Packaging film, battery monomer, battery and electric equipment

Abstract

The embodiment of the utility model provides a packaging film, a battery monomer, a battery and electric equipment. The packaging film is used for wrapping an electrode assembly. The packaging film comprises a supporting film layer and a breathable film layer which are arranged in a stacked mode. And the breathable film layer is used for wrapping the electrolyte. The supporting film layer is connected with the electrode assembly and used for supporting the breathable film layer, and a plurality of liquid storage holes are formed in the supporting film layer. The packaging film provided by the embodiment of the utility model is used for wrapping the electrode assembly and protecting the electrode assembly from being scratched and damaged, and the breathable film layer of the packaging film is relatively high in breathability and relatively low in water permeability, so that gas generated in the use process of the battery can permeate through the breathable film layer. Besides, in the electrolyte injection process, the gas-permeable film layer can prolong the retention time of the electrolyte in the packaging film, so that the electrolyte fully infiltrates the electrode assembly as much as possible, and the electrolyte injection efficiency and the infiltration effect are improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to packaging films, battery cells, batteries and electrical equipment. Background Art

[0002] This section is intended to provide a background or context for the embodiments of the present application. No description herein is admitted to be prior art by virtue of its inclusion in this section.

[0003] During the preparation of the battery cell, electrochemical corrosion is prone to occur. In addition, since the electrolyte needs to be injected during the preparation of the battery cell, the electrolyte easily flows out from the pores at the bottom of the traditional Mylar film, so the electrolyte cannot be retained for a long time, resulting in a longer infiltration time, which in turn makes the injection efficiency and infiltration effect poor. Utility Model Content

[0004] In view of this, the embodiments of the present application hope to provide a packaging film, a battery cell, a battery and an electrical device that can improve the liquid injection efficiency and the wetting effect.

[0005] To achieve the above-mentioned purpose, a first aspect of an embodiment of the present application provides a packaging film, the packaging film is used to wrap an electrode assembly, and the packaging film includes a supporting film layer and a breathable film layer stacked;

[0006] The breathable membrane layer is used to encapsulate the electrolyte;

[0007] The supporting membrane layer is connected to the electrode assembly and is used to support the breathable membrane layer, and a plurality of liquid storage holes are arranged on the supporting membrane layer.

[0008] The packaging film provided in the embodiment of the present application includes a supporting film layer and a breathable film layer that are stacked. The packaging film is used to wrap the electrode assembly to protect the electrode assembly from being scratched and damaged, and can be connected to the electrode assembly through the supporting film layer, and can be used to support the breathable film layer. By providing a breathable film layer, and providing a plurality of liquid storage holes on the supporting film layer, the gas generated by the battery during use can be emptied through the breathable film layer and the liquid storage holes. The breathable film layer is used to wrap the electrolyte, that is, the breathable film layer has a large air permeability and a low water permeability. In addition, during the injection of the electrolyte, the breathable film layer can prolong the retention time of the electrolyte in the packaging film, allowing the electrolyte to fully infiltrate the electrode assembly as much as possible, thereby improving the injection efficiency and the infiltration effect.

[0009] In some embodiments, at least one support film layer is disposed between the breathable film layer and the electrode assembly.

[0010] In this way, during the electrolyte injection process, as the electrolyte flows down, part of the electrolyte can be stored in the liquid storage holes of the support film layer, so that the electrode assembly is wetted from multiple directions, improving the injection efficiency and the wettability. In addition, when the electrode assembly needs to be replenished with electrolyte, the electrolyte in the liquid storage hole can be replenished in time.

[0011] In some embodiments, the packaging film includes at least two supporting film layers, and the breathable film layer is sandwiched between the at least two supporting film layers.

[0012] In this way, the supporting film layer can better clamp the breathable film layer in the middle of the supporting film layer to better support and protect the breathable film layer. At the same time, it is also beneficial to improve the overall structural strength of the packaging film and improve the connection stability between the packaging film and the electrode assembly.

[0013] In some embodiments, the packaging film includes two layers of support film layers, each of which includes an assembly area and a connection area located on the peripheral side of the assembly area. The two layers of support film layers are connected by the connection area, and the breathable film layer is sandwiched between the assembly areas of the two layers of support film layers.

[0014] That is to say, by setting an assembly area and a connecting area located on the peripheral side of the assembly area, by stacking the breathable film layer between two supporting film layers, and connecting the connecting areas of the two supporting film layers, the breathable film layer is sandwiched between the assembly areas of the two supporting film layers to form a packaging film.

[0015] In some embodiments, the diameter of the liquid storage hole is D, wherein 5 mm ≤ D ≤ 20 mm.

[0016] By setting the aperture of the liquid storage hole to 5mm≤D≤20mm, it is beneficial for the gas generated by the battery during use to be emptied through the breathable membrane layer and the liquid storage hole, and when the electrolyte flows down, part of the electrolyte can be stored in the liquid storage hole of the support membrane layer, so that the electrode assembly is infiltrated from multiple directions, improving the injection efficiency and infiltration effect. In addition, when the electrode assembly needs to be supplemented with electrolyte, the electrolyte in the liquid storage hole can be supplemented in time.

[0017] In some embodiments, the diameter of the liquid storage hole is D, wherein 8 mm ≤ D ≤ 16 mm.

[0018] In some embodiments, the thickness of the support film layer is X, wherein 0.2 mm≤X≤3 mm.

[0019] By setting the thickness of the support film layer to 0.2mm≤X≤3mm, the support film layer can have a certain strength and be connected to the electrode assembly through the support film layer, and it is beneficial to wrap the electrode assembly after being stacked with the breathable film layer.

[0020] In some embodiments, the breathable membrane layer has a thickness of Y, wherein 3 μm≤Y≤100 μm.

[0021] By setting the thickness of the breathable film layer to 3μm≤Y≤100μm, the breathable film layer can have greater air permeability and lower water permeability, so that the gas generated by the battery during use can pass through the breathable film layer. In addition, during the injection of electrolyte, the breathable film layer can prolong the retention time of the electrolyte in the packaging film, allowing the electrolyte to fully infiltrate the electrode assembly as much as possible, thereby improving the injection efficiency and the infiltration effect.

[0022] In some embodiments, the thickness of the support film layer is X, wherein 0.3 mm≤X≤1.5 mm.

[0023] In some embodiments, the breathable membrane layer has a thickness of Y, wherein 5 μm≤Y≤20 μm.

[0024] In some embodiments, the material of the support film layer includes one of polypropylene, polyethylene, ethylene-propylene copolymer or ethylene homopolymer.

[0025] In some embodiments, the material of the breathable membrane layer includes one of polypropylene, polyethylene, ethylene-propylene copolymer or ethylene homopolymer.

[0026] Taking the material of the breathable film layer including polyethylene as an example, the polyethylene film formed by polyethylene has low water permeability, but high air permeability, which is suitable for the gas generated by the battery during use to be discharged through the breathable film layer, and can prolong the retention time of the electrolyte in the packaging film, allowing the electrolyte to fully infiltrate the electrode assembly as much as possible, thereby improving the injection efficiency and the infiltration effect.

[0027] A second aspect of an embodiment of the present application provides a battery cell, including:

[0028] An electrode assembly, comprising a first pole piece, a second pole piece and a separation film, wherein the separation film is used to separate the first pole piece from the second pole piece;

[0029] The packaging film mentioned above is wrapped around the outside of the electrode assembly.

[0030] The packaging film of the battery cell provided in the embodiment of the present application includes a supporting film layer and a breathable film layer which are stacked. The packaging film is used to wrap the electrode assembly to protect the electrode assembly from being scratched and damaged, and can be connected to the electrode assembly through the supporting film layer, and can be used to support the breathable film layer. By providing a breathable film layer, and providing a plurality of liquid storage holes on the supporting film layer, the gas generated by the battery during use can be emptied through the breathable film layer and the liquid storage holes. The breathable film layer is used to wrap the electrolyte, that is, the breathable film layer has a large air permeability and a low water permeability, so that the gas generated by the battery during use can pass through the breathable film layer. In addition, during the injection of the electrolyte, the breathable film layer can prolong the retention time of the electrolyte in the packaging film, so that the electrolyte can fully infiltrate the electrode assembly as much as possible, thereby improving the injection efficiency and the infiltration effect.

[0031] A third aspect of an embodiment of the present application provides a battery, comprising at least one battery cell as described above.

[0032] The packaging film of the battery provided in the embodiment of the present application comprises a supporting film layer and a breathable film layer which are stacked. The packaging film is used to wrap the electrode assembly to protect the electrode assembly from being scratched and damaged, and can be connected to the electrode assembly through the supporting film layer, and can be used to support the breathable film layer. By providing a breathable film layer, and providing a plurality of liquid storage holes on the supporting film layer, the gas generated by the battery during use can be emptied through the breathable film layer and the liquid storage holes. The breathable film layer is used to wrap the electrolyte, that is, the breathable film layer has a large air permeability and a low water permeability, so that the gas generated by the battery during use can pass through the breathable film layer. In addition, during the injection of the electrolyte, the breathable film layer can prolong the retention time of the electrolyte in the packaging film, so that the electrolyte can fully infiltrate the electrode assembly as much as possible, thereby improving the injection efficiency and the infiltration effect.

[0033] A fourth aspect of an embodiment of the present application provides an electrical device, comprising the battery described above, wherein the battery is used to provide electrical energy.

[0034] The packaging film of the battery of the electric device provided in the embodiment of the present application comprises a supporting film layer and a breathable film layer arranged in layers. The packaging film is used to wrap the electrode assembly to protect the electrode assembly from being scratched and damaged, and can be connected to the electrode assembly through the supporting film layer, and can be used to support the breathable film layer. By providing a breathable film layer, and providing a plurality of liquid storage holes on the supporting film layer, the gas generated by the battery during use can be emptied through the breathable film layer and the liquid storage holes. The breathable film layer is used to wrap the electrolyte, that is, the breathable film layer has a large air permeability and a low water permeability, so that the gas generated by the battery during use can pass through the breathable film layer. In addition, during the injection of the electrolyte, the breathable film layer can prolong the retention time of the electrolyte in the packaging film, so that the electrolyte can fully infiltrate the electrode assembly as much as possible, thereby improving the injection efficiency and the infiltration effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A schematic diagram of the structure of a vehicle provided in one embodiment of the present application;

[0036] Figure 2 A three-dimensional exploded schematic diagram of a battery provided in one embodiment of the present application;

[0037] Figure 3 A three-dimensional exploded schematic diagram of a packaging film and an electrode assembly provided in one embodiment of the present application;

[0038] Figure 4 A schematic diagram of the structure of a packaging film provided in one embodiment of the present application;

[0039] Figure 5 A schematic diagram of the structure of a support membrane layer provided in one embodiment of the present application;

[0040] Figure 6 A partial schematic diagram of a packaging film provided in one embodiment of the present application;

[0041] Figure 7 A schematic diagram of the structure of a packaging film provided in one embodiment of the present application at the connection of the supporting film layer.

[0042] Description of Reference Numerals

[0043] 1. Packaging film; 11. Breathable film layer; 12. Support film layer; 12a. Liquid storage hole; 12b. Assembly area; 12c. Connection area; 2. Electrode assembly; 10. Battery cell; 20. Case; 100. Battery; 200. Controller; 300. Motor; 1000. Vehicle. DETAILED DESCRIPTION

[0044] It should be noted that, in the absence of conflict, the embodiments and technical features in the embodiments of the present application can be combined with each other, and the detailed description in the specific implementation method should be understood as an explanation of the purpose of the present application and should not be regarded as an improper limitation on the present application.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in this application are intended to cover non-exclusive inclusions.

[0046] In the description of the embodiments of the present application, the technical terms "first", "second", "third", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0047] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0048] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0049] In the description of the embodiments of the present application, the orientation or position relationship indicated by technical terms such as "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "circumferential", "height direction", "first direction", and "second direction" are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed, operated or used in a specific orientation. Therefore, they should not be understood as limitations on the embodiments of the present application.

[0050] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0051] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, the technical term "contact" should be understood in a broad sense, and may be direct contact or contact through an intermediate medium layer. It may be contact with essentially no interaction force between the two contacting parties, or it may be contact with interaction force between the two contacting parties.

[0052] With the development of clean energy, more and more devices use electric energy as driving energy, and then power batteries that can store more electric energy and can be charged and discharged repeatedly are developing rapidly, such as lithium-ion batteries. Among them, power batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as aerospace and other fields.

[0053] With the country's vigorous promotion of new energy vehicles, new energy vehicles have ushered in a great opportunity for development. The safety and stability of automobiles have always been people's greatest concern. Therefore, improving the safety of new energy vehicles will be one of the important factors that determine whether new energy vehicles can be quickly popularized. Battery modules are the main components of the battery pack of new energy vehicles. Improving the safety of battery modules is an important way to improve the safety of new energy vehicles.

[0054] In the present application, the battery cell may include a lithium-ion secondary battery, a lithium-ion primary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery or a magnesium-ion battery, etc., which is not limited in the embodiments of the present application. The battery cell may be cylindrical, rectangular or in other shapes, etc., which is not limited in the embodiments of the present application.

[0055] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in the present application may include a battery module or a battery pack. The battery generally includes a box for encapsulating one or more battery cells. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.

[0056] The battery cell includes an electrode assembly and an electrolyte. The electrode assembly is composed of a positive electrode sheet, a negative electrode sheet and a separator. The battery cell mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet includes a positive electrode collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode collector. The positive electrode collector not coated with the positive electrode active material layer protrudes from the positive electrode collector coated with the positive electrode active material layer. The positive electrode collector not coated with the positive electrode active material layer serves as the positive electrode tab. Taking lithium-ion batteries as an example, the material of the positive electrode collector can be aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc. The negative electrode sheet includes a negative electrode collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode collector. The negative electrode collector not coated with the negative electrode active material layer protrudes from the negative electrode collector coated with the negative electrode active material layer. The negative electrode collector not coated with the negative electrode active material layer serves as the negative electrode tab. The negative electrode current collector may be made of copper, and the negative electrode active material may be carbon or silicon. In order to ensure that a large current can pass without melting, the positive electrode tabs are multiple and stacked together, and the negative electrode tabs are multiple and stacked together. The material of the separator may be PP (polypropylene) or PE (polyethylene).

[0057] The battery cell also includes a packaging film and a shell. The packaging film is coated on the outside of the electrode assembly, and the shell encapsulates the electrode assembly coated with the packaging film to form a battery cell. The packaging film can be a Mylar film, and the shell can be an aluminum shell. After the electrode assembly is wound and formed, the Mylar film and the shell are encapsulated through the Mylar wrapping process and the shelling process. Among them, the Mylar film plays a role in sealing and protecting the electrode assembly, and the Mylar film can effectively insulate the electrode assembly and the shell from each other to avoid internal short circuits in the battery cell. The shell plays a protective role.

[0058] During the preparation of the battery, electrolyte needs to be injected, and the electrolyte easily flows out from the pores at the bottom of the traditional Mylar film, so the electrolyte cannot be retained for a long time, resulting in a longer infiltration time, which in turn makes the injection efficiency and infiltration effect poor.

[0059] In view of this, in order to improve the injection efficiency and the wetting effect, the present application provides a packaging film, which is used to wrap the electrode assembly. The packaging film includes a supporting film layer and a breathable film layer stacked. The breathable film layer is used to wrap the electrolyte. The supporting film layer is connected to the electrode assembly and is used to support the breathable film layer, and a plurality of liquid storage holes are provided on the supporting film layer.

[0060] The packaging film provided in the embodiment of the present application includes a supporting film layer and a breathable film layer which are stacked. The packaging film is used to wrap the electrode assembly to protect the electrode assembly from being scratched and damaged, and can be connected to the electrode assembly through the supporting film layer, and can be used to support the breathable film layer. By providing a breathable film layer, and providing a plurality of liquid storage holes on the supporting film layer, the gas generated by the battery during use can be emptied through the breathable film layer and the liquid storage holes. The breathable film layer is used to wrap the electrolyte, that is, the breathable film layer has a large air permeability and a low water permeability, so that the gas generated by the battery during use can pass through the breathable film layer. In addition, during the injection of the electrolyte, the breathable film layer can prolong the retention time of the electrolyte in the packaging film, so that the electrolyte can fully infiltrate the electrode assembly as much as possible, thereby improving the injection efficiency and the infiltration effect.

[0061] The technical solutions described in the embodiments of the present application are applicable to battery cells, batteries, and electrical equipment using batteries.

[0062] Electrical equipment may be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, electric tools, and the like. Vehicles may be fuel vehicles, gas vehicles, or new energy vehicles, and new energy vehicles may be pure electric vehicles, hybrid vehicles, or extended-range vehicles, and the like; spacecraft include airplanes, rockets, space shuttles, and spacecraft, and the like; electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and the like; electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, and the like. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical equipment.

[0063] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0064] Figure 1 Schematic diagram of the structure of a vehicle according to some embodiments of the present application. A controller, a motor and a battery may be arranged inside the vehicle, and the controller is used to control the battery to power the motor. For example, a battery may be arranged at the bottom, front or rear of the vehicle. The battery may be used to power the vehicle, for example, the battery may be used as an operating power source for the vehicle, for the circuit system of the vehicle, for example, for the working power requirements during the start-up, navigation and operation of the vehicle. In another embodiment of the present application, the battery may not only be used as an operating power source for the vehicle, but also as a driving power source for the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0065] The battery includes at least one battery cell, which can be one or more.

[0066] See also Figure 2 , multiple battery cells can be connected in series, in parallel or in a mixed connection. A mixed connection means that multiple battery cells are connected in series and in parallel. Multiple battery cells can be directly connected in series, in parallel or in a mixed connection, and then the whole formed by multiple battery cells is accommodated in a box; of course, the battery can also be a battery module formed by connecting multiple battery cells in series, in parallel or in a mixed connection, and then the multiple battery modules are connected in series, in parallel or in a mixed connection to form a whole, and accommodated in a box. The battery may also include other structures. For example, the battery may also include a confluence component for achieving electrical connection between multiple battery cells. Each battery cell may be a secondary battery or a primary battery; it may also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited thereto. The battery cell may be cylindrical, flat, rectangular or in other shapes.

[0067] The battery cell includes an electrode assembly and a packaging film. The electrode assembly is a wound structure, and the electrode assembly includes a first pole piece, a second pole piece and a separator, and the separator is used to separate the first pole piece from the second pole piece. The packaging film is wrapped around the outside of the electrode assembly.

[0068] The packaging film 1 provided in the embodiment of the present application is used to wrap the electrode assembly 2. Figures 3 to 7 The packaging film 1 includes a stacked support film layer 12 and a breathable film layer 11. The breathable film layer 11 is used to wrap the electrolyte. The support film layer 12 is connected to the electrode assembly 2 and is used to support the breathable film layer 11. The support film layer 12 is provided with a plurality of liquid storage holes 12a.

[0069] The packaging film 1 includes a supporting film layer 12 and a breathable film layer 11 which are stacked together, which means that the supporting film layer 12 and the breathable film layer 11 are stacked together to form the packaging film 1 together.

[0070] It is understandable that the breathable film layer 11 can be used for ventilation, so that the gas generated by the battery 100 during use can be discharged through the breathable film layer 11, that is, the breathable film layer 11 needs to have a certain air permeability, for example, the breathable film layer 11 is a thin film layer with micropores formed inside.

[0071] It is understandable that, during the process of injecting the electrolyte, the electrolyte needs to be retained in the packaging film 1 for a certain period of time, that is, the breathable film layer 11 can be used to wrap the electrolyte, that is, the water permeability of the breathable film layer 11 is low. Therefore, the breathable film layer 11 can prolong the retention time of the electrolyte in the packaging film 1, allowing the electrolyte to fully infiltrate the electrode assembly 2 as much as possible, thereby improving the injection efficiency and the infiltration effect.

[0072] The supporting film layer 12 is provided with a plurality of liquid storage holes 12 a , and the gas generated by the battery 100 during use can be discharged through the breathable film layer 11 and the liquid storage holes 12 a .

[0073] The packaging film 1 provided in the embodiment of the present application includes a supporting film layer 12 and a breathable film layer 11 which are stacked. The packaging film 1 is used to wrap the electrode assembly, protect the electrode assembly 2 from being scratched and damaged, and can be connected to the electrode assembly 2 through the supporting film layer 12, and can be used to support the breathable film layer 11. By providing the breathable film layer 11, and providing a plurality of liquid storage holes 12a on the supporting film layer 12, the gas generated by the battery 100 during use can be emptied through the breathable film layer 11 and the liquid storage holes 12a. The breathable film layer 11 is used to wrap the electrolyte, that is, the breathable film layer 11 has a large air permeability and a low water permeability, so that the gas generated by the battery 100 during use can pass through the breathable film layer 11. In addition, during the injection of the electrolyte, the breathable film layer 11 can prolong the retention time of the electrolyte in the packaging film 1, so that the electrolyte can fully infiltrate the electrode assembly 2 as much as possible, thereby improving the injection efficiency and the infiltration effect.

[0074] It should be noted that there are many specific forms of stacking the support film layer 12 and the breathable film layer 11. The number of the support film layer 12 and the breathable film layer 11 is not limited here.

[0075] In some embodiments, at least one supporting film layer 12 is disposed between the breathable film layer 11 and the electrode assembly 2 .

[0076] At least one support film layer 12 is disposed between the breathable film layer 11 and the electrode assembly 2, which means that there may be one support film layer 12 or multiple support film layers 12 disposed between the breathable film layer 11 and the electrode assembly 2. Of course, a support film layer 12 may also be disposed outside the breathable film layer 11.

[0077] In this way, during the process of injecting the electrolyte, when the electrolyte flows down, part of the electrolyte can be stored in the liquid storage hole 12a of the support film layer 12, so that the electrode assembly 2 is infiltrated from multiple directions, thereby improving the injection efficiency and the infiltration effect. In addition, when the electrode assembly 2 needs to be supplemented with electrolyte, the electrolyte in the liquid storage hole 12a can be supplemented in time.

[0078] In some embodiments, see Figures 3 to 7 The packaging film 1 includes at least two supporting film layers 12. The breathable film layer 11 is sandwiched between the at least two supporting film layers 12.

[0079] That the packaging film 1 includes at least two supporting film layers 12 means that the packaging film 1 may include two supporting film layers 12 or may include multiple supporting film layers 12 .

[0080] The multi-layers described in the embodiments of the present application refer to two layers or more than two layers.

[0081] The breathable membrane layer 11 is sandwiched between at least two support membrane layers 12, which means that at least one support membrane layer 12 is located between the breathable membrane layer 11 and the electrode assembly 2 (equivalent to being located on the inner side of the breathable membrane layer 11), and at least one support membrane layer 12 is located on the outer side of the breathable membrane layer 11.

[0082] In this way, the supporting film layer 12 can better clamp the breathable film layer 11 in the middle of the supporting film layer 12 to better support and protect the breathable film layer 11. At the same time, it is also beneficial to improve the overall structural strength of the packaging film 1 and improve the connection stability between the packaging film 1 and the electrode assembly 2.

[0083] It should be noted that the specific connection method between the support film layer 12 and the breathable film layer 11 is not limited here.

[0084] In some embodiments, see Figure 6 to Figure 7 The packaging film 1 includes two supporting film layers 12. The two supporting film layers 12 each include an assembly region 12b and a connection region 12c located around the assembly region 12b. The two supporting film layers 12 are connected via the connection region 12c, and the breathable film layer 11 is sandwiched between the assembly regions 12b of the two supporting film layers 12.

[0085] The two supporting film layers 12 each include an assembly area 12b and a connection area 12c located around the assembly area 12b, the connection area 12c is used for connection, the assembly areas 12b of the two supporting film layers 12 define an assembly space, and the breathable film layer 11 is sandwiched in the assembly space.

[0086] That is to say, by setting the assembly area 12b and the connecting area 12c located on the peripheral side of the assembly area 12b, by stacking the breathable film layer 11 between two supporting film layers 12, and connecting the connecting areas 12c of the two supporting film layers 12, the breathable film layer 11 is sandwiched between the assembly areas 12b of the two supporting film layers 12 to form the packaging film 1.

[0087] The specific method of connecting the connection areas 12c of the two supporting film layers 12 is not limited here. For example, the connection areas 12c of the two supporting film layers 12 can be hot-melted by a hot-melt machine to achieve the connection between the two supporting film layers 12.

[0088] It should be noted that the specific material of the breathable film layer 11 is not limited herein. For example, in some embodiments, the material of the breathable film layer 11 includes one of polypropylene, polyethylene, ethylene-propylene copolymer or ethylene homopolymer.

[0089] Among them, ethylene homopolymer is an amorphous polymer obtained by uniform polymerization of ethylene monomer.

[0090] Polyethylene is a linear or branched crystal obtained by chain extension and side chain branching reactions of ethylene molecules.

[0091] Taking the material of the breathable film layer 11 including polyethylene as an example, the polyethylene film formed by polyethylene has low water permeability, but high air permeability, which is suitable for the gas generated by the battery 100 during use to be discharged through the breathable film layer 11, and can prolong the retention time of the electrolyte in the packaging film 1, allowing the electrolyte to fully infiltrate the electrode assembly 2 as much as possible, thereby improving the injection efficiency and the infiltration effect.

[0092] It should be noted that the specific material of the support film layer 12 is not limited herein. For example, in some embodiments, the material of the breathable film layer 11 includes one of polypropylene, polyethylene, ethylene-propylene copolymer or ethylene homopolymer.

[0093] In some embodiments, see Figure 5 The diameter of the liquid storage hole 12a is D, wherein 5mm≤D≤20mm, for example, 5mm, 6mm, 7mm, 8mm, 11mm, 12mm, 15mm, 16mm, 17mm, 18mm, 19mm or 20mm, etc.

[0094] It should be noted that the pore size of the liquid storage hole 12 a can be obtained through CCD testing at room temperature when the packaging film 1 is not wrapped around the electrode assembly 2 .

[0095] By setting the aperture of the liquid storage hole 12a to 5mm≤D≤20mm, it is beneficial for the gas generated by the battery 100 during use to be emptied through the breathable membrane layer 11 and the liquid storage hole 12a, and when the electrolyte flows down, part of the electrolyte can be stored in the liquid storage hole 12a of the support membrane layer 12, so that the electrode assembly 2 is infiltrated from multiple directions, thereby improving the injection efficiency and the infiltration effect. In addition, when the electrode assembly 2 needs to be supplemented with electrolyte, the electrolyte in the liquid storage hole 12a can be supplemented in time.

[0096] In some other embodiments, the diameter of the liquid storage hole 12a is D, wherein 8 mm ≤ D ≤ 16 mm, such as 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm or 16 mm.

[0097] In some embodiments, see Figure 6The thickness of the supporting film layer 12 is X, wherein 0.2 mm ≤ X ≤ 3 mm, for example, 0.2 mm, 0.6 mm, 0.7 mm, 0.8 mm, 1.1 mm, 1.2 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.7 mm, 2.8 mm, 2.9 mm or 3.0 mm, etc.

[0098] By setting the thickness of the support film layer 12 to 0.2mm≤X≤3mm, the support film layer 12 can have a certain strength and be connected to the electrode assembly 2 through the support film layer 12, and it is beneficial to wrap the electrode assembly 2 after being stacked with the breathable film layer 11.

[0099] In other embodiments, the thickness of the supporting film layer 12 is X, wherein 0.3 mm ≤ X ≤ 1.5 mm, for example, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm or 1.5 mm, etc.

[0100] In some embodiments, see Figure 6 The thickness of the breathable membrane layer 11 is Y, wherein 3 μm ≤ Y ≤ 100 μm, for example, 3 μm, 5 μm, 10 μm, 13 μm, 15 μm, 20 μm, 25 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 83 μm, 95 μm or 100 μm, etc.

[0101] By setting the thickness of the breathable film layer 11 to 3μm≤Y≤100μm, the breathable film layer 11 can have a larger air permeability and a lower water permeability. In addition, during the injection of the electrolyte, the breathable film layer 11 can prolong the retention time of the electrolyte in the packaging film 1, allowing the electrolyte to fully infiltrate the electrode assembly 2 as much as possible, thereby improving the injection efficiency and the infiltration effect.

[0102] In other embodiments, the thickness of the breathable membrane layer 11 is Y, wherein 5 μm ≤ Y ≤ 20 μm, for example, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm or 20 μm, etc.

[0103] It should be noted that the thickness of the support film layer and the thickness of the breathable film layer can be obtained by testing with a high-precision thickness gauge at room temperature when the packaging film is not wrapped around the electrode assembly.

[0104] In the description of the present application, the description with reference to the terms "in one embodiment", "in some embodiments", "in other embodiments", "in yet other embodiments", or "exemplary" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In the present application, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine the different embodiments or examples described in the present application and the features of the different embodiments or examples without contradiction.

[0105] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application are included in the protection scope of the present application.

Claims

1. A packaging film, characterized in that: The packaging film is used to wrap the electrode assembly, and the packaging film includes a supporting film layer and a breathable film layer stacked; The breathable membrane layer is used to wrap the electrolyte; The supporting film layer is connected to the electrode assembly and is used to support the breathable film layer, and a plurality of liquid storage holes are arranged on the supporting film layer.

2. The packaging film according to claim 1, characterized in that: At least one support film layer is arranged between the breathable film layer and the electrode assembly.

3. The packaging film according to claim 1, characterized in that: The packaging film comprises at least two supporting film layers, and the breathable film layer is sandwiched between the at least two supporting film layers.

4. The packaging film according to claim 3, characterized in that: The packaging film comprises two layers of support film layers, each of which comprises an assembly area and a connection area located on the peripheral side of the assembly area, the two layers of support film layers are connected via the connection area, and the breathable film layer is sandwiched between the assembly areas of the two layers of support film layers.

5. The packaging film according to claim 1, characterized in that: The aperture of the liquid storage hole is D, wherein 5mm≤D≤20mm.

6. The packaging film according to claim 5, characterized in that: The aperture of the liquid storage hole is D, wherein 8mm≤D≤16mm.

7. The packaging film according to claim 1, characterized in that: The thickness of the supporting film layer is X, wherein 0.2 mm ≤ X ≤ 3 mm; and / or the thickness of the breathable film layer is Y, wherein 3 μm ≤ Y ≤ 100 μm.

8. The packaging film according to claim 1, characterized in that: The thickness of the supporting film layer is X, wherein 0.3 mm ≤ X ≤ 1.5 mm; and / or the thickness of the breathable film layer is Y, wherein 5 μm ≤ Y ≤ 20 μm.

9. The packaging film according to claim 1, characterized in that: The material of the supporting film layer includes one of polypropylene, polyethylene, ethylene-propylene copolymer or ethylene homopolymer; and / or the material of the breathable film layer includes one of polypropylene, polyethylene, ethylene-propylene copolymer or ethylene homopolymer.

10. A battery cell, characterized in that: include: An electrode assembly, comprising a first pole piece, a second pole piece and a separation film, wherein the separation film is used to separate the first pole piece from the second pole piece; The packaging film according to any one of claims 1 to 9, wherein the packaging film is wrapped around the outside of the electrode assembly.

11. A battery, characterized in that: The invention comprises at least one battery cell according to claim 10.

12. An electrical equipment, characterized in that: A battery according to claim 11, wherein the battery is used to provide electrical energy.

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