Battery cell, battery device, and electric device

Abstract

The utility model discloses a battery monomer, a battery device and a power utilization device, and relates to the field of batteries, the battery monomer comprises a first pole piece, a second pole piece and a diaphragm, the diaphragm is arranged between the first pole piece and the second pole piece, an extension section is formed on the edge of at least one end of the diaphragm along the width direction of the diaphragm, and the extension section is arranged on the first pole piece and the second pole piece. The extending section extends out of at least one of the first pole piece and the second pole piece, and at least part of the outer surface of the extending section is provided with a heat insulation layer. Therefore, the thermal insulation layer is at least partially arranged on the outer surface of the extension section, so that the thermal insulation layer can reduce heat transfer to the extension section when a thermal spread test or a thermal runaway test is carried out, diaphragm shrinkage can be reduced, and the risk of short circuit in the single battery caused by contact of the first pole piece and the second pole piece is reduced; therefore, the thermal runaway risk of the battery monomer is reduced, and the use safety of the battery monomer is improved.

Description

TECHNICAL FIELD

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

[0002] In the related art, a diaphragm is arranged in the battery monomer and is arranged between the positive pole piece and the negative pole piece. When the existing diaphragm is subjected to heat spread testing or thermal runaway testing, the diaphragm is easily shrunk by heat, and the positive pole piece and the negative pole piece are easily contacted to cause short circuit in the battery monomer, thereby easily causing the risk of thermal runaway of the battery monomer and affecting the use safety of the battery monomer. CONTENT OF THE UTILITY MODEL

[0003] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, one purpose of the present application is to provide a battery monomer which is beneficial to reduce the shrinkage of the diaphragm, reduce the risk of short circuit in the battery monomer caused by the contact of the first pole piece and the second pole piece, thereby reducing the risk of thermal runaway of the battery monomer, and further improving the use safety of the battery monomer.

[0004] The present application further provides a battery device.

[0005] The present application further provides a power consumption device.

[0006] In a first aspect, the embodiments of the present application provide a battery monomer, comprising:

[0007] The first pole piece, the second pole piece and the diaphragm are arranged between the first pole piece and the second pole piece, at least one end edge of the diaphragm is formed with an overhanging section along the width direction of the diaphragm, the overhanging section protrudes from at least one of the first pole piece and the second pole piece, and the outer surface of the overhanging section is at least partially provided with a heat insulation layer.

[0008] In the above technical solution, by arranging the heat insulation layer at least partially on the outer surface of the overhanging section, the heat insulation layer has the functions of heat insulation and insulation. Compared with the prior art, the heat insulation layer can reduce the heat transfer to the overhanging section, reduce the heating of the diaphragm, and is beneficial to reduce the shrinkage of the diaphragm, so that the diaphragm reliably separates the first pole piece and the second pole piece, reduces the risk of short circuit in the battery monomer caused by the contact of the first pole piece and the second pole piece, thereby reduces the risk of thermal runaway of the battery monomer, reduces the risk of fire and explosion of the battery monomer, and further improves the use safety of the battery monomer. Moreover, after the diaphragm shrinks, the heat insulation layer at the overhanging section can separate the first pole piece and the second pole piece, achieving the effect of insulation between the first pole piece and the second pole piece after the diaphragm shrinks.

[0009] In some embodiments, the thermal insulation layer comprises a first thermal insulation layer, and at least one side outer surface of the overhanging section is provided with the first thermal insulation layer along the thickness direction of the diaphragm.

[0010] In the above technical solution, by providing the first thermal insulation layer on at least one side outer surface of the overhanging section along the thickness direction of the diaphragm, when the heat spread test or the thermal runaway test is performed, the thermal insulation layer can further reduce the heat transfer to the overhanging section, further reduce the heating of the diaphragm, and more facilitate to reduce the shrinkage of the diaphragm, further reduce the risk of short circuit inside the battery cell caused by the contact between the first pole piece and the second pole piece, thereby further improving the use safety of the battery cell. And, it is also convenient to fix the first thermal insulation layer to the overhanging section, thereby facilitating to improve the assembly efficiency of the diaphragm and the first thermal insulation layer.

[0011] In some embodiments, the thermal insulation layer comprises a second thermal insulation layer, and an end surface of the overhanging section is provided with the second thermal insulation layer along the width direction of the diaphragm.

[0012] In the above technical solution, by providing the second thermal insulation layer on the end surface of the overhanging section along the width direction of the diaphragm, it is beneficial to improve the setting area of the thermal insulation layer at the overhanging section, and when the heat spread test or the thermal runaway test is performed, the first thermal insulation layer and the second thermal insulation layer can simultaneously reduce the heat transfer to the overhanging section, further reduce the heating of the diaphragm, and more facilitate to reduce the shrinkage of the diaphragm, further reduce the risk of short circuit inside the battery cell caused by the contact between the first pole piece and the second pole piece, thereby further improving the use safety of the battery cell.

[0013] In some embodiments, the first thermal insulation layer and the second thermal insulation layer are connected.

[0014] In the above technical solution, by connecting the first thermal insulation layer and the second thermal insulation layer, the thermal insulation layer can be directly wrapped at the overhanging section, which is more convenient to fix the thermal insulation layer to the overhanging section, thereby more facilitating to improve the assembly efficiency of the diaphragm and the thermal insulation layer. And, by connecting the first thermal insulation layer and the second thermal insulation layer, the first thermal insulation layer and the second thermal insulation layer can be reliably fixed to the overhanging section, thereby reducing the risk of falling off of the first thermal insulation layer and the second thermal insulation layer, and facilitating to improve the product quality of the battery cell.

[0015] In some embodiments, the first thermal insulation layer and the second thermal insulation layer are integrally formed.

[0016] In the technical solution, the first thermal insulation layer and the second thermal insulation layer are integrally formed, which is beneficial to improve the connection strength of the first thermal insulation layer and the second thermal insulation layer, reduce the risk of fracture at the connection of the first thermal insulation layer and the second thermal insulation layer, and make the first thermal insulation layer and the second thermal insulation layer more reliably fixed to the extension section, thereby further reducing the risk of falling off of the first thermal insulation layer and the second thermal insulation layer, and more beneficial to improve the product quality of the battery monomer. Moreover, the thermal insulation layer can be directly wrapped around the extension section by simply bending the thermal insulation layer, which is more convenient for fixing the thermal insulation layer to the extension section, thereby more beneficial to improve the assembly efficiency of the separator and the thermal insulation layer.

[0017] In some embodiments, along the width direction of the separator, the outer end of the first thermal insulation layer is flush with the end surface of the extension section.

[0018] In the technical solution, along the width direction of the separator, the outer end of the first thermal insulation layer is flush with the end surface of the extension section, which can make the first thermal insulation layer abut the end edge of the separator, make the first thermal insulation layer be reasonably arranged, and reduce the influence of the first thermal insulation layer on the lithium ion transmission at the middle position of the separator, thereby being beneficial to make the battery monomer meet the working performance.

[0019] In some embodiments, along the width direction of the separator, the width dimension of the first thermal insulation layer is greater than or equal to 0.3 mm and less than or equal to 4 mm.

[0020] In the technical solution, along the width direction of the separator, the width dimension of the first thermal insulation layer is greater than or equal to 0.3 mm and less than or equal to 4 mm, which can reduce the shrinkage of the separator, reduce the influence of the first thermal insulation layer on the lithium ion transmission at the middle position of the separator, and meet the insulation requirement between the first and second electrode sheets, thereby making the width dimension of the first thermal insulation layer be reasonably arranged.

[0021] In some embodiments, along the thickness direction of the separator, the thickness dimension of the first thermal insulation layer is greater than or equal to 6 μm and less than or equal to 12 μm.

[0022] In the technical solution, along the thickness direction of the separator, the thickness dimension of the first thermal insulation layer is greater than or equal to 6 μm and less than or equal to 12 μm, which makes the thickness dimension of the first thermal insulation layer appropriate, can make the first thermal insulation layer meet the thermal insulation requirement, and when the orthographic projection of the separator and the orthographic projection of at least one of the first and second electrode sheets have an overlapping area along the arrangement direction of the first and second electrode sheets, makes the spacing distance between the first and second electrode sheets appropriate, and is beneficial to improve the energy density of the battery monomer.

[0023] In some embodiments, the thermal insulation layer is bonded to the extension section.

[0024] In the technical solution, the heat insulation layer is attached to the extension section, so that the heat insulation layer is stably installed on the extension section, the risk of separation of the heat insulation layer and the extension section is reduced, and the heat insulation layer is conveniently installed on the extension section, and the assembly efficiency of the heat insulation layer and the extension section is improved.

[0025] In some embodiments, the heat insulation layer is configured as a heat insulation adhesive layer.

[0026] In the technical solution, the heat insulation layer is configured as a heat insulation adhesive layer, so that the heat insulation layer is directly attached to the outer surface of the extension section, the heat insulation layer is conveniently installed on the extension section, the heat insulation adhesive layer has good heat insulation performance and good thermal stability, and the shrinkage of the diaphragm can be effectively reduced when the diaphragm is heated.

[0027] In some embodiments, along the width direction of the diaphragm, the end of the first pole piece extends beyond the end of the second pole piece, and the inner end of the first heat insulation layer is located inside the end of the first pole piece.

[0028] In the technical solution, along the width direction of the diaphragm, the inner end of the first heat insulation layer is located inside the end of the first pole piece, so that the first heat insulation layer can abut against the first pole piece, the first heat insulation layer can effectively separate the first pole piece and the second pole piece, the insulation performance between the first pole piece and the second pole piece is improved, and the risk of short circuit inside the battery cell caused by contact between the first pole piece and the second pole piece is further reduced.

[0029] In some embodiments, the inner end of the first heat insulation layer is located outside the end of the second pole piece.

[0030] In the technical solution, the inner end of the first heat insulation layer is located outside the end of the second pole piece, so that the first heat insulation layer does not occupy the space between the first pole piece and the second pole piece, the spacing distance between the first pole piece and the second pole piece is appropriate, and the energy density of the battery cell is further improved.

[0031] In some embodiments, the inner end of the first heat insulation layer abuts against the second pole piece.

[0032] In the technical solution, the inner end of the first heat insulation layer abuts against the second pole piece, so that the first heat insulation layer is limited in cooperation with the second pole piece, and the shrinkage of the diaphragm is limited.

[0033] In a second aspect, the embodiments of the present application also provide a battery device comprising the battery cell.

[0034] In a third aspect, the embodiments of the present application also provide a power consumption device comprising the battery device.

[0035] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0036] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description, taken in conjunction with the following drawings in which:

[0037] Figure 1 is a schematic view of a vehicle according to embodiments of the present application;

[0038] Figure 2 is an exploded view of a battery device according to embodiments of the present application;

[0039] Figure 3 is a sectional view of a battery cell according to embodiments of the present application;

[0040] Figure 4 is an exploded view of a battery cell according to embodiments of the present application;

[0041] Figure 5 is an assembly schematic view of a first electrode sheet, a second electrode sheet, and a separator according to embodiments of the present application;

[0042] Figure 6 is a schematic view of a separator according to some embodiments of the present application;

[0043] Figure 7 is a schematic view of a separator according to some other embodiments of the present application;

[0044] Figure 8 is a schematic view of a separator according to some other embodiments of the present application.

[0045] Reference Signs:

[0046] Battery cell 100;

[0047] First electrode sheet 10; second electrode sheet 20;

[0048] Separator 30; protruding section 31;

[0049] Thermal insulation layer 40; first thermal insulation layer 41; second thermal insulation layer 42;

[0050] Electrode assembly 50;

[0051] Battery device 200; box 201; first box 202; second box 203;

[0052] Vehicle 300; controller 301; motor 302. DETAILED DESCRIPTION

[0053] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0054] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used in the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion. The terms "first", "second" and the like in the specification and claims of the present application and the above description of drawings are used to distinguish different objects, not to describe a particular order or primary and secondary relationship.

[0055] In the present application, the phrase "embodiments" means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears at various places in the specification does not necessarily all refer to the same embodiments, nor are they necessarily mutually exclusive or alternative embodiments to each other.

[0056] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mount", "connect", "connection", "attach" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be direct connection, or indirect connection through intermediate medium, or internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0057] In the present application, the term "and / or" is only a description of the association relationship between the associated objects, which means that there can be three kinds of relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in the present application generally represents an "or" relationship between the front and rear associated objects.

[0058] In the embodiments of the present application, the same reference signs represent the same components, and for the sake of brevity, detailed description of the same components is omitted in different embodiments. It should be understood that the thickness, length and width of various components in the embodiments of the present application shown in the drawings, and the overall thickness, length and width of the integrated device are only exemplary and should not constitute any limitation on the present application.

[0059] All embodiments and optional embodiments of the present application can be combined with each other to form new technical solutions if there is no special description.

[0060] All technical features and optional technical features of the present application can be combined with each other to form new technical solutions if there is no special description.

[0061] “Multiple” appearing in the present application refers to two or more (including two).

[0062] 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.

[0063] The battery cell can be 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. The embodiments of the present application are not limited thereto.

[0064] The battery cell can be in the shape of a cylinder, a flat body, a cuboid or other shapes, etc. The embodiments of the present application are not limited thereto. The battery cell is generally divided into three types according to the packaging method: cylindrical battery cell, square battery cell and soft package battery cell, and the embodiments of the present application are not limited thereto.

[0065] The battery apparatus mentioned in the embodiments of the present application can include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly can include a plurality of battery cells connected in series, parallel or mixed connection through a busbar component.

[0066] In some embodiments, the battery cell assembly is generally formed by arranging a plurality of battery cells.

[0067] 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 an independent module. As an example, the battery module can be formed by bundling a plurality of battery cells with a cable tie.

[0068] In some embodiments, the battery apparatus can be a battery pack, which includes a box and one or more battery cell assemblies, and the battery cell assemblies are accommodated in the box.

[0069] As an example, the battery cell assembly can be a battery module, which can be accommodated in the box by fixing the battery module in the box.

[0070] As an example, the battery cell assembly can also be housed in the case by directly fixing a plurality of battery cells to the case.

[0071] As an example, the case can include a first case and a second case. The first case and the second case are fastened so that an enclosed space (i.e., a mounting compartment) is formed inside the case to receive the battery cell assembly. The enclosed here means covered or closed, which can be sealed or unsealed. The first case can be a top cover or a bottom plate.

[0072] As an example, the case can include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are connected with the frame, respectively, so that an enclosed space is formed inside the case to receive the battery cell assembly.

[0073] In some embodiments, the case can be part of a chassis structure of a vehicle. For example, part of the case can be at least part of a floor of the vehicle, or part of the case can be at least part of a cross beam and a longitudinal beam of the vehicle.

[0074] The technical solutions described in the embodiments of the present application are applicable to various electric devices using battery cells, such as mobile phones, portable devices, notebook computers, electric vehicles, electric toys, electric tools, vehicles, ships, and spacecraft, such as aircraft, rockets, space shuttles, and spacecraft.

[0075] The battery cell includes a shell, an electrode assembly, and an electrolyte. The shell is used to contain the electrode assembly and the electrolyte. The electrode assembly is composed of a positive electrode tab, a negative electrode tab, and a separator. The battery cell mainly relies on the movement of metal ions between the positive electrode tab and the negative electrode tab to work. The positive electrode tab includes an anode current collector and an anode active material layer, and the anode active material layer is coated on the surface of the anode current collector. The anode current collector that has not been coated with the anode active material layer protrudes from the anode current collector that has been coated with the anode active material layer, and the anode current collector that has not been coated with the anode active material layer serves as an anode tab. Taking a lithium-ion battery as an example, the material of the anode current collector can be aluminum, and the anode active material can be lithium cobaltate, lithium iron phosphate, ternary lithium, or lithium manganate, etc. The negative electrode tab includes a cathode current collector and a cathode active material layer, and the cathode active material layer is coated on the surface of the cathode current collector. The cathode current collector that has not been coated with the cathode active material layer protrudes from the cathode current collector that has been coated with the cathode active material layer, and the cathode current collector that has not been coated with the cathode active material layer serves as a cathode tab. The material of the cathode current collector can be copper, and the cathode active material can be carbon or silicon, etc. In order to ensure that no fuse occurs when passing a large current, the number of anode tabs is multiple and stacked together, and the number of cathode tabs is multiple and stacked together.

[0076] The material of the diaphragm can be PP (polypropylene) or PE (polyethylene) or the like. In addition, the electrode assembly can be a roll structure or a stacked structure, and the embodiments of the present application are not limited thereto.

[0077] In recent years, new energy vehicles have made a leap in development. In the field of electric vehicles, battery devices play an irreplaceable important role as the power source of electric vehicles. As a core component of new energy vehicles, battery devices have high requirements in terms of reliability.

[0078] A diaphragm is arranged in the battery monomer, and the diaphragm is arranged between the positive pole piece and the negative pole piece. When the existing diaphragm is subjected to heat spread test or thermal runaway test, the diaphragm is easily shrunk by heat, and the positive pole piece and the negative pole piece are easily contacted, which causes short circuit in the battery monomer, thereby easily causing thermal runaway risk of the battery monomer, and affecting the use safety of the battery monomer.

[0079] Based on the above consideration, in order to solve the problem that the diaphragm is shrunk by heat and causes short circuit in the battery monomer. After deep research, a battery monomer is designed, which comprises: a first pole piece, a second pole piece and a diaphragm, the diaphragm is arranged between the first pole piece and the second pole piece, at least one end edge of the diaphragm forms an extension along the width direction of the diaphragm, the extension extends out of at least one of the first pole piece and the second pole piece, and the outer surface of the extension is at least partially provided with a heat insulation layer. By arranging the heat insulation layer at least partially on the outer surface of the extension, when the heat spread test or the thermal runaway test is carried out, the heat insulation layer can reduce the heat transfer to the extension, which is conducive to reducing the shrinkage of the diaphragm, reducing the risk of short circuit in the battery monomer caused by the contact between the first pole piece and the second pole piece, thereby reducing the risk of thermal runaway of the battery monomer, and further improving the use safety of the battery monomer.

[0080] Please refer to Figure 1 , Figure 1 A structural schematic diagram of a vehicle 300 is provided for some embodiments of the present application. The vehicle 300 can be a fuel vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle or a range extended vehicle, etc. The battery device 200 is installed on the chassis of the vehicle 300. The battery device 200 can be used for power supply of the vehicle 300, for example, the battery device 200 can be used as the operating power source of the vehicle 300. The vehicle 300 can further include a controller 301 and a motor 302, and the controller 301 is used to control the battery device 200 to supply power to the motor 302, for example, for the working power demand of the vehicle 300 during starting, navigation and driving.

[0081] In some embodiments of the present application, the battery device 200 can not only serve as the operating power source of the vehicle 300, but also serve as the driving power source of the vehicle 300, replacing or partially replacing the fuel or natural gas to provide driving power for the vehicle 300.

[0082] Reference will be made below to Figures 2-8 The battery cell 100 according to the embodiments of the present application is described below, which is installed in the battery device 200, and the battery device 200 can be installed in the chassis of the vehicle 300.

[0083] As Figures 5-8 shown, the battery cell 100 according to the embodiments of the present application comprises a first electrode sheet 10, a second electrode sheet 20, and a separator 30, the separator 30 is arranged between the first electrode sheet 10 and the second electrode sheet 20, at least one end edge of the separator 30 forms an overhanging section 31 along the width direction of the separator 30, the overhanging section 31 overhangs at least one of the first electrode sheet 10 and the second electrode sheet 20, and the outer surface of the overhanging section 31 is at least partially provided with a thermal insulation layer 40.

[0084] The battery cell 100 can be a cylindrical battery cell 100, or a square battery cell 100, or a stacked battery cell 100. The first electrode sheet 10 is one of a positive electrode sheet and a negative electrode sheet, and the second electrode sheet 20 is the other of the positive electrode sheet and the negative electrode sheet. The present application takes the first electrode sheet 10 as the negative electrode sheet and the second electrode sheet 20 as the positive electrode sheet as an example for description. The first electrode sheet 10, the second electrode sheet 20, and the separator 30 are assembled to form an electrode assembly 50. As an example, the first electrode sheet 10, the second electrode sheet 20, and the separator 30 are arranged in layers to form a stacked electrode assembly 50. As another example, the first electrode sheet 10, the second electrode sheet 20, and the separator 30 are wound to form a wound electrode assembly 50.

[0085] The separator 30 is located between the first electrode sheet 10 and the second electrode sheet 20, and the separator 30 separates the first electrode sheet 10 and the second electrode sheet 20. Along the width direction of the separator 30, the width direction of the separator 30 refers to the Y direction in Figure 5 , that is, one end edge of the separator 30 forms the overhanging section 31, or both end edges of the separator 30 form the overhanging section 31. The present application takes the example that both end edges of the separator 30 form the overhanging section 31 along the width direction of the separator 30 for description. The size of the overhanging section 31 along the width direction of the separator 30 can be reasonably selected according to actual conditions.

[0086] The protruding section 31 protrudes at least one of the first pole piece 10 and the second pole piece 20. It is to be noted that, as an example, the protruding section 31 protrudes at the end of the first pole piece 10 and the end of the second pole piece 20 when the ends of the first pole piece 10 and the second pole piece 20 are aligned along the width direction of the diaphragm 30. As another example, the protruding section 31 protrudes at the end of the first pole piece 10 and the ends of the second pole piece 20 when the two ends of the second pole piece 20 both protrude at the first pole piece 10 along the width direction of the diaphragm 30. As another example, the protruding section 31 protrudes at the end of the first pole piece 10 and does not protrude at the end of the second pole piece 20 when the two ends of the second pole piece 20 both protrude at the first pole piece 10 along the width direction of the diaphragm 30.

[0087] The outer surface of the protruding section 31 is at least partially provided with a heat insulation layer 40. The heat insulation layer 40 is resistant to high temperature, has heat insulation and insulation effects, and can be made of a heat insulation material. The heat insulation material refers to a material capable of blocking heat transfer. The heat insulation layer 40 can be made of heat insulation glue, rock wool board, vacuum board, polyimide glue, PET glue, silicone glue, etc. However, the application is not limited thereto. The heat insulation layer 40 can also be made of other materials as long as it has the effects of being resistant to high temperature, heat insulation and insulation. The outer surface of part of the protruding section 31 is provided with the heat insulation layer 40, or the entire outer surface of the protruding section 31 is provided with the heat insulation layer 40. The heat insulation layer 40 can be bonded to the outer surface of the protruding section 31, or the heat insulation layer 40 can be installed on the outer surface of the protruding section 31 through fasteners.

[0088] In the above technical solution, by providing the heat insulation layer 40 on at least part of the outer surface of the protruding section 31, the heat insulation layer 40 has heat insulation and insulation effects. Compared with the prior art, when the heat spread test or the thermal runaway test is performed, the heat insulation layer 40 can reduce the heat transfer to the protruding section 31, reduce the heating of the diaphragm 30, and help to reduce the shrinkage of the diaphragm 30. The diaphragm 30 can reliably separate the first pole piece 10 and the second pole piece 20, reduce the risk of short circuit caused by the contact between the first pole piece 10 and the second pole piece 20, reduce the risk of thermal runaway of the battery monomer 100, reduce the risk of fire and explosion of the battery monomer 100, and thus improve the use safety of the battery monomer 100. Moreover, after the diaphragm 30 shrinks, the heat insulation layer 40 at the protruding section 31 can separate the first pole piece 10 and the second pole piece 20, achieving the effect of insulating the first pole piece 10 and the second pole piece 20 after the diaphragm 30 shrinks.

[0089] According to some embodiments of the application, as shown in Figure 6 and Figure 7 The heat insulation layer 40 includes a first heat insulation layer 41. At least one side of the outer surface of the protruding section 31 is provided with the first heat insulation layer 41 along the thickness direction of the diaphragm 30.

[0090] The heat insulation layer 40 includes a first heat insulation layer 41, which extends along the thickness direction of the diaphragm 30. The thickness direction of the diaphragm 30 refers to... Figure 5 In the Z direction, at least one outer surface of the protruding section 31 is provided with a first heat insulation layer 41, that is, along the thickness direction of the diaphragm 30, such as Figure 6 As shown, as an example, a first heat insulation layer 41 is provided on one outer surface of the protruding section 31. Or, as... Figure 7 As shown, as another example, both outer surfaces of the protruding section 31 are provided with a first heat insulation layer 41. Furthermore, the first heat insulation layer 41 may cover the entire side surface of the protruding section 31.

[0091] In the above technical solution, along the thickness direction of the separator 30, a first heat insulation layer 41 is provided on at least one outer surface of the extension section 31. During thermal propagation testing or thermal runaway testing, the heat insulation layer 40 can further reduce the transfer of heat to the extension section 31, further reduce the heating of the separator 30, and further reduce the shrinkage of the separator 30. This further reduces the risk of short circuit inside the battery cell 100 caused by the contact between the first electrode 10 and the second electrode 20, thereby further improving the safety of the battery cell 100. In addition, it is also convenient to fix the first heat insulation layer 41 to the extension section 31, which is conducive to improving the assembly efficiency of the separator 30 and the first heat insulation layer 41.

[0092] According to some embodiments of this application, such as Figure 8 As shown, the heat insulation layer 40 includes a second heat insulation layer 42, which is provided on the end face of the protruding section 31 along the width direction of the diaphragm 30.

[0093] The heat insulation layer 40 includes a second heat insulation layer 42, which is provided on the outer end face of the protruding section 31 along the width direction of the diaphragm 30. As an example, a first heat insulation layer 41 is provided on one outer surface of the protruding section 31 along the thickness direction of the diaphragm 30, and a second heat insulation layer 42 is provided on the outer end face of the protruding section 31 along the width direction of the diaphragm 30. As another example, such as... Figure 8 As shown, along the thickness direction of the diaphragm 30, the outer surfaces of both sides of the protruding section 31 are provided with a first heat insulation layer 41, and along the width direction of the diaphragm 30, the outer end face of the protruding section 31 is provided with a second heat insulation layer 42.

[0094] In the technical solution, the second thermal insulation layer 42 is arranged on the end surface of the protruding section 31 along the width direction of the diaphragm 30, which is beneficial to increase the arrangement area of the thermal insulation layer 40 at the protruding section 31. During the heat spread test or the thermal runaway test, the first thermal insulation layer 41 and the second thermal insulation layer 42 can simultaneously reduce the heat transfer to the protruding section 31, further reduce the heating of the diaphragm 30, and more beneficially reduce the shrinkage of the diaphragm 30, further reduce the risk of short circuit in the battery monomer 100 caused by the contact between the first pole piece 10 and the second pole piece 20, and further improve the use safety of the battery monomer 100.

[0095] According to some embodiments of the present application, as shown in Figure 8 The first thermal insulation layer 41 and the second thermal insulation layer 42 are connected.

[0096] For example, the first thermal insulation layer 41 and the second thermal insulation layer 42 can be connected by adhesion. Alternatively, as another example, as shown in Figure 8 The first thermal insulation layer 41 and the second thermal insulation layer 42 can be integrally formed. The present application takes the first thermal insulation layer 41 and the second thermal insulation layer 42 integrally formed as an example for description, and at this time, the thermal insulation layer 40 can be directly wrapped at the protruding section 31.

[0097] In the technical solution, the first thermal insulation layer 41 and the second thermal insulation layer 42 are connected, which can directly wrap the thermal insulation layer 40 at the protruding section 31, and is more beneficial to fix the thermal insulation layer 40 at the protruding section 31, thereby more beneficially improving the assembly efficiency of the diaphragm 30 and the thermal insulation layer 40. Moreover, the connection of the first thermal insulation layer 41 and the second thermal insulation layer 42 can reliably fix the first thermal insulation layer 41 and the second thermal insulation layer 42 at the protruding section 31, and reduce the risk of falling off of the first thermal insulation layer 41 and the second thermal insulation layer 42, thereby beneficially improving the product quality of the battery monomer 100.

[0098] According to some embodiments of the present application, as shown in Figure 8 The first thermal insulation layer 41 and the second thermal insulation layer 42 are integrally formed. The first thermal insulation layer 41 and the second thermal insulation layer 42 form the thermal insulation layer 40, and the thermal insulation layer 40 is formed by the bending connection of the first thermal insulation layer 41 and the second thermal insulation layer 42.

[0099] In the technical solution, the first thermal insulation layer 41 and the second thermal insulation layer 42 are integrally formed, which is beneficial to improve the connection strength of the first thermal insulation layer 41 and the second thermal insulation layer 42, reduce the risk of breakage at the connection of the first thermal insulation layer 41 and the second thermal insulation layer 42, make the first thermal insulation layer 41 and the second thermal insulation layer 42 more reliable and fixed on the extension section 31, and further reduce the risk of falling of the first thermal insulation layer 41 and the second thermal insulation layer 42, thereby more beneficial to improve the product quality of the battery monomer 100. Moreover, as long as the thermal insulation layer 40 is bent, the thermal insulation layer 40 can be directly wrapped at the extension section 31, which is more convenient for fixing the thermal insulation layer 40 on the extension section 31, thereby more beneficial to improve the assembly efficiency of the diaphragm 30 and the thermal insulation layer 40.

[0100] According to some embodiments of the present application, as shown in Figures 6-8 The outer end of the first thermal insulation layer 41 is flush with the end face of the extension section 31 along the width direction of the diaphragm 30.

[0101] The outer end face of the first thermal insulation layer 41 is coplanar with the end face of the corresponding extension section 31 along the width direction of the diaphragm 30, in other words, the outer end face of the first thermal insulation layer 41 is arranged opposite to the end face of the corresponding extension section 31 along the thickness direction of the diaphragm 30.

[0102] In the technical solution, the outer end of the first thermal insulation layer 41 is flush with the end face of the extension section 31 along the width direction of the diaphragm 30, which can make the first thermal insulation layer 41 abut the end edge of the diaphragm 30, make the first thermal insulation layer 41 be reasonably arranged, reduce the influence of the first thermal insulation layer 41 on the lithium ion transmission at the middle position of the diaphragm 30, and thereby be beneficial to make the battery monomer 100 meet the working performance.

[0103] According to some embodiments of the present application, the width size of the first thermal insulation layer 41 is greater than or equal to 0.3 mm and less than or equal to 4 mm along the width direction of the diaphragm 30.

[0104] The width size of the first thermal insulation layer 41 is L along the width direction of the diaphragm 30, and satisfies the relationship: 0.3 mm≤L≤4 mm. The width size of the first thermal insulation layer 41 can be set to 0.3 mm, 0.4 mm, 0.5 mm, 0.55 mm, 1 mm, 2 mm, 3 mm, 4 mm, etc. The width size of the first thermal insulation layer 41 can be reasonably selected according to actual needs. It should be noted that if the width size of the first thermal insulation layer 41 is greater than 4 mm, the lithium ion transmission at the middle position of the diaphragm 30 is affected, and if the width size of the first thermal insulation layer 41 is less than 0.3 mm, it is not conducive to reducing the shrinkage of the diaphragm 30, nor is it conducive to the insulation between the first and second pole pieces 10 and 20.

[0105] In the technical solution, along the width direction of the diaphragm 30, the width size of the first thermal insulation layer 41 is greater than or equal to 0.3 mm and less than or equal to 4 mm, which meets the requirement of reducing the shrinkage of the diaphragm 30 and can reduce the influence of the first thermal insulation layer 41 on the lithium ion transmission at the middle position of the diaphragm 30, and can also meet the insulation requirement between the first electrode sheet 10 and the second electrode sheet 20, so that the width size of the first thermal insulation layer 41 is reasonably set.

[0106] According to some embodiments of the present application, along the thickness direction of the diaphragm 30, the thickness size of the first thermal insulation layer 41 is greater than or equal to 6 μm and less than or equal to 12 μm.

[0107] As shown in Figure 5 and Figure 6 , along the thickness direction of the diaphragm 30, the width size of the first thermal insulation layer 41 is D, which meets the relationship: 6 μm≤D≤12 μm, and the thickness size of the first thermal insulation layer 41 can be set to 6 μm, 6.5 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, etc., and the thickness size of the first thermal insulation layer 41 can be reasonably selected according to actual needs.

[0108] It should be noted that if the thickness size of the first thermal insulation layer 41 is less than 6 μm, the thermal insulation effect of the first thermal insulation layer 41 is not good, which is not conducive to reducing the shrinkage of the diaphragm 30. When the orthographic projection of the diaphragm 30 has an overlapping area with at least one of the orthographic projection of the first electrode sheet 10 and the orthographic projection of the second electrode sheet 20 along the arrangement direction of the first electrode sheet 10 and the second electrode sheet 20, if the thickness size of the first thermal insulation layer 41 is greater than 12 μm, it will affect the spacing distance between the first electrode sheet 10 and the second electrode sheet 20, which will increase the spacing distance between the first electrode sheet 10 and the second electrode sheet 20, and affect the energy density of the battery monomer 100.

[0109] In the technical solution, along the thickness direction of the diaphragm 30, the thickness size of the first thermal insulation layer 41 is greater than or equal to 6 μm and less than or equal to 12 μm, which makes the thickness size of the first thermal insulation layer 41 appropriate, so that the first thermal insulation layer 41 can meet the thermal insulation requirement, and when the orthographic projection of the diaphragm 30 has an overlapping area with at least one of the orthographic projection of the first electrode sheet 10 and the orthographic projection of the second electrode sheet 20 along the arrangement direction of the first electrode sheet 10 and the second electrode sheet 20, the spacing distance between the first electrode sheet 10 and the second electrode sheet 20 is appropriate, which is conducive to improving the energy density of the battery monomer 100.

[0110] According to some embodiments of the present application, the thermal insulation layer 40 is bonded to the protruding section 31. As an example, the thermal insulation layer 40 can be bonded to the protruding section 31 by adhesive. As another example, the thermal insulation layer 40 is configured as a thermal insulation adhesive layer, and in this embodiment, the thermal insulation layer 40 is directly bonded to the outer surface of the protruding section 31.

[0111] In the technical solution, the heat insulation layer 40 is bonded to the extension section 31, so that the heat insulation layer 40 is stably installed on the extension section 31, the risk of separation of the heat insulation layer 40 and the extension section 31 is reduced, and the heat insulation layer 40 is conveniently installed on the extension section 31, and the assembly efficiency of the heat insulation layer 40 and the extension section 31 is improved.

[0112] According to some embodiments of the present application, the heat insulation layer 40 is configured as a heat insulation adhesive layer. The heat insulation layer 40 is composed of a heat insulation adhesive layer having heat insulation and insulation effects, and the heat insulation layer 40 can be made of polyimide adhesive (i.e., PI adhesive), PET adhesive, silicone adhesive, etc. The heat insulation adhesive layer has excellent thermal stability, mechanical properties, and chemical stability, and the heat insulation adhesive layer has good heat insulation performance.

[0113] In the technical solution, the heat insulation layer 40 is configured as a heat insulation adhesive layer, so that the heat insulation layer 40 is directly bonded to the outer surface of the extension section 31, the heat insulation layer 40 is conveniently installed on the extension section 31, the heat insulation adhesive layer has good heat insulation performance, has good thermal stability, and can effectively reduce the shrinkage of the diaphragm 30 when the diaphragm 30 is heated.

[0114] According to some embodiments of the present application, as shown in Figure 5 According to some embodiments of the present application, as shown in

[0115] According to some embodiments of the present application, as shown in

[0116] In the technical solution, along the width direction of the diaphragm 30, the inner end of the first thermal insulation layer 41 is located inside the end of the first pole piece 10, the first thermal insulation layer 41 can be in abutment with the first pole piece 10, the first thermal insulation layer 41 can effectively separate the first pole piece 10 and the second pole piece 20, which is conducive to improving the insulation performance between the first pole piece 10 and the second pole piece 20, and further reduces the risk of short circuit inside the battery monomer 100 caused by the contact between the first pole piece 10 and the second pole piece 20.

[0117] According to some embodiments of the present application, the inner end of the first thermal insulation layer 41 is located outside the end of the second pole piece 20.

[0118] In the technical solution, along the width direction of the diaphragm 30, the inner end of the first thermal insulation layer 41 is located inside the corresponding end of the first pole piece 10, and the inner end of the first thermal insulation layer 41 is located outside the corresponding end of the second pole piece 20.

[0119] In the technical solution, by locating the inner end of the first thermal insulation layer 41 outside the end of the second pole piece 20, the first thermal insulation layer 41 does not occupy the space between the first pole piece 10 and the second pole piece 20, the spacing distance between the first pole piece 10 and the second pole piece 20 is appropriate, which is more conducive to improving the energy density of the battery monomer 100.

[0120] According to some embodiments of the present application, the inner end of the first thermal insulation layer 41 is in abutment with the second pole piece 20.

[0121] In the technical solution, along the width direction of the diaphragm 30, the inner end of the first thermal insulation layer 41 is in abutment with the corresponding end of the second pole piece 20, and the inner end of the first thermal insulation layer 41 is in abutment with the corresponding end of the second pole piece 20. By abutting the inner end of the first thermal insulation layer 41 with the end of the second pole piece 20, the first thermal insulation layer 41 and the second pole piece 20 can be limited and cooperated, thereby being conducive to limiting the shrinkage of the diaphragm 30.

[0122] The battery device 200 according to the embodiments of the present application includes the battery monomer 100 of the above-mentioned embodiments. The battery device 200 can include a box body 201, the box body 201 can include a first box body 202 and a second box body 203, the first box body 202 and the second box body 203 are buckled so that a closed mounting cavity is formed inside the box body 201, the first box body 202 can be located above the second box body 203, and the battery monomer 100 is mounted in the mounting cavity.

[0123] According to the battery device 200 provided by the embodiment of the present application, the battery monomer 100 in the above embodiment is provided with the heat insulation layer 40 at least partially on the outer surface of the protruding section 31, and the heat insulation layer 40 has the heat insulation and insulation effects. Compared with the prior art, when the heat spread test or the thermal runaway test is performed, the heat insulation layer 40 can reduce the heat transfer to the protruding section 31, reduce the heat absorption of the diaphragm 30, and help to reduce the shrinkage of the diaphragm 30, so that the diaphragm 30 can reliably separate the first pole piece 10 and the second pole piece 20, reduce the risk of short circuit caused by the contact between the first pole piece 10 and the second pole piece 20 in the battery monomer 100, reduce the risk of thermal runaway of the battery monomer 100, reduce the risk of fire and explosion of the battery monomer 100, and thus improve the use safety of the battery monomer 100. Moreover, after the shrinkage of the diaphragm 30, the heat insulation layer 40 at the protruding section 31 can separate the first pole piece 10 and the second pole piece 20, realize the insulation effect between the first pole piece 10 and the second pole piece 20 after the shrinkage of the diaphragm 30, and thus improve the use safety of the battery device 200.

[0124] According to the power utilization device provided by the embodiment of the present application, the battery device 200 in the above embodiment is included.

[0125] According to the power utilization device provided by the embodiment of the present application, the battery device 200 in the above embodiment is included, and the use safety of the power utilization device can be improved.

[0126] According to some embodiments of the present application, as shown in Figure 5 and Figure 8 The present application provides a battery monomer 100, which comprises a first pole piece 10, a second pole piece 20 and a diaphragm 30. The diaphragm 30 is arranged between the first pole piece 10 and the second pole piece 20. Along the width direction of the diaphragm 30, both ends of the diaphragm 30 are provided with protruding sections 31, and the protruding sections 31 protrude from the first pole piece 10 and the second pole piece 20. Along the width direction of the diaphragm 30, the end of the first pole piece 10 protrudes from the end of the second pole piece 20, the inner end of the first heat insulation layer 41 is located on the inner side of the end of the first pole piece 10, and the inner end of the first heat insulation layer 41 is located on the outer side of the end of the second pole piece 20. The outer surface of the protruding section 31 is provided with a heat insulation layer 40. Along the thickness direction of the diaphragm 30, the outer surfaces of both sides of the protruding section 31 are provided with the first heat insulation layer 41, along the width direction of the diaphragm 30, the end surface of the protruding section 31 is provided with a second heat insulation layer 42, and the first heat insulation layer 41 and the second heat insulation layer 42 are integrally formed.

[0127] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0128] In the description of the application, reference has been made to descriptive terms such as "one embodiment", "some embodiments", "an embodiment", "example", "specific example" or "some examples" etc. It is emphasized that each of these terms refers to a specific feature, structure, material or characteristic described in connection with a particular embodiment or example. The descriptive terms are not necessarily referring to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0129] While embodiments of the application have been shown and described, it is to be understood that the application is not limited to the details of the embodiments described, since the scope of the application is defined with respect to the appended claims.

Claims

1. A battery cell, characterized by, The battery cell includes: a first electrode tab, a second electrode tab, and a separator disposed between the first electrode tab and the second electrode tab, at least one end edge of the separator being formed with an overhanging section that overhangs at least one of the first electrode tab and the second electrode tab, an outer surface of the overhanging section being at least partially provided with a thermal insulation layer.

2. The battery cell of claim 1, wherein, The thermal insulation layer includes a first thermal insulation layer provided on at least one side outer surface of the overhanging section in a thickness direction of the separator.

3. The battery cell of claim 2, wherein, The thermal insulation layer includes a second thermal insulation layer provided on an end surface of the overhanging section in a width direction of the separator.

4. The battery cell of claim 3, wherein, The first thermal insulation layer and the second thermal insulation layer are connected.

5. The battery cell of claim 3, wherein, The first thermal insulation layer and the second thermal insulation layer are integrally formed.

6. The battery cell of claim 2, wherein, An outer end of the first thermal insulation layer is flush with the end surface of the overhanging section in the width direction of the separator.

7. The battery cell of claim 6, wherein, A width dimension of the first thermal insulation layer is greater than or equal to 0.3 mm and less than or equal to 4 mm in the width direction of the separator.

8. The battery cell of claim 2, wherein, A thickness dimension of the first thermal insulation layer is greater than or equal to 6 μm and less than or equal to 12 μm in the thickness direction of the separator.

9. The battery cell of claim 1, wherein, The thermal insulation layer is bonded to the overhanging section.

10. The battery cell of any one of claims 1-9, wherein, The thermal insulation layer is configured as a thermal insulation adhesive layer.

11. The battery cell of any one of claims 2-8, wherein, An end portion of the first electrode tab overhangs an end portion of the second electrode tab in the width direction of the separator, and an inner end of the first thermal insulation layer is located inside the end portion of the first electrode tab.

12. The battery cell of claim 11, wherein, The inner end of the first thermal insulation layer is located outside the end portion of the second electrode tab.

13. The battery cell of claim 12, wherein, The inner end of the first thermal insulation layer abuts against the second electrode tab.

14. A battery device characterized by comprising: The battery cell according to any one of claims 1 to 13.

15. An electrical device, comprising: The battery device according to claim 14.

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