WO2023240602A1

WO2023240602A1 - Separation film roll and preparation method therefor

Info

Publication number: WO2023240602A1
Application number: PCT/CN2022/099483
Authority: WO
Inventors: 李成; 徐冲; 杨建瑞
Original assignee: 宁德时代新能源科技股份有限公司
Priority date: 2022-06-17
Filing date: 2022-06-17
Publication date: 2023-12-21

Abstract

A separation film roll and a preparation method therefor. The separation film roll (2000) comprises a separation film body (231) and an early-warning portion (232), wherein the separation film body (231) has a head end (a) and a tail end (b) in a lengthwise direction (F1), and is configured to be able to wind in the lengthwise direction (F1); and the early-warning portion (232) is arranged on the separation film body (231), and is configured to be spaced apart from the tail end (b) by a first preset length (L1).

Description

Isolation film roll and preparation method thereof

Technical field

The present application relates to the field of battery technology, and in particular to isolation film rolls and preparation methods thereof.

Background technique

Energy conservation and emission reduction are the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their advantages in energy conservation and environmental protection. For electric vehicles, battery technology is an important factor related to their development. The electrode assembly (also called bare cell) is an important part of the battery. During the production process of the electrode assembly, the isolation film body needs to be provided as an important insulating component.

After the production is completed, the isolation film body is generally rolled to form an isolation film roll, and insulating connectors are provided between adjacent isolation films to connect all isolation film bodies into a whole. In the subsequent manufacturing process, it is necessary to perform a winding process on the isolation film body in the isolation film roll to finally obtain the electrode assembly.

However, during the winding process, it is easy for the separator body to break or the connectors between adjacent separator bodies to be rolled into the electrode assembly, resulting in low production quality and production efficiency of the electrode assembly.

Contents of the invention

In view of this, this application provides an isolation film roll and a preparation method thereof, which can reduce scrapping caused by broken belts or entangled connectors during the production process of electrode assemblies, and improve the production quality and production efficiency of electrode assemblies.

In a first aspect, the application provides an isolation film roll, including an isolation film body, which has a head end and a tail end along the length direction and is configured to be able to be wound along the length direction, and an early warning part located on the isolation film. The body and the warning part are configured to be spaced apart from the tail end by a first preset length.

In this application, the tail end position of the isolation membrane body is warned in advance through the early warning unit. When the early warning unit is detected, it indicates that the tail end of the isolation membrane body still has a first preset length at this time, thereby affecting the tail end of the isolation membrane body. Pre-judge the end position in advance and make corresponding adjustments to prevent the isolation membrane body from being broken due to insufficient tail end length during winding or the non-isolation membrane body structure connected to the tail end being directly wound into the inside of the electrode assembly. , ensuring the production quality and winding efficiency of the electrode assembly.

In some embodiments, the isolation film roll includes a plurality of isolation film bodies, and every two adjacent isolation film bodies are connected end to end through connecting members. By arranging connectors, multiple isolation film bodies can be wound simultaneously on one isolation film roll. At this time, through the setting of the early warning part, the specific position of the connecting piece can be known, so as to prevent the connecting piece between two adjacent isolation film bodies from being wound into the electrode assembly during the high-speed winding process of the electrode assembly, thereby forming an inconsistency. Qualified electrode components, a phenomenon that affects the production quality of electrode components.

In some embodiments, each isolation membrane body is provided with an early warning part. The early warning part is used to provide a position warning to the tail end of the isolation membrane body to prevent the isolation membrane body from being damaged during the high-speed winding process of the electrode assembly. The length of the tail end is insufficient and the belt breaks.

In some embodiments, the early warning portion is provided on the surface of the isolation membrane body, and the early warning portion extends along the length direction and/or the width direction of the isolation membrane body, so that the early warning portion has sufficient strength in the width direction and/or the length direction of the isolation membrane body. size to ensure that the warning part can be detected by the detection device.

In some embodiments, the warning part is a warning coating coated on the surface of the isolation membrane body. The early warning coating can be made of low-cost materials such as glue and pigments, and the setting method is simple and easy to be identified by the detection device.

In some embodiments, the warning coating includes a glue material made of rubber. By applying adhesive material on the surface of the isolation membrane body, an early warning part is quickly formed. In some exemplary embodiments, 5# glue made of natural rubber can be used, which has a faster setting time and higher adhesion strength.

In some embodiments, the color of the isolation film body is different from the color of the warning part. Ensure that the color of the early warning part can be clearly distinguished from the isolation membrane body, so that it can be recognized and produce an early warning effect.

In some embodiments, the connecting member includes a joint tape formed of polyethylene terephthalate to connect the head ends and tail ends of two adjacent isolation film bodies through adhesion. The splicing tape formed by it has excellent physical and mechanical properties, friction resistance, dimensional stability and excellent electrical insulation in a wide temperature range. The long-term use temperature can reach 120°C, thus insulatingly isolating adjacent ones. The membrane body is connected.

In a second aspect, this application provides a method for preparing an isolation film roll, including the following steps:

An isolation membrane body is provided, and the isolation membrane body is formed with a head end and a tail end along its length;

An early warning part is provided on the isolation membrane body, and the early warning part is configured to be spaced apart from the tail end by a first preset length;

The isolation film body is rolled along the length direction to form an isolation film roll.

In this way, the rear end position of the isolation membrane body is warned in advance through the early warning part.

In some embodiments, providing the isolation membrane body specifically includes: providing multiple isolation membrane bodies, and every two isolation membrane bodies are connected end to end. Multiple isolation film bodies can be wound simultaneously on one isolation film roll. It realizes continuous winding and continuous peeling of the isolation film body, thereby improving production efficiency.

In some embodiments, arranging the early warning part on the isolation membrane body specifically includes: arranging one early warning part on each isolation membrane body. The early warning part is used to provide position warning for the tail end of the isolation membrane body to avoid the disconnection of the isolation membrane body due to insufficient length at the tail end during the high-speed winding process of the electrode assembly.

In some embodiments, connecting two isolation membrane bodies end to end further includes: connecting the head end and the tail end of each two isolation membrane bodies through a connector.

By arranging connectors, multiple isolation film bodies can be wound simultaneously on one isolation film roll. At this time, through the setting of the early warning part, the specific position of the connecting piece can be known, so as to prevent the connecting piece between two adjacent isolation film bodies from being wound into the electrode assembly during the high-speed winding process of the electrode assembly, thereby forming an inconsistency. Qualified electrode components, a phenomenon that affects the production quality of electrode components.

In some embodiments, connecting the head ends and tail ends of each two isolation membrane bodies through connectors specifically includes: providing polyethylene terephthalate to form a splice tape to adhere the head ends of each two isolation membrane bodies. and tail end.

When multiple isolation film bodies need to be wound into an isolation film roll, a splicing tape is pasted at the connection position of each two isolation film bodies, thereby connecting the multiple isolation film bodies and rolling them to form an isolation film roll. When it is necessary to peel off the isolation film body from the isolation film roll, the warning part will warn the position of the splicing tape in advance, prompting the downstream device to cut the tail end of the isolation film body to prevent the splicing tape from being wound with the isolation film body. to the inside of the electrode assembly, thereby affecting the production quality of the electrode assembly.

In some embodiments, arranging the early warning portion on the isolation membrane body also includes: coating an early warning coating on the surface of the isolation membrane body to form an early warning portion. The early warning coating can be low-cost materials such as glue and pigments, and the installation method is simple. , to facilitate identification by the detected device.

In some embodiments, applying the early warning coating on the surface of the isolation membrane body further includes: extending the early warning coating along the length direction of the isolation membrane body, and extending the application of the early warning coating along the width direction of the isolation membrane body.

The early warning part is made to have sufficient size in the width direction and/or length direction of the isolation membrane body to ensure that the early warning part can be detected by an external detection device.

In some embodiments, applying an early warning coating on the surface of the isolation membrane body further includes: applying an early warning coating with a second preset length along the length direction of the isolation membrane body, and the second preset length ranges from 10 mm to 50 mm. .

In this way, controlling the second preset length range to 10mm-50mm can provide a sufficient detection distance when the early warning part passes the external detection device, so as to ensure that the early warning part can be effectively detected.

In some embodiments, extending the early warning coating along the width direction of the isolation membrane body further includes: applying the early warning coating along the width direction of the isolation membrane body to between the two side edges of the early warning portion and the two side edges of the isolation membrane body. The distance range is 5mm-30mm.

In the range of 5mm-30mm, it can be ensured that the early warning part can be effectively detected by external detection devices, and at the same time, the mutual influence between the early warning part and the tab can be avoided.

In some embodiments, before applying the early warning coating on the surface of the isolation membrane body to form the early warning part, the method further includes: providing an early warning coating, the early warning coating including a glue material made of rubber, by applying the adhesive material on the surface of the isolation membrane body. Apply glue to quickly form an early warning part.

In some embodiments, the color of the isolation film body is different from the color of the early warning part to ensure that the color of the early warning part can be clearly distinguished from the isolation film body, thereby being recognized and generating an early warning effect.

The details of one or more embodiments of the application are set forth in the accompanying drawings and the description below. Other features, objects and advantages of the application will become apparent from the description, drawings and claims.

Description of the drawings

In order to explain the technical solutions of the embodiments of the present application more clearly, the drawings required to be used in the embodiments of the present application will be briefly introduced below. Obviously, the following descriptions are only some embodiments of the present application. For ordinary people in the art, For technicians, other drawings can also be obtained based on the drawings without any creative work:

Figure 1 is a schematic structural diagram of a vehicle provided by some embodiments of the present application;

Figure 2 is a schematic structural diagram of a battery provided by some embodiments of the present application;

Figure 3 is an exploded schematic diagram of a battery cell in an embodiment of the present application;

Figure 4 is a schematic three-dimensional structural diagram of an isolation film roll in an embodiment of the present application;

Figure 5 is a schematic three-dimensional structural diagram of an isolation film roll in an embodiment of the present application;

Figure 6 is a schematic plan view of the isolation film body and the warning part in the isolation film roll in one embodiment of the present application;

Figure 7 is a schematic plan view of the isolation film body and the warning part in the isolation film roll in one embodiment of the present application;

Figure 8 is a schematic plan view of the isolation film body and the warning part in the isolation film roll in one embodiment of the present application;

Figure 9 is a schematic plan view of the isolation film body and the warning part in the isolation film roll in one embodiment of the present application;

Figure 10 is a schematic plan view of the isolation film body and the warning part in the isolation film roll in one embodiment of the present application;

Figure 11 is a schematic flow chart of a method for preparing an isolation film roll in an embodiment of the present application;

Figure 12 is a schematic flow chart of a method for preparing an isolation film roll in an embodiment of the present application;

Figure 13 is a schematic flow chart of a method for preparing an isolation film roll in an embodiment of the present application;

Figure 14 is a schematic flow chart of a method for preparing an isolation film roll in an embodiment of the present application;

Figure 15 is a schematic flow chart of a method for preparing an isolation film roll in an embodiment of the present application;

Figure 16 is a schematic flow chart of a method for preparing an isolation film roll in an embodiment of the present application;

Figure 17 is a schematic flow chart of a method for preparing an isolation film roll in an embodiment of the present application;

Figure 18 is a schematic flow chart of a method for preparing an isolation film roll in an embodiment of the present application.

1000. Vehicle; 100. Battery; 200. Controller; 300. Motor; 10. Box; 11. First part; 12. Second part; 20. Battery cell; 21. End cover; 211. Electrode terminal; 22 , shell; 23, electrode assembly; 2000, isolation membrane roll; 231, isolation membrane body; a, head end; b, tail end; 232, early warning part; 30, connection piece 30; 40, support piece; L1, No. One preset length; L2, the second preset length; F1, length direction (winding direction); F2, width direction.

Detailed ways

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

Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the technical field belonging to this application; the terms used herein are for the purpose of describing specific embodiments only and are not intended to be used in Limitation of this application; the terms "including" and "having" and any variations thereof in the description and claims of this application and the above description of the drawings are intended to cover non-exclusive inclusion.

In the description of the embodiments of this application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying the relative importance or implicitly indicating the quantity or specificity of the indicated technical features. Sequence or priority relationship. In the description of the embodiments of this application, "plurality" means two or more, unless otherwise explicitly and specifically limited.

Reference herein to "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The appearances of this phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those skilled in the art understand, both explicitly and implicitly, that the embodiments described herein may be combined with other embodiments.

In the description of the embodiments of this application, the term "and/or" is only an association relationship describing associated objects, indicating that there can be three relationships, such as A and/or B, which can mean: A exists alone, and A exists simultaneously and B, there are three cases of B alone. In some embodiments, the character "/" in this article generally indicates that the related objects are in an "or" relationship.

In the description of the embodiments of this application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to two or more groups (including two groups), and "multiple pieces" refers to It is more than two pieces (including two pieces).

In the description of the embodiments of this application, the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right" and "vertical" The orientation or positional relationships indicated by "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on those shown in the accompanying drawings. The orientation or positional relationship is only for the convenience of describing the embodiments of the present application and simplifying the description. It does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the implementation of the present application. Example limitations.

In the description of the embodiments of this application, unless otherwise clearly stated and limited, technical terms such as "installation", "connection", "connection" and "fixing" should be understood in a broad sense. For example, it can be a fixed connection or a removable connection. It can be disassembled and connected, or integrated; it can also be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two elements or an interaction between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of this application can be understood according to specific circumstances.

At present, judging from the development of the market situation, the application of battery packs is becoming more and more extensive. Battery packs are not only used in energy storage power systems such as hydraulic, thermal, wind and solar power stations, but are also widely used in electric vehicles such as electric bicycles, electric motorcycles and electric cars, as well as in many fields such as military equipment and aerospace. . As the application fields of battery packs continue to expand, their market demand is also expanding.

The applicant noticed that during the manufacturing process of the electrode assembly of the battery, the isolation film body, which is an important insulating component, is generally rolled into an isolation film roll for storage after the production is completed to facilitate use in subsequent processes. Rolled isolation film rolls are generally wound with at least one isolation film body. When multiple isolation film bodies are wound end to end, insulating connectors are provided between adjacent isolation film bodies to connect all isolation film bodies. Connected into a whole, in the subsequent production process of the electrode assembly, the isolation film is gradually peeled off from the isolation film roll, and the anode electrode piece and the cathode electrode piece are stacked for the winding process to obtain the final electrode assembly.

However, during the process of peeling off the isolation film body from the isolation film roll and winding it up, it is impossible to determine the position of the tail end of each isolation film body, that is, the position of the connecting piece between two adjacent isolation film bodies cannot be determined or The remaining winding length of the isolation film body cannot be judged, which leads to the failure of the insulating connector being rolled into the internal structure of the electrode assembly during the winding process, or the end length of the isolation film body is insufficient during winding and the tape is broken. situation, thereby affecting the production quality and winding efficiency of the electrode assembly.

In order to improve the production quality of the electrode assembly, the applicant found that a corresponding structure can be set up to detect the position of the tail end of the isolation membrane to provide an early warning of the position of the end of the isolation membrane or the connector.

Based on the above considerations, in order to avoid the influence of the tail end position of the isolation film winding on the production quality and winding efficiency of the electrode assembly during the winding process of the isolation film, the applicant has designed a isolation film roll after in-depth research. The isolation film roll includes an isolation film body and an early warning part located on the isolation film body. The isolation film body has a head end and a tail end along the length direction, and is wound along the length direction to form an isolation film roll. The early warning part is configured to be in contact with the location. The tail ends of the isolation membrane body are spaced apart by a first preset length. At this time, the early warning part is used to warn the tail end position of the isolation membrane body in advance. When the early warning part is detected, it indicates that the tail end of the isolation membrane body still has the first preset length at this time, so as to make early predictions and make corresponding adjustments. Adjustment to avoid insufficient winding length at the tail end or the connection piece at the tail end being directly wound into the inside of the electrode assembly, so that the production quality and winding efficiency of the electrode assembly can be guaranteed.

The batteries disclosed in the embodiments of the present application can be used in, but are not limited to, electrical devices such as vehicles, ships, or aircrafts. The power supply system of the electrical device can be composed of the battery disclosed in this application. The installation body involved in this application is a structure used to install batteries in electrical devices.

Embodiments of the present application provide an electrical device that uses a battery as a power source. The electrical device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery car, an electric vehicle, a ship, a spacecraft, etc. Among them, electric toys can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, spaceships, etc.

For the convenience of explanation in the following embodiments, an electric device 1000 according to an embodiment of the present application is used as an example.

Please refer to FIG. 1 , which is a schematic structural diagram of a vehicle 1000 provided by some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. The battery 100 is disposed inside the vehicle 1000 , and the battery 100 may be disposed at the bottom, head, or tail of the vehicle 1000 . The battery 100 may be used to power the vehicle 1000 , for example, the battery 100 may serve as an operating power source for the vehicle 1000 . The vehicle 1000 may also include a controller 200 and a motor 300 . The controller 200 is used to control the battery 100 to provide power to the motor 300 , for example, for starting, navigating and driving the vehicle 1000 .

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

Please refer to FIG. 2 , which is an exploded view of the battery 100 provided by some embodiments of the present application. The battery 100 includes a case 10 and battery cells 20 , and the battery cells 20 are accommodated in the case 10 . Among them, the box 10 is used to provide a storage space for the battery cells 20, and the box 10 can adopt a variety of structures. In some embodiments, the box 10 may include a first part 11 and a second part 12 , the first part 11 and the second part 12 cover each other, and the first part 11 and the second part 12 jointly define a space for accommodating the battery cells 20 of accommodation space. The second part 12 may be a hollow structure with one end open, and the first part 11 may be a plate-like structure. The first part 11 covers the open side of the second part 12 so that the first part 11 and the second part 12 jointly define a receiving space. ; The first part 11 and the second part 12 may also be hollow structures with one side open, and the open side of the first part 11 is covered with the open side of the second part 12. Of course, the box 10 formed by the first part 11 and the second part 12 can be in various shapes, such as cylinder, rectangular parallelepiped, etc.

In the battery 100, there may be a plurality of battery cells 20, and the plurality of battery cells 20 may be connected in series, in parallel, or in mixed connection. Mixed connection means that the plurality of battery cells 20 are connected in series and in parallel. The plurality of battery cells 20 can be directly connected in series or in parallel or mixed together, and then the whole composed of the plurality of battery cells 20 can be accommodated in the box 10 ; of course, the battery 100 can also be a plurality of battery cells 20 First, the battery modules are connected in series, parallel, or mixed to form a battery module, and then multiple battery modules are connected in series, parallel, or mixed to form a whole, and are accommodated in the box 10 . The battery 100 may also include other structures. For example, the battery 100 may further include a bus component for realizing electrical connections between multiple battery cells 20 .

Each battery cell 20 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 20 may be in the shape of a cylinder, a flat body, a rectangular parallelepiped or other shapes.

Please refer to FIG. 3 , which is an exploded structural diagram of a battery cell 20 provided in some embodiments of the present application. The battery cell 20 refers to the smallest unit that constitutes the battery. As shown in FIG. 3 , the battery cell 20 includes an end cover 21 , a case 22 , an electrode assembly 23 and other functional components.

The end cap 21 refers to a component that covers the opening of the case 22 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 21 can be adapted to the shape of the housing 22 to fit the housing 22 . In some embodiments, the end cap 21 can be made of a material with a certain hardness and strength (such as aluminum alloy). In this way, the end cap 21 is less likely to deform when subjected to extrusion and collision, so that the battery cell 20 can have better properties. With high structural strength, safety performance can also be improved. Functional components such as electrode terminals 211 may be provided on the end cap 21 . The electrode terminals may be used to electrically connect with the electrode assembly 23 for outputting or inputting electrical energy of the battery cell 20 . In some embodiments, the end cap 21 may also be provided with a pressure relief structure 24 for releasing the internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold. The end cap 21 can also be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which are not particularly limited in the embodiment of the present application. In some embodiments, an insulating member may also be provided inside the end cover 21 , and the insulating member may be used to isolate the electrical connection components in the housing 22 from the end cover 21 to reduce the risk of short circuit. For example, the insulating member may be plastic, rubber, etc.

The housing 22 is a component used to cooperate with the end cover 21 to form an internal environment of the battery cell 20 , wherein the formed internal environment can be used to accommodate the electrode assembly 23 , electrolyte, and other components. The housing 22 and the end cover 21 may be independent components, and an opening may be provided on the housing 22. The end cover 21 covers the opening at the opening to form the internal environment of the battery cell 20. Without limitation, the end cover 21 and the housing 22 can also be integrated. Specifically, the end cover 21 and the housing 22 can form a common connection surface before other components are put into the housing. When it is necessary to encapsulate the inside of the housing 22 When, the end cover 21 is closed with the housing 22 again. The housing 22 can be of various shapes and sizes, such as rectangular parallelepiped, cylinder, hexagonal prism, etc. Specifically, the shape of the housing 22 can be determined according to the specific shape and size of the electrode assembly 23 . The housing 22 may be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which are not particularly limited in the embodiments of the present application.

The electrode assembly 23 is a component in the battery cell 20 where electrochemical reactions occur. One or more electrode assemblies 23 may be contained within the housing 22 . The electrode assembly 23 is mainly formed by winding or stacking an anode pole piece and a cathode pole piece, and usually a separator body is provided between the anode pole piece and the cathode pole piece. The portions of the anode and cathode plates that contain active material constitute the main body of the electrode assembly, and the portions of the anode and cathode plates that do not contain active material each constitute tabs. The anode tab and the cathode tab can be located together at one end of the main body or respectively at both ends of the main body. During the charging and discharging process of the battery, the anode active material and cathode active material react with the electrolyte, and the tabs are connected to the electrode terminals to form a current loop.

According to some embodiments of the present application, please refer to Figures 4 to 5, and further refer to Figures 6 to 8. This application provides an isolation film roll 2000, including an isolation film body 231 and an early warning part 232. The isolation film body 231 has a head end a and a tail end b along the length direction F1 and is configured to be wound along the length direction F1. The warning portion 232 is provided on the isolation film body 231 and is configured to be spaced apart from the tail end b by a first preset length. L1.

The isolation membrane body 231 is a membrane with isolation function provided between the anode pole piece and the cathode pole piece in the electrode assembly 23 of the battery 100. The isolation membrane body 231 can be made of PP, PE or PI material, and the isolation membrane body 231 has electronic insulation. properties to ensure mechanical isolation of the anode pole piece and the cathode pole piece, and the isolation membrane body 231 has a certain pore size and porosity to ensure low resistance and high ion conductivity.

In the length direction F1, that is, the direction indicated by the arrow F1 in Figures 6 to 8, the isolation membrane body 231 forms a head end a and a tail end b at the opposite ends of the length direction F1. When along the length direction F1 of the isolation membrane body 231 It is wound to form the isolation film roll 2000 as shown in Figures 4 to 5, and its winding direction F1 is converted from the length direction F1. After the winding is completed, the first end a of the isolation film body 231 is located at a relatively outer position, and the tail end b of the isolation film body 231 is located at a relatively inner position. When the isolation film body 231 is peeled off from the isolation film roll 2000, The first end a is pulled and peeled off from the isolation film roll 2000 first, and the tail end b is then peeled off from the isolation film roll 2000, thereby completely peeling off an isolation film body 231.

The early warning part 232 is a structure used to provide an early warning to the tail end b of the isolation membrane body 231. It is provided on the isolation membrane body 231 and can be recognized by an external detection device. When the detection device recognizes the early warning part 232, The signal that the distance from the tail end b of the isolation membrane body 231 is still the first preset length L1 will be transmitted to the downstream device, prompting it to perform operations such as cutting, thereby giving an early warning to the tail end b of the isolation membrane body 231 Location.

The first preset length L1 is the length L1 marked in FIGS. 6 to 8 . The distance between the first preset length L1 can be related to the length of the cathode pole piece and the anode pole piece co-wound with the isolation film body 231 Sexual settings are not limited in this application. Through the control of the distance of the first preset length L1, sufficient time is given to the downstream device to operate, and the situation of belt breakage or tail end b caused by insufficient length of the tail end b during the high-speed winding process of the electrode assembly 23 is avoided. b The situation where the connected non-isolation film body 231 structure is directly wound into the inside of the electrode assembly 23 .

In this way, the warning part 232 warns the position of the tail end b of the isolation membrane body 231 in advance. When the warning part 232 is detected, it indicates that the tail end b of the isolation membrane body 231 still has the first preset length L1 at this time, so as to The position of the tail end b of the isolation membrane body 231 is predicted in advance and adjusted accordingly to avoid the belt breakage caused by insufficient length of the tail end b or the non-isolation membrane body 231 structure connected to the tail end b being directly wound to The internal conditions of the electrode assembly 23 ensure the quality of the electrode assembly 23 .

In some embodiments, the isolation film roll 2000 includes a plurality of isolation film bodies 231 , and every two adjacent isolation film bodies 231 are connected end to end through the connector 30 .

The connector 30 is a structure used to connect the tail end b and the first end a of two adjacent isolation membrane bodies 231. The original intention of its installation is to facilitate the connection of multiple isolation membrane bodies 231 and roll them into one to form an isolation membrane roll 2000. For storage or subsequent use, it is not part of the electrode assembly 23 and should not be wound into the electrode assembly 23. Conventionally, the connecting member 30 is made of insulating material, which can connect the tail ends b and the first ends a of two adjacent isolation film bodies 231 by fixed connection, adhesive connection, etc.

In some embodiments, a support member 40 may also be provided, and multiple isolation film bodies 231 are connected end to end and then rolled around the periphery of the support member 40 to form a quasi-cylindrical isolation film roll 2000 . The support member 40 may not be provided, and multiple isolation film bodies 231 may be stacked and rolled to accommodate more isolation film bodies 231 on the same isolation film roll 2000 .

In this way, by arranging the connecting member 30 , multiple isolation film bodies 231 can be wound simultaneously on one isolation film roll 2000 . At this time, through the setting of the early warning part 232, the specific position of the connecting member 30 can be known, thereby preventing the connecting member 30 between the isolation membrane body 231 and the isolation membrane body 231 from being wound to the high-speed winding process of the electrode assembly 23. This causes a defective electrode assembly 23 to be formed in the electrode assembly 23 .

In some embodiments, optionally, the connecting member 30 includes a tape adhesive formed of polyethylene terephthalate, which can adhere and connect the first end a and the last end b of two adjacent isolation film bodies 231 .

Polyethylene terephthalate is a common resin material. The tape formed by it has excellent physical and mechanical properties, friction resistance, dimensional stability and excellent electrical insulation. It can isolate adjacent The membrane body 231 is connected.

When multiple isolation film bodies 231 need to be wound onto the isolation film roll 2000, the multiple isolation film bodies 231 are connected and rolled to form an isolation film roll by pasting splicing tape at the connection position of each two isolation film bodies 231. 2000. When it is necessary to peel off the isolation film body 231 from the isolation film roll 2000, the warning part 232 is used to warn the position of the tape splicing glue in advance, prompting the downstream device to cut the tail end b of the isolation film body 231, so as to avoid the tape splicing glue being followed. The isolation film body 231 is wound into the inside of the electrode assembly 23, thereby affecting the production quality of the electrode assembly.

In some embodiments, each isolation membrane body 231 is provided with an early warning portion 232 .

The early warning part 232 is used to provide a position warning for the tail end b of the isolation membrane body 231 to avoid the situation of belt breakage due to insufficient length of the isolation membrane body 231 at the tail end b during the high-speed winding process of the electrode assembly 23. It is ensured that the tail end b position warning of each isolation film body 231 in the isolation film roll 2000 is provided, so that the tail end of each isolation film body 231 is effectively warned during the peeling process of the isolation film body 231 .

In some embodiments, the warning portion 232 is provided on the surface of the isolation film body 231, and the warning portion 232 extends along the length direction F1 and/or the width direction F2 of the isolation film body 231.

The width direction F2 of the isolation membrane body 231 is the direction indicated by the arrow F2 in Figures 6 to 8. The length direction F1 and the width direction F2 of the isolation membrane body 231 are perpendicular, so that the warning part 232 is in the width direction of the isolation membrane body 231. There is sufficient size in F2 and/or the length direction F1 to ensure that the warning part 232 can be detected by an external device.

In some embodiments, the warning portion 232 has a second preset length L2 in the length direction F1 of the isolation film body 231, and the second preset length L2 ranges from 10 millimeters (mm) to 50mm.

It can be understood that the isolation film roll 2000 is formed by winding along the length direction F1 of the isolation film body 231, and the isolation film body 231 is peeled off from the isolation film roll 2000 along the length direction F1 of the isolation film body 231, and the external The detection device is arranged on the peeling path of the isolation film body 231 to ensure that the second preset length L2 of the warning part 232 can have a sufficient detection distance when the warning part 232 passes the external detection device to ensure that the warning part 232 can be effectively detected.

In this way, the range of the second preset length L2 is controlled to be 10 mm-50 mm to ensure that the early warning part 232 can be effectively detected by the external detection device.

In some exemplary embodiments, the warning part 232 may extend to both sides of the isolation film body 231 in the width direction F2 of the isolation film body 231 , or may not extend to both sides and the warning part 232 may be disposed on the isolation film body. 231 in the middle.

In some embodiments, in the width direction F2 of the isolation film body 231 , at least one edge of the warning portion 232 coincides with the edge of the isolation film body 231 .

This embodiment includes the following three situations: in the width direction F2 of the isolation membrane body 231 , the left edge of the warning part 232 coincides with the edge of the isolation membrane body 231 ; the right edge of the warning part 232 overlaps with the edge of the isolation membrane body 231 The edges overlap; the edges on both sides of the warning part 232 overlap with the edges on both sides of the isolation membrane body 231 .

When both edges of the warning part 232 coincide with both sides of the edge of the isolation membrane body 231 in the width direction F2 of the isolation membrane body 231, then the early warning part 232 only needs to be disposed along the width direction F2 of the isolation membrane body 231. The manufacturing process is simple, and the early warning part 232 can achieve the function of being recognized by the detection device.

In some embodiments, the manufacturing process of the electrode assembly also includes identification of the status of the tab. Specifically, a folding sensor can be used to identify whether the tab is folded.

When the left edge of the warning part 232 overlaps the edge of the isolation film body 231 or the right edge of the warning part 232 overlaps the edge of the isolation film body 231 in the width direction F2 of the isolation film body 231 , the early warning part 232 The side that does not overlap with the edge of the isolation membrane body 231 can distinguish the position of the tab on that side, preventing the early warning part 232 from misjudgment when it passes the sensor that identifies the tab, that is, the sensor senses the early warning part 232 and mistakenly determines that it is an extreme. ear phenomenon.

It can be understood that the above embodiment is described with the isolation film roll placed vertically along the winding direction as an example, and the isolation film roll can be placed in other ways in actual applications.

In some embodiments, in the width direction F2 of the isolation membrane body 231 , the two side edges of the warning part 232 do not coincide with the two side edges of the isolation membrane body 231 .

It can be understood that the warning part 232 penetrates the entire isolation film body 231, which will cause the tab folding sensor that senses the tabs on both sides of the width direction F2 of the isolation film body 231 during the winding process to falsely alarm after recognizing the warning part 232. The pole ears are folded. Therefore, the pre-warning part 232 is located in the middle of the isolation membrane body 231 and does not extend to both ends of the isolation membrane body 231 in the width direction F2, and is positioned differently from the tabs located at both ends of the isolation membrane body 231 in the width direction F2, so as to further prevent early warning. When the part 232 passes through the sensor that identifies the tab, a misjudgment occurs, that is, the sensor senses the warning part 232 and mistakenly determines it to be the tab, thereby reducing false alarms during the production process of the electrode assembly and improving production efficiency.

In some embodiments, in the width direction F2 of the isolation membrane body 231 , the distance between the two side edges of the warning part 232 and the two side edges of the isolation membrane body 231 ranges from 5 mm to 30 mm.

The distance between the two side edges of the early warning part 232 and the two side edges of the isolation membrane body 231 can be equal. In this case, the early warning part 232 is located in the middle of the width direction F2 of the isolation membrane body 231. The distance between the edges on both sides of 231 may also be unequal. In this case, the warning part 232 is disposed toward one side of the isolation membrane body 231 in the width direction F2.

In the range of 5mm-30mm, it is ensured that the warning part 232 can be effectively detected by an external detection device, and at the same time, mutual influence between the warning part 232 and the tab can be avoided.

In some embodiments, the warning part 232 is a warning coating coated on the surface of the isolation film body 231 .

The early warning coating is a kind of pigment, glue or mixture coating, which is located on the surface of the isolation membrane body 231 and has properties that are obviously different from those of the isolation membrane body 231, such as the hue, lightness, chroma, glossiness and other parameters of the two surfaces. , so that the early warning coating can be accurately and easily detected by external detection devices.

The early warning coating can be directly coated on the surface of the isolation membrane body 231 to easily and quickly form the early warning portion 232 that can be detected by an external detection device without causing damage to the surface of the isolation membrane body 231 . Grooves or protrusions can also be formed on the surface of the isolation film body 231 . In some exemplary embodiments, a warning coating can be formed on the groove wall or the protrusion surface to ensure that the isolation film body 231 is peeled off during the process. , the early warning part 232 can be directly and quickly recognized by an external detection device.

In some embodiments, the color of the isolation film body 231 is different from the color of the warning part 232 .

Colored colors have three basic characteristics: hue, purity (also called chroma, saturation), and lightness. In color science, it is also called the three elements of color or the three attributes of color. A color with a saturation of 0 is an achromatic color system. For example, by coating the isolation film body 231 with an early warning coating that has a color difference from the isolation film body 231, thereby forming the isolation film body 231 and the early warning portion 232 with different colors, so that the early warning portion 232 serves as an early warning.

In a specific embodiment, the surface of the controllable isolation film body 231 is white, and the lower limit of the RGB value of the color of the early warning part 232 is set to (1,176,241) and the upper limit is (25,38,213) to ensure early warning. The color of the portion 232 can be clearly distinguished from the isolation film body 231, so that it can be recognized and produce an early warning effect.

In other embodiments, the surface of the isolation membrane body 231 can also be set to any color, and the surface of the warning portion 232 can be set to a color different from the surface of the isolation membrane body 231 , which is not limited in this application.

In some embodiments, the shape of the warning part 232 is rectangular, circular, semicircular, trapezoidal or triangular.

The rectangle, circle, semicircle, trapezoid or triangle can all form an extension in at least two directions, thereby ensuring that the warning part 232 has a second preset length L2 in the length direction F1 of the isolation film body 231 and along the width direction. F2 extends to both sides of the isolation membrane body 231 .

In this way, the shape of the warning part 232 is varied, which makes the processing operation of the warning part 232 simple and can realize the warning function.

In some embodiments, the warning coating includes a glue material made of rubber.

By applying adhesive material on the surface of the isolation film body 231, the warning part 232 is quickly formed. In some exemplary embodiments, 5# glue made of natural rubber can be used, which has a faster setting time and higher adhesion strength.

According to another aspect of the present application, a method for preparing an isolation film roll is also provided, wherein, referring to Figure 11, the preparation method specifically includes:

S10. Provide an isolation membrane body 231. The isolation membrane body 231 is formed with a head end a and a tail end b along its length direction F1;

S30. An early warning part 232 is provided on the isolation membrane body 231, and the early warning part 232 is configured to be spaced apart from the tail end b by a first preset length L1;

S50. Wind the isolation film body 231 along the length direction F1 to form an isolation film roll 2000.

The explanations of terms involved in the above and following methods have been explained in the above content and will not be described again below.

In this way, the position of the rear end b of the isolation membrane body 231 is warned in advance by the early warning part 232. When the early warning part 232 is detected, it indicates that the rear end b of the isolation membrane body 231 still has the first preset length L1 at this time, so as to The position of the tail end b of the isolation membrane body 231 is predicted in advance and adjusted accordingly to avoid the belt breakage caused by insufficient length of the tail end b or the non-isolation membrane body 231 structure connected to the tail end b being directly wound to The internal conditions of the electrode assembly 23 ensure the quality of the electrode assembly 23 .

In some embodiments, referring to Figure 12, providing the isolation membrane body 231 specifically includes:

S11. Provide multiple isolation membrane bodies 231, and every two isolation membrane bodies 231 are connected end to end.

In this way, multiple isolation film bodies 231 can be wound on one isolation film roll 2000 at the same time. Continuous winding and continuous peeling of the isolation film body 231 are realized, thereby improving production efficiency.

In some embodiments, referring to Figure 12, setting the warning part 232 on the isolation membrane body 231 specifically includes:

S31. An early warning part 232 is provided on each isolation membrane body 231.

In some embodiments, referring to Figure 13, two isolation membrane bodies 231 connected end to end also include:

S12. Connect the head end a and the tail end b of each two isolation membrane bodies 231 through the connecting piece 30 .

By providing the connecting member 30, multiple isolation film bodies 231 can be wound simultaneously on one isolation film roll 2000. At this time, through the setting of the early warning part 232, the specific position of the connecting member 30 can be known, thereby preventing the connecting member 30 between the isolation membrane body 231 and the isolation membrane body 231 from being wound to the high-speed winding process of the electrode assembly 23. This causes a defective electrode assembly 23 to be formed in the electrode assembly 23 .

In some embodiments, referring to Figure 14, connecting the head end a and the tail end b of each two isolation membrane bodies 231 through the connector 30 specifically includes:

S121. Provide polyethylene terephthalate to form a splicing tape to adhere the head end a and the tail end b of each two isolation film bodies 231.

When multiple isolation film bodies 231 need to be wound onto the isolation film roll 2000, a splicing tape is pasted at the connection position of each two isolation film bodies 231, thereby connecting the multiple isolation film bodies 231 and rolling to form an isolation film. Volume 2000. When it is necessary to peel off the isolation film body 231 from the isolation film roll 2000, the warning part 232 is used to warn the position of the splicing tape in advance, prompting the operator to handle the splicing tape, so as to prevent the splicing tape from winding up with the isolation film body 231. inside the electrode assembly 23, thereby affecting the product qualification rate of the electrode assembly.

In some embodiments, referring to Figure 15, setting the warning part 232 on the isolation membrane body 231 also includes:

S32. Apply an early warning coating on the surface of the isolation membrane body 231 to form the early warning portion 232.

The early warning coating can be directly coated on the surface of the isolation membrane body 231 to easily and quickly form the early warning portion 232 that can be detected by an external detection device without causing damage to the surface of the isolation membrane body 231 . Grooves or protrusions can also be formed on the surface of the isolation film body 231 . In some exemplary embodiments, an early warning coating can be formed on the groove wall or the protrusion surface to ensure that the isolation film body 231 is peeled off during the process. , the early warning part 232 can be directly and quickly recognized by an external detection device.

In some embodiments, referring to Figure 16, applying the early warning coating on the surface of the isolation membrane body 231 also includes:

S321: Apply the early warning coating along the length direction F1 of the isolation membrane body 231, and apply the early warning coating along the width direction F2 of the isolation membrane body 231.

The warning part 232 is made to have sufficient size in the width direction F2 and/or the length direction F1 of the isolation film body 231 to ensure that the warning part 232 can be detected by an external detection device.

In some embodiments, referring to Figure 17, applying the early warning coating on the surface of the isolation membrane body 231 also includes:

S3211. Apply an early warning coating with a second preset length L2 along the length direction F1 of the isolation membrane body 231. The second preset length L2 ranges from 10 mm to 50 mm.

In this way, controlling the second preset length L2 to range from 10 mm to 50 mm can provide a sufficient detection distance when the warning part 232 passes the external detection device to ensure that the warning part 232 can be effectively detected.

In some embodiments, referring to Figure 17, extending the early warning coating along the width direction F2 of the isolation membrane body 231 also includes:

S3212: Apply the early warning coating along the width direction F2 of the isolation membrane body 231 until the distance between the two side edges of the early warning portion 232 and the two side edges of the isolation membrane body 231 is in the range of 5 mm to 30 mm.

In some embodiments, referring to Figure 18, before applying the early warning coating on the surface of the isolation membrane body 231 to form the early warning portion 232, it also includes;

S20. An early warning coating is provided. The early warning coating includes a rubber material made of rubber.

In some embodiments, the color of the isolation film body 231 is different from the color of the warning part.

In the above embodiment, the method of arranging the early warning part 231 on the isolation membrane body 231 to provide early warning to its rear end b is also applicable to the cathode pole piece and the anode pole piece, and will not be described again in this application.

According to some embodiments of the present application, referring to FIGS. 5 to 7 , the present application provides an isolation film roll 2000 and a preparation method thereof. The isolation film roll 2000 is wound with a plurality of isolation film bodies 231 connected end to end. The isolation film bodies 231 are connected by tape glue. Each isolation film body 231 is provided with an early warning part 232 formed by 5# glue, so that the isolation film bodies 231 are peeled off and rolled in sequence from the isolation film roll 2000. Summarizing the process of forming the electrode assembly 23, the warning portion 232 on each isolation membrane body 231 provides an early warning of the position of the tape at the tail end b, so as to avoid the position of the tape being unable to be determined and being wound to the electrode assembly 23 Internal imagination. It can be understood that by warning the position of the tail end b of the last isolation membrane body 231 in advance, it is possible to avoid the breakage caused by the insufficient length of the tail end b when the last isolation membrane body 231 is peeled off and rolled into the electrode assembly 23 Condition.

The technical features of the above-described embodiments can be combined in any way. To simplify the description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, All should be considered to be within the scope of this manual.

The above-described embodiments only express several implementation modes of the present application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be noted that for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

An isolation film roll, wherein the isolation film roll includes:

An isolation film body having a head end and a tail end along a length direction and configured to be wound along the length direction to form the isolation film roll; and

An early warning part is provided on the isolation membrane body, and the early warning part is configured to be spaced apart from the tail end by a first preset length.
The isolation film roll according to claim 1, wherein the isolation film roll includes a plurality of the isolation film bodies, and every two adjacent isolation film bodies are connected end to end through a connecting piece.
The isolation film roll according to any one of claims 1 or 2, wherein each of the isolation film bodies is provided with one of the early warning parts.
The isolation film roll according to any one of claims 1 to 3, wherein the warning portion is provided on the surface of the isolation film body, and the warning portion is along the length direction and/or width of the isolation film body. direction extension.
The isolation film roll according to any one of claims 1 to 4, wherein the early warning part is an early warning coating coated on the surface of the isolation film body.
The isolation film roll according to any one of claims 5, wherein the early warning coating includes a glue material made of rubber.
The isolation film roll according to any one of claims 1 to 6, wherein the color of the isolation film body is different from the color of the warning part.
The isolation film roll according to claim 2, wherein the connecting member includes a splicing tape formed of polyethylene terephthalate to connect the first ends of two adjacent isolation film bodies through adhesion. and tail end.
A method for preparing an isolation film roll, wherein the preparation method includes:

An isolation membrane body is provided, and the isolation membrane body is formed with a head end and a tail end along its length direction;

An early warning part is provided on the isolation membrane body, and the early warning part is configured to be spaced apart from the tail end by a first preset length;

The isolation film body is wound along the length direction to form the isolation film roll.
The method for preparing an isolation film roll according to claim 9, wherein said providing the isolation film body specifically includes:

A plurality of the isolation membrane bodies are provided, and every two isolation membrane bodies are connected end to end.
The method for preparing an isolation film roll according to claim 10, wherein providing an early warning portion on the isolation film body specifically includes:

An early warning part is provided on each isolation membrane body.
The method for preparing an isolation film roll according to claim 10, wherein connecting each two isolation film bodies end to end specifically includes:

The head ends and tail ends of each two isolation membrane bodies are connected through connecting pieces.
The method for preparing an isolation film roll according to claim 12, wherein the connecting the head end and the tail end of each two isolation film bodies through a connector specifically includes:

Polyethylene terephthalate is provided to form a splicing tape to adhere the leading and trailing ends of each two isolation film bodies.
The method for preparing an isolation film roll according to any one of claims 9 to 13, wherein said providing an early warning portion on the isolation film body further includes:

An early warning coating is applied to the surface of the isolation film body to form the early warning portion.
The method for preparing an isolation film roll according to claim 14, wherein applying an early warning coating on the surface of the isolation film body further includes:

The early warning coating is applied extending along the length direction of the isolation membrane body, and the early warning coating is applied extending along the width direction of the isolation membrane body.
The method for preparing an isolation film roll according to claim 15, wherein applying the early warning coating along the length direction of the isolation film body further includes:

The early warning coating with a second preset length is applied along the length direction of the isolation membrane body, and the second preset length ranges from 10 mm to 50 mm.
The method for preparing an isolation film roll according to claim 15, wherein applying the early warning coating extending along the width direction of the isolation film body further includes:

The early-warning coating is applied along the width direction of the isolation membrane body until the distance between the two side edges of the early warning portion and the two side edges of the isolation membrane body ranges from 5 mm to 30 mm.
The method for preparing an isolation film roll according to claim 14, wherein before applying an early warning coating on the surface of the isolation film body to form the early warning part, it further includes:

An early warning coating is provided, and the early warning coating includes a glue material made of rubber.
The method for preparing an isolation film roll according to any one of claims 9 to 17, wherein the body color of the isolation film is different from the color of the warning part.