Battery monomer, battery device and electric device

Abstract

The utility model discloses a battery monomer, a battery device and a power utilization device, and belongs to the technical field of batteries. The battery cell includes a housing including a first wall, a first electrode terminal, an electrode assembly, a first current collecting member, a first insulator, and a second insulator. The electrode assembly is accommodated in the housing, and the electrode assembly comprises a first tab. The first electrode terminal is arranged on the first wall. The first current collecting component is arranged between the first wall and the electrode assembly, the first current collecting component comprises a first part and a second part which are connected with each other, the first part is connected with the first electrode terminal, and the second part is connected with the first tab. The first insulator is disposed between the first wall and the electrode assembly to insulate and isolate the first wall from the electrode assembly. The second insulator is disposed between the second portion and the first wall, and a melting point of the second insulator is greater than a melting point of the first insulator. The battery monomer has relatively high reliability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a battery monomer, a battery device and a power utilization device. BACKGROUND

[0002] Energy saving and emission reduction is the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their energy saving and environmental protection advantages. For electric vehicles, battery technology is an important factor for their development.

[0003] How to improve the reliability of the battery monomer is a problem to be solved in the battery technology. CONTENT OF THE INVENTION

[0004] In view of the above problems, the present application provides a battery monomer, a battery device and a power utilization device, which can improve the reliability of the battery monomer.

[0005] In a first aspect, the present application provides a battery monomer, which comprises a housing, a first electrode terminal, an electrode assembly, a first current collecting member, a first insulating piece and a second insulating piece. The housing comprises a first wall. The electrode assembly is accommodated in the housing and comprises a first tab. The first electrode terminal is arranged on the first wall. The first current collecting member is arranged between the first wall and the electrode assembly and comprises a first part and a second part connected to each other, the first part being connected to the first electrode terminal and the second part being connected to the first tab. The first insulating piece is arranged between the first wall and the electrode assembly to insulate and separate the first wall and the electrode assembly. The second insulating piece is arranged between the second part and the first wall, and the melting point of the second insulating piece is higher than that of the first insulating piece.

[0006] In the technical solution of the present application, the second insulating piece is arranged between the second part and the first wall, and the melting point of the second insulating piece is higher than that of the first insulating piece. The second insulating piece is more difficult to melt than the first insulating piece. Even if the first insulating piece is partially melted in the later stage of thermal runaway of the battery monomer, the second insulating piece can still play a role in insulating and separating the second part and the first wall, thereby reducing the risk of short circuit between the first current collecting member and the first wall causing the battery monomer to catch fire and explode, and improving the reliability of the battery monomer.

[0007] In one or more embodiments of the first aspect, the melting point of the second insulating piece is greater than 250℃.

[0008] In the scheme, when the melting point of the second insulating piece is greater than 250 DEG C, the second insulating piece has a high melting point and is not easy to melt in the later stage of thermal runaway of the battery monomer. Even if the first insulating piece is partially melted in the later stage of thermal runaway of the battery monomer, the second insulating piece can still play a role in insulating and separating the second part and the first wall, thereby reducing the risk of short circuit between the second part and the first wall to cause fire and explosion of the battery monomer.

[0009] In one or more embodiments of the first aspect, the material of the second insulating piece includes perfluoroalkyl ethyl or polyimide.

[0010] In the scheme, perfluoroalkyl ethyl or polyimide has a high melting point and high toughness. Even if the second insulating piece is partially melted, the risk of the second insulating piece piercing the separator to cause short circuit between the positive and negative electrode plates of the electrode assembly is relatively low, which can further reduce the risk of fire or explosion of the battery monomer.

[0011] In one or more embodiments of the first aspect, the second insulating piece is at least partially embedded in the first insulating piece.

[0012] In the scheme, since the second insulating piece is at least partially embedded in the first insulating piece, the second insulating piece can share part of the space with the first insulating piece.

[0013] In one or more embodiments of the first aspect, the first insulating piece is provided with a through hole penetrating in the thickness direction of the first wall, and the second insulating piece is arranged in the through hole.

[0014] In the scheme, since the second insulating piece is arranged in the through hole, on the one hand, the second insulating piece can share part of the space with the first insulating piece, which is conducive to improving the energy density of the battery monomer. On the other hand, the through hole can be used as a positioning reference for the second insulating piece, which is convenient for assembling the second insulating piece.

[0015] In one or more embodiments of the first aspect, the first insulating piece includes a base body and a boss, the boss protrudes from the base body towards the electrode assembly, and the boss abuts against the electrode assembly. The through hole is arranged in the base body.

[0016] In the scheme, the boss abutting against the electrode assembly can reduce the risk of electrode assembly shaking, which is conducive to improving the structural stability of the battery monomer. At the same time, when the second insulating piece is assembled into the through hole, due to the arrangement of the boss, there is a certain space between the surface of the base body away from the base body and the boss. Therefore, the operation space for positioning and connecting the second insulating piece and the through hole is larger, and the assembly is more convenient.

[0017] In one or more embodiments of the first aspect, in the thickness direction of the first wall, the thickness of the second insulating piece is less than or equal to the thickness of the base body.

[0018] In the above scheme, along the thickness direction of the first wall, the thickness of the second insulating member is less than or equal to the thickness of the base body, which is conducive to reducing the volume and weight of the second insulating member under the premise of meeting the basic insulation performance of the second insulating member, thereby improving the energy density of the battery monomer. At the same time, during normal use of the battery monomer, since the thickness of the second insulating member is relatively thin, compared with the first insulating member without the second insulating member, the second insulating member does not increase the difficulty of heat dissipation, that is, the heat conduction distance of heat in the second insulating member is relatively short, and the battery monomer can maintain good heat dissipation performance, thereby reducing the risk of heat accumulation accelerating the melting of the second insulating member to cause the short circuit between the second part and the first wall.

[0019] In one or more embodiments of the first aspect, the base body has a first surface facing the electrode assembly and a second surface away from the electrode assembly. The second insulating member does not protrude from the first surface, and / or the second insulating member does not protrude from the second surface.

[0020] In the above scheme, since the second insulating member does not protrude from the first surface, the second insulating member shares part of the space with the first insulating member while the arrangement of the second insulating member does not interfere with the assembly of the second part and the electrode terminal. Since the second insulating member does not protrude from the second surface, the second insulating member shares part of the space with the first insulating member while the arrangement of the second insulating member does not interfere with the assembly of the first insulating member and the first wall.

[0021] In one or more embodiments of the first aspect, along the thickness direction of the first wall, the thickness of the second insulating member is H1, which satisfies 0.2mm≤H1≤2mm.

[0022] In the above scheme, when H1≥0.2mm, the second insulating member has a larger thickness and a higher melting difficulty, which has a better effect of insulating and isolating the second part and the first wall in the later period of thermal runaway of the battery monomer, thereby being conducive to making the battery monomer have higher reliability. When H1≤2mm, the second insulating member has a smaller volume and occupies less space, which is conducive to making the battery monomer have higher energy density. Therefore, when 0.2mm≤H1≤2mm, the battery monomer can have both higher reliability and higher energy density.

[0023] In one or more embodiments of the first aspect, in the same projection plane perpendicular to the thickness direction of the first wall, the orthographic projection of the second part is located in the orthographic projection of the second insulating member.

[0024] In the above scheme, the orthographic projection of the second portion is located in the orthographic projection of the second insulating member in the same projection plane perpendicular to the thickness direction of the first wall. Even if the first insulating member is partially melted in the later stage of thermal runaway of the battery monomer, since the second insulating member completely covers the second portion, the risk of short circuit between the second portion and the first wall causing the battery monomer to catch fire and explode can be significantly reduced, and the reliability of the battery monomer is improved.

[0025] In one or more embodiments of the first aspect, the minimum distance between the edge of the orthographic projection of the second insulating member and the edge of the orthographic projection of the second portion is D1, which satisfies: 1mm≤D1≤10mm.

[0026] In the above scheme, when D1≥1mm, the edge of the orthographic projection of the second insulating member and the edge of the orthographic projection of the second portion have a larger distance, the second portion has a lower risk of short circuit with the first wall, and the reliability of the battery monomer is higher. When D1≤10mm, the amount of the second insulating member is smaller, which is conducive to reducing the cost of the battery monomer under the premise of meeting the insulation performance. Therefore, when 1mm≤D1≤10mm, the battery monomer can have both high reliability and low cost.

[0027] In one or more embodiments of the first aspect, the second insulating member is thermally fused to the first insulating member.

[0028] In the above scheme, the second insulating member and the first insulating member are connected together by thermal fusion, which has relatively high connection strength and is suitable for automatic production, thereby improving the assembly efficiency of the battery monomer.

[0029] In one or more embodiments of the first aspect, the second insulating member is connected to the first wall.

[0030] In the above scheme, the first wall can serve as an assembly base of the second insulating member, thereby reducing the assembly difficulty of the second insulating member. Meanwhile, in the embodiment in which the material strength of the first wall is relatively high, connecting the second insulating member to the first wall can to some extent disperse the assembly stress of the second insulating member, thereby improving the structural stability of the second insulating member after assembly.

[0031] In one or more embodiments of the first aspect, the battery monomer further comprises a pressure relief mechanism, and the pressure relief mechanism is arranged on the first wall.

[0032] In the above scheme, when the battery monomer is in thermal runaway, part of the gas in the exhaust is discharged by the pressure relief mechanism arranged on the first wall. In the later stage of thermal runaway of the battery monomer, the internal pressure of the battery monomer is greater than the external pressure, and the electrode assembly has a tendency to move close to the first wall. At this time, the risk of abutment between the electrode assembly and the first wall is relatively high. The arrangement of the second insulating member can significantly reduce the risk of short circuit between the second portion and the first wall causing the battery monomer to catch fire and explode.

[0033] In one or more embodiments of the first aspect, the second portion and the first tab form a first connecting part, and a projection of the second insulating member on a same projection plane perpendicular to a thickness direction of the first wall at least partially overlaps the first connecting part.

[0034] In the above scheme, the position of the first connecting part formed by the second portion and the first tab is generally weak in structural strength, and when the first current collecting member is subjected to a force, the position of the first connecting part is more likely to deform relatively greatly, and the risk of the position of the first connecting part being short-circuited with the first wall is higher. By setting the projection of the second insulating member on the same projection plane perpendicular to the thickness direction of the first wall to at least partially overlap the first connecting part, the risk of the first current collecting member being short-circuited with the first wall to cause the battery cell to catch fire or explode can be significantly reduced.

[0035] In one or more embodiments of the first aspect, a plurality of electrode assemblies are provided, the second portion and the first tab of the plurality of electrode assemblies form a plurality of first connecting parts, and a plurality of second insulating members are provided, the plurality of second insulating members correspond one-to-one to the plurality of first connecting parts.

[0036] In the above scheme, since the second insulating member is provided at the position of each first connecting part, the risk of each first connecting part being short-circuited with the first wall is reduced, thereby improving the reliability of the battery cell.

[0037] In one or more embodiments of the first aspect, the electrode assembly includes a second tab. The battery cell further includes a second electrode terminal, a second current collecting member, and a third insulating member. The second electrode terminal is arranged on the first wall. The second current collecting member is arranged between the first wall and the electrode assembly, and includes a third portion and a fourth portion connected to each other, the third portion is connected to the second electrode terminal, and the fourth portion is connected to the second tab. The third insulating member is arranged between the fourth portion and the first wall, and the melting point of the third insulating member is greater than the melting point of the first insulating member.

[0038] In the above scheme, since the third insulating member is arranged between the fourth portion and the first wall, and the melting point of the third insulating member is greater than the melting point of the first insulating member, the third insulating member is more difficult to melt than the first insulating member. Even if the first insulating member is partially melted in the later stage of thermal runaway of the battery cell, the third insulating member can still play a role in insulating and separating the fourth portion and the first wall, thereby reducing the risk of the second current collecting member being short-circuited with the first wall to cause the battery cell to catch fire and explode, and improving the reliability of the battery cell.

[0039] In a second aspect, the present application provides a battery device including the battery cell in one or more embodiments described above.

[0040] In the above scheme, since the battery monomer in one or more embodiments has high reliability, the battery device including the battery monomer in one or more embodiments also has high reliability.

[0041] In a third aspect, the application provides a power consumption device including the battery monomer or the battery device in one or more embodiments. Since the battery monomer or the battery device in one or more embodiments has high reliability, the power consumption device including the battery monomer or the battery device in one or more embodiments also has high reliability.

[0042] The above description is only a summary of the technical solutions of the application. In order to enable the technical means of the application to be more clearly understood, the following detailed description of the specific embodiments of the application can be implemented according to the content of the description, and in order to enable other purposes, features and advantages of the application to be more obvious and easy to understand, the following detailed description of the specific embodiments of the application. BRIEF DESCRIPTION OF DRAWINGS

[0043] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are intended to only illustrate preferred embodiments and are not intended to be limiting of the application. Moreover, like reference numerals designate similar parts throughout the several views. In the drawings:

[0044] Figure 1 Structure diagram of a vehicle for some embodiments of the application;

[0045] Figure 2 Exploded view of a battery device for some embodiments of the application;

[0046] Figure 3 Exploded view of a battery monomer for some embodiments of the application;

[0047] Figure 4 Exploded view of a partial structure of a battery monomer for some embodiments of the application;

[0048] Figure 5 Structure diagram of a partial structure of a battery monomer for some embodiments of the application;

[0049] Figure 6 Sectional view of a partial structure of a battery monomer for some embodiments of the application;

[0050] Figure 7 For Figure 6 Local enlarged view at A in FIG. 8.

[0051] 1000 - vehicle; 200 - controller; 300 - motor; 100 - battery device; 11 - case; 111 - first case; 112 - second case; 12 - battery cell; 121 - housing; 1210 - first wall; 1211 - end cap; 1212 - shell; 122 - electrode assembly; 1220 - first current collector member; 1221 - first portion; 1222 - second portion; 1223 - main body; 1224 - first tab; 1225 - second tab; 123 - first insulating member; 1231 - through hole; 1232 - base; 12321 - first surface; 12322 - second surface; 1233 - boss; 1234 - protrusion; 1235 - via hole; 1236 - drainage hole; 124 - second current collector member; 1241 - third portion; 1242 - fourth portion; 125 - first electrode terminal; 126 - pressure relief mechanism; 127 - second insulating member; 128 - third insulating member; 129 - second electrode terminal. DETAILED DESCRIPTION

[0052] The embodiments of the technical solutions of the present application will be described in detail below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application; the terms "include" and "have" and any variations thereof used in the specification and the claims and the above description of drawings are intended to cover the inclusion not the exclusion of one or more elements.

[0054] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

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

[0056] In the description of the embodiments of the present application, the term "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).

[0057] In the embodiments of the present application, the battery cell can be a secondary battery, which refers to a battery cell that can be activated by charging after discharging.

[0058] The battery cell includes, but is not limited to, a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel-hydrogen battery, a nickel-cadmium battery, a lead-acid battery, etc.

[0059] The battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of the battery cell, active ions (such as lithium ions) are inserted and extracted between the positive electrode and the negative electrode. The separator is arranged between the positive electrode and the negative electrode, which can reduce the risk of short circuit between the positive electrode and the negative electrode, and at the same time allow the active ions to pass through.

[0060] In some embodiments, the separator is a separator film. The separator film can be selected from any known porous structure separator film with good chemical stability and mechanical stability.

[0061] As an example, the material of the separator film can include at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator film can be a single-layer film or a multi-layer composite film. When the separator film is a multi-layer composite film, the materials of the layers can be the same or different. The separator can be a separate component located between the positive and negative electrodes, or can be attached to the surface of the positive and negative electrodes.

[0062] In some embodiments, the separator is a solid-state electrolyte. The solid-state electrolyte is arranged between the positive electrode and the negative electrode, and at the same time plays the role of transmitting ions and isolating the positive and negative electrodes.

[0063] In some embodiments, the battery cell further includes an electrolyte, which plays the role of conducting ions between the positive and negative electrodes. The electrolyte can be in a liquid state, a gel state, or a solid state.

[0064] In some embodiments, the electrode assembly is a wound structure. The positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0065] In some embodiments, the electrode assembly is a stacked structure.

[0066] As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets can be arranged alternately and stacked.

[0067] As an example, the positive electrode tab can be provided in plurality, and the negative electrode tab can be folded to form a plurality of folded segments stacked in layers.

[0068] As an example, the positive electrode tab and the negative electrode tab can be folded to form a plurality of folded segments stacked in layers.

[0069] As an example, the separator can be provided in plurality, and can be provided between any adjacent positive electrode tab or negative electrode tab.

[0070] As an example, the separator can be provided in plurality, and can be provided between any adjacent positive electrode tab or negative electrode tab.

[0071] In some embodiments, the electrode assembly can have a cylindrical shape, a flat shape, or a polygonal shape.

[0072] In some embodiments, the electrode assembly can be provided with a tab, and the tab can guide current out of the electrode assembly. The tab can include a positive electrode tab and a negative electrode tab.

[0073] In some embodiments, the battery cell can include a case. The case can be used to enclose the electrode assembly and other components such as an electrolyte. The case can be a steel case, an aluminum case, a plastic case (e.g., polypropylene), a composite metal case (e.g., a copper-aluminum composite case), or an aluminum-plastic film.

[0074] In some embodiments, the battery cell can further include a pressure relief mechanism provided on the case. The pressure relief mechanism can be used to release pressure inside the battery cell when the internal pressure or temperature of the battery cell reaches a predetermined value.

[0075] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell having another shape. The prismatic battery cell can include a square battery cell, a blade battery cell, a polygonal battery cell (e.g., a hexagonal battery cell), etc.

[0076] A battery apparatus according to embodiments of the present application can include one or more battery cell assemblies to provide voltage and capacity. The battery cell assembly can include a plurality of battery cells connected in series, in parallel, or in a mixed connection through a busbar.

[0077] In some embodiments, a battery cell assembly is typically formed by arranging a plurality of battery cells. As an example, the battery cell assembly can be a battery module, which is formed by arranging and fixing a plurality of battery cells into a separate module. As an example, the battery module can be formed by bundling a plurality of battery cells by a cable tie.

[0078] In some embodiments, the battery device can be a battery pack, which includes a case and one or more battery cell assemblies housed in the case.

[0079] As an example, the battery cell assembly can be a battery module, which can be housed in the case by fixing the battery module in the case.

[0080] As an example, the battery cell assembly can also be housed in the case by directly fixing a plurality of battery cells in the case.

[0081] In some embodiments, the case can be part of the chassis structure of a vehicle. For example, part of the case can be at least part of the floor of the vehicle, or part of the case can be at least part of the cross beam and the longitudinal beam of the vehicle.

[0082] In some embodiments, the battery can be an energy storage device. The energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0083] In the following, the embodiments will mainly be described with respect to a cuboid battery cell. It should be understood that the embodiments described in the following are also applicable to cylindrical battery cells or pouch battery cells or blade battery cells in some aspects.

[0084] In a typical battery cell structure, the battery cell includes a housing, an electrode assembly, and an electrolyte. The housing includes an end cap and a case, and the end cap closes the opening of the case to define a receiving space for receiving the electrode assembly.

[0085] The development of battery technology needs to consider various design factors, such as performance parameters such as energy density, cycle life, discharge capacity, and charge-discharge rate, in addition to the reliability of the battery device.

[0086] Generally, a battery cell includes a housing, an electrode assembly, and an electrode terminal disposed on the housing, and the electric energy inside the battery cell is led out through a second part of the electrode assembly electrically connected with the electrode terminal. In order to reduce the risk of internal short circuit of the battery cell, an insulating structure such as a lower plastic is generally arranged between the second part and the housing. However, when the battery cell is in a state of a later period of thermal runaway, the temperature inside the battery cell is relatively high, and the risk of melting of the lower plastic is relatively high. When the lower plastic is partially melted, the risk of short circuit between the second part and the housing is significantly increased. At this time, once the second part is short-circuited with the housing, the battery cell may catch fire or explode, and the reliability of the battery cell is relatively low.

[0087] In view of this, the present application provides a battery cell, which includes a housing, a first electrode terminal, an electrode assembly, a first current collecting member, a first insulating member, and a second insulating member. The housing includes a first wall. The electrode assembly is accommodated in the housing and includes a first tab. The first electrode terminal is disposed on the first wall. The first current collecting member is disposed between the first wall and the electrode assembly and includes a first part and a second part connected with each other, the first part is connected with the first electrode terminal, and the second part is connected with the first tab. The first insulating member is disposed between the first wall and the electrode assembly to insulate and separate the first wall and the electrode assembly. The second insulating member is disposed between the second part and the first wall, and the melting point of the second insulating member is greater than the melting point of the first insulating member. Since the second insulating member is disposed between the second part and the first wall, and the melting point of the second insulating member is greater than the melting point of the first insulating member, the second insulating member is more difficult to melt than the first insulating member. Even if the first insulating member is partially melted in the later period of thermal runaway of the battery cell, the second insulating member can still play a role in insulating and separating the second part and the first wall, thereby reducing the risk of short circuit between the first current collecting member and the first wall, and causing the battery cell to catch fire and explode, and being conducive to improving the reliability of the battery cell.

[0088] The technical solutions described in the embodiments of the present application are applicable to battery cells, battery devices, and electric devices using the battery devices.

[0089] The electric device includes but is not limited to a battery car, an electric vehicle, a ship, and a spacecraft, etc. For example, the spacecraft includes an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0090] The following embodiments are described for convenience of illustration by taking a vehicle as an example of an electric device according to an embodiment of the present application.

[0091] Please refer to FIG. Figure 1A structural schematic diagram of a vehicle 1000 is provided for some embodiments of the present application. The vehicle 1000 is internally provided with a battery device 100, which can be arranged at the bottom or head or tail of the vehicle 1000. The battery device 100 can be used for power supply of the vehicle 1000, for example, the battery device 100 can be used as the operating power supply of the vehicle 1000.

[0092] The vehicle 1000 can further include a controller 200 and a motor 300, the controller 200 being used to control the battery device 100 to supply power to the motor 300, for example, for the working power demand of the vehicle 1000 during starting, navigation and driving.

[0093] In some embodiments of the present application, the battery device 100 can not only be used as the operating power supply of the vehicle 1000, but also be used as the driving power supply of the vehicle 1000, replacing or partially replacing the fuel or natural gas to provide driving power for the vehicle 1000.

[0094] Please refer to Figure 2 , Figure 2 An exploded view of the battery device 100 is provided for some embodiments of the present application. The battery device 100 can include a battery monomer 12 and a box 11, the battery monomer 12 being contained in the box 11.

[0095] The box 11 is a component containing the battery monomer 12, and the box 11 provides a containing space for the battery monomer 12, and the box 11 can adopt various structures. In some embodiments, the box 11 can include a first box 111 and a second box 112, the first box 111 and the second box 112 being mutually covered to define a containing space for containing the battery monomer 12. The first box 111 and the second box 112 can have various shapes, such as cuboid, cylinder, etc. The first box 111 can be a hollow structure with one side open, and the second box 112 can also be a hollow structure with one side open, and the open side of the second box 112 is covered on the open side of the first box 111, thereby forming the box 11 with the containing space. The first box 111 can be a hollow structure with one side open, and the second box 112 can be a plate structure, and the second box 112 is covered on the open side of the first box 111, thereby forming the box 11 with the containing space. The first box 111 and the second box 112 can be sealed by a sealing element, which can be a sealing ring, sealing glue, etc.

[0096] In the battery device 100, the battery cell 12 can be one or multiple. If the battery cell 12 is multiple, the multiple battery cells 12 can be connected in series, in parallel, or in a mixed connection, where the mixed connection means that the multiple battery cells 12 are connected in series and in parallel. The multiple battery cells 12 can be connected in series, in parallel, or in a mixed connection to form a battery module, and the multiple battery modules can be connected in series, in parallel, or in a mixed connection to form a whole, which is accommodated in the case 11. Alternatively, all the battery cells 12 can be directly connected in series, in parallel, or in a mixed connection, and the whole formed by the battery cells 12 is accommodated in the case 11.

[0097] Please refer to Figure 3 , Figure 3 An exploded view of the battery cell 12 is provided for some embodiments of the present application. The battery cell 12 can include a shell 121 and an electrode assembly 122, and the electrode assembly 122 is accommodated in the shell 121.

[0098] In some embodiments, the shell 121 can include a housing 1212 and an end cover 1211, the housing 1212 has an opening, and the end cover 1211 closes the opening of the housing 1212.

[0099] The housing 1212 is a component for accommodating the electrode assembly 122, and the housing 1212 can be a hollow structure with an opening at one end or at opposite ends. The housing 1212 can have various shapes, such as a cylindrical shape, a cuboid shape, etc. The material of the housing 1212 can be various, such as copper, iron, aluminum, steel, aluminum alloy, etc. The electrode assembly 122 can be partially located in the housing 1212 or entirely located in the housing 1212.

[0100] The end cover 1211 is a component for closing the opening of the housing 1212 to isolate the internal environment of the battery cell 12 from the external environment. The end cover 1211 cooperates with the housing 1212 to define a receiving space for accommodating the electrode assembly 122, electrolyte, and other components. The end cover 1211 can be connected to the housing 1212 by welding or crimping to close the opening of the housing 1212. The shape of the end cover 1211 can be adapted to the shape of the housing 1212, such as the housing 1212 being a cuboid structure and the end cover 1211 being a rectangular plate structure adapted to the housing 1212, or the housing 1212 being a cylindrical structure and the end cover 1211 being a circular plate structure adapted to the housing 1212. The material of the end cover 1211 can also be various, such as copper, iron, aluminum, steel, aluminum alloy, etc. The material of the end cover 1211 can be the same as or different from that of the housing 1212.

[0101] In the embodiment where the shell 1212 is open at one end, one end cover 1211 can be correspondingly provided. In the embodiment where the shell 1212 is open at two opposite ends, two end covers 1211 can be correspondingly provided, and the two end covers 1211 respectively seal the two openings of the shell 1212, and the two end covers 1211 and the shell 1212 together define the accommodation space.

[0102] In some embodiments, the battery cell 12 can further include an electrode terminal provided on the shell 121, and the electrode terminal is electrically connected to the tab of the electrode assembly 122 to input or output the electric energy of the battery cell 12. The electrode terminal can be provided on the shell 1212 of the shell 121 or on the end cover 1211 of the shell 121. The electrode terminal can be directly connected to the tab, for example, the electrode terminal is welded to the tab. The electrode terminal can also be indirectly connected to the tab, for example, the electrode terminal is indirectly connected to the tab through a current collecting member. The current collecting member can be a metal conductor, for example, copper, iron, aluminum, steel, aluminum alloy, etc. Exemplarily, the material of the electrode terminal can be various, for example, the material of the electrode terminal can be copper, iron, aluminum, steel, aluminum alloy, etc. Of course, in some embodiments, the electrode terminal can also be a composite material, that is, the electrode terminal is connected by two different materials of metal, for example, hot pressing or cold pressing, etc.

[0103] In some embodiments, the battery cell 12 can further include a pressure relief mechanism 126, and the pressure relief mechanism 126 can be provided on the end cover 1211 or the shell 1212. The pressure relief mechanism 126 can be a pressure relief component mounted on the shell 1212 or the end cover 1211, for example, a rupture disc, a safety valve, etc. The pressure relief mechanism 126 can also be integrally formed with the end cover 1211 or the shell 1212. The pressure relief mechanism 126 can be provided with a pressure relief groove to be cracked along the pressure relief groove when the battery cell 12 is relieved. The pressure relief groove can be a groove extending along a closed trajectory, and the closed trajectory can be a circular trajectory, a rectangular trajectory, etc. The pressure relief groove can also be a groove extending along a non-closed trajectory, and the non-closed trajectory can be an H-shaped trajectory, a Y-shaped trajectory, a V-shaped trajectory, a U-shaped trajectory, etc.

[0104] According to some embodiments of the present application, please refer to Figures 3-5The battery cell 12 includes a housing 121, a first electrode terminal 125, an electrode assembly 122, a first current collecting member 1220, a first insulating member 123, and a second insulating member 127. The housing 121 includes a first wall 1210. The electrode assembly 122 is accommodated in the housing 121, and includes a first tab 1224. The first electrode terminal 125 is disposed on the first wall 1210. The first current collecting member 1220 is disposed between the first wall 1210 and the electrode assembly 122, and includes a first portion 1221 and a second portion 1222 connected to each other, the first portion 1221 being connected to the first electrode terminal 125, and the second portion 1222 being connected to the first tab 1224. The first insulating member 123 is disposed between the first wall 1210 and the electrode assembly 122 to insulate and separate the first wall 1210 and the electrode assembly 122. The second insulating member 127 is disposed between the second portion 1222 and the first wall 1210, and has a melting point greater than that of the first insulating member 123.

[0105] The first portion 1221 is connected to the first electrode terminal 125, and the second portion 1222 is connected to the first tab 1224. Since the first electrode terminal 125 has higher structural stability than the first tab 1224, the first portion 1221 connected to the first electrode terminal 125 is more difficult to deform, in other words, when the first current collecting member 1220 is subjected to a force, the second portion 1222 is more likely to deform greatly, that is, the second portion 1222 is more likely to contact the first wall 1210 and be short-circuited.

[0106] In some embodiments, the housing 121 can be a sealed structure or a non-sealed structure. As an example, when the housing 121 is a sealed structure, the housing 121 can protect the electrode assembly 122 and prevent, to some extent, leakage of electrolyte and the like. When the housing 121 is a non-sealed structure, the housing 121 can protect the electrode assembly 122, and a sealing bag can be further included between the housing 121 and the electrode assembly 122, the sealing bag being used to package the electrode assembly 122, electrolyte, and the like. Specifically, the sealing bag can be a bag-shaped insulating member or an aluminum plastic film.

[0107] The first wall 1210 can be located on any wall of the housing 121.

[0108] In some embodiments, the first insulating member 123 is provided with a via hole 1235 corresponding in position to the first electrode terminal 125, and at least part of the first electrode terminal 125 passes through the via hole 1235 to be connected to the second portion 1222.

[0109] In some embodiments, the first wall 1210 can be located on the wall with the largest outer surface area in the housing 1212.

[0110] In some embodiments, the first wall 1210 is an end cap 1211. The end cap 1211 closes the opening of the housing 1212. For example, Figure 6 and Figure 7 In some embodiments, the end cap 1211 has an inner surface facing the electrode assembly 122, an outer surface facing away from the electrode assembly 122, and an outer peripheral surface connecting the inner surface and the outer surface along the thickness direction of the end cap 1211. The outer peripheral surface is connected with the inner peripheral surface of the housing 1212 to close the opening of the housing 1212. In other embodiments, the housing 1212 has an end surface connecting the outer peripheral surface and the inner peripheral surface, and the inner surface of the end cap 1211 is connected with the end surface to close the opening of the housing 1212.

[0111] The electrode assembly 122 is located in the receiving space defined by the housing 1212 and the end cap 1211. The electrode assembly 122 can be a laminated structure or a wound structure. The electrode assembly 122 in the housing 1212 can be one or multiple. If the electrode assembly 122 is multiple, the multiple electrode assemblies 122 can be stacked. For example, the multiple electrode assemblies 122 can be stacked along the stacking direction of the flat area of one of the electrode assemblies 122. The flat area is the flat part of the electrode assembly 122. If the electrode assembly 122 is a laminated structure, the electrode assembly 122 is a laminated electrode assembly 122. The electrode assembly 122 can be the whole flat area. If the electrode assembly 122 is a wound structure, the electrode assembly 122 also has a corner area. The flat area is provided with the corner area at least at one end along the direction intersecting with the flat area.

[0112] The first current collecting member 1220 is used to lead out the electric energy of the electrode assembly 122. The electrode assembly 122 includes a main body 1223 and a first tab 1224, and the first tab 1224 is arranged at one end of the main body 1223. The main body 1223 is a main part of the electrode assembly 122 to generate an electrochemical reaction in the battery cell 12, and the first tab 1224 is connected to the main body 1223 at one end of the main body 1223 facing the wall portion in the thickness direction of the first wall 1210, i.e., the first tab 1224 is located between the main body 1223 and the first wall 1210 in the thickness direction of the first wall 1210, so that the first tab 1224 is connected to the first electrode terminal 125 through the first current collecting member 1220. It should be noted that the first tab 1224 of the electrode assembly 122 can be a part formed by stacking regions on which the positive active material layer is not coated on the positive electrode plate or a part formed by stacking regions on which the negative active material layer is not coated on the negative electrode plate. If the first tab 1224 is used to output the positive electrode of the electrode assembly 122, the first tab 1224 is a part formed by stacking regions on which the positive active material layer is not coated on the positive electrode plate. If the first tab 1224 is used to output the negative electrode of the electrode assembly 122, the first tab 1224 is a part formed by stacking regions on which the negative active material layer is not coated on the negative electrode plate. Of course, in some embodiments, the electrode assembly 122 can also include a second tab 1225, and the polarity of the second tab 1225 is opposite to that of the first tab 1224.

[0113] The first current collecting member 1220 can also be referred to as an adapter, the first tab 1224 is connected to the first current collecting member 1220, and the first current collecting member 1220 is connected to the first electrode terminal 125, so as to lead out the electric energy of the electrode assembly 122 by the current collecting member. The first part 1221 is the part of the first current collecting member 1220 connected to the first electrode terminal 125. For example, the first current collecting member 1220 and the first electrode terminal 125 are connected by welding, and the first part 1221 is the region of the first current collecting member 1220 on which the first electrode terminal 125 is welded to form a welding mark.

[0114] The second insulating member 127 is arranged between the second part 1222 and the first wall 1210, which means that the second insulating member 127 can be connected to the second part 1222, or can be connected to the first wall 1210, or can be connected to both the second part 1222 and the first wall 1210. Of course, the second insulating member 127 can also not be connected to both the second part 1222 and the first wall 1210, but be located between the two.

[0115] The material of the first insulating member 123 can include but is not limited to polypropylene and the like.

[0116] The material of the second insulating member 127 can include but is not limited to perfluoroalkyl ethyl, polyimide and the like.

[0117] The melting point of the material of the second insulating member 127 is greater than the melting point of the material of the first insulating member 123, that is, the second insulating member 127 is more resistant to high temperature and more difficult to melt than the first insulating member 123. When the internal temperature of the battery monomer 12 is too high, the first insulating member 123 will be softened or melted first compared with the second insulating member 127.

[0118] It should be noted that the melting point of the material of the second insulating member 127 is the temperature at which the second insulating member 127 changes from a hard solid state to a liquid state or is softened and melted from a hard solid state to a molten viscous state. Similarly, the melting point of the material of the first insulating member 123 is the temperature at which the insulating member changes from a hard solid state to a liquid state or is softened and melted from a hard solid state to a molten viscous state.

[0119] In the technical scheme of the embodiment of the application, the second insulating member 127 is arranged between the second part 1222 and the first wall 1210, and the melting point of the second insulating member 127 is greater than the melting point of the first insulating member 123. The second insulating member 127 is more difficult to melt than the first insulating member 123. Even if the first insulating member 123 is partially melted in the later stage of thermal runaway of the battery monomer 12, the second insulating member 127 can still play a role in insulating and isolating the second part 1222 and the first wall 1210, thereby reducing the risk of short circuiting of the current collecting member and the first wall 1210 causing the battery monomer 12 to catch fire and explode, and improving the reliability of the battery monomer 12.

[0120] According to some embodiments of the application, the melting point of the second insulating member 127 is greater than 250°C.

[0121] The melting point of the second insulating member 127 can be any value greater than 250°C, for example, any one of 255°C, 260°C, 265°C, 270°C, 275°C, 280°C, 285°C, 290°C, 295°C, 300°C, 305°C, 310°C, 315°C, 320°C, 330°C, 340°C, 350°C, 360°C, 370°C, 380°C, 390°C, 400°C, or a range value between any two of them.

[0122] In the above scheme, when the melting point of the second insulating member 127 is greater than 250°C, the second insulating member 127 has a high melting point and is not easily melted in the later stage of thermal runaway of the battery monomer 12. Even if the first insulating member 123 is partially melted in the later stage of thermal runaway of the battery monomer 12, the second insulating member 127 can still play a role in insulating and isolating the second part 1222 and the first wall 1210, thereby reducing the risk of short circuiting of the second part 1222 and the first wall 1210 causing the battery monomer 12 to catch fire and explode.

[0123] According to some embodiments of the present application, the material of the second insulation piece 127 includes perfluoroalkyl ethyl or polyimide.

[0124] The above scheme uses perfluoroalkyl ethyl or polyimide, which has a relatively high melting point and high toughness. Even if the second insulation piece 127 melts, the risk of the second insulation piece 127 falling and piercing the isolation piece to cause the positive and negative electrode plates of the electrode assembly 122 to be short-circuited is relatively low, which can further reduce the risk of fire or explosion of the battery monomer 12.

[0125] According to some embodiments of the present application, please refer to Figures 3-5 The second insulation piece 127 is at least partially embedded in the first insulation piece 123.

[0126] The second insulation piece 127 is at least partially embedded in the first insulation piece 123, which means that the second insulation piece 127 shares part of the space with the first insulation piece 123.

[0127] In some embodiments, the surface of the second insulation piece 127 along the thickness direction of the first wall 1210 is provided with a groove, and at least part of the second insulation piece 127 is arranged in the groove. The opposite two surfaces of the second insulation piece 127 along the thickness direction of the first wall 1210 can be provided with grooves, the positions of the above two grooves correspond, the number of the second insulation piece 127 can be at least two, and the second insulation piece 127 is accommodated in the two grooves.

[0128] In the above scheme, since the second insulation piece 127 is at least partially embedded in the first insulation piece 123, the second insulation piece 127 can share part of the space with the first insulation piece 123.

[0129] According to some embodiments of the present application, please refer to Figures 3-5 The first insulation piece 123 is provided with a through hole 1231 penetrating along the thickness direction of the first wall 1210, and the second insulation piece 127 is arranged in the through hole 1231.

[0130] The through hole 1231 can be formed by machining or other methods after the first insulation piece 123 is formed, of course, the through hole 1231 can also be formed integrally with the first insulation piece 123 by injection molding or other methods.

[0131] The second insulation piece 127 is arranged in the through hole 1231, which means that at least part of the second insulation piece 127 is located in the through hole 1231. It can also be understood that the second insulation piece 127 is arranged in the through hole 1231, one part of the second insulation piece 127 is located outside the through hole 1231, and the other part is located inside the through hole 1231.

[0132] The shape of the through hole 1231 can be circular, semicircular, polygonal, annular, etc.

[0133] In the above solution, the second insulation member 127 is arranged in the through hole 1231. On one hand, the second insulation member 127 can share part of the space with the first insulation member 123, which is beneficial to improve the energy density of the battery monomer 12. On the other hand, the through hole 1231 can be used as a positioning reference for the second insulation member 127, which facilitates the assembly of the second insulation member 127.

[0134] According to some embodiments of the present application, please refer to Figures 3-5 The first insulation member 123 includes a base body 1232 and a boss 1233, the boss 1233 protrudes from the base body 1232 towards the electrode assembly 122, and the boss 1233 abuts against the electrode assembly 122. The through hole 1231 is arranged in the base body 1232.

[0135] In some embodiments, the boss 1233 is provided with a plurality of bosses, two of which are located at the two ends of the first insulation member 123 along a first direction, and the first direction, the thickness direction of the first wall 1210 and the stacking direction of the flat area of the electrode assembly 122 are perpendicular to each other. By pressing the electrode assembly 122 with the boss 1233, the risk of the electrode assembly 122 shaking can be reduced. In some other embodiments, one of the bosses 1233 is located between the above-mentioned two bosses 1233 along the first direction.

[0136] In some embodiments, the boss 1233 can also be a ring structure.

[0137] In some embodiments, the second insulation member 127 is thermally fused with the first insulation member 123, and the second insulation member 127 is thermally fused with the hole wall of the through hole 1231.

[0138] In some embodiments, the second insulation member 127 is connected with the first wall 1210, and part of the second insulation member 127 extends into the through hole 1231 after the assembly of the battery monomer 12 is completed.

[0139] In the above solution, the boss 1233 abutting against the electrode assembly 122 can reduce the risk of the electrode assembly 122 shaking, which is beneficial to improve the structural stability of the battery monomer 12. At the same time, when the second insulation member 127 is assembled into the through hole 1231, due to the arrangement of the boss 1233, there is a certain space between the base body 1232 and the surface of the boss 1233 away from the base body 1232, which makes the operation space larger when the second insulation member 127 is positioned and connected with the through hole 1231, and the assembly is more convenient.

[0140] According to some embodiments of the present application, please refer to Figures 3-5 In the thickness direction of the first wall 1210, the thickness of the second insulation member 127 is less than or equal to the thickness of the base body 1232.

[0141] The thickness of the second insulating member 127 can refer to a maximum measurement value of multiple measurement values obtained by measuring the second insulating member 127 multiple times.

[0142] The thickness of the base body 1232 can refer to a maximum measurement value of multiple measurement values obtained by measuring the base body 1232 multiple times.

[0143] In the above scheme, in the thickness direction of the first wall 1210, the thickness of the second insulating member 127 is less than or equal to the thickness of the base body 1232, which is conducive to reducing the volume and weight of the second insulating member 127 under the premise of meeting the basic insulation performance of the second insulating member 127, thereby improving the energy density of the battery monomer 12. At the same time, during normal use of the battery monomer 12, because the thickness of the second insulating member 127 is relatively thin, compared with the first insulating member 123 without the second insulating member 127, the second insulating member 127 does not increase the difficulty of heat dissipation, that is, the heat conduction distance of heat in the second insulating member 127 is relatively short, and the battery monomer 12 can maintain good heat dissipation performance, thereby reducing the risk of heat accumulation accelerating the melting of the second insulating member 127 to cause the second part 1222 to be short-circuited with the first wall 1210.

[0144] According to some embodiments of the present application, please refer to Figures 3-5 The base body 1232 has a first surface 12321 facing the electrode assembly 122 and a second surface 12322 away from the electrode assembly 122. The second insulating member 127 does not protrude from the first surface 12321, and / or the second insulating member 127 does not protrude from the second surface 12322.

[0145] In some embodiments, the second insulating member 127 is flush with the first surface 12321 and the second surface 12322, which is conducive to reducing the risk of stress concentration at the junction of the second insulating member 127 and the first insulating member 123, and is conducive to making the second insulating member 127 and the first insulating member 123 have higher connection stability and reduce the risk of insulation failure caused by the second insulating member 127 falling off.

[0146] In the above scheme, because the second insulating member 127 does not protrude from the first surface 12321, the second insulating member 127 shares part of the space with the first insulating member 123, and the arrangement of the second insulating member 127 does not interfere with the assembly of the second part 1222 and the electrode terminal. Because the second insulating member 127 does not protrude from the second surface 12322, the second insulating member 127 shares part of the space with the first insulating member 123, and the arrangement of the second insulating member 127 does not interfere with the assembly of the first insulating member 123 and the first wall 1210.

[0147] According to some embodiments of the present application, please refer to Figures 3-5The thickness of the second insulation member 127 along the thickness direction of the first wall 1210 is H1, and 0.2 mm≤H1≤2 mm is satisfied.

[0148] The thickness of the second insulation member 127 along the thickness direction of the first wall 1210 can be any value greater than or equal to 0.2 mm and less than or equal to 2 mm, such as any one of 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, or a range between any two of these values.

[0149] In the above scheme, when H1≥0.2 mm, the second insulation member 127 has a large thickness and is difficult to melt. In the later stage of thermal runaway of the battery monomer 12, the second insulation member 127 has a good effect of insulating and isolating the second part 1222 and the first wall 1210, which is conducive to making the battery monomer 12 have high reliability. When H1≤2 mm, the volume of the second insulation member 127 is small, and the space occupied is small, which is conducive to making the battery monomer 12 have high energy density. Therefore, when 0.2 mm≤H1≤2 mm, the battery monomer 12 can have high reliability and high energy density.

[0150] According to some embodiments of the present application, please refer to Figures 3-7 In the same projection plane perpendicular to the thickness direction of the first wall 1210, the orthographic projection of the second part 1222 is located in the orthographic projection of the second insulation member 127.

[0151] In the same projection plane perpendicular to the thickness direction of the first wall 1210, the orthographic projection of the second part 1222 is located in the orthographic projection of the second insulation member 127, which means that when the electrode assembly 122 moves along the thickness direction of the first wall 1210 to approach the first wall 1210, the second insulation member 127 will completely cover the second part 1222. When the second insulation member 127 is not completely melted, the second part 1222 will always be partially blocked by the second insulation member 127.

[0152] In the above scheme, in the same projection plane perpendicular to the thickness direction of the first wall 1210, the orthographic projection of the second part 1222 is located in the orthographic projection of the second insulation member 127. Even in the later stage of thermal runaway of the battery monomer 12, the first insulation member 123 is partially melted, and since the second insulation member 127 completely covers the second part 1222, the risk of short circuit between the second part 1222 and the first wall 1210 causing the battery monomer 12 to catch fire and explode can be significantly reduced, which is conducive to improving the reliability of the battery monomer 12.

[0153] According to some embodiments of the present application, please refer toFigures 3-5 The minimum distance between the edge of the orthographic projection of the second insulating member 127 and the edge of the orthographic projection of the second portion 1222 is D1, which satisfies: 1 mm≤D1≤10 mm.

[0154] The minimum distance between the edge of the orthographic projection of the second insulating member 127 and the edge of the orthographic projection of the second portion 1222 can be any value greater than or equal to 1 mm and less than or equal to 10 mm, for example, any one of 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, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm, or a range value between any two thereof.

[0155] In the above scheme, when D1≥1 mm, the edge of the orthographic projection of the second insulating member 127 and the edge of the orthographic projection of the second portion 1222 have a larger distance, the second portion 1222 has a lower risk of short circuit with the first wall 1210, and the reliability of the battery monomer 12 is higher. When D1≤10 mm, the amount of the second insulating member 127 is smaller, which is conducive to reducing the cost of the battery monomer 12 under the premise of meeting the insulation performance. Therefore, when 1 mm≤D1≤10 mm, the battery monomer 12 can have both high reliability and low cost.

[0156] According to some embodiments of the present application, please refer to Figures 3-5 The second insulating member 127 is thermally fused to the first insulating member 123.

[0157] In some embodiments, the base 1232 has a first surface 12321 facing the electrode assembly 122 and a second surface 12322 facing away from the electrode assembly 122, and the second surface 12322 is thermally fused to the first wall 1210 to connect the base 1232 and the first wall 1210. After the base 1232 is thermally fused to the first wall 1210, a fusion portion is formed. For example, in order to form a stable connection strength between the base 1232 and the first wall 1210 after thermal fusion, a plurality of protrusions 1234 are generally arranged on the second surface 12322 to reduce the risk that the deformation of the material after thermal fusion causes the connection between the base 1232 and the first wall 1210 to be unstable. At this time, since the second insulating member 127 is arranged in the through hole 1231. Such an arrangement only needs to complete the cooperation between the second insulating member 127 and the first insulating member 123 from the first surface 12321, such as the above-mentioned gap cooperation between the two. There is no need to process an avoiding hole on the second insulating member 127 in order to avoid the protrusions 1234. The assembly difficulty is relatively low, and the assembly efficiency is relatively high, that is, there is no need to consider the problem that the second insulating member 127 cannot be cooperated due to the tolerance between the avoiding hole and the protrusions 1234. In other embodiments, the protrusions 1234 are arranged in a plurality of ways, and the plurality of protrusions 1234 are arranged along the circumference of the through hole 1231, that is, the fusion portion is arranged in a plurality of ways, and the plurality of fusion portions are distributed along the circumference of the through hole 1231. The above-mentioned arrangement can not only reduce the assembly difficulty, but also can make the first wall 1210 and the first insulating member 123 have a higher connection strength.

[0158] The above-mentioned scheme connects the second insulating member 127 and the first insulating member 123 together by thermal fusion, has a relatively high connection strength, is suitable for automatic production, and is beneficial to improve the assembly efficiency of the battery monomer 12.

[0159] According to some embodiments of the present application, please refer to Figures 3-5 , the second insulating member 127 is connected with the first wall 1210.

[0160] In some embodiments, the second insulating member 127 is thermally fused to the first wall 1210.

[0161] In some embodiments, the second insulating member 127 is adhesively connected to the first wall 1210.

[0162] In some embodiments, the first wall 1210 is an end cover 1211, the second insulating member 127 is arranged in the through hole 1231, and the second insulating member 127 can be pre-connected with the end cover 1211. When the end cover 1211 closes the opening of the shell 1212, the second insulating member 127 extends into the through hole 1231 to realize the cooperation between the second insulating member 127 and the first insulating member 123.

[0163] In the above scheme, the first wall 1210 can serve as the assembly base 1232 of the second insulating member 127, thereby reducing the assembly difficulty of the second insulating member 127. Meanwhile, in the embodiment in which the material strength of the first wall 1210 is relatively high, the connection of the second insulating member 127 and the first wall 1210 can disperse the assembly stress of the second insulating member 127 to a certain extent, thereby being conducive to improving the structural stability of the second insulating member 127 after assembly.

[0164] According to some embodiments of the present application, please refer to Figures 3-4 The battery monomer 12 further comprises a pressure relief mechanism 126, which is arranged on the first wall 1210.

[0165] In some embodiments, the first insulating member 123 is provided with a drainage hole 1236 penetrating through the thickness direction thereof, and the drainage hole 1236 corresponds to the position of the pressure relief mechanism 126. When the battery monomer 12 is in thermal runaway, part of the exhaust can pass through the drainage hole 1236 and be discharged from the battery monomer 12 through the pressure relief mechanism 126, thereby improving the pressure relief efficiency and reducing the risk of rapid melting and failure of the first insulating member 123 due to the excessive temperature inside the battery monomer 12 caused by the untimely pressure relief of the battery monomer 12.

[0166] In the above scheme, when the battery monomer 12 is in thermal runaway, part of the gas in the exhaust is discharged by the pressure relief mechanism 126 arranged on the first wall 1210. In the later stage of the thermal runaway of the battery monomer 12, the internal pressure of the battery monomer 12 is greater than the external pressure, and the electrode assembly 122 has a tendency to move close to the first wall 1210. At this time, the risk of abutment between the electrode assembly 122 and the first wall 1210 is relatively high. The arrangement of the second insulating member 127 can significantly reduce the risk of short circuit between the second part 1222 and the first wall 1210, thereby causing the battery monomer 12 to catch fire and explode.

[0167] According to some embodiments of the present application, please refer to Figures 3-5 The second part 1222 and the first tab 1224 are connected to form a first connection part, and the orthographic projection of the second insulating member 127 at least partially overlaps the first connection part in the same projection plane perpendicular to the thickness direction of the first wall 1210.

[0168] The second portion 1222 and the first tab 1224 can form the first connecting portion by riveting, welding or the like. In some embodiments, the second portion 1222 and the first tab 1224 form the first connecting portion by welding, and the first connecting portion is a welding joint formed by the two. The position where the welding joint is formed is generally less strong than other positions of the second portion 1222, and is more likely to deform, for example, arch, when the first current collecting member 1220 is subjected to force. Therefore, by setting the orthographic projection of the second insulating member 127 to at least partially overlap with the first connecting portion in the same projection plane perpendicular to the thickness direction of the first wall 1210, the risk of the first current collecting member 1220 shorting with the first wall 1210 to cause the battery monomer 12 to catch fire or explode can be significantly reduced.

[0169] In the above scheme, the position where the second portion 1222 and the first tab 1224 form the first connecting portion is generally less strong in structure, and is more likely to deform relatively greatly when the first current collecting member 1220 is subjected to force. The position where the first connecting portion short-circuits with the first wall 1210 has a higher risk. By setting the orthographic projection of the second insulating member 127 to at least partially overlap with the first connecting portion in the same projection plane perpendicular to the thickness direction of the first wall 1210, the risk of the first current collecting member 1220 shorting with the first wall 1210 to cause the battery monomer 12 to catch fire or explode can be significantly reduced.

[0170] According to some embodiments of the present application, please refer to Figures 3-5 The electrode assembly 122 is provided in plurality, the second portion 1222 and the first tab 1224 of the plurality of electrode assemblies 122 form a plurality of first connecting portions, and the second insulating member 127 is provided in plurality, and the plurality of second insulating members 127 correspond to the plurality of first connecting portions one by one.

[0171] In some embodiments, the plurality of electrode assemblies 122 are arranged along the stacking direction of the flat area of the electrode assembly 122.

[0172] In the above scheme, since the second insulating member 127 is arranged at the position of each first connecting portion, the risk of each first connecting portion short-circuiting with the first wall 1210 is reduced, thereby improving the reliability of the battery monomer 12.

[0173] According to some embodiments of the present application, please refer to Figures 3-5The electrode assembly 122 includes a second tab 1225. The battery cell 12 further includes a second electrode terminal 129, a second current collector 124, and a third insulating member 128. The second electrode terminal 129 is disposed on the first wall 1210. The second current collector 124 is disposed between the first wall 1210 and the electrode assembly 122, and includes a third portion 1241 and a fourth portion 1242 connected to each other, the third portion 1241 being connected to the second electrode terminal 129, and the fourth portion 1242 being connected to the second tab 1225. The third insulating member 128 is disposed between the fourth portion 1242 and the first wall 1210, and has a melting point greater than that of the first insulating member 123.

[0174] The first tab 1224 and the second tab 1225 have opposite polarities. In some embodiments, if the first current collector 1220 is used to output a positive electrode of the electrode assembly 122, the second current collector 124 is used to output a negative electrode of the electrode assembly 122.

[0175] In some embodiments, the first current collector 1220 and the second current collector 124 have the same structure.

[0176] In some embodiments, the third insulating member 128 has the same structure as the second insulating member 127.

[0177] The third insulating member 128 is disposed between the fourth portion 1242 and the first wall 1210, meaning that the third insulating member 128 can be connected to the fourth portion 1242, can be connected to the first wall 1210, or can be connected to both the fourth portion 1242 and the first wall 1210. Of course, the third insulating member 128 can also be neither connected to the fourth portion 1242 nor connected to the first wall 1210, but is located between the fourth portion 1242 and the first wall 1210.

[0178] The material of the third insulating member 128 can include, but is not limited to, perfluoroalkyl ethyl, polyimide, etc.

[0179] The melting point of the material of the third insulating member 128 is greater than that of the material of the first insulating member 123, that is, the third insulating member 128 is more resistant to high temperature and more difficult to melt than the first insulating member 123, and when the internal temperature of the battery cell 12 is too high, the first insulating member 123 will be softened or melted before the third insulating member 128.

[0180] It should be noted that the melting point of the material of the third insulating member 128 is the temperature at which the third insulating member 128 changes from a hard solid state to a liquid state or is softened and melted from a hard solid state to a molten viscous state.

[0181] In the above scheme, since the third insulating member 128 is arranged between the fourth portion 1242 and the first wall 1210, and the melting point of the third insulating member 128 is greater than the melting point of the first insulating member 123, the third insulating member 128 is more difficult to melt than the first insulating member 123. Even if the first insulating member 123 partially melts in the later stage of thermal runaway of the battery monomer 12, the third insulating member 128 can still play a role of insulating and isolating the fourth portion 1242 and the first wall 1210, thereby reducing the risk of short circuit between the second current collecting member 124 and the first wall 1210 causing the battery monomer 12 to catch fire and explode, and facilitating to improve the reliability of the battery monomer 12.

[0182] According to some embodiments of the present application, please refer to Figure 2 The present application provides a battery device 100 comprising the battery monomer 12 in one or more of the above embodiments.

[0183] In the above scheme, since the battery monomer 12 in one or more of the above embodiments has high reliability, the battery device 100 comprising the battery monomer 12 in one or more of the above embodiments also has high reliability.

[0184] According to some embodiments of the present application, please refer to Figure 1 The present application provides a battery device 100 comprising the battery monomer 12 in one or more of the above embodiments.

[0185] According to some embodiments of the present application, please refer to Figures 3-7 The present application provides a battery monomer 12, which comprises a shell 121, a first electrode terminal 125, a second electrode terminal, two electrode assemblies 122, a pressure relief mechanism 126, a first current collecting member 1220, a second current collecting member 124, a first insulating member 123, a second insulating member 127 and a third insulating member 128. The shell 121 comprises an end cover 1211 and a shell body 1212, and the shell body 1212 has an opening which is closed by the end cover 1211. The first electrode terminal 125 and the second electrode terminal 129 are arranged on the end cover 1211. The pressure relief mechanism 126 is arranged on the end cover 1211.

[0186] The two electrode assemblies 122 are arranged along the stacking direction of the flat area of the electrode assembly 122.

[0187] The electrode assembly 122 is arranged in the shell 121, and the electrode assembly 122 comprises a first tab 1224 and a second tab 1225, and the first tab 1224 and the second tab 1225 have opposite polarities.

[0188] The first current collecting member 1220 includes a first portion 1221 and two second portions 1222 corresponding to the first tabs 1224 of the two electrode assemblies 122, the first portion 1221 being connected with the first electrode terminal 125, and the second portions 1222 being connected with the first tabs 1224. The first insulating member 123 is arranged between the end cover 1211 and the electrode assemblies 122 to insulate and separate the end cover 1211 and the electrode assemblies 122. The second insulating member 127 is arranged between the second portions 1222 and the end cover 1211, and the melting point of the second insulating member 127 is greater than that of the first insulating member 123. The material of the second insulating member 127 is polyimide. The material of the first insulating member 123 is polypropylene. The second insulating member 127 is heat-fusedly connected with the first insulating member 123. The second current collecting member 124 includes a third portion 1241 and two fourth portions 1242 corresponding to the second tabs 1225 of the two electrode assemblies 122, the third portion 1241 being connected with the second electrode terminal 129, and the fourth portions 1242 being connected with the second tabs 1225. The third insulating member 128 is arranged between the fourth portions 1242 and the end cover 1211, and the melting point of the third insulating member 128 is greater than that of the first insulating member 123. The material of the third insulating member 128 is polyimide. The third insulating member 128 is heat-fusedly connected with the first insulating member 123.

[0189] The first insulating member 123 is provided with a plurality of through holes 1231 penetrating along the thickness direction of the end cover 1211, the second insulating member 127 is arranged in part of the through holes 1231, and the third insulating member 128 is arranged in part of the through holes 1231. The first insulating member 123 includes a base body 1232 and a boss 1233 protruding from the base body 1232 towards the electrode assemblies 122, and the boss 1233 abuts against the electrode assemblies 122. The through holes 1231 are arranged in the base body 1232. The base body 1232 has a first surface 12321 facing the electrode assemblies 122 and a second surface 12322 facing away from the electrode assemblies 122. The second insulating member 127 and the third insulating member 128 are flush with the first surface 12321 and the second surface 12322. In the same projection plane perpendicular to the thickness direction of the end cover 1211, the orthographic projection of the second portions 1222 is located within the orthographic projection of the second insulating member 127, and the orthographic projection of the fourth portions 1242 is located within the orthographic projection of the third insulating member 128.

[0190] In the later stage of thermal runaway of the battery cell 12, even if the first insulation piece 123 is melted, the second insulation piece 127 and the third insulation piece 128 can still insulate and separate the second part 1222 and the end cover 1211 and the fourth part 1242 and the end cover 1211, reducing the risk of short circuit between the second part 1222 and the end cover 1211 and the fourth part 1242 and the end cover 1211, causing the battery cell 12 to catch fire or explode.

[0191] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should be covered in the scope of the claims and the specification of the present application. In particular, as long as there is no structural conflict, each technical feature mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized by, The battery cell comprises: a housing comprising a first wall; an electrode assembly accommodated in the housing, the electrode assembly comprising a first tab; a first electrode terminal arranged on the first wall; a first current collecting member arranged between the first wall and the electrode assembly, the first current collecting member comprising a first portion and a second portion connected to each other, the first portion being connected to the first electrode terminal, and the second portion being connected to the first tab; a first insulating member arranged between the first wall and the electrode assembly to insulate the first wall and the electrode assembly from each other; and a second insulating member arranged between the second portion and the first wall, the second insulating member having a melting point greater than that of the first insulating member. The melting point of the second insulating member is greater than 250°C.

2. The battery cell of claim 1, wherein, The second insulating member is made of perfluoroalkyl ethylene or polyimide.

3. The battery cell of claim 1, wherein, The second insulating member is at least partially embedded in the first insulating member.

4. The battery cell of claim 1, wherein, The first insulating member is provided with a through hole penetrating in the thickness direction of the first wall, and the second insulating member is arranged in the through hole.

5. The battery cell of claim 4, wherein, The first insulating member comprises a base body and a boss protruding from the base body towards the electrode assembly, and the boss abuts against the electrode assembly.

6. The battery cell of claim 5, wherein, The through hole is arranged in the base body. In the thickness direction of the first wall, the thickness of the second insulating member is less than or equal to the thickness of the base body.

7. The battery cell of claim 6, wherein, The base body has a first surface facing the electrode assembly and a second surface facing away from the electrode assembly.

8. The battery cell of claim 6, wherein, The second insulating member does not protrude from the first surface, and / or the second insulating member does not protrude from the second surface. In the thickness direction of the first wall, the thickness of the second insulating member is H1, and 0.2mm≤H1≤2mm is satisfied.

9. The battery cell of claim 1, wherein, In the same projection plane perpendicular to the thickness direction of the first wall, the orthographic projection of the second portion is located within the orthographic projection of the second insulating member.

10. The battery cell of claim 1, wherein, The minimum distance between the edge of the orthographic projection of the second insulating member and the edge of the orthographic projection of the second portion is D1, and 1mm≤D1≤10mm is satisfied.

11. The battery cell of claim 10, wherein, The second insulating member is thermally fused to the first insulating member.

12. The battery cell of claim 1, wherein, The second insulating member is connected to the first wall.

13. The battery cell of claim 1, wherein, The battery cell further comprises a pressure relief mechanism arranged on the first wall.

14. The battery cell of claim 1, wherein, The second portion and the first tab form a first connection portion, and in the same projection plane perpendicular to the thickness direction of the first wall, the orthographic projection of the second insulating member at least partially overlaps the first connection portion.

15. The battery cell of claim 1, wherein, The electrode assembly is provided in plurality, the second portion and the first tab of the plurality of electrode assemblies form a plurality of first connection portions, and the second insulating member is provided in plurality, the plurality of second insulating members correspond to the plurality of first connection portions one by one.

16. The battery cell of claim 15, wherein, The electrode assembly comprises a second tab; 17. The battery cell of claim 1, wherein, The battery cell further comprises: a second electrode terminal arranged on the first wall; ​ a second current collecting member disposed between the first wall and the electrode assembly, the second current collecting member including a third portion and a fourth portion connected to each other, the third portion connected to the second electrode terminal, and the fourth portion connected to the second tab; and a third insulating member disposed between the fourth portion and the first wall, the third insulating member having a melting point greater than a melting point of the first insulating member.

18. A battery device, characterized by A battery cell comprising any one of claims 1-17.

19. An electrical device, comprising: A battery cell or a battery device of claim 18 for providing electrical energy to the electrical device.

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