Battery monomer, battery device and electric equipment

Abstract

The utility model relates to the technical field of battery production, in particular to a battery monomer, a battery device and electric equipment. The battery monomer comprises a shell, a first insulating film and an electrode assembly, the first insulating film is arranged on the inner side of the shell, the first insulating film comprises a base material layer and an expansion layer, the base material layer comprises a first part and a second part which are connected with each other, the first part and the second part are sequentially arranged in the height direction of the battery monomer, the first part is positioned above the second part; the expansion layer is arranged inside and / or on the surface of the second part; the electrode assembly is provided inside the first insulating film. When the electrode assembly is punctured, the leaked electrolyte is absorbed through the expansion layer arranged in the second part and / or on the surface of the second part, and the probability that the electrolyte flows out of the shell is reduced.

Description

Technical Field

[0001] This application relates to the field of battery manufacturing technology, and in particular to a battery cell, battery device, and electrical equipment. Background Technology

[0002] This section provides only background information relevant to this disclosure and is not necessarily prior art.

[0003] With the increasing maturity of new energy technologies, new energy vehicles and other electrical equipment are gradually entering the public eye. The core technology of new energy vehicles lies in the battery device, and the safety and stability of the battery device directly determine the performance of the entire vehicle.

[0004] A battery device typically comprises multiple battery cells, each including a housing and a first insulating film located inside the housing. When the electrode assembly of a battery cell is punctured, electrolyte leakage from the housing is likely to occur. Utility Model Content

[0005] In view of the above problems, this application provides a battery cell, a battery device, and an electrical device, which solves the problem that electrolyte leakage from the casing is easy when the electrode assembly of the battery cell is punctured in the prior art.

[0006] A first aspect of the embodiments of this application provides a battery cell comprising:

[0007] case;

[0008] A first insulating film is disposed on the inner side of the housing. The first insulating film includes a substrate layer and an expansion layer. The substrate layer includes a first portion and a second portion that are interconnected. The first portion and the second portion are sequentially arranged along the height direction of the battery cell, with the first portion located above the second portion. The expansion layer is disposed inside and / or on the surface of the second portion.

[0009] Electrode assembly, the electrode assembly is disposed inside the first insulating film.

[0010] In the embodiments of this application, a first insulating film is provided on the inner side of the casing. The first insulating film includes a substrate layer and an expansion layer. The substrate layer includes a first part and a second part that are connected to each other. The first part and the second part are arranged sequentially along the height direction of the battery cell, wherein the first part is located above the second part. The expansion layer is provided inside and / or on the surface of the second part. In the event of a puncture in the electrode assembly, the expansion layer provided inside and / or on the surface of the second part can absorb the leaked electrolyte, reducing the probability of electrolyte flowing out of the casing.

[0011] In some embodiments of this application, the number of expansion layers is one, and the expansion layers are continuously distributed inside and / or on the surface of the second part; the expansion layers are disposed opposite to the side and bottom surfaces of the electrode assembly.

[0012] The embodiments of this application set the number of expansion layers to one, and the expansion layers are continuously distributed inside and / or on the surface of the second part; the expansion layers are arranged opposite to the side and bottom surfaces of the electrode assembly, so that after the electrode assembly leaks electrolyte, the leaked electrolyte can be absorbed in time by the expansion layers arranged opposite to the electrode assembly, reducing the probability of electrolyte flowing out of the shell.

[0013] In some embodiments of this application, the number of expansion layers is two or more, and the two or more expansion layers are spaced apart inside and / or on the surface of the second part; the expansion layers are disposed opposite to a portion of the side surface and / or a portion of the bottom surface of the electrode assembly.

[0014] The embodiments of this application, by having two or more expansion layers, and the two or more expansion layers being spaced apart inside and / or on the surface of the second part; the expansion layers being disposed opposite to a portion of the side surface and / or the bottom surface of the electrode assembly, can timely absorb the leaked electrolyte from the electrode assembly through the expansion layers disposed opposite to the electrode assembly, thereby reducing the probability of electrolyte flowing out of the casing.

[0015] In some embodiments of this application, the shell has a rectangular structure, the rectangular structure includes multiple surfaces, the multiple surfaces include a first surface, the first surface is the surface with the largest area among the multiple surfaces; an expansion layer is disposed opposite to the first surface.

[0016] The embodiments of this application configure the housing as a rectangular structure, wherein the rectangular structure includes multiple surfaces, including a first surface, which is the surface with the largest area among the multiple surfaces. An expansion layer is disposed opposite to the first surface, which means that the expansion layer is disposed corresponding to the first surface of the housing. Thus, an expansion layer is disposed between the surface with the largest area of ​​the electrode assembly and the first surface, and the absorption of electrolyte is achieved through the expansion layer.

[0017] In some embodiments of this application, there are two first surfaces, and the two first surfaces are arranged opposite to each other; the two expansion layers and the two first surfaces are respectively arranged opposite to each other.

[0018] In the embodiments of this application, by having two first surfaces arranged opposite each other, and two expansion layers and two first surfaces arranged opposite each other, expansion layers can be provided between the two surfaces with the largest area of ​​the electrode assembly and the two first surfaces, thereby achieving the absorption of electrolyte through the two expansion layers and improving the absorption efficiency of leaked electrolyte.

[0019] In some embodiments of this application, the expanded layer includes one of a oriented polystyrene layer, a biaxially oriented polypropylene layer, a biaxially oriented nylon layer, and a biaxially oriented polyester layer.

[0020] The embodiments of this application include an expansion layer comprising one of a oriented polystyrene layer, a biaxially oriented polypropylene layer, a biaxially oriented nylon layer, and a biaxially oriented polyester layer. This allows for the timely absorption of electrolyte using oriented polystyrene, biaxially oriented polypropylene, biaxially oriented nylon, or biaxially oriented polyester materials, thereby reducing the probability of spontaneous combustion caused by leaked electrolyte coming into contact with air.

[0021] In some embodiments of this application, the substrate layer includes one of a polyethylene terephthalate layer and a polypropylene layer.

[0022] The embodiments of this application include either a polyethylene terephthalate layer or a polypropylene layer in the substrate layer. This allows the polyethylene terephthalate material or the polypropylene material to provide enhanced strength and insulation properties in the electrolyte, thereby achieving insulation between two adjacent battery cells.

[0023] In some embodiments of this application, the battery cell further includes a top cover assembly; the first part forms a rectangular cylindrical structure, and the rectangular cylindrical structure is inserted and engaged with the top cover assembly.

[0024] The embodiments of this application provide a top cover assembly and a first part that forms a rectangular cylindrical structure. The rectangular cylindrical structure is inserted into the top cover assembly, thereby achieving the enclosure of the housing and protecting the electrode assembly.

[0025] In some embodiments of this application, the top cover assembly includes a lower plastic layer; a portion of the lower plastic layer is connected to the rectangular cylindrical structure by heat fusion.

[0026] The embodiments of this application achieve a sealed connection between the lower plastic and the rectangular cylindrical structure by including a lower plastic in the top cover assembly and connecting the lower plastic portion to the rectangular cylindrical structure by heat fusion, thereby sealing the housing and protecting the electrode assembly.

[0027] A second aspect of the embodiments of this application provides a battery device comprising the battery cells mentioned in the above embodiments.

[0028] A third aspect of the embodiments of this application provides an electrical device that includes the battery cell mentioned in the above embodiments, the battery cell being used to supply power to the electrical device.

[0029] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0030] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0031] Figure 1 This is a schematic diagram of the structure of a battery device provided in some embodiments of this application;

[0032] Figure 2 This is a schematic diagram of the structure of an electrical device provided in some embodiments of this application;

[0033] Figure 3 for Figure 1 A schematic diagram of the exploded structure of a single battery cell in the battery device shown;

[0034] Figure 4 for Figure 3 A schematic diagram of the structure of the first insulating film of the battery cell shown in the figure;

[0035] Figure 5 for Figure 4 The diagram shows the structure of a single battery cell with the first insulating film in an unfolded state.

[0036] Figure 6 for Figure 5 The cross-sectional view of the first insulating film of the battery cell shown along section AA;

[0037] Figure 7 for Figure 6 A partially enlarged structural diagram of the first insulating film of the battery cell at point B;

[0038] Figure 8 for Figure 6 Another schematic diagram of the structure of the first insulating film of the battery cell shown;

[0039] Figure 9 for Figure 6 Another structural schematic diagram of the first insulating film of the battery cell shown;

[0040] Figure 10 for Figure 3 A three-dimensional structural diagram of the housing of a single battery cell in the battery device shown;

[0041] The attached figures are labeled as follows:

[0042] 100. Battery device; 200. Electrical equipment; 300. Controller; 400. Motor;

[0043] 10. Battery cell; 11. Top cover assembly; 111. Top cover plate; 112. Top cover body; 1121. Lower plastic; 113. Adapter piece; 12. Electrode assembly; 13. Housing; 131. First surface; 132. Second surface; 14. Support plate; 141. Connection hole; 15. First insulating film; 151. Substrate layer; 1511. First part; 1512. Second part; 152. Expansion layer; 16. Second insulating film;

[0044] 20. Container assembly; 21. First container; 22. Second container; 23. Storage space;

[0045] XX, the length direction of the battery cell;

[0046] YY, the width direction of the battery cell;

[0047] ZZ, the height direction of a single battery cell. Detailed Implementation

[0048] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0049] 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 pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0050] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0051] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0052] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0053] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0054] In the description of the embodiments of this application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0055] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0056] Currently, judging from market trends, the application of battery devices is becoming increasingly widespread. Battery devices are not only used in energy storage power systems such as hydropower, thermal power, wind power, and solar power plants, but also widely applied in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of battery device applications, market demand is also constantly increasing.

[0057] The battery devices described in this application can be used, but are not limited to, in electrical equipment such as vehicles, ships, or aircraft. Such electrical equipment can be composed of battery cells and battery devices as described in this application.

[0058] In this application embodiment, the electrical devices using battery devices as power sources can be, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Among them, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0059] It should be understood that the technical solutions described in the embodiments of this application are not limited to the battery devices and electrical equipment described above, but can also be applied to all batteries including housings and electrical equipment using batteries.

[0060] The battery apparatus mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells connected in series, parallel, or mixed connections via a busbar.

[0061] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0062] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form an independent module. As another example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0063] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cells housed within the housing.

[0064] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0065] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0066] As an example, the enclosure may include a first enclosure and a second enclosure. The first enclosure and the second enclosure are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first enclosure may be a top cover or a bottom plate.

[0067] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0068] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0069] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly consists of a positive electrode, a negative electrode, and a separator. The battery cell primarily functions by the movement of metal ions between the positive and negative electrodes. The positive electrode includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector. Current collectors without the positive active material layer protrude beyond those with the coating. These uncoated current collectors are stacked together to form the positive electrode tab. Taking a lithium-ion battery as an example, the positive current collector can be made of aluminum, and the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode includes a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative current collector. Current collectors without the negative active material layer protrude beyond those with the coating. These uncoated current collectors are stacked together to form the negative electrode tab. The negative current collector can be made of copper, and the negative active material can be carbon or silicon, etc. The separator can be made of PP (polypropylene) or PE (polyethylene), etc. Furthermore, the electrode assembly can be a wound structure or a stacked structure; the embodiments of this application are not limited to these.

[0070] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use individual battery cells, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships, and spacecraft. For example, spacecraft include airplanes, rockets, space shuttles, and spacecraft.

[0071] A battery device typically comprises multiple battery cells, each including a housing and a first insulating film located inside the housing. When the electrode assembly of a battery cell is punctured, electrolyte leakage from the housing is likely to occur.

[0072] To address this problem, embodiments of this application propose a battery cell comprising a casing, a first insulating film, and an electrode assembly. The first insulating film is disposed inside the casing and includes a substrate layer and an expansion layer. The substrate layer includes a first portion and a second portion that are interconnected. The first portion and the second portion are sequentially arranged along the height direction of the battery cell, with the first portion located above the second portion. The expansion layer is disposed inside and / or on the surface of the second portion. The electrode assembly is disposed inside the first insulating film. Therefore, in the event of a puncture in the electrode assembly, the expansion layer disposed inside and / or on the surface of the second portion absorbs the leaked electrolyte, reducing the probability of electrolyte flowing out of the casing.

[0073] The battery cells in the embodiments of this application can be used in electrical equipment such as vehicles, or installed in products such as energy storage devices.

[0074] The structures in the embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0075] Please refer to Figure 2 , Figure 2 This is a schematic diagram of the structure of an electrical device 200 provided in some embodiments of this application. The electrical device 200 can be a vehicle, which can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 100 is installed inside the vehicle, and the battery device 100 can be located at the bottom, front, or rear of the vehicle. The battery device 100 can be used to power the vehicle; for example, the battery device 100 can serve as the vehicle's operating power source. The electrical device 200 may also include a controller 300 and a motor 400. The controller 300 is used to control the battery device 100 to supply power to the motor 400, for example, to meet the power needs of the vehicle during starting, navigation, and driving.

[0076] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the electrical equipment 200, but also as the driving power source for the electrical equipment 200, replacing or partially replacing fuel oil or natural gas to provide driving power for the electrical equipment 200.

[0077] like Figure 1As shown, the battery device 100 mentioned in the embodiments of this application may include one or more battery cell assemblies 10 for providing voltage and capacity. A battery cell assembly 10 may include multiple battery cells 10, which are connected in series, parallel, or mixed connections via a busbar.

[0078] In some embodiments, the battery cell assembly is typically formed by arranging multiple battery cells 10.

[0079] As an example, the battery cell 10 assembly can be a battery module, which is formed by arranging and fixing multiple battery cells 10 together to form an independent module. As an example, the battery module can be formed by bundling multiple battery cells 10 together with cable ties.

[0080] In some embodiments, such as Figure 1 As shown, Figure 1 The present invention provides a schematic diagram of the structure of a battery device 100 according to some embodiments of the present application. The battery device 100 may be a battery pack, which includes a housing assembly 20 and one or more battery cell 10 assemblies, with the battery cell 10 assemblies housed in the housing assembly 20.

[0081] As an example, such as Figure 1 As shown, the housing assembly 20 may include a first housing 21 and a second housing 22. The first housing 21 and the second housing 22 are fastened together, forming a closed receiving space 23 inside the housing assembly 20 to house the individual battery cells 10. Here, "closed" refers to covering or closing, which can be either sealed or unsealed. The first housing 21 is a top cover, and the second housing 22 is a bottom plate. Alternatively, the first housing 21 can be a bottom plate, and the second housing 22 can be a top cover.

[0082] Reference Figure 3 As shown, the battery cell 10 includes a housing 13, a first insulating film 15, and an electrode assembly 12. The first insulating film 15 is disposed inside the housing 13 and includes a substrate layer 151 and an expansion layer 152. The substrate layer 151 includes a first portion 1511 and a second portion 1512 that are connected to each other. The first portion 1511 and the second portion 1512 are arranged sequentially along the height direction of the battery cell 10, wherein the first portion 1511 is located above the second portion 1512. The expansion layer 152 is disposed inside and / or on the surface of the second portion 1512. The electrode assembly 12 is disposed inside the first insulating film 15.

[0083] It should be noted that the first insulating film 15 here can also be called a Mylar film, which is located on the inner surface of the housing 13 and serves an insulating function. Figure 4 As shown, the first insulating film 15 has a rectangular structure with an opening at the top in the battery cell 10, and can be disposed on the outer surface of the electrode assembly 12 or on the inner surface of the housing 13.

[0084] Continue to refer to Figure 3 As shown, the height direction of the battery cell 10 is... Figure 3 In the ZZ direction, the length direction of the battery cell 10 is the XX direction, and the width direction of the battery cell is the YY direction.

[0085] In this embodiment, a first insulating film 15 is provided on the inner side of the housing 13. The first insulating film 15 includes a substrate layer 151 and an expansion layer 152. The substrate layer 151 includes a first part 1511 and a second part 1512 that are connected to each other. The first part 1511 and the second part 1512 are arranged sequentially along the height direction of the battery cell 10, wherein the first part 1511 is located above the second part 1512. The expansion layer 152 is provided inside and / or on the surface of the second part 1512. In the event that the electrode assembly 12 is punctured, the expansion layer 152 provided inside and / or on the surface of the second part 1512 can absorb the leaked electrolyte and reduce the probability of the electrolyte flowing out of the housing 13.

[0086] Optionally, such as Figure 3 As shown, the battery cell 10 also includes a support plate 14 and a second insulating film 16. The support plate 14 is located at the bottom of the battery cell 10 and can support the housing 13. The support plate 14 has two connection holes 141 for connecting to the housing 13. The second insulating film 16, also known as the blue film, has an insulating function.

[0087] Optionally, such as Figure 3 As shown, the battery cell 10 also includes a top cover assembly 11. The first part 1511 forms a rectangular cylindrical structure, which is inserted into the top cover assembly 11. The top cover assembly 11 is located on top of the battery cell 10, therefore, the first part 1511 is located above the second part 1512.

[0088] Specifically, such as Figure 3 As shown, the top cover assembly 11 includes a top cover plate 111, a top cover body 112, and an adapter plate 113. The top cover plate 111 is disposed on the top cover body 112, and the electrode assembly 12 is sealed in the housing 13 by the top cover body 112. These are all common components, and the function of each component and the connection relationship between the components will not be described in detail here.

[0089] In the embodiments of this application, by setting a top cover assembly 11 and the first part 1511 forming a rectangular cylindrical structure, the rectangular cylindrical structure and the top cover assembly 11 are inserted and matched, so that the shell 13 can be sealed by the top cover assembly 11 and the rectangular cylindrical structure, thus forming protection for the electrode assembly 12.

[0090] It should be added that the electrode assembly 12 is the core component for the rechargeable battery to achieve its charging and discharging functions. The electrode assembly 12 includes a positive electrode, a negative electrode, and a separator, with the separator separating the positive and negative electrode. The positive electrode includes a positive current collector and a positive active material layer coated on the surface of the positive current collector. The positive current collector can be aluminum foil, and the positive active material layer includes ternary materials, lithium manganese oxide, or lithium iron phosphate. The negative electrode includes a negative current collector and a negative active material layer coated on the surface of the negative current collector. The negative current collector can be copper foil, and the negative active material layer includes graphite or silicon.

[0091] The electrode assembly 12 can be a wound structure. Specifically, there is one positive electrode and one negative electrode, and both the positive and negative electrode are strip-shaped structures. The positive electrode, the separator, and the negative electrode are stacked in sequence and wound two or more times to form the electrode assembly 12. In the preparation of the electrode assembly 12, the electrode assembly 12 can be first wound into a hollow cylindrical structure, and then flattened into a flat shape.

[0092] Alternatively, the electrode assembly 12 can also be a stacked structure. Specifically, multiple positive electrode sheets and multiple negative electrode sheets are provided, with the multiple positive and negative electrode sheets stacked alternately, and a separator separating the positive and negative electrode sheets.

[0093] In some embodiments of this application, the top cover assembly 11 includes a lower plastic 1121; a portion of the lower plastic 1121 is connected to the rectangular cylindrical structure by heat fusion. The lower plastic 1121 can be integrated onto the top cover body 112, or it can be independently disposed from the top cover body 112.

[0094] The lower plastic part 1121 here can be connected to the rectangular cylindrical structure by hot melting, such as by welding.

[0095] In the embodiments of this application, by including a lower plastic 1121 in the top cover assembly 11 and connecting a portion of the lower plastic 1121 to the rectangular cylindrical structure by heat fusion, a sealed connection can be achieved between the lower plastic 1121 and the rectangular cylindrical structure, thereby sealing the housing 13 and protecting the electrode assembly 12.

[0096] It is important to emphasize that the expansion layer 152 is positioned away from the first part 1511 and will not affect the insertion of the electrode assembly 12 into the housing 13.

[0097] like Figures 5 to 9 As shown, the structure of the first insulating film 15 will be described in detail below.

[0098] In some embodiments of this application, such as Figure 5 As shown, there is one expansion layer 152, and the expansion layer 152 is continuously distributed inside and / or on the surface of the second part 1512; the expansion layer 152 is disposed opposite to the side and bottom surfaces of the electrode assembly 12, wherein the expansion layer 152 is located in Figure 5 Within the dashed box.

[0099] It should be noted that the electrode assembly 12 has four sides, and the bottom surface is located at the bottom of the electrode assembly 12. The expansion layer 152 can be disposed opposite to the sides and bottom surface of the electrode assembly 12.

[0100] It should be noted that the continuous distribution of the expansion layer 152 on the surface of the second part 1512 means that the expansion layer 152 is continuously distributed on the inner surface of the second part 1512 and / or the expansion layer 152 is continuously distributed on the outer surface of the second part 1512. Figure 6 In this configuration, the expansion layer 152 is located on the inner surface of the second portion 1512. Figure 8 In this process, the expansion layer 152 is located inside the second part 1512. The method of placing the expansion layer 152 inside the second part 1512 can be to make the expansion layer 152 using an expansion material, then melt the substrate layer 151 into a liquid, pour the liquid onto the outside of the expansion layer 152, and after cooling, the expansion layer 152 can be placed inside the substrate layer 151.

[0101] In the embodiments of this application, the number of expansion layers 152 is set to one, and the expansion layers 152 are continuously distributed inside and / or on the surface of the second part 1512. The expansion layers 152 are disposed opposite to the side and bottom surfaces of the electrode assembly 12. After the electrode assembly 12 leaks electrolyte, the expansion layers 152 disposed opposite to the electrode assembly 12 can absorb the leaked electrolyte in a timely manner, reducing the probability of electrolyte flowing out of the housing 13.

[0102] It should be noted that the expansion layer 152 can also be set as two, with the two expansion layers 152 respectively set on the outer surface and the inner surface of the second part 1512, and the expansion layers 152 are continuously distributed on the outer surface of the second part 1512 and also continuously distributed on the inner surface of the second part 1512.

[0103] Alternatively, the expansion layer 152 may also be disposed inside the second portion 1512, and the expansion layer 152 may be continuously distributed inside the second portion 1512.

[0104] Alternatively, the number of expansion layers 152 is three, wherein two expansion layers 152 are respectively disposed on the outer surface and the inner surface of the second part 1512, and the third expansion layer 152 is located inside the second part 1512, wherein the three expansion layers 152 are continuously distributed.

[0105] In some embodiments of this application, such as Figure 9 As shown, there are two or more expansion layers 152, and the two or more expansion layers 152 are spaced apart inside and / or on the surface of the second part 1512; the expansion layers 152 are disposed opposite to a portion of the side surface and / or a portion of the bottom surface of the electrode assembly 12. Figure 9 In the middle, there are two expansion layers 152, which are arranged at intervals and distributed at intervals on the inner surface of the second part 1512.

[0106] It should be noted that, in Figure 9 The electrode assembly 12 has two expansion layers 152, which are respectively disposed opposite to a portion of the side surface of the electrode assembly 12. Alternatively, the expansion layers 152 can also be disposed opposite to a portion of the bottom surface of the electrode assembly 12. Alternatively, both a portion of the side surface and a portion of the bottom surface of the electrode assembly 12 can be simultaneously provided with expansion layers 152 opposite to each other.

[0107] Specifically, the number of expansion layers 152 is at least two, and they may also be distributed at intervals within the second part 1512.

[0108] Specifically, the number of expansion layers 152 is at least two, and the at least two expansion layers 152 are distributed at intervals on the outer surface of the second part 1512.

[0109] As one example, these three distribution methods can also coexist, enabling faster absorption of leaked electrolyte.

[0110] In this embodiment, by distributing at least two expansion layers 152 at intervals and setting the expansion layers 152 opposite to a portion of the side surface and / or bottom surface of the electrode assembly 12, the leaked electrolyte can be absorbed in a timely manner by the expansion layers 152 that are opposite to the electrode assembly 12 after the electrode assembly 12 leaks electrolyte, reducing the probability of electrolyte flowing out of the casing 13 and reducing the amount of material used in the expansion layers 152, thereby reducing the cost of the battery cell 10.

[0111] In some embodiments of this application, such as Figure 10 As shown, the shell 13 has a rectangular structure, which includes multiple surfaces, including a first surface 131, which is the surface with the largest area among the multiple surfaces; an expansion layer 152 is disposed opposite to the first surface 131.

[0112] Specifically, the first surface 131 corresponds to the large surface of the electrode assembly 12, and an expansion layer 152 is provided between the first surface 131 and the large surface of the electrode assembly 12.

[0113] Optionally, the plurality of surfaces also includes a second surface 132, wherein there are also two second surfaces 132, and the first surface 131 and the second surface 132 form a rectangular tube structure.

[0114] In the embodiments of this application, the housing 13 is configured as a rectangular structure, wherein the rectangular structure includes multiple surfaces, including a first surface 131, which is the surface with the largest area among the multiple surfaces. An expansion layer 152 is disposed opposite to the first surface 131, so that the expansion layer 152 is disposed corresponding to the first surface 131 of the housing 13. Thus, an expansion layer 152 is disposed between the surface with the largest area of ​​the electrode assembly 12 and the first surface 131, and the absorption of electrolyte is achieved through the expansion layer 152.

[0115] In some embodiments of this application, such as Figure 9 As shown, there are two first surfaces 131, and the two first surfaces 131 are arranged opposite to each other; the two expansion layers 152 and the two first surfaces 131 are respectively arranged opposite to each other.

[0116] Specifically, the first surface 131 corresponds to the large surface of the electrode assembly 12, and an expansion layer 152 is disposed between the first surface 131 and the large surface of the electrode assembly 12. There are two first surfaces 131, two expansion layers 152, and two large surfaces of the electrode assembly 12. In this case, an expansion layer 152 is disposed between the large surface of the electrode assembly 12 and the opposite first surface 131, and each expansion layer 152 can absorb the electrolyte leaked from the electrode assembly 12.

[0117] In the embodiments of this application, by having two first surfaces 131 arranged opposite each other, and two expansion layers 152 arranged opposite each other to the two surfaces 131 with the largest area of ​​the electrode assembly 12, expansion layers 152 are respectively provided between the two surfaces 131 and the two first surfaces 131. The absorption of electrolyte is achieved through the two expansion layers 152, thereby improving the absorption efficiency of leaked electrolyte.

[0118] In some embodiments of this application, the expanded layer 152 includes one of an oriented polystyrene layer, a biaxially oriented polypropylene layer, a biaxially oriented nylon layer, and a biaxially oriented polyester layer.

[0119] Specifically, the expansion layer 152 includes an oriented polystyrene layer, which can be made of oriented polystyrene (OPS) material. The expansion layer 1521412 can be a thin film structure made of oriented polystyrene through an oriented stretching process.

[0120] Specifically, the expansion layer 152 includes a biaxially oriented polypropylene layer, which can be made of biaxially oriented polypropylene (BOPP) material. The molten polypropylene is first made into a sheet or thick film by passing the molten polymer through a narrow die head, then stretched in a dedicated stretching machine, and then made into a film by appropriate cooling or heat treatment or special processing (such as corona treatment, coating, etc.).

[0121] Specifically, the expansion layer 152 includes a biaxially oriented nylon layer, which may be made of biaxially oriented nylon material.

[0122] Specifically, the expansion layer 152 includes a biaxially oriented polyester layer, which may be made of biaxially oriented polyester material.

[0123] The embodiments of this application include an expansion layer 152 comprising one of an oriented polystyrene layer, a biaxially oriented polypropylene layer, a biaxially oriented nylon layer, and a biaxially oriented polyester layer. This allows for the timely absorption of electrolyte using oriented polystyrene, biaxially oriented polypropylene, biaxially oriented nylon, or biaxially oriented polyester materials, thereby reducing the probability of spontaneous combustion caused by leaked electrolyte coming into contact with air.

[0124] In some embodiments of this application, the substrate layer 151 includes one of a polyethylene terephthalate layer and a polypropylene layer.

[0125] Specifically, the substrate layer 151 includes a polyethylene terephthalate layer, which can be made of polyethylene terephthalate (PET) material. It has good strength and toughness and good processing performance, making it easy to process into a film or sheet structure.

[0126] Specifically, the substrate layer 151 includes a polypropylene layer, which may be made of polypropylene material, which has good heat resistance, chemical resistance, impact resistance and mechanical strength, and is inexpensive.

[0127] In the embodiments of this application, by including either a polyethylene terephthalate layer or a polypropylene layer in the substrate layer 151, the polyethylene terephthalate material or the polypropylene material can be used to provide strength and insulation properties in the electrolyte, thereby achieving insulation between two adjacent battery cells 10.

[0128] Optionally, the first insulating film 15 contacts the inner surface of the housing 13. Alternatively, the first insulating film 15 contacts the side and bottom surfaces of the electrode assembly 12 and wraps around the side and bottom surfaces of the electrode assembly 12. In either case, the first insulating film 15 can be connected to the inner surface of the housing 13 or connected to the electrode assembly 12.

[0129] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application.

[0130] A first aspect of this application provides a battery cell 10, including a housing 13, a first insulating film 15, and an electrode assembly 12. The first insulating film 15 is disposed inside the housing 13, and includes a substrate layer 151 and an expansion layer 152. The substrate layer 151 includes a first portion 1511 and a second portion 1512 connected to each other, and the first portion 1511 and the second portion 1512 are sequentially arranged along the height direction of the battery cell 10, wherein the first portion 1511 is located above the second portion 1512; the expansion layer 152 is disposed inside and / or on the surface of the second portion 1512; and the electrode assembly 12 is disposed inside the first insulating film 15. Further, there is one expansion layer 152, and the expansion layer 152 is continuously distributed inside and / or on the surface of the second portion 1512; the expansion layer 152 is disposed opposite to the side and bottom surfaces of the electrode assembly 12. Further, the number of expansion layers 152 is two or more, and the two or more expansion layers 152 are spaced apart inside and / or on the surface of the second part 1512; the expansion layers 152 are disposed opposite to a portion of the side surface and / or a portion of the bottom surface of the electrode assembly 12. Further, the housing 13 has a rectangular structure, the rectangular structure includes multiple surfaces, the multiple surfaces include a first surface 131, the first surface 131 is the surface with the largest area among the multiple surfaces; one expansion layer 152 and the first surface 131 are disposed opposite to each other. Further, the number of first surfaces 131 is two, and the two first surfaces 131 are disposed opposite to each other; the two expansion layers 152 and the two first surfaces 131 are respectively disposed opposite to each other. Further, the expansion layer 152 includes one of oriented polystyrene layer, biaxially oriented polypropylene layer, biaxially oriented nylon layer and biaxially oriented polyester layer. Further, the substrate layer 151 includes one of polyethylene terephthalate layer and polypropylene layer. Furthermore, the battery cell 10 also includes a top cover assembly 11; the first part 1511 forms a rectangular cylindrical structure, which is inserted into the top cover assembly 11. Furthermore, the top cover assembly 11 includes a lower plastic 1121; a portion of the lower plastic 1121 is connected to the rectangular cylindrical structure by heat fusion.

[0131] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A battery cell, characterized in that, include: case; A first insulating film is disposed on the inner side of the housing. The first insulating film includes a substrate layer and an expansion layer. The substrate layer includes a first portion and a second portion that are interconnected. The first portion and the second portion are sequentially arranged along the height direction of the battery cell, wherein the first portion is located above the second portion. The expansion layer is disposed inside and / or on the surface of the second portion. An electrode assembly is disposed inside the first insulating film.

2. The battery cell as described in claim 1, characterized in that, The number of expansion layers is one, and the expansion layers are continuously distributed inside and / or on the surface of the second part; The expansion layer is disposed opposite to the side and bottom surfaces of the electrode assembly.

3. The battery cell as described in claim 1, characterized in that, The number of expansion layers is two or more, and the two or more expansion layers are distributed at intervals inside and / or on the surface of the second part; The expansion layer is disposed opposite to a portion of the side surface and / or a portion of the bottom surface of the electrode assembly.

4. The battery cell as described in claim 3, characterized in that, The shell has a rectangular structure, which includes multiple surfaces, including a first surface, which is the surface with the largest area among the multiple surfaces. One of the expansion layers is disposed opposite to the first surface.

5. The battery cell as described in claim 4, characterized in that, The number of the first surfaces is two, and the two first surfaces are arranged opposite to each other; The two expansion layers and the two first surfaces are respectively disposed opposite to each other.

6. The battery cell according to any one of claims 1 to 5, characterized in that, The expansion layer includes one of the following: oriented polystyrene layer, biaxially oriented polypropylene layer, biaxially oriented nylon layer, and biaxially oriented polyester layer.

7. The battery cell according to any one of claims 1 to 5, characterized in that, The substrate layer includes one of a polyethylene terephthalate layer and a polypropylene layer.

8. The battery cell according to any one of claims 1 to 5, characterized in that, The battery cell also includes a top cover assembly; The first part forms a rectangular cylindrical structure, which is inserted into the top cover assembly.

9. The battery cell as described in claim 8, characterized in that, The top cover assembly includes a lower plastic layer; The lower plastic portion is connected to the rectangular cylindrical structure by hot-melt connection.

10. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1 to 9.

11. An electrical appliance, characterized in that, Includes a battery cell as described in any one of claims 1 to 9, the battery cell being used to supply power to the electrical device.

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