13c in the third direction Y, which is located between the housing assembly 12 and the insulating structure 14 along the second direction X, accounts for 70% - 90% of the dimension of the battery cell 10 in the third direction Y, and specifically can be 70%, 75%, 80%, 85%, 90%, 95%, etc.

[0283] Among them, the size of the third fire extinguishing member 13c located between the housing assembly 12 and the insulating structure 14 in the second direction X is the length dimension of the fifth fire extinguishing member 13e.

[0284] In some embodiments, please refer to Figures 10 to 13 , and in combination with other drawings. The size of the third fire extinguishing member 13c located between the housing assembly 12 and the insulating structure 14 in the third direction Y accounts for 70% - 90% of the size of the battery cell 10 in the second direction X, and specifically can be 70%, 75%, 80%, 85%, 90%, 95%, etc.

[0285] Among them, the size of the third fire extinguishing member 13c located between the housing assembly 12 and the insulating structure 14 in the third direction Y is the length dimension of the fifth fire extinguishing member 13e.

[0286] In some embodiments, please refer to Figures 15 to 17 , and in combination with other drawings. The housing assembly 12 is provided with a pressure relief mechanism 123b. This pressure relief mechanism 123b is the same as the pressure relief mechanism 123b above. The pressure relief mechanism 123b and the weld 123a are distributed at intervals. On the path from the electrode assembly 11 pointing to the weld 123a, at least one fire extinguishing structure 13 provided between the insulating structure 14 and the housing assembly 12 is the fourth fire extinguishing member 13d. The fourth fire extinguishing member 13d is provided between the housing assembly 12 and the insulating structure 14, and is provided between the pressure relief mechanism 123b and the weld 123a.

[0287] Among them, the weld 123a can be the first weld or the second weld.

[0288] As an example, the pressure relief mechanism 123b is provided at the end of the housing assembly 12 along the first direction Z. In the first direction Z, the insulating structure 14 is provided between the housing assembly 12 and the main body of the electrode assembly 11, so that in the first direction Z, the insulating structure 14 is also provided between the pressure relief mechanism 123b and the main body. The pressure relief mechanism 123b and the weld 123a are distributed at intervals in a direction perpendicular to the first direction Z. The fourth fire extinguishing member 13d is provided along the first direction Z between the inner wall of the housing assembly 12 having the pressure relief mechanism 123b and the insulating structure 14, and is provided between the pressure relief mechanism 123b and the weld 123a in a direction perpendicular to the first direction Z.

[0289] It should be noted here that during the thermal runaway process of the battery cell 10, the high-temperature and high-pressure gas and flame generated by the battery cell 10 will spread to the pressure relief mechanism 123b through the insulating structure 14, so as to achieve directional pressure relief through the pressure relief mechanism 123b. The fourth fire extinguishing member 13d is disposed between the housing assembly 12 and the insulating structure 14, and is disposed between the pressure relief mechanism 123b and the weld 123a. When the high-temperature and high-pressure gas and flame generated inside the battery cell 10 are released to the pressure relief mechanism 123b through the insulating structure 14, and the overflowing high-temperature and high-pressure gas and flame spread towards the weld 123a, the fourth fire extinguishing member 13d can cool down and extinguish the high-temperature and high-pressure gas and flame, thereby helping to reduce the temperature of the high-temperature and high-pressure gas released from the weld 123a, and extinguishing the flame released from the weld 123a, improving the thermal runaway and thermal spread of the battery cell 10, so as to improve the reliability of the battery 100.

[0290] In some embodiments, please refer to Figures 15 to 17 together with other drawings. The housing assembly 12 includes a housing 121 and an end cap 122. The end cap 122 is disposed at an end of the housing 121 along the first direction Z and encloses a space with the housing 121 for accommodating the electrode assembly 11. A first weld is formed between the housing 121 and the end cap 122, and the weld 123a includes the first weld. The end cap 122 is provided with a pressure relief mechanism 123b. In the first direction Z, the insulating structure 14 is disposed between the end cap 122 and the electrode assembly 11. The fourth fire extinguishing member 13d is disposed between the end cap 122 and the insulating structure 14 along the first direction Z, and is disposed between the pressure relief mechanism 123b and the housing 121 along a direction perpendicular to the first direction Z.

[0291] In the first direction Z, the insulating structure 14 is disposed between the end cap 122 and the electrode assembly 11, and the end cap 122 is provided with a pressure relief mechanism 123b, so that in the first direction Z, the insulating structure 14 is disposed between the pressure relief mechanism 123b and the electrode assembly 11.

[0292] In the first direction Z, the fourth fire extinguishing member 13d is disposed between the end cap 122 and the insulating structure 14, and in a direction perpendicular to the first direction Z, the fourth fire extinguishing member 13d is further disposed between the pressure relief mechanism 123b and the housing 121. Based on the formation of the first weld between the housing 121 and the end cap 122, the fourth fire extinguishing member 13d is disposed between the insulating structure 14 and the first weld.

[0293] As an example, as Figures 15 to 17 shown, together with other drawings. In the first direction Z, the fourth fire extinguishing member 13d is disposed between the end cap 122 and the insulating structure 14, and in the second direction X, the fourth fire extinguishing member 13d is further disposed between the pressure relief mechanism 123b and the housing 121. In this way, the fourth fire extinguishing member 13d is disposed between the insulating structure 14 and the first weld.

[0294] As an example, as Figures 15 to 17 shown and in combination with other attached drawings. In the first direction Z, the fourth fire extinguishing member 13d is disposed between the end cap 122 and the insulating structure 14, and in the third direction Y, the fourth fire extinguishing member 13d is further disposed between the pressure relief mechanism 123b and the housing 121. In this way, the fourth fire extinguishing member 13d is disposed between the insulating structure 14 and the first weld seam.

[0295] By adopting the above technical solution, for the high-temperature and high-pressure gas and flame generated by the electrode assembly 11 and released from the insulating structure 14 to the pressure relief mechanism 123b, during the process of releasing towards the weld seam 123a, the fourth fire extinguishing member 13d can perform targeted temperature reduction and fire extinguishing operations, thereby improving the thermal runaway and thermal spread of the battery cell 10 to enhance the reliability of the battery 100.

[0296] Among them, the third fire extinguishing member 13c and the fourth fire extinguishing member 13d can be connected to each other and can be spaced apart.

[0297] In some embodiments, please refer to Figures 15 to 17 together and in combination with other attached drawings. The insulating structure 14 is provided with a groove 1401. On the path of the electrode assembly 11 pointing to the weld seam 123a, at least one fire extinguishing structure 13 disposed between the insulating structure 14 and the housing assembly 12 is disposed in the groove 1401.

[0298] In some possible designs, as Figures 15 to 17 shown, in the first direction Z, on the side of the insulating structure 14 facing the end cap 122, there is a groove 1401, and the fourth fire extinguishing member 13d is disposed in the groove 1401.

[0299] As an example, as Figures 15 to 17 shown, on the side of the first boss 1411 facing the end cap 122 along the first direction Z, there is a groove 1401, and in the third direction Y, the fourth fire extinguishing member 13d disposed between the pressure relief mechanism 123b and the housing 121 is disposed in the groove 1401 of the first boss 1411.

[0300] As an example, as Figures 15 to 17 shown, the insulating structure 14 is further provided with a second boss 1412 disposed opposite to the pressure relief mechanism 123b along the first direction Z, and the second boss 1412 is used to press against the electrode assembly 11. Moreover, the high-temperature and high-pressure gas and flame generated inside the battery cell 10 can be released to the pressure relief mechanism 123b through the second boss 1412 to perform pressure relief through the pressure relief mechanism 123b. On the side of the second boss 1412 facing the end cap 122 along the first direction Z, there is a groove 1401, and in the second direction X, the fourth fire extinguishing member 13d disposed between the pressure relief mechanism 123b and the housing 121 can be disposed in the groove 1401 of the second boss 1412.

[0301] Such a setting enables at least part of the fire extinguishing structure 13 to effectively achieve the function of cooling and extinguishing fire within the housing assembly 12 without increasing the size of the battery cell 10. In addition, the setting of the groove 1401 can also play a certain limiting role on the fourth fire extinguishing member 13d, to a certain extent ensuring the cooling and extinguishing effect of the fourth fire extinguishing member 13d on the weld 123a.

[0302] In some embodiments, the width of the fourth fire extinguishing member 13d ≥ 2 mm, specifically it can be 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, etc.

[0303] Wherein, in the third direction Y, the dimension of the fourth fire extinguishing member 13d provided between the pressure relief mechanism 123b and the housing 121 in the third direction Y is the width of the fourth fire extinguishing member 13d.

[0304] In the second direction X, the dimension of the fourth fire extinguishing member 13d provided between the pressure relief mechanism 123b and the housing 121 in the second direction X is the width of the fourth fire extinguishing member 13d.

[0305] Such a setting enables the fourth fire extinguishing member 13d to perform the function of cooling and extinguishing fire within a large range.

[0306] In some embodiments, please refer to Figures 14 to 16 and in combination with other drawings. In the third direction Y, the length dimension of the fourth fire extinguishing member 13d provided between the pressure relief mechanism 123b and the housing 121 in the second direction X accounts for 70% - 90% of the dimension of the battery cell 10 in the second direction X, specifically it can be 70%, 75%, 80%, 85%, 90%, 95%, etc.

[0307] In some embodiments, please refer to Figures 14 to 16 and in combination with other drawings. In the second direction X, the length dimension of the fourth fire extinguishing member 13d provided between the pressure relief mechanism 123b and the housing 121 in the third direction Y accounts for 70% - 90% of the dimension of the battery cell 10 in the third direction Y, specifically it can be 70%, 75%, 80%, 85%, 90%, 95%, etc.

[0308] In some embodiments, please refer to Figures 14 to 16 and in combination with other drawings. In the second direction X, the length dimension of the fourth fire extinguishing member 13d provided between the pressure relief mechanism 123b and the housing 121 in the third direction Y accounts for 80% - 120% of the dimension of the pressure relief mechanism 123b in the third direction Y, specifically it can be 80%, 85%, 90%, 95%, 100%, 105%, 110%, 115%, etc.

[0309] With such a setting, the fourth fire extinguishing member 13d can be better positioned close to the pressure relief mechanism 123b to cool and extinguish the fire near the pressure relief mechanism 123b.

[0310] In some embodiments, please refer to Figures 18 to 34 together with other attached drawings. Among them, Figure 26 is Figure 25 a cross-sectional view along L-L, Figure 27 is Figure 26 an enlarged view of M in Figure 28 is Figure 25 a structural diagram of the fire extinguishing structure 13 of the battery cell 10 provided. Figure 29 This is a partial structural diagram of the battery cell 10 provided in some embodiments of the present application, Figure 30 This is a structural diagram of the battery cell 10 provided in some embodiments of the present application. Among them, Figures 25 to 30 the fire extinguishing structure 13 in Figure 31 is a partial exploded view of the battery cell 10 provided in some embodiments of the present application, Figure 32 is Figure 31 a cross-sectional view of the battery cell 10 provided along Figure 31 N-N in Figure 33 is Figure 32 an enlarged view of O in Figure 34 is Figure 31 a structural diagram of the fire extinguishing structure 13 of the battery cell 10 provided. Among them, Figures 31 to 34 the fire extinguishing structure 13 in

[0311] The pressure relief part 1231b is the part of the pressure relief mechanism 123b for performing pressure relief. Specifically, during the thermal runaway process of the battery cell 10, the high-temperature and high-pressure gas and flame inside the battery cell 10 can break through the pressure relief part 1231b, thereby achieving pressure relief.

[0312] The first wall 1221 is a solid wall of the housing assembly 12 having the pressure relief mechanism 123b. Among them, as Figures 18 to 22 and Figures 25 to 34 shown, the first wall 1221 can be provided on the end cover 122 of the housing assembly 12; as Figure 23 and Figure 24 shown, the first wall 1221 can also be provided on the housing 121 of the housing assembly 12.

[0313] The first wall 1221 is connected to the outer periphery of the pressure relief part 1231b. Specifically, the first wall 1221 surrounds the outer periphery of the pressure relief part 1231b and is connected to the pressure relief part 1231b. Among them, the first wall 1221 can be directly connected to the pressure relief part 1231b; or, as Figures 18 to 22 , Figures 25 to 34 shown, the pressure relief mechanism 123b further includes a connection part 1232b. The connection part 1232b surrounds the outer periphery of the pressure relief part 1231b and is connected to the pressure relief part 1231b. The first wall 1221 is connected to the connection part 1232b.

[0314] At least one fire extinguishing structure 13 is provided at the pressure relief part 1231b, which means that at least one fire extinguishing structure 13 is provided at a position where the pressure relief part 1231b can be cooled and extinguished. Among them, at least one fire extinguishing structure 13 provided at the pressure relief part 1231b can be attached to the pressure relief part 1231b; or it can be provided near the pressure relief part 1231b and arranged at an interval from the pressure relief part 1231b. That is, the fire extinguishing structure 13 can be used to cool and extinguish the pressure relief part 1231b, which can be understood as the fire extinguishing structure 13 is provided at the pressure relief part 1231b.

[0315] At least one fire extinguishing structure 13 provided near the pressure relief part 1231b and arranged at an interval from the pressure relief part 1231b can be provided at other positions of the housing assembly 12 except the pressure relief part 1231b. For example, it can be provided on the first wall 1221 of the housing assembly 12, and can also be provided on the housing 121 of the housing assembly 12.

[0316] At least one fire extinguishing structure 13 provided near the pressure relief part 1231b and arranged at an interval from the pressure relief part 1231b can also be provided on the connection part 1232b of the pressure relief mechanism 123b, can also be provided on the lower plastic 141 of the insulation structure 14, and can also be provided on the bottom support plate 142 of the insulation structure 14.

[0317] Among them, at least one fire extinguishing structure 13 provided at the pressure relief part 1231b can be provided outside the housing assembly 12. This fire extinguishing structure 13 can be connected or distributed at intervals with the first fire extinguishing member 13a, or can also be connected or distributed at intervals with the second fire extinguishing member 13b.

[0318] Among them, at least one fire extinguishing structure 13 provided at the pressure relief part 1231b can be provided inside the housing assembly 12. This fire extinguishing structure 13 can be connected or distributed at intervals with the third fire extinguishing member 13c, or can also be connected or distributed at intervals with the fourth fire extinguishing member 13d.

[0319] Based on this, at least one fire extinguishing structure 13 is provided at the pressure relief part 1231b, so that the fire extinguishing structure 13 can cool down and extinguish the fire at the pressure relief part 1231b. In this way, the temperature of the high-temperature and high-pressure gas ejected from the pressure relief part 1231b can be reduced, and the flame ejected from the pressure relief part 1231b can be extinguished. That is, at least one fire extinguishing structure 13 is provided at the pressure relief part 1231b to cool down and extinguish the high-temperature and high-pressure gas and flame ejected from the pressure relief part 1231b, thereby improving the thermal runaway reaction and thermal propagation of the battery cell 10 and enhancing the reliability of the battery 100.

[0320] In some embodiments, the pressure relief part 1231b is separately provided on the first wall 1221. For example, the pressure relief part 1231b can be a pressure valve provided on the first wall 1221.

[0321] In some embodiments, the pressure relief part 1231b is integrally provided on the first wall 1221, and a first breakable mark is provided between the first wall 1221 and the pressure relief part 1231b.

[0322] Among them, the first breakable mark can be a mark such as a notch or a dotted line that is easy to break.

[0323] Based on this, when the battery cell 10 undergoes thermal runaway, the high-temperature and high-pressure gas and flame generated inside the battery cell 10 can break through the pressure relief part 1231b, causing the first breakable mark between the pressure relief part 1231b and the first wall 1212 to break, and further enabling the pressure relief part 1231b to achieve pressure relief.

[0324] In some embodiments, please refer to Figure 18 together with other drawings. The pressure relief mechanism 123b further includes a connecting part 1232b, and the connecting part 1232b is connected to the outer periphery of the pressure relief part 1231b.

[0325] The connecting part 1232b is connected to the first wall 1221. Among them, the connecting part 1232b is integrally provided on the first wall 1221; or, as Figure 18 shown, the connecting part 1232b is separately provided on the first wall 1221.

[0326] In some possible designs, as Figure 18 shown, the pressure relief part 1231b is integrally provided on the connecting part 1232b, and a second breakable mark 1233b is provided between the pressure relief part 1231b and the connecting part 1232b.

[0327] Among them, the second breakable mark 1233b can be a mark such as a notch or a dotted line that is easy to break.

[0328] Based on this, when the battery cell 10 undergoes thermal runaway, the high-temperature and high-pressure gas and flame generated inside the battery cell 10 can break through the pressure relief part 1231b, causing the second breakable mark 1233b between the pressure relief part 1231b and the connection part 1232b to disconnect, thereby enabling the pressure relief part 1231b to achieve pressure relief.

[0329] In some other possible designs, the pressure relief part 1231b is separately provided on the connection part 1232b.

[0330] With such a setting, there can be various types of pressure relief mechanisms 123b, and the design is very flexible.

[0331] In some embodiments, please refer to Figures 18 to 24 , and in combination with other drawings. At least one fire extinguishing structure 13 provided at the pressure relief part 1231b is the fifth fire extinguishing member 13e. The fifth fire extinguishing member 13e is provided with a first through hole 1301. The pressure relief part 1231b is opposite to the first through hole 1301 and is exposed in the first through hole 1301.

[0332] Specifically, in the distribution direction of the first wall 1221 and the electrode assembly 11, the fifth fire extinguishing member 13e is provided with a first through hole 1301 in a penetrating manner. The pressure relief part 1231b is opposite to the first through hole 1301 and is exposed inside the first through hole 1301. In this way, the fifth fire extinguishing member 13e is provided at the pressure relief part 1231b.

[0333] As an example, the distribution direction of the first wall 1221 and the electrode assembly 11 is the first direction Z.

[0334] Among them, the fifth fire extinguishing member 13e can be provided outside the pressure relief part 1231b. The fifth fire extinguishing member 13e can be provided on the first wall 1221, or on the connection part 1232b, or outside the housing assembly 12.

[0335] The fifth fire extinguishing member 13e can also be provided inside the pressure relief part 1231b. The fifth fire extinguishing member 13e can be provided on the first wall 1221, or on the connection part 1232b, or on the pressure relief part 1231b, or on the bottom support plate 142, or on the lower plastic 1411.

[0336] As Figures 18 to 24 shown, and in combination with other drawings. The setting of the first through hole 1301 enables the fifth fire extinguishing member 13e to be generally in an annular structure.

[0337] Among them, as Figures 18 to 22 shown, the fifth fire extinguishing member 13e can be provided on the connection part 1232b, or on the first wall 1221. The fifth fire extinguishing member 13e can be provided on the lower plastic 141 of the insulating structure 14. As Figure 23 andFigure 24 As shown, the fifth fire extinguishing member 13e can be disposed on the bottom plate 142 of the insulating structure 14.

[0338] By adopting the above technical solution, during the thermal runaway process of the battery cell 10, the high-temperature and high-pressure gas and flame generated by the battery cell 10 can break through the pressure relief portion 1231b of the pressure relief mechanism 123b to be discharged outside the battery cell 10 through the pressure relief portion 1231b, and the fifth fire extinguishing member 13e disposed at the pressure relief portion 1231b can cool down and extinguish the high-temperature and high-pressure gas and flame. Moreover, during the process of the high-temperature and high-pressure gas and flame breaking through the pressure relief portion 1231b, it can also pass through the first through hole 1301, thereby improving the problem that the fifth fire extinguishing member 13e blocks the high-temperature and high-pressure gas and flame, which is conducive to the release of the high-temperature and high-pressure gas and flame. Therefore, the thermal runaway reaction and thermal propagation problems of the battery cell 10 can be improved, thereby improving the thermal runaway of the battery 100 to enhance the reliability of the battery 100.

[0339] In some embodiments, please refer to Figures 18 to 24 together and in combination with other drawings. In the direction perpendicular to the penetration direction of the first through hole 1301, the size of the fifth fire extinguishing member 13e is larger than the size of the pressure relief portion 1231b, and the ratio of the size of the first through hole 1301 to the size of the pressure relief portion 1231b is ≥0.8 and ≤1.2.

[0340] Among them, the penetration direction of the first through hole 1301 is substantially parallel to the distribution direction of the first wall 1221 and the electrode assembly 11.

[0341] For the convenience of description, the distribution direction of the first wall 1221 and the electrode assembly 11 is set as the first direction Z. That is, in the direction perpendicular to the first direction Z, the size of the fifth fire extinguishing member 13e is larger than the size of the pressure relief portion 1231b, and the ratio of the size of the first through hole 1301 to the size of the pressure relief portion 1231b is ≥0.8 and ≤1.2.

[0342] As an example, as Figures 18 to 22 shown and in combination with other drawings. The direction perpendicular to the first direction Z may include the second direction X. In the second direction X, the size of the fifth fire extinguishing member 13e is the fifth size W5, the size of the first through hole 1301 is the sixth size W6, and the size of the pressure relief portion 1231b is the seventh size W7. Among them, the fifth size W5 is larger than the seventh size W7, and 0.8 ≤ sixth size W6 / seventh size W7 ≤ 1.2, specifically, it can be 0.8, 0.85, 0.9, 0.95, 1, 1.05, 1.1, 1.15, etc.

[0343] As an embodiment, as Figures 18 to 22As shown and in combination with other attached drawings. The direction perpendicular to the first direction Z may include the third direction Y, and the second direction X is perpendicular to the third direction Y. In the third direction Y, the size of the fifth fire extinguishing member 13e is the eighth size W8, the size of the first through hole 1301 is the ninth size W9, and the size of the pressure relief portion 1231b is the tenth size W10. Among them, the eighth size W8 is greater than the tenth size W10, and 0.8 ≤ the ninth size W9 / the tenth size W10 ≤ 1.2. Specifically, it can be 0.8, 0.85, 0.9, 0.95, 1, 1.05, 1.1, 1.15, etc.

[0344] Since the size of the fifth fire extinguishing member 13e is greater than the size of the pressure relief portion 1231b, the fifth fire extinguishing member 13e can be disposed on at least one of the connecting portion 1232b, the first wall 1221, and the insulating structure 14. In this way, during the process of the pressure relief portion 1231b being broken through, the position of the fifth fire extinguishing member 13e can be maintained, so as to continuously cool and extinguish the high-temperature and high-pressure gas and flame, thereby helping to improve the thermal runaway reaction and thermal propagation problems of the battery cell 10 and improving the reliability of the battery 100.

[0345] Since the ratio of the size of the first through hole 1301 to the size of the pressure relief portion 1231b is ≥ 0.8 and ≤ 1.2, the size of the first through hole 1301 can be within a more appropriate range. On the one hand, the first through hole 1301 can effectively pass the high-temperature and high-pressure gas and flame without affecting the exhaust of the pressure relief mechanism 123b. On the other hand, the fifth fire extinguishing member 13e can effectively contact the high-temperature and high-pressure gas and flame to play a sufficient role in cooling and extinguishing.

[0346] In some embodiments, a second breakable mark 1233b is provided between the pressure relief portion 1231b and the connecting portion 1232b, facilitating the pressure relief portion 1231b to be broken through under the action of high temperature and high pressure to achieve pressure relief.

[0347] In some embodiments, in the direction perpendicular to the first direction Z, the difference range between the size of the fifth fire extinguishing member 13e and the size of the first through hole 1301 is 2 mm to 40 mm. Specifically, it can be 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, etc.

[0348] For example, the difference range between the fifth size W5 and the sixth size W6 is 2 mm to 40 mm.

[0349] For example, the difference range between the eighth size W8 and the ninth size W9 is 2 mm to 40 mm.

[0350] With such a setting, the fifth fire extinguishing member 13e has a large area to contact the high-temperature and high-pressure gas and flame to play an effective role in cooling and extinguishing.

[0351] In some embodiments, the distance between the fifth fire extinguishing member 13e and the pressure relief portion 1231b in the first direction Z is ≤ 5 mm, specifically, it can be 4 mm, 3 mm, 2 mm, 1 mm, 0, etc.

[0352] With such a setting, the fifth fire extinguishing member 13e can effectively cool down and extinguish the fire near the pressure relief mechanism 123b.

[0353] In some embodiments, please refer to Figures 25 to 30 , and in combination with other drawings. At least one fire extinguishing structure 13 provided at the pressure relief portion 1231 is the sixth fire extinguishing member 13f. The sixth fire extinguishing member 13f includes a first fire extinguishing portion 131f and a second fire extinguishing portion 132f, and the second fire extinguishing portion 132f is connected to the outer periphery of the first fire extinguishing portion 131f. The first fire extinguishing portion 131f is configured to move relative to the second fire extinguishing portion 132f for pressure relief. Along the distribution direction of the first wall 1221 and the electrode assembly 11, the first fire extinguishing portion 131f and the pressure relief portion 1231b are disposed opposite to each other.

[0354] The first fire extinguishing portion 131f and the second fire extinguishing portion 132f are two parts of the sixth fire extinguishing member 13f, both having the function of cooling down and extinguishing the fire.

[0355] The second fire extinguishing portion 132f surrounds the outer periphery of the first fire extinguishing portion 131f and is connected to the first fire extinguishing portion 131f.

[0356] Wherein, the first fire extinguishing portion 131f can be disposed outside the pressure relief portion 1231b. At this time, the second fire extinguishing portion 132f is located outside the first wall 1221 and can be connected to the first wall 1221, or can be connected to the connecting portion 1232b, or can also be connected to other positions.

[0357] The first fire extinguishing portion 131f can also be disposed inside the pressure relief portion 1231b. At this time, the second fire extinguishing portion 132f is located inside the housing assembly 12 and can be connected to the first wall 1221, or can be connected to the connecting portion 1232b, or can also be connected to the lower plastic 141 of the insulating structure 14, or can also be connected to the bottom plate 142 of the insulating structure 14.

[0358] As an example, as Figures 25 to 30 shown, the sixth fire extinguishing member 13f is disposed outside the pressure relief portion 1231b, and the second fire extinguishing portion 132f is connected to the first wall 1221.

[0359] As an example, as Figure 29 and Figure 30 shown, the second fire extinguishing portion 132f of the sixth fire extinguishing member 13f is connected to the first fire extinguishing member 13a.

[0360] During the thermal runaway process of the battery cell 10, the high-temperature and high-pressure gas and flame generated inside the battery cell 10 can break through the pressure relief part 1231b and the first fire extinguishing part 131f, thereby achieving pressure relief. Moreover, the second fire extinguishing part 132f and the first fire extinguishing part 131f can cool down and extinguish the high-temperature and high-pressure gas and flame, and contribute to exhaust, which can improve the thermal runaway reaction and thermal propagation of the battery cell 10, so as to improve the thermal runaway problem of the battery 100 and enhance the reliability of the battery 100.

[0361] In some embodiments, please refer to Figures 25 to 30 together and in combination with other drawings. Along the distribution direction of the first wall 1221 and the electrode assembly 11, the first fire extinguishing part 131f is arranged on the side of the pressure relief part 1231b away from the electrode assembly 11.

[0362] By arranging the first fire extinguishing part 131f on the side of the pressure relief part 1231b away from the electrode assembly 11, the first fire extinguishing part 131f is arranged outside the pressure relief part 1231b. In this way, it can improve the problem that the sixth fire extinguishing member 13f blocks the high-temperature and high-pressure gas and flame from passing through the pressure relief part 1231b for pressure relief inside the pressure relief part 1231b, which helps to improve the pressure relief of the battery cell 10 and can improve the thermal runaway reaction of the battery cell 10.

[0363] In some embodiments, please refer to Figures 25 to 30 together and in combination with other drawings. A third easily breakable mark 133f is provided between the first fire extinguishing part 131f and the second fire extinguishing part 132f.

[0364] Among them, the third easily breakable mark 133f can be a mark such as a notch or a dotted line that is easy to break.

[0365] Based on this, when the battery cell 10 undergoes thermal runaway, during the process that the high-temperature and high-pressure gas and flame generated inside the battery cell 10 break through the pressure relief part 1231b, the first fire extinguishing part 131f will also be broken through, causing the third easily breakable mark 133f between the first fire extinguishing part 131f and the second fire extinguishing part 132f to break, improving the problem that the first fire extinguishing part 131f blocks the release of the high-temperature and high-pressure gas and flame, which helps to improve the thermal runaway reaction of the battery cell 10. With such a setting, it is beneficial for the high-temperature and high-pressure gas and flame inside the battery cell 10 to break through the first fire extinguishing part 131f without affecting the exhaust effect.

[0366] In some embodiments, please refer to Figure 18 and Figure 28 together and in combination with other drawings. In the direction perpendicular to the distribution direction of the first wall 1221 and the electrode assembly 11, the size of the second fire extinguishing part 132f is larger than the size of the pressure relief part 1231b, and the ratio of the size of the pressure relief part 1231b to the size of the first fire extinguishing part 131f is ≥0.8 and ≤1.2.

[0367] For ease of description, the distribution directions of the first wall 1221 and the electrode assembly 11 are set as the first direction Z.

[0368] As an example, such as Figure 18 and Figure 28 , and in combination with other drawings. The direction perpendicular to the first direction Z may include the second direction X. In the second direction X, the size of the first fire extinguishing part 131f is the eleventh size W11, and the size of the second fire extinguishing part 132f is the twelfth size W12. Among them, the twelfth size W12 is greater than the seventh size W7, and 0.8 ≤ the seventh size W7 / the eleventh size W11 ≤ 1.2. The seventh size W7 / the eleventh size W11 may specifically be 0.8, 0.85, 0.9, 0.95, 1, 1.05, 1.1, 1.15, etc.

[0369] As an example, such as Figure 18 and Figure 28 shown, and in combination with other drawings. The direction perpendicular to the first direction Z may include the third direction Y. In the third direction Y, the size of the first fire extinguishing part 131f is the thirteenth size W13, and the size of the second fire extinguishing part 132f is the fourteenth size W14. Among them, the fourteenth size W14 is greater than the tenth size W10, and 0.8 ≤ the tenth size W10 / the thirteenth size W13 ≤ 1.2. The tenth size W10 / the thirteenth size W13 may specifically be 0.8, 0.85, 0.9, 0.95, 1, 1.05, 1.1, 1.15, etc.

[0370] By setting the size of the second fire extinguishing part 132f to be greater than the size of the pressure relief part 1231b, the second fire extinguishing part 132f can be connected to at least one of the connecting part 1232b, the first wall 1221, and the insulating structure 14. In this way, during the process of the pressure relief part 1231b and the first fire extinguishing part 131f being broken through, the position of the second fire extinguishing part 132f can be maintained, so as to continuously cool and extinguish the high-temperature and high-pressure gas and flame, thereby helping to improve the thermal runaway reaction of the battery cell 10.

[0371] By setting the ratio of the size of the pressure relief part 1231b to the size of the first fire extinguishing part 131f ≥ 0.8 and ≤ 1.2, the size of the first fire extinguishing part 131f can be within a more appropriate range. On the one hand, the first fire extinguishing part 131f can effectively cool and extinguish the high-temperature and high-pressure gas, flame, etc. breaking through the pressure relief part 1231b. On the other hand, the first fire extinguishing part 131f will not overly block and affect the release of the high-temperature and high-pressure gas, flame, etc. In this way, the thermal runaway reaction of the battery cell 10 can be effectively improved.

[0372] In some embodiments, please refer to Figure 30, and in combination with other drawings. The first fire extinguishing part 131f is provided with a second through hole 1302 opposite to the pressure relief part 1231b.

[0373] Understandably, the first fire extinguishing part 131f is provided with a second through hole 1302 penetrating along the first direction Z.

[0374] With such a setting, when the high-temperature and high-pressure gas and flame inside the battery cell 10 break through the pressure relief part 1231b, they can be exhausted through the second through hole 1302. In this way, the battery cell 10 has a better exhaust effect, which helps to improve the thermal runaway reaction of the battery cell 10.

[0375] In some embodiments, please refer to Figures 31 to 34 , and in combination with other drawings. At least one fire extinguishing structure 13 provided at the pressure relief part 1231b is a seventh fire extinguishing member 13g. Along the distribution direction of the first wall 1221 and the electrode assembly 11, the seventh fire extinguishing member 13g is provided on the side of the pressure relief part 1231b facing the electrode assembly 11 and is arranged opposite to the pressure relief part 1231b.

[0376] By providing the seventh fire extinguishing member 13g, the seventh fire extinguishing member 13g can cool and extinguish the high-temperature and high-pressure gas and flame during the process of releasing the high-temperature and high-pressure gas and flame inside the battery cell 10 to the pressure relief part 1231b, thereby improving the thermal runaway and thermal spread of the battery cell 10.

[0377] Among them, the seventh fire extinguishing member 13g can be provided on the pressure relief part 1231b or on the lower plastic 141 of the insulating structure 14.

[0378] In some embodiments, please refer to Figures 31 to 34 , and in combination with other drawings. The seventh fire extinguishing member 13g is connected to the pressure relief part 1231b and is used to move with the pressure relief part 1231b.

[0379] By adopting the above technical solution, during the thermal runaway process of the battery cell 10, when the high-temperature and high-pressure gas and flame generated inside the battery cell 10 break through the pressure relief part 1231b, the seventh fire extinguishing member 13g will move with the pressure relief part 1231b, which is beneficial to the release of the high-temperature and high-pressure gas and flame. Moreover, the seventh fire extinguishing member 13g moves with the pressure relief part 1231b, and can continuously perform the cooling and extinguishing operation, thereby efficiently improving the thermal runaway reaction and thermal spread problem of the battery cell 10, improving the thermal runaway problem of the battery 100, and enhancing the reliability of the battery 100.

[0380] In some embodiments, please refer to Figures 31 to 34 , and in combination with other drawings. In the distribution direction of the first wall 1221 and the electrode assembly 11, the projection of the seventh fire extinguishing member 13g is located within the projection of the pressure relief part 1231b.

[0381] In the distribution direction of the first wall 1221 and the electrode assembly 11, the projection of the seventh fire extinguishing member 13g refers to the projection of the seventh fire extinguishing member 13g on a projection plane perpendicular to the distribution direction of the first wall 1221 and the electrode assembly 11. In the distribution direction of the first wall 1221 and the electrode assembly 11, the projection of the pressure relief portion 1231b refers to the projection of the pressure relief portion 1231b on a projection plane perpendicular to the distribution direction of the first wall 1221 and the electrode assembly 11.

[0382] For the convenience of description, the distribution direction of the first wall 1221 and the electrode assembly 11 is set as the first direction Z. Among them, the direction perpendicular to the first direction Z may include the second direction X or the third direction Y.

[0383] In the distribution direction of the first wall 1221 and the electrode assembly 11, that the projection of the seventh fire extinguishing member 13g is located within the projection of the pressure relief portion 1231b means that the outer contour of the projection of the pressure relief portion 1231b surrounds the outer periphery of the projection of the seventh fire extinguishing member 13g. Specifically, in the direction perpendicular to the first direction Z, the size of the pressure relief portion 1231b is larger than the size of the seventh fire extinguishing member 13g.

[0384] As an example, such as Figure 18 and Figure 34 , and in combination with other drawings. In the second direction X, the size of the seventh fire extinguishing member 13g is the fifteenth dimension W15, and the fifteenth dimension W15 is smaller than the seventh dimension W7 of the pressure relief portion 1231b.

[0385] As an example, such as Figure 18 and Figure 34 , and in combination with other drawings. In the third direction Y, the size of the seventh fire extinguishing member 13g is the sixteenth dimension W16, and the sixteenth dimension W16 is smaller than the tenth dimension W10 of the pressure relief portion 1231b.

[0386] By adopting the above technical solution, it is ensured that the seventh fire extinguishing member 13g will not affect the movement of the pressure relief portion 1231b relative to the first wall 1221 as much as possible, so that high-temperature and high-pressure gases, flames, etc. can smoothly break through the pressure relief portion 1231b without being affected by the seventh fire extinguishing member 13g, and the seventh fire extinguishing member 13g can continuously cool down and extinguish fires, which helps to improve the thermal runaway reaction and thermal propagation problems of the battery cell 10.

[0387] It should be supplemented here that the seventh fire extinguishing member 13g is spaced apart from the sixth fire extinguishing member 13f, the fifth fire extinguishing member 13e, the fourth fire extinguishing member 13d, the third fire extinguishing member 13c, the second fire extinguishing member 13b, and the first fire extinguishing member 13a, which is convenient for the seventh fire extinguishing member 13g to move with the pressure relief portion 1231b.

[0388] In some embodiments, please refer to Figures 31 to 34 and other attached drawings in combination. The seventh fire extinguishing member 13g is provided with a third through hole opposite to the pressure relief portion 1231b.

[0389] It can be understood that the seventh fire extinguishing member 13g is provided with a third through hole penetrating along the distribution direction of the first wall 1221 and the electrode assembly 11, that is, the seventh fire extinguishing member 13g is provided with a third through hole penetrating along the first direction Z.

[0390] With such a setting, the seventh fire extinguishing member 13g has a better exhaust effect, and can effectively improve the thermal runaway reaction of the battery cell 10.

[0391] In some embodiments, the housing assembly 12 further includes a second wall 1211 connected to the first wall 1221. At least one fire extinguishing structure 13 provided at the pressure relief portion 1231b abuts against the second wall 1211, and the second wall 1211 is the wall with the largest area among all the walls of the housing assembly 12.

[0392] Wherein, the second wall 1211 is a solid wall of the housing assembly 12. The housing 121 of the housing assembly 12 may be provided with the second wall 1211, and the end cover 122 of the housing assembly 12 may also be provided with the second wall 1211.

[0393] It can be understood that at least one fire extinguishing structure 13 provided at the pressure relief portion 1231b abuts against the position of the second wall 1211 close to the pressure relief portion 1231b. As an example, the pressure relief portion 1231b is provided at one end of the housing assembly 12 along the first direction Z, and at least one fire extinguishing structure 13 provided at the pressure relief portion 1231b abuts against the end of the second wall 1211 close to the pressure relief portion 1231b along the first direction Z.

[0394] By arranging at least one fire extinguishing structure 13 provided at the pressure relief portion 1231b to abut against the wall with the largest area among all the walls of the housing assembly 12, the fire extinguishing structure 13 can be better close to the pressure relief portion 1231b, so as to effectively cool and extinguish the high-temperature and high-pressure gas and flame at the pressure relief portion 1231b.

[0395] In some embodiments, please refer to Figures 31 to 34 and other attached drawings in combination. The effective area of the orthographic projection of the seventh fire extinguishing member 13g on the pressure relief portion 1231b accounts for more than 40% of the area of the pressure relief portion 1231b.

[0396] The orthographic projection of the seventh fire extinguishing member 13g on the pressure relief portion 1231b refers to the projection of the seventh fire extinguishing member 13g projected onto the pressure relief portion 1231b along the first direction Z.

[0397] The effective area of the orthographic projection of the seventh fire extinguishing member 13g on the pressure relief part 1231b refers to the area of the part of the orthographic projection of the seventh fire extinguishing member 13g on the pressure relief part 1231b excluding the third through hole.

[0398] The effective area of the orthographic projection of the seventh fire extinguishing member 13g on the pressure relief part 1231b accounts for more than 40% of the area of the pressure relief part 1231b, and can be, for example, 40%, 45%, 50%, 55%, 60%, 65%, 70%, etc.

[0399] With such a setting, the seventh fire extinguishing member 13g has a relatively large area in contact with the high-temperature and high-pressure gas and the flame, so as to effectively cool down and extinguish the fire, thereby improving the thermal runaway reaction of the battery cell 10.

[0400] In some embodiments, the fire extinguishing structure 13 includes a core for extinguishing fire and a shell for encapsulating the core.

[0401] With such a setting, when the fire extinguishing structure 13 is in a high-temperature environment, the shell of the fire extinguishing structure 13 ruptures, and the core in the shell can reduce the temperature of the high-temperature and high-pressure gas and extinguish the flame, so as to achieve the effect of cooling down and extinguishing the fire.

[0402] In some embodiments, the core is a perfluoromethyl hexanone core.

[0403] The perfluoromethyl hexanone core refers to a core made of perfluoromethyl hexanone material.

[0404] With such a setting, when the fire extinguishing structure 13 is in a high-temperature environment and the shell of the fire extinguishing structure 13 ruptures, the perfluoromethyl hexanone material of the perfluoromethyl hexanone core can decompose into fluorine, oxygen and carbon atoms at high temperature. These atoms can undergo free radical reactions with hydrogen in the high-temperature and high-pressure gas and the flame to obtain stable compounds, thereby effectively suppressing the spread of the flame. Moreover, the heat can be carried away during the decomposition process of the perfluoromethyl hexanone material to reduce the temperature of the high-temperature and high-pressure gas and the flame, thereby suppressing the generation of the flame. Therefore, the fire extinguishing structure 13 can suppress the generation and spread of the flame and achieve the effect of cooling down and extinguishing the fire.

[0405] In some embodiments, the shell is a polymer shell.

[0406] The polymer shell refers to a shell made of polymer material. Among them, the polymer material can include one or more of polyester, polyurethane, phenolic resin, urea formaldehyde resin, polyurea resin, polymer silicon, natural source polymer, acrylic resin, and epoxy resin.

[0407] The setting of the polymer shell enables the shell to play a certain protective role for the core and rupture in a high-temperature environment, so that the core can perform the operation of cooling down and extinguishing the fire.

[0408] In some embodiments, the fire extinguishing structure 13 includes microcapsules, and the microcapsules include the above-mentioned capsule shell and the above-mentioned core.

[0409] In some embodiments, the number of microcapsules is multiple, and the multiple microcapsules can be fixed by a polymer adhesive or other adhesives.

[0410] Specifically, the polymer adhesive fixes the capsule shells of the multiple microcapsules.

[0411] In some embodiments, the multiple microcapsules can form a fire extinguishing layer of the fire extinguishing structure 13. The fire extinguishing structure 13 may further include an adhesive layer, and the adhesive layer is disposed on the fire extinguishing layer and is used for adhesion.

[0412] In some embodiments, the fire extinguishing structure 13 may further include a substrate, and the microcapsules may be disposed on a coating of the substrate to form a fire extinguishing layer.

[0413] In some embodiments, in the fire extinguishing structure 13, the weight ratio range of perfluoromethylcyclohexanone to the polymer material is 20% to 90%, and specifically, it may be 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, etc.

[0414] With such a setting, the fire extinguishing structure 13 has a relatively large content of perfluoromethylcyclohexanone, thereby having a better cooling and fire extinguishing effect.

[0415] In some embodiments, in the fire extinguishing structure 13, the weight ratio range of perfluoromethylcyclohexanone to the polymer material is 50% to 85%, and specifically, it may be 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, etc.

[0416] In some embodiments, the overall thickness range of the fire extinguishing structure 13 is 0.2 mm to 10 mm, that is, the sum of the thicknesses of the fire extinguishing layer and the adhesive layer ranges from 0.2 mm to 10 mm, and specifically, it may be 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 0.7 mm, 0.75 mm, 0.8 mm, 0.9 mm, etc.

[0417] In some embodiments, the thickness range of the fire extinguishing layer is 0.2 mm to 0.45 mm, and specifically, it may be 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, etc.

[0418] With such a setting, the fire extinguishing layer has a more appropriate thickness, thereby enabling the fire extinguishing structure 13 to have a smaller volume and a better fire extinguishing effect.

[0419] In some embodiments, the thickness of the adhesive layer ranges from 0.02 mm to 2 mm, and specifically may be 0.05 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.3 mm, 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.3 mm, 1.5 mm, 1.8 mm, etc.

[0420] In some embodiments, the thickness of the fire extinguishing structure 13 ranges from 0.3 mm to 3 mm, and specifically may be 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, etc.

[0421] Please refer to Figure 2 , and in combination with other drawings. The battery 100 provided in the embodiments of the present application includes battery cells 10. Among them, the battery cell 10 in this embodiment is the same as the battery cell 10 in the previous embodiment. For specific details, please refer to the relevant description of the battery cell 10 in the previous embodiment, which will not be elaborated here.

[0422] By adopting the battery cell 10 involved above, the battery 100 provided in the embodiments of the present application can improve the problem of thermal runaway of the entire battery 100 and improve the reliability of the battery 100.

[0423] Please refer to Figure 1 , the electrical device provided in the embodiments of the present application includes a battery 100. Among them, the battery 100 in this embodiment is the same as the battery 100 in the previous embodiment. For specific details, please refer to the relevant description of the battery 100 in the previous embodiment, which will not be elaborated here.

[0424] By adopting the battery 100 involved above, the electrical device provided in the embodiments of the present application can improve the reliability of the battery 100, and further improve the reliability of the electrical device.

[0425] As one of the embodiments of the present application, as Figures 3 to 6 shown, the battery cell 10 includes a housing assembly 12, an electrode assembly 11, and a fire extinguishing structure 13. The housing assembly 12 includes a housing 121 and an end cap 122, and the end cap 122 is provided at the end of the housing 121 along the first direction Z. Weld seams 123a are respectively formed between the two opposite end portions of the end cap 122 along the second direction X and between the two opposite end portions of the end cap 122 along the third direction Y and the housing 121. The electrode assembly 11 is disposed in the internal environment defined by the housing 121 and the end cap 122. At least one fire extinguishing structure 13 is disposed on the surface of the weld seam 123a away from the electrode assembly 11 along the first direction Z.

[0426] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery cell, characterized in that, Comprising: A housing assembly; An electrode assembly disposed within the housing assembly; A fire extinguishing structure; The housing assembly forms a weld seam, and at least one of the fire extinguishing structures is disposed at the weld seam; and / or, the housing assembly is provided with a pressure relief mechanism, and at least one of the fire extinguishing structures is disposed at the pressure relief mechanism.

2. The battery cell according to claim 1, characterized in that, At least one of the fire extinguishing structures disposed at the weld seam abuts against the housing assembly; And / or, at least one of the fire extinguishing structures disposed at the pressure relief mechanism abuts against the housing assembly; And / or, the battery cell further includes an insulating structure disposed between the housing assembly and the electrode assembly, and at least one of the fire extinguishing structures disposed at the weld seam is disposed on the insulating structure; And / or, the battery cell further includes an insulating structure disposed between the housing assembly and the electrode assembly, and at least one of the fire extinguishing structures disposed at the pressure relief mechanism is disposed on the insulating structure.

3. The battery cell according to claim 1, wherein The housing assembly includes a housing and an end cap, the end cap is disposed on the housing, and together with the housing encloses a space for accommodating the electrode assembly; A first weld seam is formed between the housing and the end cap, the weld seam includes the first weld seam, and at least one of the fire extinguishing structures is disposed at the first weld seam; and / or, the housing forms a second weld seam, the weld seam includes the second weld seam, and at least one of the fire extinguishing structures is disposed at the second weld seam.

4. The battery cell according to claim 3, wherein The end cap is disposed at an end of the housing along a first direction; At least one of the fire extinguishing structures disposed at the first weld seam is a first fire extinguishing member, the first fire extinguishing member abuts against an outer wall of the housing assembly along the first direction, and in a projection plane perpendicular to the first direction, along the width direction of the first weld seam, the distance between the outer edge of the housing assembly and the first fire extinguishing member is ≤6 mm; and / or, at least one of the fire extinguishing structures disposed at the first weld seam is a second fire extinguishing member, the second fire extinguishing member abuts against an outer wall of the housing assembly along a direction perpendicular to the first direction, and along the first direction, the distance between the outer edge of the housing assembly and the second fire extinguishing member is ≤6 mm.

5. The battery cell according to claim 1, characterized in that, At least one of the fire extinguishing structures disposed at the weld seam abuts against the surface of the weld seam.

6. The battery cell according to claim 1, wherein The battery cell further includes an insulating structure disposed between the housing assembly and the electrode assembly, the insulating structure is disposed between the electrode assembly and the weld seam; on the path from the electrode assembly pointing to the weld seam, at least one of the fire extinguishing structures disposed at the weld seam is disposed between the insulating structure and the housing assembly.

7. The battery cell according to claim 6, wherein, On the path from the electrode assembly pointing to the weld seam, at least one of the fire extinguishing structures disposed between the insulating structure and the housing assembly is a third fire extinguishing member; in a direction perpendicular to the distribution direction of the electrode assembly and the insulating structure, the third fire extinguishing member is disposed between the insulating structure and the housing assembly.

8. The battery cell according to claim 6, wherein, The housing assembly is provided with a pressure relief mechanism spaced from the weld seam; on the path of the electrode assembly pointing to the weld seam, at least one of the fire extinguishing structures provided between the insulating structure and the housing assembly is a fourth fire extinguishing member; the fourth fire extinguishing member is provided between the housing assembly and the insulating structure, and between the pressure relief mechanism and the weld seam.

9. The battery cell according to claim 8, wherein, The housing assembly includes a housing and an end cover. The end cover is provided at an end of the housing along a first direction to enclose a space for accommodating the electrode assembly with the housing; a first weld seam is formed between the housing and the end cover, and the weld seam includes the first weld seam; the end cover is provided with the pressure relief mechanism; in the first direction, the insulating structure is provided between the end cover and the electrode assembly; the fourth fire extinguishing member is provided between the end cover and the insulating structure along the first direction, and between the pressure relief mechanism and the housing along a direction perpendicular to the first direction.

10. The battery cell according to claim 6, characterized in that, The insulating structure is provided with a groove, and on the path of the electrode assembly pointing to the weld seam, at least one of the fire extinguishing structures provided between the insulating structure and the housing assembly is provided in the groove.

11. The battery cell according to any one of claims 1-10, characterized in that, The housing assembly includes a first wall and the pressure relief mechanism. The pressure relief mechanism includes a pressure relief portion, and the first wall is connected to the outer periphery of the pressure relief portion, and at least one of the fire extinguishing structures is provided at the pressure relief portion.

12. The battery cell according to claim 11, characterized in that, The pressure relief portion is provided on the first wall in a split manner; Alternatively, the pressure relief portion is integrally provided on the first wall, and a first weakening line is provided between the first wall and the pressure relief portion; Alternatively, the pressure relief mechanism further includes a connecting portion connected to the first wall, and the pressure relief portion is provided on the connecting portion in a split manner; Alternatively, the pressure relief mechanism further includes a connecting portion connected to the first wall, the pressure relief portion is integrally provided on the connecting portion, and a second weakening line is provided between the pressure relief portion and the connecting portion.

13. The battery cell according to claim 11, wherein, At least one of the fire extinguishing structures provided at the pressure relief portion is a fifth fire extinguishing member. The fifth fire extinguishing member is provided with a first through hole, and the pressure relief portion is opposite to the first through hole and exposed to the first through hole.

14. The battery cell according to claim 13, wherein In a direction perpendicular to the through direction of the first through hole, the size of the fifth fire extinguishing member is larger than the size of the pressure relief portion, and the ratio of the size of the first through hole to the size of the pressure relief portion is ≥0.8 and ≤1.

2.

15. The battery cell according to claim 11, characterized in that, At least one of the fire extinguishing structures provided at the pressure relief portion is a sixth fire extinguishing member. The sixth fire extinguishing member includes a first fire extinguishing portion and a second fire extinguishing portion connected to the outer periphery of the first fire extinguishing portion. The first fire extinguishing portion is used to move relative to the second fire extinguishing portion to relieve pressure; along the distribution direction of the first wall and the electrode assembly, the first fire extinguishing portion is disposed opposite to the pressure relief portion.

16. The battery cell according to claim 15, wherein, Along the distribution direction of the first wall and the electrode assembly, the first fire extinguishing portion is disposed on a side of the pressure relief portion away from the electrode assembly.

17. The battery cell according to claim 15, characterized in that, A third weakening line is provided between the first fire extinguishing portion and the second fire extinguishing portion.

18. The battery cell according to claim 15, characterized in that In a direction perpendicular to the distribution direction of the first wall and the electrode assembly, the size of the second fire extinguishing portion is greater than the size of the pressure relief portion, and the ratio of the size of the pressure relief portion to the size of the first fire extinguishing portion is ≥ 0.8 and ≤ 1.

2.

19. The battery cell according to claim 15, characterized in that, The first fire extinguishing portion is provided with a second through hole opposite to the pressure relief portion.

20. The battery cell according to claim 11, wherein At least one of the fire extinguishing structures provided at the pressure relief portion is a seventh fire extinguishing member. Along the distribution direction of the first wall and the electrode assembly, the seventh fire extinguishing member is provided on the side of the pressure relief portion facing the electrode assembly and is disposed opposite to the pressure relief portion.

21. The battery cell according to claim 20, wherein, The seventh fire extinguishing member is connected to the pressure relief portion and is configured to move with the pressure relief portion.

22. The battery cell according to claim 20, wherein, In the distribution direction of the first wall and the electrode assembly, the projection of the seventh fire extinguishing member is located within the projection of the pressure relief portion.

23. The battery cell according to claim 20, wherein The seventh fire extinguishing member is provided with a third through hole opposite to the pressure relief portion.

24. The battery cell according to claim 11, wherein, The housing assembly further includes a second wall connected to the first wall. At least one of the fire extinguishing structures provided at the pressure relief portion abuts against the second wall, and the second wall is the wall with the largest area among all the walls of the housing assembly.

25. The battery cell according to any one of claims 1-10, characterized in that, The fire extinguishing structure includes a core for extinguishing fire and a shell for encapsulating the core.

26. The battery cell according to claim 25, wherein, The core is a perfluoroketone core; and / or, the shell is a polymer shell.

27. A battery, characterized in that, It includes a battery cell according to any one of claims 1-26.

28. An electrical device, characterized in that, It includes a battery according to claim 27.

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